Obituary: Masao Yoshida, nuclear engineer

Masao Yoshida. Picture: AP
Masao Yoshida. Picture: AP
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Born: 17 February, 2013, in Osaka, Japan. Died: 9 July, 2013, aged 58

Masao Yoshida was the nuclear engineer who took charge of the Fukushima Daiichi power plant two years ago as multiple reactors spiralled out of control after a tsunami, but who ultimately failed to prevent the world’s worst nuclear disaster since Chernobyl. He died from cancer yesterday at the age of 58. Yoshida had been chief manager at Fukushima Daiichi for just nine months when a 42-foot tsunami inundated the site on 11 March, 2011, knocking out vital cooling systems to the plant’s six reactors. Three reactors eventually suffered hydrogen explosions and fuel meltdowns, releasing vast amounts of radioactive matter into the environment. Although the company was criticised for its handling of the disaster, Yoshida won praise for his effort to minimise the damage.

He was faulted, however, for failing to invest in adequate tsunami walls at the company’s nuclear power plants when he was head of nuclear facilities. Yoshida later apologised, saying he had been “too lax” in his assumptions of how big a tsunami might hit the coastal plant.

Yoshida took a leave from work in late 2011 after receiving a diagnosis of esophageal cancer. Experts have said his illness was not a result of radiation exposure from the accident, given how quickly it came on.

Survivors include his wife, Yoko, and three sons.

When the tsunami hit, Yoshida took command from inside a fortified bunker at the plant. In video footage of the command room released by Tokyo Electric last year, he can be seen at times pushing his workers to hook up water hoses or procure fuel, at times tearfully apologising to teams he sent out to check on the stricken reactors.

At one point, he ignores orders from Prime Minister Naoto Kan to stop injecting seawater into one of the reactors, a last-ditch measure taken by plant workers to try to cool it.

He later offers to lead a “suicide mission” with other older officials to try pumping water into another reactor, but is dissuaded. And as officials warn that core meltdowns have most likely started, he directs men to leave the reactors but stays put in the bunker. Yoshida later said that the thought of abandoning the plant never occurred to him.

“I fear we are in acute danger,” Yoshida is heard saying in the video shortly after yet another blast rocks the command room. “But let’s calm down a little. Let’s all take a deep breath. Inhale, exhale.”

After studying nuclear engineering Yoshida worked his way up through Tokyo Electric’s nuclear power division, overseeing its nuclear facilities from 2007 until being appointed chief of Fukushima Daiichi in June 2010.

On his last day at Fukushima Daiichi in December 2011, according to a book on Yoshida by Kadota Ryusho, he again rallied his troops.

“You still have a difficult road ahead, but I know you will overcome,” Yoshida is quoted as saying. “I promise to do my best to return.”