Today at 2:46PM, turbines and reactors of Tokyo Electric Power Company's
Fukushima Daini Nuclear Power Station Units 1 to 4 (Boiling Water Reactor,
rated output 1,100 Megawatts) that had been operating at rated power
automatically shutdown due to the Miyagiken-oki Earthquake.
Currently, reactor water level for Units 1 to 4 is maintained by injecting
water into the reactors by the Reactor Core Isolation Cooling System.
The reactors are maintained at a subcritical condition.
For Unit 1, the emergency core cooling system automatically started up
due to increase in the reactor containment pressure assumed to be caused
by leakage of reactor coolant in the reactor containment.
Hence, at 5:35PM, it was decided that a specific incident stipulated in
Article 10, Clause 1 of the Act on Special Measures Concerning Nuclear
Emergency Preparedness *1 has occurred.
At 5:50PM, pursuant to the Act, relevant governmental institutions were
notified of the incident.
Future Actions: TEPCO is taking measures to reduce the pressure of the reactor containment.
Impact to safety and external environment:
Water level to cool the irradiated nuclear fuel in the reactor core is
maintained at this moment.
Indication of the monitoring posts installed in the periphery of the power
station is no different from usual and thus no radiation impact to the
external environment is confirmed at this moment.
We will continue to monitor in detail the possibility of discharge of
radioactive material from exhaust stacks and coolant water discharge canal.
. . . .