Millstone 2 back online; plant to study water temperature

After being forced to shut one of its reactor units for about two weeks due to concern over water temperatures, Dominion’s (NYSE: D) Millstone nuclear plant in southern Connecticut is doing an analysis of the water temperature issue in Long Island Sound, a spokesperson confirmed Aug. 28.

Unit 2 was forced to suspend operation for about two weeks after water temperatures in the Sound had risen above 75 degrees F averaged over a 24-hour period. Unit 3 has a different design and was not affected by the water temperatures in Long Island Sound.

“If temperatures had continued to rise, it would have been required to shut down as well,” the spokesperson told GenerationHub.  Both units were back at full output as of Aug. 28. The dual-unit Millstone plant has a capacity of more than 2,000 MW.

“We are conducting an engineering analysis that would allow us to operate with higher water temperatures,” the Millstone spokesperson said. “That analysis won’t be complete until next year. It will go to the NRC [Nuclear Regulatory Commission] for review,” said the Millstone representative.

Both Millstone units have received 20-year license extensions from NRC. Millstone 2 is now licensed to operate through 2035 and Millstone 3 is licensed to run until 2045. Both reactors have refueling and maintenance outages scheduled during the next 12 months. Millstone 2 will be refueled this coming fall while Millstone 3’s next outage is set for the spring of 2013.

Unit 1 began commercial operation in December 1970, and ceased operating in July 1998. It is being decommissioned, according to a Dominion website. Millstone is located in southeast Connecticut, three miles west-southwest of New London

About Wayne Barber 4201 Articles
Wayne Barber, Chief Analyst for the GenerationHub, has been covering power generation, energy and natural resources issues at national publications for more than 20 years. Prior to joining PennWell he was editor of Generation Markets Week at SNL Financial for nine years. He has also worked as a business journalist at both McGraw-Hill and Financial Times Energy. Wayne also worked as a newspaper reporter for several years. During his career has visited nuclear reactors and coal mines as well as coal and natural gas power plants. Wayne can be reached at