Corrective Action Investigation Plan for Corrective Action Unit 541: Small Boy Nevada National Security Site and Nevada Test and Training Range, Nevada with ROTC 1

Abstract

Corrective Action Unit (CAU) 541 is co-located on the boundary of Area 5 of the Nevada National Security Site and Range 65C of the Nevada Test and Training Range, approximately 65 miles northwest of Las Vegas, Nevada. CAU 541 is a grouping of sites where there has been a suspected release of contamination associated with nuclear testing. This document describes the planned investigation of CAU 541, which comprises the following corrective action sites (CASs): • 05-23-04, Atmospheric Tests (6) - BFa Site • 05-45-03, Atmospheric Test Site - Small Boy These sites are being investigated because existing information on the nature and extent of potential contamination is insufficient to evaluate and recommend corrective action alternatives (CAAs). Additional information will be obtained by conducting a corrective action investigation before evaluating CAAs and selecting the appropriate corrective action for each CAS. The results of the field investigation will support a defensible evaluation of viable CAAs that will be presented in the investigation report. The sites will be investigated based on the data quality objectives (DQOs) developed on April 1, 2014, by representatives of the Nevada Division of Environmental Protection; U.S. Air Force; and the U.S. Department of Energy (DOE), National Nuclear Security Administration Nevada Field Office. more » The DQO process was used to identify and define the type, amount, and quality of data needed to develop and evaluate appropriate corrective actions for CAU 541. The site investigation process also will be conducted in accordance with the Soils Activity Quality Assurance Plan, which establishes requirements, technical planning, and general quality practices to be applied to this activity. The potential contamination sources associated with CASs 05-23-04 and 05-45-03 are from nuclear testing activities conducted at the Atmospheric Tests (6) - BFa Site and Atmospheric Test Site - Small Boy sites. The presence and nature of contamination at CAU 541 will be evaluated based on information collected from field investigations. Radiological contamination will be evaluated based on a comparison of the total effective dose at sample locations to the dose-based final action level. The total effective dose will be calculated as the total of separate estimates of internal and external dose. Results from the analysis of soil samples will be used to calculate internal radiological dose. Thermoluminescent dosimeters placed at the center of each sample location will be used to measure external radiological dose. Appendix A provides a detailed discussion of the DQO methodology and the DQOs specific to each CAS. « less