Re: yet more nuclear fuel industry accidents..."pure good fortune nobody dangerously contaminated"


TD wrote:
"abelard" <abelard2@xxxxxxxxxxx> wrote in message
news:fhmmv156u2b8843jcvd7l0kqmfkolii8qp@xxxxxxxxxx
On 21 Feb 2006 08:08:43 -0800, "Herbie Moon Glow" <goliethslayer@xxxxxxx>

typed:

A N O'Nymous wrote:

<snip>
12) Iridium-192

I believe it is an isotope of platinum.

don't be dippy...

<snip>
16) Americium-241

Another form of Plutonium...

you're being dippy again...

Mr Glow should probably have another look at his Periodic Table.



TD, read this; you might learn something -- if you can learn anything
at all! Otherwise, please just shut up because like Abelard you are
just plain stupid!


Americium -- The Basics

Americium (chemical symbol Am) is a man-made radioactive metal, with
Atomic Number 95. The most important isotope of Americium is Am-241.
Americium (isotope Am-241) was discovered by nuclear chemist Glenn
Seaborg and his colleagues at the University of Chicago in 1944.

Americium is a man-made metal produced when plutonium atoms absorb
neutrons in nuclear reactors and in nuclear weapons detonations.
Americium has several different isotopes, all of which are radioactive.
The most important isotope is Am-241.

Americium is a silver-white, crystalline metal that is solid under
normal conditions. All isotopes of americium are radioactive.
Americium-241 primarily emits alpha particles, but also emits gamma
rays. A mixture of americium-241 and beryllium emits neutrons.
Americium-241 has a half-life of 432.7 years.

Americium-241 is the only isotope of americium to have widespread
commercial use. It is the radiation source for a number of
applications:

* medical diagnostic devices
* research
* fluid-density gauges
* thickness gauges
* aircraft fuel gauges
*distance-sensing devices, all of which utilize its gamma
radiation.

A mixture of americium-241 and beryllium provides a neutron source
for industrial devices that monitor product quality. Two examples are
devices for nondestructive testing of machinery and gauges for
measuring the thickness of glass and other products.

But, by far the largest and most widespread use of americium-241 is
as a component in household and industrial smoke detectors, where a
small amount is used in an ionization chamber inside the detector.

Ionization Technology Smoke Detectors
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Exposure to Americium

Most americium-241 in the environment originates from the
atmospheric testing of nuclear weapons during the 1950's and 1960's.
The exposure to an individual from it is very, very small.* Facilities
that produce weapons and manufacture smoke detectors are minor sources
of Americium-241 contamination. Americium-241 may also enter the
environment if industrial americium sources (many of which are
portable) are lost or stolen, and subsequently broken open, or melted
in a steel mill. Also, when household smoke detectors are discarded,
they go directly to municipal landfills, including any Am-241 they may
contain.

*While most of the shorter-lived radionuclides have now decayed
away, longer-lived radionuclides such as americium-241 will remain in
the environment for many years. However, since they decay slowly, they
emit radiation slowly, so the dose is very low and will decline. In
1987, the National Council on Radiation Protection and Measurements
estimated that the combined annual effective dose equivalent to an
individual from the radionuclides remaining is less than one mrem per
year. Details of the study are reported in NCRP Report No. 93, Ionizing
Radiation Exposure of the Population of the United States.

Americium-241 is an unstable (radioactive) isotope with a half-life
of 432.7 years. As it decays, it releases alpha and gamma radiation and
changes into neptunium-237, which is also radioactive. The
americium-241 decay chain ends with bismuth-209, a stable
(non-radioactive) element.



Exposure to any significant amount of Am-241 is unlikely under normal
circumstances.

People may be directly exposed to gamma radiation from
americium-241 by walking on contaminated land. They may also be exposed
to both alpha and gamma radiation by breathing in americium
contaminated dust, or drinking contaminated water. Because
americium-241 was widely dispersed globally during the testing of
nuclear weapons, only very minute amounts of it are found in the soil,
plants, and water. Living near a weapons testing or production facility
may increase your chance of exposure to americium-241.

Smoke detectors containing Am-241 also provide some radiation
exposure. However, the radiation exposure people receive from a smoke
detector is very low. The health risk reduction from the fire
protection vastly outweighs the health risk from the radiation. That
said, you should still handle smoke detectors containing americium with
care. To avoid exposure:

* never dismantle a smoke detector
* never burn a smoke detector in your fireplace
*check with your local fire department for safe disposal
procedures.


People who live or work near a contaminated site, such as a former
weapons production facility, may ingest americium-241 with food and
water, or may inhale it as part of resuspended dust. Once in the body,
americium-241 tends to concentrate in the bone, liver, and muscle. It
can stay in the body for decades and continue to expose the surrounding
tissues to radiation, and increase your risk of developing cancer.

When inhaled, some Am-241 remains in the lungs, depending upon the
particle size and the chemical form of the americium compound. The
chemical forms that dissolve easily may pass into the bloodstream from
the lungs. The chemical forms that dissolve less easily tend to remain
in the lungs, or are coughed up through the lung's natural defense
system, and swallowed. From the stomach swallowed americium may
dissolve and pass into the bloodstream. However, undissolved material
passes from the body through the feces.


Health Effects of Americium

Americium-241 poses a significant risk if ingested (swallowed) or
inhaled. It can stay in the body for decades and continue to expose the
surrounding tissues to both alpha and gamma radiation, increasing the
risk of developing cancer. Americium-241 also poses a cancer risk to
all organs of the body from direct external exposure to its gamma
radiation. One source of direct exposure would be contaminated soil.
Exposure to any significant amount of Am-241 is unlikely under normal
circumstances. ("Normal circumstances" do not include trying to access
or remove the Am-241 source in a smoke detector!)

(Source the U.S. EPA)

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