Corrective Action Decision Document/Closure Report for Corrective Action Unit 545: Dumps, Waste Disposal Sites, and Buried Radioactive Materials Nevada Test Site, Nevada, Revision 0, with ROTC 1

Abstract

This Corrective Action Decision Document (CADD)/Closure Report (CR) has been prepared for Corrective Action Unit (CAU) 545, Dumps, Waste Disposal Sites, and Buried Radioactive Materials, in Areas 2, 3, 9, and 20 of the Nevada Test Site, Nevada, in accordance with the Federal Facility Agreement and Consent Order that was agreed to by the State of Nevada; U.S. Department of Energy (DOE), Environmental Management; U.S. Department of Defense; and DOE, Legacy Management (1996, as amended February 2008). Corrective Action Unit 545 is comprised of the following eight Corrective Action Sites (CASs): • 02-09-01, Mud Disposal Area • 03-08-03, Mud Disposal Site • 03-17-01, Waste Consolidation Site 3B • 03-23-02, Waste Disposal Site • 03-23-05, Europium Disposal Site • 03-99-14, Radioactive Material Disposal Area • 09-23-02, U-9y Drilling Mud Disposal Crater • 20-19-01, Waste Disposal Site While all eight CASs are addressed in this CADD/CR, sufficient information was available for the following three CASs; therefore, a field investigation was not conducted at these sites: • For CAS 03-08-03, though the potential for subsidence of the craters was judged to be extremely unlikely, the data quality objective (DQO) meeting participants agreed that sufficient information existed about disposal and releases at the sitemore » and that a corrective action of close in place with a use restriction is recommended. Sampling in the craters was not considered necessary. • For CAS 03-23-02, there were no potential releases of hazardous or radioactive contaminants identified. Therefore, the Corrective Action Investigation Plan for CAU 545 concluded that: “Sufficient information exists to conclude that this CAS does not exist as originally identified. Therefore, there is no environmental concern associated with CAS 03-23-02.” This CAS is closed with no further action. • For CAS 03-23-05, existing information about the two buried sources and lead pig was considered to be sufficient, and safety concerns existed about the stability of the crater component. Therefore, a corrective action of close in place with a use restriction is recommended, and sampling at the site was not considered necessary. The purpose of this CADD/CR is to provide justification and documentation to support the recommendation for closure of CAU 545 with no further corrective action. To achieve this, corrective action investigation (CAI) activities were performed from August 20 through November 02, 2007, as set forth in the CAU 545 Corrective Action Investigation Plan. The purpose of the CAI was to fulfill the following data needs as defined during the DQO process: • Determine whether contaminants of concern (COCs) are present. • If COCs are present, determine their nature and extent. • Provide sufficient information and data to complete appropriate corrective actions. The CAU 545 dataset from the investigation results was evaluated based on the data quality indicator parameters. This evaluation demonstrated the quality and acceptability of the dataset for use in fulfilling the DQO data needs. Analytes detected during the CAI were evaluated against final action levels established in this CADD/CR. The results of the CAI identified no COCs at the five CASs investigated in CAU 545. As a best management practice, repair of the fence enclosing CAS 03-08-03 has been completed. Therefore, the DOE, National Nuclear Security Administration Nevada Site Office provides the following recommendations: • Close in place COCs at CASs 03-08-03 and 03-23-05 with use restrictions. • No further corrective action for CAU 545. • No Corrective Action Plan. • Corrective Action Unit 545 should be moved from Appendix III to Appendix IV of the Federal Facility Agreement and Consent Order. • A Notice of Completion to the DOE, National Nuclear Security Administration Nevada Site Office is requested from the Nevada Division of Environmental Protection for closure of CAU 545.« less