ML100471104
| ML100471104 | |
| Person / Time | |
|---|---|
| Site: | Diablo Canyon  |
| Issue date: | 01/22/2010 |
| From: | Lin A Pacific Gas & Electric Co |
| To: | Office of Nuclear Reactor Regulation |
| Lyon W, DSSA/SRXB, 415-2897 | |
| Shared Package | |
| ML100480102 | List: |
| References | |
| GL-08-001 | |
| Download: ML100471104 (8) | |
Text
Diablo Canyon GL 2008-01 Void Intrusion Modifications Anderson Lin Diablo Canyon Power Plant (805) 545-4286 Axle@pge.com NEI Workshop January 22, 2010
Mitigation Strategy 1.
Pump Suction : Remove Voids Away From the Active ECCS Flow Paths 2.
Pump Discharge: Enhance / Increase Isolation Barriers 3.
System Dynamic Venting: Coming Out of Outage 4.
System Monitoring: Symptom Based Monitoring
1-A : CCP Suction Modification: Void Header
- Collect Voids Away From the Active Flowpath Seal Water Hx VCT To SIPs Suction 6
From RCP Seal Return To CCP #3 8: Fr = 0.18 or 0.26 4: Fr = 0.98 or 1.38 8
From RHRP
CCP Suction Void Header UT Port
1-B: RHR Pump Suction a) Air Ingested During RCS Mid-Loop RHR Hx RWST RCS Hot Leg Fr ~ 0.7
1-B: RHR Pump Suction b) Air Transport During Pump Test RHR Hx RWST RCS Hot Leg Miniflow Fr ~ 15 Hx Tube Fr ~ 1.2 RHR Suction Fr ~ 0.4
1-B: RHR Pump Suction c) Collect Void Away From Active Flowpath RHR Hx RWST RCS Hot Leg Miniflow Fr ~ 15 Hx Tube Fr ~ 1.2 RHR Suction Fr ~ 0.4
- 2. Discharge Piping - Enhance Isolation From Accumulators & Replace Check Valves A.
Replace 10 AOVs in the test line on the accumulator side with Anchor Darling Manual Valves B.
Replace all 4 SI Check Valves C.
Replace another 9 AOVs, and install 37 Manual Isolation Valves for Test Optimization Modifications and To Add Barriers to Enhancement Isolation (6 and To Add Barriers to Enhancement Isolation (6 isolation valves in between Accumulator and ECCS Lines in most cases)
Test Station