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Title: Present status and future plans for the restoration of Fukushima Daiichi NPS

Conference ·
OSTI ID:22257928
 [1]
  1. Tokyo Electric Power Company 1-1-3 Uchisaiwai-cho, Chiyoda-ku, Tokyo 100-8560 (Japan)

There are many challenges at Fukushima-Daiichi Nuclear Power Station, even though the reactors have reached a condition equivalent to cold shutdown. Cooling of reactors is maintained using the circulating cooling system, which contains some temporary equipments and consists of long pipes reaching to about 4 km. The reliability of the cooling system is one of the keys to maintaining the stabilized condition. Therefore a variety of activities, such as the replacement of hoses with more durable pipes, is being conducted to improve the reliability of the cooling system. The first fuel bundle will be removed from the spent fuel pool (SFP) at Unit 4 in November, which is earlier than the original plan. In preparation for the fuel debris removal, investigations inside the primary containment vessel (PCVs) have been initiated. Visual images and other data, such as water level, radiation dose and temperature inside the PCVs, have been taken at Units 1 and 2. The issue of excessive contaminated water is the most urgent one. About 400 tons of ground water is intruding into the turbine and reactor buildings every day. This intruding water mixes with the core cooling water and becomes a large amount of contaminated water. It has to be stored on the site, despite the fact that some radioactive nuclides remain in it even after cesium is removed. The amount of water stored on the site has reached about 290,000 tons so far and is increasing. Counter measures for this issue, such as reduction of intruding water, cleaning up of the contaminated water and securing of water storage tanks, are under consideration and being conducted. However, certain recent events, such as the power loss of the SFP cooling systems and leakage of contaminated water from the underground tanks, have raised concerns about reliability. Vulnerabilities have been evaluated systematically and counter measures are being taken. (authors)

Research Organization:
American Nuclear Society, 555 North Kensington Avenue, La Grange Park, IL 60526 (United States)
OSTI ID:
22257928
Resource Relation:
Conference: GLOBAL 2013: International Nuclear Fuel Cycle Conference - Nuclear Energy at a Crossroads, Salt Lake City, UT (United States), 29 Sep - 3 Oct 2013; Other Information: Country of input: France; 3 refs.; Related Information: In: Proceedings of GLOBAL 2013: International Nuclear Fuel Cycle Conference - Nuclear Energy at a Crossroads| 1633 p.
Country of Publication:
United States
Language:
English