Some facilities of Shika Nuclear Power Station had received damage from the 2024 Noto Peninsula Earthquake, but critical function such as off-site power and cooling facilities, and no issues have arisen for securing the safety of reactor facilities.
Here are some current photos of the main facilities.
Due to earthquake on January 1, spent fuel storage pool water was scattered onto the floor, but and did not impact radiation levels outside, and scattered water has been wiped clean.（Unit 1：about 95 liters、Unit 2：about 326 liters）
Pool level has not changed significantly, and cooling pumps are operating normally, and there is no impact on capabilities to cool spent fuel.
Annunciator “expansion difference large” was set-off at the shutdown Unit 2 low pressure turbine, but does not impact securing safety of nuclear facilities.
The turbine is currently being inspected to determine if there is any internal damage.
Due to the earthquake on January 1, the protection circuit of Unit 2 main transformer was activated and automatically switched to standby transformer. Recovery of insulating oil leaked from main transformer was completed on January 5 (Insulating oil: approx. 19,800 liters (approx. 24,600 liters including water)).
Oil film that may have been caused by insulating oil flowing out in the sea area in front of the power station has been confirmed twice so far, and the following actions have been taken. In both cases, there were no abnormalities in oil leak detectors, etc. in radiation control area, and there was no external radioactive impact.
・The one confirmed on January 7 has been treated with a neutralizing agent, etc.
・For the one confirmed on January 10, the drainage gate was closed and an oil fence was installed in the coastal area.
Currently, insulating oil leakage point of main transformer is covered with blue sheets to prevent rainwater intrusion.
Due to the earthquake on January 1, the protection circuit of main transformer was activated and automatically switched to standby transformer.
Currently, power is received from standby transformer, and no issues have arisen for securing the safety of reactor facilities.
Due to the earthquake on January 1, Oil leakage from Unit 1 startup transformer was confirmed, and on the same day switchover operation to alternative backup transformer was conducted.
Recovery of insulating oil leaked from startup transformer was completed on January 2 (approx. 4,200 liters including sprayed fire water).
Unit 1 startup transformer was temporarily restored after removal of damaged radiator and replacement of parts, and began receiving power on March 14.
Two of the five off-site power transmission lines to Shika Nuclear Power Station were compromised (Shika Naka Noto Line 2 lines), but three lines (Shika nuclear power line Unit 1 line, Shika nuclear power line Unit 1 line, Unit 2 line, Akasumi line) are still online for Shika Nuclear Power Station Unit 1 and 2.
Currently, both Units 1 and 2 receive power from Shika nuclear power line.
Emergency diesel generators (Unit 1: 3 units, Unit 2: 3 units) are secured as backup power sources for external power sources.
Two high capacity power cars are deployed as backup power sources for external power supplies.
Eight high voltage power car (one of which is undergoing inspection) are deployed as backup power sources for external power supplies.
Metallic cover, which protects the rubber sealing material (expansion) connecting Units 1 and 2 waste treatment buildings detached, but there was no damage to sealing material and there was no radiological impact outside.
Emergency response center with a seismically isolated structure, equipped with an independent power supply, etc., has been established as a base of operations in the event of an accident or other incident.
Emergency response center expansion (command area) is located next to Emergency response center, which has even better shielding, earthquake resistance, and fire protection measures than Emergency response center.
The response after the Noto peninsula earthquake was conducted in the command area of Emergency response center.
There is no damage to Otsubo river dam (360,000 m3 ), which is water source required for cooling spent fuel, and Large-capacity freshwater storage tanks (4,900 m3 on the east side and 5,100 m3 on the south side) as backup water sources, and there are no problems in securing water sources.
Seven monitoring posts have been installed near the power station site boundaries to constantly measure and record airborne radiation dose rates and are monitored centrally in main control room.
Measurements have been taken normally before and after the earthquake, and it was confirmed that there has been no external radiation impact to date.
The main roads on Shika NPS were not damaged, therefore there were no obstacles to vehicular traffic, etc.
The prefectural road in front of Shika NPS was not damaged, therefore there were no obstacles to vehicular traffic, etc.
The town road on the east side of Shika NPS was not damaged, therefore there were no obstacles to vehicular traffic, etc.
