Fukushima Daiichi NPS Prompt Report 2013

The reactor water injection line of Unit 2 at Fukushima Daiichi NPS was switched from the upland reactor water injection line to the CST reactor water injection line^* yesterday (July 3), and reactor water injection was being performed by the core spray system (approx. 3.5m³/h) and feed water system (approx. 2.0m³/h).

At 11:45 AM today (July 4), the valve installed at the reactor water injection line in the Turbine Building, which is connected to the CST reactor water injection line, was found to be opened. Therefore, some water, which was supposed to be flowed in the core spray system, was found to be flowed in the feed water system.

There is no change of the total water injection amount (approx. 5.5m³/h) of the core spray system and the feed water system, and the amount needed for the reactor water injection (4.0m³/h) is being maintained. No significant change of each parameter data has been found.

We will close the valve installed at the reactor water injection line in the Turbine Building, and will adjust the water injection amount today.

*Reactor water injection line of which the water source is the Condensate Storage Tank (CST).