The 9 August incident, as reported by EnergyReview.net, was the result of aging pipe at a turning facility at the Kansai Electric Power Co’s (KEPCO) plant rupturing and showering nearby workers with superheated steam. Aside from the four fatalities, 11 other workers were injured.

In a statement the Agency said, “There have been nine incidents at nuclear reactors involving pipes eroded by coolant water, just as in the Mihama accident. [And] there were another seven pipe accidents at [other] 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. [Furthermore,] pipes had not been properly inspected at 17 areas in six of KEPCO’s nuclear reactors,” it added.

The findings of the Agency were forwarded to Japan’s Ministry of Economy, Trade and Industry's Advisory Committee for Natural Resources and Energy.

KEPCO has already publicly apologised for the incident.