Latest Q&A On Fukushima
With so much changing in Fukushima on a daily basis, it is easy to lose track of what is happening on any given day. In fact, some like Zero Hedge are now weary of reporting Fukushima news due to expectations of a full detraction within half an hour or so, after someone is discovered to have no idea what a decimal comma is, or another is simply lying, in ongoing efforts to spread confusion. Which is why the following Q&A from Reuters on the latest situation in the radioactive power plant is a useful recap for virtually everyone, even though most likely the party line, not to mention "fact" will change shortly.
WHAT IS HAPPENING?
struggling to restart the cooling pumps in four reactors damaged by the
9.0 magnitude earthquake and tsunami and later drenched from desperate
hosing operations to keep the reactors cool.
challenge is to pump out radioactive water flooding the basements in
reactors No.1, No.2 and No.3 and hampering the restoration of
electricity to continuously power the cooling pumps.
reactor has posed especially nasty risks, emitting high levels of
radiation at more than 1,000 millisieverts an hour in both the water and
air in the basement of the turbine building. That is the highest
reading seen in the crisis and compares with a national safety standard
of 250 millisieverts over a year. This most likely means that byproducts
from a partial meltdown in the reactor core are leaking out into the
In the No.1 reactor, workers have been able to start
running a circulatory steam condensing system to begin to clear
contaminated water. But after five days of pumping, there is no clear
indication of significant progress.
The same systems in reactors
No.2 and No.3 are flooded and so need to be emptied before they can
handle the contaminated water. TEPCO has said it may need to think out
of the box to clear the dangerous waters, while preventing further flows
into the sea and soil.
HOW LONG MIGHT THIS TAKE?
Nobody knows. The most likely scenario is a long, drawn-out fight, with
incremental progress interrupted by emergency cooling measures and
spikes in radioactivity.
Once the pumps and the residual heat
removal systems are running, it would take only a couple days to bring
the reactors to a cold shutdown. But engineers are literally working in
the dark. Lights have only recently gone on in the control room, but
electrically powered monitors and gauges -- workers' eyes and ears
inside the reactor -- are still off. Radiation readings outside the
reactors are still taken via a moving car, because the monitoring posts
are not powered. Temperature and pressure readings from backup systems
are all that workers have to "see" what is going on in the reactors.
Workers remain hampered by broken pipes, debris, flooded equipment and a
scarcity of replacement pumps and water tanks. Work has also been
interrupted by hosing operations to lower rising temperatures in the
reactor cores and spent fuel pools, as well as by an occasional fire and
Because of the high levels of radiation in
the water, experts suspect damage to the containment structures around
the No.2 reactor core. They said it may take as long as a few months to
bring that reactor to a cold shutdown.
WHAT ARE THE RISKS?
The main risk comes from the radiation that will continue to seep, or
burst, out each time a pipe leaks or rising pressure forces workers to
vent steam. Leaking water from within the nuclear pressure vessels could
find their way into the soil and the ocean, while spikes in radiation
could contaminate crops over a wide area.
The risk that the
spent fuel pools could reach recriticality seems remote, as long as
there are workers and firefighters willing to douse the reactors with
water each time temperatures start to rise.
The same could be
said of a small, hypothetical risk of a corium steam explosion,
particularly in the No.1 reactor, which is the plant's oldest and which
is believed to have a weak spot. If workers are unable to continue
hosing operations, and if the nuclear fuel manages to melt through the
bottom of the reactor and fall into a water pool below, this would
result in a high temperature burst and a sudden release of a huge amount
of hydrogen that could, in an unlikely "perfect storm" scenario, breach
the containment vessel.
Should either worst-case scenarios
happen, it could disperse high levels of radiation up to 20 km (12
miles) around the site, making it impossible to bring the reactors to a
cold shutdown without great sacrifice.
WILL THE SITE BECOME A NO-MAN'S LAND?
Most likely, yes. Even after a cold shutdown there is the issue of
tonnes of nuclear waste sitting at the site of the nuclear reactors.
Enclosing the reactors by injecting lead and encasing them in concrete
would make it safe to work and live a few kilometres away from the site,
but is not a long-term solution for the disposal of spent fuel, which
will decay and emit fission fragments over several thousand years.
The spent nuclear fuel in Fukushima has been damaged by sea water, so
recycling it is probably not an option, while transporting it elsewhere
is unlikely given the opposition that proposal would bring.
WHAT RISK FROM PLUTONIUM?
Plutonium has been found in soil samples at the site, further evidence
that fuel rods in at least one reactor may have melted down considerably
before they were cooled, and that there is damage to the structures
containing the nuclear core.
Only trace amounts of the toxic
substance have been detected. The level of up to 0.54 becquerals per kg
of soil is not considered harmful. Most people have some plutonium in
their bodies from atmospheric and underwater nuclear tests and some
pacemakers are powered by plutonium.
But the presence of the
radioactive poison outside the reactors compounds worry for the workers
there as long as authorities are not sure how the heaviest of primordial
elements leaked out.
Plutonium-239, used most in reactors, has a
half-life of 24,200 years. It is not readily absorbed by the body but
what is absorbed, stays put, irradiates surrounding tissue and is
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