tritium, random comments

[Les Slaback <lester.slaback@nist.gov>]

In a previous life I tried to force tritium from steel (i.e., decon it).  I
was totally unsuccessful.  The release rate under various physical assaults
(heating, ultrasonics, chemicals) was a small fraction of the inventory.
You might the surface down but it oozes out of the pores again very quickly.

On the other hand other materials readily give it up, e.g., tungsten.
[Asserted on the basis of one decon test via heating.]
A current project indicates the release 'halflife' for tritium oxide in
aluminum in contact with water is on the order of 2-4 weeks.
Clearly it depends upon perspective.  If you are trying to decon something
you are usually dealing with long retention times.  If you are trying to
contain it, good luck!

Some materials, e.g., uranium, hold on to hydrogen rather well.  But that
opens another can of worms.
All in all, tritium is a verrry interesting radionuclide.
Disclaimer:  the above are the personal musings of the author, and do not
represent any past, present, or future position of NIST, the U.S. government,
or anyone else who might think that they are in a position of authority. 
Lester Slaback, Jr.  [Lester.Slaback@NIST.GOV] 
NBSR Health Physics 
Center for Neutron Research 
NIST
100 Bureau Dr.  STOP 3543 
Gaithersburg, MD  20899-3543 
301 975-5810 
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