Monday, March 14, 2011

Fukushima accident triggers reappraisal of nuclear power

The unprecedented Fukushima nuclear power accident is the worst since Chernobyl and is causing a significant reappraisal of plans to develop nuclear power everywhere in the world.

The latest news is that a third reactor has lost its cooling system. A second explosion has injured 11 people, one of them seriously.

The authorities have so far categorised it as a level 4 event on the International Nuclear and Radiological Event Scale - an accident with local consequences, where there is a minor release of radioactive material, unlikely to result in implementation of planned countermeasures other than local food controls.

Radiation levels and secrecy

However, independent journalists from the Japan Visual Journalist Association (JVJA) and Ryuichi Hirokawa, editor-in-chief of DAYS JAPAN (magazine), went on Sunday to Futaba Town where the Fukushima Daiichi reactors are located to undertake independent monitoring.

Hirokawa said measurements taken near the high school at Futaba were higher than when he had taken measurements approximately 200 meters from unit 4 at Chernobyl shortly after that explosion.

He added, "At the front of the Futaba Town Hall, all our three radiation monitors went off scale and became inoperable (we could not take measurements). At the entrance of the hospital, stretchers were turned over, many things were scattered, a feeling that evacuation had been undertaken in a very rushed way."

Yet, a statement today by the International Atomic Energy Agency said "Radiation dose rate measurements observed at four locations around the plant's perimeter over a 16-hour period on 13 March were all normal."

These discrepancies in reports do not inspire confidence. Secrecy is a major issue in public confidence about nuclear power. In 2002 a scandal about widespread falsification of safety documentation lead to the shutting down of all of Tokyo Electric Power Company’s 17 nuclear reactors.

It will probably be some time before we find out exactly what has transpired, and there may be more explosions. However, the fact that there is now a 12 mile exclusion zone around the site gives some idea of its seriousness.

Security against earthquakes

Masashi Goto, the designer of the containment vessel at the Fukushima plant, a former employee of Toshiba, held a press conference on 13 March with the Citizens' Nuclear Information Center in which he catalogued how the industry in Japan had been warned about the vulnerability of its reactors to earthquakes and ignored the warnings.

He said that the intensity of the quake in 2008 which cracked the reactor cooling towers at the Kurihara Nuclear Power Plant, spilling wastewater and damaging the reactor core, exceeded the design capability of the vessel to withstand it by almost three times, and that the only reason why a major disaster did not happen on that occasion was pure coincidence.

Reuters reports that even faithful workers have had their trust shaken. "The company has been saying such a thing would not happen and the plant was fine even after 40 years in operation...It only raised my distrust of TEPCO." said Mikiko Amano, a 55-year-old woman who had been recently evacuated from her home close to the quake-stricken Fukushima Daiichi nuclear complex.

Four plants have been shut down since the first Fukushima explosion, closing 20% of Japan’s nuclear capacity. 34% Japan's history comes from nuclear power. Even Tokyo Electric Power has called it "a considerably serious situation."

Doubts over the reactor type

The Fukushima plant is a General Electric Mark I reactor. There are 23 of this type in the U.S. It is a Boiling Water Reactor (BWR) of which there are 192 in the world, some still under construction.

The design has been criticised by nuclear experts and even Nuclear Regulatory Commission staff for decades as being susceptible to explosion and containment failure.

As early as 1972, Dr. Stephen Hanuaer, an Atomic Energy Commission safety official, recommended that the pressure suppression system be discontinued and any further designs not be accepted for construction permits.

Shortly thereafter, three General Electric nuclear engineers publicly resigned their positions citing dangerous shortcomings in the GE design.

An NRC analysis of the potential failure of the Mark I under accident conditions concluded in a 1985 report that Mark I failure within the first few hours following core melt would appear rather likely.

In 1986, Harold Denton, then the NRC's top safety official, told an industry trade group that the "Mark I containment, especially being smaller with lower design pressure, in spite of the suppression pool, if you look at the WASH 1400 safety study, you'll find something like a 90% probability of that containment failing."

A statement issued by the Japanese Citizens' Nuclear Information Center expressed concern for the people living in the vicinity of Japan's nuclear power plants and called for a phasing out nuclear energy.

"Last December the Japanese government began a review of its nuclear energy policy," said Philip White its international liaison officer. "The review was commenced in the spirit of essentially confirming the existing policy. That approach is no longer viable. The direction of the policy review must be completely reversed."

The industry is countering that at least a major explosion of the containment vessel itself has been avoided. This is not 3 mile Island or Chernobyl, they say.

However, the accident is without precedent, and so were these others. The industry can only prepare within its economic constraints for probable accidents, and it is the improbable ones which are the most catastrophic.

Countries around the world are now commencing an evaluation of nuclear safety - India being one of the first to announce this move.

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