Corrective Action Decision Document/Closure Report for Corrective Action Unit 552: Area 12 Muckpile and Ponds, Nevada Test Site, Nevada, Rev. No.: 0 with Errata Sheet

摘要

This Corrective Action Decision Document (CADD)/Closure Report (CR) has been prepared for Corrective Action Unit (CAU) 552, Area 12 Muckpile and Ponds, Nevada Test Site (NTS), Nevada. The corrective actions proposed in this document are in accordance with the ''Federal Facility Agreement and Consent Order'' (FFACO) that was agreed to by the State of Nevada, U.S. Department of Energy (DOE), and the U.S. Department of Defense (FFACO, 1996). The NTS is approximately 65 miles (mi) northwest of Las Vegas, Nevada (Figure 1-1). Corrective Action Unit 552 is comprised of the corrective action site (CAS) that is shown on Figure 1-2 and listed below: 12-23-05, Ponds. The ponds were originally constructed to catch runoff from the muckpile. As the muckpile continued to be extended to the north and to the east, it became impossible to ensure that all of the runoff from the muckpile was funneled into the pond. Some of the runoff from the muckpile continues to be caught in the upper pond, but portions of the muckpile have eroded, diverting much of the runoff away from the ponds. Regarding the other ponds, there is no evidence that any of the overflow ponds ever received runoff from overflow of the upper pond. The muckpile was removed from CAU 552 because an active leachfield exists within the muckpile and there are current activities at G-Tunnel. A detailed discussion of the history of this CAU is presented in the ''Corrective Action Investigation Plan (CAIP) for Corrective Action Unit 552: Area 12 Muckpile and Ponds, Nevada Test Site, Nevada'', Rev. 1 (NNSA/NSO, 2005). Corrective Action Unit 552, Area 12 Muckpile and Ponds, consists of one site located in the southern portion of Area 12. Corrective Action Site 12-23-05 consists of dry ponds adjacent to the G-Tunnel muckpile. The ponds were used to contain effluent from the G-Tunnel. The purpose of this CADD/CR is to provide justification for the closure of CAU 552 with no further corrective action. This justification is based on process knowledge and the results of the investigative activities conducted in accordance with the CAIP (NNSA/NSO, 2005) and the corresponding Records of Technical Change (ROTCs). The CAIP provides information relating to the history, planning, and scope of the investigation; therefore, this information will not be repeated in this CADD/CR.