NRA weighs safety of idled Niigata reactors

Kyodo

Nuclear regulators on Thursday began assessing the safety of two reactors at Tokyo Electric Power Co.’s Kashiwazaki-Kariwa plant, nearly two months after the utility filed an application to restart them.

The move is a sign of progress for Tepco, which is eager to restart the seven-reactor plant in Niigata Prefecture to improve the tough business conditions it faces due to the crisis at its Fukushima No. 1 complex. Earlier, the Nuclear Regulation Authority suggested the process may not go smoothly.

Open safety screening meetings, which the NRA has convened dozens of times for other reactors, had not been held until Thursday for the Kashiwazaki-Kariwa plant. Tepco’s poor handling of the Fukushima No. 1 crisis has made regulators wary.

Ultimately though, NRA Chairman Shunichi Tanaka said, the agency could not continue to put off the screening process for reactors 6 and 7 now that documents submitted by the utility have been completely checked.

He also said that he viewed positively a recent announcement by Tepco that it had taken steps to improve the working conditions at the Fukushima plant, which could help the company to address mishaps caused by human error.

But Tanaka has warned that regulators may temporarily suspend the assessment process if serious problems occur at Fukushima No. 1. The screening period could also be prolonged because the two Kashiwazaki-Kariwa units are the first boiling water reactors to undergo safety assessments since Japan revamped its nuclear regulations in July.

Under the new safety requirements that reflect the lessons learned from the Fukushima crisis, 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, which are housed in containers larger than those of BWRs, giving more time until pressure rises inside the containers.

The activity of small geological faults beneath the two Kashiwazaki-Kariwa reactors could also become a contentious point, although Tepco has denied that the faults are active.

In quake-prone Japan, nuclear plant operators are not permitted to build reactors directly above faults that could move.

For Tepco, bringing its idled reactors back online would help it cut the huge cost of importing fuel for thermal power generation to meet electricity demand in Tokyo and surrounding areas.

The utility and a state-backed bailout fund have approached main creditor banks to seek about ¥2 trillion in fresh loans, sources close to Tepco said Thursday.

Tepco wants to secure the funds for capital investment, such as to renew its aging thermal power generation facilities, but financial institutions are expected to view the request skeptically, having already provided over ¥4 trillion in loans to the ailing company.

Fuel rods transferred

Tokyo Electric Power Co. on Thursday transferred the first batch of fuel rod assemblies pulled from the reactor 4 fuel pool at the crippled Fukushima No. 1 nuclear plant to another building with more stable storage conditions.

The move came three days after Tepco started a yearlong mission to eventually remove over 1,000 fuel assemblies from the spent fuel pool of the damaged reactor 4 building.

After filling a container with 22 unused fuel assemblies by Tuesday, workers on Thursday used a crane to lower the container from the fifth floor of the building housing the spent fuel pool to the ground about 32 meters below.

The container was then placed on a trailer and taken to a building about 100 meters away. There is a pool inside the building.