ML16198A001
| ML16198A001 | |
| Person / Time | |
|---|---|
| Site: | Calvert Cliffs  (DPR-053, DPR-069) |
| Issue date: | 07/18/2016 |
| From: | Kimberly Green Calvert Cliffs |
| To: | Richard Guzman Plant Licensing Branch 1 |
| Guzman R | |
| References | |
| Download: ML16198A001 (14) | |
Text
Calvert Cliffs GSI-191 Program Zone of Influence, Debris Size Distribution, Option 2b Closure Approach, and LAR Exemption Request July 18, 2016
Agenda
- Introductions
- Objectives for Meeting
- Option 2b Simplified Risk-Informed Closure Plan
- Strainer Performance Criteria
- LOCA Frequency Allocation
- Zone of Influence and Debris Size Distribution
- Staff Questions & Concerns
- Schedule for Future Periodic Meetings Calvert Cliffs Chemical Effects Testing & Option 2b Refined Closure Plan 1
CCNPP Attendees
- Doug Lauver-Senior Engineering Manager
- Andre Drake - Lead Responsible Engineer GSI-191
- Ken Greene - Licensing Engineer
- Craig Sellers - Project Manager GSI-191
- Eric Federline - Project Support Calvert Cliffs Chemical Effects Testing & Option 2b Refined Closure Plan 2
Objectives of this Meeting
- Discussion of Calvert Cliffs Simplified Risk-Informed Approach
- Strainer Performance Criteria
- LOCA Frequency Allocation
- Discussion of Revised ZOIs and Debris Size Distributions
- Capture Staff Issues and Concerns
- Discuss Next Steps Calvert Cliffs Chemical Effects Testing & Option 2b Refined Closure Plan 3
Simplified Risk-Informed Approach Strainer Performance Criteria
- Strainer Failure Modes:
- Pump NPSH
- Structural Failure
- Deaeration - Limiting Failure Mode
- Strainer Performance Criteria
- 1) Mass of Fine Fiber Debris
- 2) Mass of Particulate Debris
- 3) Mass of WCAP-16530 Chemical Precipitate Debris*
- Provided sufficient fiber to cover strainer 1/16
- Preliminary Results
- 19 of 62 Welds 30 ID Exceed Criteria of Fiber and/or Precipitate Mass
- 7 of 19 Exceed only Precipitate Criterion
- 2 of 72 12 ID Welds Exceed Precipitate Criterion
- Equivalent Uniform Fiber Bed Thickness ~1/23 and 1/28
- Insufficient Debris Bed to Capture Precipitate
- No Threat to Strainer Performance Calvert Cliffs Chemical Effects Testing & Option 2b Refined Closure Plan 4
Simplified Risk-Informed Approach (continued)
Calculate CDF - Preliminary Results
- Use Conservative Approach
- Smallest break that threatens strainer performance - 30 DEGB
- NUREG-1829 LOCA Frequencies
- Equally Apportion LOCA Frequency Across RCS Welds Degradation mechanisms are Design and Construction for all 62 RCS welds PWSCC also on 8 RCS welds
- NUREG-1829 LOCA Frequencies
- 62 Butt Welds 30
- 19 Welds 30 Threaten Strainer Performance
- 3 are DM Welds - Double Counted Calvert Cliffs Chemical Effects Testing & Option 2b Refined Closure Plan 5
- Log-Linear Interpolation LOCA Category Break Size (in.)
Geometric Mean1 Arithmetic Mean2 1
0.5 1.90E-03 1.00E-02 2
1.625 4.20E-04 3.00E-03 3
3 1.60E-05 7.30E-05 4
7 1.60E-06 9.40E-06 5
14 2.00E-07 2.40E-06 6
31 2.90E-08 1.50E-06 Notes:
[1] Taken from Table 7-19 of NUREG-1829
[2] Taken from Table 7-13 of NUREG-1829 LOCA Category Break Size
(>in.)
Geometric Mean Arithmetic Mean 1
0.5 1.90E-03 1.00E-02 2
1.625 4.20E-04 3.00E-03 3
3 1.60E-05 7.30E-05 4
7 1.60E-06 9.40E-06 5
14 2.00E-07 2.40E-06 5.5 30 3.25E-08 1.54E-06 6
31 2.90E-08 1.50E-06
Simplified Risk-Informed Approach (continued)
License Amendment Request
- Calvert Cliffs Planning to Request Exemption from 10CFR50.46(a)(1.)
- Similar to South Texas Project
- Calvert Cliffs not licensed to 10CFR50 Appendix A General Design Criteria
- Do not need exemption from GDC Calvert Cliffs Chemical Effects Testing & Option 2b Refined Closure Plan 6
Zone of Influence & Debris Size Distribution
- CCNPP Submitted Supplemental Response to GL 2004-02 on June 8, 2016
- Addressed Revised ZOI and Debris Size Distributions for:
- NUKON & Thermal Wrap Blanket Insulation
- Mineral Wool Insulation in Stainless Steel Cassettes
- Generic Fiberglass Insulation
- Lead Wool Shielding Blankets
- Based on data accepted at other plants Calvert Cliffs Chemical Effects Testing & Option 2b Refined Closure Plan 7
ZOI & Debris Size Distribution - NUKON & Thermal Wrap
- 3 Zones of Influence, 4 Debris Size Distribution
- ENERCON Approach using Insulation Centroid
- Based on NEI 04-07 Safety Evaluation Guidance
- Accepted at Other Plants Calvert Cliffs Chemical Effects Testing & Option 2b Refined Closure Plan 8
Debris Size Average (Centroid) Distance from Break Location to Target 0D - 4D ZOI 4D - 15D ZOI 15D - 17D ZOI Fines Fraction (Ffines)
Ffines = 0.2 Ffines = -0.01364 x C + 0.2546 Ffines = -0.025 x C + 0.425 Small Pieces Fraction (Fsmalls)
Fsmalls = 0.8 Fsmalls = -0.0682 x C + 1.0724 Fsmalls = -0.025 x C + 0.425 Large Pieces Fraction (Flarge)
Flarge = 0 Flarge = 0.0393 x C - 0.157 Flarge = -0.215 x C + 3.655 Intact Pieces Fraction (Fintact)
Fintact = 0 Fintact = 0.0425 x C - 0.170 Fintact = 0.265 x C - 3.505
ZOI & Debris Size Distribution - Mineral Wool
- Mineral Wool at CCNPP is Transco Stainless Steel Cassette Design
- 0.024 SS Sheath with Slotted End Panels
- Installed in Plant Tested at CEESI, Tests 22-1 to 22-3
- Tested cassettes contained metal foil and produced none or very little transportable debris.
- The contained material contributes no strength to the cassettes.
- Therefore, the destruction pressure for the Transco mineral wool cassettes and RMI cassettes are considered equal.
- To account for the difference in filler material, the ZOI for the mineral wool cassettes will be conservatively increased by a factor of 2 from 2.0D to 4.0D.
- The debris size for the mineral wool will be conservatively assumed to be 100% fine fibers.
Calvert Cliffs Chemical Effects Testing & Option 2b Refined Closure Plan 9
ZOI & Debris Size Distribution - Generic Fiberglass
- Anti-Sweat Insulation on Unit 1 CCW piping
- Molded of heavy density resin bonded inorganic glass fibers
- Jacketed with 0.010 riveted stainless steel
- Bulk density generally greater than Nukon and Thermal Wrap.
- 3.5 to 5.5 lbm/ft3 verses 2.4 lbm/ft3
- The mass percentage of generic fiberglass relative to total fibrous debris load is <20% for the bounding break at Calvert Cliffs.
- Calvert Cliffs assumes that the ZOI and debris size distribution for generic fiberglass is that used for Nukon and Thermal Wrap based on the insulation density.
Calvert Cliffs Chemical Effects Testing & Option 2b Refined Closure Plan 10
ZOI & Debris Size Distribution - Lead Wool Shielding Blankets
- Two Zones of Influence, 3 Debris Size Distribution
- ZOI based on CESSI Air Jet Impact Tests
- Typical Installed Configuration Calvert Cliffs Chemical Effects Testing & Option 2b Refined Closure Plan 11 Debris Type Size Size Distribution 2.1D ZOI 2.1D - 5.4D ZOI Lead Blanket Cover Layers Closest to Pipe Break (Open Back Configuration)
Fines 20%
0%
Small Pieces 80%
0%
Large/Intact Pieces 0%
100%
Remaining Lead Blanket Cover Layers (Open Back Configuration)
Fines 0%
0%
Small Pieces 0%
0%
Large/Intact Pieces 100%
100%
Wrapped Lead Blanket Cover Layers (Strong Back Configuration)
Fines 0%
0%
Small Pieces 0%
0%
Large/Intact Pieces 100%
100%
Questions/Concerns
- Jointly Review Issues, Questions, and Concerns for Future Communication Calvert Cliffs Chemical Effects Testing & Option 2b Refined Closure Plan 12
Next Steps
- Finalize Update of Deterministic Calculations
- Present Formal Risk-Informed GSI-191 Analysis and Results
- Desire Next Meeting - 4Q 2016 Calvert Cliffs Chemical Effects Testing & Option 2b Refined Closure Plan 13