Wisconsin Nuclear Plant Shut Down

Paraphrased by:
Steve Waldrop
January 23, 2004

Federal inspectors and Kewaunee Nuclear Plant employees are trying to find out how silt and lake weeds were able to clog head exchangers for an emergency cooling system at the facility.

The Kewaunee plant was shut down as an investigation of the problem continued. The shutdown of the plant was not expected to affect electricity supplies.

The heat exchangers are used to cool the oil that lubricates the plant's safety injection pumps. The safety injection system provides emergency cooling at the plant and the problem could prevent proper cooling of the reactor in the event of an accident, said the Nuclear Regulatory Commission.

The regulatory commission said that it has launched a special inspection of the plant. Two inspectors arrived to examine the sequence of events that led to the clogging.

Inspectors will assess whether there were "indications that could have helped the utility to identify the problem earlier," a commission spokeswoman said.

The problem didn't surface during a test that evaluates the integrity of the exchanges. That test measures how much water is flowing through the exchangers' tubes.

Although those flow tests showed everything to be normal, plant workers found the problem when they noticed silt and weeds in the tubes of the heat exchangers. Tests showed that 17 of 20 inlets in each heat exchanger were clogged.

The 535-megawatt Kewaunee plant is one of six Upper Midwest nuclear plants operated by Nuclear Management Company based in Hudson, Wis. The plant is owned by Wisconsin Public Service of Green Bay and Alliant Energy of Madison, Wisconsin.

The Kewaunee Nuclear Power Plant is located along Lake Michigan in the town of Carlton, nine miles south of Kewaunee, Wisconsin and about 35 miles southeast of Green Bay, Wisconsin. The plant began commercial operations in 1974 and has approximately 450 employees.

It is unknown how long the facility will remain shut down.