radiation damage in teflon

["Minnema, Douglas" <Douglas.Minnema@ns.doe.gov>]

Dear RADSAFErs,

As many of you know, there was an event at Los Alamos in March involving a
release of Pu-238 from a vacuum line associated with a glovebox.  One
contributing cause was a degraded teflon seat in a valve in the vacuum line.
As a result, DOE is reviewing the overall application of teflon products in
our nuclear facilities.  

There are multiple issues involved in this problem, due the particular
environment that the valve was in.  Therefore, I will need to start sorting
out the various components that could have led to the degradation.
Radiation is an obvious one, but there was also the potential for mechanical
abrasion, thermal damage, and long-term exposure to an oxygen-deficient
environment.  Any one of these could have been the culprit, or more likely a
combination.

I am in the very early stages of beginning to look at the susceptibility of
teflon products to alpha radiation damage.  As many of us know, teflon is
very susceptible to damage from radiation in general, but most of the past
studies that I have found so far only discuss gammas, X-rays, and neutrons.
However, I need some specific technical information regarding alpha-induced
damage.  Anybody got any good references or contacts?

Please contact me directly at the address below.  Any help would be
appreciated.

Thanks,

Doug Minnema, PhD, CHP
Radiological Control Program Advisor for Defense Programs
National Nuclear Security Administration, US DOE

<Douglas.Minnema@ns.doe.gov>

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