Streamlined Approach for Environmental Restoration Plan for Corrective Action Unit 121: Storage Tanks and Miscellaneous Sites, Nevada Test Site, Nevada

Technical Report · Fri Jun 01 00:00:00 EDT 2007

DOI:https://doi.org/10.2172/913588· OSTI ID:913588

NSTec Environmental Restoration

This Streamlined Approach for Environmental Restoration (SAFER) Plan identifies the activities required for the closure of Corrective Action Unit (CAU) 121, Storage Tanks and Miscellaneous Sites. CAU 121 is currently listed in Appendix III of the ''Federal Facility Agreement and Consent Order'' (FFACO, 1996) and consists of three Corrective Action Sites (CASs) located in Area 12 of the Nevada Test Site (NTS): CAS 12-01-01, Aboveground Storage Tank; CAS 12-01-02, Aboveground Storage Tank; and CAS 12-22-26, Drums; 2 AST's. CASs 12-01-01 and 12-01-02 are located to the west of the Area 12 Camp, and CAS 12-22-26 is located near the U-12g Tunnel, also known as G-tunnel, in Area 12 (Figure 1). The aboveground storage tanks (ASTs) present at CASs 12-01-01 and 12-01-02 will be removed and disposed of at an appropriate facility. Soil below the ASTs will be sampled to identify whether it has been impacted with chemicals or radioactivity above action levels. If impacted soil above action levels is present, the soil will be excavated and disposed of at an appropriate facility. The CAS 12-22-26 site is composed of two overlapping areas, one where drums had formerly been stored, and the other where an AST was used to dispense diesel for locomotives used at G-tunnel. This area is located above an underground radioactive materials area (URMA), and within an area that may have elevated background radioactivity because of containment breaches during nuclear tests and associated tunnel reentry operations. CAS 12-22-26 does not include the URMA or the elevated background radioactivity. An AST that had previously been used to store liquid magnesium chloride (MgCl) was properly disposed of several years ago, and releases from this tank are not an environmental concern. The diesel AST will be removed and disposed of at an appropriate facility. Soil at the former drum area and the diesel AST area will be sampled to identify whether it has been impacted by releases, from the drums or the AST, with chemicals or radioactivity above action levels. CAS 12-22-26 has different potential closure pathways that are dependent upon the concentrations and chemicals detected. If only petroleum hydrocarbons are detected above action levels, then the area will be use-restricted. It will not be excavated because of the more significant hazard of excavating within a URMA. Similarly, polychlorinated biphenyls (PCBs) will only be excavated for concentrations of 50 parts per million (ppm) or greater, if there are no other factors that require excavation. For PCBs at concentrations above 1 ppm, the area will be use-restricted as required by Title 40, Code of Federal Regulations (CFR) Part 761 for PCBs (CFR, 2006), in the ''Toxic Substances Control Act'' (TSCA). Other chemicals at concentrations above the final action levels (FALs) will be excavated. If radioactivity is above action levels, then the soil will be excavated only to a depth of 1 foot (ft) below ground surface (bgs) and replaced with clean fill. This action is intended to remove the ''hot spot'' on the surface caused by leakage from a drum, and not to remediate the URMA.

• Research Organization: National Security Technologies, LLC (NSTec), Mercury, NV (United States)
• Sponsoring Organization: USDOE
• DOE Contract Number: DE-AC52-06NA25946
• OSTI ID: 913588
• Report Number(s): DOE/NV-1208; DOE/NV/25646-208; TRN: US0800779
• Country of Publication: United States
• Language: English

Related Subjects

12 MANAGEMENT OF RADIOACTIVE AND NON-RADIOACTIVE WASTES FROM NUCLEAR FACILITIES
CLOSURES
CONTAINMENT
EXCAVATION
HYDROCARBONS
LOCOMOTIVES
MAGNESIUM CHLORIDES
NEVADA TEST SITE
PETROLEUM
POLYCHLORINATED BIPHENYLS
RADIOACTIVE MATERIALS
RADIOACTIVITY
REENTRY
REGULATIONS
SOILS
STORAGE
TANKS
Corrective Action Unit 121 SAFER Plan