Adopting the International System of
Units for Radiation Measurements in
the United States
Proceedings of a Workshop
Ourania Kosti, Rapporteur
Nuclear and Radiation Studies Board
Division on Earth and Life Studies
THE NATIONAL ACADEMIES PRESS
THE NATIONAL ACADEMIES PRESS 500 Fifth Street, NW Washington, DC 20001
This activity was supported by Contract No. 200-2011-38807 TO# 50 with the Department of Health and Human Services’ Centers for Disease Control and Prevention. Any opinions, findings, conclusions, or recommendations expressed in this publication do not necessarily reflect the views of any organization or agency that provided support for the project.
International Standard Book Number-13:978-0-309-45388-2
International Standard Book Number-10:0-309-45388-7
Digital Object Identifier:10.17226/24645
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Copyright 2017 by the National Academy of Sciences. All rights reserved.
Printed in the United States of America
Suggested citation: National Academies of Sciences, Engineering, and Medicine. 2017. Adopting the International System of Units for Radiation Measurements in the United States: Proceedings of a Workshop. Washington, DC: The National Academies Press. doi: 10.17226/24645.
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WORKSHOP PLANNING COMMITTEE1
STEVEN L. SIMON, Chair, National Cancer Institute, Bethesda, Maryland
DANIEL J. BLUMENTHAL, U.S. Department of Energy, Washington, DC
E. VINCENT HOLAHAN, JR., U.S. Nuclear Regulatory Commission, Rockville, Maryland
MARK L. MAIELLO, New York City Department of Health and Mental Hygiene, Queens
RUTH E. McBURNEY, Conference of Radiation Control Program Directors, Inc., Frankfort, Kentucky
JESSICA WIEDER, U.S. Environmental Protection Agency, Washington, DC
OURANIA KOSTI, Study Director
TONI GREENLEAF, Administrative/Financial Associate
DARLENE GROS, Senior Program Assistant
1 The National Academies of Sciences, Engineering, and Medicine’s workshop planning committees are solely responsible for organizing the workshop, identifying topics, and choosing speakers. The responsibility for the published Proceedings of a Workshop rests with the workshop rapporteur and the institution.
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NUCLEAR AND RADIATION STUDIES BOARD
ROBERT C. DYNES, Chair, University of California, San Diego
JAMES A. BRINK, Vice Chair, Massachusetts General Hospital, Boston
GEORGE E. APOSTOLAKIS, Massachusetts Institute of Technology (emeritus), Cambridge
DAVID J. BRENNER, Columbia University, New York
MARGARET S. Y. CHU, M.S. Chu & Associates, LLC, Albuquerque, New Mexico
TISSA H. ILLANGASEKARE, Colorado School of Mines, Golden
CAROL M. JANTZEN, Savannah River National Laboratory, Aiken, South Carolina
MARTHA S. LINET, National Institutes of Health, Bethesda, Maryland
NANCY JO NICHOLAS, Los Alamos National Laboratory, Los Alamos, New Mexico
HENRY D. ROYAL, Washington University School of Medicine, St. Louis, Missouri
DANIEL O. STRAM, University of Southern California, Los Angeles
WILLIAM H. TOBEY, Belfer Center for Science and International Affairs, Cambridge, Massachusetts
SERGEY V. YUDINTSEV, Russian Academy of Sciences, Moscow
KEVIN D. CROWLEY, Director
JENNIFER HEIMBERG, Senior Program Officer
OURANIA KOSTI, Senior Program Officer
TONI GREENLEAF, Administrative and Financial Associate
LAURA D. LLANOS, Administrative and Financial Associate
DARLENE GROS, Senior Program Assistant
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This Proceedings of a Workshop was reviewed in draft form by individuals chosen for their diverse perspectives and technical expertise. The purpose of this independent review is to provide candid and critical comments that will assist the institution in making its published Proceedings of a Workshop as sound as possible and to ensure that the Proceedings of a Workshop meets institutional standards for objectivity, evidence, and responsiveness to the study charge. The review comments and draft manuscript remain confidential to protect the integrity of the process. We wish to thank the following individuals for their review of this Proceedings of a Workshop:
Frazier Bronson, Canberra Industries
Donald A. Cool, Electric Power Research Institute
Jerry W. Hiatt, Nuclear Energy Institute
Sigurður M. Magnússon, Icelandic Radiation Safety Authority
David R. Musick, Federal Emergency Management Agency
Richard J. Vetter, Mayo Clinic (retired)
Although the reviewers listed above have provided many constructive comments and suggestions, they did not see the final draft of the Proceedings of a Workshop before its release. The review of this Proceedings of a Workshop was overseen by Barbara L. Hamrick, University of California, Irvine, Medical Center. She was responsible for making certain that an independent examination of this Proceedings of a Workshop was carried
out in accordance with institutional procedures and that all review comments were carefully considered. Responsibility for the final content of this Proceedings of a Workshop rests entirely with the rapporteur and the institution.
Most countries in the world use the SI (Système International, also known as the metric system) units for radiation measurements in commercial and technical activities. The United States, in contrast, uses a mix of SI and conventional1 units for radiation measurements, despite 30-year-old national and international recommendations to exclusively use SI.
SI units for radiation measurements are the gray (unit for absorbed dose, Gy), becquerel (unit for activity, Bq), and sievert (unit for dose equivalent and effective dose, Sv). Conventional units are the rad, curie, and rem. The size of the SI and conventional units differs, and in some cases conversions are not arithmetically convenient: 1 rad = 0.01 Gy; 1 Ci = 3.7 × 1010 Bq; 1 rem = 0.01 Sv. Radiation professionals in the United States are faced with the need to understand both systems and make conversions between the two.
Several post–Fukushima Daiichi Nuclear Power Plant accident2 reports noted that the use of conventional units in the United States and the need to convert to/from SI hindered the exchange and interpretation of information during the accident response. The experience from the Fukushima nuclear accident led the Centers for Disease Control and Prevention to ask the Nuclear and Radiation Studies Board of the National Academies of Sciences, Engineering, and Medicine (the National Academies) to host this workshop, Adopting the International System of Units for Radiation
1 Also referred to as “traditional.”
2 The Fukushima Nuclear Plant accident was initiated by the March 11, 2011, Great East Japan Earthquake and Tsunami.
Measurements in the United States. Its objective was to obtain perspectives from the radiation protection and user communities on potential communication improvements associated with adopting SI units for radiation measurements in the United States.
The workshop was held September 29-30, 2016, at the National Academies in Washington, DC. It was organized by a committee of six experts3 and featured a range of presentations4 on the topics listed in the statement of task (see Box P.1). The workshop was undertaken with the premise that adoption of the SI units for radiation measurements would improve the effectiveness of responding to national and international radiation emergencies and communicating with the public and among radiation experts.
This Proceedings of a Workshop, prepared by Dr. Ourania Kosti, who is a National Academies staff member, serves as a record of the workshop. It does not provide findings or recommendations or represent a consensus of workshop participants. Dr. Kosti is responsible for the overall quality and accuracy of this proceedings.
This proceedings is organized into five chapters:
- Chapter 1 introduces the issue of adoption of SI units for radiation measurements in the United States.
- Chapter 2 summarizes current (as of September 2016) practices in use of units for radiation measurements in the United States.
- Chapter 3 summarizes the issues with continuing use of conventional units for radiation measurements and benefits and challenges of exclusive use of SI.
- Chapter 4 discusses lessons learned from international experience in adopting the SI units for radiation measurements.
- Chapter 5 describes options on possible next steps forward toward the exclusive use of SI units for radiation measurements in the United States.
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|AAPM||American Association of Physicists in Medicine|
|ACR||American College of Radiology|
|ASTHO||Association of State and Territorial Health Official|
|ASTRO||American Society for Radiation Oncology|
|CDC||Centers for Disease Control and Prevention|
|CGPM||General Conference on Weights and Measures (French: Conférence générale des poids et mesures)|
|CFR||Code of Federal Regulations|
|CNSC||Canadian Nuclear Safety Commission|
|CRCPD||Conference of Radiation Control Program Directors, Inc.|
|CTOS||Counterterrorism Operations Support|
|DHS||Department of Homeland Security|
|DOD||Department of Defense|
|DOE||Department of Energy|
|DOT||Department of Transportation|
|EPA||Environmental Protection Agency|
|EURATOM||European Atomic Energy Community|
|EURDEP||European Radiological Data Exchange Platform|
|FEMA||Federal Emergency Management Agency|
|HERCA||Heads of the European Radiological Protection Competent Authorities|
|IAEA||International Atomic Energy Agency|
|ICRP||International Commission on Radiological Protection|
|ICRU||International Commission on Radiation Units and Measurements|
|INPO||Institute for Nuclear Power Operations|
|NATO||North Atlantic Treaty Organization|
|NCI||National Cancer Institute|
|NCRP||National Council on Radiation Protection and Measurements|
|NEI||Nuclear Energy Institute|
|NIST||National Institute of Standards and Technology|
|NRC||Nuclear Regulatory Commission|
|OMB||Office of Management and Budget|
|OSHA||Occupational Safety and Health Administration|
|OSTP||Office of Science and Technology Policy|
|PAG||Protective Action Guide|
|REAC/TS||Radiation Emergency Assistance Center/Training Site|
|REP||Radiological Emergency Preparedness|
|SNMMI||Society of Nuclear Medicine and Molecular Imaging|
|T-TIP||Transatlantic Trade and Investment Partnership|
|UNSCEAR||United Nations Scientific Committee on the Effects of Atomic Radiation|
|U.S.||United States of America|