Masao Yoshida (nuclear engineer)

Masao Yoshida is a General Manager in the Nuclear Asset Management Department of the Tokyo Electric Power Co., Inc. (TEPCO), Japan. He was the plant manager during the Fukushima Daiichi nuclear disaster, where he played a critical role by disobeying corporate headquarter orders to stop using seawater to cool the reactors.^[1] According to nuclear physicist (and co-founder of String field theory), Dr. Michio Kaku, the decision to use seawater arguably prevented a much greater disaster.^[2] The massive influx of seawater is the only thing that stopped the cores from exploding, according to Dr. Kaku, who added this was a last ditch effort. Yoshida managed to gain the trust of Prime Minister Naoto Kan, who he met the day after the tsunami on a plant tour. They had both attended Tokyo Institute of Technology.

On March 12, about 28 hours after the tsunami struck, Tepco executives had ordered workers to start injecting seawater into Reactor No. 1. But 21 minutes later, they ordered Yoshida to suspend the operation. Yoshida chose to ignore the order. At 20:05 JST that night, the Japanese government again ordered seawater to be injected into Unit 1.^[3]

The week of June 7, 2011, TEPCO gave Mr. Yoshida a verbal reprimand for defying the order and not reporting it earlier.

References

1. ^ "In Nuclear Crisis, Crippling Mistrust". New York Times.. 12 June 2011. http://www.nytimes.com/2011/06/13/world/asia/13japan.html?hp=&pagewanted=print. 
2. ^ "Physicist Michio Kaku: We came close to losing northern Japan". CNN.. 1 June 2011. http://cnnpressroom.blogs.cnn.com/2011/06/01/physicist-michio-kaku-we-came-close-to-losing-northern-japan. 
3. ^ "Seismic Damage Information(the 19th Release)". Nuclear and Industrial Safety Agency. 13 March 2011. http://www.nisa.meti.go.jp/english/files/en20110313-3.pdf. Retrieved 12 April 2011. 

External links

• Mainichi article
• blog report

Persondata
Name	Yoshida, Masao
Alternative names
Short description	Plant manager during the Fukushima Daiichi nuclear disaster
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