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Summary of incidents at nuclear facilities in FY 2009 (within the jurisdiction of METI)

The Nuclear and Industrial Safety Agency (NISA) announced today a summary of incidents that occurred at nuclear facilities in FY 2009.

1. In the event of an accident, a malfunction or another event (hereinafter "incident") specified in regulations related to the applicable laws (the Act on the Regulation of Nuclear Source Material, Nuclear Fuel Material and Reactors and the Electricity Utilities Industry Law) at a nuclear facility, its operator (electric power supplier, fabrication and enrichment company, reprocessing company, waste storage company, waste disposal company, etc.) is required to report it to NISA.

(1) The number of incidents reported with respect to nuclear power stations (54 reactors, not including those in the R&D phase) was 15*1 (compared to 23 in FY 2008). The average number of incidents reported per reactor was approximately 0.3 (approximately 0.4 in FY 2008).
(2) The number of incidents reported with respect to reactors in the R&D phase (reactors used for electric power generation-Monju and Fugen) was one (equivalent to the single incident reported in FY 2008).
(3) The number of incidents reported with respect to other nuclear facilities (facilities for fabrication and enrichment, reprocessing, waste storage, and waste disposal companies) was two (compared to five in FY 2008).
None of the above incidents resulted in any impact on the environment from radioactive substances.

2. These incidents were evaluated according to the International Nuclear Event Scale (INES).*2

*1: An accident that occurred on January 29, 2010 at the Sendai Nuclear Power Station of Kyushu Electric Power Co., Inc., is not counted as an accident at a nuclear facility because it was an electrical accident in a general electrical installation.
*2: Evaluation based on the INES User’s Manual 2001 Edition.

Evaluation results (including provisional evaluations)(number of cases)
INES Level 0- Level 0+ Level 1 Out of scale
Nuclear reactors 13 1 1 1
Other nuclear facilities 2 0 0

Release Date

April 16, 2010

Division in Charge

Nuclear Incident Response Office, Nuclear Emergency Preparedness Division, Nuclear and Industrial Safety Agency