United States Nuclear Regulatory Commission - Protecting People and the Environment

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)

Page Last Reviewed/Updated Thursday, March 29, 2012