Rokkasho Reprocessing Plant
The Rokkasho Reprocessing Plant is located in Rokkasho, a village in the district of Aomori Prefecture Kamikita Japanese.
Rokkasho is the site of a nuclear power industry center in Japan for the fuel cycle, which of the Nihon Gennen KK (English Japan Nuclear Fuel Limited, JNFL ) is operated.
On the grounds there are, among others, the following plants:
- Headquarters of JNFL
- A uranium enrichment plant (ウラン 濃縮 工場, uranium nōshuku Kojo ) with Centrifuge Technology (since 1992)
- A near-surface repository (since 1992)
- A reprocessing plant (六ヶ所 再 処理 工場, Rokkasho saishori Kojo ) for fuel from light water reactors ( since 2010)
The entire complex covers an area of 3.8 million square meters along the west bank of Lake Obuchi - numa and consists of 38 buildings (as of June 2010).
On 28 October 2010 started the construction of a plant for the production of MOX fuel.
Uranium enrichment plant
In Rokkasho a commercial enrichment plant was built, which is operated by JNFI (Japan Nuclear Fuel Industry Corporation ). The accumulation is done using the centrifuge technique. The first module with a capacity of 150 tons of uranium separative work (UTA ) per year went into operation in 1992, a year should be followed by another module. By September 1999, there were 1050 installed UTA t / a. When completed, the plant would have a capacity of 1500 t SW / a have. The technology of the plant is based on the experiences with a pilot plant (75 t SW / a, in operation since 1982) and a prototype plant (200 t SW / a, in operation since 1989 ) were obtained in Ningyo -toge Kagamino.
Reprocessing plant
In 1984 JNFS received (Japan Nuclear Fuel Services ), the construction license for a commercial reprocessing plant at Rokkasho. The capacity is 800 tons of heavy metal (t SM ) per year. The installation is completed. The input bearing has already been put into operation in 1997. The beginning of the reprocessing operation was scheduled for the end of 2005, the commercial operation should be incorporated in July 2006 and was postponed to mid-2010. Total to be re- worked in a period of 40 years, around 32,000 tonnes of spent fuel.
Repository
On the grounds of the center Rokkasho a near-surface repository for low -level radioactive waste has been constructed and put into operation in December 1992. The first stage of the repository capacity was 200,000 barrels ( corresponding to a volume of 40,000 m³). Meanwhile, the capacity was doubled by the construction of a second unit to 400,000 barrels ( corresponding to a volume of 80,000 m³). Until the end of March 2003, approximately 150,000 barrels ( 30,000 m³) were already incorporated. The storage area is divided into 8 groups of 5000 m³, each group consists of five concrete cavities. It is expected that this will be enough until the beginning of the next decade. The site conditions allow a further expansion of capacity up to 600,000 cubic meters (3 million barrels).
The barrels are stacked in large, concrete-lined chambers. The gaps are filled with concrete and the filled chamber is covered with a concrete layer, so that there is a monolithic block. This is covered with a thick layer of soil.
2011 earthquake
On 11 March 2011, the system had to change due to the heavy Tōhoku earthquake in 2011 his power to diesel-powered emergency generators. According to experts, the aggregates are " not designed to run long term." On March 14, 2011, the power supply has been restored.
7 April 2011 had to a aftershock of magnitude 7.1 again be cooled with diesel-powered emergency generators. The power supply was restored the following day.