NEWS RELEASE                                                                              

May 23, 2003
Contact:  Jim Warren 
919-416-5077                                                                                                     

More Emergency Shutdowns of Harris Nuclear Reactor

Spate of Malfunctions Thwart Reactor Restart; One Triggers Special Inspection Team

DURHAM, NC – The Shearon Harris nuclear reactor suffered at least three emergency shutdowns in the past week as operators tried to resume full power after a month-long refueling outage.  A fourth system failure occurred last Friday while the plant was still off-line for refueling.  Still another, and possibly the most serious problem, happened in late April when a valve in the primary cooling system failed during the refueling period, which triggered a special investigation by the U.S. Nuclear Regulatory Commission (NRC).

The string of failures comes on the heels of four emergency shutdowns and other plant problems last year.   The industry average is one shutdown, or “SCRAM,” per 18 months.  Reports to the NRC from plant owner Progress Energy indicate that causes of the latest problems are still under investigation. The agency will later determine their safety significance, and whether to lower Harris to a second-tier safety ranking, as happened last year.

David Lochbaum, nuclear safety engineer for the Union of Concerned Scientists, said today that risks at a nuclear plant are usually determined by unknown factors.  He said Harris’s problems could be caused by worn out or aging equipment, personnel error, or improper calibration of instrumentation.  “Either could be of concern.  The danger comes when an initiating event such as these trips of the reactor are followed by either an operator error or another compounding factor.”  He added that such a combination of factors are what led to the meltdown at Three Mile Island in 1979, and the disastrous explosion of the Chernobyl reactor in 1986.

Harris had been scheduled to resume full power production late last week after workers replaced fuel in the reactor core and performed scheduled maintenance on the overall power plant.  Restart was delayed last Friday when a back-up cooling pump was activated during testing of the primary cooling system.  The next three setbacks happened as the reactor was being powered back up.  A turbine problem Sunday, May 18^th, was followed by a failure of primary cooling for the reactor on Tuesday, which activated back-up cooling pumps; both events caused emergency shutdown of the reactor.  

Last night, the reactor was up to 72% power when it tripped again due to vibrations in the main cooling water system.  A Progress spokesman said the vibration might have been caused by a faulty part replaced during the recent maintenance.

Earlier this month, a special NRC team spent two weeks at Harris investigating the April 26 malfunction of a relief valve in the primary cooling system that caused an interruption of core cooling, reportedly for five minutes, early in the refueling process.

Even when a nuclear reactor is off-line, large amounts of water must be circulated to keep the reactor core from overheating.  While the reactor vessel head is off for weeks during refueling, the heat generated in the core is not being removed by steam generators as it normally is when the plant is operating.  Buildup of heat in the system could leave little time for operators to correct a loss of core cooling before the water boils and allows  radioactive steam to escape from the containment dome, which is not intact during refueling.

Lochbaum pointed out that NRC studies show nuclear plants are far more dangerous during refueling, in part due to an industry trend to take measures to shorten the refueling outage in order to save money: “Safety comes before economics in the industry's press releases but not in their practices.”

A further factor regarding heat removal capacity is that at Harris, waste fuel storage pools are cooled by the same system that cools the reactor, although this was not the original design for the plant.

NC WARN has not yet determined whether Shearon Harris leads the industry in emergency reactor shutdowns.

Lochbaum explained, “All these problems show that Harris is beating the odds … I’m sure it’s not a trophy Progress Energy would want.” 

Progress’s Rick Kimble said he anticipated the plant being back to full power by tonight.  The additional outage is costly for the company because it reduces the amount of electricity sales. 

Lochbaum added a caution:  “If you had a car that broke down three times before it got out of the driveway, would you think it's ready for the highway?”