Masao Yoshida, the former chief of the Fukushima No. 1 nuclear plant who stayed at his post to try to tame the three runaway reactors after the 2011 quake and tsunami, died Tuesday of esophagus cancer. He was 58.
Yoshida was at the power station on March 11, 2011, when the towering waves swamped the cooling systems and sparked the meltdowns that released plumes of radiation.
Yoshida led the subsequent effort to get the crippled complex under control as workers battled frequent aftershocks to try to prevent the disaster from worsening.
Government contingency plans revealed after the event showed how scientists feared a chain reaction if Fukushima spiralled out of control, a scenario that could have seen other nuclear plants engulfed and would have meant evacuating Tokyo.
His selfless work is contrasted in the public mind with the attitude of his employers at Tokyo Electric Power Co., who seemed willing to abandon the complex and are popularly believed to have shirked their responsibility.
“He died of esophagus cancer at 11:32 a.m. today at a Tokyo hospital,” a Tepco spokesman announced.
Yoshida left the plant soon after being suddenly hospitalized in late November 2011.
Tepco has said his cancer was unlikely related to radiation exposure.
The company has said it would take at least five years, and normally 10, to develop this particular condition if radiation exposure were to blame.
Soon after he underwent surgery for cancer, Yoshida was felled by a brain hemorrhage and underwent another operation in July 2012, Tepco said.
He was still employed by the company at the time of his death.
The disaster saw three reactors go into meltdown, spewing radiation into the air, sea and food chain in the worst nuclear accident since the 1986 Chernobyl disaster.
No deaths have been directly attributed to the radiation released by the accident, but it has displaced tens of thousands of people and left large areas of land uninhabitable, possibly for decades.
The plant remains fragile, with Tepco struggling to deal with the tons of radioactive water left over from efforts to cool the molten reactor cores.
Tepco said Tuesday that toxic radioactive substances in groundwater have rocketed over the past three days and engineers do not know where the leak is coming from.
Samples taken Monday showed that levels of possibly cancer-causing cesium-134 were more than 90 times higher than on Friday, at 9,000 becquerels per liter, Tepco revealed.
Levels of cesium-137 stood at 18,000 becquerels per liter, 86 times higher than at the end of last week, the utility said.
Scientists say fully decommissioning the plant will take 30 to 40 years.