The investigation is not over

February 9, 2013

Editorial: Fukushima nuclear disaster investigation must continue

http://mainichi.jp/english/english/perspectives/news/20130209p2a00m0na003000c.html

Looking at the Fukushima nuclear disaster, many have wondered if some vital equipment at the power plant was knocked out by the March 2011 quake and not by the ensuing tsunami as plant operator Tokyo Electric Power Co. (TEPCO) claims. Finding out is a lot harder than it should be, as TEPCO has sabotaged the disaster investigation meant to answer these types of questions.

In February last year, when the Diet's nuclear disaster investigative committee decided to carry out an on-site survey of the Fukushima No. 1 plant and asked TEPCO, the power company refused. TEPCO claimed that the No. 1 reactor building interior was "pitch black," making inspections impossible, and also said it was concerned investigators would wander into high-radiation zones. The truth was that light was shining into the shattered reactor buildings. Even a year after the event, this revelation is shocking.

Now TEPCO is saying the falsehood "was not intentional." That's hard to believe. Even if this was a crime of omission, if TEPCO simply failed to adequately check conditions at the plant for the Diet investigators, that in itself would be a major problem.

In a disaster as major as the Fukushima nuclear meltdowns, finding the cause must be given highest priority. The Diet investigation was working on behalf of the Japanese people, and thus TEPCO was duty-bound to cooperate with it to the greatest possible extent, for the sake of digging up as much truth about the disaster as there is to find.

If TEPCO gets an inspection request like the one from the Diet committee, it must assess conditions on-site and make sure the investigators can do their job without risking their health. If TEPCO had performed these common-sense tasks, there is no way the utility could have claimed the No. 1 reactor building was "pitch black" inside, because it wasn't. At the very least, TEPCO displayed a shocking lack of respect and sincerity to the Japanese people.

What the government inspectors wanted to see was the emergency isolation condenser, or IC, on the fourth floor of the No. 1 reactor building. They wanted to check if the unit had been damaged during the March 11, 2011 earthquake, before tsunami inundated the plant. The IC is supposed to pump water into the reactor core and keep it cool if the plant loses power, but it did not function properly on that day.

TEPCO insists that the IC unit was not damaged by the magnitude-9 Great East Japan Earthquake. According to one Diet investigative committee member, however, one witness stated that a water leak had been detected on the fourth floor before the tsunami hit, suggesting at least the possibility that the piping in the IC unit had been damaged in the quake.

But this issue is not just about unraveling the Fukushima disaster. Whether the quake damaged vital equipment at the plant also affects future reactor risk evaluations and safety standards. New safety standards are at this very time under evaluation at the Nuclear Regulation Authority (NRA). If reactor systems were in fact seriously damaged by the quake, that would be ample basis for demanding very strict regulations on vibration resistance.

Furthermore, after being stymied by TEPCO on its first attempt, the Diet must renew inspections, and not just of the No. 1 reactor's IC unit. The investigation into the cause of the meltdowns is not over. The Diet nuclear disaster investigative committee and its government cousin have been dissolved, their final reports filed, but the investigation must continue.

Last month, the House of Representatives established a permanent expert investigative commission on the nuclear power issue. We call on this organization to take up the mantle laid down by the previous disaster investigations and continue their work, to find out once and for all what caused the Fukushima nuclear disaster. The NRA, now building Japan's new nuclear safety standards, needs this information.

Lastly, leaving the cause of the disaster so indistinct would not just be a loss to Japan, but to the world at large. We cannot allow this to happen.