[ RadSafe ] Regulatory guidance re: piece of the Chicago Pile

JPreisig at aol.com JPreisig at aol.com
Wed Oct 29 00:42:01 CDT 2014

    What a nice item to have.  The Roentgen rate  doesn't seem that high.  
At worst, keep it in a shielded container.   You've called the relevant 
regulator (state government) and they might even get  back to you.  The worst 
they could do is take it away from you???   There are probably already state 
regulators reading about this on Radsafe.   Some state workers I know from my 
home state are lurkers on Radsafe --- they  don't post much.
    It's not like it is cobalt from an irradiation source  that fell off 
the back of a truck, and kids are playing with it in the  street.  Just my 
opinion, mostly.
    Joe Preisig
In a message dated 10/29/2014 12:57:00 A.M. Eastern Daylight Time,  
carl.willis at gmail.com writes:

Hello  RADSAFErs,

I recently acquired a piece of the Chicago Pile (CP-1; the  first
nuclear reactor) from the wife of its original owner, Herbert  L.
Anderson.  And it potentially poses some regulatory challenges here  in
the USA that I feel I should address head-on in the interests  of
owning the item responsibly and bringing it to an appreciative  public
audience through museum loans and so forth.  I have already  shared my
questions with our own Carl Sullivan at the New Mexico  Radiation
Control Bureau via email, and await his response as  well.

The artifact under consideration is a "live block" from CP-1  composed
of AGOT graphite milled with two holes in which are installed  two
2.56-kg cylindrical fuel elements made of uranium metal. Photos  and
HPGe gamma spectra are available over private email; I don't  think
RADSAFE is able to handle attachments.  The graphite block  is
displayed in an acrylic case (the original was popping apart and  the
seams and I replaced it with modern solvent-welded acrylic).  It  is
mounted on a felt-bottomed wood base with a descriptive brass  plaque
announcing that the contents are "graphite and uranium used in  the
first self-sustaining nuclear chain reaction."  Contact exposure  rate
is about 7.5 mR / hr falling to about 3 mR / hr at four inches.   It
has been in the home of Herb and his wife from the time it was  given
to Herb (posited to be the 10th anniversary of the CP-1  criticality,
although I am now somewhat in doubt of that timeline...read  on) until
just this month, when it was given to me.

And here is the  regulatory question for anyone qualified to opine: In
my initial assessment  of the item's regulatory status I relied on
CP-1's known history of  essentially zero-power operation over less
than three months to ASSUME that  the two uranium fuel pieces
constituted an unimportant quantity of source  material.  However, in
my subsequent measurement of gamma spectra with  a germanium detector,
it is apparent that the dominant external radiation  from the fuel is
from byproduct material, i.e. Cs-137, and that the  approximate fuel
exposure amounts to some 100-200 kW-days per metric ton  of
U--inconsistent with CP-1 itself by orders of magnitude.  The  logical
explanation is that this fuel stringer was also used in CP-2  (the
rebuild of CP-1) before being turned into the commemorative  item.
And, with that information in hand, I'm not sure I can make  the
argument that the item falls under the unimportant source  material
general-license provisions.  I should emphasize that my goals  in
ownership of this unique historic artifact are to (A) take care of  it
properly of course; and (B) facilitate its loan to various  museums,
schools, or institutions where it may be appreciated by a curious  and
inquisitive public.  So should I try to pursue a specific license  for
it at the state level or via the NRC directly?  Should I still  treat
it as unimportant source material?  Does its creation predate  the
regulatory mandate of the NRC?  Should I just sit on it unless  and
until someone belly-aches about it, and deal with any issues as  they
may arise?

I am happy to discuss further; phone is 505-412-3277  or get in touch
with me via email.

Best regards
Carl  Willis
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