26 Février 2016
February 26, 2016
Tokyo Electric Power Co., the operator of the stricken Fukushima No. 1 nuclear power plant, said Feb. 24 that it could have declared the reactor meltdowns at the plant much earlier than it did.
The utility said it discovered a guideline in its operational manual that would have allowed it to announce core meltdowns only three days after the plant was struck by the tsunami in 2011 instead of the two months it actually took.
In a Feb. 24 news conference, a TEPCO official said the manual had been discovered for the first time earlier in February.
But the company’s explanations about the delay in announcing the meltdowns, triggered by the Great East Japan Earthquake and tsunami on March 11, 2011, and the recent “discovery” of the document are by no means convincing.
TEPCO initially maintained that the reactors suffered “core damage,” a condition in which nuclear fuel inside a reactor core is damaged, rather than a “meltdown.” It did not admit that meltdowns had occurred in the three reactors until late May 2011, more than two months later.
The utility claimed it had taken so long to acknowledge the meltdowns because there was “no basis” for making the judgment.
But this claim has proved false. At that time, TEPCO was suspected of concealing facts to make the accident look less serious than it actually was. The latest revelations revive such suspicions.
In a statement on Feb. 24, Niigata Governor Hirohiko Izumida called on TEPCO to conduct a thorough internal investigation to uncover the “truth behind its concealment of meltdowns,” including determining who gave the instructions.
Niigata Prefecture is home to TEPCO’s Kashiwazaki-Kariwa nuclear power plant, which the company aims to restart. Izumida has every right to make the demand.
Even more baffling is the “discovery” of the manual nearly five years after the nuclear crisis broke out.
Back then, core meltdowns were clearly defined as nuclear emergencies under the nuclear disaster special measures law. Given that TEPCO has been very sensitive to the question of whether trouble at a nuclear power plant, no matter how minor, should be reported to the government, it is hard to believe that the company failed to remember the standard concerning meltdowns.
It is clearly impossible to directly confirm whether a core meltdown is taking place during a severe nuclear accident.
That’s apparently the reason why TEPCO established a clear criterion for a nuclear meltdown that required the company to declare a meltdown when damage to a reactor core exceeds 5 percent.
When a nuclear accident occurs, only the operator of the nuclear plant has access to detailed data about what is happening. Both the government and news media depend on information provided by the plant operator for related policy decisions and news coverage.
A utility’s failure to swiftly offer accurate information about the situation could cause the government to make misguided policy decisions and the media to distribute incorrect reports about the accident.
TEPCO’s report on its investigation into the nuclear disaster, released in 2012, defended the company’s use of the term “core damage.” The report argued that the company had tried to provide accurate information about the conditions of the reactors based on available data by avoiding the term “core meltdown” because there was no clear and widely shared definition of the term.
It cannot be said that TEPCO provided the entire picture of what happened based on exhaustive and effective efforts to identify all the factors involved.
The company’s guideline concerning core meltdowns was “discovered” during an in-house investigation into how the utility responded to the Fukushima nuclear crisis. That investigation was conducted at the request of a technical committee of the Niigata prefectural government.
The prefecture called for a fresh inquiry in connection with TEPCO’s plan to restart the Kashiwazaki-Kariwa nuclear power plant.
TEPCO has said it will look into how it failed to notice the existence of the guideline through a probe involving outsiders.
The utility should determine who should be held accountable for that failure.
The company also needs to offer convincing answers to such questions as how it will prevent a recurrence and whether problems with its corporate culture played a role. Otherwise, its efforts to regain public trust are destined to fail.
--The Asahi Shimbun, Feb. 26