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Keeping transparency

May 24, 2011

TEPCO has announced that fuel rods in three of the six reactors in the Fukushima Daiichi nuclear power plant more than likely partially melted down a few weeks ago.

Tokyo Electric Power Co. (TEPCO) President Masataka Shimizu speaks during a news conference

More and more details from the first 24 hours after the disaster at the Fukushima nuclear power plant are being published; discussions in Japanese media are becoming more and more heated about who was responsible. Nuclear expert Masanori Naito told NHK, Japan’s public broadcaster, "The hydrogen explosions were the reason the situation became so bad.” Naito added,”That is why it will take such a long time before the situation becomes stable in Fukushima 1. The operator was too slow to reduce the pressure on the valves."

Each decision made at Fukushima has been documented down to the minute, like the decision to release the valve in reactor 1 to release radioactive steam. The documentation also shows that it was not easy for the workers to get into the buildings because of the high radiation levels. That is the reason they were not able to fully release the valve.

Because the cooling pumps were malfunctioning, Fukushima engineers had to turn to seawater
Because the cooling pumps were malfunctioning, Fukushima engineers had to turn to seawaterImage: AP

Naito explained, "The high radiation means that particles escaped from the reactors. Probably because a fusion had already started to happen."

Partial meltdowns partially understood

According to TEPCO, the meltdown in reactor 1 took place just one day after the earthquake and ensuing tsunami on March 11, 2011. The operator has recently publicly announced that there were also partial meltdowns in reactors 2 and 3 as well, which, according to the operator, took place 60 to 100 hours later. It is still not fully understood what caused it.

The operator expects to have the power plant back under control by January next year. TEPCO has stated that the coolant pumps were not damaged in the earthquake because they had been functional before the tsunami; that after that, the emergency mechanisms did not kick in as they should have.

Experts say the hydrogen explosions may have been avoidable
Experts say the hydrogen explosions may have been avoidableImage: AP

Nuclear expert Naito told Japanese radio, "No one, including myself, seriously thought such a disaster would occur. We would have never thought that the back-up energy sources would malfunction simultaneously. We had prepared for the worst possible scenario, but we never really believed that it would ever happen. We were naïve."

Water was stopped

Critics of Japanese PM Naoto Kan’s government have criticized the government’s "negligence." Some of his critics suspect his crisis management team of giving the order to stop cooling the reactors with sea water for a short time in order to make an assessment of the situation. Recordings have proven that the flow of water was stopped for 55 minutes on March 12 - over a day after the earthquake and tsunami.

Prime Minister Kan has defended himself in front of the Japanese parliament by saying, "There was never any order from me or from any of my colleagues to stop the flow of water. On the other hand, it must be said, that neither I nor anyone in my cabinet had been given a correct assessment of the situation at that time."

Police officers enforce the evacuation zone around the Daiichi plant
Police officers enforce the evacuation zone around the Daiichi plantImage: AP

Communication problems between the government and TEPCO became evident just hours after the disaster began. Had TEPCO followed the guidelines, the hydrogen explosion in reactor 1 may have been prevented. The guidelines state that the valves must be released immediately if pressure builds up to over twice the amount it should be. But the guidelines do not mention how workers are to get to the valves during an emergency - at a time when radiation levels are soaring.

Author: Peter Kujath (sb)
Editor: Ziphora Robina

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