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Etats-Unis : Lasalle : Utilisation de soudures non conformes sur un couvert de vanne




13 mars 2015


Les défauts de soudure ont été découverts lors du remplacement d’une vanne de 61 cm de diamètre sur le circuit de recirculation. La soudure a été remise en conformité. Aucun autre défaut de sous-dimensionnement n’a été repéré sur des vannes livrées à d’autres sites.

Type : BWR Mark 2 - Puissance : 3 456 MWth - Première divergence : 03/1984

Available in english only.


Event Number : 50888

Rep Org : WEIR VALVES AND CONTROLS USA INC.

Licensee : WEIR VALVES AND CONTROLS USA INC.

Event Date : 03/13/2015 Event Time :

Emergency Class : NON EMERGENCY 10 CFR Section : 21.21(d)(3)(i) - DEFECTS AND NONCOMPLIANCE Person (Organization) :

Event Text

IMPROPER WELD USED ON GATE VALVE COVER

The following was received from the licensee via email :

"This notification is being submitted pursuant to the guidelines of 10 CFR Part 21 to report that, during the manufacturing of a replacement cover for a 24 inch gate valve on the reactor recirc line at Exelon LaSalle, Weir Valves and Controls used a weld that was not compliant to ASME Ill Subsection NB requirements.

"During review of the weld at site, the question was raised based on site procedures required a 2:1 profile in accordance to EPRI guidelines. During review of the documentation to determine if the 2:1 profile was required in this case, Weir Valves and Controls determined that improper weld call out was used on the design prints. The weld was corrected at site to meet the both ASME Ill Subsection NB requirements and EPRI guidelines.

"Weir Valves and Controls has performed an extent condition review and has concluded that no other undersized welds were made and delivered to any other operating sites.

"The root-cause of the issue was the improper call-out of the weld by design engineering.

"Weir Valves and Controls is performing corrective actions to ensure future re-occurrences cannot occur in design engineering."

http://www.nrc.gov/reading-rm/doc-collections/event-status/event/2015/20150316en.html#en50888