Announcements
March 16, 2022 Earthquake Information (related to Fukushima Daini Nuclear Power Station)

March 17, 2022

Tokyo Electric Power Company Holdings, Inc.

Conditions at the Fukushima Daini Nuclear Power Station are as follows:

･ The tsunami had a no impact on power station facilities.
-Observed tsunami height: Approx. 0.2m
-Time of observation: 1:33 AM, March 17

･ In response to the tsunami warning that was issued for the coast of Fukushima Prefecture, no patrols below 12m above sea level were allowed after the earthquake. However, after the tsunami warning was lifted, the OK to commence patrols at lower elevations was given at 5:02 AM.

･ Status of patrols conducted after the earthquake:
-At 3:26 AM on March 17, it was confirmed that radiation concentrations in the water that overflowed from the Unit 4 spent fuel pool were below detectable limits.
-It was confirmed at 3:29 AM on March 27 that a blowout panel in the southwest corner of the Unit 1 reactor building was approximately one fist-width open due to deformation of the holding plate. Measures will be implemented to prevent the blowout panel from opening further.

･ All patrols implemented after the earthquake were completed as of 6:42 AM on March 17.
Equipment troubles found after this earthquake are as follows:
-The 500kV Tomioka line Unit 2 shut down as a result of equipment troubles at the Shin-Fukushima substation.
-A blowout panel in the southwest corner of the Unit 1 reactor building was approximately one fist-width open. It was confirmed that there was no discharge of radioactive substances into the exterior atmosphere. Furthermore, radiation concentrations inside the building are below detectable limits. A chain has been used to secure the blowout panel to ensure that it does not open further.
-Water from the Unit 4 spent fuel pool was found to have flown over the overflow prevention fence. The radiation concentration of the water that overflowed was below detectable limits.
-The cooling systems for the Unit 1 and Unit 3 spent fuel pools shut down automatically. Spent fuel pool cooling has recommenced and at current time spent fuel remains cool.

･ Patrols conducted after the earthquake have confirmed that spent fuel is being kept cool, and that the equipment troubles that were found have had no impact on plant operation. Therefore, the nuclear alert was lifted at 7:03 AM.