United States Nuclear Regulatory Commission - Protecting People and the Environment

U.S. Nuclear Regulatory Commission

Question 122: The conforming amendment to 10 CFR 50.73 (a)

(2) states that reports submitted in accordance with 10 CFR

50.73 (a) (2) (viii) also meet the effluent release

reporting requirements of 10 CFR 20.2203 (a) (3). However,

10 CFR 20.2203 (a) (3) requires reporting of concentrations

in an unrestricted area of 10 times any applicable limit in

Part 20 while 10 CFR 50.73 (a) (2) (viii) requires reports

of airborne or liquid effluent releases that exceed 20

times the applicable concentration limits in Table 2,

Appendix B. Why is the multiple ten in one case and twenty

in the other?

Answer: The two reporting requirements are consistent in

terms of public dose. The annual dose limit for a member

of the public is 100 mrem. 10 CFR 20.2203 (a) (3) requires

reporting above a threshold of ten times this applicable

limit, or 1000 mrem. The concentrations in Table 2,

Appendix B, correspond to an annual dose of 50 mrem;

therefore, the requirement in 10 CFR 50.73 (a) (2) (viii)

for reporting at 20 times these concentrations corresponds

to a reporting threshold in terms of annual dose, of 20 x

50 mrem, or 1000 mrem, which is the same dose threshold as

that in 10 CFR 20.2203 (a) (3). (References: 10 CFR

20.2203, 50.73)

Page Last Reviewed/Updated Thursday, March 29, 2012