16 juin 2015
Alors que le réacteur était à 100% de sa puissance, deux porte coupe-feu entre le bâtiment des auxiliaires du réacteur et la ligne de vapeur principale ont été ouvertes. Suite à un problème de vapeur qui serait survenu dans sa ligne de transport, le bâtiment des auxiliaires aurait été confronté à des conditions de température, de pression et d’humidité élevées, supérieures aux conditions de qualification des matériels. Ces équipements liés à la redondance de la sécurité auraient été rendus indisponibles, ce qui aurait menacé des dispositifs chargés de limiter les conséquences d’un accident. Il a été déterminé que ces conditions de fonctionnement anormales, produites sous contrôle administratif vers le support de maintenance ont été reproduites plusieurs fois en mai et juin.
Type : PWR - Puissance : 2 900 MWth - Première divergence : 10/1987
Available in english only.
Event Number : 51178
Facility : HARRIS - State : NC - Unit : [1] - RX Type : [1] W-3-LP
Event Date : 06/16/2015 - Event Time : 11:45
Emergency Class : NON EMERGENCY 10 CFR Section : 50.72(b)(3)(ii)(B) - UNANALYZED CONDITION 50.72(b)(3)(v)(D) - ACCIDENT MITIGATION
Initial PWR : 100 % - Current PWR : 100 % -
Event Text
UNANALYZED CONDITION DUE TO OPEN HIGH ENERGY LINE BREAK DOORS
"On June 16, 2015 at 1145 EDT while in Mode 1 at 100% power steady-state conditions, two fire doors between the Reactor Auxiliary building (RAB) and steam tunnel were opened under administrative controls to support maintenance. These doors are credited in high energy line break equipment qualification and internal flooding analyses and opening of the doors is not addressed in the analyses. A high energy line break in the steam tunnel with the doors open could result in equipment in the RAB experiencing high temperature, pressure, or humidity beyond conditions analyzed for equipment qualification which has the potential to render redundant safety-related equipment inoperable.
"The event was determined to be reportable on June 24, 2015 at approximately 1550 [EDT]. During that reportability evaluation, it was determined that the doors may have been in a similar condition multiple times in the May-June time frame.
"This condition is reportable in accordance with 10 CFR 50.72(b)(3)(ii)(B) as an unanalyzed condition and in accordance with 10 CFR 50.72(b)(3)(v)(D) as a condition that could have prevented the fulfillment of the safety function of structures or system that are needed to mitigate the consequences of an accident.
"There was no adverse impact to public health and safety or to plant employees."
The NRC Resident Inspector has been notified.
https://www.nrc.gov/reading-rm/doc-collections/event-status/event/2015/20150625en.html#en51178
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