Date of Award
12-2025
Document Type
Thesis
Degree Name
Master of Science (MS)
Department
Environmental Health Physics
Committee Chair/Advisor
Nicole Martinez
Committee Member
Timothy DeVol
Committee Member
Caleigh Samuels
Abstract
Dose coefficients (DCs) and secondary limit values (such as the annual limit on intake [ALI] and derived air concentration [DAC]) are useful and convenient quantities in radiation protection (RP) for estimation of radiological dose and the practical application of dose limits. DCs link radioactivity intake to dose while secondary limit values express a dose limit in terms of the type and extent of exposure. The International Commission on Radiological Protection (ICRP), an international organization which provides guidance and recommendations for RP, calculates, tabulates, and updates DCs following new findings and updated knowledge relevant to dose determination (e.g. improved human biokinetics, updated nuclear decay data). The ICRP’s most recent general recommendations were published in 2007 with the following Occupational Intakes of Radionuclides (OIR) series (2015-2022) providing updated DCs for occupational intakes. The United States Nuclear Regulatory Commission (NRC), the primary body for licensing and regulation of radioactive materials use in the US, includes standards for RP in 10 CFR Part 20, with ALIs and DACs based on ICRP Publications 26 and 30 (1977 and 1979) tabulated in Appendix B for management of worker doses. Investigation of how and to what extent DCs and secondary limit values have changed following 43 years of updated knowledge may inform how NRC regulation may change following possible updates in the future. Quantification of change in DCs, ALIs, and DACs was completed by comparing ICRP Publication 30 and ICRP OIR series DCs and comparing 10 CFR Part 20 Appendix B secondary limit values with ALIs and DACs derived using ICRP OIR series DCs. Of 33 selected radionuclides, 38 committed equivalent DCs, 97 committed effective DCs, 38 non-stochastic ALIs (i.e. NALI), 97 stochastic ALIs (i.e. SALI), and 62 DACs were compared. Comparisons resulted in 98 of 135 ALI percentage changes and 45 of 61 DAC percentage changes being greater than 10% and 22 of 135 ALI and 10 of 61 DAC percentage changes being less than 10%. Comparisons varied widely in sign and magnitude across radionuclides, intake modes, and chemical forms.
Recommended Citation
Barker, Aidan B., "Comparison of the Recent ICRP Occupational Intakes of Rradionuclides Series to Annual Limits on Intake (ALI) in the United States for Select Radionuclides" (2025). All Theses. 4648.
https://open.clemson.edu/all_theses/4648