Thermal Protection of Titanium Tritide Foils

[avrel@gemini.oscs.montana.edu (Erick Lindstrom)]

Radsafers:

A professor here has been developing his own (ECD) detector cells for many
years.  Foil temperature protection has primarily been accomplished through
the use of bi-metallic snap switches.

A condition in MSU's recently renewed license states "...detector cells
containing titanium tritide foil or scandium tritide foil shall only be used
in conjunction with a properly operating temperature control mechanism which
prevents the foil temperature from exceeding that specified by the
manufacturer and approved the U.S. Nuclear Regulatory Commission..."  The
NRC approval condition was not in our old license.

This researcher wants to purchase a new TT foil.  The manufacturer of the
foil (Safety Light Corp.) says the temp must stay below 200 C (which is much
higher than the operating temp we need).

My problem here lies in the NRC approval.  Are there any specifically
"approved" manufacturers of thermal control mechanisms for these types of
applications?  Additionally, what (if any) alternatives to the snap switch
exist?

Thanks for your help!

-Erick

 Erick Lindstrom
 Radiation Safety Officer
 309 Montana Hall
 Montana State University
 Bozeman, MT  59717-0244
 Phone: (406) 994-2108
 Fax:	 (406) 994-4792
 avrel@gemini.oscs.montana.edu