March 16, 2022 Earthquake Information (related to Fukushima Daiichi and Fukushima Daini Nuclear Power Stations)
March 17, 2022
Tokyo Electric Power Company Holdings, Inc.
･ At around 11:36 PM on March 16, 2022, an earthquake occurred off the coast of Fukushima Prefecture.
･ The status of the Fukushima Daiichi Nuclear Power Station is as follows:
<As of 2 AM, March 17>
Units 1~6 facility plant parameters No abnormalities
Reactor cooling water injection equipment (Units 1~3) No abnormalities
Spent fuel cooling equipment (Units 1~6, common pool) No abnormalities
- From around 1 AM on March 17, continuous dust monitors inside the Unit 2 reactor building indicated a decreasing trend.
3.7×10^-3 Bq/cm3 ("High" alarm value: 1×10^-3 Bq/cm3)
-As of 1 AM on March 17, a decreasing trend has been seen in values indicated by on-site continuous dust monitors on the Unit 1/2 slope, Unit 1 ocean side, and Unit 3 ocean side.
No significant fluctuation has been seen with any other on-site continuous dust monitors.
-At 1:30 AM, March 17, a decreasing trend was seen with on-site drainage channel monitor indicators (unloading wharf).
-We have confirmed that Unit 5 spent fuel pit cooling facilities automatically shut down in conjunction with the earthquake.
-Our assessment of the temperature of water for Unit 2 and Unit 5 spent fuel pit cooling facilities, which are currently shut down, is as follows:
(Unit 2) Limiting condition for operation of 65°C has not been reached.
(Unit 5) It would take approximately 11 days to reach 65°C, which is the limiting condition for operation.
-A small leak of approximately one drop every several minutes has been found from the hydraulic pump for the filtrated pure water device sludge device, and we have confirmed that this dripping oil has been stopped by closing a valve. (Amount of leak: 50cm x 50cm x 1mm).
-Puddles have been found on the Unit 5 and 6 reactor building operating floors. It is assumed that the puddles were caused by sloshing of the spent fuel pools as a result of the earthquake.
(Location) Unit 6 reactor building operating floor: 4 locations
(Time of discovery) Around 2:20 AM
(Scope of leak) Southwest: 0.3m x 0.5m x 1mm
Southeast: 0.2m x 0.2m x 1mm
Northeast: 0.2m x 0.2m x 1mm
Northwest: 0.2m x 0.2m x 1mm
(Location) Unit 5 reactor building operating floor: 4 locations
(Time of discovery) Around 2:35 AM
(Scope of leak) Southwest: 5.0m x 5.0m x 1mm
Southeast: 1.0m x 0.5m x 1mm
Northeast: 1.0m x 0.5m x 1mm
Northwest: 1.0m x 0.5m x 1mm
Unit 5 and 6 continuous dust monitors have shown no significant fluctuations.
-At 2:45 AM on March 17, a drop in the water level (55mm/hour) of the Unit 6 turbine auxiliary cooling system (pure water) tank was observed. More information is currently being gathered.
-No other abnormalities, such as leaks, etc., have been found at current time.
-At 2:45 AM on March 17, a leak the thickness of approximately two pencils was found from the bolt that secures the bottom of the existing desalination equipment ultra filter cleaning water tank. The water tank has been isolated and it has been confirmed that the leak has been contained by the dikes.
Scope of leak: 6m x 6m x 1m (the water that leaked is desalinated freshwater).
-At 2:50 AM on March 17, high ground patrols found that some paint on the walls of the J5 tank and G6 tank areas has peeled back. No leaks were found in the aforementioned tank areas.
-At 3 AM on March 17, displacement of the strontium-removed water tank (H8-A3) was found. No leaks were found from the connecting pipes, and no significant fluctuation was seen in the water level of the tank.
･ The status of the Fukushima Daini Nuclear Power Station is as follows:
<Status of patrols implemented after the earthquake>
-At 2:15 AM on March 17, it was found that water had flowed over the overflow prevention fence at the Unit 4 spent fuel pool. The amount of water that overflowed is approximately 0.0003 liters. No overflow or leaks were found from the Unit 1~3 spent fuel pools.
-At 2:19 AM on March 17, one of the blowout panels in the southwest corner of the Unit 1 reactor building was found to be a fist-width open. The negative pressure inside the building is being maintained, and it has been confirmed that there were no leaks of radioactive substances into the external atmosphere.
-At 2:42 AM on March 17, one fire truck from the Tomioka Fire Department arrived at the front gate (sirens blaring).
-At 2:57 AM on March 17, Tomioka Fire Department personnel determined that all fire alarms on-site were false alarms.
-At 3:01 AM on March 17, the fire truck left the premises.
-No significant fluctuations have been seen in readings from exhaust stack monitors or monitoring posts.