Roanoke Times
Copyright (c) 1995, Landmark Communications, Inc.
DATE: MONDAY, April 26, 1993 TAG: 9304260081
SECTION: VIRGINIA PAGE: C-2 EDITION: METRO
SOURCE: Associated Press
DATELINE: RICHMOND LENGTH: Medium
The valve in a steam line outside the station's nuclear reactor malfunctioned about 5:30 a.m. Saturday, damaging housings on the pipe and sending a fine cloud of insulation into the air, the company said.
The accident caused no injuries, the utility said.
When the valve was tested Sunday, employees found nothing wrong with it, utility spokesman James W. Norvelle said. Problems with the steam generator or electronic mechanisms may have caused the valve to malfunction, he said.
The nuclear plant has an automatic control system capable of giving a computer-generated sequence of the events that occurred, which will help determine the cause of the problem, company spokesman Carl F. Baab said.
The station's Unit 2 will remain shut down for several days, possibly longer, until the cause is determined, Baab said. North Anna's other unit is operating normally, he said. The utility predicted no problems meeting the demand for electricity.
The utility first reported the pipe had ruptured, spilling slightly radioactive steam. But Norvelle said workers apparently mistook the insulation dust for steam. They shut down the reactor and declared an alert at the power plant.
The plant has hundreds of such valves, which are made of a high-quality steel, Baab said.
The valve, which ordinarily remains open, apparently began opening and closing rapidly, Norvelle said. The action caused vibrations strong enough to be felt by Virginia Power employees in a control room some distance away, Norvelle said.
NRC officials stationed at the plant monitored the accident, and in a statement the agency said it sent two additional inspectors from a regional office in Atlanta.
by CNB