KYODO NEWS - Oct 4, 2017 - 14:15 | All

Two reactors in Niigata Prefecture on the Sea of Japan coast run by the operator of the crippled Fukushima nuclear plant cleared government safety standards on Wednesday, becoming the first of the utility's idled units to pass tightened screening.

The Nuclear Regulation Authority endorsed at its meeting a draft document that serves as certification that Tokyo Electric Power Company Holdings Inc.'s Nos. 6 and 7 reactors at Kashiwazaki-Kariwa power station have met the new, stricter safety standards introduced after the Fukushima disaster.

The two reactors are the newest among the seven units at the Kashiwazaki-Kariwa plant. The complex is one of the world's largest nuclear power plants, with a combined output capacity of 8.2 million kilowatts.

Despite the effective approval by the nuclear regulator, the actual restart of the two reactors will likely be at least a few years away as Niigata Gov. Ryuichi Yoneyama says it will take "around three to four years" for the utility to win local consent for the resumption of operation.

Formal approval of the restart by the nuclear watchdog is expected after receiving public opinions and consulting with the economy, trade and industry minister to confirm that Tepco is fit to be an operator.

The clearance of the two units is likely to be a boost for the government of Prime Minister Shinzo Abe, which is keen to retain nuclear power generation despite Japan suffering the world's worst nuclear disaster since Chernobyl at the Fukushima Daiichi nuclear complex in March 2011, triggered by a massive earthquake and tsunami.

Tepco, facing huge compensation payments and other costs stemming from the Fukushima crisis, has been desperate to resume operation of its idled reactors so it can reduce spending on costly fossil fuel imports for non-nuclear thermal power generation.

It filed for safety assessments of the two idled reactors at Kashiwazaki-Kariwa plant in September 2013.

In addition to assessing technical requirements, the review focused on whether Tepco is qualified to once again operate a nuclear power plant as it struggles with work to scrap the Fukushima Daiichi complex, an effort expected to take until around 2051, and reduce contaminated water around the crippled plant where radiation levels remain high.

The two reactors are boiling-water reactors, the same as those that experienced meltdowns in the Fukushima crisis. No such types have previously cleared Japan's safety standards after the Fukushima disaster, partly as they are required to conduct major refurbishment to boost safety.

Under the new safety requirements, BWRs must be equipped with filtered venting systems so that radioactive substances will be reduced when gas and steam need to be released to prevent damage to containment vessels.

The venting facilities are not an immediate requirement for pressurized water reactors as PWRs are housed in containers larger than those of BWRs, giving more time until pressure rises inside the containers.

In the review, the regulator had questioned Tepco on its posture to ensure the safety of the units. The company last month agreed to a request from the regulator to include a safety pledge as part of its legally binding reactor safety program.

Safety programs drawn up for reactors need to be approved by the regulator and if it finds a grave violation, it can demand the utility halt nuclear power operations.