A steam leak at No. 3 reactor in Mihama, Fukui has left at least four dead and seven injured on August 9. Mihama had been shut down by hand in 2002 for a leak in a facility next to the reactor. The Kansai Electric Power Co., KEPCO, which runs three nuclear power plants in Fukui have recently been eager to add a storage facility – check Japan Times article.
Previous problems
The Japan Nuclear Energy Safety Organization, JNES, carries information on incidents and failures for plants in Japan. You can find a direct link to the Mihama Power Station here.
Incidents for No. 3 include:
Nov. 15, 2002 – Manual shutdown
Nov. 15, 2000 – Defect found during periodic inspection
Sep. 1, 2000 – Defect found during periodic inspection
May 27, 1999 – Defect found during periodic inspection
Oct. 19, 1998 – Power reduction
Oct. 13, 1995 – Manual shutdown
May 12, 1995 – Troubles discovered during periodic inspection
Apr. 20, 1994 – Manual shutdown
KEPCO aware of risk
It seems that KEPCO was aware that the pipes could wear as thin as they did at Mihama No. 3 plant for over a decade. Despite this and a warning from the inspection firm in November the pipe remained uninspected. You can check Japan Times, or check Mainichi.