At around 6:57 PM on March 18, there was an incident where the power supply facilities in the Main Anti-earthquake Building at Fukushima Daiichi Nuclear Power Station momentarily stopped.
Upon investigation, the following facilities were confirmed to be suspended.
- Common pool cooling purification system
- Nitrogen supply equipment (Nitrogen separator B)*
*After confirming the soundness of the power supply, the equipment was started at 3:00 AM on March 19 and nitrogen supply was started at 3:10 AM. Nitrogen injection had continued while the equipment was suspended as the other nitrogen supply equipment (nitrogen separator A) was in operation.
No problem has been found with the following facilities.
- Units 1-3 nitrogen injection systems
- Nitrogen supply equipment (Nitrogen separator A)
Since it takes a certain amount of time for the spent fuel pool/common pool water temperatures to increase, the temperatures will not immediately reach the maximum allowed temperature (65℃). The amounts of time to reach the maximum allowed temperature (65℃) are as follows.