Fukushima No. 3 Reactor's Meltdown Occurred Earlier: TEPCO

Tokyo, Aug. 6 (Jiji Press)--Tokyo Electric Power Co. <9501> said Wednesday that the core of the No. 3 reactor at its disaster-stricken Fukushima No. 1 nuclear power plant is now believed to have melted about five hours earlier than previously estimated. According to TEPCO's latest analysis, nuclear fuel in the No. 3 unit reached the melting point of 2,200 degrees Celsius around 5:30 a.m. on March 13 (8:30 p.m. on March 12 GMT), 2011, two days after the plant in northwestern Japan was crippled by a 9.0-magnitude earthquake and ensuing tsunami. TEPCO initially thought that cooling water injection into the reactor with a high pressure core flooder system had continued until the system was manually switched off shortly before 3 a.m. on March 13, but it now sees the possibility that the water injection stopped around 8 p.m. the previous day. The operator of the power plant in Fukushima Prefecture also said most of the melted nuclear fuel penetrated the No. 3 reactor's pressure vessel and dropped down to the outer containment vessel. The melted fuel is estimated to have eroded the concrete-made reactor container by 68 centimeters, much deeper than the 20 centimeters estimated in November 2011, TEPCO said. But the company denied that the fuel went through the containment vessel to reach the soil. END