Japan’s Nuclear Regulation Authority today informed the International Atomic Energy Agency that several systems that cool spent fuel pools at the Fukushima Daiichi Nuclear Power Station stopped working following a power outage that began at 19:00 local time yesterday.

Two of the systems – at Unit 1 and Unit 4 – were restarted today, and the system that cools the spent fuel pool of Unit 3 is set to be restarted at 20:00 local time today, according to the Authority. Work continues to restart the system that cools the Common Spent Fuel Pool.

The Authority reported that officials are watching the situation and that no abnormal radiation levels have been detected.

The operator, Tokyo Electric Power Company, is investigating the cause of the power outage.

The IAEA’s Incident and Emergency Centre remains in contact with the Japanese Nuclear Regulation Authority, and will provide updates when they become available.