Fukushima 50

Fukushima 50 is a pseudonym given by English-language media to a group of employees at the Fukushima Daiichi Nuclear Power Plant. Following the Tōhoku earthquake and tsunami on 11 March 2011, a related series of nuclear accidents resulted in melting of the cores of three reactors. These 50 employees remained on-site after 750 other workers were evacuated.^[1][2]

After TEPCO management proposed withdrawing all its employees from the plant on 14 March,^[3] additional manpower was deployed from around Japan.^[4] Some workers traveled on clear roads by convoy from Tokyo.^[4] When they arrived, hundreds of firemen, SDF personnel and employees of TEPCO, convened 20 km (12 mi) from the plant and debated how to best stabilize the plant.^[4] On the night of 15 March, these workers joined the original Fukushima 50. Despite the incorrect figure of workers, the Fukushima 50 has remained the pseudonym used by media to refer to the group of workers at Fukushima reflecting the solitary nature of the role.^[5]

The number of the workers involved rose to 580 on the morning of 18 March^[1] as staff from the Kashiwazaki-Kariwa Nuclear Power Plant and workers installing the new power line joined in. More than 1,000 workers, firefighters, and soldiers toiled at the site on 23 March.^[6] The Fukushima 50 were drawn from Toshiba, Hitachi, Kajima, firefighters from Tokyo, Osaka,^[7] Yokohama,^[8] Kawasaki, Nagoya and Kyoto, TEPCO and its subsidiaries such as Kandenko,^[9] TEP Industry and TEP Environmental Engineering, and many small-to-mid-size companies that have contracts with these big companies.^[1][10]

Over 20 workers had been injured by 18 March, including one who was exposed to a large amount of ionizing radiation when the worker tried to vent vapour from a valve of the containment building.^[1] Three more workers were exposed to radiation over 100 mSv, and two of them were sent to a hospital due to beta burns on 24 March.^[11] Two other workers, Kazuhiko Kokubo, 24, and Yoshiki Terashima, 21, were killed by the tsunami while conducting emergency repairs immediately after the quake. Their bodies were found on 30 March.^[12]

The workers and volunteers were assigned the mission of stabilizing the reactors. Their activities included assessing the damage and radiation levels caused by the explosions, cooling stricken reactors with seawater, and preventing any risk of fire. These workers remained on-site despite serious risks of radiation poisoning.^[13] Levels of radiation on site are far higher than in the 20 km (12 mi) exclusion zone and media outlets reported that the severity of the situation could have grave implications on their future health, with possibly fatal consequences for the workers.^[14] On 18 March, according to Prime Minister Naoto Kan the workers were "prepared for death".^[15]

On 14 March, a complete withdrawal proposed by TEPCO was rejected by the prime minister,^[16][17][18] to continue attempts at bringing the reactors under control during the Fukushima Daiichi nuclear disaster.