Talking of tsunami barriers...again

February 28, 2018

Court told ex-Tepco Execs were informed barriers could prevent tsunami flooding at Fukushima plant

https://www.japantimes.co.jp/news/2018/02/28/national/court-told-ex-tepco-execs-informed-barriers-prevent-tsunami-flooding-fukushima-plant/#.Wpa-wHwiGos

JIJI

An employee with a subsidiary of Tokyo Electric Power Company Holdings Inc. testified in court Wednesday that the unit reported a need to install tide barriers to prevent flooding from a tsunami well before the March 2011 nuclear accident at Tepco’s Fukushima No. 1 nuclear plant.

According to the worker, the Tepco unit produced an estimate in March 2008 on the basis of long-term assessments released by a government organization, saying that a tsunami could occur with a height of 15.7 meters, which is above ground level at the nuclear plant site.

The estimate was presented at a meeting in June the same year that was attended by Sakae Muto, a former Tepco vice president.

The worker testified during a hearing at the Tokyo District Court that the Tepco unit estimated the tsunami height to reflect the latest information on a possible massive earthquake off Fukushima Prefecture, home to the now-devastated nuclear plant.

After finding that the nuclear plant site was vulnerable to flooding, the subsidiary reported at the meeting that installing 10-meter tide barriers would provide protection from a tsunami, the worker said.

The worker gave the testimony as a witness in the trial of three former Tepco executives, including Muto, 67, who were indicted in February 2016 for allegedly neglecting to take measures against massive tsunami. A prosecution inquest panel comprising ordinary citizens has overruled decisions by public prosecutors twice not to charge the executives. In the indictment, they were charged with professional negligence resulting in death and injury over the accident.

Lawyers appointed by the district court to act as prosecutors have said that former Tepco Chairman Tsunehisa Katsumata, 77, and former Vice President Ichiro Takekuro, 67, were also informed of the tsunami estimates on separate occasions. The lawyers claimed that the three former Tepco executives could have foreseen that a massive tsunami might hit the nuclear power plant.

The former executives denied the claim during the first hearing in their trial in June 2017, saying that the company would have been unable to prevent the accident even if measures were taken based on the estimate.

February 28, 2018

TEPCO asked for 'smaller tsunami' in simulation

https://www3.nhk.or.jp/nhkworld/en/news/20180228_33/

An employee at a group company of the operator of the damaged Fukushima nuclear power plant says he was asked to decrease his estimate of a projected tsunami. This was 3 years before the 2011 disaster that caused the severe nuclear accident.

He testified as a witness on Wednesday before the Tokyo District Court in the trial of 3 former executives of Tokyo Electric Power Company, or TEPCO. The defendants are accused of professional negligence resulting in deaths in connection with the nuclear accident.

In 2008, the witness was in charge of estimating the height of a tsunami assumed to hit the plant.

In his testimony, he said he estimated that tsunami as high as 15.7 meters could hit the plant in a report submitted to TEPCO.

However, he said, a TEPCO official in charge asked him to lessen the height of tsunami by altering calculation conditions and the movement of tsunami.

The witness testified that he answered that he could not alter the calculation conditions as they are used by experts at conferences.

He made the statement while answering a question by a designated lawyer who is serving as a prosecutor.

The presiding judge asked him to be more specific about his conversation with TEPCO, but he replied that he had no memory of it.