(Updates with reprimand in 13th paragraph.)
Nov. 30 (Bloomberg) -- Masao Yoshida, who led the fight to bring Japan’s crippled Fukushima nuclear station under control, steps down tomorrow for medical treatment after almost nine months directing the disaster response from inside the plant.
Yoshida, 56, was hospitalized on Nov. 24. His employer, Tokyo Electric Power Co., didn’t specify the ailment in a statement on Nov. 28, citing privacy reasons. The company declined to say where Yoshida is being treated.
The nuclear engineer was manager of the Fukushima Dai-Ichi station on March 11 when Japan’s strongest earthquake on record and an ensuing tsunami hit the plant, causing the worst nuclear disaster since Chernobyl 25 years ago.
“Yoshida certainly won the respect of his men,” said Shigeharu Aoyama, who met him on April 22 at Fukushima Dai-Ichi after gaining access as a special member of Japan Atomic Energy Commission. “His decisions and courage saved lives.”
Radiation exposure is unlikely to be the cause of Yoshida’s illness, Tetsuo Ito, the head of Kinki University’s Atomic Energy Research Institute, said in a phone interview. Heavy radiation exposure would bring a quick onset of acute diseases, while late-onset diseases from radiation, such as cancers, take several years to develop, Ito said.
“Yoshida has been under tremendous stress given he’s taken the lead since the accident,” Ito said.
Yoshida informed Tepco President Toshio Nishizawa on Nov. 21 that he needs treatment after undergoing medical checks earlier this month, Junichi Matsumoto, a general manager at the company, said on Nov. 28.
After studying nuclear engineering at the Tokyo Institute of Technology, Yoshida joined Tepco in 1979, according to the utility. He was appointed head of the Fukushima Dai-Ichi plant in June 2010.
As radiation levels spiked in the early days of the crisis, workers were pulled out of the plant leaving behind what became known as the Fukushima Fifty who risked their lives to bring the reactors under control.
Spain awarded the Fukushima Fifty the Prince of Asturias Concord prize in September, calling them the “heroes of Fukushima.”
“Yoshida has made a huge contribution and I want him to focus on curing his illness,” Goshi Hosono, minister in charge of the response to the nuclear disaster, told reporters in Tokyo yesterday. “Yoshida’s leadership deserves rich praise and he has my sincere respect.”
On March 12, a day after the tsunami, Yoshida ignored an order from Tepco headquarters to stop pumping seawater into a reactor to try and cool it.
Tepco said it may penalize Yoshida even though Sakae Muto, then a vice president at the utility, said it was a technically appropriate decision. Yoshida received a verbal reprimand after then Prime Minister Naoto Kan defended the plant chief, the Yomiuri newspaper reported.
“If Yoshida stopped pumping seawater, workers could have died,” said Aoyama. “They won’t forget that.”
“It’s our mission to ensure stable operations of the plant with safety as the top priority,” Yoshida said in a New Year greeting about two months before the nuclear disaster.
Yoshida thought several times those at the plant were going to die, he told reporters who visited the Fukushima station on Nov. 12, the Mainichi newspaper said. Yoshida told reporters he thought plant operators may completely lose control as the meltdowns accelerated, the Mainichi said.
“Yoshida told me that he couldn’t imagine such a big tsunami would come after an earthquake,” Yotaro Hatamura, an engineering professor at the University of Tokyo who is investigating the accident, said in June. “From our discussions, I gathered that no one at the plant could imagine that such a tsunami would occur.”
Takeshi Takahashi, 54, general manager of Tepco’s nuclear power plant management department, will replace Yoshida, the utility said in a statement. Yoshida will remain as an executive officer of the nuclear power and plant siting division, it said.
“I feel as if my heart is breaking, leaving everyone I’ve worked with since the disaster this way,” Yoshida wrote in a message to workers at the plant when he left for hospital, according to a faxed statement from the utility. “I will concentrate on the treatment and do my best to be at work with you again as soon as possible.”
--With assistance from Chisaki Watanabe in Tokyo. Editors: Aaron Sheldrick, Indranil Ghosh
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