8 avril 2015
Cette fuite a été identifiée, lors de l’arrêt du réacteur pour son 18ème rechargement de combustible. Des examens visuels ont fait apparaître des dépôts blancs à proximité de l’aspiration de la pompe n° 2 de refroidissement du circuit primaire : une analyse isotopique de ces dépôts a montré qu’il s’agissait bien de liquide du circuit primaire. Le problème a été déclaré sur la base d’une dégradation d’une barrière de sécurité.
Type : PWR - Puissance : 3 990 MWth - Première divergence : 05/1971
Available in english only.
Event Number : 50968
Facility : PALO VERDE
State : AZ - Unit : [3] - RX Type : [3] CE
Event Date : 04/08/2015 - Event Time : 03:30
Emergency Class : NON EMERGENCY 10 CFR Section : 50.72(b)(3)(ii)(A) - DEGRADED CONDITION
Initial PWR : 100 % - Current PWR : 100 %
Event Text
REACTOR COOLANT SYSTEM PRESSURE BOUNDARY LEAKAGE IDENTIFIED
"The following event description is based on information currently available. If through subsequent reviews of this event additional information is identified that is pertinent to this event or alters the information being provided at this time, a follow-up notification will be made via the ENS or under the reporting requirements of 10 CFR 50.73.
"At approximately 0030 [MST] on April 7, 2015, while performing planned routine visual examinations of Unit 3 components, the differential pressure instrumentation nozzle on the suction side of the 2A reactor coolant pump (RCP) was observed to have white deposits that appeared to originate at the nozzle penetration. At this time, no additional indications of leakage have been identified for other inspected reactor coolant pressure boundary nozzles.
"Following insulation removal, the piping was examined by qualified engineering personnel. At 0330 [MST] on April 8, 2015, it was determined, based on isotopic analysis, that the white residue is consistent with reactor coolant system fluid. Technical Specifications Limiting Condition of Operation (LCO) 3.4.14 permits no reactor coolant system pressure boundary leakage and therefore, the discovery of leakage from the nozzle is a degradation of a principal safety barrier. This notification is being made for a degraded condition pursuant to the requirements of 10 CFR 50.72(b)(3)(ii)(A).
"The unit had been shutdown for its 18th refueling outage on 4/3/15 at 0000 [MST]. The NRC Resident Inspectors have been informed of this condition."
https://www.nrc.gov/reading-rm/doc-collections/event-status/event/2015/20150409en.html
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