Panel: Fault under nuclear reactor may have moved — NHK World

” A panel of experts will present a draft of a report on a fault running under a nuclear reactor in central Japan on Friday. Its findings could lead to the possible decommissioning of the reactor.

The panel plans to disclose the draft at a meeting of the Nuclear Regulation Authority, or NRA, on Friday.

The report deals with a fault under the No.1 reactor at the Shika nuclear power plant in Ishikawa Prefecture, operated by Hokuriku Electric Power Company.

It says there is no clear evidence that the fault called S-1 is active. But it also says the strata above the northwestern part of the fault may have moved after a geological period called the Late Pleistocene. That’s between 120,000 and 130,000 years ago.

The experts cite a sketch of the strata drawn before the reactor’s construction as well as simulations involving nearby faults.

The draft says strata believed to have accumulated after the Late Pleistocene period may have slid because of movement in the fault.

Japan’s new regulations ban constructing reactor buildings and other key nuclear plant facilities above a fault that may have moved after the Late Pleistocene period.

The reactor could be scrapped if the expert panel and the NRA determine that the fault could be potentially active. ”


Spent-nuclear fuel issues plague restarts — The Japan Times

” Spent fuel at the Hamaoka nuclear power station in Shizuoka Prefecture could exceed the capacity of storage pools some two years after the plant is restarted — much sooner than the previously assumed eight years, according to sources.

The faster pace is because the storage pools for reactors 1 and 2 at the Chubu Electric Power Co. plant will be removed from the complex’s total storage capacity following the decommissioning of the two units.

Previously, Chubu Electric planned to continue using the two reactors’ storage pools. The operations of the two reactors ended in 2009.

Last month, four power suppliers, including Kansai Electric Power Co., decommissioned a combined five aging reactors, significantly reducing storage pool capacity.

As of the end of March, the Hamaoka plant’s storage capacity fell by 440 tons in the past six months to 1,300 tons, reflecting the exclusion of the reactor 1 and 2 pools, according to Chubu Electric’s semiannual report to the Federation of Electric Power Companies. Meanwhile, the amount of spent fuel stored at the plant stood at 1,130 tons.

If the remaining three reactors at the plant are brought back online, the amount of spent fuel would exceed the storage capacity in 2.3 years, compared with the eight years estimated before the company’s decision not to use the reactor 1 and 2 pools.

Of all 15 domestic nuclear plants that operators are seeking to restart, storage space capacity appears to be lowest at the Hamaoka plant.

Only four of the plants have more than 10 years before they run short of capacity, including Hokkaido Electric Power Co.’s Tomari plant, which has the longest time, at 16.5 years. The three others are Tohoku Electric Power Co.’s Higashidori plant, with 15.1 years, Hokuriku Electric Power Co.’s Shika plant, with 14.4 years, and Kyushu Electric Power Co.’s Sendai plant, with 10.7 years.

All nuclear reactors in Japan are now offline.

Some nuclear plant operators are working to increase their spent-fuel storage capacities while pinning hopes on fuel recycling at Japan Nuclear Fuel Ltd.’s facilities in the village of Rokkasho, Aomori Prefecture.

Chubu Electric has applied to build a dry-cooling storage facility at the Hamaoka plant to boost its total capacity to store spent fuel. It hopes to put the facility into operation in fiscal 2018 if the plan is approved by the Nuclear Regulation Authority.

A Chubu Electric official said storage capacity prospects remain unclear at the plant because it is uncertain if any reactors will be allowed to restart. ”


Experts say faults under Japan nuclear plant may be active — Kyodo News

” Geological experts on a panel under the Nuclear Regulation Authority said Wednesday that faults running beneath a nuclear plant in central Japan may be active, clouding the prospects for resumption of its operations.

Four outside experts of the five-member panel told a meeting it is possible the fault running right under the No. 1 reactor at Hokuriku Electric Power Co.’s two-unit plant in Shika, Ishikawa Prefecture, is active.

If the regulator finalizes the judgment based on the panel’s opinion, the utility would have no option but permanently shutting down that unit. …”