Japan Radiation: Dangers to the Region

[Guest fountainhall]

They should appoint an overseas CEO to change the culture of the remaining company.

Not only a CEO. It seems the Japanese are largely trying to manage this themselves - perhaps to save 'face', but it's a major worldwide issue. They should have assembled a team of top international experts to work on this from at least Day 2.

 

Today's New York Times has a long article in which US engineers helping with the problems are warning of a number of new threats "that could persist indefinitely".

 

United States government engineers sent to help with the crisis in Japan are warning that the troubled nuclear plant there is facing a wide array of fresh threats that could persist indefinitely, and that in some cases are expected to increase as a result of the very measures being taken to keep the plant stable, according to a confidential assessment prepared by the Nuclear Regulatory Commission.

 

Among the new threats that were cited in the assessment, dated March 26, are the mounting stresses placed on the containment structures as they fill with radioactive cooling water, making them more vulnerable to rupture in one of the aftershocks rattling the site after the earthquake and tsunami of March 11. The document also cites the possibility of explosions inside the containment structures due to the release of hydrogen and oxygen from seawater pumped into the reactors, and offers new details on how semimolten fuel rods and salt buildup are impeding the flow of fresh water meant to cool the nuclear cores . . .

 

Among other problems, the document raises new questions about whether pouring water on nuclear fuel in the absence of functioning cooling systems can be sustained indefinitely. Experts have said the Japanese need to continue to keep the fuel cool for many months until the plant can be stabilized, but there is growing awareness that the risks of pumping water on the fuel present a whole new category of challenges that the nuclear industry is only beginning to comprehend . . .

 

“I thought they were, not out of the woods, but at least at the edge of the woods,” said Lochbaum (David A. Lochbaum, a nuclear engineer who worked on the kinds of General Electric reactors used in Japan and now directs the nuclear safety project at the Union of Concerned Scientists), who was not involved in preparing the document.

 

“This paints a very different picture, and suggests that things are a lot worse. They could still have more damage in a big way if some of these things don’t work out for them . . . Even the best juggler in the world can get too many balls up in the air,” Mr. Lochbaum said of the multiplicity of problems at the plant. “They’ve got a lot of nasty things to negotiate in the future, and one missed step could make the situation much, much worse.”

http://www.nytimes.com/2011/04/06/world/asia/06nuclear.html?_r=1&ref=global-home

[Guest fountainhall]

If you are to be visiting Central Japan in the summer, be prepared for power cuts. Another Japanese nuclear plant sitting close to a major fault line is to be closed for about 3 years whilst a new tsunami-resistant wall is built. The Hamaoka plant is almost midway between Yokohama and Nagoya - or about 200 kms west of Tokyo. Seismologists estimate it has an 87% chance of an earthquake of magnitude 8.0 or higher in the next 30 years. The reduction in power generation will affect many industries near Hamaoka which presently services the 18 plants that make Toyota vehicles in Japan and all four of Suzuki Motor Corp's domestic car and motorcycle factories.

 

The coverage area also includes auto plants of Honda Motor Co and Mitsubishi Motors Corp, as well as Sharp Corp's Kameyama LCD factory and Toshiba Corp's Yokkaichi semiconductor plant.

 

http://www.swissinfo.ch/eng/news/international/Japan_to_shut_nuclear_plant_on_quake_fears%20_another.html?cid=30184246

 

Japan's prime minister, Naoto Kan, has bowed to pressure from the public and key scientific advisers and asked Chubu Electric to immediately shut down Hamaoka's two working reactors. A third reactor has been shut down for inspection and two others are being decommissioned.

 

The plant is expected to remain closed while a tsunami-resistant wall is built and emergency backup generators installed to improve its ability to function after a natural disaster.

http://www.guardian.co.uk/world/2011/may/09/hamaoka-nuclear-plant-japan-shutdown

 

Building a new 12-metre-high tsunami wall stretching nearly a mile along the Pacific coast is estimated to take 2 to 3 years. At present the power plant is protected by sand hills high enough to withstand an 8m tsunami. The waves that knocked out the plant at Fukushima were at least 14m high.

 

Which really makes me wonder why the plant operators and the government have decided that 12m is sufficient? Surely the public will insist that it's far more sensible to build higher to allow for a worst case scenario?

[Guest]

Wasn't the problem with Fukushima the loss of back up power?

So why not just move the back up power station to the nearest point that's at least 25 M above sea level? And design the supply cables to be both robust and easily repairable?

[Guest fountainhall]

Wasn't the problem with Fukushima the loss of back up power?

So why not just move the back up power station to the nearest point that's at least 25 M above sea level? And design the supply cables to be both robust and easily repairable?

It was certainly one of the key problems. I don't know the geography around Hamaoka but I suspect it may be pretty flat given the presence of so many industrial facilities in the area. That, though, would not precent them from building a tsunami-proof 25m structure.

[KhorTose]

Building a new 12-metre-high tsunami wall stretching nearly a mile along the Pacific coast is estimated to take 2 to 3 years. At present the power plant is protected by sand hills high enough to withstand an 8m tsunami. The waves that knocked out the plant at Fukushima were at least 14m high.

 

Which really makes me wonder why the plant operators and the government have decided that 12m is sufficient? Surely the public will insist that it's far more sensible to build higher to allow for a worst case scenario?

 

Actually the wave front reported by Nova and National Geo was only ten meters high at its highest points. Fukushima only had a five meter high wall, but Ryoishi did have a ten meter high wall and the wave easily topped it. Why? It appears the earth along the coast had sunk by one to two meters. That is one hell of a earthquake.

[Guest fountainhall]

Actually the wave front reported by Nova and National Geo was only ten meters high at its highest points.

I suspect wave height depends to a large extent on the height of the land just offshore - the more shallow, the higher the wave. Both The Guardian article I quote above and Time reported 14m and 48ft respectively. Time even has a video, but it's not easy to see the wave. From what I read, Nat Geo estimated the wave height at Sendai. Whatever the actual height at Fukushima, the force of the incoming water was enough to destroy several supposedly tsunami-resitant walls along the coast. I even read of some poor people standing atop their tsunami wall to watch the incoming wave.

 

http://newsfeed.time.com/2011/04/09/unavoidable-disaster-watch-the-tsunami-wave-crash-into-the-fukushima-power-plant/

[Guest fountainhall]

The firm at the centre of Japan’s nuclear disaster at Fukushima has announced that it will be able to bring the reactors under control by January 2012! This is despite evidence that the complex is more seriously damaged than at first thought.

 

According to an article today in The Guardian, TEPCO’s “roadmap” to bring everything under control has looked “increasingly unworkable” after it revealed recently that the uranium fuel rods in three of the reactors had been left exposed in the wake of the tsunami and had melted. TEPCO admitted Fuel in the No. 1 reactor has partially melted and fallen to the bottom of the pressurized vessel which holds the reactor core together. Now it appears Reactors 2 and 3 may have suffered “similar problems”.

 

And as was almost to be expected, given the company’s evasion of the truth in the early days, there are more damaging revelations.

 

The Fukushima Daiichi complex now contains thousands of tonnes of water – enough to fill 36 Olympic-sized swimming pools – adding to fears that the liquid could find its way into groundwater and the Pacific ocean if efforts fail to store it safely.

 

Questions have been raised about Tepco's original explanation for the crisis. For weeks it claimed power to vital cooling systems inside the reactors was knocked out by the 15 metre tsunami that followed the earthquake.

 

But recently retrieved data from the plant showed the earthquake had been more powerful than three of the six reactors were built to withstand, raising the possibility that at least one of the reactors was disabled before the waves arrived.

 

"This was clearly a larger earthquake than we had forecast," Junichi Matsuoto (a general manager at Tepco) said. "It would have been hard to anticipate this."

 

In another revelation that reflects badly on the firm's ability to manage the crisis, reports suggest a Tepco worker manually cut the power to the cooling system in the No 1 reactor, after data showed it was cooling too quickly in the immediate aftermath of the quake.

 

"At the time we could not have known that the tsunami was coming and that we would lose power," Matsumoto said.

http://www.guardian.co.uk/world/2011/may/17/fukushima-reactors-stable-january-operator-says

 

How anyone can have any confidence in anything TEPCO says, totally beats me!