Fukushima Daiichi’s reactor No 1 was granted 10-year operational extension despite warnings of its frailties: 120,000 imperilled by radiation poisoning

Publish date: March 22, 2011

Written by: Charles Digges

Just weeks prior to the 9.0 earthquake and tsunami that crippled the Fukushima Daiichi plant and cooling back up systems at its reactors, Japanese officials had granted a 10-year operational extension to the 40-year-old reactor No 1 despite several warnings, the New York Times reported.

The issue has implications for Russia, where cozy relations between the nuclear industry and safety inspectors led to engineering life time extensions at old reactors that should be decommission on a regular basis. Recent decade long extensions have been granted to reactors at Russia’s Leningrad, Kola and Kursk nuclear power plants.

No less tight relations between the government and inspectors in Japan seem to have contributed to the untimely clean bill of health for Fukushima Daiichi’s reactor No 1 reactor.

The Russian environmental group Ecodfence was Wednesday calling for a protest in front of the offices of Rosatom, Russia’s state nuclear corporation, In Moscow over the company’s obdurate refusal to heed the lessons of Fukushima Daiichi by reviewing its safety policies. Ecodefence warns that some 120,000 people in Japan are now at risk for radiation poisoning, citing a modelling structure developed by the European Committe on Radiation Risk.

All remaining five of the reactors at Fukushima Daiichi, including 13 more reactors throughout Japan, have been due for such extension reviews over the next 10 years.

The extra 10-year lease on life granted by Japanese regulators, said Bellona physicist Nils Bøhmer, “shows that a strong, independent nuclear safety regulatory agency needs to be in place that is not beholden to the government’s desires.”

Tokyo Electric Power Co (TEPCO), which runs the Fukushima Daiichi, has since the extension been in a lethal struggle to keep reactor No 1 and its spent fuel pool from overheating and emitting radioactive materials, dousing it with water from fire trucks and riot control water cannons and endeavoring to hook an electrical cable to it.

Specifically, regulators who reviewed the plant pointed out they had found 33 stress cracks in the diesel generators that provide back up power to the cooling system should disaster befall power to the main cooling system, according to a summary of the regulation committee’s deliberations that was posted on the website of Japan’s nuclear regulatory agency.

The cracks in the generator system left then vulnerable to corrosion from seawater and rainwater at the seaside plant 240 kilometres north of Tokyo, regulators said in the report, as cited by the New York Times.

These back-up generators failed on the day of the quake, and were unable to compensate for the loss of the primary cooling power source, which has led to the most critical nuclear power station emergency since Chernobyl, say experts.

Regulators said in their report that “maintenance management was inadequate” and that the “quality of inspection was insufficient.”

Nonetheless, after only three visits to the plant to determine its integrity for continued operations, the regulation committee pronounced that the reactor would be able to withstand earthquakes.

It did, however issue caveats that the operator TEPCO to monitor potential damage from radiation to the reactor’s pressure vessel, which holds fuel rods; corrosion of the spray heads used to douse the suppression chamber; corrosion of key bolts at the reactor; and conduction problems in a gauge that measures the flow of water into the reactor, according to a report published in early February, the paper said.  to

The Japanese public is opposed to plans for further builds of nuclear power plants. The country has a sensitive relationship to nuclear power, having been the only country in history to be bombed by atomic weapons, and perception among Japanese citizens is rife with suspicion that officials operate without fully disclosing possible dangers at the country’s 55 nuclear power plants.

The events that have unfolded since March 11 have only underscored Japan’s suspicion of officials. Indeed, granting extensions to existing, and possibly dangerous, nuclear power units, is a practice that is popular as it circumvents public relations fallout with the public that comes with new reactor builds.

“This practice is quiet and cheap – if everything goes right,” said Bøhmer, which in this case it did not.

“The must assure safety at all costs via assurances from an independent oversight agency,” said Bøhmer. “What has been revealed show that this body in Japan is not independent enough.”

The No 1 reactor at Fukushima Daiichi was built by the US General Electric corporation and went into service in 1971. Experts, even those involved in its design, say the model is out of date. Reactor Nos 2, 3 and 4 at the plant are somewhat younger, though that has not prevented extreme crises at these units as well.

Mitsuhiko Tanaka, an engineer who worked on the design of the reactors at the Fukushima Daiichi plant, told the New York Times that the the reactors there were outmoded.

Particularly risky, he told the paper, is their small suppression chambers, which increased the risk that pressure would build up within the reactor – which it did – and is a a fault that has been eliminated in newer reactors.

Since the quake, officials at Fukushima Daiichi have tried to relieve rising pressure inside the reactors, several times resorting to releasing radioactive steam into the atmosphere, a measure that in turn has contributed to the growing contamination of food and water in the area.

“It was about time the reactor was replaced,” Tanaka told the newspaper. “The tsunami would have caused great damage, regardless. But the pipes, the machinery, the computers, the entire reactors — they are just old, and that did not help.”