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Re[2]: MDA of radionuclides in soil (Regulatory Issues)???
For DOE sites in the state of ****, MDA's do not appear to be steeped in logic
or to have technical merit. It seems to be based on "tribal knowledge", which
prevails to this day.
For example, at the ****** facility, the MDA for total uranium for the facility
monitoring program, is 0.1 pCi/gr (or liter). The Bureau of Radiation
Protection for the state has asked many times as to "why" this level is so far
below background. It turns out that "this is the way it is". Each DOE facility
operates (to my observation) in an autonomous fashion, using whatever MDA's they
deem to be appropriate so as to detect levels of activity above background.
After a year of "banging my head against a concrete wall", I have decided to
accept these tremendouly low levels and continue to do my job until some one
greater and better decides to standardize or rationalize instument MDA's for
environmental monitoring programs.
P.S. I agree with Jim Barnes as to cringing at a 5 billion second count to
detect a fractional pCi/gr (l) of anything.
______________________________ Reply Separator _________________________________
Subject: Re: MDA of radionuclides in soil (Regulatory Issues)???
Author: radsafe@romulus.ehs.uiuc.edu at Internet
Date: 2/23/96 6:30 PM
Good morning;
I read Bill's note with some interest. But I must admit that I am a bit
confused
by this. In my former life in commercial nuclear, I was explicitly told by an
NRC inspector that the Tech Spec LLDs were NOT to be interpreted as a "maximum
acceptable" anything, as that was tantamount to a deminimis release limit, and
the NRC did not recognize such deminimis limits (this all, of course, revolving
around the dark planet of "detectable peak" as the basis for declaring something
as radioactive). [This is circa 1984; Region 1].
Later (1993; Region IV) I was given a listing of the NRC soil limits for
facility
release ("Policy and Guidance Directive FC83-23: "Termination of Byproduct,
Source and Special Nuclear Material Licenses"). This document specifies no
acceptable concentrations, saying that they will be determined on a case by case
basis. Then in another attached chart (I think from an EPA document), levels of
5 - 15 pCi/g are listed for the main byproduct players. If these are the
limits,
then one would think these would also be the LLD (but I've even been told that
THAT is not even true. Several inspectors have said that we had to detect to
levels below the limit).
I have always had the consideration that the regulators were using LLD to set
release limits. Thus, I have always cringed when the count room folks tell me
that they got some fractional pCi/g for Cs-137 after a 5 billion second count,
as
that is a detectable peak, and that makes the material radioactive. Has the
regulatory community revisited this rule and broken the vicious circle? If so,
would someone please point me to the relevant guidance?
Thanks,
Jim Barnes, CHP
RSO
Rocketdyne Divison; Rockwell Aerospace
--------------------------------------------------------
You wrote:
>
>
>--Boundary-1613719-0-0
>
>The licensing documentation (Technical Specifications, Offsite Dose
>Calculation Manual, etc.)for nuclear power plants specify detection
>capabilities for environmental sample analysis. These are defined as the
>maximum acceptable LLD's. Although none are specified for soil, the LLD's for
>"sediment", in units of pCi/kr (dry) are 150 for Cs-134 and 180 for Cs-137.
>These are 10X the LLD's for water, in units of pCi/liter. We thus generally
>take the required LLD's for sediment as 10X those for water. They would be:
>H-3 20000
>
>Mn-54, Co-58, Co-60, Zr-95, Nb-95, Ba-140, and La-140 150
>
>Fe-59 and Zn-65 300
>
>I-131 10
>
>Contact me directly if you need additional information.
>
>Bill Lipton
>
>
>
>--Boundary-1613719-0-0
>X-Orcl-Content-Type: message/rfc822
>
>Received: 23 Feb 1996 10:16:27 Sent: 23 Feb 1996 09:15:03
>From:"root@romulus.ehs.uiuc.edu" <root@romulus.ehs.uiuc.edu>
>To: Multiple,recipients,of,list,radsafe@romulus.ehs.uiuc.edu
>Subject: MDA of radionuclides in soil
>Reply-to: radsafe@romulus.ehs.uiuc.edu
>X-Orcl-Application: Errors-To: melissa@romulus.ehs.uiuc.edu
>X-Orcl-Application: Originator: radsafe@romulus.ehs.uiuc.edu
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Kotsikonas
>X-Orcl-Application: X-Comment: Radiation Safety Distribution List
>
>
>Does anybody know of a reference which has values of realistically
>achievable Minimum Detectable Activities for various radionuclides (as many
>as relevant) in soil?
>
>Thanks,
>
>Kim Kearfott.
>
>
>**********************************************************************
> Kim Kearfott, Sc.D., C.H.P.
>
>Professor Director of Faculty Development
>Program Advisor, & Faculty/Women in Engineering Office
> Radiological Health Engineering College of Engineering
>Dept. of Nuclear Engineering
> & Radiological Sciences
>University of Michigan University of Michigan
>Ann Arbor, MI 48109-2104 Ann Arbor, MI 48109-2116
>
> telephone: (313) 763-9117
> fax: (313) 763-4540
> e-mail: kearfott@umich.edu
>**********************************************************************
> TIME, DISTANCE, AND SHIELDING: Good for what ails you!
>**********************************************************************
>
>
>
>
>--Boundary-1613719-0-0--
>