ML15321A370

GSI-191 Program Strainer Head Loss Testing and Option 2b Closure Approach

ML15321A370
Person / Time
Site:	Calvert Cliffs
Issue date:	12/01/2015
From:	Exelon Generation Co
To:	Office of Nuclear Reactor Regulation
References
Download: ML15321A370 (21)

Text

Calvert Cliffs GSI-191 Program Strainer Head Loss Testing and Option 2b Closure Approach December 2015

Agenda

• Introductions

• Objectives for Meeting

• Discussion of Strainer Chemical Effects Head Loss Testing

• Discussion of Option 2b Simplified Risk-Informed Closure Plan

• Status of Calvert Cliffs Work

• Staff Questions & Concerns

• Schedule for Future Periodic Meetings 1 Calvert Cliffs Chemical Effects Testing & Option 2b Refined Closure Plan

CCNPP Attendees

• Mike Gahan - Engineering Manager

• Andre Drake - Lead Responsible Engineer GSI-191

• Jim Landale - Lead PRA Engineer

• Ken Greene - Licensing Engineer

• Craig Sellers - Project Manager GSI-191

• Steve Kinsey - Strainer Chemical Effects Head Loss Testing

• Eric Federline - Project Support & Testing

• Patrick Romine - Project Support & Testing 2 Calvert Cliffs Chemical Effects Testing & Option 2b Refined Closure Plan

Objectives of this Meeting

• Discussion of Strainer Chemical Effects Head Loss Testing

• Presentation of Calvert Cliffs Simplified Risk-Informed Approach

• Capture Staff Issues and Concerns

• Discuss Next Steps 3 Calvert Cliffs Chemical Effects Testing & Option 2b Refined Closure Plan

Strainer Head Loss Testing

• CCNPP Conducted 7 Strainer Head Loss Tests in 2010

- Performed in CCI Multi-Function Test Facility (MFTF) in Switzerland

- Debris Preparation in Accordance with CCI Protocols

• Fiber disintegrated into Fines using high pressure jet

- NRC observed CCI debris preparation protocols

- Debris introduced in 5 batches

• Each batch 20% of particulate followed by 20% of fiber

• First batch included 100% of Marinite

- Tests included WCAP-16530 Chemical Precipitate Surrogate

• WCAP surrogate prepared in accordance with WCAP guidance

• WCAP surrogate introduced via metering pump

- Flow Rate

• 5000 gpm equivalent prior to chemical addition (Design)

• 2400 gpm equivalent for chemical addition

- 820 gpm HPSI, 600 to 1000 gpm per EOP-5

- 1580 gpm CS (One CS Pump)

• One CS pump secured at containment pressure < 2.8 psig

• Containment Response calculation shows sump temperature > 150°F at 2.8 psig

• Sodium Aluminum Silicate does not precipitate until sump temperature < 140°F

• Optional flow sweep prior to test termination 4 Calvert Cliffs Chemical Effects Testing & Option 2b Refined Closure Plan

Strainer Head Loss Testing (continued)

• Test #1 Included Fine and Small Fibrous Debris

- Maximum Head Loss 1.75 inches of water

- Non-Uniform Debris Deposition

Conclusion:

Testing with Small Pieces is Non-Conservative

- Results of Test #1 were Rejected as Non-Conservative 5 Calvert Cliffs Chemical Effects Testing & Option 2b Refined Closure Plan

Strainer Head Loss Testing (continued)

• Remaining Tests Used Only Fine Fibrous Debris

- Full load of particulates and precipitates

- Test for Success Campaign

- Break-throughs experienced during each test 6 Calvert Cliffs Chemical Effects Testing & Option 2b Refined Closure Plan

Strainer Head Loss Testing (continued)

• Test 6 Rejection

- Test 6 was rejected in 2010

- Documented basis for rejection was limited

- Email archives from period searched

• Significant discussion of improper agitation observed

• Use of the hand held drill was lifting the debris within the Test Bed and creating a new profile that was considered not to be consistent with previous and subsequent testing.

• A formal evaluation of the test was performed and additional guidance on agitation control was prepared.

• After communication with the CCNPP project team the results of Test 6 were rejected.

• This rejection was performed before proceeding with Test 7.

- This has been documented and added to test files at CCNPP 7 Calvert Cliffs Chemical Effects Testing & Option 2b Refined Closure Plan

Strainer Head Loss Testing (continued)

• Test Debris Types & Equivalent Quantities

• Test Head Loss Results (ft-water)

Test Test Debris HL CS HL Total HL Debris Type 3 4 5 7 2 0.05 0.28 0.33 3 3.165 0.28 3.445 Nukon 167 ft3 36 ft3 88 ft3 61.5 ft3 4 0.599 0.28 0.879 Thermal Wrap 154 ft3 227 ft3 227 ft3 227 ft3 5 1.211 0.28 1.491 Temp-Mat 3.61 ft3 3.61 ft3 3.61 ft3 3.61 ft3 7 0.656 0.28 0.936 Generic LDFG 44.5 ft3 4.1 ft3 4.1 ft3 0 ft3 Mineral Wool 0 ft3 0 ft3 0 ft3 0 ft3 Lead Blanket Cover 0 ft3 0 ft3 0 ft2 564.5 ft2

• Maximum Allowable Strainer Head Loss Epoxy Particulate 2 ft3 1.5 ft3 2 ft3 1.5 ft3 - Currently Under Development IOZ Particulate 5.9 ft3 4.8 ft3 5.9 ft3 4.8 ft3 - Limiting Failure Mode is Deaeration Unqual Part 2 ft3 1.3 ft3 2 ft3 1.3 ft3

- Will range 1.75 to 2.5 ft-water Latent Particulate 1.275 ft3 1.275 ft3 1.275 ft3 1.275 ft3 Marinite 0.2 ft3 0.2 ft3 0.2 ft3 0.2 ft3 NaAlSi3O8 59.48 lbs 47.70 lbs 54.1 lbs 56.8 lbs

• Test 5 Test with Highest Acceptable Head Loss 8 Calvert Cliffs Chemical Effects Testing & Option 2b Refined Closure Plan

Strainer Head Loss Correlation Demonstrates Head Loss Proportional to Mass of Fine Fiber

• Plot of Head Loss -vs- Fiber Mass produces well correlated curve fit

• Plot includes clean strainer head loss

• Empirical Correlation based on Calvert Cliffs Prototypical Strainer Head Loss Testing Head Loss Data - Test Data + Clean Screen 2

y = 0.4444ln(x) + 1.1646 R² = 0.9949 Fine Fiber Mass (kg) 1.5 1

0.5 Total HL Log. (Total HL) 0 0 0.5 1 1.5 2 2.5 3 3.5 4 Head Loss (ft-water) 9 Calvert Cliffs Chemical Effects Testing & Option 2b Refined Closure Plan

Simplified Risk-Informed Approach Define Threshold Break Size

• Identify Applicable Strainer Chemical Effects Head Loss Test

- WCAP-16530 Chemical Surrogates

• Identify Smallest Break(s) that Generate Equivalent Quantity of Fine Fibrous Debris as used in Applicable and Acceptable Head Loss Test

- Also key criteria

• Quantity of Particulate for Each Break

• Quantity of WCAP-16530 Precipitate for Each Break

• Breaks That Produce Less Debris Than Tested are Acceptable Through Deterministic Analysis

• Breaks That Produce More Debris Than Tested are Addressed Probabilistically (Risk-Informed)

- The ID of the smallest break that produces more debris than tested is defined as the Threshold Break Size 10 Calvert Cliffs Chemical Effects Testing & Option 2b Refined Closure Plan

Simplified Risk-Informed Approach Calculate CDF & LERF

• CDF and LERF are taken from the Calvert Cliffs PRA Model of Record.

• CDF Determined from LOCA Frequency for Threshold Break Size

- Apportion LOCA Frequency Across Welds Threshold Break Size

- Interpolate within NUREG-1829 Intervals as needed for Break Size

- CDF = Apportioned LOCA Frequency for Breaks that produce more debris than tested

- Sensitivities on interpolation and LOCA Frequency Aggregation Methods

• LERF approach is to obtain a CDF multiplier from the Calvert Cliffs LERF model that is bounded by a worst case accident sequence for the Threshold Break Size for non SBO conditions.

• Compare CDF, CDF, LERF, and LERF results against Reg Guide 1.174 criteria for Region III.

• Verify other requirements (safety margin, defense in depth) of Reg Guide 1.174 are met.

11 Calvert Cliffs Chemical Effects Testing & Option 2b Refined Closure Plan

Simplified Risk-Informed Approach (Continued)

Deterministic Analysis

• Breaks Acceptable Through Deterministic Analysis

- Bounding Analyses

• NEI 04-07

- Limiting Single Failure

• All HPSI pumps running

• Credit for Operator Actions in EOPs

- Secure one CS pump

• Failure of LPSI pump to trip being resolved through plant modification

- Safety Related Calculations

• Calvert Cliffs GSI-191 calculations prepared in accordance with Appendix B QA program 12 Calvert Cliffs Chemical Effects Testing & Option 2b Refined Closure Plan

Simplified Risk-Informed Approach (continued)

Identify Applicable Head Loss Test

• Test 5 and DEGB @ ISI 30-RC-11A-6 (Crossover Leg at RCP Suction Elbow)

- Test 5 used equivalent of 825.7 lbm Fiber Fines

- Use 800 lbm Acceptance Criterion

- DEGB @ ISI 30-RC-11A-6 generated 797.8 lbm Fiber Fines Material Lead Thermal Generic Mineral Epoxy Alkyd Latent Nukon Temp-Mat Blanket IOZ Part. Marinite NaAlSi3O8 Wrap LDFG Wool Part. Part. Part.

Cover 210.9# 543.2# 42.9# 28.6# 2 ft3 5.9 ft3 2 ft3 Test 5 0# 0# 3 1.275 ft3 0 ft3 54.1 lbs E-Glass 825.7 lbm 9.9 ft ISI 309.6# 249.8# 30.2# 179.9# 1.21 ft3 2.22 ft3 1.74 ft3 22.58# 0# 1.275 ft3 0.12 ft3 65.8 lbs 30-RC-11A-6 E-Glass 769.5 lbm 5.17 ft3

• Test 5 had

- 56 lbm more E-Glass fiber fines

- 22.58 lbm less mineral wool

• Mineral wool 2.8% of fine fiber quantity

• CHLE investigatory tests showed no notable head loss impact from mineral wool

- 73% more failed coatings & latent particulate

- 0.12 ft3 less Marinite

- 82% of NaAlSi3O8 precipitate

• All tests experienced debris bed break-throughs relieving P before 100% WCAP-16530 surrogate precipitates introduced 13 Calvert Cliffs Chemical Effects Testing & Option 2b Refined Closure Plan

Simplified Risk-Informed Approach (continued)

Identify Small Breaks that Produce Sufficient Debris

• Risk-Informed Debris Generation Calculation Results

- Breaks Analyzed at 437 Circumferential Welds

- Longitudinal Welds Currently Being Analyzed

- ISI 30-RC-11A-6 is break #25 below DEGB Fiber Fines Mass for 70 Largest Breaks 1600 Loop 11 Hot Leg DEGB at Base of SG 1400 1200 Loop 12 Mass od Fiber Fines (lbm) 1000 RCS Loop DEGBs in RCP Bays 800 600 RCS Loop DEGBs at Rx Nozzles 400 Smaller 200 Breaks 0

0 10 20 30 40 50 60 70 Break Number Fiber Mass Acceptance Criterion 14 Calvert Cliffs Chemical Effects Testing & Option 2b Refined Closure Plan

Simplified Risk-Informed Approach (continued)

Calculate CDF - Preliminary Results

• Use Conservative Approach

• Linear Interpolation

- Smallest break that threatens strainer LOCA Break Size Geometric Arithmetic Category (>in.) Mean Mean performance - 30 DEGB 1 0.5 1.90E-03 1.00E-02

- NUREG-1829 LOCA Frequencies 2 1.5 4.20E-04 3.00E-03

- Equally Apportion LOCA Frequency Across 3 3 1.60E-05 7.30E-05 4 6.75 1.60E-06 9.40E-06 RCS Welds 5 14 2.00E-07 2.40E-06

• Degradation mechanisms are Design and Construction for all 126 RCS welds 5.5 30 4.37E-08 1.58E-06

• PWSCC also on 8 RCS welds 6 31.5 2.90E-08 1.50E-06 LOCA Break Size Geometric Arithmetic

1. Welds #Failed CDF GM CDF AM Category (in.) Mean1 Mean2 126 24 8.32E-09 3.00E-07 1 0.5 1.90E-03 1.00E-02 2 1.5 4.20E-04 3.00E-03

• Log-Log Interpolation 3 3 1.60E-05 7.30E-05 LOCA Break Size Geometric Arithmetic 4 6.75 1.60E-06 9.40E-06 Category (>in.) Mean Mean 5 14 2.00E-07 2.40E-06 1 0.5 1.90E-03 1.00E-02 6 31.5 2.90E-08 1.50E-06 2 1.5 4.20E-04 3.00E-03 Notes:

3 3 1.60E-05 7.30E-05

[1] Taken from Table 7-19 of NUREG-1829 4 6.75 1.60E-06 9.40E-06

[2] Taken from Table 7-13 of NUREG-1829 5 14 2.00E-07 2.40E-06

- 126 Welds 30 5.5 30 3.93E-08 1.55E-06 6 31.5 2.90E-08 1.50E-06

- 24 Welds 30 Threaten Strainer # Welds #Failed CDF GM CDF AM Performance 126 24 7.48E-09 2.96E-07 15 Calvert Cliffs Chemical Effects Testing & Option 2b Refined Closure Plan

Differences STP - VOGTLE - CCNPP

• Physical Item STP VOGTLE CCNPP NSSS Westinghouse Westinghouse CE Circumferential &

RCS Piping Welds Circumferential Welds Circumferential Welds Longitudinal Welds RCS Piping ID 31 31 42 & 30 ECCS Trains 3 2 2 Strainer Config. 3 combined 4 separate 1 combined Strainer Design PCI Flow Control GE Stacked Disc CCI Pocket Strainer SA ~1800 ft2/Train ~800 ft2/Pump ~6000 ft2 Total CS Setpoint 9.5 psig ~21.5 psig 2.8 psig 16 Calvert Cliffs Chemical Effects Testing & Option 2b Refined Closure Plan

Differences STP - VOGTLE - CCNPP

• Analytical Topic STP VOGTLE CCNPP Debris Generation Casa Grande BADGER Break Size/Orientation Search Algorithm 2, 45°increments Debris Transport Casa Grande NARWHAL Chemical Precipitate Qty Bounding Test NARWHAL Break-Specific Analysis Precipitation Timing Not Credited ANL Solubility Precipitate 140° Aluminum Passivation Not Credited Credited Not Credited Core Flow / Blockage FIDOE/RELAP5-3D WCAP-17788 WCAP-16793 Critical Break CFP Entered Critical Break GSI-191 Risk Quantification Size Frequency into PRA Size Frequency Strainer HL Protocol Flume Tank CCI MFTF 17 Calvert Cliffs Chemical Effects Testing & Option 2b Refined Closure Plan

Status of Calvert Cliffs Analysis

• Calculation Revisions

- In Owner Acceptance Review

• Debris Generation - 4 size distribution for Mineral Wool debris

- In process

• Revised Debris Transport Calculation

• Revised WCAP-16530 Chemical Precipitate Calculation

• Revised LOCADM Calculation

• Maximum Allowable Strainer Head Loss Calculation

• Revised Strainer Bypass Calculation

- Scheduled

• Formal Risk-Informed Analysis Calculations

• Update Ex-Vessel Downstream Effects Calculations

• Plan for GL 2004-02 Response

- Commitment Change Letter

- Perform Risk-Informed Analyses: March to June 2016

- Prepare Final Submittal: October 2015 to July 2016

- Submit Final Response: August 2016 18 Calvert Cliffs Chemical Effects Testing & Option 2b Refined Closure Plan

Questions/Concerns

• Jointly Review Issues, Questions, and Concerns for Future Communication 19 Calvert Cliffs Chemical Effects Testing & Option 2b Refined Closure Plan

Next Steps

• Finalize Update of Deterministic Calculations

• Present Formal Risk-Informed GSI-191 Analysis and Results

• Desire Next Meeting - April 2016 20 Calvert Cliffs Chemical Effects Testing & Option 2b Refined Closure Plan

Calvert Cliffs GSI-191 Program Strainer Head Loss Testing and Option 2b Closure Approach December 2015

Agenda

• Introductions

• Objectives for Meeting

• Discussion of Strainer Chemical Effects Head Loss Testing

• Discussion of Option 2b Simplified Risk-Informed Closure Plan

• Status of Calvert Cliffs Work

• Staff Questions & Concerns

• Schedule for Future Periodic Meetings 1 Calvert Cliffs Chemical Effects Testing & Option 2b Refined Closure Plan

CCNPP Attendees

• Mike Gahan - Engineering Manager

• Andre Drake - Lead Responsible Engineer GSI-191

• Jim Landale - Lead PRA Engineer

• Ken Greene - Licensing Engineer

• Craig Sellers - Project Manager GSI-191

• Steve Kinsey - Strainer Chemical Effects Head Loss Testing

• Eric Federline - Project Support & Testing

• Patrick Romine - Project Support & Testing 2 Calvert Cliffs Chemical Effects Testing & Option 2b Refined Closure Plan

Objectives of this Meeting

• Discussion of Strainer Chemical Effects Head Loss Testing

• Presentation of Calvert Cliffs Simplified Risk-Informed Approach

• Capture Staff Issues and Concerns

• Discuss Next Steps 3 Calvert Cliffs Chemical Effects Testing & Option 2b Refined Closure Plan

Strainer Head Loss Testing

• CCNPP Conducted 7 Strainer Head Loss Tests in 2010

- Performed in CCI Multi-Function Test Facility (MFTF) in Switzerland

- Debris Preparation in Accordance with CCI Protocols

• Fiber disintegrated into Fines using high pressure jet

- NRC observed CCI debris preparation protocols

- Debris introduced in 5 batches

• Each batch 20% of particulate followed by 20% of fiber

• First batch included 100% of Marinite

- Tests included WCAP-16530 Chemical Precipitate Surrogate

• WCAP surrogate prepared in accordance with WCAP guidance

• WCAP surrogate introduced via metering pump

- Flow Rate

• 5000 gpm equivalent prior to chemical addition (Design)

• 2400 gpm equivalent for chemical addition

- 820 gpm HPSI, 600 to 1000 gpm per EOP-5

- 1580 gpm CS (One CS Pump)

• One CS pump secured at containment pressure < 2.8 psig

• Containment Response calculation shows sump temperature > 150°F at 2.8 psig

• Sodium Aluminum Silicate does not precipitate until sump temperature < 140°F

• Optional flow sweep prior to test termination 4 Calvert Cliffs Chemical Effects Testing & Option 2b Refined Closure Plan

Strainer Head Loss Testing (continued)

• Test #1 Included Fine and Small Fibrous Debris

- Maximum Head Loss 1.75 inches of water

- Non-Uniform Debris Deposition

Conclusion:

Testing with Small Pieces is Non-Conservative

- Results of Test #1 were Rejected as Non-Conservative 5 Calvert Cliffs Chemical Effects Testing & Option 2b Refined Closure Plan

Strainer Head Loss Testing (continued)

• Remaining Tests Used Only Fine Fibrous Debris

- Full load of particulates and precipitates

- Test for Success Campaign

- Break-throughs experienced during each test 6 Calvert Cliffs Chemical Effects Testing & Option 2b Refined Closure Plan

Strainer Head Loss Testing (continued)

• Test 6 Rejection

- Test 6 was rejected in 2010

- Documented basis for rejection was limited

- Email archives from period searched

• Significant discussion of improper agitation observed

• Use of the hand held drill was lifting the debris within the Test Bed and creating a new profile that was considered not to be consistent with previous and subsequent testing.

• A formal evaluation of the test was performed and additional guidance on agitation control was prepared.

• After communication with the CCNPP project team the results of Test 6 were rejected.

• This rejection was performed before proceeding with Test 7.

- This has been documented and added to test files at CCNPP 7 Calvert Cliffs Chemical Effects Testing & Option 2b Refined Closure Plan

Strainer Head Loss Testing (continued)

• Test Debris Types & Equivalent Quantities

• Test Head Loss Results (ft-water)

Test Test Debris HL CS HL Total HL Debris Type 3 4 5 7 2 0.05 0.28 0.33 3 3.165 0.28 3.445 Nukon 167 ft3 36 ft3 88 ft3 61.5 ft3 4 0.599 0.28 0.879 Thermal Wrap 154 ft3 227 ft3 227 ft3 227 ft3 5 1.211 0.28 1.491 Temp-Mat 3.61 ft3 3.61 ft3 3.61 ft3 3.61 ft3 7 0.656 0.28 0.936 Generic LDFG 44.5 ft3 4.1 ft3 4.1 ft3 0 ft3 Mineral Wool 0 ft3 0 ft3 0 ft3 0 ft3 Lead Blanket Cover 0 ft3 0 ft3 0 ft2 564.5 ft2

• Maximum Allowable Strainer Head Loss Epoxy Particulate 2 ft3 1.5 ft3 2 ft3 1.5 ft3 - Currently Under Development IOZ Particulate 5.9 ft3 4.8 ft3 5.9 ft3 4.8 ft3 - Limiting Failure Mode is Deaeration Unqual Part 2 ft3 1.3 ft3 2 ft3 1.3 ft3

- Will range 1.75 to 2.5 ft-water Latent Particulate 1.275 ft3 1.275 ft3 1.275 ft3 1.275 ft3 Marinite 0.2 ft3 0.2 ft3 0.2 ft3 0.2 ft3 NaAlSi3O8 59.48 lbs 47.70 lbs 54.1 lbs 56.8 lbs

• Test 5 Test with Highest Acceptable Head Loss 8 Calvert Cliffs Chemical Effects Testing & Option 2b Refined Closure Plan

Strainer Head Loss Correlation Demonstrates Head Loss Proportional to Mass of Fine Fiber

• Plot of Head Loss -vs- Fiber Mass produces well correlated curve fit

• Plot includes clean strainer head loss

• Empirical Correlation based on Calvert Cliffs Prototypical Strainer Head Loss Testing Head Loss Data - Test Data + Clean Screen 2

y = 0.4444ln(x) + 1.1646 R² = 0.9949 Fine Fiber Mass (kg) 1.5 1

0.5 Total HL Log. (Total HL) 0 0 0.5 1 1.5 2 2.5 3 3.5 4 Head Loss (ft-water) 9 Calvert Cliffs Chemical Effects Testing & Option 2b Refined Closure Plan

Simplified Risk-Informed Approach Define Threshold Break Size

• Identify Applicable Strainer Chemical Effects Head Loss Test

- WCAP-16530 Chemical Surrogates

• Identify Smallest Break(s) that Generate Equivalent Quantity of Fine Fibrous Debris as used in Applicable and Acceptable Head Loss Test

- Also key criteria

• Quantity of Particulate for Each Break

• Quantity of WCAP-16530 Precipitate for Each Break

• Breaks That Produce Less Debris Than Tested are Acceptable Through Deterministic Analysis

• Breaks That Produce More Debris Than Tested are Addressed Probabilistically (Risk-Informed)

- The ID of the smallest break that produces more debris than tested is defined as the Threshold Break Size 10 Calvert Cliffs Chemical Effects Testing & Option 2b Refined Closure Plan

Simplified Risk-Informed Approach Calculate CDF & LERF

• CDF and LERF are taken from the Calvert Cliffs PRA Model of Record.

• CDF Determined from LOCA Frequency for Threshold Break Size

- Apportion LOCA Frequency Across Welds Threshold Break Size

- Interpolate within NUREG-1829 Intervals as needed for Break Size

- CDF = Apportioned LOCA Frequency for Breaks that produce more debris than tested

- Sensitivities on interpolation and LOCA Frequency Aggregation Methods

• LERF approach is to obtain a CDF multiplier from the Calvert Cliffs LERF model that is bounded by a worst case accident sequence for the Threshold Break Size for non SBO conditions.

• Compare CDF, CDF, LERF, and LERF results against Reg Guide 1.174 criteria for Region III.

• Verify other requirements (safety margin, defense in depth) of Reg Guide 1.174 are met.

11 Calvert Cliffs Chemical Effects Testing & Option 2b Refined Closure Plan

Simplified Risk-Informed Approach (Continued)

Deterministic Analysis

• Breaks Acceptable Through Deterministic Analysis

- Bounding Analyses

• NEI 04-07

- Limiting Single Failure

• All HPSI pumps running

• Credit for Operator Actions in EOPs

- Secure one CS pump

• Failure of LPSI pump to trip being resolved through plant modification

- Safety Related Calculations

• Calvert Cliffs GSI-191 calculations prepared in accordance with Appendix B QA program 12 Calvert Cliffs Chemical Effects Testing & Option 2b Refined Closure Plan

Simplified Risk-Informed Approach (continued)

Identify Applicable Head Loss Test

• Test 5 and DEGB @ ISI 30-RC-11A-6 (Crossover Leg at RCP Suction Elbow)

- Test 5 used equivalent of 825.7 lbm Fiber Fines

- Use 800 lbm Acceptance Criterion

- DEGB @ ISI 30-RC-11A-6 generated 797.8 lbm Fiber Fines Material Lead Thermal Generic Mineral Epoxy Alkyd Latent Nukon Temp-Mat Blanket IOZ Part. Marinite NaAlSi3O8 Wrap LDFG Wool Part. Part. Part.

Cover 210.9# 543.2# 42.9# 28.6# 2 ft3 5.9 ft3 2 ft3 Test 5 0# 0# 3 1.275 ft3 0 ft3 54.1 lbs E-Glass 825.7 lbm 9.9 ft ISI 309.6# 249.8# 30.2# 179.9# 1.21 ft3 2.22 ft3 1.74 ft3 22.58# 0# 1.275 ft3 0.12 ft3 65.8 lbs 30-RC-11A-6 E-Glass 769.5 lbm 5.17 ft3

• Test 5 had

- 56 lbm more E-Glass fiber fines

- 22.58 lbm less mineral wool

• Mineral wool 2.8% of fine fiber quantity

• CHLE investigatory tests showed no notable head loss impact from mineral wool

- 73% more failed coatings & latent particulate

- 0.12 ft3 less Marinite

- 82% of NaAlSi3O8 precipitate

• All tests experienced debris bed break-throughs relieving P before 100% WCAP-16530 surrogate precipitates introduced 13 Calvert Cliffs Chemical Effects Testing & Option 2b Refined Closure Plan

Simplified Risk-Informed Approach (continued)

Identify Small Breaks that Produce Sufficient Debris

• Risk-Informed Debris Generation Calculation Results

- Breaks Analyzed at 437 Circumferential Welds

- Longitudinal Welds Currently Being Analyzed

- ISI 30-RC-11A-6 is break #25 below DEGB Fiber Fines Mass for 70 Largest Breaks 1600 Loop 11 Hot Leg DEGB at Base of SG 1400 1200 Loop 12 Mass od Fiber Fines (lbm) 1000 RCS Loop DEGBs in RCP Bays 800 600 RCS Loop DEGBs at Rx Nozzles 400 Smaller 200 Breaks 0

0 10 20 30 40 50 60 70 Break Number Fiber Mass Acceptance Criterion 14 Calvert Cliffs Chemical Effects Testing & Option 2b Refined Closure Plan

Simplified Risk-Informed Approach (continued)

Calculate CDF - Preliminary Results

• Use Conservative Approach

• Linear Interpolation

- Smallest break that threatens strainer LOCA Break Size Geometric Arithmetic Category (>in.) Mean Mean performance - 30 DEGB 1 0.5 1.90E-03 1.00E-02

- NUREG-1829 LOCA Frequencies 2 1.5 4.20E-04 3.00E-03

- Equally Apportion LOCA Frequency Across 3 3 1.60E-05 7.30E-05 4 6.75 1.60E-06 9.40E-06 RCS Welds 5 14 2.00E-07 2.40E-06

• Degradation mechanisms are Design and Construction for all 126 RCS welds 5.5 30 4.37E-08 1.58E-06

• PWSCC also on 8 RCS welds 6 31.5 2.90E-08 1.50E-06 LOCA Break Size Geometric Arithmetic

1. Welds #Failed CDF GM CDF AM Category (in.) Mean1 Mean2 126 24 8.32E-09 3.00E-07 1 0.5 1.90E-03 1.00E-02 2 1.5 4.20E-04 3.00E-03

• Log-Log Interpolation 3 3 1.60E-05 7.30E-05 LOCA Break Size Geometric Arithmetic 4 6.75 1.60E-06 9.40E-06 Category (>in.) Mean Mean 5 14 2.00E-07 2.40E-06 1 0.5 1.90E-03 1.00E-02 6 31.5 2.90E-08 1.50E-06 2 1.5 4.20E-04 3.00E-03 Notes:

3 3 1.60E-05 7.30E-05

[1] Taken from Table 7-19 of NUREG-1829 4 6.75 1.60E-06 9.40E-06

[2] Taken from Table 7-13 of NUREG-1829 5 14 2.00E-07 2.40E-06

- 126 Welds 30 5.5 30 3.93E-08 1.55E-06 6 31.5 2.90E-08 1.50E-06

- 24 Welds 30 Threaten Strainer # Welds #Failed CDF GM CDF AM Performance 126 24 7.48E-09 2.96E-07 15 Calvert Cliffs Chemical Effects Testing & Option 2b Refined Closure Plan

Differences STP - VOGTLE - CCNPP

• Physical Item STP VOGTLE CCNPP NSSS Westinghouse Westinghouse CE Circumferential &

RCS Piping Welds Circumferential Welds Circumferential Welds Longitudinal Welds RCS Piping ID 31 31 42 & 30 ECCS Trains 3 2 2 Strainer Config. 3 combined 4 separate 1 combined Strainer Design PCI Flow Control GE Stacked Disc CCI Pocket Strainer SA ~1800 ft2/Train ~800 ft2/Pump ~6000 ft2 Total CS Setpoint 9.5 psig ~21.5 psig 2.8 psig 16 Calvert Cliffs Chemical Effects Testing & Option 2b Refined Closure Plan

Differences STP - VOGTLE - CCNPP

• Analytical Topic STP VOGTLE CCNPP Debris Generation Casa Grande BADGER Break Size/Orientation Search Algorithm 2, 45°increments Debris Transport Casa Grande NARWHAL Chemical Precipitate Qty Bounding Test NARWHAL Break-Specific Analysis Precipitation Timing Not Credited ANL Solubility Precipitate 140° Aluminum Passivation Not Credited Credited Not Credited Core Flow / Blockage FIDOE/RELAP5-3D WCAP-17788 WCAP-16793 Critical Break CFP Entered Critical Break GSI-191 Risk Quantification Size Frequency into PRA Size Frequency Strainer HL Protocol Flume Tank CCI MFTF 17 Calvert Cliffs Chemical Effects Testing & Option 2b Refined Closure Plan

Status of Calvert Cliffs Analysis

• Calculation Revisions

- In Owner Acceptance Review

• Debris Generation - 4 size distribution for Mineral Wool debris

- In process

• Revised Debris Transport Calculation

• Revised WCAP-16530 Chemical Precipitate Calculation

• Revised LOCADM Calculation

• Maximum Allowable Strainer Head Loss Calculation

• Revised Strainer Bypass Calculation

- Scheduled

• Formal Risk-Informed Analysis Calculations

• Update Ex-Vessel Downstream Effects Calculations

• Plan for GL 2004-02 Response

- Commitment Change Letter

- Perform Risk-Informed Analyses: March to June 2016

- Prepare Final Submittal: October 2015 to July 2016

- Submit Final Response: August 2016 18 Calvert Cliffs Chemical Effects Testing & Option 2b Refined Closure Plan

Questions/Concerns

• Jointly Review Issues, Questions, and Concerns for Future Communication 19 Calvert Cliffs Chemical Effects Testing & Option 2b Refined Closure Plan

Next Steps

• Finalize Update of Deterministic Calculations

• Present Formal Risk-Informed GSI-191 Analysis and Results

• Desire Next Meeting - April 2016 20 Calvert Cliffs Chemical Effects Testing & Option 2b Refined Closure Plan