Nevada DOE/NV--1031 Environmental Restoration Project Corrective Action Investigation Plan for Corrective Action Unit 99: Rainier Mesa/Shoshone Mountain, Nevada Test Site, Nevada Controlled Copy No.: Revision No.: 0 December 2004 Approved for public release; further dissemination unlimited. Environmental Restoration Division U.S. Department of Energy National Nuclear Security Administration Nevada Site Office Available for sale to the public from: U.S. Department of Commerce National Technical Information Service 5285 Port Royal Road Springfield, VA 22161 Phone: 800.553.6847 Fax: 703.605.6900 Email: [email protected] Online ordering: http://www.ntis.gov/ordering.htm Available electronically at http://www.osti.gov/bridge Available for a processing fee to U.S. Department of Energy and its contractors, in paper, from: U.S. Department of Energy Office of Scientific and Technical Information P.O. Box 62 Oak Ridge, TN 37831-0062 Phone: 865.576.8401 Fax: 865.576.5728 Email: [email protected] Reference herein to any specific commercial product, process, or service by trade name, trademark, manufacturer, or otherwise, does not necessarily constitute or imply its endorsement, recommendation, or favoring by the United States Government or any agency thereof or its contractors or subcontractors. Printed on recycled paper DOE/NV--1031 CORRECTIVE ACTION INVESTIGATION PLAN FOR CORRECTIVE ACTION UNIT 99: RAINIER MESA/SHOSHONE MOUNTAIN NEVADA TEST SITE, NEVADA U.S. Department of Energy National Nuclear Security Administration Nevada Site Office Las Vegas, Nevada Controlled Copy No.: Revision No.: 0 December 2004 Approved for public release; further dissemination unlimited. CORRECTIVE ACTION INVESTIGATION PLAN FOR CORRECTIVE ACTION UNIT 99: RAINIER MESA/SHOSHONE MOUNTAIN NEVADA TEST SITE, NEVADA Approved by: Date: Bill Wilborn, Acting Project Manager Underground Test Area Project Approved by: Date: Robert M. Bangerter, Acting Division Director Environmental Restoration Division CAU 99 CAIP Section: Contents Revision: 0 Date: December 2004 Page i of xx Table of Contents List of Figures. vi List of Plates . ix List of Tables. x List of Symbols for Elements and Compounds . xiii List of Stratigraphic Unit Abbreviations and Symbols. xv List of Acronyms and Abbreviations . xvi 1.0 Introduction. 1 1.1 Purpose . 5 1.2 Scope. 6 1.3 Summary of the CAIP. 7 1.3.1 Overview of Technical Elements of the CAIP. 7 1.3.1.1 Characterization Activities . 9 1.3.1.2 Assessment of CAU-Related Data . 9 1.3.1.3 Development of Numerical Groundwater Flow and Transport Model . 9 1.3.1.4 Verification of Numerical Groundwater Flow and Contaminant Transport Model . 10 1.3.1.5 Prediction of Contaminant Boundary . 10 1.3.1.6 CAI Documentation . 11 1.3.2 Document Organization . 11 2.0 Legal/Regulatory Requirements . 13 2.1 Federal Facility Agreement and Consent Order . 13 2.1.1 FFACO Requirements . 13 2.1.1.1 General Requirements . 13 2.1.1.2 Specific Requirements . 14 2.1.2 Corrective Action Strategy. 16 2.1.2.1 Description of Corrective Action Strategy . 16 2.1.2.1.1 General Definition of Contaminant Boundary . 17 2.1.2.1.2 Process Description . 17 2.1.2.2 Implementation of Corrective Action Strategy . 21 2.1.2.2.1 Specific Definition of the Contaminant Boundary . 21 2.1.2.2.2 Corrective Action Investigation . 21 2.1.2.2.3 Corrective Action Implementation and CAU Closure . 26 3.0 Description of Corrective Action Unit . 27 CAU 99 CAIP Section: Contents Revision: 0 Date: December 2004 Page ii of xx Table of Contents (Continued) 3.1 Investigative Background . 27 3.2 Operational History. 34 3.2.1 General . 34 3.2.2 Underground Nuclear Testing in the Rainier Mesa/Shoshone Mountain Area . 35 3.3 Corrective Action Sites. 37 3.4 Physical Setting. 38 3.4.1 Climate . 38 3.4.2 Topography. 46 3.4.3 Surface Water . 47 3.4.4 Geology . 48 3.4.4.1 Regional Geology . 48 3.4.4.2 Geology of the Rainier Mesa/Shoshone Mountain Vicinity . 54 3.4.5 Hydrology. 62 3.4.5.1 Regional Hydrogeology . 62 3.4.5.1.1 Hydrostratigraphy . 62 3.4.5.1.2 Groundwater . 66 3.4.5.2 Hydrology of the Investigation Area . 70 3.4.5.2.1 Hydrostratigraphy . 70 3.4.5.2.2 Groundwater Hydrology . 76 3.4.6 Groundwater Chemistry . 80 3.4.7 Major Ion Chemistry . 80 3.4.7.1 Regional Major Ion Chemistry . 81 3.4.7.2 Groundwater Chemistry of the Investigation Area . 84 3.4.7.3 Isotope Chemistry . 89 3.4.7.3.1 Hydrogen and Oxygen . 89 3.4.7.3.2 Carbon Isotopes . 92 3.4.8 Groundwater Radiochemistry. 94 3.4.8.1 Routine Radiological Environmental Monitoring Program . 94 3.4.8.2 Environmental Restoration Program . 104 3.4.8.3 Radionuclide Migration Program . 107 3.4.8.3.1 CHESHIRE (U20n and UE20n#1) . 108 3.4.8.3.2 CAMBRIC (RNM-1 & RNM-2S) . 109 3.4.9 Transport Parameters . 111 3.4.9.1 Porosity . 111 3.4.9.2 Dispersion . 115 3.4.9.3 Matrix Diffusion Coefficient . 117 3.4.9.4 Distribution Coefficients . 119 3.4.9.5 Colloidal Transport . 123 3.5 Contaminants . 125 CAU 99 CAIP Section: Contents Revision: 0 Date: December 2004 Page iii of xx Table of Contents (Continued) 3.5.1 Radioactive and Hazardous Substances Present. 125 3.5.1.1 Release Mechanisms . 125 3.5.2 Potential Contaminants for the CAI . 128 3.6 Conceptual Model of the CAU . 132 3.6.1 Release and Discharge . 135 3.6.1.1 Distribution and Release of Materials Related to Testing . 135 3.6.1.2 Discharge Mechanisms . 139 3.6.2 Migration of Contaminants. 140 3.6.2.1 Groundwater Flow Paths . 140 3.6.2.2 Contaminant Concentrations and Travel Times . 143 3.6.2.3 Contaminated Media . 144 3.6.2.4 Exposure Pathways . 145 3.6.3 Uncertainties. 145 3.7 Preliminary Corrective Action Levels . 146 4.0 Summary of Data Quality Objectives. 148 4.1 Data Quality Objectives Approach . ..