06:50 Apr 11, 2018
Condition That Could Impair Function of Control Building Ac System
At time 0150 CDT on April 11, 2018, a condition was identified that could impair the ability of the Control Building Air Conditioning System to perform its design function.
Engineering determined that the time delay relays HVKA11-80YB or HVKA11-80YD (Division II chilled water LOW FLOW relays) could fail in a manner that challenges the design safety function of the Control Building Chilled Water System during a Loss of Offsite Power (LOP) Event. A failure of the time delay relay HVKA11-80YB or HVKA11-80YD (Division II chilled water LOW FLOW relays) to provide the time delay function would cause both the Division I and Division II HVK chilled water pumps to start after a LOP, which in turn could hinder the auto start of either Division I or Division II chillers.
Currently the Chilled Water System is otherwise operating as designed. All operator actions are in place to ensure the plant meets all required designed safety system functions. Work is currently underway to correct this design vulnerability.The NRC Resident Inspector has been notified of this condition.
|River Bend |
Louisiana (NRC Region 4)
|10 CFR 50.72(b)(3)(ii)(B), Unanalyzed Condition|
10 CFR 50.72(b)(3)(v)(D), Loss of Safety Function - Mitigate the Consequences of an Accident
|Time - Person (Reporting Time:+3.4 h0.142 days <br />0.0202 weeks <br />0.00466 months <br />)|
10:14 Apr 11, 2018
|NRC Officer:||Donald Norwood|
|Last Updated:||Apr 11, 2018|
|53324 - NRC Website|