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Crane Fell on Plutonium-Containing Spent Fuel Rods, Crushing Them
MSNBC reports that plutonium has been found in soil around the Fukushima plant:
The
Tokyo Electric Power Co., which operates the plant, said it found
three radioactive isotopes of plutonium — plutonium 238, 239 and 240 —
in five locations outside the plant in soil tests on March 21-22.
NHK
tv notes that a giant crane fell over and probably crushed spent fuel
rods at in Fukushima reactor number 3, which contain a plutonium-uranium mix:
(starting around 1:40 into video).
CNN points out:
Plutonium can be a serious health hazard if inhaled or ingested, but external exposure poses little health risk, according to the U.S. Environmental Protection Agency.
As the Argonne National Laboratory notes:
Essentially
all the plutonium on earth has been created within the past six decades
by human activities involving fissionable materials.***
Atmospheric
testing of nuclear weapons, which ceased worldwide by 1980, generated
most environmental plutonium. About 10,000 kg were released to the
atmosphere during these tests.Average plutonium levels in surface soil from fallout range from about 0.01 to 0.1 picocurie per gram (pCi/g).
Accidents and other releases from weapons production facilities have caused greater localized contamination.
So
like radioactive cesium and iodide - which I discussed yesterday -
plutonium doesn't exist in nature in any significant quantity, and so
"background radiation" is a meaningless concept.
Plutonium stays
radioactive for a long time. Pu-238 has an 88-year half-life, Pu-239 has
a 24,000-year half-life, and Pu-240 has a 6,500-year half life.
As I noted
yesterday, "internal emitters" (radioactive substances which get
inside our bodies) are more dangerous than "external emitters".
Plutonium is not that dangerous as an external emitter, but deadly as an
internal emitter.
As Argone National Labs notes:
When
plutonium is inhaled, a significant fraction can move from the lungs
through the blood to other organs, depending on the solubility of the
compound. Little plutonium (about 0.05%) is absorbed from the
gastrointestinal tract after ingestion, and little is absorbed through
the skin following dermal contact. After leaving the intestine or lung,
about 10% clears the body. The rest of what enters the bloodstream
deposits about equally in the liver and skeleton where it remains for
long periods of time, with biological retention halflives of about 20
and 50 years, respectively, per simplified models that do not reflect
intermediate redistribution. The amount deposited in the liver and
skeleton depends on the age of the individual, with fractional uptake in
the liver increasing with age. Plutonium in the skeleton deposits on
the cortical and trabecular surfaces of bones and slowly redistributes
throughout the volume of mineral bone with time.Plutonium
generally poses a health hazard only if it is taken into the body
because all isotopes except plutonium-241 decay by emitting an alpha
particle, and the beta particle emitted by plutonium-241 is of low
energy. Minimal gamma radiation is associated with these radioactive
decays. However, there is an external gamma radiation hazard associated
with plutonium-244 from it short-lived decay product neptunium-240m.
Inhaling airborne plutonium is the primary concern for all isotopes, and
cancer resulting from the ionizing radiation is the health effect of
concern. The ingestion hazard associated with common forms of plutonium
is much lower than the inhalation hazard because absorption into the
body after ingestion is quite low. Laboratory studies with experimental
animals have shown that exposure to high levels of plutonium can cause
decreased life spans, diseases of the respiratory tract, and cancer. The
target tissues in those animals were the lungs and associated lymph
nodes, liver, and bones.
NPR claims:
Although
plutonium is a long-lived emitter of radiation, it is also quite
heavy, so it is not likely to move very far downwind from its source.
However, plutonium from Chernobyl has been discovered in Sweden and Poland.
So
plutonium might be heavier than other radioactive materials, but it is
not so heavy that it can't travel hundreds of miles in the right
circumstances.
- advertisements -
My nephew has friend who is one; in fact he specializes in shutting down old plants. He got a lot of recruiter calls to go to Japan but is no longer considering it.
His name wouldn't be homer right?
funny fact:
Here in Europe, all the episodes are now screened to make sure there aren't any crude nuclear jokes in them that show carelessness... go figure. First it's funny untill it's not.
Instructions:
1. Put head in sand
2. keep doing it...
3. don't stop...
4. repeat number 1.
There are three major areas of employment for nukes. Power plants, radiation shielding and medical devices and nuclear weapons design.
Weapons is still a "flat" business since the cold war ended. Power Plants....well you know. Radiation shielding/detection and medical devices is the way to go as long as your name isn't in the .gov directory of trained nuclear workers (the Obama 2500 or so).
Or a fukushima plant operator.
...or one of 1000s of women named Millie Sievert.
...or one of 1000s of men named Mike Roe Sievert.
Are these guys ever going to catch a break?
Don't think so, the Guardian is reporting now that Reactor 2 is apparently in full meltdown with core apparently dripping down onto the concrete floor like radioactive molten lava, that can't be good.
The guardian article said that unit 2 is 'likely' melting down and the commentator speculated that it would be melting into the drywell, not "dripping down onto the concrete floor".
Re: Pu in soil samples
MSNBC must have an intern monitoring ZH, as this news item was posted yesterday by Monsieur Durden.
As least not as troubling as Pu in stool samples!
did you do the taste test?
"Tastes a bit nutty..."