SRS Cleanup Activities at Specific Areas / OUs
To learn more about cleanup progress at the U.S. Department of Energy (DOE) Savannah River Site (SRS), please see the descriptions of specific areas / operable units (OUs) listed below.
T-Area OU (OU-96)
T-Area is one of the fourteen SRS industrial areas. Built in the early 1950s, T-Area is located in the southwestern portion of SRS, just east of the Savannah River. Until 2003, T-Area was used for pilot-scale testing and evaluation to support the separation of uranium and plutonium produced from five on-site reactors. When the Cold War ended, T-Area was used to model and evaluate the process for converting the leftover waste generated from the separation processes into glass (vitrification) for storage at Yucca Mountain. The vitrification process is now used by the Defense Waste Processing Facility at SRS. Contaminants of concern at T-Area OU (OU-96) included uranium, thorium, mercury and volatile organic compounds associated with solvent use.
DOE/SRS completed the cleanup of T-Area surface units in 2006, marking the first Area Closure at SRS. DOE/SRS removed and disposed of two thousand cubic yards of highly contaminated soil off site, demolished all buildings and capped the 10-acre former industrial area with a geosynthetic engineered cover. The engineered cover system provides containment for contaminants from numerous T-Area facilities, including the former TNX-OU, and is similar to systems used at commercial landfills. With surface units addressed, cleanup efforts are now focused on remediating contaminants of concern in ground water, including chlorinated solvents (trichloroethylene and tetrchlorethylene) and mercury.
M-Area OU (OU-92)
The M-Area OU (OU-92) is located in the northwest portion of SRS and covers approximately 86 acres. (See map (PDF) (7 pp, 1.6MB).) Beginning in 1952, SRS produced nuclear materials. An important step in the production cycle was the manufacture of fuel and target assemblies in M-Area for the nuclear reactors. The manufacturing processes in M-Area consumed a large quantity of industrial cleaning solvents and water. Early practices included the discharge of spent solvents and water directly into the environment. The major production facilities used industrial cleaning processes and products such as trichloroethylene, tetrachloroethylene and trichloroethane, which were discarded to the M-Area Settling Basin via process sewer lines.
The M-Area OU consists of six waste units and 47 deactivation and decommissioning facilities located in M-Area. (See map showing additional information about M-Area OU. (PDF) (7 pp, 1.6MB)) Contaminants of concern at M-Area included uranium and trichloroethene. Waste unit cleanup included the removal of solvent sources of principal threat source material in the area. It is the second scheduled SRS industrial area to go through the Area Completion process. All deactivation and decommissioning work has been completed and the characterization field start for the remedial process began in 2006. Early cleanup activities (removal actions) to address contamination from M-Area deactivation and decommissioning slabs were taken in fiscal year 2007. The Proposed Plan for M-Area was issued in 2008. The final Record of Decision was signed in early fiscal year 2009 selecting passive soil vapor extraction relying upon BaroBall™ Soil vapor extraction wells as a core part of the remedy. An Explanation of Significant Difference was signed later in fiscal year 2009 to accelerate the cleanup using American Recovery and Reinvestment Act funding. All remedial work has been completed and work has now progressed to the monitoring phase with annual inspections and Five-Year Reviews.
P-Area OU (OU-94)
P-Area is the third SRS industrial area to go through the Area Completion process and the first Area Completion involving a hardened facility (reactor). The P-Area OU (OU-94) encompasses 125 acres and includes the reactor building and support facilities, administration and maintenance facilities, a cooling water and treatment system, a coal-burning power plant, waste disposal facilities, five miles of sewer lines and effluent discharges and the P-Area OU Ash Basin. Characterization of the likely contaminants of concern is complete. Contaminants of concern associated with reactor operations at P-Area include cesium, tritium, cobalt and trichloroethylene.
An Early Action Record of Decision (ROD) was issued in 2009 that designated in situ disposition for the P-Reactor and use of the P-Reactor as a consolidation and/or disposal area for P-Area wastes. Multiple public workshops were held and public comment and involvement was sought before moving forward with the cleanup of the first plutonium production reactor to be addressed under the Superfund law (CERCLA). An Explanation of Significant Differences was signed in early fiscal year 2010 to accelerate the cleanup using American Recovery and Reinvestment Act funding. The final ROD was signed in fiscal year 2011 and documented the selection of land use controls for P-Area.
R-Area OU (OU-95)
The R-Area OU is located in east-central SRS; it includes approximately 175 acres (including the R-Area Ash Basin, R-Area Groundwater and the R-Area Isolated Contamination Area) located primarily in the Lower Three Runs watershed. (See map (PDF). (7 pp, 1.6MB)) The northwestern portion of the R-Area OU is located in the Upper Three Runs watershed. The R-Area OU has a flat to gently rolling topography.
In 1953, R-Reactor began operations. In 1964, it was placed in shutdown status due to decreased demand for nuclear materials. The primary sources of radioactive contamination in R-Area are activation products, fission products and tritium, the majority of which were the consequence of R-Reactor operations. Currently, the R-Reactor Building (105-R) and other facilities within R-Area are undergoing deactivation in preparation for in situ decommissioning.
R-Area is the second reactor area to go through the Area Completion process. The R-Area OU (OU-95) encompasses multiple acres and includes the reactor building and support facilities, administration and maintenance facilities, a cooling water and treatment system, waste disposal facilities, five miles of sewer lines, and effluent discharges. Characterization of the likely constituents of concern is ongoing.
An Early Action Proposed Plan for R-Area was issued in fiscal year 2009. Due to the wide acceptance of the similar Record of Decision (ROD) for P-Area and its reactor, the Early Action Proposed Plan to address the R-Area reactor was expanded to include the final decision for the C-, K- and L-Area Reactors. As with P Area, the Early Action Proposed Plan for C, K, L and R Areas selected in situ decommissioning for the remaining reactor facilities at SRS. The reactor vessels and much of the reactor buildings will be grouted up and left in place when their operational mission is complete. An Early Action ROD for C-, K-, L- and R-Areas is currently scheduled for 2010, while the final R-Area ROD is currently scheduled for 2012. Contaminants of concern at R-Area are associated with reactor operations and include cesium, tritium, cobalt and trichloroethylene.
The Early Action ROD for the C-Area, K-Area, L- Area and R-Area Reactor Complexes was approved in December 2009, and documents the selected remedy for the R-Area Reactor Complex: in situ decommissioning with land use controls. In coordination with these remedial actions, several non-time critical removal actions will also be conducted. Non-time critical removal actions are documented in five Removal Reports and include the following subunits:
- The R-Area Reactor Building Complex. This subunit includes the R-Area Reactor Building, the Engine Houses (1R and 2R), the R-Area Reactor Vessel, the R-Area Reactor Disassembly Basin, the R-Area Reactor Emergency Basin, the Area on the North Side of Building 105-R, Laydown Area North of 105-R, Release from the Decontamination of R-Area Reactor Disassembly Basin, Combined Spills North of Building 105-R, and the Potential Release from the R-Area Disassembly Basin (105-R). The work to be done is in-situ decommissioning: below-grade contents of the Disassembly Basin will be grouted to stabilize the contaminants; above-grade structure of the Disassembly Basin will be demolished to grade level after removal of the Disassembly Basin water. This work is about 70 percent complete with various stages of work shown. (See photographs.)
- The R-Area Reactor Disassembly Basin. Most of the water in this subunit has been removed, but the remaining water and sludge will be grouted in place. This work is about 70 percent complete. (See photographs.)
- The R-Area PSL Combined Subunit. This subunit includes the R-Area PSLs as Abandoned, Process Water Storage Tank PSA, Purge Water Storage Basin, Cooling Water Effluent Sump Subunit, Septic Tank, outfalls, manholes, miscellaneous weirs and boxes, and sumps. This subunit includes about four miles of underground lines of various sizes and configurations that will be grouted in place. This removal work is about 80 percent complete.
- The R-Area Reactor Area Cask Car Railroad Tracks as Abandoned Subunit. The removal action at this subunit includes about 400 linear feet and 700 cubic yards of contaminated soil, railroad ties and rails. This work was completed in May 2010.
- The R-Area Ash Basin subunit. The removal action for this subunit includes consolidation of contaminated soils and the installation of a soil cover. This work is 90 percent complete. (See photographs.)
D-Area OU (OU-63)
D-Area is located in the southwest section of SRS, east of the Savannah River. The D-Area OU (OU-63) includes approximately 210 acres and is composed of surface units and source areas in D-Area that are potentially responsible for contaminating ground water. (See map (PDF). (7 pp, 1.6MB))
SRS produced special nuclear materials between 1952 and 1988. The reactors that were used to produce nuclear materials required heavy water (deuterium oxide) as a neutron moderator. Historically, heavy water was produced at D-Area at the D-Area Heavy Water Facility (i.e., the Bubble Tower Subunit). D-Area also contained the Heavy Water Rework Facility
The D-Area OU subunits include both deactivation and decommissioning facilities and active facilities associated with the operation of the 484-D Powerhouse. (See map showing D-Area OU subunits (PDF). (7 pp, 1.6MB)) The following subunits have been established based on their geographical proximity within D-Area:
- Bubble Tower Subunit.
- Moderator Processing Subunit.
- Powerhouse Subunit.
- Miscellaneous Units.
- D-Area Inactive Process Sewer Lines.
- Electrical Transformers.
- Miscellaneous Buildings.
Much of D-Area contamination has been addressed through earlier Records of Decision (RODs). Multiple removal actions are planned for D-Area during 2011-2012 to address tritium contamination and contamination associated with the coal storage and disposal piles in the area.
The Bubble Tower Subunit is located in the northern area of the D-Area OU and is approximately 95 acres in size. Tetrachloroethylene was identified as a contaminant migration constituent of concern. The ongoing removal action at the Bubble Tower Subunit is addressing volatile organic compound (VOC)-contaminated soil. Soil vapor extraction (SVE) with institutional controls has been selected as the preferred removal action. The SVE system will use MicroblowerTM-equipped SVE wells at 11 locations. The MicroblowerTM system removes VOCs from the soil by applying a vacuum to the subsurface to remove the vapor-phase contaminants. The scope of the removal action involves an approximate area of 10,890 square feet, a depth of 10 feet, and an in situ volume of 4,033 cubic yards. The MicroblowerTM system will likely be operational for four years to achieve the remedial goals. Institutional controls will include warning signs, deed restrictions and short-term and long-term monitoring to determine the effectiveness of the removal action. The removal action at the Bubble Tower subunit is scheduled to be completed by May 2011. (See photographs showing various stages of field preparation of the wells.)
The removal action for the Moderator Processing Subunit, which began as a treatability study to address the tritium in soil and concrete, is now underway. Tritium was identified as a contaminant migration constituent of concern embedded in the concrete and soils. Specially designed and fabricated treatment cells will heat a mixture of concrete and soils to ranges of 1,000 to 1,500 degrees Fahrenheit. The temperature will be maintained until the tritium concentrations meet remedial goals. The removal action is scheduled to be completed by September 2011. (See photographs.)
The scheduled removal action for the Powerhouse Subunit will address polychlorinated biphenyls- and pesticide-contaminated sediments from the D-006 Outfall and arsenic-contaminated soil from the 484-10D Waste Oil Facility will be placed into the northern section after it has been dewatered. A soil cover consistent with Class 2 landfill requirements will then be constructed over the northern section.
An Interim ROD for D Area is scheduled for 2011. The Interim ROD will document the early actions at:
- The Bubble Tower subunit.
- The Coal Pile Runoff Basin and Asbestos Pit.
- Inactive Process Sewer Lines.
- Electrical Transformers and Miscellaneous Buildings.
E Area Low-Level Waste Facility (OU-86)
The E-Area Low-Level Waste Facility (LLWF) was not originally part of the 1993 Federal Facilities Agreement (FFA) because DOE operates the facility under the authority of the Atomic Energy Act. In 1996, the E-Area Slit Trench Disposal Units were approved to receive CERCLA waste per the CERCLA Off-Site Rule (40 Code of Federal Regulations § 300.440). However, in February 2007, EPA sent a Notice of Unacceptability to DOE indicating that the E-Area Slit Trench Disposal Units were unacceptable for the receipt of Superfund (CERCLA) waste. In July 2007, representatives from the DOE, EPA and South Carolina Department of Health and Environmental Control (SCDHEC) met and resolved issues concerning the disposal of Superfund waste in the E-Area LLWF Slit Trench Disposal Units. As part of this agreement, DOE placed the entire E-Area LLWF on the FFA, thus allowing the disposal units to receive Superfund waste.
In fiscal year 2010, an Interim Record of Decision (ROD) was issued which increased the protection of human health and the environment by adding additional water infiltration barriers to two of the trenches. Later in fiscal year 2010, an Explanation of Significant Differences to the Interim ROD was signed, adding three more of the trenches to the remedy in the Interim ROD. The remedial action started in May 2010. (See photographs of E-Area.)
High Level Waste Tanks: F-Area Tank Farm (OU-23) and H-Area Tank Farm (OU-89)
The High Level Waste Tanks at SRS are considered by DOE and South Carolina Department of Health and Environmental Control (SCDHEC) to be the greatest human health risk in South Carolina. EPA, DOE and SCDHEC resolved a dispute concerning the closure of Tanks 18 and 19 in fiscal year 2007. As a result, a new tank schedule was established. SRS now has new milestones for tank modeling documents, Bulk Waste Removal Completions and eventual tank closures while maintaining the original closure date of 2022 for the single walled non-compliant tanks. In order to treat the waste from the tanks, SRS is building a salt waste processing facility. This facility will separate low level waste, which represents most of the volume of the waste, from the high level waste, which contains most of the radioactive materials. The low level waste will be grouted on site at SRS in the Salt Stone Facility. The high level waste will be sent to the existing Defense Waste Processing Plant at SRS to be entombed in glass by vitrification and stored in stainless steel canisters at SRS until the opening of a federal repository for high level waste.
DOE/SRS has already met the first milestone by submitting a draft Performance Assessment for the F-Area Tank Farm. The draft Performance Assessment for the H-Area Tank Farm will be submitted to EPA for review in March 2011. The next goal was to remove 75 percent of remaining waste in Tanks 18 and 19 before spring 2009. Due to technical difficulties, the goal date was moved to June 2009. DOE/SRS met the goal and is proceeding with the waste determination effort for Tanks 18 and 19, which will lead to a closure module for the two tanks and, ultimately, a waste determination and tank closure.
Chemical, Metals and Pesticides (CMP) Pits OU (OU-24)
The CMP Pits OU is located in the central portion of the SRS site, about a mile north of L Area. The unit is located in the Pen Branch watershed, southeast of Pen Branch. (See map (PDF). (7 pp, 1.6MB)) The nearest plant boundary is approximately 12 miles from the center of the OU. The CMP Pits were approximately seven acres in size and consisted of seven unlined pits, placed in two rows, which occupied the top of a knoll. The pits received non-radioactive waste between 1971 and 1979. During that time, chemicals, metals, pesticides and fluorescent lighting ballasts containing polychlorinated biphenyls were disposed of in the pits. In 1984, drums and other contaminated media were excavated from the pits and backfilled, and an infiltration cover was installed. It was later discovered that solvents remained in the soils below the pits, and these solvents had to be removed to prevent contamination from reaching the ground water.
Starting in 2001, soil vapor extraction removed 9,300 pounds of solvents. In 2006, a remedial method called Electrical Resistance Heating (ERH) was applied to help address the remaining small pockets of contamination. In ERH, electrodes heat the soil to 200 degrees Fahrenheit, transforming the liquid solvents into a gas phase. The contaminants are then removed through soil vapor extraction. The rate of removal has proven to be over 80 percent faster than soil vapor extraction alone, and the system facilitates capture of solvent contamination, not only expediting cleanup, but also preventing further ground water contamination.
In 13 months, over 3,500 pounds of contaminants were removed using ERH. The ERH facility has since been dismantled. Monitored natural attenuation is being used to ensure that natural cleanup processes are proceeding as anticipated and reporting is conducted annually. Ground water testing is ongoing.
Former Gunsite 218 (OU-80) / Former Gunsite 012 (OU-78)
Former Gunsite 218 (OU-80) was a satellite gunsite used to stage anti-aircraft guns in the 1950s. In 2010, site investigations and risk evaluations were completed. The site does not pose an unacceptable risk to human health or the environment, and no remedial action is warranted. Former Gunsite 012 (OU-78) was a central gunsite, consisting of both gun emplacements for antiaircraft guns and support facilities such as barracks, a motor pool and administrative buildings. Site investigations and risk evaluations were completed in 2010. Due to the presence of polyaromatic hydrocarbons and antimony in soils, use of the site will be restricted to protect human health. The site is safe to use for industrial purposes; unrestricted future use, such as residential use, is prohibited.
A–Area Ash Pile and Coal Pile Runoff Basin (OU-62)
The A–Area Ash Pile and Coal Pile Runoff Basin (OU-62) consists of the coal pile runoff basin and ash pile associated with the A-Area coal burning power plant. Metals and radionuclide levels are elevated in the basin and ash pile. The remedial investigation and baseline risk assessment will be completed in 2011. Following the remedial investigation and baseline risk assessment, a decision will be made regarding whether a remedy is required.
Early Construction and Operational Disposal Sites (ECODS) B-3 and B-5 (B-Area)
The ECODS B-3 and B-5 sites are unlined pits that were used from 1951 to 1955 for disposal of waste material associated with the construction of B-Area at SRS. Construction waste was buried in shallow, elongated trenches. Some sections of the trenches were also used as burn pits for combustible waste disposal. ECODS B-3 is approximately 164,160 cubic feet (4648 cubic meters) in size. ECODS B-5 is approximately 13,662 cubic feet (387 cubic meters) in size.
DOE submitted a Removal Site Evaluation Report/Engineering Evaluation/Cost Analysis (PDF) (96 pp, 7.5MB) to EPA and South Carolina Department of Health and Environmental Control (SCDHEC) for review and approval in February 2010 as part of the cleanup work funded by the American Recovery and Reinvestment Act. No principal threat source material was identified at these sites. However, the Human Health Risk Assessment for ECODS B-3 and B-5 identified arsenic, semi-volatile organic compounds and seven pesticides as refined constituents of concern. Based upon evaluations of other ECODS at SRS, friable asbestos may also be present. In summer 2010, DOE/SRS began excavating waste material from ECODS B-3 and B-5. Construction waste and impacted soil were removed and sent to a Superfund (CERCLA) Off-Site Rule Approved Landfill for disposal. DOE/SRS plans to meet residential cleanup goals for the sites and make them available for unrestricted future uses. DOE/SRS also performed confirmatory sampling of the area to ensure that residual wastes do not pose an unacceptable risk to human health and the environment. DOE/SRS will provide this data to EPA and SCDHECfor approval.
Early Construction and Operational Disposal Sites (ECODS) L-1, N-2, P-2, R-1A, -1B and -1C
The ECODS L-1, N-2, P-2, R-1A, -1B and -1C are shallow land disposal pits used between 1951 and 1955 to dispose of material associated with construction of SRS facilities. Construction waste was buried in shallow, elongated trenches, with some trenches also used as burn pits for combustible waste disposal. While these sites are located in L-, N-, P-, and R-Areas around SRS, they were addressed together due to the similar contaminants in these areas. Investigation of the sites revealed the presence of polycyclic aromatic hydrocarbons, polychlorinated biphenyls, volatile organic compounds, metals and potentially friable asbestos. DOE/SRS selected land use controls to restrict land uses to reduce potential future risk to industrial workers and future residents and submitted a Record of Decision in March 2010, which was approved by EPA and South Carolina Department of Health and Environmental Control.
Heavy Water Components Test Reactor (B-Area)
The Heavy Water Components Test Reactor (HWCTR) facility is located on approximately two acres in the B-Area of SRS. The HWCTR was a pressurized heavy water test reactor designed to test candidate fuel designs for heavy water power reactors. The HWCTR facility operated from 1962 to 1964, when the facility was placed in a standby condition.
DOE/SRS submitted a Removal Site Evaluation Report/Engineering Evaluation/Cost Analysis (PDF) (2 pp, 112K) to EPA and South Carolina Department of Health and Environmental Control for review and approval in February 2010 as part of cleanup activities funded by the American Recovery and Reinvestment Act. The purpose of the proposed removal action is to protect future industrial workers from exposure to radionuclides and hazardous constituents in the reactor vessel, steam generators and associated equipment in the HWCTR, and to prevent potential migration to ground water. In 2009, the total amount of radioactivity in the facility was estimated to be about 2,100 curies, most of it associated with the reactor vessel. DOE/SRS is currently decommissioning the facility in place and will remove the reactor vessel, steam generators and all above grade components except the transfer fuel coffin. This effort is scheduled to be complete in fiscal year 2012. Land use controls and ongoing surveillance and maintenance activities will be implemented upon completion as well.
C-Area is located in the west-central portion of SRS and includes the area surrounding the C-Reactor Building (105-C). The Reactor Building, which operated from 1955 to 1985, was placed in cold standby in 1987 and later shutdown. The C-Reactor Building is still used as a central decontamination facility for radiologically contaminated equipment, storage of tritiated-moderator water in tanks, and for temporary storage of Cold War historical artifacts. The subunits and structures that comprise C-Area are decommissioning and deactivation facilities, C-Area OU subunits and the C-Reactor Groundwater OU.
An Early Action Record of Decision (ROD) was signed in December 2009 for the C-, K-, L-, and R-Reactor Complexes. The ROD selected in situ decommissioning with land use controls as the preferred remedy. DOE is evaluating the potential for the C-Area Reactor Building to serve as a museum. The C-Area OU subunits are located adjacent to or in the vicinity of the C-Reactor Building (105-C) Complex and include:
- C-Area Reactor Area Cask Car Railroad Tracks as Abandoned.
- Potential Release from C-Area Reactor Cooling Water System (Bldg 186/190-C).
- Contaminated Maintenance Facility (Bldg 717-C) (Hot Shop slab remnant).
- Retention Basin for 100-C Containment (Bldg 904-89G).
- Potential Release from C-Area Disassembly Basin.
- C-Area Process Sewer Lines as Abandoned.
- Outfalls C-01 and C-03.
- Fuel Unloading Facilities Power – Area Supv (Bldg 108-3C).
- Early Construction Operation and Disposal sites C-1.
DOE/SRS plans to submit a Removal Site Evaluation Report/Engineering Evaluation/Cost Analysis for each subunit in the C-Area OU and ultimately prepare a Record of Decision for the C-Area OU.
105-C Disassembly Basin (C-Area)
The 105-C Disassembly Basin (DB) is part of the 105-C Reactor Building located in C-Area. When the Reactor was operating, irradiated targets and fuel were transferred from the reactor vessel to the DB, which resulted in tritium in the DB water and sediment. Other fission products came from underwater cutting operations and failed fuel elements stored in the basin. Cesium-137(+D) and Strontium-90 isotopes are also present in the DB water and sediments and are contaminants of concern.
DOE/SRS estimates the DB contains approximately 2.7 million gallons of water in 2010 and plans to dewater the DB, sand filters and settler tanks and fill the DB with grout. Approximately 500,000 gallons of tritiated water stored in the emergency cooling system tank in the 904-89G retention basin will also be evaporated. In October 2010, DOE/SRS submitted a Removal Site Evaluation Report/Engineering Evaluation/Cost Analysis which selected forced evaporation of these waters and grouting of the DB as the proposed remedy for these structures. This proposal is currently being evaluated b EPA and South Carolina Department of Health and Environmental Control.
C- Area Cask Car Railroad Tracks as Abandoned
The C-Area Cask Car Railroad Tracks as Abandoned is an area west of the C-Reactor. During operation of the C-Reactor, radiological material from the reactor was transferred into metal casks and later loaded onto railroad cars. The outside surfaces of the casks would occasionally become contaminated with radiological compounds while being packed. When the cask cars were exposed to rain, radiological materials were washed from the cask cars onto the railroad tracks below. All existing railroad tracks within the C-Area perimeter fence are addressed in this subunit. A study performed in 2001 estimates that approximately 23 linear feet of railbed gravel and soil are contaminated with Cesium-137 above 10 picocuries per gram. Remaining railroad tracks may also be contaminated and will be sampled in fiscal year 2011.
DOE/SRS is currently preparing a Removal Site Evaluation Report/Engineering Evaluation/Cost Analysis for this subunit which states that railroad ties, gravel and soil exceeding 10 picocuries per gram will be excavated, removed and disposed of in an appropriate facility in fiscal year 2011. These materials will be replaced to maintain the facility’s potential for future use as a museum.
Small Arms Training Area
The Small Arms Training Area (SATA) at SRS has operated since 1951 as a practice and gun firing range facility for small arms weapon training of SRS security personnel. The SATA facility comprises three small arms ranges, storage buildings for supplies, a weapon cleaning building and a control building. An approximately 370-foot-long earthen “berm” at the facility has been used as a backstop for bullets shot during target practice. The berm soils have accumulated a large amount of spent lead bullets which have lead soil concentrations that exceed EPA residential and industrial worker regional screening levels.
EPA and SCDHEC approved the DOE/SRS Removal Site Evaluation Report/Engineering Evaluation/Cost Analysis (PDF) (2 pp, 112K) in May 2010, which detailed the removal and disposal of the contaminated soil. The excavated materials will be sent to an approved off-site disposal facility. Confirmation sampling will ensure that cleanup levels will at minimum meet industrial cleanup standards.
L-Area Southern Groundwater OU
The L Area is located in the south-central portion of SRS. The L-Area Reactor operated from 1954 to 1968 and from 1984 to 1988. L Lake was constructed in 1985 as a cooling pond for the L-Reactor and contains seven billion gallons of water. The L-Area Southern Groundwater OU encompasses all the ground water from the L-Area ground water divide south to L Lake. Past activities at the remediated/depleted source units have resulted in ground water contamination beneath L-Area Southern Groundwater OU. Contaminants include plumes of tritium, tetrachloroethylene and trichloroethylene.
A Record of Decision (PDF) (91 pp, 2.8MB) was signed in 2007 to address these three plumes south of the L-Area Reactor. The selected remedy is monitored natural attenuation with institutional controls. DOE is required to submit biannual monitoring under the Effectiveness Monitoring Plan to EPA and SCDHEC for review and approval. The first monitoring results were provided in 2010 for 2008-2009. This document provides monitoring well data and information on the installation of new monitoring wells. The monitoring well network data show that the tritium, TCE and PCE contamination levels are decreasing as expected and none of the contaminants were detected at the boundary of the OU.
L-Area Northern Groundwater OU
The L-Area Northern Groundwater OU is separated by the L-Area Southern Groundwater OU by a ground water divide located along the northern edge of L-Area. The L-Area Northern Groundwater OU is currently being investigated to determine the nature and extent of contamination and identify any potential threats to human health and the environment. DOE/SRS submitted a Statement of Basis/Proposed Plan for the L-Area Northern Groundwater OU in March 2010 which recommended no action as there were no constituents of concern which posed a risk to human health and the environment. EPA and South Carolina Department of Health and Environmental Control reviewed and approved this plan in 2010. DOE/SRS plans to submit a draft No Action Record of Decision to the agencies in 2011.
C-Area, K-Area and L-Area Reactor Complexes (OU-79, OU-90 and OU-91)
The C-Area, K-Area, and L-Area Reactor Complexes operated in support of SRS’s primary mission to produce tritium, plutonium and other nuclear materials for the nation’s defense programs. Although the C-Area, K-Area and L-Area Reactor Complexes are no longer producing nuclear material, the complexes have continuing missions associated with nuclear material storage.
Due to the wide acceptance of the similar Record of Decision (ROD) for P-Area and its reactor, the Early Action Proposed Plan to address the reactor in R-Area was expanded to include the final decision for the C-Area, K-Area, and L-Area-Reactors. As with P-Area, the Early Action Proposed Plan for the C-Area, K-Area, and L-Area Reactors selected in situ decommissioning with land use controls for the remaining reactor facilities at SRS. The in situ decommissioning end state will not be implemented until all missions have ceased at these Reactor Complexes.
The in situ decommissioning remedy will include the following activities:
- Maintaining the structural integrity of the above-ground portions of each facility for at least a period of 200 years, preventing exposure to receptors from residual short-lived radioisotopes in building structure and preventing tritium migration due to infiltration.
- Stabilizing contaminants in place as necessary to prevent unacceptable release to the environment.
- Sealing associated building to eliminate routes of human and animal intruder access, thereby eliminating unacceptable exposure to radiological or hazardous contamination.
Land use controls included as part of the selected remedy are currently in place as part of ongoing operations and include:
- Access controls to prevent unacceptable exposure to on-site workers, work control, worker training.
- Worker briefing of health and safety requirements.
- Physical controls and warning signs.
- Access controls to prevent unacceptable exposure to trespassers, which describes the security procedures and equipment, 24-hour surveillance system, artificial or natural barriers, control entry systems, and warning signs in place at the SRS boundary.
An Early Action ROD for the C-Area, K-Area, and L-Area Reactors is currently in place.