RE: Decommissioning problem

["Boone, Darren" <Darren.Boone@rfets.gov>]

Greg,

We experience similar problems with plastic items and any plastic
impregnated glass.  If you determine that the contamination is not due to
radon progeny, I would recommend the Surface Contaminated Object (SCO)
method of waste disposal.  Information can be found in NUREG 1608 and
49CFR173.433.  I also think the containers are cadmium lined.

Darren Boone
Rad Safety Manager
B771, RFETS

	-----Original Message-----
	From:	Greg Krause [SMTP:greg_krause@operations.und.nodak.edu]
	Sent:	Tuesday, August 15, 2000 12:58 PM
	To:	Multiple recipients of list
	Subject:	Decommissioning problem

	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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