At 10:56 am on July 16, we started transfer of accumulated water from the vertical shaft, T/B, Unit 2 to Centralized Radiation Waste Treatment Facility (Process Main Building). At 4:04 pm on July 21, we stopped the transfer. - At 10:50 am on July 16, we started transfer of accumulated water from the vertical shaft, T/B, Unit 3 to Centralized Radiation Waste Treatment Facility (Process Main Building). At 3:59 pm on July 21, we stopped the transfer.
-At 8:43 am on July 22, because we confirmed that the amount of water injection had been lowered, we adjusted the amount to approximately 3.8m3/h.
- At 8:38 am on July 21, we stopped operation of the water treatment facility, because the water level gauge, which is set at suppression pool water surge-tank (B), was powered off due to the change of power sources associated with double circuit installation for offsite power at Unit 5 and 6. At 12:28 am on July 22, we started the operation of the water treatment facility, resuming water processing at 12:40 am on the same day.
-At 7:10 am on July 22, the circuit breaker for the bus from Okuma line 2L which supplies electricity to a part of power network in the power station opened the circuit due to overload, resulting in the power off of the following facilities: the alternative cooling facility for spent fuel pool at Unit 3, water treatment facilities, the cooling facility of common pool, monitoring gauges in the reactor of Unit 3 & 4, and Main Anti-Earthquake Building. The following facilities which receive power from other system had no affect: water injection and nitrogen gas injection to reactor of each unit, each monitoring post, the alternative cooling facility for spent fuel pool at Unit 2, monitoring gauges in the reactor of Unit 1 & 2, all facilities of unit 5 & 6. Currently investigations of the cause of the event as well as power restoration work are underway. After that, we found no abnormalities at the secondary side that have been tripped, we began receiving electricity from a power network line called TEPCO Genshiryoku Sen to complete the restoration works described below: -At 09:33 am Power source of Main Anti-Earthquake Building -At 10:35 am Monitoring instruments in Reactor of Unit 3 and 4 -At 10:40 am Cooling System of Common Pool -At 11:50 am Substitute Cooling Facilities at Spent Fuel Pool Cooling and Filtering System of Unit 3 -Water Treatment Facility is being prepared to restart operations.
For Main Anti-Earthquake Building, we restore its power supply immediately using backup power generator. For reference, this event did not affect the following operations: water injection and nitrogen gas injection to reactor of each unit, and data of each monitoring post.
Currently investigation of the cause of the event as well as power restoration work are underway.
- From 5:06 am to 6:02 am on July 22, dust sampling survey was implemented for the upper part of Unit 2's reactor building, using unmanned helicopter.
- Around 10:06am on July 18, a worker of the partner company fell from the height of about 3m during the connection work of the optical cable on the distribution pole near the power station's gazebo and he was injured. At 10:50 am, he was transported to J village by service car. We requested the helicopter emergency medical service (called "Doctor Heli") at 11:06 am. He was transported from multi purpose sports ground in Hirono town to the Iwaki Kyouritsu Hospital by the Doctor Heli at 12:22 pm. According to the result of physical examination, he was diagnosed as "fracture of distal end of right radius, of left radius head, and left ligamentum collaterale ulnare."