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RE: NRC provides generic soil criteria (DCGLs) using latest
The FRN 07de99-106 values may appear, at first blush, to be rather low. I'd
raise two points regarding these values:
1) For the last 2-3 years it has been commonplace for NRC licensees
(undergoing decommissioning plan submittal/execution) to consider the
development of dose-based remediation criteria. Many licensed sites
currently undergoing D&D have radionuclide Derived Concentration Guidelines
(DCGLs) that approach the very restrictive screening values shown in the
FRN. Use of "near-background" DCGLs for naturally-occurring radionuclides
has required licensees to apply the statistical methods of the MARSSIM and
supporting guidance to define characterization and termination sampling
requirements. Likewise, many facilities undergoing the CERCLA process have
derived risk-based "guideline values" to guide removal actions and decisions
for no further action. Many of these guideline values are extremely
restrictive (near background) when derived using target risks of 1 E-6 or 1
E-5.
2) Perhaps more importantly, one should note that the FRN 07de99-106 values
are to "use as screening criteria to facilitate license termination for many
simple routine decommissioning cases that do not require a site-specific
dose assessment." The important distinction is that if you have soil
concentrations exceeding these values, you probably are going to have to
perform a bit more sophisticated pathway/dose analyses using the referenced
tools. One must note the very conservative nature of the input parameters
used in the hypothetical DandD modeling runs. Slight changes to default
parameters can dramatically change the resultant radionuclide DCGLs for both
soil and building surfaces. It has been my experience (in supporting
multiple clients undergoing the license termination process), that the
discourse on the use of site-specific modeling parameters (and the resultant
DCGLs that are higher)is a healthy process. The licensee is urged to
understand the physical nature of their site and existing characterization
data, while the regulator exercises reasonable judgement in the acceptance
of DCGLs that are higher than the screening values. The typical end product
is a set of remediation criteria (DCGLs) that are higher than the screening
values, yet protective of public health.
Michael Madonia
Sr. Client Service Mgr.
Decommissioning Programs
Roy F. Weston, Inc.
3 Hawthorn Pkwy., Suite 400
Vernon Hills, IL 60061-1450
-----Original Message-----
From: steve.rima@DOEGJPO.COM [mailto:steve.rima@DOEGJPO.COM]
Sent: Tuesday, December 07, 1999 3:07 PM
To: Multiple recipients of list
Subject: Re: NRC provides generic soil criteria (DCGLs) using latest
Very interesting reading. Does anyone else find at least some of these
values to be incredibly low? For example, the EPA has codified (40 CFR
192, Subpart B) the soil cleanup level for Ra-226 from uranium
processing activities to be 5 pCi/g above background for the top 15 cm
of soil, and 15 pCi/g for deeper soil. Using the NRC's calculated
concentration of 0.7 pCi/g that would result in 25 mrem/y, the EPA's
standardized cleanup level of 5 pCi/g would equal 179 mrem/y!!! Seems
to be more than just a little disagreement here.
Wouldn't it be nice if the various regulatory agencies that are
attempting to regulate D&D activities could agree? I guess I'll wish
I'd win the lottery while I'm at it. Hmmm, I wonder which one will
happen first.
My opinion only
Steven D. Rima, CHP, CSP
Manager, Health Physics and Industrial Hygiene
MACTEC-ERS, LLC
steven.rima@doegjpo.com
______________________________ Reply Separator
_________________________________
Subject: NRC provides generic soil criteria (DCGLs) using latest vers
Author: "Abelquist; Eric" <AbelquiE@orau.gov> at Internet
Date: 12/7/99 1:21 PM
Dear Radsafers-
Please note the attached Federal Register notice from the NRC related to
soil concentrations that correspond to the 25 mrem/y release criterion. The
NRC has used an updated version of DandD (somewhat less conservative default
parameter values). Some of the more common radionulcide DCGLs (in pCi/g)
are as follows:
Co-60..................................... 3.8 E+00
Sr-90..................................... 1.7 E+00
Cs-137.................................... 1.1 E+01
Ra-226.................................... 7.0 E-01
Ra-226+C \4\.............................. 6.0 E-01
Th-232.................................... 1.1 E+00
Th-232+C.................................. 1.1 E+00
U-234..................................... 1.3 E+01
U-235..................................... 8.0 E+00
U-235+C................................... 2.9 E-01
U-238..................................... 1.4 E+01
U-238+C................................... 5.0 E-01
Check it out.
Regards,
Eric Abelquist
Eric W. Abelquist
ORISE
P.O. Box 117
Oak Ridge,TN 37831
Tel (423) 576-3740
FAX (423) 241-3497
Email: abelquie@orau.gov
[Federal Register: December 7, 1999 (Volume 64, Number 234)]
[Notices]
[Page 68395-68396]
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