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United States Office of Radiation and Indoor Air EPA 402-B-17-001 Environmental Protection National Analytical Radiation October 2019 Agency Environmental Laboratory High Resolution Gamma-Ray Spectrometry Analyses For Normal Operations and Radiological Incident Response EPA 402-B-17-001 October 2019 Revision 0 High Resolution Gamma-Ray Spectrometry Analyses for Normal Operations and Radiological Incident Response National Analytical Radiation Environmental Laboratory Office of Radiation and Indoor Air U.S. Environmental Protection Agency Montgomery, AL 36115 High Resolution Gamma Spectrometry Analyses For Normal Operations and Radiological Incident Response This report was prepared for the National Analytical Radiation Environmental Laboratory of the Office of Radiation and Indoor Air, United States Environmental Protection Agency. It was prepared by Environmental Management Support, Inc., of Silver Spring, Maryland, under contract EP-W-13-016, Task Order 014, managed by Daniel Askren. Mention of trade names or specific applications does not imply endorsement or acceptance by EPA. High Resolution Gamma Spectrometry Analyses For Normal Operations and Radiological Incident Response PREFACE This document is one of several initiatives by EPA’s Office of Radiation and Indoor Air (ORIA) designed to provide guidance to radioanalytical laboratories that will support EPA’s response and recovery actions following a radiological or nuclear incident. This guide examines the analysis of samples by gamma-ray spectrometry during normal operations and following a radiological incident. The guidance provided in this document for the screening and analysis of samples should assist those federal, state, and commercial radioanalytical laboratories that will be challenged with a large number of such samples when responding to a radiological or nuclear incident. This document is applicable to different types of events; a radiological transportation incident, a radiological dispersal device (RDD or “dirty bomb”), a release from an emergency condition at a nuclear power plant, or the detonation of an improvised nuclear device (IND), other potential radiological releases as well as normal laboratory operations. These samples will be contaminated with varying levels of radionuclides and will represent matrices of varied composition. Advance planning by national and regional response teams, as well as by radiological laboratories, will be critical to ensure uninterrupted throughput of large numbers of radioactive samples and the rapid turnaround and reporting of results that meet required data quality objectives associated with the protection of human health and the environment. EPA’s responsibilities, as outlined in the National Response Framework, Nuclear/Radiological Incident Annex, include response and recovery actions to detect and identify radioactive substances and to coordinate federal radiological monitoring and assessment activities. Detailed guidance on recommended radioanalytical practices can be found in the Multi-Agency Radiological Laboratory Analytical Protocols Manual (MARLAP), which provides detailed radioanalytical guidance for project planners, managers, and radioanalytical personnel based on project-specific requirements (www.epa.gov/radiation/marlap/links.html). Familiarity with Chapters 2, 3, 14, 15 and 18-20 of MARLAP will be of significant benefit to users of this guide. This document is one in a series designed to present radioanalytical laboratory personnel, Incident Commanders (and their designees), and other field response personnel with key laboratory operational considerations and likely radioanalytical requirements, decision paths, and default data quality and measurement quality objectives for analysis of samples taken after a radiological or nuclear incident. Documents currently completed include: Radiological Laboratory Sample Analysis Guide for Incidents of National Significance – Radionuclides in Water (EPA 402-R-07-007, January 2008) Radiological Laboratory Sample Analysis Guide for Incidents of National Significance – Radionuclides in Air (EPA 402-R-09-007, June 2009) Radiological Laboratory Sample Screening Analysis Guide for Incidents of National Significance (EPA 402-R-09-008, June 2009) Method Validation Guide for Qualifying Methods Used by Radiological Laboratories Participating in Incident Response Activities (EPA 402-R-09-006, June 2009) Guide for Laboratories – Identification, Preparation, and Implementation of Core Operations for Radiological or Nuclear Incident Response (EPA 402-R-10-002, June 2010) i High Resolution Gamma Spectrometry Analyses For Normal Operations and Radiological Incident Response A Performance-Based Approach to the Use of Swipe Samples in Response to a Radiological or Nuclear Incident (EPA 600-R-11-122, October 2011) Guide for Radiological Laboratories for the Control of Radioactive Contamination and Radiation Exposure (EPA 402-R-12-005, August 2012) Radiological Laboratory Sample Analysis Guide for Incident Response – Radionuclides in Soil (EPA 402-R-12-006, September 2012) Uses of Field and Laboratory Measurements During a Radiological or Nuclear Incident (EPA 402-R-12-007, August 2012) Comments on this document, or suggestions for future editions, should be addressed to: Dr. John Griggs U.S. Environmental Protection Agency Office of Radiation and Indoor Air National Analytical Radiation Environmental Laboratory 540 South Morris Avenue Montgomery, AL 36115-2601 (334) 270-3450 [email protected] ii High Resolution Gamma Spectrometry Analyses For Normal Operations and Radiological Incident Response ACKNOWLEDGMENTS This guide was developed by the National Analytical Radiation Environmental Laboratory (NAREL) of EPA’s ORIA. Dr. John Griggs was the project lead for this document. Technical support was provided by Dr. Robert Litman, Mr. Sherrod Maxwell, Dr. Daniel Montgomery, Dr. David McCurdy, Mr. Stan Morton and Mr. Robert Shannon of Environmental Management Support, Inc. Numerous other individuals both inside and outside of EPA provided peer review of this document, and their suggestions contributed greatly to the quality and consistency of the final document. Data for some examples were used with permission of the following: Martin Wright of Diablo Canyon Nuclear Power Plant James Westmoreland of GEL Laboratories, Inc. Tammy Just, Southern Company Virginia Kammerdiener, Texas Department of Safety and Health Services Dedication This guide is dedicated to the memory of our friend and colleague, Dr. David McCurdy. Dave worked as a consultant for EMS for over 23 years, beginning with the Multi-Agency Radiological Laboratory Analytical Protocols (MARLAP) manual in 1994. Dave served as EMS’s QAPP Primary Investigator, instructed courses on topics such as MARLAP and basic radiochemistry, assisted in the method validation process, and was a key contributor to the publication of incident response guidance. In his spare time, Dave enjoyed fly-fishing, tennis, and traveling. He left many friends throughout EPA and the radioanalytical community, and he will be greatly missed. iii High Resolution Gamma Spectrometry Analyses For Normal Operations and Radiological Incident Response CONTENTS Preface .............................................................................................................................................. i Acknowledgements ........................................................................................................................ iii Contents ......................................................................................................................................... iv Acronyms and Abbreviations ...................................................................................................... viii Glossary .......................................................................................................................................... x Radiometric Unit Conversions ....................................................................................................... xi I. Background ............................................................................................................................... 1 A. Structure of the Document .................................................................................................2 B. Goals ...................................................................................................................................4 C. Objectives ...........................................................................................................................4 II. Processing Spectra for Identifying and Quantifying Gamma-ray Emitting Radionuclides ...... 4 III. Radioactive Decay Modes ........................................................................................................ 7 IV. Gamma Ray Identification ...................................................................................................... 11 A. Gamma Ray Interaction ....................................................................................................11 B. Potential Threat Radionuclides ........................................................................................13 C. Effects of High Activity Concentrations on Interferences and Identification ..................17 Low abundance gamma rays ............................................................................................17 Gamma-ray interferences not anticipated .........................................................................19
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