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).