In-Situ Grouting at ID Nat'l Lab Radioactive Waste Mgmt Complex
James J. Jessmore; Brandt G. Meagher; K. Jean Holdren
Interim Completion Report for Phase 2 Operable Unit 7-13/14 In Situ Grouting
This report summarizes in situ grouting at the Idaho National Laboratory Site Radioactive Waste Management Complex. Remediation was implemented in accordance with the Record of Decision for Operable Unit 7-13/14 under the Comprehensive Environmental Response, Compensation, and Liability Act.
The authors recognize the following Idaho Cleanup Project staff for contributing to this Interim Completion Report for the OU 7-13/14 Phase 2 In Situ Grouting Project:
Kirk M. Green Stuart K. Janikowski Daniel D. Mahnami Joseph A. Anderson Leanne Hackney Virgil R. Morriss
Document Production Staff:
Stuart C. Hall
Ina M. Nordstrom
Lynda M. Nelson
The authors sincerely acknowledge all of the contributions to safely and successfully completing this project from Radioactive Waste Management Complex personnel and force account staff, without whom the work described in this report could not have been accomplished.
The authors also recognize the management and professional staff of Hayward Baker, Inc., who performed the in situ grouting operation described in this interim completion report.
Personnel from the U.S. Department of Energy, Idaho Department of Environmental Quality, and U.S. Environmental Protection Agency actively participated in making this project successful.
The authors are grateful to Guy Loomis, retired INL scientist, for his vision and commitment to developing a viable high-pressure grouting technology for treating buried waste, and the Department of Energy Environmental Management Office of Science and Technology Programs (EM-50) for sponsoring early development of this technology.
Interim Completion Report for Phase 2 Operable Unit 7-13/14 In Situ Grouting
The Idaho Cleanup Project (ICP) treated selected buried waste in Subsurface Disposal Area (SDA), a radioactive waste landfill at the Radioactive Waste Management Complex (RWMC), by in situ grouting (ISG). RWMC is within the Idaho National Laboratory (INL) Site, a federal facility managed by the
U.S. Department of Energy (DOE). Remediation occurred in accordance with the RWMC Record of Decision for Operable Unit (OU) 7-13/14 (DOE-ID 2008a). This report describes the context for remedial action, summarizes the work that was completed, and certifies that the ISG component of the selected remedy is operational and functional.
1.1 Purpose and Scope
ISG is one of several components of a multi-phase remedy. Because remediation of OU 7-13/14 will be ongoing for several years, the ISG Work Plan (DOE-ID 2010) requires that an interim completion report be prepared to provide a support document for reference in the future OU 7-13/14 comprehensive remedial action report. This report fulfills that purpose. The scope of this report is to describe implementation of the ISG, Phase 2 of the selected remedy. The attached compact disc (inside back cover) provides operational data, including drill log files for each insertion point and borehole summaries.
1.2 Regulatory Setting and Selected Remedy
The RWMC remedial action is part of the environmental restoration of the INL Site under the Comprehensive Environmental Response, Compensation, and Liability Act (CERCLA)
(42 USC § 9601 et seq.). The INL Site was placed on the National Priorities List (54 FR 48184) of hazardous waste sites in 1989. In 1991, DOE, the U.S. Environmental Protection Agency (EPA), and the Idaho Department of Environmental Quality (DEQ), collectively called the Agencies, signed a Federal Facility Agreement and Consent Order (DOE-ID 1991) outlining the remedial decision-making process and schedule for cleanup of the INL Site. The document identifies RWMC as Waste Area Group 7, and OU 7-13/14 is the designation for the comprehensive, final investigation and remediation of RWMC.
Cleanup actions selected in the OU 7-13/14 Record of Decision (DOE-ID 2008a) address all of Waste Area Group 7, with focus on the primary source of contamination within the area—waste buried in the SDA. Remedial actions specified in the Record of Decision address controlling the source—buried waste—and contaminants migrating from the source zone into the subsurface and the underlying Snake River Plain Aquifer. The five major components of the selected remedy (DOE-ID 2008a) are as follows:
Vadose Zone Vapor Vacuum Extraction and Treatment—Operate and maintain the existing extraction and treatment system throughout construction and beyond, if necessary, until remediation goals are met for vadose zone vapor concentrations.
Targeted Waste Retrieval—Retrieve 6,238 m3 of targeted waste and high-concentration organic solvent waste from a minimum of 5.69 acres of pit areas.
In Situ Grouting—In situ grout specified soil vault and trench areas with a cumulative area ranging from 0.13–0.2 acres.a
Evapotranspiration Surface Barrier—Prepare the site for a cap, then construct an infiltration-reducing evapotranspiration surface barrier over the entire SDA.
Long-Term Institutional Controls—Establish and maintain long-term surveillance, maintenance, monitoring, and institutional controls to operate and maintain post-construction components of the remedy, limit access, and enforce land-use restrictions.
Remediation will occur over approximately 20 years in three overlapping construction phases followed by a final phase invoking long-term institutional control (DOE-ID 2008b). In situ grouting composes Phase 2. Twenty-one explicit locations in the SDA with a cumulative area of 0.13 acres were grouted in accordance with the Record of Decision to reduce contaminant mobility in the interim until the cap is constructed under Phase 3.
1.3 Physical Setting
The INL Site is located in a remote region in southeast Idaho (see Figure 1), occupies approximately 2,305 km2 (890 mi2), and has been a national nuclear energy research facility since 1949. RWMC is in the southwestern quadrant of the INL Site. It encompasses approximately 72 ha (177 acres), comprised of the SDA (39 ha [97 acres]), Transuranic Storage Area (23 ha [58 acres]), and Administration and Operations Area (9 ha [22 acres]) (see Figure 2). In addition to the surface area occupied by RWMC, Waste Area Group 7 includes underlying media (i.e., the vadose zone and aquifer) to the extent that RWMC and its sources of contamination affect those media. The Remedial Investigation (Holdren et al. 2006) describes physical characteristics (e.g., geology and hydrology), flora and fauna, demography, cultural resources, and operational history for RWMC and the INL Site.
1.4 Operational Background
The SDA was created in 1952 for disposal of waste contaminated with radionuclides and hazardous chemicals. Waste was disposed of in unlined pits, trenches, and soil vaults within surface sediments and on Pad A (an abovegrade disposal area within the landfill) over 14 of the 39 ha (35 of the 97 acres) in the SDA. ISG targeted one soil vault and 20 locations within trenches.
Soil vault disposals occurred from 1977 to 1994 and typically involved high-radiation wasteb from INL Site generators. Though most soil vault waste is not transuranic,c some is mixed.d Installed in rows in the SDA, soil vaults are unlined, cylindrical, vertical holes drilled in surface soil. They range from 0.4 to 2 m (1.3 to 6.5 ft) in diameter and from 5.2 to 7.6 m (17 to 25 ft) deep. The SDA has 21 rows of soil vaults.
Trench disposals occurred from 1952 to 1981. By today’s standards, waste in trenches could be categorized as mixed waste; trenches in use before 1970 contain waste that could be categorized as transuranic wastee or mixed waste. Trenches were excavated with nearly vertical sides. Trench lengths range from approximately 107 m (350 ft) to almost 549 m (1,800 ft) with a nominal width of 1.8 m (5 ft) and depths generally ranging from 5–10 ft. The SDA contains 58 trenches.
Figure 1. The Idaho National Laboratory Site.
Figure 2. Radioactive Waste Management Complex.
The Phase 2 Remedial Design/Remedial Action Work Plan for Operable Unit 7-13/14 (aka the Phase 2 Work Plan) (DOE-ID 2010) provided remedial design and planning for ISG. DOE funded Phase 2 ISG under the American Recovery and Reinvestment Act (Public Law 111-5) with the goal to complete fieldwork by 2011. To accommodate schedule constraints, the Agencies agreed that preparation for ISG could begin before the Work Plan was published but, ultimately, must meet Work Plan requirements. Therefore, many critical tasks, which included procuring an ISG subcontractor, refining system design and operational parameters, and preparing infrastructure at the SDA, were completed in parallel with developing the Phase 2 Work Plan. Success of this approach depended on frequent communications with the Agencies, a flexible protocol for identifying and implementing operational refinements, and maturity of ISG technology.
2.1 Performance Objective
Because the selected remedy for the SDA primarily is a source control action, the Record of Decision defined performance objectives, rather than contaminant-specific concentrations, as cleanup levels. The purpose of ISG is to reduce mobility of releasable fission and activation products (e.g., Tc-99 and I-129) in the interim until the surface barrier is constructed over the SDA. The performance objective specific to the ISG component of the selected remedy is based on the volume of grout injected into each treatment location. The performance objective is to exceed 80% of the maximum potential volume at each of the 21 ISG sites.
Quantities of grout injected and returned to the surface were recorded and evaluated against depth to basalt (to a maximum depth of 25 ft at soil vault locations and 17 ft in trench locations) and dimensions of the grouted area. Depth to basalt was determined in the field by recording each insertion depth and interpolating between insertion points without adjustments for refusal. If basalt was not encountered, nominal depths of 25 and 17 ft were applied in soil vault and trench locations, respectively. To calculate the maximum potential volume after treatment was applied, the site-specific grout capacity was estimated. If the injected grout volume was within 20% (i.e., exceeds 80%) of the maximum potential volume, grouting was deemed effective and complete.
2.2 Remedial Design
ISG is a mature technology with a substantive basis for application in the SDA. Remedial design for OU 7-13/14 adopted the existing engineering basis presented in the Phase 2 Work Plan. The project strategy involved procuring the services of a qualified grouting subcontractor to supply and inject grout in the SDA. Procurement paralleled refinements to system design and operations, site preparation, and production of the Phase 2 Work Plan. Recommendations and requirements for ISG system design elements, operating parameters, and grout formula were compiled from research and development performed at the INL Site between 1985 and 2004. Because site-specific treatability studies demonstrated advantages of slag/cement mixtures for reducing hydraulic conductivity, immobilizing contaminants, and implementing in the field, slag/cement grout comprising a 50:50 mixture of Portland cements and granulated blast furnace slag was required.
Disposal records and geophysical mapping tools were used to (1) identify and select waste shipments for ISG and (2) determine accurate locations. SDA disposal records were reviewed and analyzed to identify waste streams that have Tc-99 in the most releasable forms, as described in the OU 7-13/14 Record of Decision (DOE-ID 2008a). Releasable I-129 is collocated with Tc-99 in these same waste streams. Using geophysical data, each candidate location was analyzed to validate and finalize location design, including buffers within the perimeter of each ISG site. Figure 3 shows final locations of the 21 ISG sites within the SDA. ISG sites are labeled with respect to their corresponding trench or soil vault row. Multiple ISG sites in the same trench are labeled with a letter, beginning with “A,” and assigned from west to east (from left to right on a map) or north to south (from top to bottom on a map).
2.3 Remedial Action Work Plan Requirements
The Phase 2 OU 7-13/14 ISG remedial action was performed by a qualified grouting subcontractor, Hayward Baker Geotechnical Construction, Inc. (HBI), with oversight and construction support from CH2M-WG Idaho (CWI). HBI performance requirements were stipulated in a construction specification (SPC-1162) developed in accordance with design requirements set forth in the Phase 2 Work Plan (see DOE-ID 2010, Section 184.108.40.206). Each requirement was met. Table 1 presents a performance matrix for each requirement. The requirements are arranged into two categories, equipment and operational requirements and implementation requirements. For each requirement, the matrix identifies project references, a method of verification, and clarifying notes.
The following subsections separate equipment and operational requirements into the following elements:
- Section 2.3.1—Plans and Procedures
- Section 2.3.2—Equipment and Personnel
- Section 2.3.3—Drilling and Grouting Operations.
Section 3.6, Remedial Action, gives more details on compliance with implementation requirements.
2.3.1 Plans and Procedures
The following plans and procedures were prepared to execute ISG in the SDA:
- A hazard assessment to evaluate the safety envelope for the project and to determine the appropriate project hazard classification
- An assessment of project preparedness to commence operations
- General health and safety documentation required to identify and mitigate hazards and prevent injury or exposure to personnel
- Other documentation necessary to clarify and document roles and responsibilities
- General ISG operational documents to determine performance.
This section also describes the protocol used to manage project records.
220.127.116.11 Hazard Assessment. A hazard assessment (HAD-460) was prepared as an early step in implementing a graded approach to nuclear safety management for Phase 2 ISG as required by 10 CFR 830 Subpart B, Appendix A, Paragraph F. The graded approach required that the level of analysis be commensurate with the importance to safety, magnitude of hazard, and life-cycle stage and programmatic mission of the facility. The ISG Project was segmented for hazard categorization from the rest of the RWMC and performed as an independent activity, physically separated from other RWMC activities. The hazard assessment and hazard categorization, documented in HAD-460, were performed for ISG as a segmented activity in the areas in which grouting was performed (DOE-STD-1027-92). The segmented areas include all the grouted sites. The assessment evaluated consequences of hazards for ISG operations and concluded that the ISG Project was a less than Hazard Category 3 radiological project. DOE approved the assessment, and it was provided to the nuclear facility manager on December 2, 2009.
Figure 3. Locations of the 21 in situ grouting sites treated under Phase 2.
18.104.22.168 Management Self-Assessment Plan to Determine Operational Readiness. ICP elected to develop and implement a management self-assessment (MSA) plan (PLN-3456) to assess readiness for ISG in the SDA. An independent team of ICP cognizant professionals conducted this optional assessment to confirm readiness to start operations. The scope of the assessment included reviewing requirements for treating ISG sites and affirming that those requirements were adequately implemented. The assessment was performed from May 24 to June 3, 2010.
Following satisfactory completion of all elements of the plan and resolution of pre-start findings, the management team affirmed readiness to commence operations in the SDA (see Section 3.4).
22.214.171.124 Health and Safety and Operations. Construction support and operation of ISG systems presented task-specific physical, chemical, and radiological hazards to both ICP and HBI personnel. These hazards were identified via formal pre-planning (e.g., job walkdown, review of lessons learned, and completion of hazard profile screening checklists) and lessons learned from the 2001 grouting incident and the 2004 beryllium block project and incorporated into job-specific work control documents, pre-job briefings, and training to work control documents. In addition, full-time safety, industrial hygiene (IH), and Radiological Control (RadCon) technicians oversaw the work and applied designed engineering controls and real-time monitoring of selected contaminants to mitigate potential hazards and exposures.
126.96.36.199.1 Project Health and Safety Plan—A project-specific health and safety plan (PLN-3412) was prepared by CWI to meet Occupational Safety and Health Administration (OSHA) standards contained in the Hazardous Waste Operations and Emergency Response (HAZWOPER) requirements (29 CFR 1910.120, “Hazardous Waste Operations and Emergency Response,” and 29 CFR 1926.65, “Hazardous Waste Operations and Emergency Response”).
188.8.131.52.2 Work Documentation—Project hazard controls and mitigation measures were defined in two ICP STD-101 work orders developed for the project. The first (Q628544) directed ICP construction support crews in site preparation, post-grouting restoration of the ISG sites, and support of the ISG operation (e.g., relocation of barriers and postings, placement of soil for radiation control).
The second (Q626247) directed HBI and ICP support personnel in the performance of initial equipment surveys and inspections, mobilization and equipment testing at the Cold Test Pit-South, mobilization of equipment inside the SDA, drilling and grouting of specified ISG sites, decontamination and demobilization of equipment, and performance of final inspections. Subcontractor work also was directed by operational plans and a project job safety analysis, prepared by HBI, which were included in the work order by reference.
As specified in the CWI subcontract specification (SPC-1162) and required in the Phase 2 Work Plan (DOE-ID 2010), HBI developed a Drilling and Grouting Plan prior to initiating fieldwork. Plan submittals were managed through the CWI vendor data system. The plan prescribed operational protocols necessary for achieving the ISG performance objective (see Section 2.1). The Drilling and Grouting Plan was submitted to DEQ for review and was accepted as final on March 8, 2010. After the start of fieldwork, the plan was revised to accommodate necessary operational changes. The content of these changes was discussed via an Agency conference call on July 27, 2010, and the plan was subsequently modified and submitted to DEQ for formal review on August 8, 2010, and approved on August 10.
Table 2 identifies changes associated with each document revision.
Daily ISG operations conducted by HBI were directed by the RBI Operations and Management Plan, which was managed through the CWI vendor data system and referenced in the ISG applicatio11 work order. Over the course of the p project , this document was revised five times to accommodate operational changes. The original plan and the first revision were each issued during the project system design phase in preparation for HBI' s offsite demonstration. Following the offsite demonstration, the second revision was issued in c01porati ng lessons learned from the demonstration. The third revision was issued following the MSA and onsite demonstration. Revision 4 of the plan, initiated by DOE-ID facility representative concerns involving personnel contact with the monitor and nozzle, instituted a significant operational change, requiring work on the monitor and nozzle to be conducted with the drill rig turned off and the ignition key placed under control. Because of the significance of th s and other changes included in the plan revision, personnel received documented tailgate training on July 20 20 I 0. The plan underwent a fifth revision to accommodate steps for subsurface flushing. The content of this change was discussed via an Agency conference call on July 27, 2010, and the plan was subsequently modified and approved August 5, 2010. Table 3 identifies changes associated with each document revision.
In compliance with the CWT subcontract specification (SPC-116 2), a Grout Formulation Plan (VDR-29684 I) was developed by RBI prior to initiation of fieldwork. Submittals were managed through the CWI vendor data system. The Grout Formulation Plan identified the binder material selected for the INL Site ISG project as a 50/50 by weight cement/slag mixture. The cement was a Portland Type I-II Low Alkali cement manufactured according to ASTM C-15 0 standards.. The slag material was a ground granulated blast furnace slag manufactured to meet the requirements of ASTM C-989 and AASHTO M302. The cement/slag mix was selected based on previous studies conducted at the INL Site. The studies showed that the higher density of cement/slag mixtures improved monolith integrity by imparting more energy into the buried waste and components of the grout improved chemical fixation compared to additional cement water grouts.
Ash Grove Cement Company provided the dry cement and slag materials , which were blended by HBI subtler vendor Handy Wholesale Products of Burley, ID. The two materials were delivered to the plant and stored in separate silos. Both of the materials were auger-fed, in equal proportions, into a weigh bin, blended for 2 minutes using a rotary mixer , then sample d to verify consistency. Following inspection, the dry mix was containerized in 2,000- Lb bulk sacks for delivery to the INL Site and stored in designated laydown areas adjacent to the ISG sites. Adherence to the HBI's quality standards was verified by CWI quality inspectors prior to fie ld operations starting.
The grout mixtiure also contained superplasticizer to minimize caking in the high-pressure system.
The superplasticizer, Eucon 37, manufactured by Euclid Chemical , complies with the standard requirements of ASTM C-949 Type A&F admixtures and AASHTO Ml94. Eucon 37 was introduced into the grout mixture in liquid form. The grout was mixed using an AD I0/10 high-shear colloidal mixer with 74-gal capacity . The mix consisted of the 50/50 slag/cement mixed with water, at a ratio of 1:1 by weigh t, and plasticizer. Each batch consisted of 400 lb of binder material (i.e ., d1y cement/slag mixture), 48 gal (400 lb) of water, and 10-20 oz of plasticizer. Each batch yielded approximately 64 gal of grout with a specific gravity of I .50 (with an acceptable range from I .40 to I. 70).
184.108.40.206 Project Interface Agreement- Waste Disposition Plan. A Waste Disposition Plan (PLN-3497) was developed by Waste Generator Services (WGS) to act as an interface agreement between the generator, the Phase 2 OU 7-13/14 ISG Project, W GS, and the Idaho CERCLA Disposal Facility (ICDF). The plan outlined the expected waste streams, disposition of these waste sh-earns, management of the waste, disposal path(s) for these waste streams, and roles and responsibilities. WGS provided daily assistance to the project with the characterization, packaging , storage , and recordkeeping associated with the project waste streams. Following completion of project demobilization, WGS oversaw the shipment and disposal of the project waste streams. Waste from the ISG Project was managed in accordance with PLN-3456, WGS, and company protocols (see Section 4).
220.127.116.11 Records Management. Document and Records Management organizations controlled and managed documents and records in accordance with ICP management control procedures (MCP-135 and MCP-557). Reports generated by field activities, project plans, the project health and safety plan, and other documents and records pertaining to these operations either are maintained in an electronic document management system or were sent to records storage . TCP ' s vendor data process (MCP-3573) was used to control acquisition of supplier and subcontractor documents to ensure that those documents were technically correct and available for engineering, construction, operations , and maintenance activities. The process was applied to all processing related to vendor data, including specifying required vendor data, acquiring, reviewing, and archiving as a record.
2.3.2 Equipmentand Personnel
In accordance with the project specification (SPC-1 I 62), HBf furnished all material , equipment, tools , documentation , supp li es, and personnel necessary to drill and emplace grout in the 21 TSG sites . Because of significant safety concerns associated with the ISG operation, HBI was required to follow a prescribed design, verification, and testing protocol with a project-specific personnel training regime before mobilizing to the INL Site.
18.104.22.168 Equipment Design and Verification. HBI deployed two complete jet-grouting systems to complete the project scope in one field season. Both systems, identified in the field as Rig #1 and Rig #2, were identical with the exception of the binder silo and transfer mechanism . The system design had both a high-pressure and a low-pressure leg. Primary high-pressure components consisted of the mon it or, swivel, and rotary percussive head, all of which traveled vertically on the mast of the excavator-mounted drill 1ig. Attached to the side of the excavator was a rigid slick Line for grout transfer over the tracks . A 1-in.-diameter high-pressure hose connected all components supplying grout from the triplex pump . All high-pressure components from the outlet of the triplex pump through the single fluid monitor were purchased new for this project or were subjected to verification testing to ensure they met high-pressure system design criteria. The low-pressure leg , responsible for grout mixing and transfer to the high-pressure pump, consisted of a portable diesel-driven hydraulic batch plant, which received binder material via auger or screw conveyor from a raw product silo . Ancillary equipment included two 125-kW generators that supplied power to the triplex pumps. Water for grout mixing and flush operations was supplied by an onsite 6,900-gal poly tank and a Low-pressure gasoline-powered pump. The water was transported from the WMF-602 Fill Station and transferred to each tank via a 4,000-g al-capacity water truck , which supported both rigs. Binder material delivery and handling for both systems were supported by a 10,000- lb-capacity all-terrain forklift. Table 4 describes each primary system component, with manufacturer and basic operating parameters.
Because of the significant safety concerns associated with the high-pressure leg of the system, HBT was required to develop a Pressure Design Rep01t (VDR-301030) that was reviewed and approved by an independent design professional and stamped by a professional engineer registered in the State of ldaho.
The submittal was then managed through the CWI vendor data system. The report documented all design aspects of the pressurized components and stated the following: engineering codes and standards used in the design, traceability for each component (i.e., examinations and inspections of materials, in-process fabrications, nondestructive tests, and acceptance tests), maximum and operational rated system pressures; the report also included documentation (i.e., catalog cuts, calculations, vendor correspondence) that every component was qualified to operate at the rated pressures. The design also detailed pressure relief components and addressed parts assemblies and component calibration requirements.
Following acceptance of the system design and assembly of the system, HBI was required to submit, via the CWI vendor data system, a Pressure Design Verification Report (VDR-303383), which documented hardware compliance with the design. This report also required the stamp of a registered professional engineer. It documented that (a) all pressure components were assembled and installed pursuant to the manufacturer’s recommendations, were tested and marked, and had material traceability to recognized standards and (b)installed components were compliant with the rated system pressures and temperature. It also documented that the redundant pressure relief systems had been both calibrated and verified to open at no more than the rated pressures. Figure 4 contains detailed component and assembly information on the high-pressure leg of the system.
Following hardware verification by HBI and an independent professional engineer, an operational system pressure and grout operations test was required prior to mobilization of the system to the INL Site. Testing was performed to a Component Checkout/System Operational (CC/SO) Test Plan
(VDR-3005680, which was developed by HBI and managed through the CWI vendor data system. In accordance with the project specification (SPC-1162), testing included a full mockup of the actual application scenario inclusive of simulated SDA waste, RadCon and safety controls, and conduct of operations. These tests provided the CWI project team an opportunity to verify functionality of all aspects of the system (e.g., safety systems, data acquisition, positioning, and rotary percussion drilling), to observe the adequacy of HBI’s operating procedures and their interface with CWI STD-101
(Work Order 626247) work documents, and to observe the resultant grouted simulated waste zone. Representatives of the CWI Quality organization verified HBI’s compliance with their Quality Project Plan (VDR-290723). The project team trained HBI personnel to standard RadCon and INL Site work protocols. Members of the CWI field team, consisting of Engineering, Safety/IH, RadCon, Operations, Quality, and the nuclear facility manager, were present to gain experience with the ISG system and operating procedures. CC/SO testing was conducted at HBI’s facility located in Santa Paula, CA, on April 14, 2010, and also was attended by DOE and DEQ representatives.
22.214.171.124 ISG System Component Description and Function. The ISG Project used two separate ISG systems. Each system contained four critical components and several ancillary support systems. The four critical components were:
- Drill rig
- High-pressure pump
- Batch plant
- Data acquisition system (DAS).
Figure 5 shows a typical site layout with relative positioning of critical components and ancillary support systems.
Figure 4. Detailed component and assembly information on the high-pressure system.
Figure 5. Typical in situ grouting site configuration
126.96.36.199.1 Drill Rig—HBI selected the Klemm KB 2510 hydraulic excavator-type drill rig for the ISG application because of the rig’s ability to deploy the mast into each ISG site without the platform or tracks crossing contamination boundaries. The drill rig had a maximum reach of 12 ft and was capable of drilling to a maximum of 17 ft below ground surface (bgs) for all trench locations and 25 ft bgs for the soil vault. Computer-controlled hydraulics maintained the preprogrammed drilling parameters and allowed on-the-fly modifications with push-button control. The boom was of sufficient length to support a 44-ft mast with a continuous drill string assembly, allowing for a heavier swivel and monitor and minimum tool joints to improve drive energy transmission and precluding the need for routine personnel interaction during drilling operations. The boom attachment allowed the operator to rotate the mast up to 90 degrees to better observe the swivel, rod, and monitor during operations and accurately position the drill string. Near the base of the mast was a hydraulic arm for mounting a tool to break pipe connections and a set of hydraulic jaws to hold the monitor while completing connections. Safety systems included an automatic pump shutoff system that activated if retraction depth exceeded a 4-ft-bgs set point, a system hydraulics lock-out lever, a green (“green for go”) signal light to communicate when system hydraulics had been locked out and it was safe to approach the rig, a high-pressure pump kill switch, bend radius protectors and whip socks on all connections, a 1-in. slick line for safely transferring grout via hard pipe over excavator tracks, and warning labels. Figure 6 shows the Klemm KR2510 excavator-mounted drill rig and its primary features.
Components mounted to the traveling head connected to the mast comprised the Krupp HB 50 A hammer drill, capable of producing adjustable percussive energy and rotary drilling drive, and the swivel manufactured by OCI Division of Global Drilling Suppliers, Inc., designed to allow grout to flow from a fixed hose through to the rotating drill rod. Connected to the bottom of the swivel was the monitor, also manufactured by OCI, designed to transfer the grout flow from vertical to horizontal at the point the fluid is injected into the ground. The monitor was just over 20 ft long, 3.5 in. diameter, and 1.25 in. wall thickness. It had provisions for two offset 2.4-mm jets located approximately 5.75 in. above the bottom of the bit, one angled down 15 degrees and the other, located slightly below, set horizontal. The project was conducted with the horizontal nozzle port and never used the angled port. Grout flowed through the 1-in. center of the monitor and out a single nozzle. The drill string (monitor and bit) was of continuous design, with a flush joint and undersized bit, to avoid creating an annulus during drilling, which would be a preferential pathway for grout returns. The 3.13-in. step bit was designed to penetrate hard soil and withstand minor amounts of milling. Figure 7 shows the rotary percussive head and swivel on the traveling head of the drill rig mast, the bit, and the nozzle port near the end of the monitor.
Figure 6. Excavator-mounted drill rig
Figure 7. Rotary percussive head and swivel on traveling head of mast, drill bit, and end of monitor.
In accordance with the project specification (SPC-1162), the system was to be equipped with drill-string contamination-control hardware. Prior to construction, the HBI’s design was submitted through the CWI vendor data system and was thoroughly reviewed by RadCon and safety professionals.
The shield assembly mitigated the potential spread of contamination as the drill string was lifted from an insertion point, as it moved positions, and it was inserted into a position. The shield assembly was supported over the immediate area of the hole being drilled by an enclosed foot at the base of the mast. The assembly included a top sleeve, which contained a set of heavy-duty wipers to remove the grout from the drill string as it was withdrawn through the plate, and a spray head. The spray head was supplied from a reservoir and pump mounted on the rig, which applied a coating of fixative to the rotating monitor as it was withdrawn. CWI RadCon personnel fabricated a heavy drawstring sack that was placed over the entire assembly for transport of the rig between ISG sites. In addition, RadCon personnel routinely covered the hydraulic jaws with plastic for additional protection. The entire assembly was bolted to the base of the mast, below the jaws, and was designed to be removed and discarded at the completion of the job. Figure 8 shows the contamination control hardware mounted on the base of drill rig mast.
The driller positioned the drill string from inside the cab with the built-in inclinometer for vertical mast alignment and a Leica RKS Total Station with preprogrammed insertion point coordinates. The Klemm excavator was equipped with various transducers to provide input to the data logger to monitor and record required parameters during drilling and grouting operations. Components supplying information to the DAS were managed in HBI’s calibrated equipment program, which tracked calibration status of each instrument (gauge, flow meter, thermocouple, flow totalizer, etc.) to standards traceable to the National Institute of Standards and Technology. Figure 9 shows the cab-mounted or handheld remote positioning sensor and Leica RKS Total Station.
188.8.131.52.1 High-Pressure Pump—The pump selected for the ISG Project was a
YBM SG-75 MK III high-pressure jet grout pump. The pump was an electric, triplex plunger pump that provided up to 7,250 psi maximum pressure and continuous working pressure of 5,800 psi. It required a 100-kVA power source, which was supplied by the onsite generator. The pump was equipped with two automatic overpressure relief systems: the primary system consisting of an electronic safety device and manual pressure relief valve and the secondary system consisting of a mechanical pressure relief valve (see Figure 10). The primary electronic safety device was set with a dial switch. When the pressure setting of 6,000 psi was reached (the upper end of the operating range), the switch shut the electric supply to the pump motor, and a pressure relief valve was manually opened. Pressure was relieved by diverting grout through a diversion elbow into a deflection box mounted on the rear of the pump skid. The secondary mechanical device was set by inserting a shear pin into a given location. When the system reached 7,100 psi ± 300 psi pressure, the shear pin failed and the grout was diverted through a diversion elbow to the deflection box. In the event of primary failure, pressure was able to be safely increased in the system to activate the secondary protection feature. All system components were rated at or above the 7,100 ± 300-psi pressure. In addition to the built-in safety features, the drill operator had an emergency shutoff switch in the cab. Lines of communication were maintained between the driller and pump operator, who also had an emergency shutoff switch on his controls. In the event of a catastrophic pump failure, the fluid end of the pump was outfitted with a shield that covered the pump output. This shield was designed to keep the pump operator safe if the pump discharge fittings should fail. Figure 11 shows the high-pressure pump skid and a closeup of the primary safety features.
The hose that connected all components of the high-pressure system was Spirablast 25k, manufactured by Markwel, and came in 50-ft lengths with 1-in. National Pipe Thread fittings. The rated pressure of the hose was 10,000 psi. Bend restrictors were designed into the system to ensure the 13-in. minimum bend radius, recommended by the manufacturer, was not exceeded. Hose sections were connected using 10,000-psi-rated hammer unions supplied by National Oilwell Varco. All hose connections were protected with American West Drilling Supply whip socks (Figure 12) to restrain the hoses in the event of a failed fitting. System pressures were monitored by a primary dial gauge, a lollipop gauge, and the in-cab computer screen.
184.108.40.206.2 Batch Plant—To mix the grout, a batch plant comprising an AD 10/10 high-shear colloidal mixer and low-pressure pump coupled with a super sack silo was selected. The batch plant was powered by a 65-hp diesel motor; the plant was capable of batching a maximum of 74 gal in the mixing tank and storing a maximum of 198 gal in the holding tank. The mixing plant supplied grout to the high-pressure pump under low pressure (240 psi) and flow (38 gpm). The batch plant was partnered with a super-sack silo and hydraulic auger delivery system to supply the binder material for mixing. Binder delivery to the mixer was metered on a weight basis, controlled by a readout from four load cells. Binder material was introduced into the silos by personnel emptying 2,000-lb super sacks using an all-terrain forklift. Prior to lifting, the sacks were prepared for unloading by placing them on a staging platform.
Figure 13 shows the batch plant and unloading operation.
Figure 8. Contamination control hardware mounted on the base of the drill rig mast.
Figure 9. Cab-mounted and handheld remote positioning sensor and total station.
Figure 10. Automatic overpressure protection and relief system diagrams: primary electronic safety pressure switch and manual pressure relief and the secondary mechanical pressure relief device.
Figure 11. High-pressure pump skid and primary safety features.
Figure 12. Whip socks installed on hammer union and high-pressure pump hose connections.
Figure 13. Batch plant and super sack unloading.
220.127.116.11.1 Data Acquisition System—The DAS that was implemented for the ISG Project allowed the parameters for rotation, step size, and rotations per step to be input into a computer and controlled automatically. From these values, the driller was able to drill to total depth, press a button on the computer screen in the cab of the drill rig, and allow the computer to control the grouting operation. The DAS was also capable of recording the grouting data. A series of sensors recorded grout pressure, duration, depth, withdrawal rate, revolutions per minute (rpm), specific gravity, volume, and treated length.
18.104.22.168 Project Personnel. The reporting structure for field personnel involved in the ISG Project is shown in Figure 14. This structure was in effect during execution of field activities. During project design and preparation, Environmental Restoration project management reporting was provided to Director Frank Webber and was transitioned to the RWMC ISG Operations Director, Allen Nellesen, during the MSA for the operational phase of the project. Both directors reported directly to Hoss Brown, vice president of the Accelerated Retrieval Project (ARP)/Environmental Restoration Project.
Figure 14. Functional organization chart during fieldwork.
The ISG project manager was responsible for the overall work scope, schedule, and budget and ensured that activities were conducted in compliance with applicable ICP and OSHA processes and procedures and met the requirements set forth in the Phase 2 Work Plan (DOE-ID 2010). The project engineer led and directed the engineering and design activities for all aspects of the project. Activities included the review and approval of vendor data, operations procedures, system CC/SO testing. The project engineer also ensured work was performed to acceptable technical standards in accordance with the project’s technical and functional requirements.
Because this project was managed as an ICP Construction project, a subcontractor technical representative (STR) was appointed to coordinate field activities and provide direction and oversight to the subcontractor. The STR also bridged administrative and technical roles and responsibilities, serving as the field representative for the subcontract administrator. The STR conducted pre-job briefings before beginning work, addressing the day’s activities, associated hazards, hazard mitigation (e.g., engineering and administrative controls, required personal protective equipment, and work control documents), and emergency conditions with input from the project health and safety officer, RadCon technician, and HBI. Fieldwork required equipment operators, laborers, or other crafts for site preparation and restoration activities that were separate from the ISG operations, so a job site supervisor directed and supervised this crew.
ICP RWMC RadCon, IH, safety, quality assurance, and WGS professionals provided direct oversight for all ISG field activities. Environmental Restoration Project support personnel, who were involved with the project from the inception, continued to oversee field activities. Two health and safety officers were required to be onsite while conducting field activities, one provided by HBI and the other by CWI.
HBI staffing requirements to drill, grout, and perform ancillary work included those personnel identified in Figure 15; duplicate personnel positions, from the drill rig operator down were required only when two systems were in operation. The forklift operator, along with a batch plant assistant, supported both operations with grout product delivery. The health and safety officer oversaw the operation of both systems as well.
Figure 15. Hayward Baker, Inc., field staff and organization chart.
The superintendent was responsible for ensuring the safe and successful completion of field activities for HBI. The superintendent contributed to pre-job briefings before beginning work, identifying site-specific activities and personnel assignments. While in the field, he monitored the mechanical systems, oversaw repairs, and directed routine maintenance. He also served as the health and safety officer representing HBI and was the primary interface with the CWI STR. The field engineer was involved early in the project and led and directed all aspects of the engineering functions. This included the production and submittal of pre-mobilization vendor data items, including system designs and verification reporting, development of operations procedures, system CC/SO testing and reporting,
and ensuring work was performed to required technical standards in accordance with the subcontract specification (SPC-1162). While in the field, the field engineer monitored and ensured the performance of the data acquisition and total station positioning systems and the automated drilling/grouting control system. He also prepared and submitted required daily production reporting. Mechanical and electrical system repairs were supported by an onsite technician. A driller was positioned in the cab of each drill rig and controlled all aspects of the drilling and grouting at each ISG site. Through direct radio contact, the driller directed both the production and supply of grout to the drill rig. He was also responsible for drill string positioning, controlling drilling functions to safely and efficiently penetrate the heterogeneous waste seam, and controlling grouting parameters based on grout returns observations. Such decisions were also supported by the CWI project engineer. The pump operator and batch plant operator were responsible for maintaining their respective system components and taking direction from the driller during ISG operations. The batch plant operator had the added responsibility for measuring and maintaining quality records on grout batches. The ground man aided the driller by observing and communicating drilling and grouting conditions from various vantage points around the rig and ensured that high-pressure hoses were positioned away from the excavator tracks during repositioning maneuvers.
2.3.3 Drilling and Grouting Operations
Drilling and grouting operations were accomplished with two independent drilling and grouting systems, referred to in the field as Rig #1 and Rig #2. System moves within the SDA were optimized so that, to the greatest extent possible, only the excavator-mounted drill rig was mobilized between ISG sites, while the grout batch plant, high-pressure pump skid, and ancillary support equipment remained stationary, supplying grout via extended hose runs. ISG application by one rig at a given population of ISG sites is referred to as a “stage,” the term “stage” referring to the restaging of support hardware. ISG operations were completed in six stages: two ISG application stages for Rig #1 and four stages for Rig #2. Figure 16 gives the location of each stage, with the associated treated ISG sites and placement of the mixing and pumping support hardware.
22.214.171.124 Operational Schedule. Production was scheduled to begin with the eight waste trenches located farthest west (Rigs #1 and #2, Stage 1). Both drill rigs were deployed to this area to complete the waste trenches as quickly as possible and avoid impacting ongoing ARP VII construction activities; Rig #1 was deployed on June 7, 2010, and Rig #2 was deployed on June 18, 2010. The final westernmost site, T53A, was completed by Rig #1 on July 16, 2010, and, following backfill of the site on the July 21, control of the area was turned over to ARP VII. Following completion of the western sites, the remaining 13 ISG sites were grouted in stages.
The only schedule milestone for the project was the completion of field operations by the end of Fiscal Year 2010, September 30, 2010. This date was also significant because of the subsequent threat of freezing weather conditions, which had not been accounted for in the system design. The final schedule consideration was the soil vault, which was scheduled last for Rig #2 because of the increased drilling depth of 25 ft. The added drilling depth required attaching a 10-ft monitor extension. Section 126.96.36.199 describes routine daily operations and procedures associated with primary system components.
Figure 16. Site plan for in situ grouting at the Subsurface Disposal Area.
188.8.131.52 Daily Operations. Daily operations began with the morning pre-job briefing which covered the tasks to be carried out for that day. Following the pre-job briefing and prior to the start of production, each operator performed and documented a safety/operational readiness walkdown of each piece of equipment to verify operational readiness. This was performed with oversight from the superintendent and STR to ensure identified issues were resolved prior to start of operations. As discussed, daily operations were performed to the work order which was planned per STD-101 and associated HBI’s Operation and Maintenance (O&M) Plan, job safety analysis, and Drilling and Grouting Plan. Once STR and superintendent approval to start operations was granted, drilling and grouting operations began. Figure 17 shows the flowchart for grout delivery into the subsurface. Sections 184.108.40.206.1 through 220.127.116.11.6 discuss the steps in the O&M Plan to deliver grout.
Figure 17. Flowchart for grout delivery into the subsurface.
18.104.22.168.1 Grout Mixing—Grout was mixed using the batch plant. The silo was filled by first placing the super sack on a stand and replacing the factory string that closed the chute on the bottom with a zip tie. The sack was then lifted into place over the silo and the zip tie was cut, releasing the binder material into the silo. The binder material (dry grout mixture) was transferred from the silo into the mixing tub of the batch plant, and the appropriate amount of water was added to achieve the desired ratio of cement to water. Grout was mixed until it met specifications.
22.214.171.124.2 Drilling—The driller maneuvered the mast until the data logger indicated the bit position was within 0.2 ft of the preprogrammed ISG insertion point coordinates. The driller recorded the unique insertion location identifier (Column ID), and date on the HBI jet grout production log. He then visually confirmed the work area was clear and lowered the bit until it was even with the ground surface. Grout flow was then initiated under low pressure (trickle flow) supplied by the batch plant. After grout trickle flow was observed, drilling began using both percussive action and rotation at the driller’s discretion. The bit was inserted approximately 2 ft bgs after which the driller actuated the touch screen control in the cab of the drill rig to allow power to the high-pressure pump. He then contacted the pump operator via radio and instructed him to engage the pump for low-pressure grout injection. Drilling was advanced to the target depth of 17 ft bgs for waste trenches or 25 ft for the soil vault location, or until refusal was met, whichever came first. If refusal was encountered at a depth greater than 4 ft bgs or target depth was reached, high-pressure grouting began. If refusal was encountered at a depth less than 4 ft bgs, the location was abandoned and the rig was moved to the next insertion point. Refusal was defined as 29 seconds of vigorous drilling with less than 2 in. of penetration. The 30-second hold point was developed to ensure each insertion point was drilled to the maximum achievable depth.
126.96.36.199.3 Grouting—Upon achieving total depth, the drill rig operator communicated with the pump operator to initiate the high-pressure grouting system and initiated the automated DAS. Prior to initiating flow, the pump operator visually confirmed and communicated that the high-pressure safety area was clear and the protective shielding was installed around the high-pressure pump outlet. He then slowly brought the pump up to an operating pressure of 5,500 psi while observing pressures and flows. The driller then rotated the drill string for 30 seconds with no retraction to ensure grout flow to the nozzles after which he began drill string retraction. During this operation, the drill rig operator manually recorded grouting start and stop times and associated footages, total gallons delivered, and rate information from the DAS readout in the cab of the drill rig to complete the jet grout production log for the insertion location.
With the aid of the ground man and the CWI project engineer, the driller visually observed grout returns and the ground surface for any indication of heave or excessive returns. Drilling parameters were adjusted by the drill rig operator with an automated step function to control grout returns. Each rig was programmed with two discrete step functions that affected the rotational rate of the monitor. Grouting of insertion points was routinely started at a lower rotational speed (rpm), which slowed the retraction rate or step speed and, thus, delivered more grout per step. If grout returns were observed, the drill rig operator could activate the second step function, via a switch in the cab, increasing the rotational rate and, in turn, the step rate, thus reducing the amount of grout delivered per step. Step adjustments varied by rig and by ISG site because of differences in system hydraulics and waste heterogeneity. Operationally, step functions or settings were to be maintained within the following parameters, established for the project based on research and development for ISG conducted at the INL Site in simulated waste pits (see Section 3.1 of the Phase 2 Work Plan):
- Pull rate: 20–100 cm/minute (8–39 in./minute)
- Revolution per minute (rpm): 17–40
- Nominal step size: 2 in. while maintaining a minimum of 0.9 rotations per step
- Operating pressure: 345–517 bar (5,000–6,000 psi with a normal operating pressure of 5,500 psi).
During the grouting operations, pressures and flows were constantly observed. If excessive pressures or flows were observed, the driller or pump operator could activate a kill switch to immediately shut down the pump and communicate the action, after which the drill rig operator would actuate the touch screen control in the cab of the drill rig to cut power to the high-pressure pump. No such event occurred over the course of the project. Instances of anomalies in the data sets were observed over the course of the project and are discussed in Section 3.6.
To continue the operation, the drill string was retracted to 4 ft bgs where the pump operator was instructed to shut down the high-pressure pump and continue trickle flow using the batch plant
low-pressure pump. If the drill rig operator failed to instruct the pump operator to return the high-pressure pump to idle or if the command was not implemented when the drill bit reached the 4-ft depth, a safety feature automatically shut down the pump at 3.8 ft bgs. At this point, the mixing plant operator was instructed to discontinue trickle flow. Zero pressure was verified in the grout delivery system, drill string withdrawal was completed, and the rig was positioned over the next insertion point.
188.8.131.52.4 Moving Between Sites—When moving between sites, the drill string was allowed to drain into a grout returns basin while the drill rig operator verified zero pressure in the grout supply system. Power was cut to the high-pressure pump by actuating the touch screen control in the cab of the drill rig. The drill rig operator then engaged the hydraulic safety shutoff in the drill rig cab, actuating the green “safe to approach” beacon and informed the crew that there was zero pressure in the grout supply system. The drill rig operator then directed the ground man to detach the high-pressure grout hose from the drill rig slick line and cap both open ends of the grout delivery system. At this point, the system was flushed if the operational day was complete or if excessive downtime was anticipated. If a system flush was not required, the ground man and RadCon technicians entered the contamination area; RadCon technicians performed a radiological survey of the foot of the drill mast and performed spot decontamination, if necessary, and aided the ground man with the attachment of the drawstring sack containment over the deflection shield at the base of the drill mast. The rig was then moved under constant observation by the ground man and RadCon personnel.
HBI personnel re-staged the grout mixing plant, high-pressure pump skid, generator, and ancillary support hardware. Following removal of hosing and electrical leads, components were lifted from beneath by the all-terrain forklift and repositioned at the designated staging area. CWI construction forces relocated personnel comfort stations, shade and drinking water shelters, and RadCon supply cabinets during the move.
184.108.40.206.1 System Flush—During the project, system flush operations were performed using two of three approved operational approaches. The first, and most common approach, involved the removal of the nozzle and displacement of dilute grout to the grout containment and excess grout basins (see Figure 18). The second approach was implemented as an emergency measure and involved the injection of flush materials into the subsurface, outside of the waste zone, with the nozzle inserted in the monitor. Specific instances where this was implemented will be discussed in Section 3.6.
Under “normal circumstances,” flush operations consisted of the drill rig operator allowing grout remaining in the drill string to drain into the grout returns basin. After the draining was complete, zero pressure was verified in the system and power was cut to the high-pressure pump from the touch screen control in the cab of the drill rig. Once the mast was positioned to allow personnel access away from uncured grout returns, the drill rig operator engaged the hydraulic safety shutoff in the drill rig cab and directed the ground man to detach the high-pressure grout hose from the drill rig slick line and position and secure it to drain into the excess grout basin. The drill rig operator then removed the ignition key and provided it to the ground man to control while removing the nozzle. RadCon technicians and the ground man then entered the contamination area to survey or clean the monitor and nozzle surfaces for nozzle removal and subsequent flush operations. While these steps were taking place, the pump operator disconnected the low-pressure grout line from the low-pressure side of the high-pressure pump and connected it to the fresh water supply pump on the water tank. At this point, both the batch plant operator and the pump operator removed and cleaned in-line screens to minimize occurrences of nozzle plugging.
To commence flushing of the high-pressure pump and high-pressure hose, the pump operator was instructed to start the high-pressure pump, initiate water flushing using the fresh water supply pump, and run water through the high-pressure pump and high-pressure hose, while allowing the pump pistons to stroke, to displace grout into the excess grout basin. Once fresh water was observed flowing from the high-pressure hose, flow was discontinued and the hose was repositioned to complete this segment of the operation by discharging fresh water into the local drainage system. To complete the flush of the rig and monitor, the drill rig operator first ensured personnel had exited the grout returns basin within the posted radiation contamination area. The ground man then reconnected the high-pressure grout line to the drill rig slick line. Upon reconnecting, the drill rig operator instructed the high-pressure pump operator to initiate water flushing from the fresh water supply pump, through the high-pressure pump and out through the nozzle port under low pressure and flow. At the same time, the pump operator removed the protective shielding around the outlet of the pump and actuated the manual pressure relief valve on the front of the high-pressure pump to thoroughly flush it with clean water and to flush the grout relief deflection box on the back of the high-pressure pump. Once clean water was observed flowing from the nozzle port, the drill rig operator engaged the hydraulic safety shutoff in the drill rig cab, shut off the drill rig, removed the ignition key, and provided the key to the ground man to control while the nozzle was replaced in the monitor and the protective shielding replaced around the outlet of the pump.
Figure 18. System flush process.
To protect the safety of personnel and prevent damage to drilling components in a lightning take cover occurrence, the option to flush material into a non-waste-bearing subsurface location was
exercised. In each instance, project technical support personnel identified a location outside the treatment site to conduct the operation. Once the monitor was in position, it was drilled to total depth. Water was then pumped via the high-pressure pump (pressure range between 500 and 1,500 psig) through the system and out the monitor as the monitor was raised and lowered and rotated to dissipate the flush water.
Following displacement of the grout with fresh water, the drill rig operator ensured the high-pressure pump was deenergized, the drill string was raised to the surface, and clean water was observed exiting the nozzle indicating the system was clean. In each instance, following the emergency situation, the resultant penetration was plugged by tremieing grout product to the surface over its entire length. Prior to the drill rig and mast flush operation, the high-pressure pump and supply hosing were disconnected from the rig and flushed separately into the excess grout basin by the crew to minimize the amount of material being directed through the nozzle port.
In conjunction with both system flush operations, the batch plant operator washed the inside and outside surfaces of the batch plant with minimal fresh water. Displaced dilute grout and water from the mixing plant and residual flow through the high-pressure pump and supply lines were directed onto the adjacent ground surfaces or into local drainage. Following mobilization of the support equipment, remaining residual material was scraped off the surface and disposed of.
220.127.116.11.1 End of Shift—Following flush operations, HBI personnel proceeded to download data acquisition files from drill rig, place the equipment in a safe configuration, shut down equipment, and put away tools.
1.1 Deviations from the Phase 2 Work Plan
The Phase 2 Work Plan (DOE-ID 2010) acknowledged that modifications could be required during implementation of ISG and outlined a flexible process to manage change (see Section 1.4 of the Work Plan). That process was invoked several times. None of the changes affected location-specific remedial designs, and each site was treated in accordance with its remedial design without deviating from the planned treatment footprint and number of grout insertions. Neither was any change so significant that it warranted revision of the Work Plan. Agency representatives concurred with these modifications in conference calls or site visits, as allowed by the Work Plan. The Agencies formalized their agreement through review of this interim completion report. As required, this report documents the changes.
One change to the waste management strategy was identified and discussed among the Agencies during a conference call (March 1, 2010) before ISG mobilized. As agreed, excess clean grout from ISG daily operations was disposed of in grout returns basins within the SDA. This approach is a minor change from the original plan to dispose of clean excess grout outside of the SDA (Table 5-1 of the Phase 2 Work Plan).
The drill system design was slightly modified after a nozzle was damaged during the MSA at the cold test pit. As discussed with the Agencies (June 7, 2010), investigation concluded the nozzle orientation, which was 15 degrees down from horizontal, caused the damage. Horizontal nozzle orientation was implemented to prevent further problems. This decision constituted a change to Item 19 in Section 18.104.22.168 of the Phase 2 Work Plan.
A field decision, defined as “…real-time refinements to ISG-site-specific location designs or to ISG operating parameters” (Section 4.4.3, DOE-ID 2010) was adopted after ISG operations began. After careful review of operating data, the Agencies concluded during a conference call (August 12, 2010) that exceeding the upper-bound retraction rate was an acceptable condition arising from efforts to minimize grout returns in keeping with the ISG safety basis. ISG operations were to remain within the operating parameters specified in Section 22.214.171.124 of the Work Plan to the maximum extent practicable; however, deviations—such as to a higher retraction rate (Item 20b in the Work Plan)—were allowable to reduce grout returns. Such changes could not jeopardize the overall ISG performance objective (i.e., at least 80% of the maximum potential volume for the ISG site). (Note: ISG exceeded the performance objective at each location.)
- 3. CHRONOLOGY OF EVENTS
The OU 7-13/14 ISG Project was separated into specific work elements for implementation of the Phase 2 remedial action. The chronology of these elements form the basis for detailed discussion of the work presented in Sections 3.1 through 3.9 as follows:
- Section 3.1—Selecting a Vendor
- Section 3.2—Offsite Demonstration
- Section 3.3—Site Preparation
- Section 3.4—Management Self-Assessment and Authorization to Deploy
- Section 3.5—Mobilization
- Section 3.6—Remedial Action
- Section 3.7—Pre-Final Inspection
- Section 3.8—Phase 2 Close-Out
- Section 3.9—Post-Construction Operations and Maintenance.
3.1 Selecting a Vendor
The procurement strategy for ISG was modeled after the successful beryllium grouting project executed in the SDA in 2004 (Lopez et al. 2005). The project was performed as a construction job with a subcontractor drilling and grouting and ICP providing support functions.
A pre-solicitation notice for vendors interested in the job was published on the Federal Business Opportunities Web site April 29, 2009. Interested parties were requested to respond no later than May 22, 2009, after which time a directed request for proposal process was conducted. The request package included the Statement of Work, Special Conditions, the Construction Specification, and General Provisions. On October 1, 2009, the request for proposal was issued on a competitive basis to 12 potential vendors with a proposal due date of November 2, 2009. A pre-bid conference and tour was held at the RWMC October 13, 2009. Sixteen subcontractor representatives attended the conference, which included presentations by contractor representatives on safety, quality, RadCon, labor relations,f and construction. Two addenda to the request for proposal were issued before the proposal due date and five proposals were subsequently received.
A team of four project personnel evaluated proposals based on an Evaluation Plan (ICP 2009) developed specifically for the project. After the proposals were evaluated, a third addendum to the request for proposal was issued clarifying bid quantities and providing questions and comments specific to each vendor. All five vendors responded. The technical evaluation was performed without knowledge of bid price and all proposals were ranked. After the technical evaluation was complete, price was evaluated and the best overall value to the government was determined. On December 10, 2009, the subcontract to execute construction services for the Phase 2 OU 7-13/14 ISG Project was awarded to HBI.
HBI is a subsidiary of the Keller Group, a large, worldwide independent ground engineering specialist. HBI is the largest of the Keller Group’s geotechnical companies and one of the prominent geotechnical contractors in North America.
3.1 Offsite Demonstration
In accordance with the project specification (SPC-1162), HBI was required to conduct a CC/SO test with the drilling and grouting system developed for use at the INL Site. Testing was conducted to a CC/SO Test Plan (VDR-300568), which was managed through the CWI vendor data system. HBI was required to conduct these tests using procedures developed for reference in INL Site work documentation. The purposes of this test were for HBI to (a) demonstrate equipment configuration and operability consistent with the approved system design and (b) develop and demonstrate the ability to perform the grouting operations to the requirements of the Phase 2 Work Plan (DOE-ID 2010).
The demonstration consisted of the following test elements: an operational system pressure test, a grout operations test, and grout placement qualification. The demonstration mirrored, to the extent possible, the grout operations to be performed at the SDA. After the demonstration, an HBI report documented the demonstration and listed revisions to the equipment configuration or system operation (VDR-306854). On April 14, 2010, the offsite demonstration was conducted at the HBI facility in Santa Paula, CA.
3.2.1 Test Pit Construction
The offsite demonstration simulated waste pit was constructed to meet the specifications of the CWI-supplied engineering design file (EDF-9512). The Engineering Design File provided direction for preparing surrogate containerized buried waste forms and subsequent placement of surrogate waste in the test pit; this simulated project-specific buried waste sites located within the SDA. The pit design allowed for demonstration of all test objectives. The ICP Waste Information and Location Database provided the design basis for surrogate waste formulation, container type, and associated loading ratios.
Buried waste container types consisted of 2- × 2- × 2-ft cardboard boxes, 4- × 4- × 2-ft plywood boxes, and 55-gal metal drums lined with appropriately sized 4-mil polyethylene bags. Additional container types included 5-gal steel drums or canisters and 1-gal paint cans. Each container was loaded with a specific surrogate waste type. Surrogate waste types included combustible (e.g., paper, wood, asphalt, and plastic) and noncombustible debris (e.g., assorted metal scrap and glass) and surrogate sludge containing kitty litter. The container was packed with equal amounts of each surrogate waste (i.e., manually compressed material) until full. Containers were taped closed and/or covered and sealed. Table 5 contains information on individual containers and the associated surrogate waste types placed in each. Note that not all surrogate waste types were placed in all containers.
The test pit dimensions were 4.5 ft wide × 7 ft long × 13 ft deep. The bottom of the pit was lined with concrete riprap and steel to simulate absolute refusal. Placed above the base were four 2-ft-thick surrogate waste form layers separated by soil and loose debris, consisting of scrap metal, combustibles, gravel, and asphalt. The total thickness of the surrogate waste seam was 9 ft. Waste forms were strategically placed into the excavation to simulate a random dump while maintaining a record of placement for later reference. Figure 19 shows a schematic of the CC/SO test pit construction.
The placement of surrogate waste followed the design identifying the location of each surrogate waste form placed in the pit. Figures 20 through 23 show the distribution of the surrogate waste containers in the CC/SO test pit at various depths. Layouts in the figures are shown in four 2-ft layers, from the bottom up. The pit was capped with a 1-ft layer of overburden soil, 1-ft layer of hardpan soil, and another 1-ft layer of overburden soil. The hardpan soil was clay material that was compacted to represent the hardpan layer within the SDA. Surrounding the test pit was a 1-ft berm constructed to represent the grout returns basin.
Figure 19. Schematic of component checkout/system operational test pit construction.
Figure 20. Layout of Layer 1 of the component checkout/system operational test pit (0–2 ft from bottom of the pit).
Figure 21. Layout of Layer 2 of the component checkout/system operational test pit (2.3–4.3 ft from bottom of the pit)
Figure 22. Layout of Layer 3 of the component checkout/system operational test pit (4.6–6.6 ft from bottom of the pit).
Figure 23. Layout of Layer 4 of the component checkout/system operational test pit (7.9–8.9 ft from bottom of the pit).
3.2.1 Test Results
Testing was performed to a CC/SO Test Plan (VDR-300568) which was developed by HBI and managed through the CWI vendor data system. Testing included a full mockup comprising simulated SDA waste, RadCon and safety controls, and conduct of operations. These tests let the CWI project team verify functionality of all aspects of the system (e.g., safety systems, data acquisition, positioning, rotary percussion drilling), observe the adequacy of the HBI’s operating procedures and their interface with CWI STD-101 work documents, and observe the resultant grouted simulated waste zone.
At this time, the CWI project team trained HBI personnel to standard RadCon and INL Site work protocols. Members of the CWI field team, consisting of engineering, safety/IH, RadCon, operations, quality, and the nuclear facility manager, were present to gain experience with the ISG system and operating procedures. CC/SO testing was conducted at the HBI’s facility located in Santa Paula, CA, on April 14, 2010, and was also attended by DOE and DEQ representatives. The following sections discuss results by test element.
126.96.36.199 Operational System Pressure Test. The first test element consisted of the operational system pressure test, in which each component in the high-pressure system was brought up to operational pressure to verify its functionality, including the redundant pressure relief features. This was conducted at a site adjacent to the test pit. During the check, components of the high-pressure system were visually inspected for proper pressure ratings, leaks, and proper operation when at pressure. During testing of the mechanical pressure relief device, the maximum rated pressure was also tested. After the inspection was completed, the system component check log was completed and approved by the HBI inspecting technician.
188.8.131.52 Grout Operations Test. The second test element consisted of the grout operations test. HBI demonstrated and documented the readiness of the grouting operation. The demonstration simulated, to the extent possible, grouting operations to be performed in the SDA. To verify readiness, HBI drilled and grouted 10 test holes in the simulated test pit. The 10 holes were selected so that all waste forms would be drilled and then grouted. The test holes were laid out in a triangular-pitch matrix, 20 in. on center, and labeled TH1, TH2, TH3, TH6, TH7, TH10, TH11, TH12, TH15, and TH16. A pre-job safety briefing was conducted, involving both HBI and CWI personnel, and daily equipment checks were performed prior to the start of operations. Upon completing these tasks, HBI drilled and grouted the
10 test holes. In doing so, HBI verified that the equipment was capable of grouting within the parameters found in the Drilling and Grouting Plan by implementing procedures in the O&M Plan. The following eight functions composing the grouting operation were successfully demonstrated:
- Safety systems operate as designed.
- Grout batching and maintaining grout specifications.
- Pump capacity is capable of operating at planned injection parameters.
- Drill rig is capable of drilling to the required depths and injecting at the planned parameters.
- Contamination control measures are acceptable.
- Procedures are understandable.
- DAS provided required data.
- Hand logs were filled out correctly (i.e., drill log and grout specific gravity log).
As part of the demonstration, HBI also was required to implement support functions from the O&M Plan for verification and testing and to provide practice to their crew. The following sections summarize these actions.
184.108.40.206.1 Safety System Test—Throughout the test, operability checks were
performed on all safety features. Safety features of the high-pressure system are discussed in Section 2.3 of this report. The following list comprises the system features and practices that were documented during the grouting of TH1:
- Hydraulic lockout in excavator cab
- High-pressure pump shutoff in excavator cab
- Anti-rotation lockout on excavator chassis when in drill mode
- Redundant overpressure shutoff and relief
- Automatic pump shutoff at 3.8 ft bgs
- Verified radio assignments and communication protocol
- Verified equipment travel routes, hand signals, and equipment placement.
220.127.116.11.2 Pressure Relief System—During the grouting of TH1, the following component pressure relief functions were verified for the high-pressure pump:
- Electronic overpressurization safety switch
- Manual pressure relief valve
- Mechanical overpressurization device
- Excavator cab emergency shutdown switch
- Pump emergency shutdown switch.
During the grouting of TH1, the monitor was withdrawn to 5 ft bgs. Upon reaching this depth, the electronic overpressure protection device was successfully tested. The DAS data indicated that the pump shut down upon reaching 6,100 psi, slightly high. To test the mechanical device, the electronic pressure relief setting was increased beyond the shear pin setting of 7,100 ± 300 psi and the system was again pressurized. The mechanical device ruptured at approximately 7,250 psi, verifying its function and system integrity at its maximum rated pressure. While grouting TH3, the emergency pump shutdown switch located in the excavator cab was tested. After allowing the monitor to withdraw to 4 ft bgs, the driller cut power to the high-pressure pump with the in-cab shutdown button. To verify the manual pressure relief valve was operating properly, grout was pumped through the high-pressure pump at low pressure and the valve was opened. Upon opening the valve, a visual inspection verified grout was flowing through the relief valve and system pressure was negligible.
18.104.22.168.3 Grouting Pressure Test—The components of the high-pressure system were required to operate consistently at a system pressure of 5,500 psi. This was verified while grouting TH2. During the grouting of TH2, pressures and flow were recorded for 5 minutes. For this duration, the pressure readings were consistently 5,500 psi and flow was 15.1 gpm. Grout was being injected through a 2.4-mm nozzle and had an average specific gravity of 1.55. After completing the 5-minute time interval, the system pressure test log was approved and signed by the HBI's inspecting personnel.
22.214.171.124.4 Step Function—During the grouting of TH12, the alternate step function, “Step 2,” was successfully demonstrated. Drilling controls were capable of two pre-programmed speeds or steps. An increased pull rate and rotation rate was used to minimize grout returns to the surface. Grout injection was initiated at a lower speed and was then increased by the drill rig operator, on-the-fly, by actuating the step function.
126.96.36.199.5 Contamination Contro l- Throughout the test, the following contamination control measures were practiced and evaluated:
- Equipment and personnel positioning and travel relative to simulated RadCon barriers
- Monitor fixative spray
- Monitor wipers
- Contamination control plate and base assembly.
188.8.131.52.6 Data Acquisition and Logkeeping- During the demons tration, HBI demonstrated the fonctionality of the DAS and manually recorded drilling and grout specific gravity logs. DAS data were recorded and submitted in presentation fonn upon completion of the test. Table 6 presents a summary of DAS output parameters. Manual drilling logs were reviewed to verify they were comparable with the automated system.
184.108.40.206.1 System Flus h- Fo llowing grouting operations , CWT project management and RadCon representatives detennined that steps associated with flushing the drill rig and monitor should be conducted separate from the drilling and grouting test to aJlow personnel to focus on RadCon procedmes. Flush and cleanup operations were evaluated on the grout supply lines and primary and ancillary system components according to steps in the O&M Plan and were detennined to be successful. The system was clean from the previous day's flush and zero energy was verified prior to the mockup . A simulated contamination area was roped and posted in preparation for the test. Operational flush equipment and the rig were placed in a safe configuration with the drill rig mast supported by cribbing. Personnel entering the simulated contamination area were required to don personal protective equipment at direction of CWT RadCon representatives. Steps in the O&M Plan were implemented to verify operability of the drill rig flush . Decontamination of the monitor surface was practiced and the contamination control sleeving was successfully secured. The required amount of sleeving was cut away to allow removal of the nozzle. The drill mast was positioned within the waste container and flush completed. Figures 24 through 28 show various stages of the “containerized flush operation,” including nozzle decontamination, placement of the monitor sleeve, positioning of the monitor over the flush tank, flush water exiting the nozzle port, and site view of the operation.
Though the operation was determined to be effective, ICP Safety and RadCon representatives observed several steps that were cumbersome or presented safety concerns and presented mitigations to HBI for incorporation into their operating procedures. However, an operational refinement was identified involving flushing grout to grout returns and excess grout basins. Clean excess flush water was discharged to SDA ditches. Section 220.127.116.11 discusses adoption of this alternative in more detail.
18.104.22.168.2 Nozzle Change-Out—During the grouting demonstration, occasional plugging required changing a nozzle. Impurities in the neat grout caused the nozzle plugging. Assessments of the in-line filters and material behind the plugged nozzle identified plastic webbing fragments introduced into the mixture from opening the super sacks directly over the binder silo (see Figure 29). Solidified binder fragments also were observed, which originated from staged super sacks exposed to heavy rains. The sacks were not waterproof; thus, areas of the binder material became hydrated, were then cured, and subsequently were introduced into the grout mix when the affected sack was loaded into the silo.
Figure 24. Nozzle decontamination.
Figure 25. Placement of the monitor sleeve
Figure 26. Positioning the monitor over the flush tank.
Figure 27. Flush water exiting the nozzle port.
Figure 28. Site view of the containerized flush operation.
Figure 29. Low-pressure grout system filters plugged with super sack webbing material.
Nozzle change-out also was required in separate instances because of pressure losses from galling of nozzle threads. Abnormal wearing of the nozzle and adjoining monitor threads, observed in the 15-degree nozzle port configuration, was caused by an extension of the nozzle insert into the annulus of the monitor. The extension interrupted grout flow and abraded the nozzle threads.
During grout operations tests, nozzles were changed according to procedure without imposing radiological protection measures. A thorough evaluation of the spot decontamination and accompanying nozzle change-out procedure, with radiological measures, was conducted as part of the separate system flush evaluation and determined to be successful.
22.214.171.124 Grout Placement Qualification. The third test element consisted of grout placement qualification. HBI provided operational data and drilling log information so the project team could evaluate the post-grout-injection qualification process and demonstrate the effectiveness of the successful placement of grout. In addition to the data provided by the DAS and logs, the grout qualification required a portion of the test pit to be exposed. This requirement called for the top 4 ft of the test pit to be removed, exposing the top portion of the grout columns. Along with the top 4 ft being removed, the front edge of the grouted area was exposed and inspected. The inspection verified that, given the grouting parameters, a competent monolith was created. Figures 30 through 34 show the process of exposing the monolith, exposed sections of the monolith, a single grout column measured at nominally 26 in. in diameter, and samples of treated debris taken from the monolith.
3.2.2 Test Configuration Certification
After completion of the offsite demonstration, HBI was required to submit a report documenting the demonstration and listing needed revisions to the equipment configuration and system operating procedures. These changes were documented and tracked. When equipment was delivered at the INL Site, HBI was required to provided a Test Configuration Certification (VDR-307812) documenting that the final operating procedures and equipment test configuration were not modified, except as documented and approved by the CWI project engineer. Table 7 contains system design and operational changes that were implemented during and after the offsite demonstration.
HBI drilled and grouted 10 test holes for the offsite demonstration test. This test demonstrated all procedures addressed in the Drilling and Grouting and O&M Plans, from the pre-job briefing to clean-out. HBI pumped a total of 1,592 gal of grout and created a competent grouted structure that encapsulated the surrogate waste and associated soil in the test pit.
Some issues were noted during the test. The containerized equipment flush operation was problematic. DOE, CWI, and DEQ representatives, present for the test, agreed that observed potential safety issues outweighed advantages of transferring flush water into containers outside the contamination area. Post-testing conversations involving Agency and CWI representatives concluded with a decision to flush water directly to the ground surface (see Section 126.96.36.199). CWI and DOE representatives discussed lessons learned, observations, and potential corrective actions with the HBI operations crew and technical staff. The test report recorded primary modifications to the equipment and procedures. Comprehensive operational, design, and hardware modifications were documented and approved through submittal of
the Test Configuration Certification (VDR-307812) prior to mobilization to the INL Site. The MSA (see Section 3.4) verified implementation of such modifications before start of construction on the INL Site.
Tests showed that the equipment, procedures, and personnel performed as planned and ICP judged the offsite test successful.
Figure 30. The process of exposing the monolith in the simulated test pit at Hayward Baker’s facility in Santa Paula, CA.
Figure 31. The process of exposing the test monolith.
Figure 32. Exposed top layer and front cross section of the test monolith.
Figure 33. A single grout column measured at nominally 26 in. in diameter.
Figure 34. Samples of treated debris taken from the monolith.
3.3 Site Preparation
Site preparation involved work performed in advance of subcontractor mobilization to facilitate construction at Cold Test Pit-South and ISG sites in the SDA. Construction work was performed in accordance with the approved project-specific health and safety plan, ICP work control documents, and Phase 2 Work Plan (DOE-ID 2010).
3.3.1 Cold Test Pit-South
HBI’s onsite demonstration at the Cold Test Pit-South (see Figure 35) supported the MSA to show that HBI and CWI personnel were ready for operations and to demonstrate acceptable proficiency of the jet-grouting design and operational procedures. The test pit was constructed in 1988 to provide a cold nonradioactive/nonhazardous test bed to conduct treatment and retrieval technology demonstrations. A series of test cells were constructed and filled with simulated waste and backfilled in the same manner in which RWMC waste was disposed of between 1953 and 1970 (BWP-ISV-009). Zone 2, a stacked drum region of the test pit, was selected for the demonstration. The site was grubbed and backfilled to provide a stable, level working surface. Areas for equipment unloading and parking were identified and the vegetation removed. Barriers and postings were improved and replaced around the perimeter of the test pit with current project information. A wide perimeter around the simulated test pit was fenced and posted as a construction barrier, and caution and warning zones were marked for the ISG operation.
The site was surveyed using a Leica System 1200 global positioning system and marked. A grout returns basin was excavated to support testing operations for both HBI Rig #1 and Rig #2. Rebar was driven 2 ft into the ground at the corners of the ISG site boundary. Aluminum survey caps, slightly elevated above the ground surface, were placed on top of the rebar. Once all of the survey caps were installed, as-built coordinates were collected. These point data defined the ISG sites on the ground surface and were used to generate an as-built geographic information system data layer for siting insertion points. CWI provided HBI with coordinates for each insertion point location within the test pit so locations could be preprogrammed into their positioning system and DAS database (see EDF-9531). A significant number of points were laid out to provide HBI an opportunity to test their hardware to the extent necessary. Site diagrams and coordinates for each insertion point are contained in Appendix A.
3.3.2 Subsurface Disposal Area
Site preparation within the SDA included establishment of the ISG sites, construction of the project infrastructure, and coordination of operational activities with RWMC facility management and ongoing projects within the SDA.
188.8.131.52 ISG Sites and Insertion Points. The Phase 2 Work Plan (DOE-ID 2010) documents the process by which the optimized ISG location designs, with definitive buffer areas, were established. Through this process, treatment areas were reduced while increasing the total curies of releasable Tc-99 and I-129 that were treated. Grouting the injection pattern (e.g., 20-in. center-to-center) at each trench location buffered each site by 3.5 ft on the ends and by 2 ft on the sides, equating to two grout columns of buffer on each end and one grout column on each side beyond the actual trench width. The soil vault location was ringed by a grout wall approximately 2 ft thick. Prior to HBI mobilization, coordinates for the 21 ISG sites were surveyed using a Leica System 1200 global positioning system with horizontal accuracy of ±1/4 in. Rebar was driven 2 ft into the ground at the corners and intermediate points along the ISG site boundaries. Aluminum survey caps, slightly elevated above the ground surface, were placed on top of the rebar (Figure 36). Once all of the survey caps were installed, as-built coordinates were collected and the survey caps were stamped with unique codes. These point data defined the ISG sites on the ground surface and were used to generate an as-built geographic information system data layer for siting insertion points.
Figure 35. Simulated in situ grouting site at the Cold Test Pit-South.
A trigonometry calculator was used to calculate the 20-in. triangular-pitch matrix coordinate offsets where x,y for A = (0, 0), B = (0, 20), and C = (10, 17.3). These calculations were used in Excel to generate a template of insertion points that was wider and longer than the largest ISG site. Using ArcMap geographic information system software (ArcGIS 2008), this template was copied, moved, and rotated to fit each individual ISG site established by the as-built geographic information system data layer. Excess insertion points that fell outside of each ISG site were deleted. Each insertion point was documented with the ISG site name, the insertion point name (i.e., insertion waypoint ID), and easting/northing coordinates. Easting/northing coordinates were calculated automatically by the ArcMap geographic information system software. Appendix B includes site diagrams and coordinates for each corner and intermediate points along the ISG site boundaries and insertion point coordinates and detailed site diagrams for each site.
Figure 36. In situ grouting site boundary aluminum survey cap.
184.108.40.206 SDA Infrastructure. To support grouting operations, a project administrative and laydown area was constructed comprising the following actions: siting and setting up temporary office trailers, parking areas, equipment and material laydown areas, and a temporary CERCLA waste storage area.
ISG Project personnel worked with facility representatives to establish interfaces for road outages, traffic flow, and shipment patterns and schedules; ARP IV project engineers to establish ISG application scheduling and final elevation requirements in ARP footprint areas; SDA system engineers to place new abovegrade fire protection system; and other activities (e.g., vapor vacuum extraction and environmental monitoring) to minimize impacts to ongoing operations. Subsurface investigations and review of SDA critical utility drawings indicated that ISG operations would not affect any utilities. The nuclear facility manager and Site Support Services enforced standard precautions associated with springtime subsidence in the SDA through mid-June.
CWI surveyed and marked each ISG site coordinate before HBI mobilized. CWI supplied HBI with coordinates for each of the 2,168 insertion points in EDF-9531 so they could preprogram locations into their positioning system and DAS.
Setup involved establishing operational, RadCon, and OSHA/HAZWOPER boundaries and support facilities at ISG application sites. Boundaries were installed and posted in compliance with the project-specific health and safety plan (PLN-3412) and radiological work permit (No. 31010780). An expansive access-control boundary was established around the perimeter of each work area to encompass the ISG operation. Boundaries normally included more than one ISG site and were posted with signs indentifying the boundary as a “Construction Area,” as a “CERCLA/OSHA HAZWOPER Controlled Area,” and for authorized personnel entry only and included a caution for intermittent high noise. A separate internal boundary was established by safety and IH professionals that encompassed the drill rig, mixing and high-pressure pump facilities, and the entire length of the high-pressure grout supply hose.
Postings consisted of caution “high noise area,” hearing protection required, and danger “high pressure system area.” The geometry of this boundary varied from site to site based on equipment positioning.
Setup also included implementation of the HBI’s ICP-approved O&M Plan (VDR-296417) for managing grout returns and system flush operations. Grout returns basins were developed by excavating the upper 1 ft of overburden, extending nominally 3 ft beyond the outer row of insertion points. Separate basins were excavated in the vicinity of the each ISG site, outside of the designated treatment area, to receive excess grout from the batch plant and pump. Boundaries were posted around these facilities by CWI RadCon, safety, and IH professionals to protect personnel and equipment. A continuous caution boundary was established around the outer perimeter of the grout returns basin. This boundary was posted as a “radiological buffer area” and contained controlled ingress and egress paths, personal protective equipment donning and doffing areas, and a step-off pad for radiation contamination control. RadCon screening tools and supply cabinets were staged just outside the radiological buffer area. The access point was posted as a “CERCLA/HAZWOPER Exclusion Zone.” Located inside of this barrier, nominally following the perimeter of the grout returns basin, was an enclosed caution “Contamination Area” boundary. Figure 37 depicts the relative configuration of the controlled zones with associated postings.
Figure 37. Relative configuration of controlled zones with associated postings.
3.1 Management Self-Assessment and Authorization to Deploy
A hazard assessment document (HAD-460) was prepared to implement a graded approach to nuclear safety management for the project. Waste disposal areas at the RWMC are classified as a Hazard Category 2 nuclear facility. The ISG Project was segmented for hazard categorization from the rest of the RWMC and it was determined to be a less than Hazard Category 3 activity. As such, an MSA was not required but one was performed as a best management practice. This MSA was performed following established procedures for startup of nuclear facilities. An MSA Plan (PLN-3456) was prepared to establish the scope, define the approach and process, and define the prerequisites for the MSA.
The MSA addressed the readiness of personnel, equipment, and work control documents for drilling and grouting operations. The following operational activities were evaluated through observations of evolutions, walkthroughs, interviews, and review of documentation:
- ISG operations, setup, mobilization
- Grout mixing
- Grout delivery
- Cleanup of systems.
HBI began setup of equipment in Cold Test Pit-South on May 10, 2010. The next 2 weeks were devoted to ensuring the equipment met requirements, the operators were fully trained, work control documentation was complete, and practice evolutions were performed for all operations. Figure 38 shows equipment setup in Cold Test Pit-South prior to practice operations.
The MSA started May 24, 2010, and the MSA report was issued June 3, 2010. The MSA evolutions included drilling and grouting two separate locations, equipment clean-out, and removal of the drill mast from the contamination area to simulate equipment relocation. Additionally, a practice fire drill was performed with fire equipment response by the INL Fire Department. Fifty locations were historically mapped for potential use in Cold Test Pit-South, but only six locations were actually used during testing and the MSA. Figure 39 shows the six locations in Cold Test Pit-South that were drilled and grouted. See Appendix A for location coordinates.
Based on successful operational evolutions, HBI was given notice to proceed into the SDA for setup on May 27, 2010. The MSA team identified seven pre-start findings and no post-start findings. Corrective actions were immediately identified and implemented. Work control documents were updated, tailgate training was provided to the operations crew, and ICP authorized HBI to begin operations. Lessons learned from the MSA are provided in Section 6.
HBI mobilized to the INL Site from May 10 through May 17, 2010. They moved equipment to the Cold Test Pit-South in preparation for the MSA and onsite testing and completed their personnel training. The RWMC nuclear facility manager granted work authorization and Rig #1 was moved onsite. Upon arrival at the INL Site, all HBI equipment underwent baseline surveys by RWMC RadCon personnel (see Section 3.6). The construction STR and the project field team leader oversaw mobilization. Assorted HBI equipment was unloaded from several flatbed trucks using the HBI all-terrain forklift and a leased mobile crane, supported by ICP construction forces with use of an ICP heavy-duty all-terrain forklift (Big Red).
After equipment was unloaded and partially assembled, it was positioned on the Cold Test Pit-South simulated test pit for final assembly. Receipt inspections performed by ICP quality assurance staff identified several nonconformance issues primarily associated with the electrical generator and power feed to the high-pressure pump provided to HBI from a local vendor. ICP construction electricians and RWMC electrical engineering staff contributed to the resolution of these issues by recommending an acceptable configuration. Following installation of the system, a management walkdown of the facilities was performed by the HBI superintendent, the STR, and RWMC safety and quality assurance professionals to ensure operational readiness.
Figure 38. Rig #1 setup in Cold Test Pit-South for the management self-assessment.
In conjunction with equipment mobilization efforts, HBI personnel received pre-scheduled site-specific training through the ICP training organization. Training for workers was tracked on qualified watch lists that were maintained for the project.
In preparation for mobilization into the SDA and hot operations, the project conducted an MSA from May 24 through June 3, 2010 (see Section 3.4). The RWMC nuclear facility manager authorized mobilization to the SDA following successful completion of the MSA.
Figure 39. Six locations in Cold Test Pit-South that were grouted during the management self-assessment.
Rig #1 mobilized into the SDA between May 26 and June 3, 2010, under oversight by the STR and the project field team leader. All HBI equipment was moved into the SDA through the south gate of the RWMC. Mobile equipment was tracked onto the SDA and staged in operational configuration on ISG Site T49A. Support systems were staged using the HBI all-terrain forklift. Following placement, ICP electricians and support staff installed required grounding and oversaw connection of equipment power leads. HBI support trailers previously were staged at the ISG laydown area, and bulk binder materials were placed near the first ISG site, T49A.
At Rig #1, following installation of the system, the HBI superintendent, the STR, and RWMC safety and quality assurance professionals walked down the facilities to ensure operational readiness.
Rig #2 mobilized between June 9 and June 14, 2010, following a similar process. Rig #2 was assembled at Cold Test Pit-South. Required pressure verification testing was performed on June 15, 2010, under RadCon, Safety/IH, quality assurance, project engineering staff, and facility representative oversight. Following verification of operational readiness and authorization by the RWMC nuclear facility manager, HBI Rig #2 mobilized to the SDA via the south gate and was staged over ISG Site T45B.
At Rig #2, following installation of the system supporting Rig #2, the HBI superintendent, the STR, and RWMC safety and quality assurance professionals walked down the facilities to ensure operational readiness.
3.6 Remedial Action
ISG commenced in the SDA on June 7, 2010, and was completed on August 25, 2010, with a total of 50 days of ISG operations. Treatment is complete at the 21 specified locations, in accordance with the Phase 2 Work Plan (DOE-ID 2010) as implemented through the “Drilling and Grouting Plan for Operable Unit 7-13/14 In Situ Grouting” (VDR-291709).
In accordance with the project specification (SPC-1162), HBI furnished all labor, material, equipment, tools, documentation, and supplies to test and perform the ISG operations using a jet-grouting process with a single-component, cement-based grout. Field operations consisted of site preparation; a design verification phase, including offsite and onsite testing; and a production phase, comprising ISG application, close-out, and demobilization activities. Operations were completed ahead of schedule and under budget with a total of approximately 20,300 man-hours (ICP 14,000; HBI 5,650; and 650 for oversight) and with no first-aid incidents, recordable injuries, lost time accidents, or radiological issues. The production phase began with one jet grout system in operation, with the second system commencing operations on June 18, 2010. In total, 677 tons of cement/slag, yielding 216,165 gal (1,070.3 yd3) of grout was pumped into the subsurface.
Table 8 contains project schedule information and a performance objective summary showing that ISG at each of the 21 locations exceeded 80% of the maximum potential volume, as required. Table 9 contains specific information for each ISG site. The table is organized chronologically by start date.
ISG site information is organized by “Site-Specific Information,” which contains a summary of RadCon and field team leader log information (e.g., routine or anomalous radiological survey data and responses, rig positioning, re-entries into insertion points for grout application); and “Operations and Maintenance,” which highlights impacts to grouting operations (e.g., maintenance activities, weather delays, and operational refinements).
3.6.1 Impacts to Grouting Operations
Based on lessons learned from previous ISG treatability studies, ICP communicated issues inherent to ISG operations to HBI. At the direction of ICP technical project personnel, HBI developed mitigations that were compatible with system hardware and incorporated them into their O&M Plan as “contingencies,” some of which were implemented during the project. The following paragraphs discuss these contingency measures and other mitigations to reduce operational impacts.
220.127.116.11 System Plugging. The most significant impact to ISG operations was the questionable quality of the binder material. Because of the small nozzle size selected for the project it was essential that the binder material be clean and free of impurities. Early in the project, between June 8 and June 17, 2010, HBI experienced mechanical problems with their system as a result of coarse sand discovered in the binder material. To mitigate this problem, HBI returned binder to their supplier and enforced quality assurance procedures for mixing the raw product. In addition, two additional filtration screens (for a total of three) were introduced into the system in advance of the high-pressure pump. The screens prevented impurities in the material from increasing wear on components of the high-pressure pump and prevented plugging the nozzle. Though the screens reduced wear on components of the high-pressure pump, the maintenance required for the pumps was more frequent than originally planned.
18.104.22.168 Anomalies in Data Sets. Anomalies were observed in the daily jet-grouting reports or DAS curves on the last ISG site, T30, insertion points T30 D006, T30 D012, T30 D018. Both the rpm and pull speed curves reflected fluctuating readings over the duration of the grouting campaign, rendering the curves unreadable. However, raw data indicated that each site was completely grouted within established parameters, as was empirically verified by the observance of grout returns. Based on data analysis and field observations by HBI, the automated grouting system’s response to changing site conditions produced the anomalies.
Automated grouting operations on the HBI drilling systems were controlled by a common proportional integral drive controller control loop feedback mechanism. The controller calculates an error value between a recorded variable in the process and the programmed variable or parameter. Based on the calculations, the loop adjusts the output value for that parameter. With the HBI system, the loop controlled the hydraulic system that operated the revolution speed of the monitor (rpm). This automated adjustment in the rpms occurred within an integral time measured in thousands of a second. For the
subject insertion points, the anomaly observed on the DAS curves was the system continuously correcting itself to maintain a constant rpm rate while being affected by conditions within and external to the grouting hardware, which caused binding on the monitor. Because the integral frequency was so fast, each time an instantaneous correction was made to speed up the rpms to compensate for the binding, another reading was taken before the speed was able to equilibrate, and the system thus decreased the rate to attain the programmed parameter. These opposing adjustments (faster and slower rpm rate swings) were indicated by the anomalous DAS readings, which cycled approximately every 10 seconds. Because these corrections were being made almost instantaneously, raw data indicated that average rpm rates and relative pull speed or retraction rates for the two-step settings used were being maintained within programmed parameters (ranging from 23 rpm and 26 in./minute and 32 rpm and 36 in./minute) for all three insertion points.
Once the problem was observed on the first location, it was corrected by HBI technicians by adjusting the integral time (sampling and adjustment frequency for the loop) during grouting of the subsequent two insertion point locations. Integral times on the second and third locations were increased by 0.015 and 0.020 seconds, respectively. This increase allowed corrections to the rpm speed to be made and the system to equilibrate to the adjustment before another data point was recorded, thus avoiding an opposing correction. Analysis of the problem by HBI personnel indicated that binding on the monitor, which caused the initial problem, may have resulted from changes in friction between the drill string and subsurface, but likely was caused by changes in hydraulic oil temperature and condition or swivel lubrication at the end of the project.
22.214.171.124 Refusal. The Drilling and Grouting Plan (VDR-291709) defined refusal as:
…30 seconds of vigorous drilling with less than 2 inches of penetration. Should penetration attempts utilizing the full range of drilling capabilities slow to a penetration rate of less than six inches in two minutes, this also shall be deemed refusal. Refusal for insertion points immediately adjacent to points having met refusal by this mechanical method, may be determined by judgment of the operator, with the concurrence of the observing STR, provided the vertical difference from the proven refusal depth is less than three feet. Upon reaching the specified depth or refusal, both the driller and ground man will visually confirm that the work area is clear, the driller will contact the pump operator and direct him to bring the pump up to pressure and high pressure grouting shall be initiated.
To simplify operations, HBI adopted the approach to determine refusal at any given insertion point by conducting 30 seconds of vigorous drilling with less than 2 in. of penetration regardless of penetration rates of adjacent points. Drilling was attempted to a total depth of 17 ft bgs for each insertion point located within trench sites and to 25 ft bgs for the soil vault site. Grouting was initiated from the target depth or the point of refusal to 4 ft bgs. Of the insertion points drilled in the 20 trench sites, 3% of the points encountered refusal between 0 and 8.9 ft, 24% of the points encountered refusal from 9 to 14.9 ft, and 73% of the points were drilled to depths between 15–17 ft. In drilling of the soil vault, ISG Site S14, refusal was met at a depth of 14.5 ft on the center location with each of the six perimeter locations being drilled to depths between 21 and 24 ft.
126.96.36.199 Grout Returns Management. Excess grout extruded to the surface via annular space along the drill stem or via previously drilled insertion points, producing grout returns. Returns and associated ground heave from saturated subsurface conditions signify thorough waste zone treatment. Figure 40 shows typical viscous grout returns, observed at the start of grout injection, and pillow-type returns, containing grout mixed with interstitial soil, which occur primarily after starting to retract the drill stem, and an example of ground heave. An optimal ISG operation will produce small volumes of grout returns and little evidence of ground heave, thus reducing the potential spread of contamination, aiding in site restoration, and resulting in a more cost-effective operation. As part of controlling radiological conditions during ISG, a limited exposure criterion was set to prevent overexposing personnel to radiologically contaminated material. Managing grout returns was a critical part of meeting this criterion. Managing returns also was dictated by the project safety basis (HAD-460) and associated basis documents, which assumed no returns from adjacent insertion points. In addition, Phase 2 close-out required that each site be backfilled and restored to existing facility grade and drainage. Control of returns and the degree of associated ground heave within grout returns basins were imperative to preclude disturbing the site (e.g., removing solidified grout returns) to achieve safe and acceptable close-out. Phase 2 grouting parameters were predicated on extensive Idaho National Engineering Laboratory research and development on simulated SDA waste (see Section 3.1 of the Phase 2 Work Plan). Higher densities in actual waste skewed operational parameters (e.g., retraction rates and rpms) toward the upper limit of experimentally derived ranges defined in the Phase 2 Work Plan.
To control the amount of grout returning to the surface, each drill rig was equipped with a dual-speed step function. The dual-speed function allowed the drill rig operator to increase rotations per minute, thus increasing the withdrawal rate. This function was used when the amount of grout returning to the surface was judged excessive by the project engineer or drill rig operator. The drill rig operator increased the rotations per minute at the direction of the STR or from observations of either grout returning to the surface through adjacent holes or ground heave. The drilling pattern was offset in conjunction with the step function. The original pattern was to grout every other insertion point, making primary and secondary passes through each site. Once production began, the project determined further separation between freshly grouted holes was necessary to reduce returns. Every third insertion point in the row was grouted, making primary, secondary, and tertiary passes through each site (Figure 41). Treatment of initial sites required trial and error to optimize this relational approach. Treatment of the first site, T49A, showed ground heave ranging from approximately 8 in. to 18 in. at the center of the site and a range in grout deliveries from 13 gal/ft to 9.5 gal/ft by varying the step function (Figure 42). During grout application on the first three Rig #1 ISG sites, nine insertion points exhibited excessive grout returns and ground heave upon initiation of grout injection because of localized saturation of the waste zone from primary and secondary passes; thus, this grout application was ceased.
Figure 40. Examples of grout returns and ground heave
During the grouting of the third site by Rig #1, T42A, another form of control was identified. Grouting was aborted in locations where grout returns could not be managed by the dual-speed step function. A second entry was attempted in these locations after the surrounding insertions were given time for the grout to set. In total, 12 locations were aborted and re-entered at this site. While implementing these options, the grouting parameters for each drill rig were quickly fine-tuned to optimize the ratio between the amount of grout returning to the surface and the amount of grout being injected into the subsurface. Figure 43 compares sites completed early in the project with those completed later, i.e., following optimization of grouting operations. Over the course of the project, 21 insertion point locations were re-entered for grout application. All but five of these reentries occurred in the first three ISG sites treated.
188.8.131.52 Retraction Rate Exceedance. Daily jet-grouting reports or DAS curves indicated an intermittent exceedance in the established retraction rate of 39 in./minute for specific insertion points associated with ISG Sites T45C, T42B, and T44. In each case, the HBI drill rig operator was conducting grouting operations at the upper allowable rotational setting of 39 rpms in order to control grout returns.
HBI’s automated grouting function was controlled by preprogramming the following three variables: step size, revolutions per step, and monitor rotation or rpms. As the rpms were increased by actuating the step function, so too was the retraction, at a related rate, assuming the other two variables remained fixed. In the case of the subject ISG sites, variability in air temperature, ground conditions, waste forms, and mechanical response caused the step size to drift. The steps increased by up to 1 in., causing the retraction rate to exceed the established parameters even though programming remained within the set parameters. Once this condition was observed, the maximum step setting for monitor rotation (rpms) was decreased from the upper parameter setting of 39 in./minute. This practice continued for the remainder of the project, even though a field change had been implemented to allow operations to exceed the upper retraction rate parameter to manage grout returns (see Section 184.108.40.206). Applying grout at the lower rates increased grout returns, which were closely monitored by RadCon to ensure operational safety.
3.6.2 Operational Refinements
Remedial actions typically involve field decisions. In the context of Phase 2 ISG, field decisions were defined as real-time refinements to ISG site-specific operating parameters. Field decisions were based on a combination of field observations, knowledge of the buried waste (e.g., waste form and container type), and professional judgment. ICP directed HBI to implement field decisions, which were noted in field logbooks. The following sections address these operational refinements. In each instance, DOE, DEQ, and EPA representatives were not present in the field, and the decisions had no impact on the performance goal of 80% of the maximum potential grout volume. Therefore, as the Phase 2 Work Plan (DOE-ID 2010) allowed, when Agency representatives were not present, treatment proceeded without delay, and ICP informed the Agencies of the field change after the fact.
Figure 41. Examples of primary, secondary, and tertiary passes through a site.
Figure 42. Examples of grout returns and ground heave at Site T49A.
Figure 43. Comparison of grout returns and ground heave between sites completed early in the project versus those completed later when grouting operations were optimized.
Other operational refinements were initiated through management observations and project team members. Resultant protocols were adopted and addressed in pre-job briefings. Table 9 lists these minor changes.
220.127.116.11 Discharge of Flush Water to the SDA Surface. The offsite demonstration showed that the containerized high-pressure system flush operation presented possible safety issues; thus, an alternate method involving discharge to the surface of the SDA was discussed and accepted by the Agencies during the April 26, 2010, teleconference. The alternate approach allowed flush water from the upper system (i.e., high-pressure grout supply system) to be discharged to SDA ditches. Water from the drill stem and nozzle could be discharged to grout returns basins, as the additional water volume in the returns area was inconsequential and would evaporate. The containerized flush operation was retained as an optional procedure, with the clarification, agreed to by the Agencies, that the container drain valve could not be discharged over a just-grouted or to-be-grouted area.
The approved flush operation was included in the second revisions of HBI’s O&M and Drilling and Grouting Plans. In compliance with the revisions, the high-pressure grout supply hose was disconnected at the slick line, on the rear of the rig, and directed to an excess grout basin, constructed outside of and immediately adjacent to each ISG site. Inline product was displaced into the excess grout basin, then the hose was redirected to local drainage to complete the fresh water flush. To complete the flush of the drill rig, the clean high-pressure hose was reconnected to the slick line and water was pumped through the system into the grout returns basin. Section 2.3.3 describes this operation in detail.
Wet decontamination was not performed on the project; thus, additional requirements to manage decontamination water were not required.
18.104.22.168 Fire Safety Measures. An inspection of the ISG site, conducted June 29, 2010, by the RWMC fire protection engineer, identified empty wooden pallets on the SDA as a fire hazard. The issue was resolved by implementing the following compensatory measures: (a) combustibles were limited to 1 day’s supply, (b) no more than 25 empty pallets were left on the work site at the end of a work day, (c) empty pallets were transferred to a laydown area where the pallet owners picked them up, and (d) the pallets were neatly stacked and combustibles and potential ignition sources (e.g., equipment) were kept a minimum of 35 ft from the pallets. The fire protection engineer periodically visited the project site to verify these measures.
22.214.171.124 High-Pressure System Isolation. During mid-June, DOE facility representatives opined that personnel working on the monitor and nozzle assembly were not sufficiently protected from the high-pressure system. The HBI O&M Plan was revised to mitigate the potential hazard by requiring the drill rig operator to turn the rig off and pass the ignition key to the person working on the monitor or nozzle. After completing the activity and verifying that personnel had exited the grout returns basin, the worker returned the key to the drill rig operator. In cases requiring repositioning of the drill mast (i.e., operation of the drill rig), protective steps were added to first verify zero energy in the system, cut power to the high-pressure pump, and remove the high-pressure hose from the slick line on the rear of the rig. Revisions were issued for the HBI O&M Plan, Drilling and Grouting Plan, and job safety analysis. Changes were communicated in tailgate training provided to the workforce on July 13, 2010.
126.96.36.199 Emergency System Flush. During July, weather conditions necessitated a rapid approach to securing the drilling and grouting system to provide for the safety of personnel and equipment. This approach primarily involved the adoption of an emergency flush operation. In accordance with
Section 1.4 of the Phase 2 Work Plan, the approach was discussed in an Agency teleconference on July 27, 2010, confirmed in a follow-up email from DEQ, and documented in this interim completion report. Flush operations and associated management of rinse water were modified to include steps to discharge rinse water into the subsurface with the nozzle inserted in the monitor. This option was implemented twice during the project, on ISG Sites T45C and T48A, in each case in response to a weather emergency when existing procedures could not be safely implemented.
Research was performed with additives that could be introduced into the grout mix to increase the set time of the grout to delay the need for rinse operations up to a day, an option that was not pursued during the project.
188.8.131.52 Retraction Rate Parameter. During a review of drilling data, DEQ personnel observed that the drill string retraction rate exceeded the Phase 2 Work Plan upper value of 39 in./minute for several insertion points. After careful review of operating data and discussion at length, DEQ, DOE, and CWI concluded during an August 12, 2010, phone teleconference (the EPA representative was not available) that (a) this was an acceptable condition arising from efforts to minimize grout returns in keeping with the ISG safety basis and (b) implementation of the field change had not and would not jeopardize the 80% performance objective. At the conclusion of the call, DOE notified DEQ and EPA of an ISG field change. The field change was entered into the ISG Project logbook as follows:
Field change: ISG operations are to remain within the operating parameters specified in Section 184.108.40.206 of the Work Plan to the maximum extent practicable. However, deviations—such as to a higher retraction rate (item 20b in the Work Plan)—are allowable to reduce grout returns. Such changes must not jeopardize the overall performance objective (i.e., at least 80% of the maximum potential volume for the ISG site).
3.6.3 RadCon Project Summary
Baseline surveys of the HBI’s Rig #1 and support equipment, conducted May 17, 2010, indicated no contamination present. Baseline surveys of the HBI’s Rig #2 and support systems conducted
June 14, 2010, also indicated no contamination present. Conditions for environmental and worker safety were monitored over the course of the project relative to the radiological work permit. No releasable airborne contamination was observed via air sampling or personnel monitoring techniques. General area surveys were routinely performed, indicating consistent radiation levels ranging between <0.5 mR/hr and <5.0 mR/hr, which were managed by implementing controls stipulated in the radiological work permit and work control. Controls included placing soil over contaminated areas and increasing boundary distancing. Specific occurrences observed at the specific ISG sites in excess of these norms and, thus, requiring additional action to maintain radiological control, are noted in Table 9.
After completion of ISG operations, HBI rigs were surveyed for release. Contamination detected on the base plate and foot of each rig ranged from 20,000 dpm on Rig #2 to 120,000 dpm on Rig #1. The bottom portion of each monitor was removed as designed and turned over to WGS for disposal. Rig #2 and Rig #1 final surveys, conducted August 25 and 26, 2010, respectively, verified “no rad added”; thus, each was released to HBI.
3.6.4 Field Oversight and Construction Management
The DOE-ID project manager ensured that DEQ and EPA were apprised of ISG activities (e.g., startup testing, grouting, and pre-final inspections). The DOE-ID project manager delegated authority to ICP personnel to notify DEQ and EPA on DOE’s behalf when individual ISG sites were completed. The DOE-ID project manager informed DEQ and EPA of this protocol. In all instances, ICP apprised the DOE-ID project manager of communications with DEQ or EPA concerning ISG issues.
An Agency site visit was conducted July 13 and 14, 2010. Attendees included DOE, DEQ, EPA, and CWI representatives. Operations were not being conducted during the visit because of high winds. However, personnel were able to tour Site T53A and discuss general operations. The DEQ representative expressed concern over the implementation of procedure refinements involving grout returns management and how decisions were being made to discontinue grout application at a particular insertion point. His concerns were satisfied by the CWI project engineer through explanation of returns management being exercised primarily to control returns from adjacent locations as opposed to the injection point being treated. Reentry of previously grouted insertion locations was also discussed.
3.7 Pre-Final Inspection
The Agencies elected to forego the typical pre-final inspection strategy described in the Phase 2 Work Plan (e.g., submittal of the draft report as a secondary document that would be completed later as part of the final comprehensive remedial action report for OU 7-13/14). Because pre-final inspection was straightforward with no identified deficiencies, the Agencies signed off without requiring submittal of a draft document. Appendix C contains the final, Agency-approved pre-final inspection report in the form of two signed memoranda.
Pre-final inspection occurred in two parts. The first pre-final inspection addressed the westernmost 8 of the 21 sites identified for treatment. The Agencies agreed to inspect the first eight sites early to facilitate uninterrupted progress of ongoing ARP construction (see Figure 44). DOE provided a draft pre-final inspection checklist to DEQ and EPA and the three Agencies finalized the checklist in advance. Agency representatives conducted a pre-final inspection for the western group of eight ISG sites on July 13 and 14, 2010, and they reviewed site-by-site grouting data and photographs. Each Agency concurred that Phase 2 remediation was complete at ISG Sites T34, T36, T42A, T45A, T45B, T49A, T49B, and T53A (see Figure 45).
Figure 44. Concurrent in situ grouting and Accelerated Retrieval Project VII construction—looking west from the center of the Subsurface Disposal Area, the center rig is the in situ grouting Rig #1; to the right, another rig pounds pilings for the Accelerated Retrieval Project VII retrieval enclosure; and, to the left, a crane manipulates materials for retrieval support trailers.
Figure 45. Eight in situ grouting sites completed in the western portion of the Subsurface Disposal Area.
On August 8, 2010, the Agencies were notified—no less than 14 days in advance as required by the Phase 2 Work Plan—that pre-final inspection of the remaining 13 sites would occur approximately August 26, 2010. Pre-final inspection took place August 30, 2010, using the same, previously approved checklist. Agency representatives conducted pre-final inspection through site visits and by reviewing site-by-site grouting data and photographs to validate compliance with remedial design and other elements of the Phase 2 Work Plan for the remaining 13 sites (see Figures 46 and 47). Each Agency concurred that Phase 2 remediation was complete at ISG Sites S14, T25, T30, T35, T42B, T44, T45C, T46, T48A, T48B, T49C, T53B, and T56.
By signing the August memorandum in Appendix C, the Agencies accepted the two memoranda together as the formal pre-final checklist and pre-final inspection report. They concluded that that Phase 2 remediation is complete with no deficiencies.
3.8 Phase 2 Close-Out
Closure concepts for the Phase 2 OU 7-13/14 ISG Project apply to two scenarios: individual sites (i.e., the cold test site and 21 ISG sites) and Phase 2 close-out after ISG is complete.
Figure 46. Nine in situ grouting sites completed in the south-central portion of the Subsurface Disposal Area.
Figure 47. Four in situ grouting sites completed in the southeastern portion of the Subsurface Disposal Area.
3.8.1 Interim Closure of Individual In Situ Grouting Sites
Individual sites, including the cold test site and 21 ISG sites, were restored throughout grouting operations. Restoration included backfill and contouring using stockpiled overburden from site preparation. Additional backfill material was obtained from an approved INL Site source. ISG sites were contoured to promote drainage. As individual sites were completed, interim closure also included removing barricades and postings.
3.8.2 Phase 2 Close-Out
Phase 2 close-out occurred after the second pre-final inspection. Close-out involved HBI demobilization and turnover of the project area to RWMC facility management. Demobilization of HBI equipment included disassembly of radiologically contaminated portions of the contamination control hardware (see Figure 48). Disassembly was conducted as designed (VDR-299862), and sacrificial components were wrapped and placed into waste containers and turned over to WGS (Figure 48). ICP RadCon determined no decontamination of HBI equipment was required. HBI equipment demobilization was completed on September 3, 2010.
Phase 2 close-out also included restoring SDA infrastructure to acceptable pre-ISG condition. Turnover of the defined ISG treatment sites to RWMC facility management included the removal of temporary barriers and fences and backfill and grading of each area to existing facility grade and drainage (Figure 49). Close-out was accomplished in stages. Turnover of the westernmost eight sites (see Figure 45) occurred on August 5, 2010, following Agency pre-final inspection of the sites. The two-part pre-final inspection facilitated uninterrupted progress of ongoing ARP VII construction. Turnover of the remaining ISG areas occurred on August 31, 2010, following the second pre-final inspection. Close-out also involved the confirmed decontamination of a backhoe bucket and the return of all equipment to
Figure 49. Site backfill and grading.
construction management. Final disposition of waste at the ICDF and closure of the CERCLA storage unit occurred on September 28, 2010. Demobilization of leased field trailers and personnel support facilities was completed on September 29 and associated underground temporary utilities (e.g., wiring, conduit, red mud) were removed on October 1, 2010, per facility design. Responsibility for restoration of road surfaces was formally transferred to the RWMC facility manager to be addressed with other road repairs scheduled for fall 2010.
3.9 Post-Construction Operations and Maintenance
ISG was successfully implemented in the 21 locations specified in the Phase 2 Work Plan and each site has been restored as required. Therefore, O&M of grouted areas beyond routine O&M for the entire SDA (e.g., subsidence repairs) are not required.4. WASTE MANAGEMENT
The ISG Project generated and managed waste in accordance with Section 5 of the Phase 2 Work Plan (DOE-ID 20I 0). T he following section outlines waste generation, management , and disposal during and after ISG. ICP WGS managed Phase 2 ISG waste in compliance with company procedures.
Not all anticipated waste streams identified in the Work Plan (DOE-ID 20 I 0 , T abl e 5-1) were generated. Table 10 outlines the project waste streams, associated volumes, and storage and disposal locations, outside of the SDA. Beginning June 9, 2010, CWI force account personnel collected industrial waste on a regular basis (i.e., two to three times per week) for disposal at the INTEC CERCLA Landfill. In two instances, waste was placed into the RWMC conditional waste dumpster (nonradiological absorbed oil) and subsequently disposed of as industrial waste. The final volume of industrial waste was removed from the project site on September 3, 2010. CERCLA low-level waste was collected throughout the project in metal waste boxes and stored in a CERCLA storage area located rn the ISG operations staging area (Figure 16).The entire quantity of CERCLA low-level waste was shipped to ICDF and placed into a disposal cell 011 September 28, 2010.
Grout returns and slurry, unused neat grout, and purge water from daily equipment cleaning were disposed of in the SDA and covered with soil. Used drill string monitors and attached bits were placed into grout returns basins after RadCon technicians wrapped the bits in yellow plastic (Figure 50). They were subsequently covered with soil during site restoration. In total, five monitors and one W-ft monitor extension were used to conduct ISG operations. Disposal of these wastes were tracked under Integrated Waste Tracking System Waste Disposal and Determination Form, WD DF RWMC 1004. Table 11 provides monitor disposal location information
The ISG waste was tracked, packaged, and labeled according to company procedures (e.g., GDE-233 and disposal facility requirements). Low-level waste containers were also labeled with an Integrated Waste Tracking System bar code. Information pertaining to project waste (e.g., waste characteristics , waste generation and storage locations, and shipments) is maintained in the Integrated Waste Tracking System . A logbook was maintained for the ISG CERCLA storage area to track waste entering the area. Pertinent information from the log sheets was also incorporated into the tracking system.
Figure 50. Discarded monitors positioned in grout returns basins.
Compliant and appropriate packaging was selected with the assistance of Packaging and Transportation personnel. CERCLA low-level waste debris generated from the project was placed in Department of Transportation Industrial Packaging l and Type A metal boxes. The feet from both drill rigs were included in the low-level debris waste stream and in the metal boxes. Blocking and bracing were required in the packaging to stabilize the drill rig feet. Containers were dosed in accordance with the manufacturer's closure instructions.
All waste generated by the ISG Project has been disposed of at appropriate disposal facilities, and the temporary CERCLA storage unit for ISG bas been dosed. lndt1strial waste was disposed of at the INTEC CERCLA Landfill. CERCLA low-level debris waste was transported to ICDF in accordance with Department of Transportation requirements and disposed of in the Grid K-10, Lift 2B location. Grout returns, sluny , unused neat grout, purge water from daily equipment cleaning and drill string monitors were disposed of in the SDA and covered with soil in accordance with the Phase 2 Work Plan (DOE-ID 2010}.5. CERTIFICATION THAT THE REMEDY IS OPERATIONAL AND FUNCTIONAL
The Phase 2 OU 7-13/14 ISG Project was completed in accordance with the OU 7-13/14 Record of Decision and the Phase 2 Work Plan and achieved requirements as measured by the predetermined performance standard. This component of the OU 7-13/14 selected remedy is complete and the Agencies certify that it is operational and functional.
Observations and lessons learned associated with the OU 7-13/14 Phase 2 ISG Project were compiled by various groups throughout the project. This approach assesses what went right, what went wrong, and what improvements are needed from varying perspectives. Redundancies and differing opinions relative to the similar subjects are intentionally reported below to preserve those various perspectives.
6.1 Project Observations and Lessons Learned
The following sections address lessons leaned for various stages of the project compiled from notes and conversation with key CWI project contributors.
Experienced authors wrote specifications and contract documents, avoiding the need for change notices. Award criteria in the request for proposal required applicable experience that successfully precluded unqualified bidders. The performance specification allowed enough leeway for HBI to move forward with the work. The general provisions and special conditions used in the subcontract were effective.
Based on lessons learned from the 2004 beryllium grouting (Lopez et al. 2005), CWI required HBI to be responsible for decontamination, with CWI reserving the right to back-charge any further required decontamination. This incentivized HBI to submit an effective contamination control design and to maintain control in the field with oversight from RWMC RadCon to avoid back-charges. Decontamination was not required at the end of field operations.
To avoid problems with drilling the hardpan layer, which was problematic on the Beryllium Project, the specification allowed more leeway for the subcontractor to bring their drilling and grouting expertise to bear and use the full capacity of their drilling hardware.
Public meetings were conducted with interest groups (e.g., Citizens Advisory Board) and were well attended. The project was well communicated to stakeholders and comments were addressed. DOE Idaho Operations Office upper management was briefed frequently, and their interaction and support at all stages of the project helped keep activities on track. In addition to communicating with stakeholders and keeping DOE Idaho Operations Office well informed, early planning of the project involved EPA and DEQ. Both EPA and DEQ were briefed and participated in the review of documents related to the project. Both EPA and DEQ concurred with DOE on the direction and implementation of the project.
Safety concerns for the high-pressure system were emphasized throughout the project. Safety features not commonly employed in jet-grouting operations were installed, such as redundant overpressurization systems, a limit switch to stop the jetting operation below grade, whip socks, and rupture shielding.
The construction specification, “Operable Unit 7-13/14 In Situ Grouting” (SPC-1162), required that HBI follow a rigorous process of design, design verification, and testing for the ISG system and associated operating procedures. The design and design verification documents were submitted as vendor data and were approved before work started. The specification required HBI to design the pressure system with new parts compliant with the rated system pressure. Subject matter experts from CWI inspected the system during the offsite and onsite tests to verify compliance of the pressure system to the specification document.
CWI rigorously communicated project requirements to HBI. HBI’s Pressure Design Report was developed specifically (as required in the specification) to ensure that components used in the high-pressure system were adequate for the service. It required that each pressure system component be inspected or tested against the specifications. HBI was required to carefully design and document the pressure system to comply with the intent of consensus codes and standards.
HBI’s upper management championed the CWI Integrated Safety Management philosophy from the start and ensured that philosophy was understood and grasped by all members of the project team. HBI’s attention to safety was impressive; first-aid cases, incidents, and accidents did not occur during the project.
6.1.3 Subcontractor, Teamwork, and Field Changes
Communications were open, and the project team was staffed with people who were authorized to and made decisions when needed. For the most part, decision-makers and other staff remained constant from beginning to end. Early engagement with support organizations (e.g., Safety, Operations, and RadCon) helped build a cohesive team and enabled early decisions and agreements so that later conflicts did not arise. CWI’s good relationship with HBI allowed final negotiations of minor claims to be conducted professionally and in the best interests of all parties.
Demands of the INL Subcontractor Requirements Manual (TOC-59) should be better communicated to the subcontractor.
A clear chain of command between CWI and HBI was provided by the CWI Construction organization. This protocol was established early in pre-construction planning meetings and remained consistent throughout the project. CWI personnel roles and responsibilities were clearly documented in the project-specific health and safety plan.
The schedule and the hours worked on this project were consistent with an established 4 x 10 work shift. Extended work hours were requested well in advance to allow for personnel to plan. Support organizations were pre-approved at the start of field operations to work shift plans to address needed overtime for daily reporting and site restoration.
HBI hired a quality officer who was familiar with CWI processes and procedures and who was very valuable in developing an HBI company-level quality plan and a subsequent project plan for HBI that met requirements for a Quality Level 3 high-pressure system.
System design and operating parameters recommended in the Phase 2 Work Plan and the construction specification were based on past successful ISG research and development at the INL Site. A performance standard was established based solely on a volumetric relationship between area treated and the grout delivered to the subsurface.
An extensive reassessment of SDA geophysical data significantly decreased the area requiring treatment.
Successful implementation of the segmented hazard assessment document (HAD-460) as the project safety basis worked well, allowing the project to operate as a less than Hazard Category 3 facility within a nuclear facility. The project decision to seek work authorization via the MSA process facilitated facility support and improved work processes.
Selecting a vendor that used an excavator-mounted drill rig, as recommended via the specification (SPC-1162) based on past ISG treatability studies, greatly enhanced safety, production, and waste minimization.
The RWMC RadCon organization applied lessons learned from the Beryllium Project and eliminated grout containment units and the drill string shroud.
Separate planned work orders written for the ISG work and force account support scope streamlined pre-job briefings and allowed unrelated work tasks under one work order to proceed when work under the other work order was delayed.
The project manager selected a web-based application to upload the vast amount of vendor- supplied ISG data into the Waste Information and Location Database. Uploaded data were efficiently validated against HBI daily site reports and corresponding insertion point spreadsheets. The application allowed project personnel to use the data and quickly produce various scenarios for decision-making on the project. The application also generated reports to provide information on drilling and grouting parameters by area and for Agency interim closure approval. Additionally, a brief daily review of drilling log data, as provided by the subcontractor in graphical format, proved to be a valuable management tool. Compliance with key project specifications were rapidly verified using graphical means, mitigating potential adverse project impacts.
The hardpan layer encountered at the SDA on the Beryllium Project posed no problems as HBI was allowed to drill using the full capacity of the rig. Excessive grout returns and ground heave were issues on the first few ISG locations.
Section 220.127.116.11 discusses these issues and the actions taken to mitigate the problems. Future users of this technology should recognize that void fraction in buried waste is quite variable and will always differ from simulated test locations. Having the technical ability and regulatory latitude to vary the amount of grout injected per linear foot is necessary to control the outcome.
Impurities in the dry grout product (binder) caused nozzle plugging and abnormal wear on the high-pressure pump during the entire course of the project. Section 18.104.22.168 describes the actions taken by the subcontractor to mitigate this issue. The quality of the binder was a significant project risk that should have been previously identified and mitigated. A secondary supplier of the binder should have been identified and used when the first supplier could not correct the issue.
Super sacks were used to deliver the binder material to the silo as described in Section 22.214.171.124.3. Initially, emptying the sacks into the silo proved to be difficult because the product bridged the bottom port in the sack and would not flow into the silo. The subcontractor refitted each sack with a zip tie that could be cut remotely, and the port was trimmed to increase flow into the silo. A larger port in the bottom of the sack would improve this operation.
6.1.5 Offsite Test and Demonstration
Full-scale offsite acceptance testing and operations demonstration took place at HBI’s facility in Santa Paula, CA. HBI provided the test plan and acceptance criteria and CWI approved through the ICP vendor data system. By design, the offsite demonstration allowed HBI to modify equipment under their authority using their shop capability. The demonstration included each field and facility support organization and served as training and team building for HBI and CWI participants. CWI also spent time preparing HBI, who had not worked at a DOE site and had only limited radiological experience, for the MSA and onsite demonstration. The appropriate personnel attended the offsite demonstration (e.g., RadCon technicians, IH, safety, nuclear facility manager, engineering, quality assurance) to observe and participate in the demonstration, thus avoiding questions and problems which would have required time and money to address later in the project.
6.1.6 Project Planning, Management, and Company Systems
The project schedule was accelerated because of the segmented approach taken in writing the hazard analysis document. Writing an addendum to an existing safety analysis report would have required much more time for reviews and approvals.
The vendor data system worked well. HBI was impressed with how quickly CWI responded to their vendor submittals and helped resolve issues.
The MSA was planned and managed effectively. Though the MSA was not required, it was an effective forum for ensuring that all concerns were addressed, saving time in the long run. A dedicated RWMC facility operations individual, aided by a subcontractor, prepared for the MSA. Therefore, the MSA did not add administrative burdens to the project managers or project engineer, who could then focus on satisfying technical, safety, and operational requirements. The level of MSA was appropriate for the grouting work. The MSA was successfully completed, and a readiness review was not required.
By implementing lessons learned from past ISG studies, the final project cost was lower than budgeted because contingencies were not required and only qualified bidders were considered for the project. The bid selection process was formalized and focused on technical attributes of each vendor before cost was a factor.
6.2 Management Self-Assessment Lessons Learned
Diverse members of the project team assembled to discuss lessons learned after the OU 7-13/14 ISG Project MSA, which ended June 3, 2010. The sections below briefly describe each positive and negative attribute, as well as recommendations to mitigate future issues on similar projects.
- The offsite demonstration was very beneficial. Project representatives were able to observe the equipment operate and identify safety or process issues that were addressed prior to equipment mobilization.
- The scope described in the MSA Plan (PLN-3456) was well defined. The plan clearly defined what was to be assessed and what scope was excluded in the MSA. Clear definition kept the effort focused.
- The project dedicated key support personnel to the MSA. Technical support helped the MSA team find and understand what they needed, and administrative support collected and organized the objective evidence very effectively.
- Early involvement by DOE and DEQ helped provide uniform and consistent project objectives. DOE and DEQ participation in the offsite visit contributed to this benefit.
- The RadCon organization provided very strong support that helped HBI become proficient in working in a radiological environment.
- One RadCon technical basis document was created, so all necessary information for this project was in one place.
- RadCon training was tailored to project-specific conditions, which helped focus learning objectives and made training more effective.
- Drafts of vendor data reports were worked informally in advance of official submittal, which reduced re-work and saved time.
- HBI did not understand the program requirements documents. Additional emphasis could be placed on those elements of program requirements documents relative to electrical equipment and lockout/tagout.
- HBI did not have a complete understanding of the MSA and what they would be required to do. A contractual obligation for ownership of delays and pre-start findings should be established.
- Vendor data submittals were delayed for many reasons. The subcontractor should be incentivized to submit data per the schedule.
- The quality of the vendor data reports did not meet expectations. The subcontractor should be incentivized to submit quality reports the first time.
- HBI was not at the pre-bid meeting held at RWMC. Attendance at the pre-bid meeting should be mandatory for all bidders.
- HBI’s electrical equipment was not up to code. An electrical inspector should have participated in the offsite demonstration to identify issues before mobilization of equipment. See also Item #1 in this section.
- Requirements and controls established by the hazard assessment document were not clear.
- The MSA Plan was modeled after a plan for a Hazard Category 2 facility. More care should have been given to ensure review criteria were appropriate for a less than Hazard Category 3 facility.
- Documents referenced in objective evidence were not always immediately available. Objective evidence should be reviewed, and relevant references should be put in the objective evidence file.
- Subcontractor equipment manuals should be submitted as vendor data early in the process. See also Item #1 in this section.
- The MSA team lost a member during the review and a backup had not previously been identified.
- Many demands were placed on the STR during the subcontractor mobilization and MSA preparation period. Activities should have been evaluated and delegated more effectively to allow the STR to focus on high-priority activities.
- The STR and field team leader were confused about their roles and responsibilities. Management should clearly articulate their duties.
- DOE facility representatives were not cognizant of process details before the MSA. Facility representatives may have benefited from the offsite demonstration and a detailed briefing of the equipment and the operation.
- The field team leader and STR should fully understand all the objective evidence. Schedule demands prohibited a complete understanding.
- The qualified watch list was not user-friendly and did not lend itself to timely updates. Training requirements were not completely identified in a timely manner.
6.3 Hayward Baker Observations and Lessons Learned
At the completion of ISG operations, the HBI field crew and project managers gathered informally to discuss what did and did not work well during the project. The following comments and suggested changes were presented by HBI following this discussion.
6.3.1 Project Preparation
The project specification (SPC-1162) identified the potential to encounter a hardpan layer of soil experienced during the 2004 grouting project. Subsequent conversations verified that this issue may, in part, have been associated with constraints placed on the drilling contractor. However, because of this concern, HBI elected to outfit the drill rigs with a robust drilling system that included a top hammer and extra-heavy drill tooling. The extra-heavy tooling required the monitor and drill rods to be combined into a single system rather than the typical two-piece system. Based upon the actual conditions encountered, a traditional monitor and drill rod would have been robust enough to penetrate to total depth without added wear on the equipment.
HBI could have better prepared field personnel to address requirements established in their quality project plan and thus comply with procurement protocol for CWI Quality Level 3 items.
To perform the work onsite, HBI completed multiple training courses. Some of the training was beneficial to the individuals involved and some of the information covered was unnecessary and did not apply to the specific work being performed.
Radiological Worker II training taught personnel how to properly handle various radiological situations. The course consisted of a one-day class followed by a test and a one-day practical. For future subcontractor training, conducting the practical before the test would be beneficial. The test encompassed much material that was new to individuals in the class and was difficult to prepare for in such a short time. Having the practical before the test would further clarify the classroom portion.
HBI was required to attend high-pressure system assembly training. The information given did not apply to the system being assembled for the ISG work.
HBI regretted their decision not to take lockout/tagout training, which was originally scheduled for select employees. Onsite situations occurred when equipment lockout for repairs or maintenance was needed. Because HBI personnel were not trained, a lockout/tagout procedure involving ICP oversight personnel was required, taking added time and effort.
The subcontract specification required HBI to design, verify, and test a system that was capable of operating at 80% of the system rated pressure. This provided a safe and functional system design.
Traditionally, HBI uses whip checks as hose restraints; because of high-pressure safety concerns, whip socks were used. Whip socks became a preferred way of restraining a hose in the event of a failure, and HBI is now using them on other projects.
Other devices that were implemented to help mitigate hazards associated with the high-pressure grout system and equipment hydraulics included a green light on top of the excavator cab that flashed when the hydraulics were disengaged, and a shroud that covered the discharge end of the high-pressure pump. Both of these features helped keep personnel safe when operating in or around the equipment.
6.3.4 RadCon Support
CWI had full-time RadCon technicians and IH coverage for the project. RadCon technicians were very valuable in handling radiological concerns during the project. The IH assigned to the project was familiar with the processes of the INL Site and proved to be helpful in keeping a safe working environment.
6.3.5 Preproduction Testing
HBI could have better understood the subcontract specification requirements for electrical systems. CWI should have inspected electrical systems more thoroughly and facilitated compliance with specification requirements before mobilizing to the site.
The offsite test pit was not representative of actual conditions within the SDA. The constructed waste pit was comprised of much looser material; thus, parameters used in the offsite test varied from actual production parameters. Testing did, however, identify system and operational improvements and provide beneficial personnel training.
6.3.6 Improvements for Future Projects
In conducting future projects, the use of a retarding additive for grout should be considered. The procedure developed for flushing the system, requiring shutting down the drill rig and managing the ignition key, was time-consuming. A cement retarder to eliminate the need for some flush operations would be beneficial.
6. Summary of Lessons Learned
On September 20, 2010, CWI provided the following summary of lessons learned at DOE’s request:
- Two operational demonstrations were performed, the first at HBI’s facility and the second at the INL Site. These demonstrations allowed project personnel to evaluate the operation and provide corrective actions prior to hot work in the facility.
- Some issues could have been identified earlier in the project if DOE facility representatives and electrical inspectors had participated in the offsite demonstration.
- An MSA was performed even though it was not required. The MSA ensured project readiness and was extremely valuable.
- HBI had never worked at a DOE facility, so increased support during preparations was required; management presence in the field helped mitigate issues.
- The CERCLA Phase 2 Work Plan was developed with flexibility to allow for field changes as conditions evolved and operational issues were identified.
- Two different nozzle orientations were incorporated into the drill design. One orientation caused premature failure, so the backup orientation was used for the duration of the project.
- Cement was delivered in 2,000-lb sacks, and was mixed onsite by a small batch plant for each drill rig. In previous projects, grout was mixed offsite and delivered. Onsite mixing was much more efficient.
- HBI retained a full-time technician to ensure maintenance and repairs were performed in a timely manner.
- By adjusting the drill retraction rate while maintaining constant pressure and flow, grout returns to the surface could be closely monitored and controlled.
- To control contamination, devices were designed into the drilling platform and operations were curtailed during high winds to avoid contamination spread.
- Early involvement by the Agencies during development of project implementation parameters, coupled with frequent communication and cooperation among Agency representatives, allowed for quick resolution of issues and facilitated implementation of the selected remedy.
- The fixed-price contract with fixed unit price for grout volume and drilling depth worked well.
7. SCHEDULE AND COST SUMMARY
Figure 51 presents a summary schedule of events for the preparation, execution, and completion of the Phase 2 ISG remediation. On April 13, 2009, the project was identified as American Recovery and Reinvestment Act scope, and planning was immediately started. With Agency concurrence, tasks were initiated in advance of the Work Plan approval to accommodate schedule constraints. The procurement of the subcontractor was expedited to ensure fieldwork could commence in spring 2010. The request for proposals was issued October 1, 2009, and the subcontract was awarded on December 10, 2009. The hazard assessment document (HAD-460) was prepared and transmitted to DOE on October 29, 2009, and approved by DOE on November 25, 2009 (Harshbarger 2009).
Figure 51. Summary schedule of events for the preparation, execution, and completion of the Phase 2 In Situ Grouting Project remediation.
The Phase 2 Work Plan assumed the fieldwork would take up to two field seasons. HBI's equipment experience , and favorable weather reduced drilling and grouting to one field season.
Funding was provided under the American Recovery and Reinvestment Act (Public Law 111-5) with the goal to complete fieldwork by 2011. Table 12 identifies the estimated cost as documented in the Phase 2 Work Plan and the actual project costs for the Phase 2 ISG Project through January 2, 2011. Cost savings are attributed to HBI production rates.Table 12
10 CFR 830 Appendix A, 2009, “Derived Air Concentrations (DAC) for Controlling Radiation Exposure to Workers at DOE Facilities,” Code of Federal Regulations, Office of the Federal Register, April 21, 2009.
10 CFR 830 Subpart B, 2009, “Management and Administrative Requirements,” Code of Federal Regulations, Office of the Federal Register, April 21, 2009.
29 CFR 1910.120, 2010, “Hazardous waste operations and emergency response,” Code of Federal Regulations, Office of the Federal Register, June 15, 2010.
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VDR-300568, 2010, “Demonstration Test Plan for Off INL Site Demonstration-CC/SO Test,” Rev. 2, Hayward Baker, Inc., May 13, 2010.
VDR-301030, 2010, “Pressure Design Report Operable Unit 7-13/14,” Rev. 3, Hayward Baker, Inc., May 17, 2010.
VDR-303383, 2010, “Pressure Design Verification Report No. 2 Operable Unit 7-13/14 In Situ Grouting,” Rev. 2, Hayward Baker, Inc., June 9, 2010.
VDR-306854, 2010, “Demonstration Test Report for Operable Unit 7-13/14 In Situ Grouting,” Rev. 1, Hayward Baker, Inc., May 17, 2010.
VDR-307812, 2010, “Test Configuration Certification,” Rev. 0, Hayward Baker, Inc., May 25, 2010. VDR-324809, 2010, “DAS Data/Drilling and Grouting Logs – T-34 Location – OU 7-13/14 In Situ Grouting,” Rev. 0, Hayward Baker, Inc., August 11, 2010.
VDR-324816, 2010, “DAS Data/Drilling and Grouting Logs – T-36 Location – OU 7-13/14 In Situ Grouting,” Rev. 0, Hayward Baker, Inc., August 11, 2010.
VDR-324825, 2010, “DAS Data/Drilling and Grouting Logs – T-42A Location – OU 7-13/14 In Situ Grouting,” Rev. 0, Hayward Baker, Inc., August 11, 2010.
VDR-324850, 2010, “DAS Data/Drilling and Grouting Logs – T-42B Location – OU 7-13/14 In Situ Grouting,” Rev. 0, Hayward Baker, Inc., August 11, 2010.
VDR-324866, 2010, “DAS Data/Drilling and Grouting Logs – T-45A Location – OU 7-13/14 In Situ Grouting,” Rev. 0, Hayward Baker, Inc., August 11, 2010.
VDR-324873, 2010, “DAS Data/Drilling and Grouting Logs – T-45C Location – OU 7-13/14 In Situ Grouting,” Rev. 0, Hayward Baker, Inc., August 11, 2010.
VDR-324884, 2010, “DAS Data/Drilling and Grouting Logs – T-46 Location – OU 7-13/14 In Situ Grouting,” Rev. 0, Hayward Baker, Inc., August 11, 2010.
VDR-324894, 2010, “DAS Data/Drilling and Grouting Logs – T-48A Location – OU 7-13/14 In Situ Grouting,” Rev. 0, Hayward Baker, Inc., August 11, 2010.
VDR-324903, 2010, “DAS Data/Drilling and Grouting Logs – T-48B Location – OU 7-13/14 In Situ Grouting,” Rev. 0, Hayward Baker, Inc., August 11, 2010.
VDR-324908, 2010, “DAS Data/Drilling and Grouting Logs – T-49A Location – OU 7-13/14 In Situ Grouting,” Rev. 0, Hayward Baker, Inc., August 11, 2010.
VDR-324929, 2010, “DAS Data/Drilling and Grouting Logs – T-49B Location – OU 7-13/14 In Situ Grouting,” Rev. 0, Hayward Baker, Inc., August 11, 2010.
VDR-324944, 2010, “DAS Data/Drilling and Grouting Logs – T-53A Location – OU 7-13/14 In Situ Grouting,” Rev. 0, Hayward Baker, Inc., August 11, 2010.
VDR-327675, 2010, “DAS Data/Drilling and Grouting Logs – T-25 Location – OU 7-13/14 In Situ Grouting,” Rev. 0, Hayward Baker, Inc., August 24, 2010.
VDR-327689, 2010, “DAS Data/Drilling and Grouting Logs – T-35 Location – OU 7-13/14 In Situ Grouting,” Rev. 0, Hayward Baker, Inc., August 24, 2010.
VDR-327694, 2010, “DAS Data/Drilling and Grouting Logs – T-44 Location – OU 7-13/14 In Situ Grouting,” Rev. 0, Hayward Baker, Inc., August 24, 2010.
VDR-327699, 2010, “DAS Data/Drilling and Grouting Logs – T-45B Location – OU 7-13/14 In Situ Grouting,” Rev. 0, Hayward Baker, Inc., August 24, 2010.
VDR-327704, 2010, “DAS Data/Drilling and Grouting Logs – T-49C Location – OU 7-13/14 In Situ Grouting,” Rev. 0, Hayward Baker, Inc., August 24, 2010.
VDR-327709, 2010, “DAS Data/Drilling and Grouting Logs – T-53B Location – OU 7-13/14 In Situ Grouting,” Rev. 0, Hayward Baker, Inc., August 24, 2010.
VDR-327716, 2010, “DAS Data/Drilling and Grouting Logs – T-56 Location – OU 7-13/14 In Situ Grouting,” Rev. 0, Hayward Baker, Inc., August 24, 2010.
VDR-328028, 2010, “DAS Data/Drilling and Grouting Logs – S-14 Location – OU 7-13/14 In Situ Grouting,” Rev. 0, Hayward Baker, Inc., August 24, 2010.
VDR-328033, 2010, “DAS Data/Drilling and Grouting Logs – T-39 Location – OU 7-13/14 In Situ Grouting,” Rev. 0, Hayward Baker, Inc., August 24, 2010.
Wegener, Nathan A. (Nathan.Wegener@icp.doe.gov), “Respirators,” email to, Adam Gerondale (firstname.lastname@example.org), Document ID 3314145, April 20, 2010.