OKUMA, FUKUSHIMA PREF. – Nuclear disaster minister Goshi Hosono on Saturday visited the Fukushima No. 1 nuclear plant and inspected work to reinforce the reactor 4 spent-fuel pool, which contains a large number of fuel rods, and protect it against major temblors.
Hosono told reporters afterward that he felt the buttressed structure beneath the pool appears secure.
The No. 4 reactor was offline for maintenance when the nuclear disaster erupted in March 2011 and the pool’s 1,535 nuclear fuel assemblies have been maintained in a cool and stable state.
However, a hydrogen explosion that month blew away the upper part of the building’s outer wall and the spent-fuel pool remains exposed to the elements.
Hosono also climbed to the upper level of the five-story building and was briefed by officials from plant operator Tokyo Electric Power Co. on efforts to reinforce the storage pool.
Radiation levels on the fifth floor were between 100 and 300 microsieverts per hour at the time of Hosono’s visit, according to Tepco.
Hosono said his first internal inspection of the unit had enabled him to fully grasp the treacherous working conditions inside for the first time. Simply climbing the set of makeshift, narrow stairs to reach the upper levels must be “very tough for workers clad in protective gear,” he noted.
The minister also observed preparatory work to decommission the power stations’ crippled units, including a crane built to remove fuel rods from the reactor 4 pool beginning next year, based on Tepco’s plans.
Reporters from both domestic and overseas media outlets toured the facility aboard a bus the same day, and were allowed to get off and inspect the No. 4 reactor from a distance of around 70 to 80 meters.