Not only the Air Force has used Sr/Y 90 paint. It was also found on
radio sets (R 108 and R110/GRC) of the army (1961). These sets were manufactured
by a firm in Brussels. The paint was used just like radium, promethium,
tritium (and sometimes thallium) paint: for luminescence purposes.
Problem with this paint was that a high specific activity was needed to
get the required amount of luminescence. Reports mention 0.82 gram Sr 90
(as sulfate) per gram paint (=120 mCi/gram).
Because the paint was applied directly on the knobs, the Sr/Y 90 paint
was an open source, being equally radiotoxic to Ra-paint (both because
of the high-energy beta radiation as because of the risk of internal contamination).
All these knobs were disposed of as radioactive waste.
I also recall a Sr/Y 90 contamination case on former Navy material (wooden US mine sweepers from the Marshall plan?) sold to a scrap company that removed all old markers, thus spreading paint all over the ship.
Although the use of Sr/Y 90 paint has never become as wide spread as radium or tritium paint, it is certainly something to take into acount when screening historical items.
One addition to avoid misunderstanding: there is also a non-radioactive strontium paint (Sr indeed, but no Sr/Y 90!) used on air planes (nowadays). This is a strontiumchromate paint, used as a component in the basic paint layer. As this chromate is known to cause cancer. Although people are looking for alternatives, as far as I know a product with equal protection qualities fit for use in a very harsh environment like that on the outer plating of planes has not been found yet.
With kind regards,
Jetty Middelkoop
Radiological Protection Service
Netherlands Ministry of Defence
James Reese wrote:
I heard an interesting story today from a friend of mine regarding the use
of Sr/Y 90 as an additive in paint used on aircraft in the Air Force. He
did not know the reason that Sr/Y was used or how much was added to the
paint.Has anyone else heard of the Air Force using Sr/Y 90 as a paint additive?
If so, why was it used and in what concentrations? Was there sufficient
quantities to create contamination concerns when the paint was removed?James H. Reese
Health Physicist
(916) 689-2680 tel.
(916) 689-6270 fax
james.reese@worldnet.att.net************************************************************************
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