A planned power increase from the first Japanese nuclear reactor restarted since the Fukushima meltdown has been delayed.
Kyushu Electric last week began the restart of the Sendai plant, the first of Japan’s reactors to begin operation under new safety standards introduced in the wake of the 2011 disaster.
Engineers and regulators have warned that the utility may encounter equipment problems and failures as the Sendai No. 1 reactor has been idled for more than four years.
The utility suspects that seawater has entered one of the pumps in the secondary cooling system, where steam that turns the turbines to produce electricity is cooled, according to the spokesman.
Kyushu Electric had planned to raise output from the reactor to 95 percent by Friday, but delayed the process.
It had planned to achieve full power by August 25 and begin commercial operation in early September after a final check from the atomic regulator.