RE: Source Expiration Dates

["Vernig, Peter G." <Peter.Vernig@med.va.gov>]

I would just like to say, I am interested in hearing remarks on this too.  I
have noticed that LSC calibration sources used to have expiration dates of
10 years past the calibration date and the new ones I've seen from Beckman
have 5 year expirations.  We have continued to use them.  I did retire some
where the labels had become obscured and where the glue holding the metal
caps in place had deteriorated.  These types for those that aren't familiar
with them are typically a small amount of material in a LSC vial that is
glass and flame sealed.  A metal cap is glued on to give a configuration
similar to a standard LSC vial with screw cap.  The ones that had to be
retired were all well past their  expiration dates.  It would seem a visual
inspection could take care of those problems.  Most common are C-14 and H-3.
H-3 has a 12.25 y half life, so at some point the activity deteriorates to
the point where the statistics are not acceptable.  If the scintillation
fluid deteriorated one would think it would become apparent.

Anyway if anybody chooses to respond to the original message privately, I'd
like to hear your thoughts too.

Peter G. Vernig
Radiation Safety Officer
VA Medical Center, Denver

1055 Clermont Street, Denver, CO 80220
ATTN:  RSO, Mail Stop 115
peter.vernig@med.va.gov
303-399-8020 ex 2447
FAX 303-393-5026

Any opinions expressed in this message are solely my own and do not
necessarily reflect the opinion or policy of the Denver VA Medical Center,
The Dept. of Veterans Affairs, or the U.S. Government.

"You win some.  You lose some.  And some get rained out."  Y. Berra

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