United States Nuclear Regulatory Commission - Protecting People and the Environment

U.S. Nuclear Regulatory Commission

Question 461: Does the word "applicable" in the phrase

"applicable ALI (s)" in 10 CFR 20.1502 (b) (1) mean that

the stochastic ALI (s) [SALI (s)] should be used?

It is noted that 10 CFR 20.1502 (b) requires the licensee

to monitor the occupational intake and assess the committed

effective dose equivalent. We believe that the answer to

this question should be yes, if a licensee is operating

under the "more limiting" dose limit of 5 rem TEDE. The

occupational dose limits in 10 CFR 20.1201 apply to the

"more limiting" of 5 rem TEDE or 50 rem TODE. If a

licensee's prospective assessment shows that the exposure

conditions at their facility is most likely to be limited

by the 5 rem TEDE limit, then the "applicable" ALI is the

SALI. This is further shown by the wording used in 10 CFR

20.1502 (b); i.e., use of the "committed effective dose

equivalent" terminology.

Answer: No, not necessarily. The "applicable" ALI is the

ALI for the appropriate radionuclide, the appropriate

column (inhalation or ingestion), and, for inhalation ALIs,

the appropriate "class" (D, W, or Y). When both a

stochastic and a non-stochastic inhalation ALI are listed

for a particular radionuclide (e.g., for I-131), the

"applicable ALI" in 10 CFR 20.1502 (b) means the more

limiting ALI, which is listed first (the non-stochastic

ALI), not the stochastic ALI, which is listed second and is

shown in parentheses. The statements made by the questioner

following the question are not relevant to the question.

(Reference: 10 CFR 20.1502).

Page Last Reviewed/Updated Thursday, March 29, 2012