ML16095A078

Slides for the WCGS Meeting Discussion 4/12/16

ML16095A078
Person / Time
Site:	Wolf Creek
Issue date:	04/12/2016
From:	Lyon C Plant Licensing Branch IV
To:
Lyon C, 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 +/- 5 F *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 lo ng-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 t emperature 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?

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