Re: Tritium stack sampling

[WOODM@crl.aecl.ca]

The standard way to sample elemental tritium from a stack is to simply use a
catalyst to oxidize the HT and then collect it as HTO with water bubblers.  

A typical sampler consists of a pair of water bubblers (for tritium oxide) 
followed by a catalyst (ie copper oxide bed @400C) and a second set of bubblers
(for the elemental tritum which has just been oxidized).  For low level 
sampling the bubblers are replaced with desiccants (ie: DRIERITE, mole sieve,
etc.)  With desiccants the sample is not dilluted by the sink (H2O in the case 
of the bubblers) and therefore a lower detection limit can be obtained.   There
is many variations on this arrangement.  To many to elaborate on hear.
  
Since there is a significant difference in the DAC for elemental and oxide forms
of tritium it is worth while having a two stage system to determine the HTO and
HT components.  People are often surprised by the amount of HTO they have!  

For an up-to-date overview of tritium sampling you may want to check out:

Tritium Sampling and Measurement. Health Physics vol 65, No 6, 
December 1993,  pp 610-627.

I have many other references for specific samplers. 
Contact me directly if you would like further information or just to discuse 
your sampling options.

Mike Wood
Radiation Biology and Health Physics Branch
Chalk River Laboratories
Chalk River Ontario.
Phone:613-584-8811 (4750)
FAX:613-544-1713
E-mail: woodm@crl.aecl.ca