The transcripts of the interviews of 19 people who dealt with the March 2011 triple meltdowns at Tokyo Electric Power Co.’s Fukushima No. 1 nuclear power plant, including the late Masao Yoshida, then chief of the plant, may offer little new information about the worst nuclear disaster since Chernobyl but still provide important lessons that must be learned for management of future crises.
Last week’s release of the transcripts had been closely watched, especially due to conflicting reports by some members of the media over the interview of Yoshida, who led the desperate efforts to contain the situation at the crippled plant after the 3/11 tsunami destroyed the emergency generators needed to operate the reactors’ cooling system, and an apology by the Asahi Shimbun after the release stating that its earlier report — which alleged that many of the workers at the No. 1 plant had defied Yoshida’s orders and fled to the Fukushima No. 2 plant at the height of the crisis — was erroneous.
However, the naming of names should not let us lose sight of what the transcripts tell us about what transpired among people at the plant, the Tepco headquarters in Tokyo and the government as they tried to deal with the crisis — which will be all the more important as the power industry and the Abe administration move to restart nuclear power plants idled in the wake of the 2011 disaster.
The 19 people, including then Prime Minister Naoto Kan and key members of his Cabinet, were among a total of 772 people interviewed for the government’s probe into the Tepco plant disaster. Yoshida, who died of esophageal cancer last year, reportedly asked that the transcript not be made public saying that his statements may include erroneous recognition of facts, but the government decided to release his and others’ transcripts after media reports gave conflicting accounts of Yoshida’s testimony.
In the roughly 400 page transcript, Yoshida gives vivid descriptions in candid words of what he thought and did as he and his men faced the loss of power at the plant. His testimony shows that Tepco had not been prepared for the cutoff of emergency power. Yoshida admits that he did not have an answer ready on how to cool the reactors in such a situation. He repeatedly talks of “death” in the initial days of the crisis as the realization sinks in that the nuclear fuel had already started to melt, and might melt through the reactors’ container vessels and release massive amount of radioactive substances.
Yoshida flatly denies that he thought of withdrawing all his men from the plant even as fears rose of the worst-case catastrophe — which Kan and his Cabinet suspected as they heard reports from the power company’s top executives. He says he pondered keeping a skeleton crew at hand to manage the crippled reactors but having all other nonessential workers to evacuate. The transcript shows that many workers in fact braved the danger and worked desperately to keep the situation under control.
Still, even the men who Yoshida counted among the nation’s most capable engineers with trouble-shooting experience were unable to prevent the core meltdowns, which left large areas around the Fukushima No. 1 plant uninhabitable due to the radiation fallout more than three years after the disaster — and likely even much longer.
The safety standards updated in the wake of the Fukushima crisis call for measures to make nuclear power plants resilient against natural disasters, including maximum possible quakes and tsunami forecast on their sites, as well as steps to deal with severe accidents. It still needs to be verified if a system has been established in which workers at each plant will be able to manage situations that have not been foreseen — as happened at the Fukushima plant — in future possible crises. Upgrading plant hardware alone would not be sufficient to manage crises, in which, as Yoshida’s accounts show, things may not work out as they are presupposed to.
In his testimony, Yoshida defends Tepco’s inaction in response to a 2008 simulation by experts that the No. 1 plant could be hit by a tsunami as high as 15.7 meters if a strong quake hits off Fukushima Prefecture. As head of Tepco’s department responsible for managing its nuclear power plant equipment to prepare for natural disasters when he was informed of the scenario, Yoshida says that the power company needed to assess the cost-efficiency of measures to invest money in measures to deal with the hypothetical simulation — which turned out to have rightly gauged the estimated 15.5 meter height of the tsunami that hit on March 11, 2011. It needs to be closely monitored if the power companies still follow the same business logic as they respond to the updated plant safety standards.
The July 2012 report by the government’s investigation into the Fukushima nuclear disaster pointed to a shortage of information about events at the plant reaching the prime minister’s office. Kan’s administration came under criticism that its “meddling” — apparently based on insufficient information — created confusion in the on-site team’s fight to contain the situation at the plant. The released transcripts underline the communication failures between the government and Tepco headquarters — and between Tepco’s top executives in Tokyo and the Fukushima plant team.
A typical episode is the order by a senior executive at Tepco headquarters to Yoshida on March 12, 2011, to stop the injection of seawater to cool Reactor 1 after the supply of fresh water ran out. The executive, who had reportedly been urged by Kan to look into the possibility of seawater injection causing a nuclear chain reaction known as recriticality, told Yoshida that seawater injection had not yet been approved by the prime minister’s office. Yoshida’s decision to ignore the executive’s order and keep on injecting seawater is credited for preventing the situation from worsening. Kan, in his interview transcript, says he never told Tepco to halt the seawater injection and blames miscommunication and misunderstanding on Tepco’s part.
In the part of the transcript where Yoshida recounts the repeated urging from the Tepco headquarters and the government to hasten the venting operations to release radioactive steam from the stricken reactors to reduce the buildup of pressure on the morning of March 12, he says there was a distinct gap between the on-site staff at the plant and the Tokyo headquarters in the recognition of what’s going on — which he says was even wider between the plant staff and the prime minister’s office.
It remains unclear if the government and power companies have learned from such communication gaps — perhaps other than to blame leaders of the previous DPJ-led administration. The government does not appear to have done much to follow up on its 2012 report to dig deeper into how the Fukushima disaster evolved into a crisis. It needs to use the testimonies of Yoshida and others, including those that remain confidential, to learn what went wrong before and during the events in 2011, and to help avert or contain future crises.