31 mars 2013
Lors d’un test, le suintement d’un colorant a permis de détecter une fissure de 10 mm sur une soudure. Ce problème a été découvert sur une ligne de mesure dans le système de refroidissement principal du réacteur (RCS : "reactor coolant system"). Cette découverte a été classée comme "dégradation sérieuse."
1ère divergence : janvier 1975 – Type PWR
Available in english only.
Facility : COOK - State : MI - Unit : [1] - RX Type : [1] W-4-LP
Event Date : 03/31/2013 - Event Time : 04:14
Emergency Class : NON EMERGENCY 10 CFR Section : 50.72(b)(3)(ii)(A) - DEGRADED CONDITION
Initial PWR : 0 % Current PWR : 0 %
RCS FLOW INSTRUMENT LINE THROUGH WALL WELD DEFECT
"On 3/31/13 at 0414 EDT, dye penetrant testing identified a 10mm long relevant linear indication on a 3/4 inch RCS flow instrument line weld, between the RCS loop piping and the instrument isolation valve. This constitutes a weld defect in the primary coolant system that cannot be found acceptable per ASME Section XI. This section of piping is unisolable from the Reactor Coolant System. There is no evidence of active leakage currently or during the previous operating cycle, however, based on the dye penetrant testing this is considered a through wall leak.
"This event notification is being made in accordance with 10CFR50.72(b)(3)(ii)(A), as a condition that results in the condition of the nuclear power plant, including its principal safety barriers, being seriously degraded.
"Unit 1 is currently in a scheduled refueling outage in Mode 5 making preparations to transition to Mode 6. The plant is evaluating the appropriate repair method for this condition. The condition will be corrected during the current refueling outage. Unit 2 is in Mode 1 at 100% power and is unaffected by this condition.
"The NRC Resident Inspector has been notified."
https://www.nrc.gov/reading-rm/doc-collections/event-status/event/2013/20130401en.html
La boutique
Informez vous