Nearly 4,000 spent fuel assemblies were stored at the Fukushima Daiichi unit — more than thrice the amount of fuel in the six cores

Japan's Prime Minister Naoto Kan had every reason to ask the executives of the Tokyo Electric Power Company (TEPCO), “What the hell is going on?” His outburst was in response to the delay of nearly an hour by TEPCO officials to alert him about the third explosion at the Fukushima nuclear facility.

Can it be dismissed as a slip on the part of TEPCO officials, given the emergency situation at the nuclear facility? Quite unlikely.

This is not an isolated case, and TEPCO has a dubious track record of falsification and concealing crucial data, including safety data, of the nuclear plants.

Ticking time bomb

It has now come to light that the company has been storing 4,000 spent uranium fuel assemblies at its nuclear units at Fukushima Daiichi.

This is equivalent to almost the amount of highly radioactive uranium fuel produced in six years by the units and more than three times the amount of radioactive material present in the cores of all the six units.

For instance, Unit-4 had some 548 still-hot fuel assemblies stored in a pool of water in the upper floor. It was the lack of cooling water in this pool that ultimately led to an explosion of the roof of Unit-4.

More than 60 per cent of the spent fuel from the facility is stored in a separate pool built in 1997.

According to Reuters, constrained by space, TEPCO had initiated steps to increase the storage capacity of spent fuel inside the reactor buildings by “re-racking” the pools. There were other plans for increasing the storage capacity outside the reactor buildings.

But only the reactor buildings offered sufficient open space for any significant increase in storage capacity. “TEPCO had the capacity to more than double the number of fuel assemblies stored in the reactors from 3,998 at the time of the quake to 8,310 assemblies,” according to Reuters.

No safety checks

The Guardian reports that TEPCO had missed safety checks over a 10-year period up to two weeks before the March 11 quake. For instance, the company had failed to carry out safety checks on 33 pieces of equipment inside the plant's cooling system. The company's admission of this omission came weeks after government regulators approved prolonging of the life of one of the six reactors.

This is not the fist time that TEPCO had violated safety norms, concealed crucial safety data, or even vital information about geological fault structures.

Turning a blind eye

It was after the 2007 earthquake of 6.8 magnitude, which hit the seven reactors at the Kashiwazaki-Kariwa plant in Japan's west coast that it became clear that the reactor facility was built directly on top of a seismically active fault line.

People were told about this only after the quake.

According to Nature, scientists knew about the presence of an active fault under the nuclear facility but it was “ignored when the plant was enlarged.”

TEPCO had apparently found a seven-km long fault line during the course of its investigation prior to expanding the facility. “But [TEPCO] failed to investigate it fully,” notes Nature.

Hiroaki Nakata, a seismologist at the Hiroshima Institute of Tehnology was quoted as saying in Nature: “There's no reason for TEPCO to have stopped when they [found the fault line]. There are many places where they missed — or intentionally avoided — seeing fault lines.”

The damage to the plant was minor and no one died and the amount of radiation released was reportedly negligible. Yet, this and many other instances dented the public's faith and trust.

According to Nature, it became clear that 1,200 litres of contaminated water released from the Kashiwazaki-Kariwa facility into the ocean was 50 per cent more radioactive than what TEPCO had previously stated.

Other instances

There have been many instances when TEPCO had behaved irresponsibly. In February 2007, the company admitted to 199 cases of falsifying inspection data at three nuclear power plants, including Kashiwazaki-Kariwa. TEPCO was found to be slow in reporting two radiation leaks and miscalculating the amount of radiation released.

In 2002, a major scandal hit the company. A government investigation revealed that TEPCO had systematically concealed safety breaches for a period stretching to nearly two decades.

A three-year investigation revealed that up to 13 of the protective shells surrounding reactors had cracks. And the company officials knew about this.

TEPCO ordered closure of all its reactors after it admitted to falsifying data in about 30 safety logs and up to 200 incidents. This included the now infamous Fukushima Daiichi Unit-1.

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