OI, FUKUI PREF. - Kansai Electric Power Co.’s No. 4 reactor at its Oi nuclear plant in Fukui Prefecture inched closer toward running at full capacity Thursday, four years and eight months after operations were suspended.
The reactor has reached criticality, its nuclear fission chain reaction having reached a self-sustaining state, and is set to begin power generation and transmission Friday. It is projected to reach full capacity early next week.
The reactor, which was halted in September 2013 for regular checkups, is the eighth to have been reactivated under the country’s new safety standards for nuclear plants. The new standards were introduced in the wake of the March 2011 triple meltdown at Tokyo Electric Power Company Holdings Inc.’s tsunami-stricken Fukushima No. 1 nuclear plant.
Kansai Electric plans to put the No. 4 reactor into commercial mode in early June and cut its electricity prices this summer.
Commercial operations of the No. 3 and No. 4 reactors at the Oi plant are projected to help reduce the firm’s fuel costs by about ¥120 billion a year. The No. 3 unit was brought back online in March this year and entered commercial mode in April.
The utility lowered its electricity rates for households by 3.15 percent on average in August 2017, after it resumed commercial operations of the No. 3 and No. 4 reactors at its Takahama plant in Fukui Prefecture.
As each of the two Oi reactors has a capacity of 1.18 million kilowatts — larger than the 870,000 kilowatt capacity of each of the Takahama reactors — the forthcoming rate cut may be more significant than the previous one and could bring the company’s electricity prices down to levels from before the Fukushima nuclear accident, industry observers said.
Kansai Electric owns 11 reactors — four each at the Oi and Takahama plants, and three at the Mihama plant, also in Fukui Prefecture.
Besides the four currently in operation, the Mihama No. 1 and No. 2 units and the Oi No. 1 and No. 2 units are set to be decommissioned. The Mihama No. 3 unit and the Takahama No. 1 and No. 2 units are undergoing work to allow them to continue to operate after reaching 40 years of service.
With the Oi and Takahama plants located as little as 13.5 kilometers from each other, the plant operator has been urged to draw up measures that should be taken in case accidents occur at the same time at the two facilities.
This summer the government plans to carry out a comprehensive anti-disaster drill assuming simultaneous accidents.