RE: Accidents and Dose Limits

["Jim F. Herrold" <Herrold@UWyo.Edu>]

Will:

Your question stirred something in the back of my brain about NRC
exposure limits as they pertain to accidents. It took me a while to find
the context in which I had read it. Once I found it, I wasn't sure if it
would help, but I am offering the reference anyway.

In NRC Regulatory Guide 8.34 on Monitoring Criteria and Methods to
Calculate Occupational Radiation Doses, section C.1.1, it talks about
the monitoring criteria in 10 CFR 20.1502(a) (which basically says you
must monitor if workers are LIKELY to receive 10 percent of their
respective limits). In evaluating this necessity for personnel
monitoring, it says, "The potential for unlikely exposures and accident
conditions need not be considered because these events, by definition,
are not likely." Regulatory Guide 8.7 on Recording and Reporting
Occupational Radiation Exposure Data says, "If it is determined that
monitoring is not required and a subsequent evaluation shows that the 10
percent has or will be exceeded, the dose received ...should be
estimated, recorded, and reported."

This, of course, talks about occupational limits. All I can find about
exposures to the public is, in 10 CFR 20.2203 it says a licensee must
report to the NRC any incident in which the limits to an individual
member of the public have been exceeded. You would have to ask the NRC
or your State where they would take it from there.


Jim F. Herrold
Radiation Safety Officer
University of Wyoming
Environmental Health & Safety
312 Merica Hall
Laramie, WY 82071

herrold@uwyo.edu
(307) 766-3277

DISCLAIMER: Nothing I say, write, or think (including this disclaimer)
represents the positions held by the University of Wyoming, Trustees,
President or ANYONE.



>----------
>From: 	William McCabe[SMTP:WMCCABE@tnrcc.state.tx.us]
>Sent: 	Friday, November 21, 1997 5:28 PM
>To: 	Multiple recipients of list
>Subject: 	Accidents and Dose Limits
>
>I am having a discussion with our legel staff regarding accidents and
>dose limits.  Our legal people are telling me that the regulatory dose
>limits (100 mrem/yr as well as the 25 mrem whole body, 75 mrem thyroid,
>and 25 mrem other organ to any member of the public) and effluent
>concentration limits (i.e. 10CFR20, App B) and other such limits, as
>applicable, apply.  Their opinion is based on how they are reading our
>state equivalent of 10CFR (essentially the same as 10 CFR).   (It seems to
>me that this is like saying it is agtainst the law to receive anything more
>than minor cuts and bruises ANY traffic accident.)
>
>It has always been my understanding that you cannot apply a regulatory
>dose limit or effluent concentration limit to a radiological  accident.  All
>you
>can do is plan and prepare for any reasonable or credible accident
>situation and do everything you can to prevent the accident from
>occurring and take action to mitigate the consequences of the accident if
>it should occur.  (To continue my earlier analogy... install automobile
>safety devices, design vehicle to absorb and distribute impact energy
>away from passenger, require seat belt use, etc.  This will not prevent
>exceeding minor cut and bruide injuries, but will (should) help minimize
>more serious injuries and death).
>
>I'd appreciate any comments and especially references and other state
>and federal regulatory positions or guidance on this subject from the
>RADSAFE community to help clear up either my or my legal people's (or
>both our) misconceptions.
>
>Thanks in advance.
>
>Will McCabe
>wmccabe@tnrcc.state.tx.us
>