ML16095A078

Slides for the WCGS Meeting Discussion 4/12/16 (CAC No. MC4731)

ML16095A078
Person / Time
Site:	Wolf Creek
Issue date:	04/12/2016
From:	Lyon C F Plant Licensing Branch IV
To:
Lyon C F, NRR/DORL/LPLIV-1
References
CAC MC4731
Download: ML16095A078 (19)

Text

Fiber Penetration and Head Loss Testing Approach Meeting with NRC April 12, 2016 1 Outline *Purpose of Meeting -Communicate Wolf Creek testing approach for fiber penetration and strainer head loss *Agenda -Overview of Wolf Creek Testing Program -Fiber Penetration Testing Approach -Strainer Head Loss Testing Approach 2 Strainer B Strainer A Overview of Sump Strainers 3 Overview of Testing Program *Perform tank tests at Alden for fiber penetration and strainer head loss *Use prototypical strainer modules for head loss testing *Modify prototypical strainer modules for penetration testing to eliminate bridging *Test strainer modules have same disk size, perforation size and core tube diameter as the plant strainer *Maintain turbulence level for complete transport of fine debris 4 Flow Direction Debris Introduction

& Mixing Section Plenum Box Test Strainer To Flow Loop Overview of Testing Program (cont'd) *Use methods previously reviewed by the NRC -Similar to recent tank tests for Florida Power & Light at Alden witnessed by the NRC staff *Follow NEI guidance on fibrous debris preparation* *Determine threshold debris load that meets in-vessel and head loss criteria using test results *Projected test start date: May 9, 2016 5 ZOI Fibrous Debris Preparation: Processing, Storage and Handling, Rev. 1, Jan 2012 (ADAMS Accession No. ML120481057)

Fiber Penetration Testing Approach *Perform a fiber-only penetration test *Collect time-dependent fiber penetration data considering prompt and long-term penetration *Develop a curve fit from testing data to characterize rates of prompt and long-term penetration *Apply curve fit to quantify total fiber penetration for the fiber load of each break at bounding plant conditions *Determine compliance with the in-vessel fibrous debris quantity limit (WCAP-17788) *Perform 30-day extrapolation for total fiber penetration as input to ex-vessel downstream effects analysis 6 Prevent Bridging for Penetration Testing *Modified prototype strainer to eliminate possible bridging of fiber between adjacent disks, and between the strainer and its surrounding walls *Preventing bridging in fiber-only penetration testing allows fiber to reach the perf plates and is conservative 7 *Test strainer module modification -Remove every other disk -Remove seismic cables -Increase distance between edges of test strainer and surrounding walls *Measured fiber penetration per unit area will be applied to the plant strainer surface area Penetration Testing Conditions *Prototypical pool chemistry at max pH (9.6) *Testing temperature 120F +/- 5F *Max strainer approach velocity (0.00612 ft/s) *Prototypical fibrous debris concentrations -Pool fiber concentration defined as total fiber quantity divided by pool volume -Fiber concentration in test tank maintained at or below the prototypical value to allow debris bed to form slowly 8 Fiber Preparation and Introduction *Only fines will be used for penetration testing -Nukon sheets baked single-sided into half thickness and cut into 2" x 2" cubes -Debris preparation per the latest NEI Guidance* *Fiber will be added to the test tank in batches *Batching size will increase gradually to facilitate fiber bed formation on test strainer *Total test fiber quantity will bound the max fiber load of largest DEGB 9 ZOI Fibrous Debris Preparation: Processing, Storage and Handling, Rev. 1, Jan 2012 (ADAMS Accession No. ML120481057)

Collect Time-Dependent Penetration Data *Penetrated fiber collected in 5-m filter bags *Each batch begins with a set of clean bags *To measure long-term penetration, extended runtime and multiple bag changes will be done for selected batches *Total runtime of the test exceeds duration from start of an accident to hot leg recirculation switchover *A curve-fit will be developed to adequately model and bound testing results *The curve-fit characterizes both prompt and long-term penetration 10 Head Loss Testing Approach *Measure debris bed head loss for debris loading of various break sizes on a prototypical test module -No modifications to test modules as done for penetration testing *Chemical debris will not be added until all conventional debris has been introduced to test tank and head loss allowed to stabilize *Perform flow sweeps for adjusting measured head losses to plant conditions -After adding all conventional debris and at end of test 11 Head Loss Testing Approach (cont'd) *Perform temperature sweep after adding all conventional debris to characterize debris bed *Head Loss Test Conditions: -Prototypical sump water chemistry at min pH (8.7) -Test temperature approximately 120F +/- 5F -Approach velocity from max strainer flow rate and net strainer surface area (0.00615 ft/s) *Two head loss tests planned -Test 1: Full Debris Load Test -Test 2: Thin Bed Test -Contingency test may be conducted depending on results of previous tests 12 Test 1: Full Debris Load Test *Fibrous and particulate debris batched into test tank as homogeneous mixtures *Addition of conventional debris ends when head loss is near prescribed value based on pump NPSH margin and strainer structural limit *No alternating additions of fiber fines and small pieces 13 Test 1: Full Debris Load Test (cont'd) *Cumulative conventional debris quantities of intermediate batches match debris loads of multiple break sizes -Head loss allowed to stabilize before continuing addition *Chemical debris batched into test tank after completing all conventional debris addition -Head loss allowed to stabilize after each addition 14 Test 2: Thin Bed Test *Particulate debris load for Test 2 will be informed by the threshold breaks identified in Test 1 *Particulate debris added to test tank at the beginning of test *Nukon fiber fines added in batches until thin-bed conditions are met *Chemical debris batched in afterwards 15 Test Debris Types Test Materials Debris Types at Plant Nukon *Nukon Insulation *Latent Fiber *Cerablanket *Fibrous Content of Thermolag Pulverized Acrylic or Silicon Flour (10 m) *IOZ, Epoxy and Alkyds *Foamglas *Particulate Content of Thermolag PCI PWR Dirt/Dust Mix* Latent Particulate Aluminum Oxyhydroxide Aluminum Precipitate Debris 16 The size distribution of "PCI PWR Dirt/Dust Mix" meets requirements in Appendix VII of NEI 04-07 for surrogate of latent particulate debris Quantity of Chemical Debris *Evaluated chemical precipitate quantities using deterministic method per WCAP-16530-NP-A -Max sump pool mass and temperature to increase aluminum release -Max pH to increase aluminum release -Conservatively higher aluminum inventory -Max quantities of E-Glass of largest DEGB 17 Closing *Wolf Creek is planning to use methods previously reviewed by the NRC staff *Penetration data will be used to develop a curve fit that can be applied to any debris load (up to max for WCNOC) *Head Loss test results will establish a threshold debris load *Analysis will determine the threshold debris load that meets both the in-vessel and head loss criteria *Threshold debris load will determine the break sizes that pass deterministically 18 Closing *Questions? 19