27 avril 2011
Cette centrale a connu de sévères ennuis après les tornades qui se sont abattues dans la région le 27 avril 2011 : perte des alimentations électriques externes, baisse momentanée du niveau d’eau dans le réacteur n°1 ; utilisation des groupes électrogènes pendant 5 jours pour maintenir le refroidissement des réacteurs ; avant le rétablissement du réseau électrique endommagé, perte d’un générateur diesel de secours alimentant le système de refroidissement.
Available in english only.
At 1701 CDT, the licensee declared a Notification of Unusual Event under Emergency Action Level 5.1U due to loss of offsite power for >15 minutes. The loss of offsite power occurred at 1635 CDT and was due to severe weather and winds in the vicinity. When offsite power was lost, all 3 units automatically scrammed. The units are currently stable in Mode 3 with their respective 4KV busses being supplied by the onsite Emergency Diesel Generators[EDG]. The 161KV Athens line is the only offsite power source energized. All onsite safe shutdown equipment is available with the exception of the Unit 3 B EDG which was out of service for planned maintenance.
UPDATE FROM BILL BAKER TO HOWIE CROUCH AT 1942 EDT ON 4/27/11 The system actuations that occurred during the loss of offsite power were actuations of the Reactor Protection System, Primary Containment Isolation System (PCIS) and Emergency Diesel Generators. All primary containment valves actuated by the PCIS operated as expected. Unexpectedly, the Unit 3 "B" Main Steam Isolation Valve indicates intermediate.
Unit 1 High Pressure Coolant Injection actuated when reactor water level reached -45". Reactor Core Isolation Cooling (RCIC) was already initiated at the time.
UPDATE FROM BILL BAKER TO S. SANDIN AT 2153 EDT ON 4/27/11 Following the loss of offsite power only 12 of the required 100 offsite emergency sirens are operable.
The licensee will inform both state/local agencies and the NRC Resident Inspector.
Notified R2IRC (Wert) of this update.
UPDATE FROM BILL BAKER TO HOWIE CROUCH AT 2303 EDT ON 4/27/11
As a result of the loss of offsite power, the Diesel-driven Fire Pump auto-started. While the pump was running, the licensee discovered that approximately one quart of oil had leaked from the fire pump into the cold water channel which discharges into navigable waterways. The licensee confirmed this at 1950 CDT by visually identifying a sheen in the channel.
The licensee notified the National Response Center of the spill and, in accordance with their site discharge permit, notified the State of Alabama. This constitutes an 0ffsite Notification in accordance with 10CFR50.72(b)(2)(xi).
The licensee notified the NRC Resident Inspector. Notified NRC R2IRC (Wert).
UPDATE FROM BILL BUTLER TO HOWIE CROUCH AT 2338 EDT ON 4/27/11
At 2120 CDT, operators on Unit 1 were controlling reactor water level between 2 and 51 inches when RCIC became sluggish and water level dropped to +2" causing a valid RPS Scram signal as well as PCIS signals 2, 3, 6, and 8. All valves operated as expected and all isolations were completed.
The licensee notified the NRC Resident Inspector. Notified NRC R2IRC (Wert).
https://timesfreepress.com/news/2011/jul/14/tva-defends-browns-ferry-after-reports-equipment-o/
La boutique
Informez vous