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Title: Corrective Action Investigation Plan for Corrective Action Unit 99: Rainier Mesa/Shoshone Mountain, Nevada Test Site, Nevada, Rev. No. 0

Corrective Action Investigation Plan for Corrective Action Unit 99: Rainier Mesa/Shoshone Mountain, Nevada Test Site, Nevada, Rev. No. 0 This Corrective Action Investigation Plan (CAIP) was developed for Corrective Action Unit (CAU) 99, Rainier Mesa/Shoshone Mountain. The CAIP is a requirement of the ''Federal Facility Agreement and Consent Order'' (FFACO) agreed to by the State of Nevada, the U.S. Department of Energy (DOE), and the U.S. Department of Defense (DoD) (FFACO, 1996). The FFACO addresses environmental restoration activities at U.S. Department of Energy, National Nuclear Security Administration Nevada Site Office (NNSA/NSO) facilities and sites including the underground testing area(s) of the Nevada Test Site (NTS). This CAIP describes the investigation activities currently planned for the Rainier Mesa/Shoshone Mountain CAU. These activities are consistent with the current Underground Test Area (UGTA) Project strategy described in Section 3.0 of Appendix VI, Revision No. 1 (December 7, 2000) of the FFACO (1996) and summarized in Section 2.1.2 of this plan. The Rainier Mesa/Shoshone Mountain CAU extends over several areas of the NTS (Figure 1-1) and includes former underground nuclear testing locations in Areas 12 and 16. The area referred to as ''Rainier Mesa'' includes the geographical area of Rainier Mesa proper and the contiguous Aqueduct Mesa. Figure 1-2 shows the locations of the tests (within tunnel complexes) conducted at Rainier Mesa. Shoshone more » Mountain is located approximately 20 kilometers (km) south of Rainier Mesa, but is included within the same CAU due to similarities in their geologic setting and in the nature and types of nuclear tests conducted. Figure 1-3 shows the locations of the tests conducted at Shoshone Mountain. The Rainier Mesa/Shoshone Mountain CAU falls within the larger-scale Rainier Mesa/Shoshone Mountain Investigation Area, which also includes the northwest section of the Yucca Flat CAU as shown in Figure 1-1. Rainier Mesa and Shoshone Mountain lie adjacent to the Timber Mountain Caldera Complex and are composed of volcanic rocks that erupted from the caldera as well as from more distant sources. This has resulted in a layered volcanic stratigraphy composed of thick deposits of welded and nonwelded ash-flow tuff and lava flows. These deposits are proximal to the source caldera and are interstratified with the more distal facies of fallout tephra and bedded reworked tuff from more distant sources. In each area, a similar volcanic sequence was deposited upon Paleozoic carbonate and siliciclastic rocks that are disrupted by various thrust faults, normal faults, and strike-slip faults. In both Rainier Mesa (km) to the southwest, and Tippipah Spring, 4 km to the north, and the tunnel complex is dry. Particle-tracking simulations performed during the value of information analysis (VOIA) (SNJV, 2004b) indicate that most of the regional groundwater that underlies the test locations at Rainier Mesa and Shoshone Mountain eventually follows similar and parallel paths and ultimately discharges in Death Valley and the Amargosa Desert. Particle-tracking simulations conducted for the regional groundwater flow and risk assessment indicated that contamination from Rainier Mesa and Shoshone Mountain were unlikely to leave the NTS during the 1,000-year period of interest (DOE/NV, 1997a). It is anticipated that CAU-scale modeling will modify these results somewhat, but it is not expected to radically alter the outcome of these previous particle-tracking simulations within the 1,000-year period of interest. The Rainier Mesa/Shoshone Mountain CAIP describes the corrective action investigation (CAI) to be conducted at the Rainier Mesa/Shoshone Mountain CAU to evaluate the extent of contamination in groundwater due to the underground nuclear testing. The CAI will be conducted by the UGTA Project, which is part of the NNSA/NSO Environmental Restoration Project (ERP). The purpose and scope of the CAI are presented in this section, followed by a summary of the entire document. « less
Authors:
Publication Date:
OSTI Identifier:838783
Report Number(s):DOE/NV--1031
TRN: US0501514
DOE Contract Number:AC-5203NA99205
Resource Type:Technical Report
Data Type:
Resource Relation:Other Information: PBD: 1 Dec 2004
Research Org:Stoller-Navarro Joint Venture (US)
Sponsoring Org:US Department of Energy (US)
Country of Publication:United States
Language:English
Subject: 54 ENVIRONMENTAL SCIENCES; NEVADA TEST SITE; RISK ASSESSMENT; STRATIGRAPHY; SITE CHARACTERIZATION; UNDERGROUND EXPLOSIONS; NUCLEAR EXPLOSIONS; PLANNING; REMEDIAL ACTION