[ RadSafe ] RE: regs- take the quiz

Grove, Thomas W. thomas.grove at nist.gov
Thu Sep 10 14:47:15 CDT 2009

IMO, the author's answer to Question #1's is not correct.

10CFR35.75 does not state the 500 mrem release limit as an annual  limit (it seems to imply a per occurrence limit). Therefore, it cannot be considered into the annual dose limit for members of the public.

More importantly, 10CFR20.1301 specifically excludes the contribution of this dose to members of the public, "exclusive of the dose contributions from background radiation, from any administration the individual has received, from exposure to individuals administered radioactive material and released under § 35.75."

Question #1 is also incomplete. There are several qualifiers, some of which are:  Is this a limit based upon an licensed operation? If so, the annual limit is 100 mrem. Does the licensee have pre-approval from the NRC to exceed 100 mrem/year? If so, the limit could be as high as 500 mrem/yr. Is the facility decommissioned? If so, the limit is 25 mrem/yr. (not heavy on D&D limits, but this sticks in my mind for some reason)

In addition, the annual limits of 10CFR20.1301 applies to each licensee, so it is theoretically possible for a member of the public to receive >annual limit, when total exposure from multiple licensees is accounted for.

Adding to the issue is 10CFR20.1101 which limits air emissions to 10 mrem/yr to members of the public.

I don't even know where to begin rebutting Question #3 and its answer.

Some smart guy once said, "Believe none of what you read and half of what you see." So verify (and correct if necessary) my words as well!  ;)

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