Streamlined Approach for Environmental Restoration Plan for Corrective Action Unit 116: Area 25 Test Cell C Facility, Nevada Test Site, Nevada, Revision 1

This Streamlined Approach for Environmental Restoration (SAFER) Plan identifies the activities required for the closure of Corrective Action Unit (CAU) 116, Area 25 Test Cell C Facility. The Test Cell C (TCC) Facility is located in Area 25 of the Nevada Test Site (NTS) approximately 25 miles northwest of Mercury, Nevada (Figure 1). CAU 116 is currently listed in Appendix III of the Federal Facility Agreement and Consent Order (FFACO) of 1996 (as amended February 2008) and consists of two Corrective Action Sites (CASs): (1) CAS 25-23-20, Nuclear Furnace Piping; and (2) CAS 25-41-05, Test Cell C Facility. CAS 25-41-05 is described in the FFACO as the TCC Facility but actually includes Building 3210 and attached concrete shield wall only. CAU 116 will be closed by demolishing Building 3210, the attached concrete shield wall, and the nuclear furnace piping. In addition, as a best management practice (BMP), Building 3211 (moveable shed) will be demolished due to its close proximity to Building 3210. This will aid in demolition and disposal operations. Radiological surveys will be performed on the demolition debris to determine the proper disposal pathway. As much of the demolition debris as space allows will be placed into the Building 3210 basement structure. After filling to capacity with demolition debris, the basement structure will be mounded or capped and closed with administrative controls. Prior to beginning demolition activities and according to an approved Sampling and Analysis Plan (SAP), representative sampling of surface areas that are known, suspected, or have the potential to contain hazardous constituents such as lead or polychlorinated biphenyls (PCBs) will be performed throughout all buildings and structures. Sections 2.3.2, 4.2.2.2, 4.2.2.3, 4.3, and 6.2.6.1 address the methodologies employed that assure the solid debris placed in the basement structure will not contain contaminants of concern (COCs) above hazardous waste levels. The anticipated post-closure-posting requirements for the mounded/capped basement structure, as well as for the entire CAU, are addressed in Section 4.2.10. The site contains radiologically impacted surfaces and hazardous materials. Based on review of the historical information for CAU 116 and recent site inspections, there is sufficient process knowledge to close CAU 116 using the SAFER process. CAUs that may be closed using the SAFER process have conceptual corrective actions that are clearly identified. Consequently, corrective action alternatives can be chosen prior to completing a corrective action investigation, given anticipated investigation results. The SAFER process combines elements of the data quality objective (DQO) process and the observational approach to plan and conduct closure activities. The DQOs are used to identify the problem and define the type and quality of data needed to complete the investigation phase of the SAFER process. The purpose of the investigation phase is to verify the adequacy of existing information used to determine the chosen corrective action. The observational approach provides a framework for managing uncertainty during the planning and decision-making phases of the project. The SAFER process allows for technical decisions to be made based on information gathered during site visits, interviews, meetings, research, and a consensus of opinion by the decontamination and decommissioning (D&D) team members. Any uncertainties are addressed by documented assumptions that are verified by sampling and analysis, data evaluation, onsite observations, and contingency plans, as necessary. Closure activities may proceed simultaneously with site characterization as sufficient data are gathered to confirm or disprove the assumptions made during selection of the corrective action. If, at any time during the closure process, new information is discovered that indicates that closure activities should be revised, closure activities will be reevaluated as appropriate. Based on a detailed review of historical documentation, there is sufficient process knowledge to close CAU 116 using the SAFER process. The COC have been determined and are discussed in Section 4.1