ML25330A022
| ML25330A022 | |
| Person / Time | |
|---|---|
| Site: | Vogtle  |
| Issue date: | 12/04/2025 |
| From: | John Lamb NRC/NRR/DORL/LPL2-1 |
| To: | Southern Nuclear Operating Co |
| References | |
| EPID L-2025-LRM-0144 | |
| Download: ML25330A022 (0) | |
Text
Proposed Vogtle Electric Generating Plant Units 3 & 4 License Amendment Request Revise Technical Specifications for Engineered Safety Feature Actuation System (ESFAS) Manual Initiation and Diverse Actuation System (DAS) Manual Controls December 4, 2025
Agenda Description Technical Evaluation Regulatory Evaluation Schedule Discussion / Feedback
ESFAS Manual Initiation and DAS Manual Controls Applicabilities DESCRIPTION Example 1 of Changes Based on Technical Specification Consistency TS 3.3.9, ESFAS Manual Initiation Function 1, Safeguards Actuation - Manual Initiation, Applicability - Modes 1-5.
Change to remove Mode 5 Applicability UFSAR Subsection 7.3.1.1 & TS 3.3.8 Bases - Safeguards Actuation (S) Signal, initiated by:
o Containment Pressure High TS 3.3.8 Function 2, Modes 1-4 o Pressurizer Pressure Low TS 3.3.8 Function 5, Modes 1-3 o Reactor Coolant System (RCS) Cold Leg Temperature Low-2 - TS 3.3.8 Function 1 Modes 1-3 o Steam Line Pressure Low TS 3.3.8 Function 24, Modes 1-3 3
ESFAS Manual Initiation and DAS Manual Controls Applicabilities DESCRIPTION (continued)
Example 1 (continued) - TS 3.3.9, ESFAS Manual Initiation Bases - Manual initiation is required in MODE 5 to support system level initiation.
Not required by any safety analysis Systems initiated by S signal o Containment Isolation - TS 3.3.9 Function 3, Modes 1-4 o Reactor Trip - TS 3.3.1 all Functions, Modes 1-2 o Feedwater Isolation - TS 3.3.9 Function 5 Modes 1-4 o CMT Actuation - TS 3.3.9 Function 2, Modes 1-5 (M5 with RCS not Vented) o RCP Trip - TS 3.5.9, RCP Breakers Modes 1-5 (M5 with RCS not Vented) o Bases indicate allows passive injection of borated water into the RCS.
o CMT Actuation also trips RCP; thus, S signal Mode 5 RCP trip not necessary 4
ESFAS Manual Initiation and DAS Manual Controls Applicabilities DESCRIPTION (continued)
Example 2 of Changes Based on Technical Specification Consistency TS 3.3.9, ESFAS Manual Initiation Function 9, Passive Residual Heat Removal (PRHR) Heat Exchanger (HX) Actuation
- Manual Initiation, Applicability - Modes 1,2,3,4,5(c) -
- (c) MODE 5 with the RCS pressure boundary intact.
Change footnote (c) to revise Mode 5 Applicability consistent with TS 3.5.5 TS 3.5.5 - PRHR HX - Shutdown, RCS Intact - Applicabilities
- MODE 4 with the RCS cooling provided by the Normal Residual Heat Removal System (RNS).
- MODE 5 with the RCS pressure boundary intact and pressurizer level 20%.
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ESFAS Manual Initiation and DAS Manual Controls Applicabilities DESCRIPTION (continued)
Example 2 (continued)
TS 3.3.9, ESFAS Manual Initiation Function 9, Passive Residual Heat Removal (PRHR) Heat Exchanger Actuation -
Manual Initiation, Applicability - Modes 1-5 (M5 with the RCS pressure boundary intact.)
Change Mode 5 Applicability Notes consistent with TS 3.5.5
- New note - Not required during RCS vacuum fill operations.
TS 3.5.5 - Applicabilities include a Note
- PRHR HX is not required to be OPERABLE in MODE 5 during RCS vacuum fill operations.
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ESFAS Manual Initiation and DAS Manual Controls Applicabilities DESCRIPTION (continued)
Example 3 of Changes Based on Technical Specification Consistency TS 3.3.19, DAS Manual Controls Function 2, PRHR HX control and In-Containment Refueling Water Storage Tank (IRWST) gutter control valves Applicability - Mode 5 with Reactor Coolant System (RCS) pressure boundary intact Change Mode 5 Applicability to match TS 3.5.5 Applicability and add new Note TS 3.5.5, PRHR HX - Shutdown, RCS Intact Applicability - Mode 5 with Reactor Coolant System (RCS) pressure boundary intact and pressurizer level 20%.
Note - PRHR HX is not required to be OPERABLE in MODE 5 during RCS vacuum fill operations.
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ESFAS Manual Initiation and DAS Manual Controls Applicabilities DESCRIPTION (continued)
Example 4 of Changes Based on Technical Specification Consistency TS 3.3.19, DAS Manual Controls Functions 4, 5, 6, Automatic Depressurization System (ADS) Stage 1, 2, 3 Actuation Applicability - Modes 1, 2, 3, 4,5(a)
- (a) with the RCS pressure boundary intact TS 3.3.9, ADS Stage 1, 2, 3 Actuation Applicability - Modes 1, 2, 3, 4,5(d)
- (d) with RCS not VENTED.
Change Mode 5 Applicabilities to match TS 3.3.9 TS 3.3.9 Bases - In MODE 5 with the RCS VENTED and in MODE 6 with upper internals in place, LCO 3.4.13, ADS - Shutdown, RCS Open, requires the ADS Stages 1, 2, and 3 valves to be open. Thus, Manual actuation is not required.
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ESFAS Manual Initiation and DAS Manual Controls Applicabilities DESCRIPTION (continued)
Example 5 of Changes Based on Technical Specification Consistency TS 3.3.19, DAS Manual Controls Function 11, Selected containment isolation valves Applicability - Modes 1, 2, 3, 4, 5, and 6 Remove Modes 5 and 6 Applicabilities to match TS 3.6.3 and TS 3.3.9 Function 3 TS 3.6.3, Containment Isolation Valves Applicability - Modes 1, 2, 3, 4 TSB 3.6.3, In MODES 5 and 6, the probability and consequences of these events are reduced due to the pressure and temperature limitations of these MODES.
TS 3.3.9, Function 3, Containment Isolation - Manual Initiation Applicability - Modes 1, 2, 3, 4 TS 3.6.7 containment closure accomplished without DAS.
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ESFAS Manual Initiation and DAS Manual Controls Applicabilities DESCRIPTION (continued)
Example 5 (continued)
TS 3.6.7, Containment Penetrations Applicability - Modes 5 and 6 TSB 3.6.7, Further, accident analyses have shown that containment closure capability is not required to meet offsite dose requirements.
TSB 3.6.7, In MODES 5 and 6, there is no potential for steam release into the containment immediately following an accident.
TSB 3.6.7, To support RCS heat removal, containment closure is required to limit the loss of the cooling water inventory from containment (Ref. 1).
TSB 3.6.7, Reference 1, FSAR subsection 19E.2.6.2.
UFSAR subsection 19E.2.6.2 - To limit the magnitude of cooling water inventory losses and because local manual action may be required to achieve containment closure, the containment hatches, air locks, and penetrations must be closed prior to steaming into containment.
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ESFAS Manual Initiation and DAS Manual Controls Applicabilities DESCRIPTION (continued)
Example of Changes with Other Basis - Editorial TS 3.3.9, Engineered Safeguards Actuation System Instrumentation - Manual Initiation Function 8, Passive Containment Cooling Actuation - Manual Initiation Applicability - Mode 5 (f) With decay heat > 7.0 MWt.
Change to match TS 3.6.6. Mode 5 With the reactor decay heat > 7.0 MWt.
Function 9, Passive Residual Heat Removal Heat Exchanger Actuation - Manual Initiation Required Channels - 2 Switches Change to match other listing of Required Channels - 2 switches 11
ESFAS Manual Initiation and DAS Manual Controls Applicabilities TECHNICAL EVALUATION For consistency changes (TS 3.3.9, Function 6 & TS 3.3.19, Functions 2, 4, 5, 6, & 11),
if the corresponding systems and components are not required to be OPERABLE, These manual controls should not be required by the Technical Specifications; and These diverse manual controls should not be required by the Technical Specifications.
For other basis changes (TS 3.3.9, Function 1), if the manual controls are not credited or otherwise depended upon, manual controls should not be required by the Technical Specifications.
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ESFAS Manual Initiation and DAS Manual Controls Applicabilities REGULATORY EVALUATION
- Revised TS Applicabilities continue to support the required operability of assumed system level safety function required to satisfy 50.36.
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ESFAS Manual Initiation and DAS Manual Controls Applicabilities Bases Changes provided for information only.
Related Bases Changes Associated with each Applicability Change Bases also changed to identify the selected containment isolation valves associated with TS 3.3.19, Function 11 consistent with UFSAR Table 17.4-1.
The selected containment isolation valves include:
- CVS-PL-V045, CVS-PL-V047,
- VFS-PL-V003, VFS-PL-V004, VFS-PL-V009, VFS-PL-V010,
- WLS-PL-V055, and WLS-PL-V057.
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ESFAS Manual Initiation and DAS Manual Controls Applicabilities Schedule
- Target submittal 4Q2025
- Outage related No
- Target approval 3Q2026 15
ESFAS Manual Initiation and DAS Manual Controls Applicabilities Discussion / Feedback 16