Waterford 3 was operating at 93% when a potentially hazardous gaseous release from a nearby chemical plant threatened the site. The control room ventilation system was placed in the recirculation mode during the event. On-site personnel at Waterford 3 were sheltered, and there were no evacuations from the site. Sheltering was terminated a half-hour after the initial chemical release, and the event was terminated within four hours. Waterford 3 continued operating at 93% throughout the event. The gaseous release was subsequently confirmed to be non-toxic.
On 25 March 1995, Waterford Unit 3 was operating at 93% power. The licensee declared an ALERT due to a potentially hazardous release from a nearby chemical plant. The control room ventilation system for Waterford
Unit 3 was placed in the recirculation mode in response to the release. The unit did not receive any toxic gas monitoring alarms.
Sheltering of Waterford Unit 3 on-site personnel was implemented during the release. The event was down-graded a half-hour after the inital release, and terminated within four hours. There were no evacuations of on-site personnel, and Waterford 3 continued operating at 93% power throughout the event.
Basis for rating:
The event is rated "out of scale" in accordance with Paragraph I.1.3 of the INES user's manual. This paragraph defines the scope of the scale, and states in part, that such events are termed out of scale "when they do not involve any possible radiological hazard and do not affect the safety layers". This event had no effect on safety-related equipment.
Event date: Sat, 25-03-1995