[Milsurplus] TBY radiation

[Dennis Monticelli]

We have several TBY's at our museum. I will pass along a brief summary of
our findings in the hope that collectors will find it useful.

Radiation (off the face) was measured with several different calibrated
instruments.  They are indeed hot, especially the latter models (TBY-8
hotter than TBY-1).  The OSHA allowed personal radiation dose is easily
exceeded if one were to be within a few feet of the faceplate for a period
of many hours.  Of greatest concern is particulates that may be inhaled or
else transferred to the mouth or eyes via hands.  If you look closely at
the lettering with a magnifying glass you will notice that the surface is
not smooth, but sponge-like.  Alpha particles have broken up the paint
structure leaving that surface material friable.  Within the body alpha,
beta, and gamma are all of concern....especially alpha.  At distance the
radiation species of concern is mostly gamma as alpha doesn't travel far at
all and beta doesn't penetrate the skin very far.

OSHA allowances for non-occupational individuals are quite low in terms of
both rate and total annual dose.  It's easy to exceed them with a CAT
scan.  However, occupational allowances are 50 times higher!  No, military
collectors are not an official occupational category :-)

Bottom line is to use caution with TBY's.  A clear coat over the front
panel and tuning drum lettering would go a long way to mitigating the most
dangerous situation....particles lodging in the body.  As for the beta and
gamma:  Well, an 1/8" of aluminium blocks most of the beta but in order to
stop the gamma it takes sheet lead or thick leaded glass, both of which are
commercially available with the latter being pricey.  Otherwise, keep at
least 3 feet away if you're going to be near a TBY for many hours.
Remember that radiation falls off as the square of distance. That
translates into budgeted restoration hours for collectors that have to get
very close for their work.  And please don't use compressed air on them
without being well out in the open and wearing a mask.  Best to not use
compressed air at all.  Finally, I would suggest that TBY's be long-term
stored in a bag in order to contain particulates.

I am not aware of any radiation induced health issues among the code
talkers, but that doesn't mean it didn't happen.  We all know about the
terrible situation of the ladies that brushed on Radium 226 infused paint
(direct ingestion).  Knowledge of radiation effects on the body only grew
in the decades following WW2.  Today, the area of most concern is the
increased usage of medical scans.

Dennis AE6C
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