ML26033A039
| ML26033A039 | |
| Person / Time | |
|---|---|
| Site: | Palo Verde  |
| Issue date: | 02/02/2026 |
| From: | Arizona Public Service Co |
| To: | William Orders NRC/NRR/DORL/LPL4 |
| Orders, William | |
| References | |
| Download: ML26033A039 (0) | |
Text
Reactor Coolant System (RCS) Leak Detection Instrumentation License Amendment Request Pre-Submittal Meeting - February 10, 2026 Palo Verde Nuclear Generating Station
Agenda
- Background
- Case for Action
- Analytical Work
- Proposed Technical Specification/Bases Changes
- Schedule 2
=
Background===
3 Original PVNGS RCS leak detection Limiting Condition for Operation (LCO) included noble gas (gaseous) or particulate radiation monitoring and sump instruments Improvement in fuel performance reduced RCS gaseous concentrations during power operations limiting effectiveness of gaseous channel to detect RCS leakage In 1998, License Amendment 117 changed PVNGS LCO to require both gaseous and particulate channels be operable Containment sump instrumentation LCO requirements remained unchanged Gaseous channel remains in LCO consistent with RG 1.45 and NRC safety evaluations regarding GDC 4 and leak-before-break methodology for PVNGS
Case for Action 4
LCO 3.4.16 Required Action, Condition D, for a loss of all TS credited RCS leak detection instrumentation, is to enter LCO 3.0.3 immediately, which directs that Action shall be initiated within 1 hour1.157407e-5 days <br />2.777778e-4 hours <br />1.653439e-6 weeks <br />3.805e-7 months <br /> to place the unit in:
- a. MODE 3 within 7 hours8.101852e-5 days <br />0.00194 hours <br />1.157407e-5 weeks <br />2.6635e-6 months <br />;
- b. MODE 5 within 37 hours4.282407e-4 days <br />0.0103 hours <br />6.117725e-5 weeks <br />1.40785e-5 months <br /> Proposed change revises TS Section 3.4.16, RCS Leakage Detection Instrumentation, to modify the required actions such that 72 hours8.333333e-4 days <br />0.02 hours <br />1.190476e-4 weeks <br />2.7396e-5 months <br /> is provided to restore RCS leak detection instrumentation, in lieu of plant shutdown, provided alternative RCS leak detection actions are implemented
Case for Action 5
Goal is to avoid an unwarranted plant transient/shutdown Current requirement to enter LCO 3.0.3, on loss of all RCS leak detection instrumentation, disincentive to perform maintenance on instrumentation equipment at power, as a failure of related instrumentation would require immediate plant shutdown
Analytical Work 6
Change similar to Millstone License Amendment (ML082261529)
RCS Leak Detection Instrumentation is low risk
- Qualitative insights from PRA indicate LOCA events represent small contribution to Core Damage and Large Early Release frequencies
- Extending TS 3.4.16 Completion Time to 72 hours8.333333e-4 days <br />0.02 hours <br />1.190476e-4 weeks <br />2.7396e-5 months <br /> has very low safety impact on plant risk PVNGS Leak Before Break analyses support proposed completion times
Proposed Changes Addressed in LAR 7
Existing Condition C is redesignated as D and a new Condition C added that contains new Required Actions:
- 1. Analyze grab samples of the containment atmosphere OR
- 2. Perform SR 3.4.14.1 [i.e., RCS water inventory balance SR]
AND
- 3. Restore at least one RCS leakage detection monitor to OPERABLE status Completion Times for Required Actions C.1 and C.2 would be once per 12 hours1.388889e-4 days <br />0.00333 hours <br />1.984127e-5 weeks <br />4.566e-6 months <br /> Completion Time for Required Action C.3 would be 72 hours8.333333e-4 days <br />0.02 hours <br />1.190476e-4 weeks <br />2.7396e-5 months <br />
Proposed Changes Addressed in LAR 8
Conforming TS Bases Change - 3.4.16 Actions 9
Schedule 10 Pre-submittal meeting - February 10, 2026 Planned submittal - End of February 2026 Requested approval - 9 months (December 2026)
Will request 90-day implementation period following NRC approval