 INES [N/A] |
CARBON DIOXIDE RELEASE TO A PLANT VITAL AREA |
The plant was operating at 100% power when a release of carbon dioxide (CO2) to a plant vital area occurred. The area was immediately evacuated, and there were no personnel injuries nor any effect on plant safety systems. The CO2 bottles are located in an auxiliary builiding room and are used for a fire suppression system in an adjacent cable spreading room. The release occurred due to improper thread engagement during the performance of a surveillance test procedure on the back-up bank of bottles. The test procedure requires the bottles to be dis-connected, weighed, and then re-connected. The primary bank of CO2 bottles remained available for fire protection. The emergency event was terminated when all areas of the auxiliary building were verified to have oxygen concentrations of greater than 20%. The plant remained at power throughout the event.
On 134 February 1995, Robinson Unit 2 was operating at 100% power.
During the performance of a surveillance test on a fire suppression system for a cable spreading room in the auxiliary building, a carbon dioxide release occurred. In response the licensee declared an ALERT due to the release of a toxic gas into a vital area.
The area was immediately evacuated, and there were no personnel injuries nor any effect on plant safety systems. The emergency event was terminated following confirmation that the carbon dioxide was of insufficient quantity to present a respiratory hazard inside the building. The plant remained operating at 100% power throughout the event.
Rating basis:
The event is rated out of scale in accordance with paragraph I.1.3 of the INES users' 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: Mon, 13-02-1995
