At the time of the earthquake, units 1, 5 and 6 were down for scheduled maintenance. The remaining four units powered down safely in response to the earthquake as per protocol. TEPCO wanted to resume operations the day following the earthquake, but was ordered to keep Kashiwazaki-Kariwa powered down by the Ministry of Economy, Trade and Industry METI. The International Atomic Energy Agency IAEA conducted an inspection of the power station, concluding that no significant damage had been sustained and that TEPCO should re-evaluate seismic safety.
Kashiwazaki-Kariwa remained down for 21 months and was brought back online in May 2009, after Unit 7 was deemed seismically fit to resume operations. Units 6 and 1 soon followed.
According to recent information provided by TEPCO, units 1 and 7 have resumed normal operations, and Unit 5 is undergoing a full-capacity test run. Unit 5 is expected to enter normal operations very soon, and Unit 6 is down for scheduled maintenance. BWR units 2, 3 and 4 are still down and under inspection with no definite restart dates.
In the next year, units 7 and 6 are expected to undergo scheduled inspection and refueling. Part of the inspection will include an earthquake resistance examination. Unit 7 will be powered down for three months from the third quarter of 2011 to the fourth quarter of 2011, while Unit 6's three-month outage is expected to take place starting in the first quarter of 2012. Total investment value for inspection and refueling is expected to be about $218 million per unit.