Japan Press Weekly

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2011 May 25 - 31 [NUCLEAR CRISIS]

Reprocessing of nuclear spent fuel is perilous endeavor

A nuclear spent fuel reprocessing plant is a facility for extracting uranium and plutonium from spent fuel produced at nuclear power stations. It is dubbed a “radiochemistry plant” as it deals with a massive amount of radioactive materials, but its reprocessing technology is still immature and is even more dangerous than nuclear power generation itself.

The Rokkasho plant located in Rokkasho Village in Aomori Prefecture is one such plant. Japan Nuclear Fuel Ltd. completed the construction of the plant in 1997 and began its test runs in 2001. “Active tests” using spent fuel were launched in 2006.

However, its operation has been under suspension since December 2008 due to frequent accidents and numerous problems, including a leakage of radioactive liquid waste, internal exposure of workers to radiation, and a discovery of quake-resistant design errors.

Japan Nuclear Fuel Ltd. explains that the radioactive byproduct called “death-ash” will be stored as high-level radioactive waste for 30-50 years in special containers to cool down, and then will be buried deep in the ground. The company has so far found no prospect of where to establish an underground nuclear-waste repository.

At reprocessing factories abroad, accidents involving chain reactions of nuclear fission and explosions took place one after another. A similar plant in Tokai Village, Ibaraki Prefecture, run by former Power Reactor and Nuclear Fuel Development Co. (currently, Japan Atomic Energy Agency) also caused an explosion accident in 1997, resulting in the exposure of 37 workers to radiation.

The Rokkasho plant operator has explained that nothing was found to be wrong at the plant when it inspected it for earthquake-proof safety on the assumption that an M-8.3 earthquake occurs underwater about 130km away from the plant site as well as an M-6.9 quake triggered by movements of a nearby active fault occurs.

However, some researchers point out that another active fault, which may also cause an M-8 class earthquake, has been discovered underwater much closer to the plant than the company simulated.

An M-8 quake in distant underwater and a near-field M-8 quake would entail different shake intensities, researchers warn. However, Japan Nuclear Fuel Ltd. has ignored this warning so far.

Ichikawa Fujio, former researcher at the Japan Atomic Energy Research Institute, assumes that the government wants to get the plant on track at any cost because of its policy to reprocess all spent nuclear fuel for nuclear recycling.

Ichikawa expressed concern, “Although many minor accidents and troubles have taken place at the Rokkasho plant, we hardly hear anything from engineers working there. Maybe they are being forced to be quiet.”