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MDA of radionuclides (Regulatory Issues)
Just to clarify.......
you can filter, purify, or use some other means of removing the radioactive
contaminants and then recount to the RETS LLD. If it comes out
clean.....you were successful, go ahead and free release.
----------
From: LIPTONW
To: Multiple recipients of list
Subject: Re: MDA of radionuclides in soil (Regulatory Issues)???
Date: Monday, February 26, 1996 6:52
--Boundary-1621187-0-0
In response to Jim Barnes's concern that the MDA's I quoted are release
limits:
They are NOT release limits. Nothing with detectable licensed material can
be
free released. These are, however, standards which specify how hard we have
to look for "detectable" activity. Once licensed material is found,
however,
the material is considered radioactive. It CANNOT be diluted, etc. to get
below the MDA.
Bill Lipton
--Boundary-1621187-0-0
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Received: 23 Feb 1996 19:30:09 Sent: 23 Feb 1996 18:28:57
From:"root@romulus.ehs.uiuc.edu" <root@romulus.ehs.uiuc.edu>
To: Multiple,recipients,of,list,radsafe@romulus.ehs.uiuc.edu
Subject: Re: MDA of radionuclides in soil (Regulatory Issues)???
Reply-to: radsafe@romulus.ehs.uiuc.edu
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Anastasios Kotsikonas
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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
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>
>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
>X-Orcl-Application: Sender: radsafe@romulus.ehs.uiuc.edu
>X-Orcl-Application: Precedence: bulk
>X-Orcl-Application: X-Listserver-Version: 6.0 -- UNIX ListServer by
Anastasios
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--
>
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