Both Arkansas Nuclear One units now offline

With Unit 1 of the Entergy (NYSE:ETR) Arkansas Nuclear One facility having recently started its refueling and maintenance outage, Unit 2 is now offline to complete certain repairs.

ANO Unit 1 had started its 26th refueling outage on Sept. 24.

ANO Unit 2 was listed at zero power early Sept. 29 in Nuclear Regulatory Commission (NRC) data. The unit was listed at 100% the day before.

On Sept. 16, during a 24-hour technical specification endurance run, Unit 2 of Arkansas Nuclear One’s “red train Emergency Diesel Generator (EDG) became inoperable when its inboard generator bearing failed,” according to an event report with NRC.

Technical specifications require an emergency diesel generator to “be restored to service within 14 days or actions to place the unit in a shutdown condition initiated,” according to the event report.

“It has been determined that repair options cannot be completed within the Allowed Outage Time (AOT) due to unforeseen circumstances which evolved during recovery efforts,” according to the event report.

As a result, Unit 2 is being shut down to complete the repairs.

ANO Units 1 and 2 are pressurized water reactors (PWRs) located in Russellville, Arkansas. The two units have a combined generating capacity of about 1,800 MW.

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