Pressure Buildup in PuBe Sources

["Robert R. Milwicz" <milwicz@arundel.Princeton.EDU>]

The story as I was told in regard to the pressure build up is as
follows:

In welding the original sources, the welders did not wait for the
sources to cool to room temperature. They dunked them into water.
Water entered the sources through the openings that existed in the
weld at the high temperature. When the source cooled the opening
sealed. Wipe test showed no leakage, the source was fine. That is,
until the water dissociated from the radiation built up gas pressure
and caused the side of the right cylinder to bulge out. One
unfortunate person had trouble putting a source into his well
logging device because it would not fit so he put in on a lathe to
turn it down and it exploded causing him to have a lung lavage.
Subsequently the sources were recalled by Mound and recanned.

And that is the story as I recall it and buried in my pile of 30 year 
old reference materials is more on the subject as well as my own data 
on measuring several PuBe sources years after the recanning operation 
to make sure they were not putting on girth in their middles.
Right now I am glad ours were sent to Los Alamos under the recall 
program last year.

Speaking of water here is an interesting meter story. A researched 
called me to ask me to check her Ludlum Model 3. She said it  did not
operate after it was first turned on in the morning. She had to leave it
on before it would work properly. I opened the case and found that
about 20 ml of water was 
inside. How did it get there. Here in New Jersey as some of you know, 
we have very humid days. The meter was used in the lab and also in a 
cold room. It went between both often. It was summer when the 
meter was found to be malfunctioning. 
My theory is that taking the meter between a very warm humid 
environment and the cold room caused the not too well sealed meter to 
absorb water and it condensed inside. Like you bathroom mirror after 
you teenage kids take a shower.

BOB Milwicz

************************************************************************
The RADSAFE Frequently Asked Questions list, archives and subscription
information can be accessed at http://www.ehs.uiuc.edu/~rad/radsafe.html