ML22307A004
| ML22307A004 | |
| Person / Time | |
|---|---|
| Site: | Cook  |
| Issue date: | 11/07/2022 |
| From: | American Electric Power Co |
| To: | Plant Licensing Branch III |
| Wall S | |
| References | |
| EPID L-2022-LRM-0089 | |
| Download: ML22307A004 (1) | |
Text
Amendment Request to Remove Neutron Flux from TS Table 3.3.3-1, Post Accident Monitoring Instrumentation November 7, 2022 1
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Background===
- At Cook Plant Unit 2, one required channel of neutron flux instrumentation is unable to meet Environmental Qualification requirements, but otherwise fully functional
- Vendor is winding down support for Gamma-Metrics instruments by end of 2024 and was not available for emergent support for repair/replacement during most recent U2 refueling outage
- Industry precedent exists for neutron flux variable to be considered as Category 3 instrumentation 2
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Background===
3
Proposed Change
- Remove Neutron Flux function from TS Table 3.3.3-1, Post Accident Monitoring Instrumentation
- Reclassify the Neutron Flux Post Accident Monitoring function to be RG 1.97 Category 3
- This would eliminate need for Environmental Qualification of Wide Range Neutron Flux instrumentation 4
Justification
- Function: Confirm initial Reactor Shutdown
- With harsh containment environment:
- adverse effects of steam or radiation are not immediate
- WR NIs operable for initial determination of reactor trip 5
Justification
- Function: Critical Safety Function Status Monitoring
- With harsh containment environment
- Other means of indication available to determine if imminent threat to critical safety function exists
- e.g., Fully Environmentally Qualified Core Exit Thermocouples, RCS Hot Leg and Cold Leg instruments address this function provided by Wide Range NIs 6
Industry Review
- At least five plants do not include Neutron Flux in their PAM TS
- Ginna,
- Byron/Braidwood,
- Comanche Peak and
- Farley 7