6 janvier 2018
Cette perte de données entraine l’impossibilité d’action d’urgence en cas de survenue de rupture de tube de générateur de vapeur. De façon assez incroyable, ce sont encore (*) des mesures locales au compteur Geiger qui assurent le contrôle de la radioactivité de la ligne de vapeur.
(*) Un problème similaire s’est produit sur la même centrale en décembre dernier : https://www.sortirdunucleaire.org/Etats-Unis-Comanche-Peak-perte-intempestive-de
Type : PWR - Puissance : n° 1 : 3 612 MWth - n°2 : 3 458 MWth - Première divergence n°1 : 4 / 1990 - n° 2 : 3 / 1993 -
Available in english only
Event Number : 53154
Facility : COMANCHE PEAK
Region : 4 - State : TX - Unit : [2]
Event Date : 01/06/2018 - Event Time : 11:26 [CST]
Emergency Class : NON EMERGENCY 10 CFR Section : 50.72(b)(3)(xiii) - LOSS COMM/ASMT/RESPONSE
Initial PWR : n°1 : 100 % - n°2 : 100 % - Current PWR : n°1 : 100 % - n°2 : 100 % -
Event Text
MAIN STEAM LINE RADIATION MONITOR DETERMINED TO BE NON-FUNCTIONAL
"At 1126 [CST], main steamline radiation monitor 2-RE-2326 (Main Steamline 2-02) reading was determined to be erratic and was declared non-functional.
"With this radiation monitor non-functional, all of the emergency action levels for a steam generator tube rupture in steam generator 2-02 could neither be evaluated nor monitored. This unplanned condition is reportable as a loss of assessment capability per 10 CFR 50.72(b)(3)(xiii).
"Comanche Peak Nuclear Power Plant [CPNPP] has assurance of steam generator integrity and fuel cladding integrity and there is a negligible safety significance to the current condition from a public health and safety perspective.
"Additionally, compensatory measures are in place to assure adequate monitoring capability is available to implement the CPNPP emergency plan in the unlikely event of challenges to the steam generator or fuel cladding. The N16 [Nitrogen-16] radiation monitor serves as a backup with alarm function and Radiation Protection technicians have been briefed on taking local readings with a Geiger-Mueller tube on MSL [Main Steam Line] 2-02.
"Corrective actions are being pursued to restore 2-RE-2326 to functional status.
"The NRC Resident Inspector has been notified."
https://www.nrc.gov/reading-rm/doc-collections/event-status/event/2018/20180108en.html