N-plants in Japan free from Y2K bug problems

TOKYO, Jan 2: Computer malfunctions at Japanese nuclear power plants, possibly connected with the Y2K bug, have all been cleared up and did not affect safety or power generation, company spokesmen said today, reports Reuters.

Five different problems, most connected with data monitoring, emerged at four separate nuclear plants on Saturday, marring Japan's otherwise good performance in the millennium handover.

But all had been solved by evening, a trade ministry official said today, adding that there were no new reports of any trouble.

Power company officials said they were still looking into the causes.

"It is too early to say with certainty that this was Y2K-related," added a spokesman for Tokyo Electric Power Co Inc 9501.T (TEPCO), Japan's biggest power utility.

At TEPCO's Fukushima Number 2 nuclear plant north of Tokyo, data on the position of the rods used to control nuclear reactions was not sent to the appropriate computer screen even though the data was present in the computer.

At no time was safety affected and the position of the rods was verified by other means until the problem was corrected on Saturday afternoon, the TEPCO spokesman said.

Investigations found that the computer had reset its date to February 2036. Technicians corrected the date and operations returned to normal, the spokesman said.

The longest-running glitch was at the Shika nuclear power plant run by Hokuriku Electric Power Co 9505.T about 300 km (186 miles) northwest of Tokyo, where problems were reported with a system used to send data on radiation emission and the state of the power plant to company headquarters and the government in case of emergencies.

A Hokuriku spokesman said this was cleared up by Saturday afternoon. "There is the chance that this was Y2K-related, but we need to investigate further," he added.

An alarm for a system processing meteorological data at Tohoku Electric Power Co's 9506.T Onagawa nuclear power plant in Miyagi Prefecture also went off soon after midnight, but order was restored 10 minutes later with no disruptions to power generation, government officials said.

A trade ministry official said ministry checks revealed that the same alarm had gone off several times in November and December as well, but that this was not publicly announced because it was regarded as too minor.