Harry,
I am afraid that your complacency is quite wrong. Accidents to nuclear
reactors may be rare -- but when they occur they are disastrous.
I've tried to persuade you before that the standard of scientific and
engineering personnel employed by the nuclear industry is way below what it
should be. This is exemplified by the Fukushima disaster now going on in
Japan. The Japanese have had to call in experts from America and elsewhere
to help them. I've been watching BBC 24-hour News pretty closely during the
past week. Altogether, the BBC called in about 40 or 50 experts to explain
matter more clearly to the lay viewers. Not a single one of these has come
from the industry itself -- UK or US or anywhere else. They've all been
highly-knowledgeable people from academe or think-tanks. In the UK nuclear
industry, the engineering and scientific personnel are drawn almost
completely from one third-rate university with very low A-level (school)
entry requirements. The UK Government Nuclear Inspectorate hasn't ever been
able to recruit enough suitably qualified engineers and scientists, nor can
it do so today despite offering high salaries.
The long and the short of it is that, quite unlike any other industry --
repeat, any other industry -- relatively few engineers or scientists of
sufficient intelligence and qualifications would dream of risking their
careers to the day-to-day working of nuclear reactors. There are plenty of
other career opportunities for people of such calibre. No matter how
carefully nuclear reactors are designed, nor how well their equipment is
made, some mistakes -- no matter how infrequent -- can have the most
enormous consequences.
The main unforeseen mistake in the current case is that once spent fuel
rods are dunked in a tank of water and kept fairly separate then they are
assumed to be of no possible danger afterwards despite their residual
radioactivity. What was overlooked is that such spent fuel tanks oughts to
have had double -- and eve triple -- fail-safe sources of water. We don't
yet know whether they'll succeed in cooling down those fuel rods at
Fukushima. We don't yet know whether or not large quantities of caesium-137
with a 30-year radioactive half-lifetime are yet to be spewn over 30
million people in the Tokyo region of Japan only 100 miles away -- or even
to reach the coast of America. (If that were to happen I think you would
soon change your mind about nuclear power!)
The second fallacy in your line of thinking -- correlated with poor quality
of personnel -- is revealed by the fact that no insurance company in the
world would dream of insuring a working nuclear reactor, nor would any
nuclear construction company in the world dream of running reactors all
through their lifetimes and of having to decommission them afterwards.
Keith
At 23:35 18/03/2011 -0700, you wrote:
Thanks, Pete, I had forgotten about the CanDu reactors.
It's a long time since I spent time on nuclear reactors. I suppose I
considered the whole thing a done deal with little chance of much progress
in the US. There is apparently one under construction, but I don't know
where.
Important is the use of fuel that in due course won't be plentiful. Do the
CanDus use much of the fuel or only about a quarter? One day that will be
important. (I bet Canada is loaded!) You seem to indicate they use most of
the fuel, which is good. Also, your thorium point is something to watch for
= very interesting.
Do you know where the 'private' storage of spent fuel took place? I seem to
remember it was in Wisconsin or one of those other central northern states.
I also recollect they were offering storage space to other nuclear plants.
Certainly something should be done about the storage of spent fuel rods, but
the prospects aren't good considering how long the US government has been
dragging its feet.
Seem to remember that reprocessing plants don't have a good history. I think
that Jimmy Carter stopped a US plant. Windscale - the second disaster after
Chernobyl - was a reprocessing plant.
Harry
******************************
Henry George School of Los Angeles
Box 655 Tujunga CA 91042
(818) 352-4141
******************************
-----Original Message-----
From: pete [mailto:[email protected]]
Sent: Friday, March 18, 2011 2:21 PM
To: [email protected]; RE-DESIGNING WORK, INCOME DISTRIBUTION,
EDUCATION
Subject: Re: [Futurework] Question:
On Fri, 18 Mar 2011, Harry Pollard wrote:
> Ray,
>
> If Japan loses 40,000 people from this incident, it will be the worst.
>
> But the chance of that is small.
>
> Instead, spare a tear for the thousands of Japanese already lost from
> the natural events.
>
> The workers in the plants are suffering and will suffer, but the
> chance of further serious contamination of the civilian population is not
great.
> Anything might still happen, but the probability is that things will
> be soon under control and the main damage will be economic. I don't
> like the stories of spent fuel rods in temporary water tanks losing
> their water, but that's a continuing problem caused by various
> governments, including the US, fiddling around unable to provide them
> a permanent home. At least one nuclear plant got fed up with waiting
> and built above ground places (like a row of brick
> garages) for spent fuel rods. But, everywhere, in the absence of a
> safe place to get rid of them they sit in tanks of water. I would
> prefer them to be processed (against the law) and then suitably
> covered in concrete be dropped into the Pacific Trench
>
You don't want to either reprocess or dispose of spent fuel rods from
pressurized light water reactors (the only kind in the US). These "spent"
rods of enriched uranium contain 0.9% U235. Canadian "CanDU"
heavy water reactors normally use natural, unenriched uranium, which is 0.7%
U235. They can run happily with the "spent" light water rods, unreprocessed,
in fact with a slightly greater power output than normal.
And when rods are spent after running in a CanDU, they are really spent, but
they can still be processed further by running in a thorium reactor (except,
as a newly conceived technology, there are no commercial thorium reactors
yet in existence), which will lower the radioactivity content even further.
Upon final extraction from a thorium reactor, the rods can be potted in
glass and nested in gravel beds in tunnels dug deep in the geologically
inert canadian shield, at depths below the water table, and sealed in. These
will essentially be returned to the rock from which they were mined.
The existing CanDU reactors, by the way, are very close to the current
benchmark of "inherently safe", even though the design is
40 years old. The low activity level of the fuel means it can only achieve
criticality in a bath of heavy water, and while it does acquire residual
heat from daughter product decays continuing after shutdown stops the
fission chain, the larger size of the chamber reduces the heat density.
Further more, the individual rods are accessible outside the heavy water
envelope, and can be extracted one at a time to further dampen reaction. The
spent rods are thus not in a fixed geometry matrix (unlike the rod packs in
the GE design used in Japan), and thus are initially placed for cooling
storage in a lower density array, further reducing the heat load generated
during their cooldown period.
The Old GE design in Japan is referred to as "engineered safe", which is
PR-speak for "safe as long as all the engineered safety systems are working
properly". These devices should have been retired years ago.
-Pete
_______________________________________________
Futurework mailing list
[email protected]
https://lists.uwaterloo.ca/mailman/listinfo/futurework
Keith Hudson, Saltford, England http://allisstatus.wordpress.com/2011/03/
_______________________________________________
Futurework mailing list
[email protected]
https://lists.uwaterloo.ca/mailman/listinfo/futurework
