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Re: NRC provides generic soil criteria (DCGLs) using latestversion o
Interested RADSAFERs:
Since a number of you posted to RADSAFE regarding the Nuclear Regulatory Commission's Federal Register Notice (FRN) on generic soil criteria for decommissioning (December 7, 1999, Volume 64, number 234, pages 68395-68396), I wanted to mention a few clarifications :
(1) I first note that Eric Abelquist's post seems to have dropped the actual FRN (which it appears he intended to include (looks like it fell victim to the "from" at the beginning of a paragraph problem)). I won't post the FRN here, but if people are interested, it can be found at URL:
http://frwebgate.access.gpo.gov/cgi-bin/getdoc.cgi?dbname=1999_register&docid=99-31508-filed
If anyone is interested and does not have browser access, I could e-mail a copy of the FRN (please ask me directly, not to RADSAFE).
(2) Eric's note described the concentration values as DCGLs (derived concentration guidelines). As Mike Madonia pointed out (thanks, Mike), and as described in the FRN, "The table is intended for use as screening criteria to facilitate license termination for many simple routine decommissioning cases that do not require a site-specific dose assessment. For facilities with contamination levels above those in Table 3 [of the FRN], additional site-specific dose assessments may be necessary,..."
Thus, the table of values are screening values, and individual facilities are able to generate more site-specific values for their site, using site-specific dose assessments.
The screening values are intended to apply to almost all facilities, without site-specific knowledge, and thus may be overly restrictive when site-specific knowledge is available.
(3) As Keith Anderson noted, the basis for EPA's 5 pCi/g limit in 40 CFR 192 was not strictly a dose-based limit. There was a risk basis to that limit, but the limit was developed more than 15 years ago, and the basis is not the same as the NRC's license termination rule (see EPA's EIS for details).
(4) A few people (Elizabeth Algutifan, Bill Goldsmith, and Keith Anderson) were essentially asking whether the screening concentrations are in excess of background. In my reading of the FRN, this question was not clearly answered. But, the regulation (10 CFR 20, Subpart E) indicates (20.1402) that the unrestricted release dose limit applies to "residual radioactivity that is distinguishable from background..." The definition of residual radioactivity states that background radiation is excluded. So, the screening concentrations (or any site-specific DCGLs) are intended to apply to the amount of radioactivity concentration that is above or greater than background.
(5) The FRN indicates that NRC is accepting comments on the table of screening values. I would certainly encourage people to formally comment, if they are interested. The comment period is 30 days from the FRN release. Please refer to the FRN for details on how to provide comments.
(6) DISCLAIMER: I intend this response only to clarify some information being discussed. I do not intend this to be a formal NRC response to comments on the FRN--that is handled under a formal process that starts with acceptance of comments--it is only a response to RADSAFE discussion. As usual, this is only my opinion, and does not represent NRC policy.
Duane.
Duane Schmidt, CHP
U.S. Nuclear Regulatory Commission
Office of Nuclear Material Safety and Safeguards
Division of Waste Management
Decommissioning Branch
Mail Stop T-7F27
Washington, DC 20555
mailto: dws2@nrc.gov
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