Hamaoka Nuclear Power Station:Cause and Countermeasures Concerning Fire from Office Air Conditioner Power Panel

Chubu Electric Power investigated what caused the fire that took place on March 8, 2017, from the power panel of the air conditioner (AC) in Hamaoka Nuclear Power Station's office workroom, and compiled countermeasures accordingly.

Following the investigation, the fire was presumed to have been a result of incorrect wiring inside the power panel of a newly installed workroom AC. An excess current likely ran through and either damaged or burned multiple components inside the power panel circuit.

The possible cause of incorrect wiring was identified to have been a lack of management of wire distribution. It appears that this occurred when the plant-wired and inspected AC was undergoing disassembling and re-wiring on station sites.

In light of this event, whenever Chubu Electric Power is to engage in similar work it will, at the timing of procurement, call on contractors to use checksheets and make double-checks. The company will prevent fire from recurring by verifying said checksheet before moving on to subsequent steps.

Chubu Electric Power has verified that the wiring of nuclear safety equipment is managed on the field.