United States Nuclear Regulatory Commission - Protecting People and the Environment

Information Notice No. 82-18: Assessment of Intakes of Radioactive Material by Workers

                                                            SSINS NO.: 6835 
                                                            IN 82-18  

                               UNITED STATES 
                       NUCLEAR REGULATORY COMMISSION 
                    OFFICE OF INSPECTION AND ENFORCEMENT 
                           WASHINGTON, D.C. 20555 

                               June 11, 1982 

Information Notice No. 82-18:   ASSESSMENT OF INTAKES OF RADIOACTIVE 
                                   MATERIAL BY WORKERS 

Addressees: 

All nuclear power reactor facilities holding an operating license (OL) or 
construction permit (CP), research and test reactors, fuel facilities, and 
Priority 1 material licensees. 

Purpose: 

This information notice is provided to clarify the Nuclear Regulatory 
Commission (NRC) position on the use of ICRP-30 methodology for use in 
assessing intakes of radioactive materials by workers. No specific action or
response is required at this time. 

Description of Circumstances: 

Routine operations and unusual events at facilities handling radioactive 
material require, in some cases, the use of bioassay data to determine if an
exposure exceeded NRC regulatory limits. In 1979, the International 
Commission on Radiation Protection (ICRP) issued Publication 30, "Limits for
Intakes of Radionuclides by Workers"; this publication described dosimetric,
methods for evaluating the uptake of radionuclides and the associated dose 
commitment. New information on the uptake, deposition, and retention of 
radioactive material in the body, effect of radiation on the body, and decay
schemes of radionuclides, led the ICRP Committee II to publish this 1979 
revision to its earlier recommendations. These earlier recommendations were 
contained in ICRP-2, "Report of ICRP Committee II on Permissible Dose for 
Internal Radiation" (1959). Since the publication of ICRP-30, licensees have
been concerned about which models, equations, and assumptions the NRC 
considers acceptable in determining from bioassay data the quantity of 
radioactive material inhaled and the resulting dose commitment. This 
information notice is being issued to clarify the NRC position. 

Discussion: 

The present limits on exposure of individuals to concentrations of 
radioactive materials in the air in restricted areas (10 CFR 20.103) are 
based on concepts, models, equations, and assumptions adopted by the ICRP 
and published in ICRP-2. Since 1959, other ICRP publications have been 
issued supplementing ICRP-2 or applying the methods to particular exposure 
situations (ICRP-6, 9, 10, 10A, and 12). The NRC issued regulatory guidance 
on assessment of individual intakes of radioactive material in Regulatory 
Guide 8.9, "Acceptable Concepts, Models, Equations, and Assumptions for a 
Bioassay Program." In addition, other 

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                                                           June 11, 1982  
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regulatory guides have been issued providing guidance for the application of
bioassay for specific radionuclides or operations (Regulatory Guide 8.11 for
uranium, Regulatory Guide 8.26 for fission and activation products, 
Regulatory Guide 8.20 for iodine-125 and iodine-131, and Regulatory Guide 
8.22 for bioassay at uranium mills). The basic internal dosimetry concepts 
of the ICRP and the models, equations, and assumptions from these concepts 
in ICRP-2, 6, 9, 10, 10A, and 12 were used as the bases for each regulatory 
guide and are used by the NRC to evaluate bioassay data to determine 
compliance with regulatory requirements. The organ burdens, deposition 
fractions, retention functions, dose rates, and dose commitments obtained 
are based on ICRP-2 and data contained in ICRP-23, "Report of the Task Group 
on Reference Man." 

Since the ICRP issued the report of Committee II in 1959, ICRP-2 has been 
used as a guide for the control of intake of radioactive material in, the 
body to meet the basic standards of the ICRP. However, ICRP Committee II in 
ICRP-30 (1979) stated that new information on the effects of radiation on 
the body, on the deposition, uptake, and retention of radioactive matter in 
body tissue, and better data on radioactive decay schemes have accumulated 
in the 20-year intervening period since the publication of ICRP-2. Those 
factors and changes in the basic recommendations of the ICRP described in 
ICRP-26 (1977) made it necessary for the committee to publish a new report. 

Although the NRC has not yet incorporated by rule change the recommendations
of the ICRP contained in ICRP-26 or in ICRP-30, 10 CFR 20 is currently being
revised and if adopted, would embrace (in whole or in part) the new 
recommendations and methods of the ICRP. Until the regulations are changed, 
ICRP-2 remains the basis for the requirements in 10 CFR 20. Therefore, 
licensees must be able to demonstrate compliance using the ICRP-2 
methodology. 

NRC Position: 

The NRC will continue to use the ICRP-2 methodology in determining 
compliance with 10 CFR 20 until the revision of 10 CFR 20 has been published 
as a final rule. 

If you have any questions regarding this matter please contact the Regional 
Administrator of the appropriate NRC Regional Office, or this office. 

                                        
                                   Richard C. DeYoung, Director 
                                   Office of Inspection and Enforcement 

Technical Contact:  J. E. Wigginton 
                    301-492-4967 

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