More signs of progress were seen in Japan’s desperate efforts to cool overheated spent-fuel rods at the disaster-stricken nuclear power plant on Monday, with the plant operator aiming to restore external power to reactors’ central control rooms later in the day, while temperatures at all six spent fuel rod pools continued to fall.
Tokyo Electric Power Co. (TEPCO), an operator of Fukushima Daiichi (No.1) nuclear power plant, resumed work to restore external power to the No.3 and No. 4 reactors, which are still without electricity.
The operation followed after water-spraying missions early monitoring by the Tokyo Fire Department and Self-Defense Forces to those two reactors to cool down their spent fuel rod pools.
The government’s Nuclear and Industrial Safety Agency said Monday that external power to the No.2 reactor’s central control room may be resumed later in the day, paving the way for TEPCO to start monitoring various measurement devices and lighting systems and checking for electricity leakage in the battery charging room.
But it may take a few more days to restore the No.2 reactor’s cooling system, given that as some parts replacements are needed in the electrical system, the agency said.
The Fukushima plant, which houses six nuclear reactors, located 230 km north of Tokyo. Of the six, the No.1, No.2 and No.3 reactors were operating at the time of the March 11 magnitude 9.0 quake and shut down automatically and lost their cooling functions.
External power already reached the electricity distribution facilities of the No.2 and No.5 reactors on Sunday, and power can now be supplied to the No.1, No.2, No.5, and No.6 reactors.
The No.5 and No.6 reactors, which have been relatively less problematic, successfully stopped on Sunday.
The No.3 and No.4 reactors, where high levels of radiation are forcing workers to exercise extreme caution, are scheduled to be connected to the electricity distribution panels on Tuesday.
Restoring electrical power to the central control rooms is a crucial step that allows operator to resume vital cooling systems for the reactor vessels and the spent fuel rod pools.
Meanwhile, Defense Minister Toshimi Kitazawa said Sunday night that the temperatures of the fuel rod pools at all six reactors were fell below the boiling point, thanks to water-spray operations since Thursday by troops and firefighters.
The Nuclear and Industrial Safety Agency also said the operations appear to be paying off to a certain degree, with radiation levels showing a continuous decline since Sunday afternoon.
A series of explosions have severely damaged buildings of reactors as well as the No.2 reactor’s containment vessel. Plutonium-uranium mixed oxide fuel in the No.3 reactor poses the greatest risk with the threat of releasing highly toxic plutonium in the event of a meltdown.