ENS 51701

v t e ENS Event
21:18 Jan 29, 2016
Title	Specified System Actuation After Loss of One Offsite Power Source
Event Description	On January 29, 2016, at 1518 CST, with the plant in cold shutdown, power was lost on reserve station service (RSS) line no. 1. This is one of two sources of offsite power required by Technical Specifications. The power loss de-energized the Division 1 onsite AC safety-related switchgear, causing an automatic start of the Division 1 emergency diesel generator (EDG). The Division 1 reactor protection system (RPS) bus was also de-energized, causing a half-scram signal. Approximately 8 minutes later, a full actuation of the RPS occurred due to a high water level condition in the control rod drive hydraulic system scram discharge volume header. All reactor control rods were already fully inserted. The loss of Division 1 RPS also caused the actuation of the Division 1 primary containment isolation logic. The Division 1 isolation valves in the balance-of-plant systems closed as designed. Both trains of the standby gas treatment system actuated. The loss of RSS no. 1 occurred during post-modification testing on relays at the local 230kV switchyard. The exact cause of the event is under investigation. This event is being reported in accordance with 10 CFR 50.72(b)(3)(iv)(A). The unit remains in cold shutdown with 1 source of offsite power and all 3 [EDG] available. The [NRC] Resident Inspector has been notified.

ENS 51701 +/-
Where
River Bend Louisiana (NRC Region 4)
Reporting

10 CFR 50.72(b)(3)(iv)(A), System Actuation
Time - Person (Reporting Time:+1.7 h0.0708 days <br />0.0101 weeks <br />0.00233 months <br />)
Opened:	Rob Melton 23:00 Jan 29, 2016
NRC Officer:	Dong Park
Last Updated:	Jan 29, 2016
51701 - NRC Website
v • d • e

v t e Emergency Notification System
River Bend with 10 CFR 50.72(b)(3)(iv)(A), System Actuation
WEEKMONTHYEAR2023-12-13T07:02:00 [Table view]
[ENS list for River Bend]

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