8 avril 2020
Le 8 avril 2020 à 01 h 00 CDT, le réacteur de recherche de l’Université du Missouri-Columbia (MURR) a été arrêté en raison d’une défaillance du mécanisme d’entraînement des barres de contrôle qui ne permettait plus d’assurer sa régulation de sa puissance.
Le mécanisme d’entraînement des barres contrôle a été réparé et un test de leur opérabilité post-maintenance a été effectué. L’autorisation de redémarrer a été obtenue et le réacteur tourne à 10 MW.
Il s’agit d’une piscine ouverte, pressurisée, réfléchie et hétérogène, qui est modérée et refroidie par de l’eau légère.
Première divergence le 13 octobre 1966 à 5 MW - Autorisé à 10 MW en 1974.
Available in english only
Non-Power Reactor
Event Number : 54653 - Facility : UNIV OF MISSOURI-COLUMBIA
RX Type : 10000 KW TANK
City : COLUMBIA - State : MO
Event Date : 04/08/2020 - Event Time : 01:00 [CDT]
Emergency Class : NON EMERGENCY 10 CFR Section : NON-POWER REACTOR EVENT
Event Text RESEARCH AND TEST REACTOR FORCED SHUTDOWN DUE TO FAILURE OF REGULATING BLADE DRIVE MECHANISM
"On 4/8/20 at 0100 CDT, the University of Missouri-Columbia Research Reactor (MURR) was shut down due to a failure of the regulating blade drive mechanism to move the regulating blade during reactor operation. This email is a required notification per MURR Technical Specification (TS) 6.6.c.(1) to report to the NRC Operations Center that an Abnormal Occurrence, as defined by MURR TS 1.1, had occurred. Specifically, MURR was not in compliance with all Limiting Conditions for Operations (LCOs). MURR was not in compliance with two (2) LCOs : 1. TS 3.2.a states, ’All control blades, including the regulating blade, shall be operable during reactor operation,’ and 2. TS 3.2.f states, ’The reactor shall not be operated unless the following rod run-in functions are operable.’ Specifically, the rod run-in function that occurs when the regulating blade position is less than or equal to 10 percent withdrawn was not operable as TS 3.2.f.8 requires.
"The regulating blade drive mechanism was repaired, post-maintenance operability testing was conducted on the regulating blade, and permission from the Reactor Facility Director was obtained prior to the reactor returning to operation later on 4/8/20. Currently, MURR is at 10 MW. A detailed event report will follow within 14 days as required by MURR TS 6.6.c.(3)."
https://www.nrc.gov/reading-rm/doc-collections/event-status/event/2020/20200410en.html