[ RadSafe ] Plastics and radiation exposure

[Brennan, Mike (DOH)]

Years ago I was at an ALARA conference at Hanford, and one of the
presentations was about the challenges of getting some work done in a
large "hot cell" (almost the size of a handball court).  The problem was
that the radiation field at one end was about 50,000 R/h, and getting
the pneumatic tools in place (working from behind shielding at the other
end of the room) would sometimes take so long that the plastic/rubber in
the hose would become brittle before they could make much progress on
the job.  They often left contaminated equipment and tools in the room,
rather than trying to decon them, and over time all the plastic parts
would break down and sift down to the floor.  

And that wasn't the scariest job they told us about. 

-----Original Message-----
From: radsafe-bounces at health.phys.iit.edu
[mailto:radsafe-bounces at health.phys.iit.edu] On Behalf Of Ferguson,
Dennis
Sent: Thursday, November 04, 2010 8:54 AM
To: 'The International Radiation Protection (Health Physics) Mailing
List'
Subject: Re: [ RadSafe ] Plastics and radiation exposure

I remember of two instances at TMI-2 that may apply. I tend to concur
with Cary.

The first was a lexan shield cover over a drain in a high beta area: the
clear plastic took on a smoky hue. Looked like what you get if you blow
cigarette smoke through a handkerchief. Exposure time was around a year,
I believe.

The other was the covering of a lead blanket over a bypass line root
where some of the accident debris was captured. It "burnt" in a
T-pattern (visible as a white area on the normally yellow blanket) which
was brittle when tapped with the end of a yardstick. Needless to say,
the blanket got replaced soon thereafter! It was there from shortly post
accident until sometime around 1983-4, I believe.

Dennis E. Ferguson | Radiation Protection Program Supervisor
Dept of Environmental Protection
Southcentral Regional Office
909 Elmerton Avenue, Harrisburg, PA  17110-8200
Phone: 717-705-4891   |   Fax: 717-705-4890  |  denferguso at state.pa.us
www.depweb.state.pa.us




-----Original Message-----
From: radsafe-bounces at health.phys.iit.edu
[mailto:radsafe-bounces at health.phys.iit.edu] On Behalf Of Cary Renquist
Sent: Thursday, November 04, 2010 11:39 AM
To: The International Radiation Protection (Health Physics) MailingList
Subject: Re: [ RadSafe ] Plastics and radiation exposure