RE: Decay Storage Requirements

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

I've often wondered this myself. We've had it in our license and have
been dutifully following it for years. My suspicion is that the
10-half-life figure was chosen because, after this period of time, the
original activity has been reduced by slightly more than 1/1000. (A
round figure that sounds good to regulators but, as stated by others, it
all depends on how much you start out with.)

Has anyone out there ever successfully gotten the NRC to approve
disposal of  waste once the levels of contamination are effectively
background WITHOUT having to go through the decay-in-storage for
10-half-lives? For waste minimization and conservation of storage space,
don't we tell users to frisk first before putting a whole benchtop
blotter in the rad waste? Isn't that the same thing?

In their advanced notice of proposed rulemaking on Broad Scope Materials
Licenses (FR 58346) the NRC asks for comments on the question, "What
balance should be maintained between a performance-based and a
prescriptive approach to regulating Broad Scope Licenses?" They sound
like they really want to revise regulations to be more risk-informed.
Everyone affected should take the time to let them know what we think on
this issue.

STANDARD DISCLAIMER: "I didn't do it."


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

herrold@uwyo.edu
(307) 766-3277

>----------
>From: 	William Lorenzen[SMTP:LORENZEN_W@A1.TCH.HARVARD.EDU]
>Sent: 	Thursday, December 05, 1996 5:58 AM
>To: 	Multiple recipients of list
>Subject: 	Decay Storage Requirements
>
>What is the scientific/technical basis for the regulatory requirement of
>holding radioactive wastes for a minimum of 10 half-lives prior to release.