The Tomari 3, a 912-MW pressurized water reactor (PWR) at Hokkaido Electric Power Co.’s Tomari plant in northern Japan’s Hokkaido region, has resumed full commercial operation. It is the first reactor in the country to be restarted after a periodic inspection following the March 11 earthquake and tsunami that caused the Fukushima nuclear disaster.

The Tomari 3—a unit that was connected to the grid only in December 2009—has been operating at full capacity in testing status as part of the final phase of inspection since March 7, days before the Fukushima crisis began. Hokkaido Electric Power has since enhanced safety measures at the plant in response to the nuclear crisis. On Aug. 10 it completed the first stage of the two-phase stress test and received a certificate for completing a periodic inspection today. The start of commercial operation of Tomari 3 was announced by Hokkaido Gov. Harumi Takahashi, Japanese news agency Kyodo reported.

After the natural disasters on March 11, the Japanese government ordered all 35 reactors that had been shut down for regular safety checks (out of a total of 52 reactors) to stay offline until given permission to restart after rigorous “stress tests.”

Tomari 3 is scheduled to undergo inspection in spring 2012. Tomari 1, a 550-MW PWR has also been shut down for periodic inspection, while Tomari 2 is currently operating but due to be shut down for inspection later this month.

Japan is considering phasing out nuclear power in the long-term and is considering the possibility that all of Japan’s 54 reactors could be shut down by May 2012. The Ministry of Economy, Trade and Industry, however, has said it wants to resume reactor operations amid a summer electricity crunch.

Sources: POWERnews, Kyodo, Reuters