28 juillet 2017
Le niveau d’oxygène est passé en dessous de 18,4% ce qui est en dessous du seuil d’habitabilité. Ce niveau faible est lié à une fuite d’azote à l’intérieur du confinement. L’azote a été isolé du confinement qui va être purgé par les opérateurs. L’alerte a été levée 6 h 13 après son déclenchement suite au rétablissement de l’atmosphère du confinement dans de bonnes valeurs .
Type : PWR - Puissance : 3 411 MWth - Première divergence : 8 / 1985 -
Available in english only
Event Number : 52876
Facility : DIABLO CANYON - State : CA - Unit : [2] RX Type : [2] W-4-LP
Event Time : 12:06 [PDT] - Last Update Date : 07/28/2017
Emergency Class : ALERT 10 CFR Section : 50.72(a) (1) (i) - EMERGENCY DECLARED
Initial PWR 100 % Current PWR 100 %
Event Text
ALERT DECLARED DUE TO LOW OXYGEN LEVELS INSIDE CONTAINMENT
"Containment atmosphere oxygen level was measured at 18.4 percent. This is below normal habitability level. The cause of the low oxygen level is a nitrogen leak inside containment Nitrogen has been isolated from containment and operators are preparing to purge containment."
The licensee notified the State of California, local authorities and the NRC Resident Inspector.
Notified the DHS SWO, FEMA OPS, USDA OPS, HHS OPS, DOE OPS, DHS NICC, EPA EOC. Notified FDA EOC, NuclearSSA, FEMA NWC and FEMA NRCC SASC via email.
* * * UPDATE FROM ALLEN DURACHER TO VINCE KLCO ON 7/28/17 AT 2142 EDT * * *
The ALERT was terminated on 7/28/17 at 1819 PDT. The containment atmosphere was restored to normal conditions. The nitrogen source was isolated. The cause of the nitrogen leak into containment is under investigation.
The licensee will notify the NRC Resident Inspector. The licensee has notified the State of California and the local authorities. The licensee plans to issue a press release.
Notified the R4DO (Hay), NRR EO (Miller), IRD MOC (Grant).
Notified the DHS SWO, FEMA OPS, USDA OPS, HHS OPS, DOE OPS, DHS NICC, EPA EOC. Notified FDA EOC, NuclearSSA, FEMA NWC and FEMA NRCC SASC via email.
https://www.nrc.gov/reading-rm/doc-collections/event-status/event/2017/20170731en.html