Re: H-3 signs behaviour in a fire

[SBD <sbd@co.disp.mindef.nl>]

We too had the experience of a (short but hot) fire that completely turned
some gun sights to ashes. The betalights in the middle however still were
intact. They glowed in the dark and we did not detect any contamination.
Borosilicate glass is very high quality glass, being very temperature
resistant.
As these glass tubes too are melted at the end after filling them with
tritium, they too  melt at a certain temperature. However this temperature is
not known to me. Anyone out there who knows the melting point  of
borosilicate glass? This will be interesting info for fire fighters in case
of a fire involving exit signs.

Paul Lavely wrote:

> We had been "assured" by fire fighters that they had not seen a major
> fire in which these sign were not totally destroyed. I have only seen
> one post fire sign and it was a lump of solid charred plastic. I
> guess that some of the tubes could have been intact inside the lump.
>
> I plan to use the information you provided to work with local fire
> responders (who by chance have a HP Tech. now in fire protection) to
> do some post fire surveys.
>
> I agree that the dose from stepping on one of the tubes and releasing
> the H-3 would be a small dose - especially if they are wearing
> typical fire-fighting gear.
>
> Paul Lavely <lavelyp@uclink4.berkeley.edu>

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