Oct 16 - McClatchy-Tribune Regional News - Dave Flessner Chattanooga Times/Free Press, Tenn.

Federal regulators said Monday they will reinspect TVA's oldest nuclear reactor in November after the unit shut down last week for the fifth time in as many months.

The Unit 1 reactor at Browns Ferry automatically shut down around 9 a.m. Friday when a turbine on the non-nuclear side of the plant tripped. TVA spokesman John Moulton said a review of the incident found that a transmitter associated with a moisture separator reheater failed, causing the turbine and then the reactor to shut down.

"The plant systems operated as designed and the unit will return to service after plant workers have completed the necessary work to return the reactor to service," he said.

Roger Hannah, a spokesman for the Nuclear Regulatory Commission, said the high number of unplanned reactor shutdowns since the Unit 1 reactor was restarted in May is causing the NRC to review plant operations again in early November.

The Unit 1 reactor at Browns Ferry was restarted in May following a 22-year outage. Since then, the unit's five unplanned shutdowns are more than 10 times the industry average for such unplanned outages during 2006, according to data compiled by the Nuclear Energy Institute.

"We'll be doing an inspection in early November when we are going to look at these trips in more detail and try to get more perspective on what is going on," Mr. Hannah said.

Ashok Bhatnagar, a TVA senior vice president who helped oversee the restart of Browns Ferry, said earlier this month that such shutdowns are not that unusual when a unit is returning to operation after an extended outage. In all cases, the safety systems have operated as designed, he said.

"Overall, I think the unit has performed well," Mr. Bhatnagar said.

Mr. Hannah said Browns Ferry Unit 1 has not operated long enough since its restart to come under the NRC's performance indicators for operating plants. Most of the unplanned outages have been only for a few days so the overall operating rate of the unit has been comparable with other Browns Ferry reactors restarted after extended outages, TVA officials said.

Since June, TVA estimates Browns Ferry Unit 1 has operated 84 percent of the time. During the comparable time after their initial restart, the Unit 2 reactor at Browns Ferry operated 86 percent of the time and Unit 3 operated 83 percent of the time.

TVA projects that Unit 1 will operate 93 percent of the time over its life.

E-mail Dave Flessner at dflessner@timesfreepress.com