Nine accidents similar to the steam pipe rupture that killed four workers at a nuclear power plant last week have occurred at other reactors, a safety panel revealed Thursday.

The findings were reported by the Nuclear and Industrial Safety Agency at a meeting of the Ministry of Economy, Trade and Industry's Advisory Committee for Natural Resources and Energy.

The committee held its second round of discussions looking into the cause of the Aug. 9 accident at the No. 3 reactor at Kansai Electric Power Co.'s Mihama nuclear plant in Fukui Prefecture.

An aging pipe in a turbine facility at the reactor burst, showering workers with superheated steam. In addition to the four fatalities, 11 other workers were injured. There was no radiation leakage.

According to the nuclear safety agency, there have been nine incidents at nuclear reactors involving pipes eroded by coolant water, just as in the Mihama accident. It reported there were another seven pipe accidents at thermal reactors.

In the Mihama accident, the faulty pipe section, which had not been inspected since the reactor started up in 1976, had worn as thin as 0.6 mm.

It was also reported that pipes had not been properly inspected at 17 areas in six of Kepco's nuclear reactors.