It looks this plant has been built by shaving off the tops of the mountains.
From Wiki English:
The Rokkasho Reprocessing Plant (六ヶ所村核燃料再処理施設, Rokkasho Kakunenryō Saishori Shisetsu ) is a nuclear reprocessing plant with an annual capacity of 800 tons of uranium or 8 tons of plutonium, owned by Japan Nuclear Fuel Limited located in the village of Rokkasho in northeast Aomori Prefecture, Japan approximately 17 miles (27 kilometers) north of the US Air Force's Misawa Air Base. Since 1993 there has been US$ 20 billion invested in the project, nearly triple the original cost estimate. It is currently[when?] undergoing test operations, separating a small amount of used nuclear fuel. It is the successor to a smaller reprocessing plant located in Tōkai, Ibaraki.
At the same site there will also be:
- A high level nuclear waste monitoring facility
- A MOX fuel fabrication plant
- A uranium enrichment plant
- A low level radioactive waste landfill
In 2010, the Rokkasho Reprocessing Plant consisted of 38 buildings on an area of 3,800,000 m². After the Tōhoku earthquake in March 2011, the plant ran on emergency power provided by backup diesel generators. The emergency generators were not intended for long-term use. Reportedly there are about 3,000 tons of highly radioactive used nuclear fuel stored in Rokkasho at current, that could overheat and catch fire if the cooling systems fail.
Gleaning more info from the Japanese wiki:
The plant is built with assistance from France. (AREVA, most likely.)
The plant has been running a "active test run" since March 31 of 2006. The test run was supposed to be over by January of 2009, but it still continues. The plant has been besieged with various accidents ever since it started the "active test run".
There is a very strong opposition against this particular plant. Greenpeace Japan (link is in Japanese) has said that the radioactive materials that would be released from the plant in one day is equivalent of the radioactive materials that would be released from a nuclear plant in one year.
O M G. From the Plant's own website:
Meanwhile, we received 93 tons of spent fuel in the current fiscal year, and 3,258 tons of spent fuel in total are stored up now.
So it's 3,258 tons.
and 13,272 spent fuel rods, according to their Japanese website.