Workers were evacuated from the disaster-hit Fukushima Daiichi nuclear plant on Wednesday after black smoke was seen rising from the most damaged reactor, plant operator Tokyo Electric Power Co. (TEPCO) said.
The smoke was spotted around 4:20 p.m. (0720 GMT) from the building houses No.3 reactor, TEPCO said, adding that it pulled out the workers from a shared central control room for the No.3 and No.4 reactors, as well as firefighters in the compound. The utility told reporters that smoke seems to be gradually fading away. No blaze was observed.
Due to smoke, the Tokyo Fire Department suspended a planned water-spraying operation to cool down the No.3 reactor’s fuel pool.
As an emergency measure to cool overheated spent-fuel rods, firefighters continue everyday spraying tons of seawater into reactors’ fuel storage pool. The Fukushima Daiichi nuclear power plant, 230 km north of Tokyo, hosts six nuclear reactors.
Among them, the No.3 unit is the only reactor that uses fuel containing plutonium and could release highly toxic plutonium in case of a meltdown.
The No.3 reactor was severely hit by an explosion on March 14, three days after the magnitude 9.0-earthquake and a 14-meter high tsunami damaged plant’s cooling functions.
Earlier in the day, the government’s Nuclear and Industrial Safety Agency said that TEPCO aims to restore a cooling pump at the No.3 reactor by Thursday. If the pump functions properly, TEPCO intends to begin cooling the reactor and its spent fuel storage pool, a major step to finally put the crisis under control.
On Tuesday evening, engineers restored the electricity supply to the No.3 reactor’s central control room for the first time in 11 days.
The revival of external power to the central control room — the heart of plant — allows workers to improve various intensive works, monitor radiation levels, temperature, water levels of the reactors and their spent fuel rod pools, and eventually reactivate their cooling functions.
Power lines also successfully reached all six reactors.