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Rich Grise[_3_] Rich Grise[_3_] is offline
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Default History of Nuclear Disasters

DoN. Nichols wrote:
On 2011-03-19, Michael A. Terrell wrote:
"DoN. Nichols" wrote:

It's twin, the SM-1A was across the street from my barracks at Ft
Greely, AK. It was decommisioned and encapsuled in concrete, on site.

http://en.wikipedia.org/wiki/Army_Nuclear_Power_Program has a photo
about half way down, on the right side of the page.


Yep! and the SM-1 was certainly the first which I had wondered
about. (I mean a security compound within a security compound after all.
:-)

The other I mentioned turns out to be the MH-1A -- also shown in
the collection of photos on that Wikipedia site. I -- never knew its
designation either. And it appears to still be functional.

With two reactors, no wonder we had those radiation drills. The
never told us why (of course), just to do it.

Here's a little item to **** off both extremist sides of the "debate":

A transcript from
http://www.freedompolitics.com/news/...ety-power.html
"Article from the Carnegie Endowment

Written by James M. Acton

Original Article

Until March 11, with the 25th anniversary of the Chernobyl accident
approaching -- and memories of that disaster receding -- safety concerns no
longer appeared to be the killer argument against nuclear power they once
were. Instead, another fear, of climate change, looked like it might be
driving a "nuclear renaissance" as states sought carbon-free energy
sources. But the ongoing crisis at Japan's Fukushima Daiichi Nuclear Power
Station will return safety to the forefront of the nuclear power debate.
Even the most ardent industry advocates now recognize that the unfolding
crisis inside two reactors there -- shown on live television and beamed
around the world -- has left the future of their industry in doubt.

Nevertheless, the case for nuclear power remains strong. All forms of energy
generation carry risks. Fossil fuels, which (for the time being at least)
are nuclear energy's principal rival, carry the risk of catastrophic
climate change. And as we're seeing in Japan, we haven't eliminated all the
dangers associated with nuclear power, even though accidents are few and
far between.

Good public policy involves balancing these risks. Persuading the public to
accept the risks of nuclear energy will, however, not be easy. To do so,
the nuclear industry will have to resist a strong temptation to argue that
the accident in Japan was simply an extraordinarily improbable confluence
of events and that everything is just fine. Instead, it must recognize and
correct the deficiencies of its current approach to safety.

When it comes to safety, the nuclear industry emphasizes the concept
of "defense in depth." Reactors are designed with layers of redundant
safety systems. There's the main cooling system, a backup to it, a backup
to the backup, a backup to the backup to the backup, and so on. A major
accident can only occur if all these systems fail simultaneously. By adding
extra layers of redundancy, the probability of such a catastrophic failure
can -- in theory at least -- be made too small to worry about.

Defense in depth is a good idea. But it suffers from one fundamental flaw:
the possibility that a disaster might knock out all of the backup systems.
A reactor can have as many layers of defense as you like, but if they can
all be disabled by a single event, then redundancy adds much less to safety
than might first meet the eye.

This kind of failure occurred at Fukushima Daiichi on March 11. As soon as
the earthquake struck, the reactors scrammed: The control rods, used to
modulate the speed of the nuclear reaction, were inserted into the reactor
cores, shutting off the nuclear reactions. So far so good. Nevertheless,
the cores were still hot and needed to be cooled. This in turn required
electricity in order to power the pumps, which bring in water to cool the
fuel.

Unfortunately, one of the external power lines that was designed to provide
electricity in just such a contingency was itself disrupted by the
earthquake. This shouldn't have mattered because there was a backup. But,
according to a news release issued by the power-plant operator, the
malfunction in one external supply somehow caused off-site power to be lost
entirely.

Once again, this shouldn't have been too much of an issue. There was a
backup to the backup in the form of on-site diesel generators. And, sure
enough, they kicked in. Fifty-five minutes later, however, they were
swamped by the tsunami that followed the earthquake. From that moment on,
plant operators were in a desperate struggle to prevent core melting.

Japanese regulators are certainly aware of the danger of earthquakes; they
take safety extremely seriously. Like other buildings in Japan, nuclear
reactors must be able to withstand earthquakes. The problem, as we now
know, is that there is a significant chance of them falling victim to
events more extreme than those they were designed to withstand.

This problem was highlighted by the earthquake centered near the
Kashiwazaki-Kariwa nuclear power plant in 2007. The earth movements
generated by that quake were larger than the plant's design limit.
Fortunately, there was not a major accident; the safety systems worked as
designed in spite of the quake's physical impact. Before the plant could
reopen, however, new safety features had to be added to ensure that it was
capable of withstanding bigger earthquakes.

Of course, the issues raised by the 2007 and 2011 earthquakes are relevant
to the whole world -- not just Japan. What is needed now is a sober and
careful assessment of what engineers call the "design basis" for all
nuclear power plants worldwide -- those already in operation, those under
construction, and those being planned. Specifically, we need to determine
whether they are truly capable of withstanding the whole range of natural
and man-made disasters that might befall them, from floods to earthquakes
to terrorism.

Even after the ongoing disaster in Japan, the nuclear industry is unlikely
to welcome such an exercise. It is almost certain to argue that a
whole-scale reassessment is unnecessary because existing standards are
adequate. But after two earthquakes in less than four years shook Japanese
reactors beyond their design limits, this argument is simply not credible.
It is also self-defeating.

For nuclear energy to expand, the public must trust the nuclear industry. It
must trust reactor operators to run their reactors safely. It must trust
regulators to ensure there is adequate oversight. And, most importantly
perhaps, it must trust reactor designers to create new reactors that do not
share the vulnerabilities of older ones.

This last point is crucial. New reactors, with enhanced safety features,
would almost certainly not have befallen the same fate as those at
Fukushima Daiichi, which is four decades old. Convincing the public of this
argument will be extremely hard now, however.

After Chernobyl, the nuclear industry argued that -- as far as safety was
concerned -- Soviet RBMK-type reactors, like the one involved in the 1986
accident, had about as much in common with modern Western reactors as an
inflatable dinghy does with an ocean liner. And they were right. But their
argument made very little impact because the nuclear industry had lost the
public's trust.

It is vital the nuclear industry does not make the same mistake now. It must
not try to sweep safety issues under the carpet by telling people that
everything is OK and that they should not worry. This strategy simply won't
work. What might work is to acknowledge the problem and work to fix it."