We would like to announce the current status of our Fukushima Daiichi and Daini Nuclear Power Stations after the earthquake (M7.3) which occurred at the offshore of Sanriku at around 5:18 PM on December 7.
As a result of patrols in Fukushima Daiichi and Daini Nuclear Power Stations performed yesterday, no problem was found with their equipments and facilities. Today, patrol was done in Units 5-6 outdoor seawater system and monitoring posts in Fukushima Daiichi Nuclear Power Station and no problem was found with them as well.
At Fukushima Daini Nuclear Power Station, the standby gas treatment system* was put in operation since the pressure in Unit 1 Reactor Building had turned positive (the pressure is usually kept negative against the outdoor air). In order to investigate the cause of this incident, the standby gas treatment system was suspended and the Reactor Building ventilation air conditioning system was started today. The pressure in the Reactor Building is being maintained in negative after switching the system. The cause of the incident will continue to be investigated.
* Standby gas treatment system: System that purifies the air in the Reactor Building utilizing high performance filter and discharge it to the outside through the exhaust stack. The system is comprised of systems (A) and (B).
© Tokyo Electric Power Company Holdings, Inc.
