Plant status 10am on the 8th Nov (Daiichi)
unit 3(water temperature of spent fuel
pool as of suspension: approx. 24.8°C). After finishing the reverse
cleaning of the primary strainer, then, at 7:17 pm on the same day we
restarted the alternative cooling (water temperature of spent fuel pool
as of restart: approx. 22.5°C *It is supposed that water temperature as
of restart became lower than that as of suspension because water in
skimmer surge tank was cooled down by outside air.
Unit 4 At 12:25 am on November 8, RO membrane unit of desalting facility in
spent fuel pool, Unit 4 automatically stopped due to the alarm
indicating leakage. Responding to the alarm, we confirmed that all the
isolation valves of each unit were closed by the interlocks. Also,
considering that all the spots at leakage risk were equipped with
receiving pans which would be able to store all of the liquid in the
unit, we judged that further deterioration of leakage or leakage to
outside of the unit was unlikely. We will check the site and situation
in the future. The operation of circulating cooling system has been
continued.
Other info At 2:55 pm on November 7, we started another boiler by using a spare
water transfer pump for boiler. Then, we started evaporative
concentration apparatus 3B at 5:24 pm and 3C at 6 pm. Causes of the
trouble of the water transfer pump for boiler are still under
investigation. At 2:24 am on November 8, we manually stopped the boiler
of evaporative concentration apparatus in the water desalinations since
alarm worked and indicated decrease of water level in boiler water
supply tank at 2:20 am. Then, we stopped evaporative concentration
apparatus 3B at 2:28 am ad 3C at 2:31 am. Although all the evaporative
concentration apparatus stopped, water treatment by the water
desalinations (RO membrane system) and water injection to the reactors
have been continued. Causes will be investigated in the future.
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