The Japan Syndrome

The Economist ^ | 15 Mar 2011 | The Economist

[gogogodzilla]

THE precise details of what has gone wrong at the nuclear power plants in north-eastern Japan following the magnitude 9.0 earthquake that struck the area on March 11th remain hazy. But a picture is beginning to emerge as events unfold and information is made available by the plants' operators and the Japanese authorities.

Start with the basics. Nuclear energy is produced by atomic fission. A large atom (uranium or plutonium) breaks into two smaller ones, releasing energy and neutrons. These neutrons may then trigger the break-up of further atoms, creating a chain reaction. The faster the neutron, the fewer break-ups it provokes. This is because an incoming neutron has to be captured to provoke fission, and fast neutrons are harder to capture. As a result, the chain reaction will peter out unless the neutrons can be slowed down sufficiently.

(snip)

So what happens when things cease to run smoothly, as when an earthquake interferes with the plant's systems? When designing reactors, engineers attempt to achieve what they call “defence in depth”. The idea is that if any specific defence fails, another will make good the shortfall. This is a principle that Fukushima Dai-ichi, the worst hit of the nuclear plants, has been testing to destruction. The defences have failed badly at all three of the reactors which were running at the time the earthquake hit.

Some defences are simply barriers. The pellets of nuclear fuel are encased in hard alloys based on zirconium (which lets neutrons pass freely through), to make fuel rods. The reactor core which includes these rods, and the water it sits in, are contained within a thick steel pressure vessel. That, in turn, sits within a larger steel structure, the primary containment vessel. Around all this sits the steel and concrete of the secondary containment structure.

[gogogodzilla]

I thought that this was probably the best summary of what has happened at the Fukushima nuclear power plant. They actually explained it all without hype or hyperbole.

[The_Media_never_lie]

Good post.

[Uncle Ike]

” explained it all without hype or hyperbole “

Batten down the hatches, FRiend - *explaining* without hype or hyperbole tends to make one unpopular here on FR, of late....

;)

[J Aguilar]

NHK TV is telling just that. It is the Western media the one that has gone mad.

[Vaquero]

the solution

[thecabal]

Gee, with your handle, I would think that you would be cheering the destruction of Japan. /s

[DB]

Excellent report.

All the hyperbole going both ways would be greatly attenuated if the Japanese government didn’t leave such a large information vacuum to be filled by others - others that don’t know the actual facts...

[Pontiac]

[Graybeard58]

Now perhaps someone from the media can explain the Richter scale to the masses and quit playing fast and loose with numbers. The quake has been variously reported as 8.9.,9.0 and 9.1, as if there is very little difference in those numbers, when in truth, there is a major difference in those numbers.

There is a very good article explaining it here:

http://earthquake.usgs.gov/learn/topics/richter.php

[pieceofthepuzzle]

If this is accurate it doesn’t make sense to me that they would have spent fuel rods, that have the capacity to do the damage that they are apparently doing now, stored in pools several stories up from the bottom of the containment building, and outside of any primary containment structure. Seems like you’re just asking for trouble doing that.

[DaxtonBrown]

[If this is accurate it doesn’t make sense to me that they would have spent fuel rods, that have the capacity to do the damage that they are apparently doing now, stored in pools several stories up from the bottom of the containment building, and outside of any primary containment structure. Seems like you’re just asking for trouble doing that.]

Wait till you figure out that because Harry Reid stopped Yucca Mountain, we have dozens of such pools all over the US.

[Pontiac]

These plants are a very old design. At the time they were built it was expected that plants would only store spent fuel on site for a very limited time. After about a year the fuel would be cool enough to be shipped off to a permanent burial site.

Newer plants have the spent fuel pools in bunker like buildings. Fuel is never stored in the reactor building.

By the way Fukushima Dai-ichi does have a Spent Fuel Storage Building that is shared by all of the plants on the site.

[Larry Lucido]

But there’s a plume! A bloomin’ plume!!

:-)

[thackney]

In Japan, they reprocess their spent nuclear fuel. It greatly reduces the need for long term spent fuel storage.

[Tribune7]

It's a good article. It kind of backs up what Barry Brook said a few days ago.

This set of events is often referred to as a meltdown, though the word is not recognised as a term of art by the nuclear industry or its regulators.
So far, this most dramatic turn of events has not come to pass. The levels of radioactivity recorded around the site are high, but are unlikely to do great harm beyond it. Unlike Chernobyl, there is no obvious mechanism for spreading the damage at Fukushima Dai-ichi, though there could be further explosions if, on melting, the red-hot fuel hits a body of cold water and vaporises it explosively.

And

If no further harm is done, an amount of damage comparatively small when set against the many thousands of lives lost across all affected areas might be seen as a victory—but hardly one to celebrate.

[Pontiac]

That is true but at the time of the design of these plants reprocessing was not considered. Reprocessing was only done for the purpose of collecting plutonium for bombs. Commercial plant fuel was not considered worth reprocessing for that purpose.

[Conservative Vermont Vet]

Among the problems was the fact that crucial electrical switching equipment was in a basement, and therefore got flooded.

Huh? WTF?

The "best and brightest" minds from Japan and GE did NOT foresee that this (in flood/Tsunami-prone Japan) would be the WORST possible place to locate "crucial electrical equipment???

Likewise, why were this plants not surrounded by 30-50 foot high and extra thick, concrete walls which would alleivate any such problems?

Is common sense and logic in short supply in Japan and from the US (GE) Engineers?

NEXT IS THIS:

"The problem is that the power for the cooling system was cut off when the earthquake hit. Then the backup diesel generators were knocked out of commission by the tsunami. Backup batteries could keep the cooling system going for only about eight hours more. The plant's operator tried to bring in mobile generators to restore power, but the connections reportedly didn't match up."

DIDN'T "MATCH UP?"

Double, WTF!!!

Something I have not seen discussed (though possible I may have missed it) is that acccording to reports, that after the backup generators failed, others brought in could not be used due to a (beyond stooopid) issue of their not being compatible and thus could not be connected.

(Have we not been informed that EVERY possible contingency had been considered and multiple "redundancies" were built in? Guess that one was somehow, overlooked!)

This appears to be something (Generators) that we (or any number of other countries) could have furnished Japan?

Likewise what I also have not seen is the reason why a simply "cut and splice" could not have been jerry-rigged to allow any generator to be used?

There remains many unanswered questions, but some of us neophytes (though tinkerers) keep wondering why some of the best minds in the world could not find some means to overcome what appears to have been something any journeyman e1ectrician could have hooked up?

[thackney]

Reprocessing of Uranium started in 1943. The original facilities were for nuclear weapons. When these plants were built, it was certainly planned that the spent fuel would be reprocessed, not accumulated.

[thackney]

From 1969-90 there were more than 160 shipments of used nuclear reactor fuel from Japan to Europe.

Reprocessing of the Japanese used fuel has been undertaken in UK and France under contract with Japanese utilities.

http://www.world-nuclear.org/info/default.aspx?id=458&terms=reprocessing

[gogogodzilla]

Good questions. Though I'd say that the more specialized the field and training, the easier it is to forget that one has to still plan for the basics.

About 15 years ago - back in my college days, I had a friend who was a brilliant mathematician but could not ever remember that he had to pay rent on his apartment to keep from being evicted or that he had to pay for his electricity or else it'd be cut off.

That said, it's quite possible that when the generators where bought, they did match up to the specs of the time... but then over the years, the company upgraded the facilities, but forgot to upgrade the generators to match.

Though, all this is speculation on my part.