TEPCO July 25 press releases about suspension of cooling

Press Release (Jul 25,2013)Suspension of Reactor Cooling During the Logic Verifying Test of Unit 6 Emergency Diesel Generator at Fukushima Daiichi Nuclear Power Station (Follow-up Information 2)

http://www.tepco.co.jp/en/press/corp-com/release/2013/1229226_5130.html

This is a follow-up report on the statuses of suspension of the residual heat removal B system after the 6.9 kV metal-clad (power panel) C at Unit 6 was suspended during the logic verifying test (automatic starting test) of Unit 6 emergency diesel generator at Fukushima Daiichi Nuclear Power Station at around 10:16 AM today (July 25).

At 12:06 PM, the residual heat removal B system and cooling of the reactor was restarted. After that, emergency gas treatment system A was suspended at 12:32 PM and emergency gas treatment system B was suspended at 12:34 PM, since air conditioning of the Reactor Building was restarted at 12:22 PM. No abnormality was found in the operation status after the restart of the air conditioning.

The water temperature of the reactor as of 13:00 PM is 28.0℃, which is stable.

We will continue to investigate the cause of the suspension of the residual heat removal B system.

Press Release (Jul 25,2013)Suspension of Reactor Cooling During the Logic Verifying Test of Unit 6 Emergency Diesel Generator at Fukushima Daiichi Nuclear Power Station (Follow-up Information)

This is a follow-up report on the statuses of suspension of the residual heat removal B system after the 6.9 kV metal-clad (power panel) C at Unit 6 was suspended during the logic verifying test (automatic starting test) of Unit 6 emergency diesel generator at Fukushima Daiichi Nuclear Power Station at around 10:16 AM today (July 25).

At 12:06 PM, we have restarted the residual heat removal B system and cooling of the reactor.
No abnormality was found in the operation status after the restart of the system.

The water temperature of the reactor as of 12:00 PM is 27.6℃, which is sufficiently lower than the maximum allowed temperature (100℃). We are currently investigating the cause of the suspension of the residual heat removal B system.

Press Release (Jul 25,2013)Suspension of Reactor Cooling During the Logic Verifying Test of Unit 6 Emergency Diesel Generator at Fukushima Daiichi Nuclear Power Station

At around 10:16 AM today (July 25), the residual heat removal B system, which was cooling the reactor, has stopped after the 6.9 kV metal-clad (power panel) C at Unit 6 was suspended during the logic verifying test (automatic starting test) of Unit 6 emergency diesel generator at Fukushima Daiichi Nuclear Power Station.

Currently, we are proceeding with the preparation to restart the reactor cooling by the residual heat removal B system, and it is expected to be restored within about an hour.

The other statuses are as follows.

- Air conditioning of the Reactor Building has stopped, and the emergency gas treatment system^* has started.
(The negative pressure of the Reactor Building is being maintained.)
- Cooling system of the spent fuel pool is operating continuously.
- Water temperature of the reactor as of 10:43 AM is 27.1℃. The increase rate of reactor water temperature is estimated to be approx. 1℃ per hour.

* Emergency gas treatment system
A device, which closes regular ventilation system automatically and maintains the negative pressure inside the Reactor Building as well as removing radioactive iodine and particle radioactive material in the building utilizing charcoal filter, high performance particle filter, etc. to reduce the emission of radioactive material to the environment in case radioactive leakage accident occurs in the Reactor Building.

We are now confirming the status and preparing toward restoration, and will announce the status as soon as we know it.

___________________________________