Radioactive SparkPlugs

[WALKIEWICZ@edinboro.edu]

RADSAFERS:  I have in my possession a spark plug in its original container
which was made by Firestone (now Bridgestone/Firestone), and which is
advertised as having "...Polonium (Radioactive) Electrodes..."

The insert claims:	Smoother Motor Performance
			Give Faster Pick-Up
			Provides Quicker Starting
			Save More Gasoline

The patent covering this spark plug was issued on Aug. 6, 1929 to Alfred M.
Hubbard (it was filed on February 11, 1924) and assigned to Radium Spark Plug
Corporation.  The patent discusses the use of "...radium for ionizing the
space between said terminals...... Hence, instead of the short interval of
one-thirty-second of an inch..., which normally obtains..., I provide a much
greater space.  Said space may be one-fourth inch...or more.  ....... Thus,
I provide for a much longer exposure of the fuel to the ignition spark, ......
This results in providing for a more complete combustion of the fuel in a
much briefer period of time... and also the more nearly complete elimination
of all the unburnt fuel left in the cylinder..."

Upon moving corporate headquarters to Nashville, archived materials were
donated to the University of Akron.  Examination of documents showed that
Spark Plugs with Polonium (Radioactive) Electrodes were advertised in Firestone
consumer catalogs beginning in Spring, 1940 and at least through Fall, 1946.
The ads claimed "Money-Back Guarantee.  Your car will start quicker and run
smoother or your money refunded."  The cost was $0.59 per plug.  It was also
interesting to see Fiestaware beginning to be advertised in the 1942 catalog
at $1.25 for a seven piece set (6 tumblers and a pitcher).

I wonder what the "shelf-life" was for these plugs, assuming that Po-210
was used, with a half-life of 138 days!  I did take a gamma-spectrum with
a 3"x3" NaI detector and can easily observe a Radium-226 spectrum with an
activity very roughly of several nanoCuries.  This is probably just an
impurity left over from however the polonium was separated.

I would appreciate receiving ANY information about radioactive spark plugs,
either via this list or privately: walkiewicz@edinboro.edu
even anecdotal information would be useful, eg. does ANYONE even remember
the use of such a product?

The only information I could get from NRC was a copy of a 1956 AEC Amendments
of Byproduct Material Regulation, which listed "static elimination device" and
"ion generating tube", each of not more than 500 microcuries of Polonium 210
per device.  My "guess" is that Firestone stopped manufacturing such spark
plugs after the AEC came into existence with regulations concerning the use
of radioactivity in consumer products.

Thanks in advance for any help or insights.

Tom Walkiewicz			walkiewicz@edinboro.edu
Dept. of Physics (&RSO)		http://www.edinboro.edu/~Walkiewicz/home.html
Edinboro University		office: (814)732-2468
Edinboro, PA 16444