Re: Decommissioning problem

[Rachid Zitouni <azittouni@yahoo.com>]

Greg,

This type of operation needs to be done by following
appropriate radiation protection rules. You can't just
do a guessing work and feel satisfied to get rid of
the contaminated material. Your approach is contrary
to good practice and ill advised.
You should collect all available information on the
dismantled installation and perform all necessary
measurements before disposing of the left components.
The decommissioning of this type of installation needs
to be performed in accordance with the applicable
regulations.
If you experience problems, you should get on-site
help from a qualified health physicist so as to avoid
any injury.
I am surprised you're not in possession of all the
required records regarding the site to be cleaned.
By the way, has anyone performed leak tests on the
fuel elements before taking them away?
Since you did not provide enough useful information,
one is tempted to ask a number of questions regarding
the safety precautions taken during the dismantling
operation.

Regards,

Abderrachid Zitouni

 
<greg_krause@operations.und.nodak.edu> wrote:
> I inherited the clean up of an old subcritical
> reactor.  The fuel and PuBe sources are gone (thank
> you Sherry Jones and the Y-12 people), but:
> 
> the fuel and other U itmes were stored with Aluminum
> reactor components in a small sealed room for many
> years.  All of the Aluminum items now appear to be
> contaminated when I perform  wipe tests on them
> using liquid scintillation.   Other items in the
> room: cardboard, wood, steel don't appear to be
> contaminated.  Is this consistent with deposition of
> radon daughter products? (leaded glass is also
> contaminated while the metal frame is not.) 
> Contamination levels appear to be around 300 - 1000
> dpm/100 cm2.
> 
> The contamination appears to wipe off easily with
> detergent, so I have a choice of contaminated
> aluminum or contaminated paper towels.  Assuming
> that the contamination is radon daughters, how to
> dispose of the bags of towels?  
> 
> Final question:  although I got rid of the PuBe
> sources, I still have the storage container.  Its a
> large aluminum can filled with parafin, but would
> anyone know what the thin sheet of soft, gray metal
> is that's apparently used as the thermal neutron
> absorber?  I need to know, because unless someone
> out there wants it, I intend to send it to the
> landfill.  The only info I have on the container is
> that a tag on the outside reads: Universal Nuclear,
> New York, NY
> 
> Greg Krause, P.E.
> Director, Radiation  & Chemical Safety
> University of North Dakota
> 701-777-3341
> greg_krause@operations.und.nodak.edu
> 
>
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=====
Dr. Abderrachid Zitouni, PhD
Cite Ain Allah - Bat. 205 A
Apt. 05 - Dely Brahim -
Algiers - ALGERIA
Phone: +213 2 36 65 51
Fax:   +213 2 74 96 38
e-mail: azittouni@yahoo.com

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