U.S. Nuclear Regulatory Commission
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;
(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)