A former vice president of Tokyo Electric Power Co. refused to take any responsibility for the Fukushima nuclear disaster, testifying in court Oct. 16 that he was never made aware of the possibility of destructive tsunami striking the facility and, therefore, did not authorize countermeasures.

Sakae Muto, 68, is on trial on a charge of professional negligence resulting in death and injury over the March 2011 catastrophe at the Fukushima No. 1 nuclear power plant, along with Tsunehisa Katsumata, a former TEPCO chairman, and Ichiro Takekuro, another former TEPCO vice president.

Towering tsunami generated by the Great East Japan Earthquake inundated the coastal complex, knocking out cooling systems and triggering a triple meltdown.

Muto denied in the Tokyo District Court that he and the two other top executives once gave the green light for countermeasures against a powerful tsunami three years before the disaster occurred.

“We were never notified that such a thing could happen," Muto stated.

To prove negligence, prosecutors must show that top executives could have reasonably predicted the scale of the tsunami that swamped the plant, setting off the most serious nuclear accident since the 1986 Chernobyl disaster.

Muto’s testimony followed oral statements given in a previous court hearing by Kazuhiko Yamashita, head of TEPCO’s center tasked with compiling anti-earthquake measures.

In the statetments, Yamashita said he notified Muto, Katsumata and Takekuro in a February 2008 meeting that the height of a powerful tsunami predicted to hit the site would be at least 7.7 meters.

Yamashita’s team arrived at the figure using a simplified calculation based on the long-term assessment of the probability of major earthquakes released by the government’s Headquarters for Earthquake Research Promotion in 2002.

Yamashita said in his statements that he took it that the three executives understood his team’s projection was based on a government assessment and that they approved taking anti-tsunami measures.

Yamashita's statements were made to prosecutors between 2012 and 2014, when he was under investigation in connection with the nuclear disaster. The court accepted them as evidence.

A TEPCO subsidiary’s civil engineering team came up with a figure of 15.7 meters after conducting a more detailed study.

The update was conveyed to TEPCO executives in June that year. But Muto, who was deputy chief of the company’s nuclear power and plant siting division, instructed subordinates the following month to shelve the anti-tsunami measures, according to witnesses who testified in previous hearings.

Asked about the February meeting, Muto denied that he was notified destructive tsunami could strike, or safety steps were required.

“No such topics were raised during the meeting,” he stated.

Muto also characterized the meeting that included Katsumata and Takekuro as “not one to make a decision as an organization, but one to share information.”

With regard to the projection of 15.7 meters, Muto said, “I was briefed that the (government’s) long-term assessment is not credible and thought that no new scientific expertise was available."

He also rejected suggestions that he postponed taking anti-tsunami measures.

“I simply thought it would be difficult to come up with a design for a strong sea wall straight away,” he said.

Asked whether it was possible that his division alone was empowered to halt plant operations in anticipation of encroaching danger, he emphatically denied this was so.

He said a decision of such gravity is "too weighty in terms of business management that the nuclear power and plant siting division’s decision alone cannot make it happen.”

Muto went on to state: “It would have been necessary for the division to consult with not only many divisions and sections of our company, but also other utilities and central and local governments and explain to them the grounds and the need to halt operations.”

He started his testimony by offering a “deep apology” for causing “trouble beyond description” to people affected by the nuclear disaster.

The Fukushima No. 1 nuclear plant’s reactor buildings sit on elevated land 10 meters above sea level. The tsunami spawned by the magnitude-9.0 earthquake reached 15.5 meters around the reactor buildings, according to traces left there.

Prosecutors had initially declined to press charges against the three former executives, citing insufficient evidence. However, a committee for the inquest of prosecution twice concluded that the trio should be indicted.

(This article was written by Mikiharu Sugiura and Chikako Kawahara.)