United States Nuclear Regulatory Commission - Protecting People and the Environment

Health Physics Questions and Answers - Question 68

Question 68: This question concerns demonstration of compliance with the dose limits for individual members of the public. Section 20.1302 (b), in the revised 10 CFR Part 20, permits the licensee to demonstrate compliance by:

1 "Demonstrating by measurement or calculation that the total effective dose equivalent to the individual likely to receive the highest dose from the licensed operation does not exceed the annual dose limit; or

2 Demonstrating that: (i) the annual average concentrations of radioactive material released in gaseous and liquid effluents at the boundary of the unrestricted area do not exceed the values specified in Table 2 of Appendix B to §§20.1001 - 20.2401; and

(ii) if an individual were continually present in an unrestricted area, the dose from external sources would not exceed 0.002 rem (0.02 mSv) in an hour and 0.05 rem (0.5 mSv) in a year."

Option (1) above would require the utility to demonstrate compliance with the 100 mrem in a year specified in Section 20.1301 and the limits to a member of the public specified in 40 CFR 190. This option allows for the use of occupancy factors. However, the 10 CFR Part 2 Appendix C - General Statement of Policy and Procedure for NRC Enforcement Actions Conforming Amendments, provides an example of a Severity IV violation based on option '2' above which does not account for occupancy factors.

It can be interpreted that the enforcement examples have been written more conservatively than the rule revision. This unnecessary restriction could severely limit availability of power, particularly at BWRs operating with hydrogen water chemistry, without a corresponding reduction in actual dose to the public. It is requested that these examples of violations be clarified to ensure consistency with the regulation.

Answer: The enforcement examples in question are consistent with the corresponding regulations. "Option 2" [10 CFR 20.1301 (b) (2)] does not allow for use of occupancy factors other than unity. 10 CFR 20.1302 (b) (2) (i) concerns effluent concentrations, which do not involve occupancy, and 10 CFR 20.1302 (b) (2) (ii) involves the assumption that an individual is continually present in the area or, in other, words, 10 CFR 20.1302 (b) (2) (ii) requires the assumption of an occupancy factor of 1.0.

(Reference: 10 CFR 20.1302)

Page Last Reviewed/Updated Thursday, September 24, 2015