NRC Receives Event Notification Involving Surry Power Reactor in Virginia
- Dec 13, 2019 7:08 am GMT
- 771 views
WASHINGTON, Dec. 12 -- The Nuclear Regulatory Commission issued the following event notification (No. 54437) involving the Surry power reactor in Virginia:
POTENTIAL TORNADO MISSILE VULNERABILITIES
"On December 11, 2019, at 1356 EST, it was concluded that certain safety-related equipment is vulnerable to design basis tornado missiles which could render the equipment inoperable and not able to perform its design function. This applies to the following Technical Specification equipment:
"1. Component cooling water piping for the 'A' spent fuel cooling water system heat exchanger. This heat exchanger is vulnerable to a horizontal missile traveling through the roll-up door, which would challenge operability of the Technical Specification required component cooling system equipment.
2. All three emergency service water pumps and their diesel fuel oil supply tank. The emergency service water pumps and diesel fuel oil tank are vulnerable to a horizontal missile penetrating the missile screens.
3. Certain component cooling water system pump discharge piping is vulnerable from a vertical missile penetrating the auxiliary building roof.
4. The Unit 1 Auxiliary Feedwater (AFW) system pumps and the pump suction and discharge piping are vulnerable to a missile traveling through the screens on the sides and roof of the main steam valve house. This vulnerability also exists for the Unit 2 AFW.
5. The Unit 2 Service Water (SW) supply valves to the river water make-up pump are vulnerable to a vertical missile traveling through the turbine building roof. A missile strike on the piping or valves could cause an unisolable leak or pipe break on this non-essential SW piping which could result in inability to maintain Technical Specification required intake canal inventory.
"These conditions are reportable in accordance with 10 CFR 50.72(b)(3)(ii)(B) as a condition that results in the nuclear power plant being in an unanalyzed condition that significantly degrades plant safety. There are no current operational challenges to either unit due to the tornado missile vulnerabilities.
"Identified SSCs [structures, systems, and components] were declared inoperable [at 1356] and NRC Enforcement Guidance Memorandum 15-002, Rev. 1, 'Enforcement Discretion for Tornado Generated Missile Protection Noncompliance,' was implemented. Initial compensatory measures were implemented, per the guidance of NRC Interim Staff Guidance DSS-ISG-2016-01 Appendix A, within the time allowed by the applicable Limiting Conditions for Operation (LCOs) and the associated systems were then declared operable, but nonconforming."
The NRC Resident Inspector has been notified.
Unit:   
RX Type:  W-3-LP, W-3-LP
NRC Notified By: ALAN BIALOWAS
HQ OPS Officer: ANDREW WAUGH
Emergency Class: NON EMERGENCY
10 CFR Section:
50.72(b)(3)(ii)(B) - UNANALYZED CONDITION
Event Number: 54437
Notification Date: 12/11/2019
Notification Time: 15:06 [ET]
Event Date: 12/11/2019
Event Time: 13:56 [EST]
Last Update Date: 12/11/2019
BRIAN BONSER (R2DO)