[ RadSafe ] More questions about 10CFR 20
matzkin at invap.com.ar
Tue Jun 3 11:31:54 CDT 2008
I'm now fighting with Section 20.1302 (Compliance
with dose limits for individual members of the
public) of 10CFR 20. I have some questions
concerning the possible ways of demonstrating
compliance with the dose limits for individual
members of the public. Quoting again:
(b) A licensee shall show compliance with the
annual dose limit in § 20.1301 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 part 20; and
(ii) If an individual were continuously 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 (2) seems pretty strightforward. However,
I wonder about option (1) since it looks more
like the approach set by the Argentinean
regulatory body. When applying for a license, the
applicant has to assess the allowable activity
for each individual radionuclide (Ki) to be
released (as if radionuclide "i" was the only one
to be released) and demonstrate that the
summation -over all radionuclides released- of
the ratios Si/Ki, where Si is each of the
individual activities to be released, is lower
than or equal to 1. That is, SUM(Si/Ki) < 1.
This formula ensures that the total effective
dose equivalent to the critical group will be
within prescribed limits. The Ki's are calculated
through a long process which requires many data:
meteorological, hydrological, agricultural,
population distribution, even food consumption
habits of the people living in the region, as
well as dosimetric factors associated to each radionuclide.
And now the questions:
a) which is the customary approach to demonstrate
compliance with dose limits to the public when
applying for the licensing of a nuclear (not power) facility in the USA?
b) when (or if) option (1) is used, is the
procedure similar to what I've described above?
if so, which is the official -if there is one-
source for the dosimetric factors? I've searched
through the NRC site but didn't find anything related.
Sorry for the long post. Once again, I'll appreciate your inputs.
Nuclear Engineering Department
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