ML26009A027
| ML26009A027 | |
| Person / Time | |
|---|---|
| Site: | Surry  |
| Issue date: | 01/09/2026 |
| From: | Dominion Energy, Virginia Electric & Power Co (VEPCO) |
| To: | Klos L NRC/NRR/DORL/LPL2-1 |
| Klos, J | |
| References | |
| Download: ML26009A027 (0) | |
Text
Pre-Submittal Meeting for LAR for One Time Extension of Technical Specification TS 3.16 Action B.1.a.3 from 7 days to 14 days.
January 14, 2026 1
2 Agenda
Introductions
Background
Proposed Resolution Technical Justification Conclusions Schedule
SPS Units 1 and 2 have three emergency diesel generators (EDGs)
EDG 1 supplies power to Bus 1H EDG 2 supplies power to Bus 2H EDG 3 (Swing Diesel) provides power to Bus 1J or 2J Replacement of EDG 1 5 kV feeder cables to the 1H emergency bus is planned to occur during a Unit 1 outage, during which EDG 1 will be taken out of service The Subsequent License Renewal (SLR) Program determined replacement of EDG 1 5 KV cabling necessary based on an engineering study of age related cable degradation TS 3.16 Action B.1.a.3 requires that if an EDG is not returned to OPERABLE status in 7 days, the affected unit shall be brought to HOT SHUTDOWN within the next 6 hours6.944444e-5 days <br />0.00167 hours <br />9.920635e-6 weeks <br />2.283e-6 months <br /> and COLD SHUTDOWN within the next 30 hours3.472222e-4 days <br />0.00833 hours <br />4.960317e-5 weeks <br />1.1415e-5 months <br />
Background
January 14, 2026 3
The lowest risk plant operating state to perform the cable replacement is when Unit 1 is defueled Common equipment requirements and equipment credited in Surry design basis accident analysis place Unit 2 in a 7-day TS clock with EDG 1 out of service Charging and Auxiliary Feedwater cross ties are credited in the Surry design basis accident analysis, so Tech Specs for the EDGs still apply as long as either unit has fuel in the reactor Surry Unit 1 has two independent 4.16 kV emergency buses and associated switchgear. Buses 1H and 1J supply the Unit 1 safety-related loads. Each bus is sized to carry 100% of the emergency load Background Contd January 14, 2026 4
EDG 1 supplies power to Bus 1H and EDG 3 supplies power to Bus 1J when offsite power is lost. During normal operation, start-up, and shutdown, power to the emergency buses 1H and 1J are provided from the RSSTs (RSST C and RSST A, respectively)
Background Contd January 14, 2026 5
During a loss of offsite power (LOOP) scenario, with EDG 1 down for maintenance, there would be no backup for the 1H bus EDG 1 5 kV cable replacement is expected to take longer than 7 days to accomplish, thus requiring a Unit 2 shutdown while Unit 1 is in outage in accordance with the current requirement of TS 3.16 Action B.1.a.3 Background Contd January 14, 2026 6
Dominion Energy Virginia proposes a temporary TS change to grant a one-time AOT extension to facilitate EDG 1 5 kV cable replacement TS 3.16 Action B.1.a.3 would be changed from a 7-day AOT to a 14-day AOT for both Units 1 and 2 through the addition of a footnote to TS 3.16 Action B.1.a.3 Proposed Resolution January 14, 2026 7
Revised SPS Units 1 and 2 TS January 14, 2026 8
Technical Justification - Safety Margins and Defense-in-Depth
- Regulatory Guide 1.177, Section 2.2, Deterministic Engineering Considerations For TS CT changes, the effect on the final safety analysis report acceptance criteria should be assessed assuming the plant is in the conditions addressed by the proposed CT (i.e., the subject equipment is inoperable) and there are no additional failures.
& 3) will be available for Unit 2 to provide sufficient emergency power to design basis accident mitigation equipment January 14, 2026 9
Technical Justification - Risk Assessment Internal Events and Fire risk metrics for one-time TS change will be calculated in accordance with Regulatory Guide 1.177 Risk impact is within the threshold in accordance with Regulatory Guide 1.177 with effective compensatory measures Internal events and fire open finding dispositions will be provided in the LAR The EDG 1 will be out of service during the Unit 1 outage, therefore risk will be assessed for Unit 2 (online)
Remaining hazard groups (i.e., seismic, high winds, etc.) will be addressed qualitatively.
January 14, 2026 10
Technical Justification - Compensatory Measures FLEX AFW Pump will be pre-staged Fire watches will be in effect in areas risk significant for fire including:
o Unit 2 Emergency Switchgear and Relay Rooms o Unit 1 Switchgear Room o Unit 1 Turbine Building General Area Protect equipment - no maintenance will be performed on EDG 2, EDG 3, the turbine-driven AFW pump, the diesel-driven fire pump, Unit 2 power supplies, or SW strainers Operations will develop and follow a risk plan Surveillances will be completed on EDG 2 and EDG 3 prior to entering the AOT Weather conditions will be monitored prior to removing EDG 1 from service January 14, 2026 11
The proposed TS change would allow 5 kV cable replacement for EDG 1 be performed during the SPS Unit 1 outage with a one-time AOT extension With the risk of EDG 1 being out of service and a LOOP event occurring, our PRA modeling indicates safety factors within allowable limits for the 14-day AOT EDG 2 and EDG 3 will remain operable during the AOT to provide emergency power Risk impact is minimal Effective risk management actions have been established to address the most important risk scenarios Conclusion January 14, 2026 12
Facility Safety Review Committee (FSRC) is targeted for the middle of February LAR submittal is targeted for March 2026 NRC approval will be requested by March 2027 Schedule January 14, 2026 13
Questions?
January 14, 2026 14
15 Acronyms AOT Allowed Outage Time CT Completion Times EDG Emergency Diesel Generators FSRC Facility Safety Review Committee LAR License Amendment Request LCO Limiting Condition for Operation NRC Nuclear Regulatory Commission PRA Probabilistic Risk Assessment SPS Surry Power Station TS Technical Specifications RSST Reserve Station Service Transformer