ML13038A543

Chemical Effects Head Loss Experiment (Chle) Test Protocol for Calvert Cliffs Nuclear Power Plant (CCNPP-CHLE-002, Revision 0d)

ML13038A543
Person / Time
Site:	Calvert Cliffs
Issue date:	01/24/2013
From:	Sellers C - No Known Affiliation
To:	Nadiyah Morgan Plant Licensing Branch 1
Morgan N NRR/DORL/LPL1-1 301-415-1016
References
CCNPP-CHLE-002, Rev 0d
Download: ML13038A543 (11)

Text

CHEMICAL EFFECTS HEAD LOSS EXPERIMENT (CHLE)

TEST PROTOCOL for Calvert Cliffs Nuclear Power Plant CCNPP-CHLE-002, Revision 0d January 24, 2013 Prepared by: Reviewed by:

Craig D. Sellers Stephen Kinsey & Josh Wargo

Chemical Effects Head Loss Experiment (CHLE)

Test Protocol for Calvert Cliffs Nuclear Power Plant CCNPP-CHLE-002 Revision 0d, January 24, 2013 REVISION HISTORY Log Revision Description 0d Issue for NRC Review i

Chemical Effects Head Loss Experiment (CHLE)

Test Protocol for Calvert Cliffs Nuclear Power Plant CCNPP-CHLE-002 Revision 0d, January 24, 2013 Contents 1.0 Purpose ......................................................................................................................................................................... 1 2.0 Overall experimental protocol............................................................................................................................. 1 3.0 Specific Protocol Topics ......................................................................................................................................... 2 3.1 Experimental Facility Design .......................................................................................................................... 2 3.2 Debris Preparation and Introduction .......................................................................................................... 4 3.2.1 Fibrous Debris ............................................................................................................................................. 4 3.2.2 Particulate Debris ....................................................................................................................................... 4 3.2.3 Coatings .......................................................................................................................................................... 4 3.2.4 Reactive Materials ...................................................................................................................................... 4 3.3 Fluid Chemistry ..................................................................................................................................................... 5 3.4 Fluid Temperature ............................................................................................................................................... 5 3.5 Head Loss Measurement ................................................................................................................................... 5 3.6 Chemical Effects Head Loss .............................................................................................................................. 5 4.0 Method for Applying Results ................................................................................................................................ 6 4.1 Large Temperature Dependent Chemical Effects Head Loss ............................................................. 6 4.2 Small Temperature Dependent Chemical Effects ................................................................................... 7 4.3 No Chemical Effects ............................................................................................................................................. 8 5.0 References .................................................................................................................................................................... 8 List of Figures Figure 1: Schematic of Proposed CHLE Facility .......................................................................................................... 3 List of Tables Table 1: Detector Debris Bed Composition................................................................................................................... 5 ii

Chemical Effects Head Loss Experiment (CHLE)

Test Protocol for Calvert Cliffs Nuclear Power Plant CCNPP-CHLE-002 Revision 0d, January 24, 2013 1.0 PURPOSE The purpose of this document is to describe the protocol planned to be implemented for the chemical effects head loss experiments (CHLE) for the Calvert Cliffs Nuclear Power Plant (CCNPP).

This document presents the methods for performing the experiments, the processes for which the test conditions for each experiment will be established, and the methods for applying the experimental results. The plan for performing these experiments is described in a separate document.

2.0 OVERALL EXPERIMENTAL PROTOCOL The overall concept for the experiments is a long-term integrated chemical effects test with head loss measured throughout the test. A 30-day test duration is considered long-term for this experimental program.

Materials used in the test will be representative of the materials submerged in the containment pool and/or exposed to containment spray. These include destroyed insulation, qualified/unqualified coatings, concrete, latent debris and other miscellaneous materials in containment. The material quantities will be scaled such that ratio of the test fluid volume or mass to the volume or mass of materials immersed in the pool fluid or the surface area of materials exposed to pool or spray fluid is consistent with the ratio of the volume or mass of the post-LOCA pool to the submerged material volume or exposed material surface area at CCNPP. This will maintain consistent chemistry concentrations.

The test chemistry will begin with the initial post-LOCA pool chemistry expected at CCNPP. A scaled quantity of sodium tetraborate decahydrate (NaTB) buffer will be allowed to dissolve in the test chamber to simulate the dissolution of buffer in the plant. Strong acids from the radiologic decomposition of water and electrical cables1 may be added periodically to the test at a rate similar to which these acids are expected to be produced at CCNPP. No additional chemical or pH control will occur. The test chemistry will be allowed to evolve as it would in the post-LOCA environment at CCNPP. Water chemistry will be periodically sampled and tested for chemical contents.

The test temperature conditions will replicate the CCNPP post-LOCA temperature profile for the specific break conditions being simulated in the experiment. The last portion of the test will be used to investigate low temperature chemical effects by reducing the temperature in stages until room temperature is achieved.

1 The radiologic decomposition of water and electrical cable insulation and resulting production of strong acids assumes significant core damage. The assumption of core damage is not consistent with successful ECCS performance.

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Chemical Effects Head Loss Experiment (CHLE)

Test Protocol for Calvert Cliffs Nuclear Power Plant CCNPP-CHLE-002 Revision 0d, January 24, 2013 Head loss will be monitored throughout the test using a fiber and particulate debris bed formed on a flat perforated plate that has proven to be a good detector of head loss caused by chemical effects

[Ref. 1]. The debris bed will not necessarily be representative of the debris bed expected on the sump strainer or within the reactor core at CCNPP but it will include similar fibrous material. The flow rate through the debris bed will yield a higher approach velocity than that expected at the CCNPP sump strainer and fuel assemblies. The flow rate used will be specified to increase the sensitivity of the debris bed for identification of head loss due to chemical effects.

3.0 SPECIFIC PROTOCOL TOPICS 3.1 Experimental Facility Design The planned design of the experimental facility includes the following major components:

1) Reaction Chamber - This chamber contains the material coupons and buffering agent and is used to simulate the containment pool for the long-term test. Test chamber allows for full submergence of coupons as well as exposure to nozzles simulating containment spray.

2) Vertical Head Loss Loop - This loop contains the flat perforated plate and debris bed across which chemical effects head loss will be detected.

3) Heat Exchanger Loop - This loop contains a cool-down heat exchanger to investigate the potential for chemical precipitation in the shutdown cooling heat exchangers.

4) Primary Heater - This heater controls the temperature of the reaction chamber and heats recirculation fluid from the head loss and heat exchanger loops prior to injection into the reaction chamber.

5) Recirculation Pumps and Valves - The reaction chamber, vertical head loss loop, and heat exchanger loop have independent recirculation pumps with valves to control flow direction.

6) Initial Solution Preparation Chamber - This chamber contains the initial borated water solution simulating the reactor coolant and safety injection fluid and will be discharged into the reaction chamber at the beginning of each experiment to simulate the LOCA.

A schematic diagram of the planned loop is shown below.

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Chemical Effects Head Loss Experiment (CHLE)

Test Protocol for Calvert Cliffs Nuclear Power Plant CCNPP-CHLE-002 Revision 0d, January 24, 2013 Figure 1: Schematic of Proposed CHLE Facility Note: This is an early figure and does not include a pressurized reaction tank or a heat exchanger loop.

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Chemical Effects Head Loss Experiment (CHLE)

Test Protocol for Calvert Cliffs Nuclear Power Plant CCNPP-CHLE-002 Revision 0d, January 24, 2013 3.2 Debris Preparation and Introduction 3.2.1 Fibrous Debris Fibrous debris, other than the fiber in the vertical head loss loop debris bed, will be cut from new bats of material, boiled to release the binders, dried, and weighed to the quantity specified in the test plan. The fiber samples will be placed in stainless steel mesh containers or otherwise secured to prevent fiber migration into the vertical head loss or heat exchanger loops which could affect head loss in the debris bed. The objective is to limit the impact on head loss to that head loss caused by chemical effects.

3.2.2 Particulate Debris Particulate debris will have no unique preparation process and will be placed in stainless steel mesh containers or otherwise secured to prevent migration into the vertical head loss or heat exchanger loops which could affect head loss in the debris bed. The objective is to limit the impact on head loss to that head loss caused by chemical effects.

3.2.3 Coatings Qualified coatings and unqualified coatings exposed to the break jet debris will be prepared by applying the coating to a flexible surface and peeling off the flexible surface after drying. The objective will be to produce as small a chip or particle as possible. The chips and/or particles removed from the flexible surface will be weighed and placed in stainless steel mesh containers or otherwise secured to prevent migration into the vertical head loss or heat exchanger loops which could affect head loss in the debris bed. The objective is to limit the impact on head loss to that head loss caused by chemical effects.

Unqualified coatings not exposed to the break jet will be applied to a coupon of substrate similar to that which they are applied at CCNPP. The coupons coated with the surface area specified in the test plan will be introduced into the reaction chamber prior to initiation of each experiment. These coated coupons will be allowed to dissolve and/or corrode normally in the experimental solution.

3.2.4 Reactive Materials Coupons of reactive materials (aluminum, galvanized steel, copper, and concrete) will be placed in the reaction chamber prior to initiation of each experiment. These coupons will be allowed to dissolve and/or corrode normally in the experimental solution.

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Chemical Effects Head Loss Experiment (CHLE)

Test Protocol for Calvert Cliffs Nuclear Power Plant CCNPP-CHLE-002 Revision 0d, January 24, 2013 3.3 Fluid Chemistry The fluid chemistry will be established in the initial solution preparation chamber and will match the borated water solution expected at the beginning of the LOCA. This includes any expected lithium and/or silica concentrations.

The NaTB buffer will be placed in the reaction chamber prior to the initiation of each experiment and will be allowed to dissolve naturally in the experimental fluid. Strong acids from the radiologic decomposition of water and electrical cables may be added periodically to the test at a rate similar to which these acids are expected to be produced at CCNPP. No additional chemical or pH control will occur.

3.4 Fluid Temperature The fluid temperature will match the sump temperature profile specified in the test plan with a variance of +/-5°F.

3.5 Head Loss Measurement Chemical effects head loss will be indicated by measurement of head loss across a debris bed. The debris bed formed on the flat plate screen is intended to provide a highly efficient filtering media capable of readily identifying the head loss impact of potential precipitates on a qualitative basis.

Since the head loss that is being monitored during the course of the test is meant to provide only a qualitative indication of chemical effects impact, the composition of the bed is designed more for filtering and not as a prototypical debris bed for CCNPP. The goal in the debris bed formation is to establish a stable head loss prior to the beginning of the integrated test.

Table 1: Detector Debris Bed Composition Substance Quantity (in grams)

NUKON 16 +/- 0.1 Silicon carbide 80 +/- 0.1 The debris loading for this particular configuration results in a particulate to fiber mass ratio of 5:1.

3.6 Shakedown Testing A number of shakedown tests will be performed to verify correct design of the test facility and to demonstrate effective and repeatable performance of the head loss column and debris bed.

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Chemical Effects Head Loss Experiment (CHLE)

Test Protocol for Calvert Cliffs Nuclear Power Plant CCNPP-CHLE-002 Revision 0d, January 24, 2013 3.7 Baseline Testing A Baseline test will be performed with the appropriate fluid chemistry but without the insulation debris and potentially reactive materials which will provide non-chemical effects long term head loss across the test temperature range.

3.8 Chemical Effects Head Loss Testing A chemical effects head loss is defined as any change in head loss not attributable to expected non-chemical effects reasons. Such reasons are changes in fluid viscosity and density with changes in fluid temperature.

Another reason is the gradual steady increase in debris bed head loss observed in most long term head loss tests. This is termed debris bed degradation. The cause of this gradual head loss increase is debris bed compaction and the subsequent decrease in porosity.

The chemical effects head loss experimental test will be performed with the appropriate fluid chemistry and the potentially reactive materials which will provide total long term head loss across the test temperature range. Differences in this test and the baseline test will be deemed chemical effects head loss.

4.0 METHOD FOR APPLYING RESULTS The method for applying the test results depends on the form of the results. Three possible forms of results are foreseen:

4.1 Large Temperature Dependent Chemical Effects Head Loss One form of result that is not expected but must be recognized as possible is a large chemical effects head loss on the detector debris bed at a specific temperature. Large chemical effects head loss is defined as a detector debris bed head loss increase of greater than 100% as compared to the baseline test head loss with no chemical effects. For example, head loss through the debris bed initially 1 ft-water that increases to 2 ft-water for a reason that cannot be explained by density and/or viscosity changes with temperature or by long-term bed degradation, would be considered a large chemical effects head loss.

In this case, CCNPP will apply the WCAP-16530 chemical effects test head loss to the CCNPP suction strainer at all temperatures at or below the temperature at which the chemical effects head loss is observed. This WCAP-16530 head loss impact will be based on prototype strainer hydraulic testing using surrogate precipitates generated in accordance with the WCAP-16530 model.

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Chemical Effects Head Loss Experiment (CHLE)

Test Protocol for Calvert Cliffs Nuclear Power Plant CCNPP-CHLE-002 Revision 0d, January 24, 2013 It is noted that the CCNPP prototypical strainer hydraulic testing produced strainer debris bed head loss values less than 10 mbar (~0.33 ft-water) prior to the introduction of WCAP-16530 surrogate precipitates. The head loss increased to over 690 mbar (>23 ft-water) which is an approximate 6800% increase. Therefore applying this total WCAP-16530 head loss when a >100% increase in detector debris bed head loss is conservative.

4.2 Small Temperature Dependent Chemical Effects One possible form of result that is more likely to be observed than the large impact is a small chemical effects head loss on the detector debris bed at a specific temperature. Small chemical effects head loss is defined as a detector debris bed head loss increase of greater than or equal to 10% and less than or equal to 100% compared to the baseline test.

In this case, CCNPP will apply a ratio of the WCAP-16530 chemical effects test head loss to the CCNPP suction strainer at all temperatures at or below the temperature at which the chemical effects head loss is observed. The ratio will be the percentage increase in chemical effects head loss observed over the non-chemical effects head loss observed.

Chemical Effects Strainer Head Loss = % head loss increase due to chemical effects observed in test x WCAP-16530 head loss.

For example, if the head loss through the debris bed in the test is initially 1 ft-water but increases to 1.5 ft-water for a reason that cannot be explained by density and/or viscosity changes with temperature, head loss increase due to chemical effects would be a 50% increase. Thus, if during the CCNPP prototypical strained hydraulic testing the stabilized strainer head loss prior to introduction of WCAP-16530 precipitates was 2 ft-water and after introduction of WCAP-16530 precipitates it stabilized at 6 ft-water, the strainer head loss attributable to chemical effects now becomes 2 ft-water + 0.5*(6 ft-water - 2 ft-water) = 4 ft-water.

The CCNPP prototypical strainer hydraulic testing produced strainer debris bed head loss values less than 10 mbar (~0.33 ft-water) prior to the introduction of WCAP-16530 surrogate precipitates.

The head loss increased to over 690 mbar (>23 ft-water) which is an approximate 6800% increase.

Therefore applying a percentage of this total WCAP-16530 head loss based on a >0% to 100%

increase in detector debris bed head loss is conservative. For example, based on the ~0.33 ft-water debris bed head loss observed during prototypical strainer testing, a 20% increase in detector debris bed head loss translates into 0.33 + 0.2*(23 - 0.33) = 4.86 which is a 1400% increase in debris bed head loss.

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Chemical Effects Head Loss Experiment (CHLE)

Test Protocol for Calvert Cliffs Nuclear Power Plant CCNPP-CHLE-002 Revision 0d, January 24, 2013 4.3 No Chemical Effects One form of test results is that no chemical effects head loss or in-vessel chemical reaction is observed. A head loss variation of less than +10% compared to the baseline test is considered no chemical effects head loss. If this is the result, chemical effects can be ignored at CCNPP.

5.0 REFERENCES

1. Design Calculation CA07055, Rev. 0001 (ALION-REP-CCNPP-7311-001, CCNPP Chemical Effects Vertical Loop Head Loss Test Report, Revision 2).

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