ML18092A306
| ML18092A306 | |
| Person / Time | |
|---|---|
| Site: | 05200045 |
| Issue date: | 03/31/2018 |
| From: | GE-Hitachi Nuclear Energy Americas |
| To: | Office of New Reactors |
| References | |
| M180068 NEDO-33878, Rev 3 | |
| Download: ML18092A306 (106) | |
Text
Enclosure 3 M180068 NED0-33878, Revision 3, ABWR ECCS Suction Strainer Evaluation of Long-Term Recirculation Capability, March 2018 Class I (Public)
IMPORTANT NOTICE REGARDING CONTENTS OF THIS DOCUMENT Please Read Carefully The information contained in this document is furnished solely for the purpose(s) stated in the transmittal letter. The only undertakings of GEH with respect to information in this document are contained in the contracts between GEH and its customers or participating utilities, and nothing contained in th is document shall be construed as changing that contract. The use of this information by anyone for any purpose other than that for which it is intended is not authorized; and with respect to any unauthorized use, GEH makes no representation or warranty, and assumes no liability as to the completeness , accuracy, or usefulness of the information contained in this documenf
- HITACHI GE Hitachi Nuclear Energy NED0-33878 Class I (Public)
Revision 3 March 2018 Non-Proprietary Information - Class I (Public)
Licensing Technical Report ABWR ECCS SUCTION STRAINER EVALUATION OF LONG-TERM RECIRCULATION CAPABILITY I
Copyright 2018, GE-Hitachi Nuclear Energy Americas LLC I
All Rights Reserved GEH Public IPage 1 of 105
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INFORMATION NOTICE This is a non-proprietary version of the document NEDE-33878P Revision 3, which has the proprietary information removed. Portions of the document that have been removed are indicated by an open and closed bracket as shown here (( )).
IMPORTANT NOTICE REGARDING CONTENTS OF THIS REPORT Please Read Carefully This document provides certain details of the Emergency Core Cooling System Suction Strainers for the ABWR standard design. The information contained in the document is furnished to the NRC for the purpose of conducting its review for the renewal of the ABWR standard design certification . The use of this information by anyone for any other purpose than that for which it is intended is not authorized; and with respect to any unauthorized use, GEH makes no representation or warranty, and assumes no liability as to the completeness, accuracy, or usefulness of the information contained in this document.
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TABLE OF CHANGES Rev.# Date Revision Summary 0 02/2017 Initial Issue 1 05/2017 Revised to reduce proprietary information markings and correct some paragraph spacing which reduced the page count by one page. There are no other changes. Revision bars not used.
2 08/2017 Updated the ECCS suction strainer debris downstream assessment as follows: 1) The mission time for post LOCA function of RHR and HPCF was revised from 100 days to 30 days consistent with NRC guidance; 2) ASME QME-1 was credited as reference for ECCS pump performance qualification to ensure as-built SSCs will meet post LOCA requirements including debris loading; 3) Additional detail was provided for a mitigating feature to prevent settling of debris in instrument lines; 4) Clarification of RHR heat exchanger flow path and assessment of heat exchanger I performance under post LOCA debris loading was provided.
3 03/2018 In the proprietary NEDE, changed a reference in Section 2.1.3.2 from "2.1.3.2" to "2.1.3".
Updated References 18 and 34.
Appendix A.4.1, first bullet, added Reference 27 .
Updated the ECCS suction strainer debris downstream assessment description as follows :
- 1) Revised Appendix A.4.1, Auxiliary Equipment Evaluation, to reflect the assessment for instrument line plugging and wear is based on instrumentation line configuration and orientation and not system flow and materials settling velocities as is the criteria for process piping .
- 2) Revised Appendix A.4.1 , Auxiliary Equipment Evaluation, to reflect that this report is incorporated by reference in the GEH Public IPage 3 of 105
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Rev.# Date Revision Summary ABWR DCD Tier 2. This report imposes requirements on ABWR design.
- 3) Updated the Auxiliary Equipment Evaluation presented in Tables A-4 through A-8 to reflect that ECCS pump design is based on ECCS suction strainer sizing to prevent clogging of pump internal passages including mechanical seal assemblies. The ECCS pump manufacturer will specify cyclone separator performance and seal cooling line orifice hole size to prevent debris plugging.
- 4) Updated Tables A-4, A-5, and A-6 to correct subscripts for Iron Oxide.
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TABLE OF CONTENTS TABLE OF CHANGES ... .. .. .......... ... ...... ..... .. .... .. .. .. ........ .. ....... .. ................................ ...... 3 TABLE OF CONTENTS ... ..... ... ... .. ... .. .... .... ... .. ......................................................... ....... 5 LIST OF ILLUSTRATIONS .. .. .. .. .... .......... .. ................................ ............................ .......... 6 LIST OF TABLES ...... ........... ................................ .. ................................. ... ... .. ... ............. 6
1.0 INTRODUCTION
.. .. .. .. ... .. .......... .. .. .. ....... .................. ............ .... .. .......................... 7 1.1 Background ............................... .............. .. ......... ...... ... .. ......... .................... 7 1.2 Purpose ... .. ....... .... ..... .. ...... ... ...... .. ... ............ ........................................ ...... 9 1.3 Acronyms .. .. ......... ........ .......... ............................................... ... ... ............. 10 1.4 Definitions ......... .. ..... .. ... .. .. .... .......... .. .. ..... ... .. ........ .... .......................... ..... 11 1.5. Assumptions ........ ............ .. .......... ................................................ ... ... ..... . 13 2.0 DESIGN METHODS ........ ............ .. .. .. ...................................... .. .... ... ................ .. 15 2.1 Discussion ........................................ ... .. .. .. .. ... ............ .. ......... .. .......... ...... 15 2.1 .1 Debris Types / Quantities .. .... ... ....... .. ..... .. ... ... .... .. .. .... .... ... ...... ........ ..... 15 2.1.2 Selection of Bounding Strainer Design ............ .. ...... .. .. ...... ... .. .. ... .. .. .... . 19 2.1.3 Head Loss Evaluation ...... ........... .. .. .. ........... .. ................. ......... ... ... ... ... 20 3.0 DESIGN RESULTS & ACCEPTANCE CRITERIA ...... .. .......... .. .. .. ...... .. ..... /........ 28 1
3.1 Design Results .................... .. .... .. ....... ........ ... ..... .. ............................. .. ..... 28 3.1 .1 RHR Acceptance Criteria ... ....... .............. ... ... ... .. .. ............................... .... ..29 3.1 .2 HPCF Acceptance Criteria ...... ....... .... ... ..... ...... ..... ....... ......... ...... ...... ...... ..29 3.1.3 RCIC Acceptance Criteria .. ...................... .... .... .......... ..... .... .. ....... ........ ..... 30
4.0 CONCLUSION
S .............. ........ ........... .. .. ............................................... ... .......... 31
5.0 REFERENCES
.... ................ ......... ...... ........ .. .......................... .... .. ....... ............... 32 APPENDIX A DOWNSTREAM EFFECTS EVALUATION ...... ..... ......... .. .. ..................... 35 A.1 OVERVIEW .......... ...... ........... ...... ............ .. .... ................................... ........ ......... 35 A.2 ECCS SYSTEM DESCRIPTIONS AND MISSION TIMES ................ .... .............. 36 A.3 DEBRIS INGESTION ....................... ........ ... ............. ................................... .... .... 39 A.4 WEAR RATE AND COMPONENT EVALUATION .............................. ................ 41 A.4 .1 Auxiliary Equipment Evaluation ................ .. .. .. .. ............ ........................... . 41 A.5 REACTOR INTERNALS AND FUEL BLOCKAGE EVALUATION ...... .. ..... T ...... 46 GEH Public I Page 5 of 105
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LIST OF ILLUSTRATIONS FIGURE A-1, ABWR ECCS FLOW PATHS ..... ... ... ...... .... .... ... .. ......... ..... ... ... ......... .... ... 37 FIGURE A-2, LAYOUT OF ECCS COMPONENTS FOR DOWNSTREAM ASSESSMENT
............. .. ......... ......... ....... ..................................... ... ... ... .......... ...... ... ..... ... ... ..... .. 44 FIGURE A-3, NORMAL FUEL CHANNEL COOLING FLOW PATHS .. ... ..... ... ....... ....... 48 LIST OF TABLES Table 1: RMI Surface Area to Volume Ratio ... .......... ......... ....... .... ... ... .. .. .. .. ... .. .... ....... 14 0 0 0 0 0 0 0 0 0 0 0 Table 2: (( )) Pipe Insulation Debris Load ........... .......... .......... ..................... 16 Table 3: ABWR Debris Load Fractions ............... ........ ...... .... .... .... .. ....... ... ... ..... ... ..... ... 17 Table 4: ABWR Pipe Insulation Debris Load ............................................................... 18 Table 5: ABWR Other Debris Sources ........................................................................ 18 Table 6: System Flow Conditions ................. ........................................... ........... .. ....... 19 Table 7: Total Clean Strainer Head Loss ..... ............................................................... 23 Table 8: Non-Fibrous Debris Bump-Up Factor ........ ... ......... ... .. ..... .. ....... ..... ......... .... .. . 25 Table 9: RMI Head Lo~s ... .......... ............ .. .... ... ........... ....... ..... .... .. ... ..... ....... . .J. ............ 27 Table 10: Summary of Data ................ ......... .... .. ................................................ .... ..... 28 Table A-1: ECCS Mode, Mission Time and Description ... ... .. .... .. ... .. ...... .... .... ... ... ...... .. 38 Table A-2: ABWR Debris Source Term .... ........ ............. ........ ....................................... 40 Table A-3: ABWR Debris Downstream Concentration ....... ...... ..... ......... ........ ...... .... .... 45 Table A-4: ECCS Suction Strainer Downstream Effects-RHR Core Cooling Mode A 1 49 Table A-5: ECCS Suction Strainer Downstream Effects-RHR Suppression Pool Cooling Mode 81 ..................................................... .................................................................. 62 Table A-6: ECCS Suction Strainer Downstream Effects-Containment Spray with Heat Removal Mode E ... .......................................................... ........ ............ ... ... ... ..... .... ...... . 73 Table A-7: ECCS Suction Strainer Downstream Effects-High Pressure Core Flooder Mode 81 ....... .... ...... .. ....... ..................................................... .............. .. ............. ..... .. ...... .. ... ... 85 Table A-8: ECCS Suction Strainer Downstream Effects-Reactor Core Isolation Cooling System Mode C ... ... .... ....... ....... ...... ................ ........... ........ ....... .. ...... .... ... ............. ........ 95 GEH Public I Page 6 of 105
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1.0 INTRODUCTION
1.1 Background The Advanced Boiling Water Reactor (ABWR) design was certified as 10 CFR Part 52 ,
Appendix A, in a final rulemaking published May 12, 1997, effective June 11 , 1997. In the certified design , emergency core cooling system (ECCS) suction strainers were included to address concerns with debris that could block the suction of the ECCS pumps when reci rcu lating from the suppression pool.
On December 7, 2010, GEH applied to the U.S. Nuclear Regulatory Commission (NRG) for the renewal of the ABWR standard plant design certification (DC), which the NRG had issued on June 11 , 1997. Because of lessons learned from BWR operating experience and from the review of Generic Safety lssue-191 , Assessment of [Effect of] Debris Accumulation on PWR Sump Performance, the staff determined that additional information was required to evaluate compliance of the Emergency Core Cooling System (ECCS) design with 10 CFR 50.46(b)(5). Lessons learned included recognition of the inadequacy of the criterion to allow 50 percent blockage of the strainer surface area and recognition of chemical precipitates as a potential debris source. The staff incorporated these and other lessons learned into revisions of Regulatory Guide (RG) 1.82, Water Sources for Long-Term Recirculation Cooling Following a Loss-of-Coolant Accident.
In a July 20 , 2012 response to GEH's application for certification renewal , the NRG communicated the list of design changes that the NRG considered to be regulatory improvement or changes that could meet the 10 CFR 52.59(b) criteria . Item 9 requested that GEH confirm that the emergency core cooling system suction strainer design complies with 10 CFR 50.46(b)(5), including providing net positive suction head (NPSH) margins using RG 1.82, Revision 4, addressing chemical , in-vessel , and ex-vessel downstream effects, providing a structural analysis, and updating the ITAAC as necessary consistent with the new guidance.
ECCS Suction Strainer Debris Issue Boiling Water Reactor (BWR) strainer performance issues were evaluated in the mid-1990s after some incidents at foreign and domestic BWRs led to concerns about strainer performance. Evaluation of these issues led to enlargement of strainer size, and the N RC's conclusion almost a decade ago that the questions regarding BWR strainer performance had been resolved . In 2007, the NRG did a preliminary area-by-area comparison of regulatory and technical treatment of BWRs vs. PWRs. The NRC's initial conclusion was that there were disparities in treatment, but there is not enough information to validate the GEH Public I Page 7 of 105
NED0-33878 Revision 3 Non-Proprietary Information - Class I (Public) issues or their significance. The NRC concluded additional evaluations were needed to determine the safety significance of these issues.
The NRC's Office of Nuclear Regulatory Research and the BWR Owners' Group (BWROG) have begun new work on BWR strainer performance. The NRC and the BWR Owners Group have met on several occasions to discuss a path forward. The NRC staff has provided perspective to the BWROG on some of the subject areas related to strainer performance based on lessons learned from evaluations of PWR Sump Performance.
Currently operating BWR strainer designs are based on guidance from sources such as the BWR Owners Group Utility Resolution Guidance, the accompanying safety evaluation (SE) and NUREG/CR-6224, Parametric Study of the Potential for BWR ECCS Strainer Blockage Due to LOCA Generated Debris. In future evaluations, BWR strainer designs consider subsequent guidance developed during the resolution of GSl-191 and GL 2004-02 including chemical and downstream effects and strainer head loss and vortexing.
ABWR Solution The ABWR ECCS strainers are sized to conform with the guidelines provided in Reg Guide 1.82 Rev. 4, for the most severe of all postulated breaks.
- The debris generation model was developed in accordance with the Utility Resolution Guidance, NED0-326~6-A (Reference 1).
- The design debris load transported to the suppression pool is based on the Utility Resolution Guidance, NED0-32686-A (Reference 1).
- The ECCS Strainer design is based on the Debris Load Fraction that accumulates on a given strainer for the Loss of Coolant Accident (LOCA) case considered. For conservatism, the worst-case load fraction for each system was applied even if it resulted from a different type of LOCA (RHR vs. MS break).
- Suction strainer sizing criteria is based on meeting NPSH requirements at runout system flow.
The ABWR design provides reasonable assurance that downstream effects as a result of debris bypassing the strainers will not have a deleterious effect on critical components such as fuel rods, valves and pumps downstream of the suction strainers.
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The ABWR design incorporated improvements from the currently operating boiling water reactor (BWR) design:
- ABWR design eliminates recirculation piping external to the reactor pressure vessel (RPV), which removes a significant source of insulation debris and reduces the likelihood of a large high energy pipe break leading to the introduction of debris.
- ABWR main steam and feedwater piping connects to the RPV above the core , thus eliminating a large break loss of coolant accident (LOCA) below the top of active fuel.
- ABWR uses a stainless-steel liner for the submerged portion of the ABWR suppression pool as opposed to carbon steel used in earlier designs of BWR suppression pools, significantly lowering the amount of corrosion products which can accumulate in the suppression pool.
- The use of several materials in the primary containment are prohibited or minimized (e.g., aluminum, zinc), mitigating many of the chemical effects from debris.
- The ABWR has diversification of ECCS delivery points, which helps to reduce the consequences of downstream blockage. Two High Pressure Core Flooder (HPCF) loops deliver coolant to the region above the core (i.e., at the outlet of the fuel assemblies). One of three LPCF loops provide coolant through one of the feed water lines. The Reactor Core Isolation Cooling (RCIC) system delivers coolant to the other feedwater line. Two LPCF systems deliver coolant through separate spargers into the outer annulus region. Should any blockage occur in the lower core region (such as the fuel inlet) which could limit the effectiveness of systems like Residual Heat Removal (RHR)), the HPCF system will still be effective at providing cooling water because it delivers water through spargers located above the core.
1.2 Purpose The purpose of this technical report is to provide certain supporting technical information regarding the new design of the ECCS suction strainers for the ABWR.
This technical report provides supporting information to show conformance with RG 1.82, Water Sources for Long-Term Recirculation Cooling Following a Loss-of-Coolant Accident, Revision 4.
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NED0-33878 Revision 3 Non-Proprietary Information - Class I (Public) 1.3 Acronyms I Acronym I Explanation ABWR Advanced Boiling Water Reactor OBA Design Basis Accident DCD Design Control Document ECCS Emergency Core Cooling System ESBWR Economic Simplified Boiling Water Reactor FAPCS Fuel and Auxiliary Pools Cooling System GPM Gallons per Minute HPCF High Pressure Core Flooder IOZ Inorganic Zinc LOCA Loss of Coolant Accident MSL Main Steam Line NPSH Net Positive Suction Head RCIC Reactor Core Isolation Cooling RHR Residual Heat Removal RM I Reflective Metal Insulation GEH Public IPage 10 of 105
NED0-33878 Revision 3 Non-Proprietary Information - Class I (Publ ic) 1.4 Definitions To understand certa in design term s or supporting information, definition s are provided below.
Term Descri~tion Units D Outside strainer diameter ft L Strainer length ft Ac Circumscribed strainer area ft2 AFoiI Foil Area on Strainer ft2 Q Flow rate gpm T water temperature F
µ Dynamic viscosity lbm-sec/ft 2 V Kinematic viscosity ft 2/sec I
Ah Head loss ftH20 L.\hTotal Total strainer head loss ftH20 L.\hc1ean Losses through a clean strainer ftH20 Losses due to Reflective Metal Insulation L.\hRMI ftH20 (RMI) on strainer Kc1ean Clean strainer head loss coefficient ftH20 Kh Debris head loss coefficient -
Kbu Bump up factor for non-fibrous debris -
Kp Proportionality Constant -
Kt Thickness constant for RMI material -
I I
K2 Strainer flange resistance coefficient -
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Term Descri12tion Units u Circumscribed approach velocity ft/sec Approach velocity corrected for strainer U1 ft/sec surface area Us Average RMI settling velocity ft/sec V Flow velocity in suction line ft/sec MF Mass of fibrous debris lbm Mc Mass of sludge I corrosion products lbm Mz Mass of inorganic zinc (IOZ) lbm Mpc Mass of epoxy coated IOZ (paint chips) lbm MRF Mass of rust flakes lbm Meo Mass of dust I dirt lbm d IInterfiber distance ft I dr Fiber diameter ft t Debris bed thickness ft ta Theoretical RMI Bed Thickness ft tp Projected RMI Bed Thickness ft tmax Max RMI Bed Thickness ft GEH Public IPage 12 of 105
NED0-33878 Revision 3 Non-Proprietary Information - Class I (Public) 1.5. Assumptions 1.5.1 Some design details from (( )) which are used as inputs to this evaluation, are considered representative of the ABWR standard plant.
Examples include:
- The pipe insulation debris load calculation (Reference 7).
- The NPSH calculations given in References 17, 18, and 19.
1.5.2 For the purpose of estimating viscosity for head loss through the strainer, the suppression pool temperature is assumed to be ([
))
1.5.3 (( )) the best estimate head loss predictions obtained with the methodology described in Reference 5 will provide reasonable assurance of producing a bounding head loss estimate.
1.5.4 It is assumed that a design basis sludge load of 200 lbm per cycle bounds the generation rate for a typical ABWR.
Section 3.2.4.3.2 of the URG (Reference 1), describes a survey of operating BWRs that measured the rate lof sludge generation . The data, collected from 12 plants with Mark I, II , and Ill containment designs, indicated a median sludge generation rate of 88 lbm per year. The URG recommends a value of 150 lbm per year to bound these results unless a lower plant-specific value can be justified .
The ABWR design features many improvements over the conventional BWRs that will help to minimize the generation of sludge. Specifically, the suppression pool is equipped with a stainless steel liner, and many interfacing systems utilize stainless steel pipe, which reduces the generation of carbon steel corrosion products. The ABWR suppression pool is enclosed in a concrete compartment and protected from the drywell environment, unlike some containment designs (from the BWROG survey), which are subject to dirt and debris falling through grating into the pool.
The above considerations suggest the ABWR sludge generation rate would be less than the typical operating BWR. Therefore, the assumed ABWR sludge load of 200 lbm ( 100 lbm per year with a two-year operating cycle) is considered a reasonable assumption . Furthermore, there is a COL Item in Section 6.2.7.3 of the ABWR Design Control Document (DCD) (Reference 21) that requires the applicant to establish a method for maintaining a level of cleanliness that supports this assumption.
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1.5.5 It is assumed that a surface-area-to-volume ratio of (( )) for RMI debris. ((
)), Table 1 below, ((
))
Table 1: RMI Surface Area to Volume Ratio Values Taken Explicitly from Table 3 of Derived to support this Reference 15 assumption RMI Surface Volume of RMI Area ((
Pipe Radial RMI RMI (( Surface Area to OD Thickness OD Volume Ratio
))
))
in in in in 2 in 3 -
((
I ))
RMIOD
(( ))
This assumption is used .in Section 2.1.3.5 for the purpose of estimating the contributions of RMI debris to the strainer head loss.
1.5.6 The suppression pool, at its minimum drawdown level , provides a static head of
(( )) above the pump inlet nozzle. This amount of static head is consistent with the static head used in (( )) calculation 31113-0E11-2113 I
(Reference 17).
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NED0-33878 Revision 3 Non-Proprietary Information - Class I (Public) 2.0 DESIGN METHODS The methodology for sizing and qualifying a stacked disk ECCS Suction Strainer was initially developed in Reference 2. After this guidance was issued , it was determined that the methodology contained certain flaws, which are addressed in Reference 3. An updated method was documented in Reference 5, and was implemented for the Economic Simplified Boiling Water Reactor (ESBWR) Fuel and Auxiliary Pools Cooling System (FAPCS) strainer in Reference 12. These references are used as the model for this ABWR evaluation.
For simplicity, an existing strainer design will be selected from those evaluated in Reference 5. The ABWR-specific debris load , flow rate , and pool conditions will then be applied using the methods described in Reference 5 to demonstrate that a qualified strainer design exists to support ABWR certification . Note that this evaluation demonstrates a single bounding design for the ABWR standard design to ensure compliance to 10CFR50.46(b)(5).
Future COLA applicants or COL licensees that elect to develop a more optimal sizing for each of the three ECCS strainers would need to seek NRC approval of a departure to the ABWR standard design for the strainers, which would require review and approval by the NRC as part of the COLA or in a post-COL license amendment request.
I 2.1 Discussion This section describes the strainer qualification process, and the reasoning for each step .
2.1 .1 Debris Types / Quantities This subsection discusses the types and quantities of debris in the ABWR standard design.
2.1.1.1 Piping Insulation The debris generated from pipe insulation for (( )) was calculated in 31113-0A51-2104 Rev. 0, which can be found in (( )).
This calculation is based on Method 3 of Reference 1, which uses spherical zones of influence with a volume based on destruction pressure specific to the type of insulation .
This calculation evaluates Nukon fiber debris and reflective metal insulation (RMI) debris under two scenarios: (1) a Main Steam Line (MSL) break, and (2) a break in the Residual Heat Removal System (RHR). These two cases were selected because:
- A MSL break has the largest ZOI and generates the most debris of any break.
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- Although an RHR break generates less debris than a MSL break, there is no personnel grating separating the RHR break from the drywell to wetwell connecting vents. Therefore, a larger fraction of generated debris could make its way to the wetwell, whereas some higher-elevation MSL-generated debris would be intercepted by the grating. Until these transport factors are considered, the RHR break should not be ruled out.
- Although the ZOI for an RHR break is slightly smaller than that of a Feedwater break, the amount of debris generated is slightly greater - presumably because there is more insulated pipe in close proximity to RHR piping than is the case for Feedwater piping .
- Also, a break in RHR piping results in a different combination of ECCS systems to mitigate the event compared to a MSL break. Thus, certain systems may have a higher debris load fraction for an RHR break than they would for a MSL break.
Additional discussion is provided in (( )). The basis described above was used to generate the debris values found in Section 4.3 .1.6.1 of the (( )). The values were updated for Rev. 1 of that specification to those shown below:
Table 2: (( )) Pipe Insulation Debris Load NUKON I RMI Break Type above I below grating above I below grating
((
))
The basis for the values in Table 2 is discussed in ((
)) . This discussion explains that the original insulation quantities were updated based on the restrictions for Nukon to small bore piping and, also, to include tra nsport factors have been included in the derivation of these numbers. Because tra nsport has already been considered, there is no longer a reason to distinguish the debris above the grating from debris below the gdting. The numbers represent the quantity of GEH Public IPage 16 of 105
NED0-33878 Revision 3 Non-Proprietary Information - Class I (Public) debris that has already made its way to the suppression pool. Therefore, the details related to the grating have been removed as they are no longer pertinent.
Because the MSL break deposits a much greater amount of debris in the suppression pool than RHR break, the only remaining reason to consider an RHR break is the difference in debris load fractions (fourth bullet from above). This evaluation can be simplified by assuming a MSL break (maximum debris) along with the maximum debris load fractions reported in Reference 9 (even though some may correspond to an RHR break).
Table 3: ABWR Debris Load Fractions Debris Load Fraction
((
))
I As shown in Table 3, the E11 and E22 load fractions of (( )), respectively, are based on the combined flow of one HPCF and dne RHR loop at rated flow following a break in one of the three RHR loops (with no operation of RCIC). In a more realistic scenario, the two remaining RHR loops would be running in parallel and HPCF would be drawing from the CST. But because this results in no debris load on the HPCF strainer, and a load fraction of only 0.5 split between the two RHR strainers, the alignment described above is more conservative.
The E51 load fraction of (( )) is based on the combined flow of one RHR, one HPCF, and one RCIC loop at rated flow following a break in one of the three RHR loops. In a more realistic scenario, given the large size of an RHR break, the RCIC system would not be credited in the overall ECCS performance. RCIC performance is credited in medium and small break LOCAs, which would have correspondingly less debris generated.
Therefore, the load fraction assumed above is conservative.
With this justification, the RHR debris generation values will be ignored in favor of the MSL values.
Lastly, it was recommended in Volume 1, page 59, of Reference 7, that an additional 1 ft 3 of fi brous debris be added to account for miscellaneous foreign material left in GEH Public
NED0-33878 Revision 3 Non-Proprietary Information - Class I (Public) containment. This will be factored into the calculation as if it were Nukon insulation.
Therefore, the (( )) of Nukon resulting from a MSL break is increased by 1 ft3 3
(0 .028 m ) to give the following finalized piping insulation values:
Table 4: ABWR Pipe Insulation Debris Load NUKON RMI
(( ))
The total Nukon volume of (( )) can be converted to a Total Fibrous Debris Mass (MF) on a density of 2.4 lbm/ft3 (per Section 6.3.3 of Reference 11 ).
MF= (( ))
2.1 .1.2 Debris from Other Sources The debris generated from other sources was determined in accordance with Reference 11 , making conservative assumptions where appropriate. The values below are taken from Section 4.3.1.6.2 in Revision 1 of Reference 8 and related discussion can be found in Volume 1, pages 58-59 of Reference 7. The "Mx' designations for debris type are used later in his evaluation, as are the ratios in the third column. I Table 5: ABWR Other Debris Sources
((
Debris Type Strainer Load 11 Mc= Sludge/ corrosion prod. 200 lbm ((
Mz =Inorganic Zinc (IOZ) 47 lbm I
MPc =Epoxy Coated IOZ 85 lbm MRF =Rust Flakes 50 lbm Meo =Dust / Dirt 150 lbm ))
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NED0-33878 Revision 3 Non-Proprietary Information - Class I (Public) 2.1.2 Selection of Bounding Strainer Design The flow rate through the strainer is assumed to be equivalent to the runout flow for the corresponding ECCS pump. These flows are taken from Reference 9:
Table 6: System Flow Conditions
((
))
The pool water temperature is assumed to be at (( )) per Assumption 1.5.2.
A range of qualified stacked disk strainers from the operating fleet is given in Reference 6.
To simplify this evaluation, the (( )) strainer (Reference 16) is used to evaluate applicability to the ABWR RHR System. It is understood that the ((
)) RHR ~ystem flow (( )) is substantially hi~her than the ABWR RHR flow rate reported above, and therefore may be oversized for the application . This is conservative for the safety function the strainer performs, but may not be the most practical or economical choice. If future COLA applicants or COL licensees elect to seek NRC approval of a departure from the standard design , future design work can be performed to qualify a more optimized strainer size, as discussed in Section 2.0 above, following the process described herein .
Because the E22 and E51 strainers have lower flow rates and lower debris load factors than the E11 strainer, it is assumed that their performance is bounded by the evaluation of the E11 system . Therefore, the head loss evaluation will be performed for only the E11 .
In Section 3.0, a check is performed against the NPSH requirements for each of the three ECCS systems. As with E11 , future work can determine a more optimal size for the E22 and E51 strainers.
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NED0-33878 Revision 3 Non-Proprietary Information - Class I (Public) 2.1.3 Head Loss Evaluation The head loss correlation given by Reference 2 is defined as:
((
))
See Section 1.4 for a definition of these variables. Some additional factors will be added to this correlation to address considerations such as RMI insulation . The content of this section will explain the derivation of each of these parameters, and the final correlation is summarized in Section 3.
The first term from the above equation represents the losses through a clean strainer.
((
)).
The second term accounts for losses due to debris accumulation on the strainer (excluding RM I). ((
)).
2.1.3.1 Spreadsheet Instructions Reference 5 contains instructions on how to use a spreadsheet template (verified in Reference 6) to simplify many of the calculations related to strainer dimensions and debris bed thickness. The spreadsheet contains data in the "Stats All" tab for strainer designs that have already been qualified , and leaves a blank column (Column R) for a new design to be added . ((
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)) Some of these rows are not applicable to the updated method discussed in Reference 5. Others are applicable to the updated method but require more explanation and are, therefore, discussed in more detail in the following sections.
2.1.3.2 Losses through Clean Strainer and Flange The losses through the clean strainer are easily derived based on the value ((
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))
A similar method is used to determine the losses through the connecting flange. ((
))
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Table 7: Total Clean Strainer Head Loss Clean Strainer Losses ((
((
)) ))
2.1.3.3 Debris Load Head Loss Coefficient (Kh)
The definition of Kh, is based upon the method of Reference 2 with modifications described by Reference 3. The new Kh correlation makes a distinction between two strainer loading scenarios. ((
)) The head loss coefficient is calculated to be:
((
))
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NED0-33878 Revision 3 Non-Proprietary Information - Class I (Public) 2.1 .3.4 Strainer Debris Load Bump-up Factor (Kbu)
The methodology described in Reference 2 includes (near the end of Section 3.3) a bump-up factor to account for the presence of non-fibrous components of the debris bed. The factor is defined in Appendix A of Reference 13. Table 8 summarizes the results of each step and provides a basis for the values used .
Append ix A of Reference 13 was originally intended to derive the head loss coefficient Kh.
But because this evaluation uses an alternate method to derive Kh, many of the steps below are simply marked "not required". Only the steps needed to derive K bu are used .
((
))
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Table 8: Non-Fibrous Debris Bump-Up Factor Step Variable Value Units Basis Circumscribed Strainer Area
(( ft2 1 (Ac) Row 19 of Ref. 6 2 Strainer Approach Velocity (U) ft/sec Row 52 of Ref. 6 3 Mass of fibrous debris (MF)* lbm Section 2.1.1.1 Mass of corrosion products 3 (Mc) lbm Table 5 3 Mc/MF - Table 5 4-8 Not Required Mass ratios for other debris 9 - Table 5 10 l"a" coefficient for all debris - Ref. ~ 3 Appendix A 10 "b" coefficient for all debris - Ref. 13 Appendix A "a" coefficient for fiber/ sludge 10 only - Ref. 13 Appendix A "b" coefficient for fiber/ sludge 10 only - Ref. 13 Appendix A 11 K bu )) - Ref. 13 Appendix A
- The load factor is not applied in this table, because K bu is simply a ratio of non-fi brous to fi brous debris.
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NED0-33878 Revision 3 Non-Proprietary Information - Class I (Public) 2.1.3.5 RMI Insulation Losses The contribution of RMI type insulation to the overall strainer head loss is small compared to that of other types of debris. The methodology for estimating the RMI head loss is given in Appendix B of Reference 13. Table 9 summarizes the results of each step and provides a basis for the values used.
Note that the debris table in Reference 8 specifies that RMI is stainless steel foil ((
))
For additional conservatism, this entire amount is assumed to collect entirely on one strainer (ire., the debris load factor is not applied).
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Table 9: RMI Head Loss Step Variable Value Units Basis
- RMI Type (( - Section 2.1.3.5
- RMI Thickness in Reference 8
- Strainer Length (L) ft Row 8 of Ref. 6
- Strainer Outer Diameter (D) ft Row 9 of Ref. 6
- Maximum Flow Rate (Q) GPM Table 6
- Foil Area on Strainer (AFoi1) ft2 Section 2.1.3.5 Circumscribed Strainer Area 1 ft2 Row 19 of Ref. 6 (Ac)
Strainer Approach Velocity 2 ft/sec Row 52 of Ref. 6 (U)
Average RMI Settli ng 3 ft/sec Table B-1 of Ref. 13*
Velocity (Us) 1 Max RMI Bed Thickness 3 ft Appendix B of Ref. 13 (tmax)
Empirical Thickness 4 ft Table B-2 of Ref. 13*
Constant (Ki)
Theoretical Bed Thickness 4 ft Appendix B of Ref. 13 (ta) 5 Projected Bed Thickness (tp) ft Appendix B of Ref. 13 6 Proportionality Constant (Kp) Table B-3 of Ref. 13*
6 Head Loss (b.h) for RMI )) ft Appendix B of Ref. 13
- ((
))
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NED0-33878 Revision 3 Non-Proprietary Information - Class I (Public) 3.0 DESIGN RESULTS & ACCEPTANCE CRITERIA 3.1 Design Results The head loss is calculated by compiling all the factors discussed in Section 2.1.3. The total head loss equation has been updated as shown to include various conservative factors and assumptions described in previous sections ((
))
Table 10 below summarizes each value and where in this report it was derived.
Table 10: Summary of Data Variable Value Units Basis
((
I I
... ))
The total RHR strainer head is calculated as follows ((
))
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NED0-33878 Revision 3 Non-Proprietary Information - Class I (Public) 3.1 .1 RHR Acceptance Criteria The required NPSH for the RHR pumps is given in DCD Table 6.3-9 (Reference 21) as 2.4 m (7.9 ft). According to a (( )) calculation (( )), there is an available NPSH of (( )), assuming the strainer losses do not exceed ((
)).
((
)) the strainer losses calculated in this evaluation can be adjusted based on water viscosity. ((
))
This adjustment shows that the strainer design from this evaluation can satisfy the NPSH req uirements of the RHR system of a typical ABWR.
3.1 .2 HPCF Acceptancb Criteria The required NPSH for the HPCF pumps is given in DCD Table 6.3-8 (Reference 21) as 2.2 m (7.2 ft). According to a (( )) calculation (( )) , the HPCF system provides an available NPSH of (( )), assuming that the maximum strainer losses are limited to (( )) of head given a temperature of 100°C and a runout flow of 890 m3/hr.
The results shown in Section 3.1 meet the (( )) of head required by (( )).
There is significant conservatism in this method, because the NPSH margin for the
(( )) HPCF system was determined at a lower flow rate and viscosity.
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NED0-33878 Revision 3 Non-Proprietary Information - Class I (Public) 3.1 .3 RCIC Acceptance Criteria The required NPSH for the RCIC pumps is given in DCD Table 5.4-2 (Reference 20) as 7.3 m (24.0 ft). According to a (( )) calculation (( )), the RCIC system provides an available NPSH of (( )), assuming that the maximum strainer losses are limited to (( )) of head given a temperature of 77°C and a runout flow of 199 m 3/hr.
The results shown in Section 3.1 meet the (( )) of head required by (( )) .
There is significant conservatism in this method, because the NPSH margin for the
(( )) RCIC system was determined at a lower flow rate and viscosity.
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4.0 CONCLUSION
S It has been shown that a strainer design exists that can be applied to the RHR System for the ABWR such that under the most limiting debris load and environmental conditions, the head losses across the debris bed, strainer, and pipe flange shall be limited to ((
)) of water under the conservative assumptions of pump runout flow and higher viscosities resulting from an assumed low temperature of (( )). This low temperature assumption was not credited when calculating NPSH margin .
This bounding strainer design was shown to also satisfy the NPSH requirements for the HPCF and RCIC pumps.
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5.0 REFERENCES
- 1. NED0-32686-A Rev. 0, Utility Resolution Guidance for ECCS Suction Strainer Blockage, November 1996
- 2. NEDC-32721 P-A Rev. 2, Licensing Topical Report: Application Methodology for the GE Stacked Disk ECCS Suction Strainer, March 2003 (GEH Proprietary)
- 3. PLM Object 0000-0080-3041 Rev. 0, Evaluation Report (GEH Proprietary)
- 4. PLM Object 002N1768 Rev. 1, Closure Letter (GEH Proprietary)
- 5. PLM Object 0000-0080-3039 Rev. 2, Plant Summary Design Notes FINAL.pdf (GEH Proprietary)
- 6. PLM Object 0000-0081-1211 Rev. 2, USBWR Strainer Stats20080520.xls (GEH Proprietary)
- 7. PLM Object A60-00051-00, Design Record File for Suppression Pool Suction Strainers (GEH Proprietary)
I 8. 31113.62 .3031, Suppression Pool Strainer f[ [ ))
(GEH Proprietary)
- 9. 31113.62.3031-01600 Rev. 1, Suppression Pool Suction Strainer ((
)) (GEH Proprietary)
- 10. 31113-0U71-1000 Rev. 3, (( )) Reactor Building Design Specification (GEH Proprietary)
- 11. NUREG/CR-6224 (SEA No. 93-554-06-A:1), Parametric Study of the Potential for BWR ECCS Strainer Blockage Due to LOCA Generated Debris, October 1995
- 12. PLM Object 0000-0092-3114 Rev. 1, Preliminary Sizing of FAPCS Strainer (GEH Proprietary)
- 13. Continuum Dynamics Report 95-09, Testing of Alternate Strainers with Insulation Fiber and Other Debris, November 1996 GEH Public IPage 32 of 105
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- 14. NEDM-20363-13-01, Hydraulics of Boiling Water Reactors, August 2006
- 15. Continuum Dynamics Report 95-17, Structural Properties of Reflective Metal Insulation Installed in U.S. BWR's, 1996
- 16. 105E2586 Rev. 4, Assembly Drawing Suction Strainer, RHR, (( ))
- 17. 31113-0E11-2113 Rev. 1, (( )) Residual Heat Removal System - Pump NPSH Calculation (GEH Proprietary)
- 18. 31113-0E22-2105 Rev. 1, High Pressure Core Flooder System - Pump NPSH Calculation (GEH Proprietary)
- 19. 31113-0E51-2121 Rev. 0, (( )) Reactor Core Isolation Cooling System -
Pump NPSH Calculation (GEH Proprietary)
- 20. 25A5675AG Rev. 6, ABWR Design Control Document, Tier 2, Chapter 5
- 21. 25A5675AH Rev. 6, ABWR Design Control Document, Tier 2, Chapter 6
- 22. 25A5675BB Rev. 6, ABWR Design Control Document, Tier 2, Chapter 21
- 23. f NED0-32686-A, Utility Resolution Guide for ECt S Suction Strainer Blockage Volume 4 Technical Support Documentation [GE-NE-T23-00700-15-21 March 1996 (Rev. 1) Evaluation of the Effects of Debris on ECCS Performance]
- 24. 31113-1 E11-M2001 through M2010, Piping and Instrument Diagram Residual Heat Removal System (GEH Proprietary)
- 25. 31113-1 E22-M2001 and M2002, Piping and Instrument Diagram HP Core Flooder System (GEH Proprietary)
- 26. 31113-1 E51-M2001 through M2003, Piping and Instrument Diagram Reactor Core Isolation Cooling System (GEH Proprietary)
- 28. 31113-1E11-M0100, Rev 9, Residual Heat Removal System Design List (GEH Proprietary)
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- 30. 31113-1E51-M0100, Reactor Core Isolation Cooling System Design List (GEH Proprietary)
- 31. 31113-1N22-M0100, Feedwater System Design List (GEH Proprietary) 32 . 31113-0E11-2010, Rev.4, Residual Heat Removal (RHR) System Design Description (GEH Proprietary)
- 33. 31113-0E22-2010, Rev.5, High Pressure Core Flooder System Design Description (GEH Proprietary)
- 34. 31113-0E51-2010, Rev. 5, Reactor Core Isolation Cooling System (RCIC) Design Description (GEH Proprietary) 35 . NEDC-32976P, SAFER/GESTR-LOCA Loss of Coolant Accident Analysis
(( )) (GEH Proprietary)
- 36. 105E2763 R3 , HPCF Sparger (GEH Proprietary)
- 37. NEI 04i 07 Rev 0, Pressurized Water Reactor Sump Perforrriance Methodology
- 38. NUREG/CR-6808 (LA-UR-03-0880), Knowledge Base for the Effect of Debris on Pressurized Water Reactor Emergency Core Cooling Sump Performance, February 2003
- 39. NEDC-33302P, Fiber Insulation Effects with Defender Lower Tie Plate, March 2007 (GNF Proprietary)
- 40. ASME QME-1-2007, Qualification of Active Mechanical Equipment Used in Nuclear Power Plants
- 41. Regulatory Guide 1.100, Rev. 3, Seismic Qualification of Electrical and Active Mechanical Equipment and Functional Qualification of Active Mechanical Equipment for Nuclear Power Plants
- 42. 31113-0A23-1000, (( )) Project Design Manual, Rev 36, 6/19/2014 (GEH Proprietary)
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APPENDIX A DOWNSTREAM EFFECTS EVALUATION A.1 OVERVIEW Evaluation of the ABWR containment includes a review of the flow paths downstream of the emergency core cooling systems (ECCS). The concerns addressed for downstream effects are:
- Blockage of flow paths in equipment; for example, spray nozzles or tight-clearance valves
- Wear and abrasion of surfaces; for example, pump running surfaces, heat exchanger tubes and orifices
- Blockage of flow clearances through fuel assemblies In general, the downstream review broadly considers flow blockage in the ECCS flow paths, as well as examining wear and abrasion in systems, structures, and components in the ECCS flow paths that are credited for long-term cooling functions.
The downstream review considers the flow clearance through the ECCS suction strainer.
This determines the maximum size of particulate debris that will pass through the suction strainer and enter tf e ECCS flow paths. If passages and channelsj in the ECCS downstream of the suction strainer are larger than the flow clearance thro gh the suction strainer, blockage of those passages and channels by ingested debris is not a concern. If there are passages and channels equal to or smaller than the flow clearance through the suction strainer, then the potential for blockage exists and an evaluation is made to determine if the consequences of blockage are acceptable or if additional evaluation or enhancements are warranted.
Similarly, wear and abrasion of surfaces in the ECCS is evaluated, based on the flow rates to which the surfaces will be subjected and the grittiness or abrasiveness of the ingested debris. The abrasiveness of the debris is plant-specific and depends on the insulation materials that become debris. For example, fiberglass is known to be an abrasive material.
The detailed ABWR ECCS downstream effects evaluation is documented in Appendix A, Tables A-4 through A-8.
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A.2 ECCS SYSTEM DESCRIPTIONS AND MISSION TIMES The downstream review defines both long-term and short-term system operating lineups, conditions of operation, and mission times (see Table A-1 ). Where more than one ECCS configuration is used during long-term and short-term operation, each lineup is evaluated with respect to downstream effects. The definition of the mission times form the premise from which the short- and long-term consequences are determined and evaluated.
Once conditions of operation and mission times are established, downstream process fluid conditions are defined, including assumed fiber content, hard materials, soft materials, and various sizes of material particulates. It can be shown that particles larger than the sump-screen mesh size will not pass through to downstream components. Debris may pass through because of its aspect ratio or because it is "soft" and differential pressure across the screen pulls it through the mesh. No credit is taken for thin-bed filtering effects.
See Figure A-1 below illustrating ECCS flow paths.
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Steam Feedwater FIGURE A-1, ABWR ECCS FLOW PATHS GEH Public IPage 37 of 105
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Table A-1: ECCS Mode, Mission Time and Description Emergency Mode of Mission Time Description Cool Cooling Operation System I I RHR CORE (( 30 days ((
COOLING RHR 30 days SUPPRESSION POOL COOLING RHR 30 days WElWELL SPRAY I I I
HIGH DI PRE SSURE CORE FLOODER REACTOR 12 hrs CORE ISOLATION COOLING SYSTEM RHR Alternate Based on Flow path (not fire water credited) )) tank I diesel fire pump fuel capacity
))
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A.3 DEBRIS INGESTION A summary of the debris ingestion model used to assess the equipment in the ECCS systems is provided below in Table A-2, ABWR Debris Source Term. The debris considered includes fibrous insulation debris and particulate debris consisting of paint chips, concrete dust, and reflective metallic insulation shards small enough to pass through the holes of the ECCS suction strainer perforated plates.
For passive screens the amount of debris, both fibrous and particulate, that passes through the screen is dependent upon the size of the flow passages in the suction strainer and the ratio of the open area of the screen to the closed area of the screen. There are other factors affecting debris bypass through the suction strainer, such as the fluid approach velocity to the screen, and the screen geometry.
The ABWR suction strainer perforated discs are fabricated from 11 gauge (0.12 in.) thick stainless steel plate with 0.125 in. diameter holes with 0.188 in. staggered spacing (Reference 16).
A series of assumptions has been applied in determining the make-up of the post-LOCA fluid :
- 1. No credit is provided for filtering of material due to a thin bed of material on the suction strainer
- 2. The dimensions of particulates p1ssing through a suction strainer are assumed as follows:
The maximum length (I) of deformable particulates that may pass through the penetrations (holes) in passive suction strainers is equal to ((
))
The maximum width (w) of deformable particulates that may pass through the penetrations (holes) in passive suction strainers is equal to ((
))
The maximum thickness (t) of deformable particulates that may pass through the penetrations (holes) in a passive suction strainers is equal to ((
))
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The maximum cross-sectional area (a) of deformable particulates that may pass through the penetrations (holes) in a passive suction strainer is equal to ((
))
The maximum dimension (length, width, and/or thickness) of non-deformable particulates that may pass through a suction strainer is limited to the cross-sectional flow area of the penetration (hole) in the suction strainer.
Table A-2: ABWR Debris Source Term Debris Type Strainer Load Debris Downstream Strainer Sludge / corrosion prod . 200 lbm 200 lbm Inorganic Zinc (IOZ) 47 lbm 47 lbm Epoxy Coated IOZ 85 lbm 85 lbm Rust Flakes 50 lbm 50 lbm Dust/ Dirt 150 lbm 150 lbm NUKON 51.6 lbm 51.6 lbm Note1 Reflective Metal Insulation 38,500 lbm 38,500 lbm Nole 2
((
))
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A.4 WEAR RATE AND COMPONENT EVALUATION A.4.1 Auxiliary Equipment Evaluation The methodology presented in NEI 04-07, Pressurized Water Reactor Sump Performance Evaluation Methodology (Reference 37), was applied to assess auxiliary components subject to debris-laden post LOCA fluid . The following EGGS modes of operation were assessed for downstream effects. EGGS component sizing was developed from
- TABLE A-4 , RHR CORE COOLING MODE A1 (Ref: 31113-1E11-M2001 through M2010, Piping and Instrument Diagram Residual Heat Removal System (Reference 24) and 31113-1N22-M2001, Piping and Instrument Diagram Feedwater System (GEH Proprietary) (Reference 27))
- TABLE A-5 , RHR SUPPRESSION POOL COOLING MODE B1 (Ref: 31113-1E11 -
M2001 through M2010 , Piping and Instrument Diagram Residual Heat Removal System) (Reference 24)
- TABLE A-6 , RHR CONTAINMENT SPRAY with HEAT REMOVAL MODE E (Ref:
r 1113-1 E11-M2001 through M2010, Piping and lnstrpment Diagram Residual Heat Removal System) (Reference 24)
- TABLEA-7, HIGH PRESSURE CORE FLOODER MODE B1(Ref: 31113-1E22-M2001 and M2002 , Piping and Instrument Diagram HP Core Flooder System)
(Reference 25)
- TABLE A-8 , REACTOR CORE ISOLATION COOLING SYSTEM MODE C
{Ref:31113-1 E51-M2001 through M2003, Piping and Instrument Diagram Reactor Core Isolation Cooling System (Reference 26) and 31113-1 N22-M2001 , Piping and Instrument Diagram Feedwater System (GEH Proprietary) (Reference 27)
NED0-32686-A, Utility Resolution Guide for EGGS Suction Strainer Blockage, Volume 4, Technical Support Documentation [Evaluation of the Effects of Debris on EGGS Performance GE-NE-T23-00700-15-21 March 1996 (Rev. 1)] (Reference 23), provides a generic safety evaluation for EGGS auxiliary components that bounds the EGGS 1
components for ABWR.
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This assessment addresses auxiliary components including ECCS pumps required to operate during recovery from LOCA and containment steam line break accidents. This report is incorporated by reference in the ABWR DCD Tier 2. This report imposes requirements on ABWR design .
The ECCS pumps are assumed to operate for the required mission time of 30 days following a LOCA. The evaluations consider ECCS pump hydraulic performance, mechanical shaft seal assembly performance, and pump mechanical performance (vibration).
NED0-32686-A, Utility Resolution Guide for ECCS Suction Strainer Blockage, Volume 4, Technical Support Documentation [Evaluation of the Effects of Debris on ECCS Performance GE-NE-T23-00700-15-21 March 1996 (Rev. 1)] (Reference 23), provides a generic safety evaluation for ECCS auxiliary components including pumps that bounds the ECCS systems for ABWR.
ECCS pump performance for the specific plant as-built configuration will require demonstration of acceptable performance under design conditions including design debris loading . Demonstration of acceptable performance for as-built ECCS pumps is validated under ASME QME-1-2007, Qualification of Active Mechanical Equipment Used in Nuclear Power Plants (Reference 40), as endorsed by RG 1.100, "Seismic Qualification of Electrical and jActive Mechanical Equipment and Functional Q~alification of Active Mechanical Equipment for Nuclear Power Plants," Revision 3, September 2009 (Reference 41 ).
This assessment addresses the effect of wear on ECCS heat exchangers and evaluate the consequences of wall thinning on heat exchanger performance. A tube plugging evaluation would be required if the heat exchanger tube inner diameter is smaller than the largest expected particle.
This assessment addresses the effect of wear on orifice and spray nozzles in the credited ECCS . An orifice/ nozzle plugging evaluation would be required if the inner diameter is smaller than the largest expected particle.
This assessment addresses the plugging and wear on instrumentation tubing based on instrumentation line configuration and orientation. While debris will tend to tend to settle out in low flow areas in ECCS process piping, guidelines for locating process instrument connections (taps) on main process pipelines with fittings installed above the horizontal plane of the process piping ensures that no settling of debris in an instrument line will occur. Also, pressure instruments measure through impulse piping. There is no flow with this configuration to pull debris into the measuring devices.
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In the Safety Evaluation for WCAP-16406P (ML073520295), the NRC concluded that no settling of debris will occur in an instrument line installed above the horizontal plane of the process piping. The (( )) ABWR Project Design Manual (31113-0A23-1000 ,
Reference 42) provides guidelines for locating process instrument connections (taps) on main process pipelines to ensure that fittings on the bottom of piping where they can collect crud are avoided . Therefore, ECCS instrument lines in service during post-LOCA operation are installed above the horizontal plane of the process piping. No settling of debris in an instrument line in this orientation is expected .
This assessment addresses the effect of wear and plugging on system piping and components based on system flow and material settling velocities. The evaluation reviews areas of localized high velocity and high turbulence.
Thi s assessment addresses the effect of wear and plugging in reactor vessel internals or reactor fuel. See Figure A-2 for the layout of ECCS components.
RG 1.82 Revision 4 states downstream blockage is a concern for tight-clearance valves (such as throttle and check valves) that are not in the fully open position during post-LOCA operation. ECCS components in the flow path in service during post LOCA modes of operation are evaluated from fa ilure due to blockage under design debris loading . Tight clearance valves such as throttle and check valves were reviewed under this evaluation .
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- HPCF RCIC Containment Spray FIGURE A-2, LAYOUT OF ECCS COMPONENTS FOR DOWNSTREAM ASSESSMENT GEH Public I Page 44 of 105
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Table A-3: ABWR Debris Downstream Concentration Concentration In SP ppm by Debris Type Assessment from NED0 -32686 Vol 4 weight [% by vol]
Sludge is a generic term for rust particles from the carbon steel piping Sludge I connected to the suppression pool. Sludge is generated during normal corrosion (( operation when the suppression pool is inaccessible. The sand will not prod.
melt or form a large enough agglomeration to significantly block flow.
Dirt/ Dust is generated during normal operation when the suppression Dust I Dirt pool is inaccessible.
The failure mode for the IOZ could include some small flakes that would very rapidly break up into particles or very small pieces . The Inorganic Zinc size of the very small pieces would probably be much less than 0.060 (IOZ) inches across. The small chips or flakes wou ld result only where the IOZ was disbanded , if such areas existed. A tightly bonded IOZ would erode by powdering and would not flake or chip off the surface.
Rust particles are generated during normal operation when the suppression pool is inaccessible . The rust chips are of low strength Rust Flakes and will fracture into even smaller pieces upon interaction with other components.
Failed epoxy coating would be expected to produce chips or small sheets because epoxies have good tensile strength and are somewhat Epoxy Coated flexible during a LOCA event. The epoxy paint is also relatively brittle IOZ an1 will breakup into smaller pieces upon interaction with other cor ponents .
(1) Assume all NUKON passes through strainer (2) Assume 23% NUKON (fines) pass through strainer The glass fibers are so fragile that they have virtually no mechanical NUKON strength. The rust, paint, and fiberglass debris that pass through the suppression pool strainers will be subjected to the ECCS flow rates and turbulence that will cause disintegration into particles of even smaller sizes.
Reflective (1) Assume all RMI passes through strainer Metal (2) Assume 4.3% RM I small pieces pass through strainer Insulation (1) Assume non-fiber debris contributes to wear/erosion with all RMI passing through strainer Total Non- (2) Assume non-fiber debris contributes to wear/erosion with Fiber Debris 4.3% RMI passing through strainer Concentration
)) Experimental data on effects of particulates on pump hydraulic performance applied to ECCS type pumps show that pump performance degradation is negligible for particulate concentrations less than 1% by volume. [Ref NUREG / CR 2792]
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A.5 REACTOR INTERNALS AND FUEL BLOCKAGE EVALUATION Flow blockage, such as that associated with core grid supports, mixing vanes , and debris filters are considered . Flow paths between upper downcomer and upper plenum/upper head are evaluated for long term cooling degradation resulting from flow interruption from plugging. All internal flow paths that influence long-term cooling are addressed for the potential for plugging these paths. The flow blockage associated with core grid supports, mixing vanes, and debris filter, and its effect on fuel rod temperature are considered.
The flow paths through the ABWR are illustrated in Figure A-1. ECCS flow with debris is injected inside the shroud (HPCF) and travels to the fuel inlet through the holes in the Lower Tie Plate, getting collected in the Lower Tie Plate grid/filter. Once the in-shroud level reaches the normal water level in the steam separators and spills into the RPV annulus, the debris will be mixed in the lower plenum and enter through the inlet orifice. Should the debris block most of the bundle inlet flow (over 95%) the coolant inside the bundle would form a level and flow would reverse at the channel top and enter the bundle from the upper plenum flow path for RHR and RCIC). The debris would then collect inside the bundle on the upper tie plate and spacers, to a much lower degree, but adequate long term cooling would still be achieved .
This bypass debris was assessed for !the potential blockage of coolant flow at the entrance I to the fuel assemblies as described in NEDC-33302P, Fiber Insulation Effects with Defender Lower Tie Plate (Reference 39). Tests have been performed to simulate clogging of the Defender Lower Tie Plate (DL TP) with a small concentration of fiber insulation material .
This evaluation concludes that significant BWR fuel bundle inlet clogging does not result in GNF2 fuel heat-up after the LOCA re-fill from ECCS injection . These conclusions apply to other BWR fuel bundles (e.g. , ABWR GE P8x8R) with equivalent degree of inlet resi stance as used in this evaluation .
NED0-32686-A, Utility Resolution Guide for ECCS Suction Strainer Blockage, Volume 4, Technical Support Documentation [Evaluation of the Effects of Debris on ECCS Performance GE-NE-T23-00700-15-21 March 1996 (Rev. 1)], provides a generic safety evaluation for GE11 and GE 13 fuel that bounds the ECCS components for ABWR.
Even if the fibrous insulation would plug the debris filter on the fuel, the consequences of plugging , considered from an ECCS cooling standpoint, would not impede adequate core cooling during a LOCA. With normal core spray distribution , complete flow blockage of the GEH Public IPage 46 of 105
NED0-33878 Revision 3 Non-Proprietary Information - Class I (Public) fuel lower tie plate debris filter would allow adequate core cooling to be maintained.
Consequently, it is very unlikely that excessive flow blockage of the lower tie plate debris filter would jeopardize adequate post-LOCA core cooling. It is considered inconceivable for debris to plug all channels so that flooding could not occur from below. However, if the inlet to one or more fuel channels is totally blocked from below by debris, these bundles would receive radiation cooling to the channel walls as the bypass refills, then direct cooling from water spill-over from above once the water level is restored above the top of the fuel channels. Due to the expected core reflooding rate, it is a best-estimate basis, the fuel in any blocked channels would remain well below the peak cladding temperature (PCT) limit of 2200°F.
The maximum particle sizes of the expected rust, iron oxide, epoxy paint, and sand are smaller than the fuel debris filter hole sizes and are likely to pass through without plugging.
Therefore, there is no safety concern for fuel bundle flow blockage and consequent fuel damage due to all the non-fibrous debris.
See Figure A-3 for a depiction of normal fuel channel cooling flow paths.
GEH Public IPage 47 01105
NED0-33878 Revision 3 l
Non-Proprietary Information - Class I (Public)
FLOW 1 4 - - -- - I FUELAS::. r.,lllY
c;;ORt SUPPORT ~Et,llll V ORIFICE CO~ TROI. RQO GUIDE TUO fOU R-LOBEO (ONE L061: SHOWN)
NOOMAL BUNOLE FIGURE A-3, NORMAL FUEL CHANNEL COOLING FLOW PATHS GEH Public IPage 48 of 105
NED0-33878 Revision 3 Non-Proprietary Information - Class I (Public)
Table A-4: ECCS Suction Strainer Downstream Effects-RHR Core Cooling Mode A1 Component Component Mode of Operat ion System/ Component Flowrate Fluid Vek>clty thN Component System OeKrtptions and Miuk>n Debris ln,estlon Model Wear Rate and Component Au,cll &. ry Equipment Evaluation ID Time Evaluation ECCS PIO ID ECC5 (( (( It is assumed that settling will occur (( The quantity of debris and makeup There are two types of wear of close Evilluation of Oownstreilm Effects on components in whe n the flow velocity in the process downst rea m of the st rainer needs to be running clearances within t he pump; 1) Major Components flow pilth to piping Is less than the settling velocity determined to assess wear rate of pfpinc free-Howin& ab rasive wea r and 2) The effects of debris passing through be assessed for the debris type. )) and components. packin&* type abrilsfVe wear. Wear the stra iners on downstream If settling is not present, debris will The ABWR ECCS mission time for RHR Debris considered indudes fibrous within dos1Holerance, h igh-speed components such as pumps. valves. and
)) remain in soluUon ilnd not dog lines post-LOCA performance is 30 days insulation debris and particulate debris components is a complex analysis. The heat exchan1ers has been evaluated as Determine flowrate at points in and components. (720 hours0.00833 days <br />0.2 hours <br />0.00119 weeks <br />2.7396e-4 months <br />), consistent with NRC consisting of paint chips, concrete dust. actual abrasive wear phenomena will requir~ under Re1 GuKte 1.82 Rev 4.
)) system and use the flow / velocity to 1uidi1nce. Guidance in NUREG/CR* and reflective metallic insulation shards likely not be either a cl.usic free- This evaluation indudes assessin& wear In the Safety Evaluiltion for WCAP-evaluate ~ttlin& and wear. 6988,
- final Report- Evilluiltion of small enough to pass throu1h the holes ffowin& or packin1 wear case, but a on surfaces exposed to the fluid stream 16406P (ML073520295), the NRC Chemkat Effects Phenomena in Post* of the ECCS suction stf'iliner perforilted com binat ion of the two. Both should due to various types of debris: e .1.
concluded that no settling of debris be considered in the evaluation of their LOCA Coolant," indic.ates that, plates (1/8-inch diameter). paint chips or RMI shards. Evaluating will occur in an instrument linl!
although the regulations in 10 CFR components. the potential for blockage of small installed above the horizontal plane In general, the assumptions account for 50.46{bl(5) require that long-term Consider how wear of internal surfaces clearances due to downstream debris of the process piping. Reference 42 particles larger than the screen opening cooling be maintained indefinitely of pump components will affect pump are also Included. The materials and provides guidelines for toe.ting size and assume all transportable
("for an extended period of time" ), hydraulic perfo rmance {total dynamic cleilrances for the valves. pumps. and process instrument connections {taps) milterial with the above dimensions or 30-days is typically considered to be head ilnd flow), the mechanic.I heat exchangers downstream of the on main process pipelines to ensure smaller passes through the suction an appropriate time period to performance (vibration), and pressure ABWR ECCS suction strainers are that fittings on the bottom of piping strainer unimpeded thus maximizing the demonstrate ECCS functionality and boundary inte1rity (shaft seals). essentially the same as the milterials when! they can collect crud are calculated particulate and fibrous debris that, beyond t his t ime, the decay heat and dearances for the valves. pumps.
avoided (Section 5.3.3.1.8.3). concentrations in the posHOCA process Valve and heat exchanger wetted loadin1 is small, makin& alternative and heilt exchangers downstream of Therefore, ECCS instrument lines in fluid . materials should be evaluated for coolin& possible should ECCS the PWR containment sump suction service during post-LOCA operation The maximum length of deformable susceptibility to wear, surface functionality be lost. strainers. Therefore. utilizing aspects are instillled above the horizontal particuliltes that mily pass through the abrasion, and ptu11in1. Wear may plane of the process piping. No alter the system flow distribution by applied to PWR methodology for the penetrations {holes) in pusive suction settlin& of debris in iln instrument line increasin1 How down a path ABWR is appropriate. (ref STP OCD strainers is equal to two times (2X) the in this orientiltion is expected. (decreasin1 resistance caused by 6(.3.21 maximum linear dimension of the The settlin1 velocity for 2.5 mil SS RMI penetrilllHon (hole) in the suction wear), thus starvin1 another critic.al is assumed to be 0.4 ft/sec (ref NEOO strainer. path . Or conversely, inaeased 32686 (URG)J . resistance from plu11in1 of a valve The maximum wKlth of deformable openin&, orifice, or heat exchanger A settlin& velocity of0.2 ft/swu partkulates thilt may pass throu1h the tube may c.ause wear to occur in usicned for pa int chips. Finally, a penetrations {holes) in passive suction another path that experience s settlin1 velocity of0.4 ft/s was strainer is equal to the maximum linear increased flow .
assicned to concrete dust and other dimension of th e penetration (hole) in dryweU particulates. (ref NUREG CR the suction strainer, plus 10 percent Sludge / corrosion prod. 200 lbm 6224]. (10%). !density 324 lb/ft1 per NEI 04-07 Table4-2]
A settlin1 velocity for NUCON fibers The maximum thickness of deformable used for preliminary assessment is particulates that may pass through the Inorganic Zinc (IOZ) 47 lbm 0.25 ft/sec based on having 1eometry penetrations {holes) in a passive suction (0.2516 ft 1 per URGJ of particles that would bypus the strainer is equal to one*ha1f (1/2) the Epoxy Coated IOZ 85 1bm suction strainer. {ref boundin1 NU REG maximum linear dimension of the (0.65 ftl per URG]
CR 6224 Table 8,-3 and NEI 04-07 penetration {hole) in the suction Rust Flakes SO lbm Table 4-2). strainer. (324 lb/ ft3 per NEI 04-07 Table 4-2 )
The maximum cross-sectional area of Oust/ Dirt SO lbm deformable particulates that may pass (156 lb/ ft3 per NEI 04* 07 Table 4-2]
through the penetrations (holes) in a Supp. Pool (SP) Initial Vol. (min.)::
passive suction strainer is equal to the 3455 m3 (Ref OCO T6.2-2) = 3.455 x maximum cross-sectional How area of 106 liters.
the penetration (hole) in the suction strainer, plus 10 percent (l°"l- ((
The maximum dimension {length, width and/ or thickness) of non-deformable particulates that mily pass thro u1h a suction strainer is limited to the cross-GEH Public Page 49 of 105 1
NED0-33878 Revision 3 Non-Proprietary Information - Class I (Public)
C.omponent Component Mode of Opention System/ Component Flowrate Flukf Velocity thru CDmponent System Oeseriptions and Mission Debris ln,estion Model Wear Rate and Component Auxlllary Equipment Evaluation 10 Time Evaluation sectional flow area of the penetration (hole) in the suct ion strainl!r. ( WCAP*
016406]
The materials involved are relatively stiff and incompressible and account for long, thin strands, of insulation being able to pass through tight openings.
I- It is assumed no settling of material once in sol ution. The material will tend to settle out in low flow areas in piping, the reactor vessel, the containment floor, or hold-up volum es.
It is assumed the debris forms a ))
homogeneou s solution at the start of the hpe rimental data on the effects of event. particulates on pump hydraulic performance applied to ECCS type pumps show that pump performance degradation is negligible for particulate concentrations less than 1% by volume. [Ref: NU REG/CR 2792J NU REG/CR 2792 notes conservative estimates of the nature and quantities of debris show that fine abrasives may be present in concentrations of about 0 .1% by volume (about400 ppm by weight). and that very conservative estimates of fibrous material yield concentrations of less than 1% by volume. Published data on the effects of partiC\llates on pumps generally deal with particulate concentration s at many times these values .
U71 Containment ((
Orywell Con necting Vents GEH Public Page 50 of 105 1
NED0-33878 Revision 3 Non-Proprietary Information - Class I (Public)
Component Component Mode of Operation System/ Component fiowrate Fluid Vekldty thn, Component System Descriptions and Mlssk>n Debris ln,fftlon Model Wear Rate and Compone:nt Auxllla ry Equlpm~t Evaluation ID Time Evaluatlon
))
Ell*Ol RHR System
(( (( )) The Emergency Core Cooling (ECC) (( Materials of construction fOf' ECCS Evaluation of Downstream Effects on Systems are designed to withstand a system components are listed in DCO Major Components hostile environment and still perform Table 6.1* 1 Engineered Safety The effects of debris passin& through
)) their function for 30 days followin1 an Features Component Materials. the strainers on downstream uddent. Considerinc an ECCS misstOn time of components such as pumps. valves. and
(( 30 days (720 hrs.}, the wear of heat uchan1ers has been evaluated as components subjected to the debris riequired under Re& Gutde 1.82 Rev 4, particles in solution {0.083 " SP This evaluatk>n indudes assessin& wur volume) Is considered insignificant. on surfaces exposed to the fluid stream (ref: An Assessment of Residual Heat due to various types of debris: e.g.
Removal .ind Containment Spray paint chips or RMI shards. Eva1uatin&
Pump Perform.ance Under Air and the potential for blockage of small Debris lneestin& Conditions, NUREG/ clearances due to downstream debris CR-2792) are also Included. The materials and
)) clearances for the valves. pumps. and heat e)(changers downstream of the ABWR ECCS suctk>n strainers a re essentii1lly the same as the materia ls and clearances for the valves. pumps.
and heat exchangers downstream of the PWR containment sump suctk>n strainers. Therefore. Utilizing aspects ap plied to PWR methodology for the ABWR is appropriate. [ref STP DCD 6C.3.2]
The RHR system has no ti&ht clearance valves throttled durine post LOCA operation that would be susceptible to blockace or binding, AU RHR valves 1n the post LOCA lineup will be dosed {i.e.
isolate CST suction flow path) or fully
)) open. As renected on Table 1, Valve Position Chart, on Figure 5.4-11, Resktual Heat Removal System PFC (Shel!t 2 of 2), no RHR valvl!s arl!
throttled durine post LOCA modes of operation. RHR minimum flow is ma intained by a pipin& orificl! rathl!r than throttlinc of the minimum flow valve .
RHR system check valves installed in thl! main RHR pump discharee line, minimum flow line and jockey pump dischar&I! linl! have active sa fety functions to open. These RHR valves are not susceptible to doeeine, settling or wear. The dearances of these check valves prevl!nt debris from a dversely impacting the function of thesl!
components. The check va lve materia l is carbon steel. Erosion or wear during the post LOCA credited 30-day mission GEH Public Page 51of 105 1
NED0-33878 Revision 3 Non-Proprietary Information - Class I (Public)
Component Component Mode or Operation System / Componfflt Flowrate Fluid Velocity thru Component System Descriptions
- nd Mission Debris ln,nOon Model WHr Rate
- nd Component Au >tllia ryEqulpment Evalua tion 10 Time Evaluation time writ not im pact system performance.
RHR ~tern orifice plates .ind SP and dryweU sp;ugers installed in the RHR process piplng have safety functions to maintain flow. These RHR components are not susceptible to doulng, settling or wcear. The clearances of these components prevent debris from adversely impacting the function of the se components. The orifice and sparser material is sti in less steel.
Erosion or wear durin& thll! post LOCA credited 30-day m ission time will not impact system performance.
0001 B Suction (( (( )) (( ((
Strainer
)) ))
The sizin& of the RH R suction strainers conforms to the guidance of Reg Guide 1.82. The sizing is based on s;1tisfyin& the NPSH requirements at runout flow, plus margin, with postulated p iping insulation debris in the SP accumulated on the pump suction strainers. The sizing of the strillners is based on 30 days of post-LOCA operation.
RHR desicn has ii provision for installiltion of a temporary strainer in Heh loop durinc pre-operational and stilrtup testinc .
Strainers are located to ilvoid air entrainment during a LOCA blowdown or from vortexing action and away from the safety relief valve quencher discharee zones.
Stu iners shiltl be sized to prevent do11in1 of pump internal passages.
(Ref: 31113-0E11*2010 (Ref. 321] .
))
X-202 Penetration (( (( )) (( The ECCS piping/ component flow area exceeds the ma1dmum dimension of the debris particles. Therefore, clo11in1 is not
)) considened credible.
GEH Public Page 52 of 1051
NED0-33878 Revision 3 Non-Proprietary Information - Class I (Public)
Component Component M ode of Operat ion System / Componfflt f lowrate Flu id Velocity thru c.omponent System Descriptions and M tsslon Debris Ingestion Model Wear Rate and Component Au xlllary Equipment Evaluation 10 Time Evaluation
))
FOOlB Motor (( (( The ECCS piping / component flow area
(( ))
Operated exceeds the maximum dimension of the Block Valve debris particles. Therefore, clogging is not
)) considered credible.
))
(0018 RHR Pum p B (( (( (( The ECCS piping / component flow area As described in NU REG / CR 2792, An NED0-32686 (URG) Vol 4 Evaluation of
(( ))
exceeds the maximum dimension of the Assessment of Residual Heat Remova l the Effects of Debris on ECCS debris particles . Therefore, clogging is not and Containment Spray Performance Performance (GE*NE-T23-00700-1S. 21),
)) considered credible. Under Air and Debris Ingesting addresses safety and operational Conditions, concludes that under concerns for failure of ECCS pumps LOCA conditions with generated associated with particles that pass debr is at the pump, pump through the ECCS suction strainers.
performance degradation is expected The ECCS pump design is coordinated to be negligible . In the event of shaft with the ECCS suction strainer sizing to seal failure due to wear or loss of prevent clogging of pump internal cooling fluid, seal safety bushings lim it passages including mechanical seal leakage rates. This is based on a assemblies. The consequence of a debris concentration less than 0.5% by plugged pump seal line would be high
)) volume. seal temperature and poor seal life.
When considering long-term pump The ECCS pump includes a mechanical operation and performance, it is seal assembly with cyclone particle necessary to consider how wear of separator and seal*cooling heat internal pump components will affect exchanger. A cyclone separator type of the pump hydraulic performance filtration is provided to maintain a clean (total dynamic head and flow), the
)) mechanical performance (vibration),
cooling water supply to the seal.
and pressure boundary integrity (shaft seals). The wear of the dose running The size of orifices used to control the clearances may affect the hydraulic flow to ECCS pump seals is specified by performance because of increased the pump manufacturer to ensure the internal or bypass leakage . Multistage pump seal cooling lines are not pumps, designed for high head susceptible to plugging by debris not service, usually operate at speeds filtered by the cyclone separator type above the first natural frequency of fi lter or debris larger than the seal the rotating assembly. The running cooling line orifice hole diameter.
clearances of the suction side and discharge side of each impeller stage Wea r rings and bushings are specifically are designed and manufactured to designed (hard materials) to resist wear provide hydrostatic support and due to hard particulates in the process damping for the rotating assembly, fluid. tf the concentration of hard thus allowing operation at super-particulates is unusually excessive, the critical speeds without dynamic effect could be a long*term instability. Increasing the close deterioration in the pump running clearances due to wear may performance, in the form of low pump reduce the overall shaft support head. The requirement of 30 days of stiffness at each impeller location, GEH Public Page 53 of 105 1
NED0-33878 Revision 3 Non-Proprietary Information - Class I (Public)
Component Component Mode of Operation System/ Componfflt Fk>wrate Fluid Ve locity t hru Component System Descriptions and Mlssk>n Debris ln,Htion Model Wear Rete a nd Component Au,cl lla ry Equipment Evaluation ID Tim e Evaluatlon thus affectin& the dynamic stabil ity of post LOCA operation is not considerl!d the pump. Debris in the pumped fluid lonr:-term.
may affect the sealing capability of mechanical shaft seals. These seals are Seal Faces dependent on seal injection flow to cool the primary seal com ponents. New seal faces are tapped to very flat Debris in the pumped flow has the and smooth surfaces. The workin& gap potential of blodc.in& the seal injection between the faces is a fracttOn of a now path or oflimitine the micron. This means that larie performance of the seal componenu particulates would pass over the seal due to debris buildup in bellows and faces, and would not enter the sprin1s. These effecu may lead to interface to destroy the smoothness of primary sul failure. Graphite safety the face and cause leakage.
bushin1s {disaster bushings) milly fail if e>Cposed to high pressure fluid with For the passive strainer with the holes debris followin& a prima ry seal failure sized at 0.12S in., little fiber is expected thus, providin& an o utside to pass throuch after the Initial filter containment path for post-LOCA fluid .
bed is formed . Little of the other debris
([ (except for minim um sized iron oxide sludce) is expected to pass after the initial filter bed precoat is formed .
Therefore, all materials would most likely pass throuch the orifice if 1% by volume of fiber does not cause a hiehly unlikely
- blitz" which plugs the orifice.
Because all particles are larger than a fractio n of a micron, they would not enter the pump seal face . For shafts
)) and bushincs, debris in quantities of It is expected that ECCS pumps one percent or less of the pump flu id is opented for 30 days (720 hrs.) under likely to not constitute a major threat modes of operation assessed and to the bushinc integrity.
pumpin& liquid at maximum suspended solids will not wear to a point where vibntion will affect ([
opera bility.
GEH Public Page 54 of 105 1
NED0-33878 Revision 3 Non-Proprietary Information - Class I (Public)
Component Component Mode of Operation System/ Component Flowrate Flukl Velocity thru Component System Descriptions and M ission Debris ln,estion Model Wear Rate and Component Auxll lary Equipment Evaluat ion 10 Time Evaluation
))
ECCS pump performance for the specific plant as-built con figuration w ill r ll!:quire dem onstriltion of accep table performance under design condit ions including design de bris loading.
Demonstration of acceptable performance fo r as-built ECCS pumps is validated under QME-1 2007, Qualification of Active Mechanical Equ ipment Used in Nuclear Power Plants as endorsed by RG 1.100, "Seismic Qualification of Electrical and Active Mechanical Equ ipment and Functional Qualification of Active Mtchanical Equipm e nt fo r Nuclear Power Ptants/ Revis'ion 3, September 2009 .
F0028 Check Valve ([ (( )) ([ The ECCS piping / component flow are a exceeds the maximum dimension of the debris particles. Therefore, cloning is not
)) consid@red credible.
GEH Public Page 55 of 105 1
NED0-33878 Revision 3 Non-Proprietary Information - Class I (Public)
Component Component Mode of Operation System/ Com ponent f lowrate Flu id Velocity thru Component System Descriptions 1nd Mission Debris Ingestion Model W ear Rat e and Component Auxllla ry Equlpment Evaluat ion 10 Time Evaluation
))
F003B Manual Block The ECCS piping/ component flow area
(( (( )) ((
Valve exceeds the maxi mum dimension of the debris particles. Therefore, clogging is not
)) considered credible.
))
80018 Heat (( (( The RHR heat exchanger tube ID is 17 .22 NED0-32686 (URG) Vol 4 includes
(( ))
Exchanger mm. The ECCS strainer will restrict debri s evaluation of ECCS heat exchangers.
to less than 3.18 mm . Therefore, the RHR This assessment was adjusted for the
)) heat exchanger will not become clogged ABWR RHR heat exchanger with from debris passing downstream of the suppression pool water flowing though ECCS suction strainer. the tubes of the ~eat exchanger. As described in ABWR DCD section 5.4.7.1, the ABWR RHR heat exchanger has taken advantage of a design change that was made with respect to prior BWRs. ABWR has the reactor water flowing through the tube side of the heat exchanger, whereas, prior BWRs had the reactor water flowing through the shell side. The primary purpose for
)) the change was to reduce radiation buildup in the heat exchanger by providing a more open geometry flo w path through the center of the tubes, as opposed to the shell side construction of spacers, baffles, and low flow velocity locations, which can provide places for radioactive sludge to accumulate.
Heat Exchangers Significant effect on RHR heat exchanger performance can occur if a large quantity of debris is retained inside the heat exchangers causing blockage of the flow and/or fo uling of the tubes. Flow from the suppression pool is channeled through the tubes of the RHR heat exchangers. The tube side flow velocity of a RHR heat exchanger is approximately 2 ft/ sec. At this velocity, the flow will entrain the small particles without allowing them to settle in the GEH Public Page 56 of 105 1
NED0-33878 Revision 3 Non-Proprietary Information - Class I (Public)
Component Component M ode of Operation System/ Component Flowrate Hukt Velocity thru Component System Descriptions *nd Mfssk>n Debris ln,estion Model Wear Rate and Component Au,clllary Equipment Evaluation ID Time Evaluation heat exchanger. Thi! tube size is 0.68" diameter. The results of the size distribution analyses are evaluated as follows:
- 1. The rust chips are the largest, but are very likely to break into smaller pieces.
Considering the possibility that the largest chips get through the strainer holes and through the pumps without being broken up, (not considered credible), they w ill pass th rough the heat exchanger tubes. Iron oxide (Fe20 1 or Fe]O. ) will not promote oxidation and corrosion on the inside diameter of the stainless steel tubes . Therefore, rust debris particles will not contribute to fou ling and/ or thinning of the tubes.
- 2. EPOlCY paint chips are small and light enough that they will be swept through the heat exchanger-5, and are of no concern.
- 3. The size of the sand grains are small enough that it is unlikely that they will be captured along the flow path, but may be heavy enough to settle in pockets of low velocity near the tube sheets of the heat uchanger.
Because they will not settle on the inner surface of the tubes, they will not affect the heat exchanger performance.
- 4. Of the samples evaluated in Reference 1, only 0.1% of the fiber population had a length of0.39" or greater. With this length, it is unlikely they could attach to the inner diameter of the RHR heat exchanger tubes.
Moreover, the fibers were so fragile that any attempt to disperse the clumps caused extensive brtakage of the longer fibers . These fiber-5 also will be easily swept away and carried out of the heat exchanger without affecting heat exchanger performance. In summary, a review of heat exchanger performance concludes that nonsotuble insulation material will not deteriorate the performance of the as-built heat exchanger. The rust chips could present some potential effect to RHR heat exchanger performance. However, this concern is minimized by the fact that a large fraction of the bigger chips are so thin th at they will flow through the heat exchangers while others will be broken into still smaller pieces by the rapid flow and therefore easily pass GEH Public Page 57 of 105 1
NED0-33878 Revision 3 Non-Proprietary Information - Class I (Public)
Component Component Mode of Opffatlon System/ Componfflt flowrate flukl ve,odty thru C.omponent System DncripUons *nd Mlssk>n Debris tncestlon Model Wear Rate and Component Au xlllaryEquipment Evaluation 10 Time Evaluation throuah the heat l!xch.inger. Thi!: key f actors in heat exchanger performance ue the routine maintenance, insp@ction, and deaning of the: heat excho1n1@r, Debris that pass through the ECCS suction strain cm do not affect heat exchan1er perform.1nce The:refore, there is no abnormal operational or ufety concern with the identified debns on RHR hut uchancer performance, assuming they are properly maintained.
f0048 Motor (( )) (( The ECCS pipin& / component flow area
((
Operated exceeds the maximum dimension of the Control Valve debris particles. Therefore, clogging is not
)) considered credible.
))
FE-0068 Flow Element (( The ECCS piping / component flow areil
(( )) ((
exceeds the maximum dimension of the debris partkles. Therefore, clo11in1 is not
)) considered cr~ible.
))
00038 flow (( (( )) (( ((
Restrictin1 Orifice ))
))
GEH Public Page 58 of 105 1
NED0-33878 Revision 3 Non-Proprietary Information - Class I (Public)
Component Component Mode of Operation System/ Compon~t Flowrate Flu kt Velodty thru Component System Descriptions and Mlssk>n Debris ln,estlon Model Wear Rllte and Component AuxlllaryEquipm~t Evaluation 10 Time Evaluation
))
The ECCS piping / component flow area FOOSB Motor (( (( )) ((
Operated exceeds the maximum dimension of the Block Valve debris particles. Therefore, clogging is not
)) considered credible.
))
Penetration (( The ECCS piping / component flow area
((_ (( ))
exceeds the maximum dimension of the debris particles . Therefore, clogging is not
)) considered credible.
))
f006 )) (( The ECCS piping / component flow area Check Valve
(( ((
exceeds the maximum dimension of the (N2 Testable) debris particles. Therefore, clogging ts not
)) considered credible.
))
f007 Manual Block The ECCS piping / component flow area
(( (( )) ((
Valve exceeds the maximum dimension of the debris particles. Therefore, clogging is not
)) considered credible.
))
Reactor RHRSpargers (( The ECCS piping/ component flow area As described in NED0-32686 (URG) Vol
(( )) ((
Internals exceeds the maximum dimension of the 4, containment spray nozzles were
[Reactor debris particles. Therefore, clogging is not found to have orifices or openings sized Pressure )) considered credible. from 0.125" to 1.5". It is highly unlikely Vessel 811] that any of the identified debris which would be expected to be much smaller GE_ H_
Public Page 59 of 105 1
NED0-33878 Revision 3 Non-Proprietary Information - Class I (Public)
Component Component Mode of Operation System/ Component Fiowrate Fluid Velocity thru Component System Descriptions and Mlssk>n Debris ln1esUon Model Wear Rate and Component Auxll laryEqulpment Evaluation 10 Time Evaluation by the time it reached the orifices, would be able to block the orifice. A very few longer particles would be expected to pass through the passivl!:
)) suction strainers.
There is no safety significance due to the small number of particles versus the large number of containment spray nozzles and orifices. Therefore, the expected debris will be of no sa fety concern for the containment spray operation.
Reactor Reactor (( (( )) RHR injection is through the spargers The reactor vessel flow area orifices Internals Assembly above the core outside the core exceed the maximum dimension of the
[Reactor shroud in the annulus. Flow is directed debris particles . Therefore, clogging is not Pressure )) through the inlet orifice / lower tie considered credible .
Vessel 811} plate to the fuel assembly from lower plenum flooding.
Flow from spray is also available through the bypass hole / lower tie plate.
- Flow is also available to the fuel as"semblies through the upper tie plates.
Jll Fuel (( (( )) The ABWR evaluation examines the As described in NED0* 32686 {U RG) Vol Assembly effects of bundle inlet clogging that 4, a safety evaluation by the GEF has reduces the available inlet flow from addressed the fiberglass debris as it
)) natural circulation phenomena might affect the new GEll and GE13.
following initial core refill when the This document states that even though core region is covered by a two-phase the fibrous insulation would not be mixture . ([ expected to plug the debris filter, the consequences of plugging were considered from an ECCS cooling standpoint. As a result of these considerations, it was concluded that
)) adequate core cooling would be Once the bundle decay heat ha s provided during a LOCA. With normal decrea sed and insufficient voids exist core spray distribution, complete flow to maintain the level in the bundle blockage of the fuel lower tie plate above the top of the fuel channel, debris filter would allow adequate core adequate cooling from the upper cooling to be maintained.
plenum spillover will exist. Thus, the Consequently, it is very unlikely that evaluation concludes that for excessive flow blockage of the lower tie significant bundle inlet clogging plate debris filter would jeopardize following initial core refill, BWR fuel adequate post*LOCA core cooling. It is bundle cooling is assured . considered inconceivable for debris to plug all channels so that flooding could not occur from below. However, if the inlet to one or more fuel channels is totally blocked from below by debris, these bundles would receive radiation cooling to the channel walls as the bypa ss refills, then direct cooling from water spill*over from above once the water level is restored above the top of GEH Public Page 60 of 105 1
NED0-33878 Revision 3 Non-Proprietary Information - Class I (Public)
Component CompoMnt Mode of Oper9Uon System/ Component Flowrate Flukl Velocity thru Component System Oescrtpt6ons *nd Mission Debris tncestion Model Wur Rate and C.Omponent Auidllairy Equipment Evaluation ID Time Evaluation the fuel channels. The fuel in any b locked channels would remain well below the peak dadding temperature (PCT) limit of 22cxrF.
Thi! maximum particle sizes of the expected rust, iron oxide, epoxy paint, and Hnd are smilller thiln the fuel debris tilter ho~ sizes and ue liker, to pass throuch without plugainc.
Therefore, there is no s.ifety concern for fuel bundle now blocka&e and cons~uent fuel damage due to all the debris Identified.
GEH Public Page 61 of 105 1
NED0-33878 Revision 3 Non-Proprietary Information - Class I (Public)
Table A-5 : ECCS Suction Strainer Downstream Effects-RHR Suppression Pool Cooling Mode 81 Component Component M ode of Operation System/ Component Flowrate fluid Velocity t hn, Component System Descriptions a nd Mission Debris ln1t'fllon Model Wear Rate and Component AuxllfaryEquipment Evaluation 10 Time Evaluation ECCS PIDID ECCS components (( (( It is assumed that settling will occur (( [The quantity of debris and makeup There are two types of wear of dose Evaluation of Downstream Effects on in flow path to be when the flow velocity in the process downstream of the strainer needs to be running dearances within the Major Components assessed piping is less than the settling determined to assess wear rate of piping pump; 1) free-flowing abrasive wear The effects of debris passing through the velocity for the debris type. and components) and 2) packing-type abrasive wear. strainers on do wnstream components Wear within close-tolerance, h igh-
)) If settling is not present, debris will )) speed components is a complex.
such as pumps. valves. and heat remain in solution and not clog lines Debris considered includes fibrous exchanger-5 has been evaluated as Determine flow rate at points in The ABWR ECCS mission time for RHR analysis. The actual abrasive wear and components. required under Reg Guide 1.82 Rev 4.
)) system and use the flow / velocity to post-LOCA performance is 30 days insulation debris and particulate debris phenomena will likely not be either a The settling velocity for 2.5 mil SS consisting of paint chips, concrete dust, This evaluation includes assessing wear evaluate settling and wear (720 hours0.00833 days <br />0.2 hours <br />0.00119 weeks <br />2.7396e-4 months <br />), consistent with NRC classic free-flowing or packing wear RMI is assumed to be 0.4 ft/sec (r ef and reflective metallic insulation shards on surfaces ex.posed to the fluid stream guidance. Guidance in NUREG/CR- case, but a combination of the two.
NEOO 32686 (URG)] small enough to pass through the holes due to various types of debris: e.g . paint 6988, "Fina l Report- Evaluation of Both should be considered in the of the ECCS suctio n st ra ine r chips or RMI shards. Evaluating the In the Safety Evaluation for WCAP* Chemical Effects Phenomena in Post- evaluation of their components.
perforated plates (1/8-inch potential for blockage of small clearances 16406P (ML073520295}, the NRC LOCA Coolant," indicates that, diameter) due to downstream debris are also concluded that no settling of debris although the regulations in 10 CFR Consider how wea r of internal included . The materials and clearances will occur in an instrument 1ine 50.46(b)(5) require that long-term s urfa ces of pump components will for the valves. pumps. and heat installed above the horizontal plane cooling be maintained indefinitely In general, the assumptions account for exchangers downstream of the ABWR of the process piping . Reference 42 ("for an extended period of time" ), affect pump hydraulic performance particles larger than the screen opening ECCS suction strainers are essentially the provides guidelines for locating 30-days is typically considered to be (total dynamic head and flow), the size and assume all transportable same as the materials and clearances for process instrument connections an app ropriate time period to mechanical performance (vibration),
material with the above dimensions or the valves. pumps. and heat exchangers (taps) on main process pipelines to demonstrate ECCS functionality and and pressure boundary integrity smaller passes through the suction downstream of the*PWR containment ensure that fittings on the bottom of that, beyond th is time, the decay (shaft seals).
strainer unimpeded thus maximizing the sum p suction stra iners. Therefore.
piping where t hey can collect crud heat loading is small, making calculated particulate and fibrous debris Utilizing aspects applied to PWR are avoided (Section 5.3.3.1.8.3) . alternat ive cooling possible should concentrations in the post-LOCA process Valve and heat exchanger wetted methodology for the ABWR is Therefore, ECCS instrument lines in ECCS functionality be lost.
fluid . materials should be evaluated for appropriate. [ref STP DCD 6C.3.2]
service during post-LOCA operation susceptibility to wear, surface are installed above the horizontal abrasion, and plugging. Wear may plane of the process piping. No The maximum length of deformable alter the system flow distribution by settling of debris in an instrument particulates that may pass through the increasing flow down a path line in this orientation is expected . penetrations (holes) in passive suction (decreasing resistance caused by strainers is equal to two times (2X) the A settling velocity of0.2 ft/ s was wear), thus starving another critical assigned for paint chips. Finally, a maximum linear dimension of the path . Or conversely, increased penetration (hole) in the suction strainer.
settling velocity of 0.4 ft/s was resistance from plugging of a valve assigned to concrete dust and other opening, orifice, or heat exchanger drywell particulates. [ref NUREG CR The maximum width of deformable tube may cause wea r to occur in 6224 1 - f--- particulates that may pass through the another path that e11.periences A settling velocity for NUCON fiber-5 penetrations (holes) in passive suction increased flow .
used for preliminary assessment is straine rs is equal to the maximum linear Sludge/ corrosion prod . 200 lbm 0 .25 ft/sec based on having d imension of th e penetration (hole) in [density 324 lb/ftl per NEI 04-07 geometry of particles that would the suction strainer, plus 10 percent Table4-2]
bypass the suction strainer. [ref (10%).
Inorganic Zinc (IOZ) 47 lbm bounding NUREG CR 6224 Table B-3 [0.25 16 ftl per URG]
and NEI 04-07 Table 4-2]
The maximum thickness of deformable Epoxy Coated IOZ 85 lbm particulates that may pass through the [D.65 ft 1 per URG]
penetrations (holes) in a passive suction Rust Flakes SO lbm strainer is equal to one-half (1/2) the 1324 lb/ftl per NEI 04-07 Table 4-2]
maximum linear dimension of the penetration (hole) in the suction strainer.
Oust / Dirt 150 1bm (156 lb/ ft1 per NEI 04-07 Table 4-21 The maximum cross-sectional area of Supp . Pool (SP} Initial Vol. (min.) =
deformable particulates that may pass 3455 m3 (Ref DCO T6 .2-2) = 3.455 11.
through the penetrations (holes) in a 10' liters.
passive suction stra iner is equal to the maximum cross*sectional now area of the GEH Public Page 62 of 105 1
NED0-33878 Revision 3 Non-Proprietary Information - Class I (Public)
Component Component Mode of Operat ion System/ Component Ftowrate Fluid Velocity t hn, Component System DescrlpUons and M ission Wear R*te and Component Auxlllary Equipment Evaluation 10 Ti me Evaluation penetration (hole) in the suction strainer, ((
plus 10 percent (10%).
The maximum dimension {length, width and/ or thickness) of non-deformable particulates that may pass through a suction strainer is limited to the cross-sectional flow area of the penetration (hole) in the suction strainer. [ WCAP-016406-PJ The materials involved are relatively stiff and incompressible and account for long, thin strands, of insulation being able to pass through tight openings.
It is assumed no settling of material once in solution . The material will tend to ))
settle out in low flow areas in piping, the E,cperimental data on the effects of reactor vessel, the containment floor, or particulates on pump hydraulic hold-up volumes.
performance applied to ECCS type It is assumed the debris forms a pumps show that pump performance homogeneous solution at the start of the degradation is negligible for event. particulate concentrations less than 1% by volume . [Ref: NU REG/CR 2792]
NU REG/CR 2792 notes conservative estimates of the nature and quantities of debris show that fine abrasives may be present in concentrations of about 0.1% by volume (about 400 ppm by weight).
and that very conservative estimates of fibrous material yield concentrations of less than 1% by volume. Published data on the effects of particulates on pumps generally deal with particulate concentrations at many times these values.
U71 Containment ((
Orywell Connecting Vents GEH Public Page 63 of 105 1
NED0-33878 Revision 3 Non-Proprietary Information - Class I (Public)
Component Component M ode of Operatk>n System / Component Flowrate Fluid Velocity thru Component System DestripUons and M iuk>n O.bris ln1estion Model We.r Rate and CompoMnt Auxll laryEqu lpment Evaluation 10 Time Evaluation
- f-----
))
Ell-01 RHR System The Emergency Core Cooling (EC() DCD 531.3.2.3 Water Quality and Materials of construction for ECCS Evaluation of Downstream Effects on
(( (( )) Systems ue designed to withstand a Submergence, provides reactor water system components are listed in OCD Major Components hostile environment and still perform quality characteristics for the design basis Table 6.1-1 Engineered Safety The effects of debris passing through the
)) their function for 30 days following LOCAs inside primary containment. Features Component Materials. strainers on downstream components an ilccident. such as pumps. valves. and heat
((
(( Considering an ECCS mission time of exchangers has been evaluated as 30 days (720 hrs.), the wear of required under Reg Guide 1.82 Rev 4.
components subjected to the debris This evaluation includes assessing wear partides in solution (0.083 % SP on surfaces exposed to the flu id stream volume) is considered insignificant. due to various types of debris: e.g. paint chips or RMI shards. Evaluating the potentia l for blockage of small clearances (ref: An Assessment of Residual Heat due to downstream debris are also Removal and Containment Spray included. The materials and clearances Pump Performance Under Air and for the valves. pumps. and heat Debris Ingesting Conditions, NU REG/ exchangers downstream of the ABWR CR-2792) ECCS suction strainers are essentially the same as the materials and clearances for the valves. pumps. ilnd heilt exchilngers downstrea m of the PWR containment sump suction strainers. Therefore.
)) Utilizing aspects applied to PWR mdhodology for the ABWR is appropriate. (ref STP DCD 6C.3.2]
The RHR system has no tight clearance valves throttled during post LOCA operation that would be susceptible to blockage or binding . All RHR valves in the post LOCA lineup will be closed (i.e.
isolate CST suction flow path} or fully open. As reflected on Table 1, Valve Position Chart, on Figure S.4-11, Residual Heat Removal System PFD (Sheet 2 of 2),
)) no RHR valves are throttled during post LOCA modes of operation. RHR minimum flow is mainta ined by a piping orifice rather than throttling of the min imum nowvatve.
RHR system check valves installed in the main RHR pump discharge line, minimum flow line and jockey pump discharge line have active safety function s to open.
These RHR valves are not susceptible to clogging, settling or wear. Th e clearilnces of these check Vil Ives prevent debris from adversely impacting the function of these GEH Public Page 64 of 105 1
NED0-33878 Revision 3 Non-Proprietary Information - Class I (Public)
Component Component Mode of Operat km System / Compone nt Flownte Fluid Velod ty t hru Component System Ot!scri pUons and Missk>n Debris ln1ntk>n Model Wear Rat e and Component Auxllla ry Equipment Evaluation 10 Tim e Evaluat lon components. The check valve m ateria l is carbon steel. Erosion or weu during the post LOCA credited 30-day mission time will not im pact system perform ance.
RHR system orir1ee plates ilnd SP and drywell spar1ers installed in the RHR process piping have safety functtOns to ma intain flow, These RHR components are not susceptible to clo&ein&, settling or wear. The clearances of these components prevent debris from adversely impacting the functtOn of these components. The orifice and sparger material is stainless steel. Erosion or wear during the post LOCA credited 30-day mission time will not impact system performance.
0001 B Suction Strainer (( (( ]) (( ((
)) ])
The sizin1 of the RHR suction strainers conforms to the 1uldance of Reg Guide 1.82 . The sizin1 is based on Ytisfying the NPSH requirements at runout flow, plus ma11in, with postulated pipinc insulat10n debris in the SP accumu~ted on the pump suction strainers. The sizinc of the strainers Is based on 30 days of post*
LOCA operation.
RH R desifn has a provision for installation of a temporary stra iner in each loop durinc pre-operationa l and startup testinc .
Strainers are louted to avoid air entrainment durinc a LOCA blowdown or from vortexln& action and away from the safety relief valve quencher discharge zones.
Strainers shall be sized to prevent douinc of pump internal passages.
(Ref: 31113-0£11-2010 {Ref. 32)1
])
GEH Public Page 65 of 105 1
NED0-33878 Revision 3 Non-Proprietary Information - Class I (Public)
Component Component Mode of Operation System/ Component Ftowrate Fluid V<<!lodty thru Component System DescrlpUons a nd Mission Debris lngntion Model Wear Rate and Component Auxiliary Equipment Evaluation ID Tim e Evaluation X*202 Penetration (( )) (( The ECCS piping / component flow area
(( e,cceeds the ma)(imum dimension of the debris particles. Therefore, clogging is not
)) considered credible.
))
F001B Motor Operated (( (( The ECCS piping / component flow area
(( ))
Block Valve exceeds the maximum dimension of the debris particles. Therefore, clogging is not
)) considered credible.
))
(00 18 (( (( The ECCS piping / component flow area As described in NU REG /CR 2792, An NED0-32686 (URG) Vol 4 Evaluation of RHR Pump 8
(( (( ))
exceeds the maximum dimension of the Assessment of Residual Heat Removal the Effects of Debris on ECCS debris particles. Therefore, clogging is not and Containment Spray Performance Performance (GE-NE-TB-00700-15-21),
)) considered credible. Under Air and Debris Ingesting addresses safety and operational Conditions, concludes that under concerns for failure of ECCS pumps LOCA conditions with generated associated with particles that pass debris at the pump, pump through the ECCS suction strainers.
performance degradation is expected The ECCS pump design is coordinated to be negligible. In the event of shaft with the ECCS suction strainer sizing to seal failure due to wear or loss of prevent clogging of pump internal cooling fluid , seal safety bushings passages induding mechanical seal limit leakage rates. This is based on a assemblies. The consequence of a debris concentration less than 0 .5% plugged pump seal line would be high
)) by volume. seal temperature and poor seal life .
When considering long-term pump The ECCS pump includes a mechanical operation and performance, it is seal assembly with cyclone particle necessary to consider how wear of separator and seal-cooling heat internal pump components will affect exchanger. A cyclone separator type of the pump hydraulic performance filtration is provided to maintain a clean
)) (total dynamic head and flow), the cooling water supply to the seal .
mechanical performance (vibration),
and pressure boundary integrity (shaft seals) . The wear of the close The size of orifices used to control the running clearances may affect the flow to ECCS pump seals is specified by hydraulic performance because of the pump manufacturer to ensure the increased internal or bypass leakage. pump seal cooling lines are not Multistage pumps, designed for high susceptible to plugging by debris not head service, usually operate at filtered by the cyclone separator type speeds above the first natural filter or debris larger than the seal cooling frequency of the rotating assembly. line orifice hole diameter.
The running clearances of the suctio n GEH Public Page 66 of 105 1
NED0-33878 Revision 3 Non-Proprietary Information - Class I (Public)
Component Component Mode of Operation System/ Component Fk>wnte Fluid Velocity thru Component System OescrlpUons and Mission 04ebris ln1~ion Model WNr Rate a nd Component Auxiliary Equipment Evaluation ID Time Evaluation side and discharge side of each impeller stage are designed and Wea r rings and bushings are specifically manufactured t o provide hydrostatic designed (hard materials) to resist wear support and damping for the rotating due to hard particulates in the process assembly, thus allowing operation at fluid. If the concentration of hard sup@r*critical speeds without dynamic particulates is unusually excessive, the instability. Increasing the closl!!: effect could be a long-term deterioration running clearances due to wear may in the pump performance, in the form of reduce the overall shaft support low pump head. The requirement of 30 stiffness at each impeller location, days of post LOCA operation is not thus affecting the dynamic stability of considered long-term .
the pump. Debris in the pumped fluid may affect the seating capability of mechanical shaft seats. These seals Seal Faces are dependent on seal injection flow New seal faces are lapped to very flat and to cool the primary seal components. smooth surfaces. The working gap Debris in the pumped flow has the between the faces is a traction of a potential of blocking the sea l m icron. This means that large injection flow path or of lim iting the particulates would pass over the seal performance of the seal components faces, and would not enter the interface due to debris buildup in bellows and to destroy the smoothness of the face springs. These effects may lead to and cause leakage.
primary seal failure. Graphite safety bushings (disaster bushings) may fail if exposed to high pressure fluid with For the passive strainer with the holes debris following a primary seal failure sized at 0.125 in., little fiber is expected thus, providing an outside to pass through after the initial filter bed containment path for post-LOCA is formed, and also tittle of the other fluid. debris (except for minimum sized iron oxide sludge) is expected t o pass after
(( the initial filter bed precoat is formed .
Therefore, alt materials would most likely pass through the orifice if 1% by volume of fiber does not cause a highly unlikely "blitz" which plugs the orifice. Because all particles are larger than a fraction of a micron, they would not enter the pump seal face. For shafts and bushings, debris in quantities of one percent or less of the pump fluid is likely to not constitute a
)) major threat to the bushing integrity.
It is expected that ECCS pumps ((
operated for 30 days (720 hrs.) under modes of operation assessed and pumping liquid at maximum suspended solids will not wear to a point where vibration will affect operability.
GEH Public Page 67 of 105 1
NED0-33878 Revision 3 Non-Proprietary Information - Class I (Public)
Component Component Mode of Operatton System/ Component Flowrate Ftuid Velocity thru Component System De$crlptlons and Mission ~bris Ingestion Model Wear Rate and Component AuxllJary Equipment Evaluation ID Time Evaluation
))
ECCS pump performan ce for the specific plant as-built configuration will require demonstration of acceptable performan ce under design conditions including design debris loading.
Demonstration of acceptable performance for as-built ECCS pumps is validated under QME-12007, Qualification of Active Mechanical Equipment Used in Nuclear Power Plants as endorsed by RG 1.100, "Seismic Qualification of Electrical and Active Mechanical Equipment and Functional Qualification of Active Mechanical Equipment for Nuclear Power Plants/
Revision 3, September 2009 GEH Public Page 68 of 105 1
NED0-33878 Revision 3 Non-Proprietary Information - Class I (Public)
Component Component Mode of Operation System/ C.Om ponent f k>wrat e Fluld Velocity thN Component System OescrlpUons and MissJon ~bris ln1estion Model Wear Rate a nd Component Auxll l~ry Equ ipment Evaluatlon 10 Time Evaluation F002B Check Valve The ECCS piping/ component flow area
(( (( )) ((
e1Cceeds the maximum dimension of the debris particles. Therefore, clogging is not
)) considered credible.
))
Manua1Slock (( (( The ECCS piping / component flow are.i F0038
(( ))
exceeds the ma,dmum dimension of the Valve debris particles. Therefore, clogging is not
)) considered credible.
))
BOOIB Heat Exchanger
(( (( )) (( The RHR heat exchanger tube ID is 17.22 NED0-3 2686 (URG) Vol 4 includes mm. The ECCS strainer will restrict deb ris evaluation of ECCS heat exchangers :
to less than 3.18 mm . Therefore, the RHR This assessment was adjusted for the
)) heat e,cchanger will not become clogged ABWR RHR heat exchanger wrth from debris passing downstream of the suppression pool water flowing though ECCS suction strainer. the tubes of the heat exchanger. As described in ABWR DCO section 5.4 .7.1, the ABWR RHR heat exchanger has taken advantage of a design change that was made with respect to prior BWRs. ABWR
)) has the reactor water flowing through the tube side of the heat eKchanger, whereas, prior BWRs had the reactor water flowing through the shell side. The primuv purpose for the change was to reduce radiation buildup in the heat exchanger by providing a more open geometry flow path through the center of the tubes, as opposed to the shell side construction of spacers, baffles, and low flow velocity locations, which can provide places for radioactive sludge to accumulate.
Heat Exchangers Significant effect on RHR heat exchanger performance can occur if a large quantity of debris Is retained inside the heat exchangers causing blockage of the flow and/or fouling of the tubes. Flow from the suppression pool is channeled through the tubes of the RHR heat exchangers. The tube side flow velocity of GEH Public Page 69 of 105 1
NED0-33878 Revision 3 Non-Proprietary Information - Class I (Public)
Component Component Mode of Operatton System/ Component Flownite flu id Velocity thru Component System Descrfptfons and Missfon ~bris ln1estk,n Model Wear Rate and Component Auxiliary Equipment Evaluatlon ID Ti m e Evaluation a RHR heat @xcha nger is approximately 2 ft/ SM. At this velocity, the flow will entrain the small particles without allowing them to settle in the heat t!:XChanger. The tube size is 0.68 inch diameter. The results of the size distribution analyses are evaluated as follows:
- 1. The rust chips are the largest, but are very likely to break into smaller pieces.
Considering the possibility that the largest chips &et through the strainer holes and through the pumps without being broken up, (not considerll!:d credible), they will pass through the heat exchanger tubes. Iron oxide (Fe1 0 i or F~O,) will not promote oxidation and corrosion on the inside diam eter of the stainless st eel tubes . Therefore rust debris particles wilt not contrib ute to fouling and/ or thinning of the tubll!:s.
- 2. Epoxy paint chips arll!: small and light 11!:nough that thll!:y wilt bll!: swll!:pt through thll!: hll!:at e>cchangers, and arll!: of no concll!:m .
- 3. The sizll!: of the sand grains arll!: small 11!:nough that it is unlikely that thll!:V will be capturll!:d along the flow path, but may bll!:
hll!:avy 11!:nough to settle in pod:11!:tS of low velocity near the tubll!: shell!:ts of the heat e>cchanger.
Becausll!: thll!:y will not settlll!: on the innll!:r surface of the tubes, they will not affect the heat 11!:xchangll!:r performance.
- 4. Of the samples 11!:valuated in Rll!:ference 1, only 0. 1% of thll!: fiber population had a length of 0.39" or &rll!:ater. With this length, it is unlikely they could attach to thll!: innll!:r diam ll!:tll!:r of RH R hll!:at e>cchaneer tubes. Moreover, the fibers werll!: so fra&ile that any attem pt to dispersll!: thll!: clumps causll!:d e>ctensive brll!:akage of thll!: longll!:r fi bll!:r-5. Thesll!:
fiben also will bll!: easily swept away and carried out of the heat 11!:xchanger without affectin& heat Hchan1ll!:r pll!:rformancll!: . In summary, a rll!:vill!:w of heat exchanger performance concludll!:s that nonsolublll!:
i nsulation matll!:rial will not deteriorate the pll!:rfor mance of the as-built heat exchanger. Thi!: rust chips could present some potll!:ntiat effect to RHR heat exchanger performance. However, this concll!:m is minimized by the fact that a large fraction of the bi1&ll!:r chips are so thin that they will flow through the heat GEH Public Page 70 of 105 1
NED0-33878 Revision 3 Non-Proprietary Information - Class I (Public)
Component Mode of Operation Syltem / Component Flowrate Fluid Velocity thn.i Component System Oescriptk>ns and MiNion ~bri, ln1estion Model Wear Rate and Component Auxlllilry Equipment Evaklatlon ID Time Evaluation exchangers w hilll!: others will be broken into still smaller piecM by the rapid flow and therefore easily pass through the
- t-- heat exchanger. The key factors in heat exchanger performance an~ the routine maintenance, inspection, and cll~aning of the heat 11!:)(Changer. D@bris that pass through the ECCS suction strainers do not affect heat exchanger performance Therefore, there is no abnormal operiltional or safety concern with the identified debris on RHR heat exchanger performance, assuming they are property maintained.
f0048 Motor Operated (( (( )) (( The ECC5 piping / component flow area Control Valve exceeds the maximum dimension of the debris particles. Therefore, clouina: is not
)] considered credible.
))
FE-006B Flow Element (( (( )) (( The ECCS piping / component flow area exceeds the maximum dimension of the debris particles. Therefore, cloning is not
)) constdered credible.
))
D0048 Flow Restricting (( (( The ECC5 piping / component flow area
(( ))
Orifice exceeds the maximum dimension of the debris particles. Therefore, clogging is not
)) considered credible.
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NED0-33878 Revision 3 Non-Proprietary Information - Class I (Public)
Component Component Mode of Operatk>n System/ Component Ftownte Fluid Velocfty th,u Component System DescrlpUons a nd MiWOn ~bris ln1estion Modet Wear Rate and Component Auxiliary Equipment Evaluatlon ID Time Evaluation
))
FOOSB Motor Operated
(( The ECCS piping / component flow area Cont rol Valve
(( (( ))
exceeds the maximum dim ension of the
)) -- d@brls particles. Therdore, clogging is not considered credible.
))
fOOSSB Manual Block The ECCS pipin1 / component flow area
(( (( )) ((
Valve e,cceeds the maximum dimension of the debris particles. Therefore, clogging is not
)) consid@red cr@dible.
))
X-205 Penetration (( (( )) (( The ECCS piping / component flow are;i Hceeds the maximu m dime nsion of the debris partides. Therefore, clogging is not
)) considered credible.
))
GEH Public Page 72 of 105 1
NED0-33878 Revision 3 Non-Proprietary Information - Class I (Public)
Table A-6 : ECCS Suction Strainer Downstream Effects -Containment Spray w ith Heat Removal Mode E Component Component Mode of Operatk>n System / Component Flowrat e FluJd Velocity thru Component System Dttcriptlons and Mission Debris lncestlon Model Wear Rate and Component Auxllla ry Equ ipment Evaluat lon 10 Time Evaluation ECCS PIO ID ECCS (( It is assumed that settling will occur (( [The quantity of debris and makeup There are two types of wear of £valuation of Downstream Effects on Major
(( downstream of the stril iner needs to be Components components in when the flow velocity in the close runnin& cleil rilnces within t he flow p;ath to be process piping is less than the determined to assess wear rate of pump; 1) free-flowing abrasive The effects of debris passin1 through the strainers assessed settling veloclty for the debris type. pipina and components.) wear and 2) paddna-type abrasive on downstream components such as pumps.
wear. Wear within close-tolerance,
)) If settlin1 is not present, debris will )) Debris considered indudes fibrous hich-speed components is ii valves. ilnd heat exchilnaers hilS been evaluated remain in solution and not dog lines insulation debris and particulate debris as required under Rea Guide 1.82 Rev 4. This Determine flowrate at points in The ABWR ECCS m ission time for complex ilnalysis. The actual ilnd components. consisting of paint chips, concrete dust, evaluation includes assessina wear on surfaces system and use the flow/ velocity RH R post LOCA performance is 30 ilbnsive wear phenomenil will In the Safety Evilluation for WCAP* and reflectrle metilllic insulation shards exposed to the fluid stream due to various types to evaluate settling ilnd wear. dil'(S {720 houn). consistent with likely not be either a classk free-16406P (ML07352029S), the NRC smilll enough to pass throuch the holes of debris: e .a . pilint chips or RMI shards.
NRC auidance. Guidance in flowing or pildtina wear case, but ii
)) concluded thilt no settlin& of debris NUREG/CR-6988, "'Finill Report -
of the ECCS suction strainer perforated Evaluatina the potential for blockilge of smilH plates (1/8-inch diameter) . combination of the two. Both clearances due to downstream debris ilre also will occur in an instrument line Evaluation of Chemical Effects shou ld be considered in the installed above the horizont al pl;;ine In general, the ass umptions ilccount for included. The milterials and cleannces for the Phenomena in Post-LOCA Coolant," evilluation of their components.
of the process pipin1. Refere nce 42 particles larger than the screen opening valves. pumps. and heat exchangers downstream indicates t hat, although the of the ABWR ECCS suction strainers are essentially provides 1uidelines for locating size and ass ume iltl transportable Consider how wear of internal regulatio ns in 10 CFR 50.46(bl(S) process instrument connections material with the above dimensions or suffices of pump components will the same as the materials and cleuil nces for the require that Iona-term coolina be affect pump hydrilulic performance valves. pumps. and heat exchilngers downstream (tilps) on main process pipelines to maintained indefinitely ("for an Smi111er passes through the suction ensure thilt fittin1s on the bottom stniner unimpeded thus malCimizin& (total dynamic head and flow), the of the PWR containment sump suction stniners.
extended period of time"), 30-days of pipin& where th~ can collect the calculated particulilte and fibrous mechanical performance Therefore. Utilizing npects applied to PWR is typkally considered to be an crud ue avoided (Section debris concentrations in the post-LOCA (vibrationl, ilnd pressure boundary methodology for the ABWR is appropriate. (ref appropriate time period to S.3.3.LS.3). Therefore, ECCS process fluid . intearity (shaftseills). STPOCD6C.3 .2) demonstrate ECCS functionality and instrument lines ln servke during that, beyond this t ime, the decay The milXimum length of deformable Valve and heilt exchilnaer wetted post* LOCA operation are installed heat loading is small, making particulates that m ily pass throuah the materials should be evaluated for above the horlzontill plane of the alternative coolin& possible should penetrations (holes) in passive suction susceptibility to weilr, surface process pipinc. No settlinc of debris ECCS functionality be lost. strainers is equal to two times (2X) th e abrasion, and plugging. Weilr may in an instrument line in this maximum linear dimension of the alter the system flow distribution by orientation is expected. penetntion (hole) in the suction increil sin& How down a path The settlin& velocity for 2.S mil 55 strainer. (decreasina resistance caused by RMI is assumed to be 0 .4 ft/sec [ref wear), thus starvina ilnother critical The maximum width of deformable NEDO 32686 (URG)J pilth. Ot conversely, inaeased pilrticulates that may pass throu1h the resistance from pluuina of a valve A settlin1 velocity of 0.2 ft/ s was penetntions {holes) in pilssive suction openin&, orifice, or heat eKchanger assicned for pamt chips. Finally, ii strainers is equal to the maximum tube mily cause weilr to occur in settlin& velocity of 0.4 ft/s was linear dimension of the penetration ilnother path that experiences assigned to concrete dust and other (hole) in the suction stniner, plus 10 increased flow.
drywe ll puticulates. (ref NUREG CR percent (10%).
6224] Sludge/ corrosion prod. 200 lbm The malCimum thickness of deformable (density 324 lb/ ft3 per NEI 04* 07 A settlin& velocity for NUCON fibers puticulates that may pass throuah the Ti1ble4-2) used for preliminary assessment is penetrations (holes) in a passive suction 0 .2S ft/sec based on havin& lnorcanicZinc (IOZ) 47 lbm strainer is equill to one-half {1/2) the ceometry of partides that would (0.2516 ft3 per URG]
maximum linear dimension of the bypns the suction stniner. (ref penetration {hole) in the suction Epoxy Coated IOZ 85 lbm boundin& NU REG CR 6224 Table B-3 stniner. 0 .65 fr.3 per URG) ilnd NEI 04*07 Tilble 4*2] Rust Flakes 50 lbm The maximum cross-sectional area of deformable puticutates thilt may pass (324 lb/ ft3 per NEI 04-07 Table 4-2) through the penetrations (holes) in a passive suction strainer is equal to the Oust/ Dirt 150 lbm maximum cross-sectional now area of [156 lb/ ft3 per NEI 04-07 Table 4-2) the penetration {hole) in the suction Supp. Pool (SP) Initial Vol . (m in.)=
stra iner, plus 10 percent {l °"). 34SS m3 {Ref OCD T6.2* 2):: 3.4SS x The maximum dimension {lenath, width 1061iters.
and/or thickness) of non-deformable Assumin& the minim um SP volume particulates that mily pilSs throu&h ii and worst case debris volume, the suction strainer is limited to the cross* concentriltion of suspended solids GEH Public Page 73 of 105 1
NED0-33878 Revision 3 Non-Proprietary Information - Class I (Public)
Component Component Mode of Operat ktn System / Component Bow rate Fluid Velocity thru Com porwnt System Descriptions and Mission Debris lnce stlon Model Wear Rate and Component Aux il iary Equ ipment Evaluat lon 10 Time Evaluatlon sectional flow area of the penetration in the SP wa ter is estimated at 5130 (hole) in the suction strainer. ( WCAP* ppm by weight [0.07% vol.] for non*
016406} fiber debris and 6.8 ppm by weig ht The materials involved are relatively (0.018% vol.) fiber debris.
stiff and incom pressible and account for Under a realistic assumption of long, thin strands, of insulation being 4.3% of RMI passi ng through the able to pass through tight openings. ECC5 suction strainer, 218 ppm by It is assumed no settling of material weight [0.003% vol.] would exist in once in solution. The material wilt tend the SP volume.
to settle out in low flow areas in piping, Under a realistic assumption of 23%
the reactor vessel, the containment of NUKON fib ers passing through the floor, or hold-up volumes. ECCS suction strainer, 1.6 ppm by It is assumed the debris forms a weight [0.004% vol.) would exist in homogeneous solution at the start of the SP volume. Experimental data the event. on the effects of particulates on pump hydraulic performance applied to ECC5 type pumps show that pump performance degradation is neg ligible for particulate concentrations less than 1% by volume. [Ref: NU REG/C R 2792]
NUREG/C R 2792 notes conservative estimates of the nature and quantities of deb ris show that fine abrasives may be present in concentrations of about 0 .1% by vo lume (about 400 ppm by w eight).
and that very conservative @stimat@s of fibrous material yield concentrations of less than 1% by volume. Published data on the effects of particulates on pumps generally deal wi th particulate concentrations at many times these values.
U71 Containment ((
Orywetl Connecting Vents GEH Public Page 74 of 105 1
NED0-33878 Revision 3 Non-Proprietary Information - Class I (Public)
Comporwnt Component Mode of Operatk>n System / Component Aowrate fluid Velocity thru Component System Descriptions and Mission Debris lncestion Mode l W ear Rate and CompoMnt Auxllluy Equipment Evaluation ID Time Evaluation
))
Ell-01 RHR System The Emercency Core Cooling (ECC) DCD 531.3.2.3 Wiiter Quality and Materials of construction for ECCS Evaluiltion of Downstream EffKts on Miljor
(( (( ))
Systems are designed to withstand Submergence, provides rHctor water system components are listed in Components a hostile environment and still quality chuacteristics for the desian DCO Table 6.1-1 Encineered Safety The effects of debns passinc through the strainen
)) perform their function for 30 davs bHk LOCAs inside prffflary Features Component M,1terials. on downstream components such as pumps.
followinc an accident. contilinment.. valves. and heat exchilncers has been evaluated as required under Re1 Guide 1.82 Rev 4. This
(( (( ConsidMing an ECCS m ission time of 30 days (720 hrs.), the wear of evilluation includes assessing wear on surfaces components subjected to the debris exposed to the fluid stream due t o vuious types particles in solution (0.083 % SP of debris: e.1. pilint chips or RMI shilrds.
volume) is con sidered insienificant. Evaluating the potentlill for blockage of small clearances due to downstream debris ue also included. The materials and cleuances for the (ref: An Assessment of Residuill Heilt Villves. pumps. ilnd heat exchangers downstream Removal ilnd Containment Spray of the ABWR ECCS suction strainers are essentiillly Pump Performance Under Air and the same as the milteriats and deuilnces for the Debris tn1estin1 Conditions, NUREG/ Villves. pumps. ilnd heat exchangers downstream CR-2792) of the PWR contilinment sump suction strainers.
Therefore. Utilizin& i1Spects ilpplied to PWR methodolo1y for the ABWR is appropriate. (ref STP OCD 6C.3.2)
The RHR system has no t i&ht durance Villves throttled durmg post LOCA operation thilt would be susceptible to blocka1e or bindine. All RHR
)) valves in the post LOCA lineup will be dosed (i.e.
isolilte CST suction flow path) or fully open. As reflected on Tilble 1, Vatvi! Position Chart, on Figure S.4 -11, Residual Heilt Removal System PFD (Sheet 2 of 2), no RHR valves ilre throttled during post LOCA modes of operation . RHR m inimum flow is milintilined by ii piping orifice nther than throttlin& of the minimum flow valve.
RHR system check valves installed in the main RHR pump discharge tine, m inimum flow tine and jockey pump dischar1e line have active safety functions to open. These AHR valves are not susceptible t o clouin&, settling or weu. The clearilnces of these check valves prevent debris from adversely impactin& the functlOn of these
)) components. The check valve milteriat is carbon steel. Erosion or wear durin& the post LOCA credited 30-day mission time will not impact system performance.
RHR S'(1tem orifice plates ilnd SP and dryweH spu1ers installed in the RHR process pipin& have safety functions to mainta in flow. These RHR components are not susceptible to clouin&,
settlinc or wear. The cleuances of the se components prevent debris from adversely impacting the function of these components. The GEH Public Page 75 of 105 1
NED0-33878 Revision 3 Non-Proprietary Information - Class I (Public)
Compone.,t Component Mode of Oper* tlon System/ Component FWr*te Fk.l kt VeJodtythru Comf)OM'nt System Descriptions and Mfsslon , Debris lncestion Model Wea r Rate and Component Au,clllary£qu ipmfflt Evaluation 10 Time Evaluation orifice and sparger material is stainless steel.
Erosion or wear during the post LOCA credited 30*
day m ission tim@ wltl not impact system perform.11nce.
Debris size downstream ECCS SuctlOn 00018 Suction Strainer
(( (( )) ((
Strainer.
)) )) ((
The sizing of the RHR suction strainers conforms to the a:uidance of Reg Guide 1.82. The sizing is based on Siltisfying the NPSH requirements at runout flow, plus margin, with postulated piping insulation debris in th@ SP accumulated on the pump suction strainers. The sizing of the strainers is based on 30 days of post* LOCA operation.
RHR design has a provision for installation of a temporary strainer in each loop during pre-operational and startup testing.
Strainers are located to avoid air entrainment during a LOCA blowdown or from vortexing action and away from the safety relief valve quencher discharce zones.
Strainers shall be sized to prevent dogging of pump internal passages.
(Ret. 31113-0EU-2010 (Ref. 32})
))
X-202 Penetration The ECCS piping/ component flow area
(( (( )) ((
exceeds the maximum dimension of the debris particles . Therefore, clogging is
)) not considered credible.
))
FOOlB The ECCS piping/ component flow area
(( )) ((
exceeds the maximum dimension of the debris particles. Therefore, clogging is
)) not considered credible.
GEH Public Page 76 of 105 1
NED0-33878 Revision 3 Non-Proprietary Information - Class I (Public)
Component Component Mode of Operation System/ Component Rowrate Fluid Vefoctty thru Component System Descriptions a nd Missk,n Debris tncestion Model W ea r Rate a nd Component Auxiliary Equipmimt Evaluation ID Time Evaluation
))
C0018 RHR Pump B (( (( )) (( (( The ECCS piping/ component flo w area As described in NU REG /C R 2792, An NED0-32686 (URG) Vol 4 Evaluation of the Effects exceeds the maximum dimension of the Assessment of Residual Heat of Debris on ECCS Performance (GE-NE-T23*
debris particles. Therefore, clogging is Removal and Containment Spray 00700-15*21), addresses safety and operational
)) not considered credible. Performance Under Air and Debris concerns for failure of ECCS pumps associated Ingesting Conditions, concludes that with particles that pass through the ECCS suction under LOCA conditions with strainers.
generated debris at the pump, pump The ECCS pump design is coordinated with the performance degradation is ECCS suction strainer sizing to prevent dogging of expected to be negligible. In the pump interna l passages including mechanical seat event of shaft seal failure due to assemblies. The consequence of a plugged pump wear or loss of cooling fluid, sea l seal line would be high seal temperature and poor safety bushings limit leakage rates. sea11ife .
This is based on a debris concentration less than 0 .5% by
)) volu me. The ECCS pump includes a mechanical seal When considering long-te rm pump assembly with cydone particle separator and seal-opera tion and performance, it is cooling heat exchanger. A cyclone separator type of filtration is provided to maintain a dean cooling necessary to consider how wear of internal pump components will water supply to the seal.
affect the pump hydraulic
)) performance (total dynamic head The size of orifices used to control the flo w to and flow) , the mechanical ECCS pump seals is specified by the pump performance (vibration), and manufacturer to ensure the pump seal cooling pressure boundary integrity (shaft lines are not susceptible to plugging by debris not seals). The wear of the close running filtered by the cyclone separator type filter or clearances may affect the hydraulic debris larger than thi! seat cooling line orifice hole performance because of increased diameter.
internal or bypass leakage.
Wear rings and bushings are specifically designed Multistage pumps, designed fo r high (ha rd materials) to resist Wl!ar due to hard head service, usually operate at particulates in the process fluid . If the speeds above the first natural concentration of hard particulates is unusually frequency of the rotating assembly.
excessive, the effect could be a long-term The running clearances of the deterioration in the pump performance, in the suction side and discharge side of form of low pum p head . The requirement of 30 each impeller stage are designed days of post LOCA operation i~ not considered and manufactured to provide long-term .
hydrostat ic support and damping for the rotating assem bly, thus allowing operation at super-critical speeds Seat Faces without dynamic instability.
New seal face s are lapped to very flat and smooth Increasing the dose runn ing surfaces. The working gap between the faces is a clearances due to wear may reduce fraction of a micron. This means that large the overall shaft support stiffness at particulates would pass over the seal faces, and each impeller location, thus affecting would not enter the interface to destroy the the dynamic stability of the pum p.
smoothness of the face and cause lea kage.
Debris in the pumped fluid may affect the sealing ca pability of For the passive strainer with the holes sized at mechanical shaft seals. These seals 0 .125 in., little fiber is expected to pass t hrough are dependent on seal injection flow after the initial filter bed is formed . Little of the to cool the primary seal other debris (except for minimum sized iron O)(ide sludge) is expected to pass after the initial fi lter GEH Public Page 77 of 105 1
NED0-33878 Revision 3 Non-Proprietary Information - Class I (Public)
Component Component _ _ Mode of Operation System/ Component Flowrate FklidVelocitythn, CompoMnt Syttem Descriptions and Mission Debris lncestion Model Wear Rate and Component Auxiliary Equipmn1t Evaluation ID Time £valuation components. Dl!bris in the pumped bed precoat is formed . Therefore, all materials flow has the potential of blocking would most likl!dy pass through the orifice if 1% by the seal injection flow path or of volum e of fiber does not cause a highly unlikely limiting the performance of the seal "blitz" which plugs the orifice. Because all partides components due to debris buildup in arl! larger than a fraction of a micron, they would bellows and springs. These effects not l!nter the pump seal face. For shafts and may lead to primary seal failure. bushings, debris in quantities of onl! percent or Graphite safety bushings (disaster less of the pump fluid is likely to not constitute a bushings) may fail if exposed to high major thrl!at to the bushing integrity.
pressure fluid with debris following a primary seal failure ; thus, providing ((
an outside containment path for post- LOCA fluid .
((
))
))
GEH Public Page 78 of 105 1
NED0-33878 Revision 3 Non-Proprietary Information - Class I (Public)
Component Component Mode of Operation System / Component Flowrate Fluid Vetocfty thru Component System Descriptions a nd Mission Debris ln1estion Model Wear Rate and Component Auxllla ryEqulpment Evaluation ID Time Eva lua t ion ECCS pump performance for the specific plant as*
built configuration wit! r equire demonstration of acceptable performance under design conditions induding design debr is loading . Demonstration of acceptable performance for as-built ECCS pumps is validated under QME*l 2007, Qualification of Active Mechanical Equipment Used in Nuclear Power Plants as endorsed by RG 1.100, ~seismic Qualification of Electrical and Active Mechanical Equipment and Functional Qualification of Activl!
Mechanical Equipment for Nuclear Power Plants,"
Revision 3, September 2009.
F0028 Check Valve (( The ECCS piping / component flow area
(( )) ((
exceeds the maximum dimension of the debris particles . Therefore, clogging is
)) not considered credible.
))
F0038 Manual Block (( (( )) (( The ECCS piping / component flow area Valve exceeds the maximum dimension of the debris particles. Therefore, clogging is
)) not considered credible.
))
B001B Heat Exchanger (( (( )) (( The RHR heat exchanger tube ID is NED0* 32686 (URG) Vol 4 includes evaluation of 17.22 mm . The ECCS strainer will ECCS heat exch angers:
restrict debris to less than 3.18 mm . This assessment was adjusted for the ABWR RHR
)) Therefore, the RHR heat exchanger will heat exchanger with suppression pool water not become dogged from debris flowing though the tubes of the heat exchanger.
passing downstream of the ECCS As described in ABWR DCO section S.4.7.1, the suction strainer. ABWR RHR heat exchanger has taken advantage of a design change that was made with respect to prior BWRs. ABWR has the reactor water flowing through the tube side of the heat exchanger, whereas, prior BWRs had the reactor water flowing through the shell side. The primary purpose for the change was to reduce radiation
]) buildup in the heat exchanger by providing a more open geometry flow path through the center of the tubes, as opposed to the shell side construction of spacers, baffles, and low flow velocity locations, which can provide places for radioactive sludge to accumulate.
Heat Exchangers GEH Public Page 79 of 105 1
NED0-33878 Revision 3 Non-Proprietary Information - Class I (Public)
Component Component Mode of Operation Syste m / Component F~rate flu kl Velocity thru C'.omponent Syste m OeKtipUons a nd Mission Debris lncestion Mode l Wear Rate a nd Component Auxiliary Equipment Evaluatfon 10 Tim e Evaluat ion Significant effect on RHR heat exchanger performance can occur if a targe quantity of debris is retained inside the hl!at elCchangers causing blockage of the flow and / or fouling of the tubes.
Flow from the suppression pool is channeled through the tubl! side of the RHR heat exchangMs.
The tube side flow velocity of a RHR heat exchanger Is approximately 2 fV sec. At this velocity, the How will entrain thl! small particles without allowing them to settle in the hl!at exchanger. The tube site is 0 .68 Inch d iameter.
The rHults of the size distribution analys@s ar@
evaluated as follows:
- 1. Th@ rust chips ar@ th@ largMt, but ar@ Vl!:ry lik@ly to br@ak into smaller pieces. Considering the possibility that th@ larg@st chips get through the strainer holes and through the pumps without being brok@n up, (not considered credible), will pass through th@ h@at @xchanger tubes. Iron oxide (Fe20 J or FeJO*l will not ,promote oxidation and corrosion on the inside diamet@r of th@
staint@ss st@@I tubes. Therefore, rust debris particles will not contribute to fouling and/ or thinning of the tubes.
- 2. Epoxy paint chips are small and light @nough that th@y will be swept through th@ heat e)(changers, and are of no concern .
- 3. The size of the sand crains are small enouch that it is unlikety that they will be captured along the flow path, but may be h@avy @nough to settle in pockets of low velocity near the tube sheets of the heat exchanger. Because they will not settl@
on the inn@r surhce of the tubes, they will not affect the heat exchang@r performance.
- 4. Of the samples evaluated in Reference 1, only 0 .1% of the fiber population had a length of 0.39" or greater. With this length, it is unlikely they could attach to the inner diameter of the RHR heat e)(changer. Moreover,.the fibers were so fragile that any attempt to disperse the clumps caused e)(tensive breakage of the longer fibers.
These fibers also will be easily swept away and carried out of the heat exchang@r wi thout affecting heat exchanger performance. In summary, a review of heat exchanger performance concludes that nonsoluble insulation material wrll not deteriorate the performance of the as*built heat exchanger. The rust chips could present some potential effect to RHR heat
@xchanger performance. However, this concern is minimized by th@ fact that a large fraction of the bigger chips are so thin that they will flow through the heat exchangers whil@ others will be broken into sti11 smaller pieces by th@ rapid flow and th@refor@ @asily pass through the heat e)(changer.
The key factors in heat exchanger performance GEH Public Page 80 of 105 1
NED0-33878 Revision 3 Non-Proprietary Information - Class I (Public)
Component Component Mode of Operation System/ Component Flowrate Ftuld Velocity thru CompoMnt System DescripUons and Mission Debris lncestion Model Wear Rate and C.Omponent Auxlllary Equlpm~t Evailuatfon ID Time Evaluation are the routine maintenance, inspection, and cleaning of the heat e>tchanger. Debris that pass through the ECCS suction stra iners do not affect heat t!xchanger performance Therefore, there is no abnormal operational or safety concern with the Identified debris on RHR heat exchanger perform,o1nce, assuming they are properly maintained .
F004B Motor Operated The ECCS piping/ component now area
(( (( )) ((
Control Valve exceeds the maximum dimension of the debris particles. Therefore, clogging is not considered credible.
))
))
FE-0068 Flow Element
(( (( )) (( The ECCS piping / component ftow area exceeds the maximum dimension of the debris particles. Therefore, dogging is not considered credible.
))
))
FE-015 8 Flow Restricting (( (( )) (( The ECCS piping/ component ftow area Orifice exceeds the maximum dimension of the debris particles. Therefore, dogging is not considered credible.
))
GEH Public Page 81 of 105 1
NED0-33878 Revision 3 Non-Proprietary Information - Class I (Public)
Component Component Mode of Operat ion System/ Compone nt Aowrate Fk.lMI Velodty thru Componttnt System Descriptions and M lssk>n Debris ln,estion Model Wea r Rate a nd Component Auxilla ry Ecp., ipmrnt Evaluation 10 Time Evaluation
))
F0198 Motor Operated (( (( The ECCS piping/ component flow area
(( ))
Block Valve exceeds the maxim um dimension of the debris particles. Therefore, dogging ls
)) not considered credible.
))
F056B Manual Block
(( The ECCS piping/ component flow area
(( )) ((
Valve e,cceeds the maximum dimension of the debris particles. Therefore, clogging Is
)) not considered credible.
))
X*200A Penetration (( (( )) (( The ECCS piping/ component flow uea exceeds the maim um dimension of the debris particles. Therefore, clogging is
)) not considered credible.
))
0010 WetwellSprav (( (( The ECCS piping / component ftow area
(( ))
Spilrgers exceeds the maximum dimension of the debris particles. Therefore, clogging is
)) not considered credible.
GEH Public Page 82 of 105 1
NED0-33878 Revision 3 Non-Proprietary Information - Class I (Public)
Component Component MOCM of Operation System / Component Flowrate Flu kt Vefodty t hru Com~nt System OeacripUons and MIHion Debris ln,estion Model Wear Rate and Component Auxlllary Equ~ment Evalu.tton ID Time Evaluation
])
F017B Motor Openited (( )) ((
((
Block Valve
))
))
F0188 Motor Operated (( (( )) ((
Block Valve
))
))
Penetration X30A (( (( ]) ((
))
))
0009 Orywell Spray (( (( )) ((
Spar1ers
))
GEH Public Page 83 of 105 1
NED0-33878 Revision 3 Non-Proprietary Information - Class I (Public)
Component Component Mode of Oper*tion System / Component Flowrate Fluid Vetodty thN CompoMnt System Descriptions and Miuion Debris lnsestion Model We*r Rate and Component Au>elllaryEquipment Evalu.tton 10 Tim< £valuation
))
GEH Public Page 84 of 105 1
NED0-33878 Revision 3 Non-Proprietary Information - Class I (Public)
Table A-7 : ECCS Suction Strainer Downstream Effects-High Pressure Core Flooder Mode 81 Component Com ponent Mode of Operation System/ Component Flowrate flukf VeJoclty thru Component System Dffcriptions and Mission Debris l11Cffllon Model Wear Rate and Component Au,clllaryEquipment Evaluation 10 Time Evaluation ECCS PIO ID ECCS (( It is assumed that settling will occur [The qua nt ity of debris and makeup There ue two types of wear of dose ((
((
componen ts in when the flow velocity in th e process downstream of the strainer needs to be runnin& dea rances within the pump; flow path to be pipina: is less than the settling velocity determined to assess weilr nte of pipin1 1) free-flowin1 abrasive wear and 2) assessed for the debris type. )) and components.) packin&*type abrasive wear. Wear If se:ttlin1 is not present, debris will The ABWR ECCS mission time for Debris considered indudes fibrous within dose-tolerance, high-speed
)) remain in solution and not do1 lines HPCF post LOCA performance is 30 insulatton debris ilnd particulilte debris components is a complex analysts.
Determine flowrate at points in and components. days (720 hours0.00833 days <br />0.2 hours <br />0.00119 weeks <br />2.7396e-4 months <br />), consistent with consisting of paint chips, concrete dust, The actual abrasive wear phenomena system ilnd use the flow/ velocity to NRC guidance. Gu idance in ilnd reflective metilllk lnsuliltion shards will likely not be either ii classic free-Under the Safety Evaluation for flowing or packin1 wear case, but a
)) evaluate settlin& and wear.
WCAP-16406P (ML07352029S), the NUREG/ CR-6988, "Final Report - smilll enough to pass throueh the holes of combiniltion of the two. Both should Evaluat ion of Chemical Effects the ECCS suction strainer perforated NRC conduded that no settling of Phenomena in Post -lOCA Coolant,"' plates (1/8-inch diameter). be considered in t he evaluation of debris will occur in an instrument line their components.
indicates that, although the installed above the horizontal plane regulations in 10 CFR S0.46(b)(5) (( Consider how wear of Internal
))
of the process pipin1. Reference 42 require that long-term cooling be surfaces of pump components will provides 1uidelines for locilting ma int ained lndefin ltely ("for an affect pump hydraulic perform ance process instrument connections extended period of time" ), 30-days (total dynamic head and flow), the (taps) on main process pipelines to is typically considered to be an mechanical performance (vibntion),
ensure that fittin1s on the bottom of appropriate time period to and pressure boundary integrity pipin& where they can collect crud demonstrate ECCS functlona llty and (shaft seals).
are avoided [Section 5.3.3.1.8.3.
that, beyond this time, the decay Therefore, ECCS instrument lines in heat loading is small, making
)) Valve and heat exchan1er wetted service durin& post-lOCA operation materials should be evaluated for alternative cooling possible should The maximum length of deformable are installed above the horizontal susceptibility to wear, surface ECC5 functional ity be lost. particulates tha t may pass throu1h the plane of the process piping. No abrasion, and pluggin&. Wear may penetrations (holes) in passive suction settlln& of debris in an instrument alter the system flow distribution by strainer is equal to two times (2X) thl!:
line in this orientation is expected. increasin1 now down a path maximum lineu dimension of the The settlln1 velocity for 2.5 mil 55 (decreasin1 resistance caused by penetratK>n (hole) in the suction strainer.
RMI is assumed to be 0.4 ft/sec [ref wear), thus stilrvin1 another critical The maximum width of deformable path. Or conversety, increased NEDD 32686 (URGI]
puticulates that may pass throueh the resfStance from pluuin& of a valve A settlin& velocity of 0.2 ft/ s WilS penetrations {holes) in passive suction openin&, orifice, or heat exchanger assi1ned for paint chips. Finalty, a strainer is eqUill to the maximum linear tube may cause wur to occur in settlin& velocity of 0.4 ft/s was dimension of the penetration (hole) in ilnother path that experiences assi&ned to concrete dust and other the suction strainer, plus 10 percent increased flow .
drywell particulatl!:s. !ref NUREG CR (1<)%} .
6224) Sludge/ corrosion prod. 200 lbm The maxim um thickness of deformable (density 324 tb/ft3 per NEI 04-07 A settlin1 velocity fo r NUCON fibe rs particulates that may pass through the Ta ble4-2J used for preliminary assessment is penetrations {holes) in a passive suction lnorgank Zinc (IOZ) 47 tbm 0.25 ft/sec based on having 1eometry strainer is eq ual to one-half (1/2) the (0.2516 ft3 per URG) of partides that would bypass the maxim um linear diml!:nsion of the suction strainer. !ref bounding Epoxy Coated IOZ 85 lbm penetration {hole) in the suction strainer.
NU REG CR6224 hble B-3 and NEI 04* 0.65 ft3 per URG) 07 Table 4-2) The maximum cross-sectional area of Rust flakes 50 lbm deformilble particulates that may pass (324 lb/ft3 per NEI 04-07 Table 4-21 through the penetrations (holes) in a passive suction strainer is equal to the Oust/ Dirt 150 lbm [156 milximum cross-sectionill flow area of the lb/ft3 per NE I 04*07 Table 4-21 penetration (hole) in the suction strainer, Supp. Pool (SP) Initial Vol. (min.)=
plus 10 percent (10%). 3455 m3 (Ref DCO T6.2-2)::: 3.455 x The maxi'num dimension {1en&th, width 106 liters.
and/or thickness) of non-deformable Assumin1 the minimum SP volume particulates that may pass through a and worst case debris volume, the suction strainer is limited to the cross* concentration of suspended solids in sectional flow area of the penetration the SP water is estimated at 5130 ppm by weicht ro.07% vol.) for non-GEH Public Page 85 of 105 1
NED0-33878 Revision 3 Non-Proprietary Information - Class I (Public) eom,,onont Component Mode of Operation System / Component Flowrate Ftuld Velocity thru Component System Descriptions and Mission Wear Rate and Component AuxlllaryEquipment Evaluation 10 Time EvatuaUon (hole) in the suction strainer. I WCAP* fiber debris and 6.8 ppm by weight 016406) (0.018" vol.) fiber debris.
The materials involved are relatively stiff Under a realistic assumption of 4.3%
and incompressible and account for lon1, of RMI passing through the ECCS thin strands, of insulation being able to suction strainer, 218 ppm by weight pass through tight openings. (0.003" vol.) would exist in the SP It is assumed no settlin1 of material once volume.
in solution. The material will tend to Under a realistic assumption of 23" settle out in low How are;as in pipin&, the of NUKON fibers passinc through the ructor vessel, the containment floor, or ECCS suction strainer, 1.6 ppm by hold*UP volumes. wei&ht [0.004" vol.) would exist in It is .usumed the debris forms a the SP volume.
homogeneous solution at the st.ut of the Experimental data on the effects of event. pa rticulates on pump hydraulic performance applied to ECCS type pumps show that pump performa nce degradation is ne1li1ib1e for particulate concentrations less than 1% by volume. (Ref: NU REG/CR 2792)
NUREG/CR 2792 notes conservative estimates of the nature and quantities of debris show that fine abrasives may be present in concentrations of about 0 .1% by volume (about 400 ppm by weight).
and that very conservative estimates of fibrous material yield concentrations of less than 1% by volume. Published data on the effects of particulates on pumps cenerally deal with particulate concentrations at many times these values.
U71 Containment ((
Drywell Connecting Vents
))
GEH Public Page 86 of 105 1
NED0-33878 Revision 3 Non-Proprietary Information - Class I (Public)
Component Component Mode of Op...-tlon System/ Component Flowl'llte Fluid Ve'oclty thru Component System Descriptions and Mfssio n Debris lnsestton Model Wear Rate a nd Component Auxll laryEquipment Evaluation ID Time Evaluatktn
£22-01 HPCF System The Emergency Core Cooling (£CC) DCD S31.3.2.3 Water Quality and Materials of const ruction for ECCS Evaluation of Downstream Effects on Major
(( (( )) Subm ergence, provides reactor water Components Systems are designed to withstand a system components ilre listed in OCD hostile environment and still perform quality characteristics for the design basis Table 6.1* 1 Engineered Safety Both the HPCF and RCIC systems take
)) their function for 30 dilys following an LOCAs inside primary containment. Futures Component Materia ls. primary suction from the CST and secondary accident." Considering an ECCS mission time of suction from the suppression pool (SP). The
((
30 days (720 hrs.), the wear of CST is clean demineralized water free of JL components subjected to the debris debris. This assessment assumes most partkles In solution (0.083 % SP conservative alignment from the SP source.
vol ume) is considered insig nificant. The effects of debris passing through the (ref: An Assessment of Residual Heat strainers on downstream components such Removal and Containment Spray as pumps. valves. and heat exchangers has Pump Performance Under Air and been evaluated as required under Reg Guide Debris Ingesting Cond itions, NUREG/ 1.82 Rev 4 . This evaluation includes CR* 2792) assessing wear on surfaces exposed to the fluid stream due to var'ious types of debris:
e .g. paint chips or RMI shards. Evaluating the potential for blockage of small dearances
)) due to downs tream debris are also induded.
The materials and clearances for the valves.
pumps. and heat exchana;ers downstream of the ABWR ECCS suction strainers are essentially the same as the materials and clearances for the valves. pumps. and heat exchana;ers downstream of the PWR containment sump suction strainers.
Therefore. Utilizing aspects applied to PWR methodology for the ABWR is appropriate.
(refSTP OCO 6C.3.2)
The HPCF system has no tight clearance valves throttled durin& post LOCA operation that would be susceptible to blockage or
)) bindinc. All HPCF valves in the post LOCA lineup will be closed (i.e . isolate CST suction flow path) or fully open. As reflected on Table 1, Valve Posit ion Chart, on Figure 6.3-1 High Pressure Core Flooder System PFO (Sheet 2 of 2), no HPCF valves are throttled during this mode of operation . HPCF minim um flow is maintained by a piping orifice rather tha n throttling of the m inimum flow valve.
HPCF system check valves installed in the main HPCF pump suction, discharge and minimum flow line have active safety functions to open. These HPCF valves are not susceptible to clo11in1, settling or wear. The clearances of these check vatves prevent debris from adversely impacting the function of these components. The check valve material is carbon steel. Erosion or wear during the post LOCA credited 30-day mission time will not impact system performance.
GEH Public Page 87 of 105 1
NED0-33878 Revision 3 Non-Proprietary Information - Class I (Public)
Component Component Mode of OpenHon System/ Component Fbwrate Fluld Vek>clty t hN Component System Descriptions and Mlssk>n ~bris ln,estion Model Wear Rate and Component Auxilia ry Equipment Evaluation 10 Time E~luaUon 0003 B Suction Strainer ([ Debris size downstream ECCS Suction
(( )) ((
Strainer.
)) ))
The muim um dimension {len1th, width The sizin1 of the HPCF suction and/or thickness) of non*deformable strainen; conforms to the 1uidance of particulates that may pass throu1h the Re& Guide 1.82. The sizin& is based on strainer is limited to the cross*sfflional utisfyinc the NPSH requirements at flow area of the penetration {hole) In the runout flow, plus mu1in, with strainer.
postulated pipin& insuliltion debris in the SP ac;com ulated on the pump suctK>n stniners. The sizin& of the len&th = 0.24 inch strainers is based on 30 days of post* Width= 0.132 in.
LOCA operation.
Thickness =0.060 in.
HPCF design has a provision for installation of a temporary striliner in Cross Section Area= 0 .0123 in2 each loop during pre* operiltional and startuptestin&, The design debris source term Strainers are located to avoid air downstream the ECC5 suction strainer is:
entrainment during a LOCA blowdown or from vortexing iidion .ind ilway NUKON 51.6 lbs (assume all NUKON from the safety relief valve quencher passes through strain@r) RMI 38,500 dischar1e zones.
lbs. (Assum@ all RMI passes through Strainers shall be sized to prevent strainer) clo11inc of pump internal passages.
(Ref: 31113-0f22* 2010 (Ref. 33)]
Sludge/ corrosion prod. 200 lbm lnorcanic Zinc (IOZ) 47 lbm Epoxy Coated IOZ 8Slbm Rust Flak@.s SOlbm X* 210 Pen@tration (( ((
.- )) [(
Oust/Dirt 1S0lbm The ECC5 piping/ component flow area
@xceeds the maximum dimension of the d@bris particles. Therefore, cloccinc Is not
)) considered credible.
))
F0068
(( )) (( Th@ ECCS piping / component flow area exceeds the maxim um dimension of the debris particles. There fore, dogging is not
)) considered credible.
))
GEH Public Page 88 of 105 1
/
NED0-33878 Revision 3 Non-Proprietary Information - Class I (Public)
Component Component Mode of Operat ion System/ Component Ftowrate Flu id Velocity thru Component System Descriptions and Mission Debris tncestlon Model Wear R* te a nd Component AuxlllaryEquipment Evaluation ID Time Evalu1t lon f0078 Check Valve The ECCS piping/ component flow area
(( (( )) ((
e>cceeds the maximum dimension of the debris particles. Therefore, clogging is not
)) considered credible.
))
(0018 HPCF Pump 8
(( (( )) (( (( The ECCS piping/ component flow area As described in NU REG /CR 2792, An NED0-32686 (URG) Vol 4 Evaluation of the exceeds the ma11:imum dimension of the Assessment of Residual Heat Removal Effects of Debris on ECCS Performance (GE-debris particles. There.fore., clogging is not and Containment Spray Performance NE-T23-00700-15-21), addresses safety and
)) considered credible. Under Air and Debris Ingesting operationa l conce rns fo r fail ure of ECCS Conditions, concludes that under pum ps associated with particles t hat pass LOCA conditions with generated through the ECCS suction strainers.
debris at the pump, pump The ECCS pump design is coordinated with performance degradation is Hpected the ECCS suction strainer sizing to prevent to be negligible. In the @vent of shaft clogging of pump internal passages including seal failure due to wear or loss of mechanical seat assemblies. The cooling fluid, seal safety bushings limit consequence. of a plugged pump seal line teak.age rates. This is based on a would be high seal temperat ure and poor debris concentration less than 0.5% by seal life.
)] volume.
The ECCS pump includes a mechanical seal When considering long-term pump assembly with cyclone particle separator and operation and perfo rmance, it is seal-cooling heat e11:changer. A cyclone
)) necessary to consider how wear of separator type of filtration is provided to internal pump components will affect maintain a clean cooling water supply to the the pump hydraulic performance seal (total dynamk. head and now), the mechanical performance (vibration), The size of orifices used to control the flow and pressure boundary integrity (shaft to ECCS pump seals is specified by the pump seals). The wear of the close running manufacturer to ensure the pum p seal clearances may affect the hydraulic cooling lines are not susceptible to plugging by debris not filtered by the cyclone performance be.cause of increased separator type filte r or debris la rger than the internal or bypass leakage. Multistage pumps, designed for high head seal cooling line orifice hole diameter.
servlCe, usually operate at speeds Wear rings and bushings are specifically above the first natural frequency of designed (hard materials) to resist wear due the rotating assembly. The running to hard particulates in the process fluid . If clearances of the suction side and the concentration of hard particulates is discharge. side of each impeller stage unusually excessr\fe, the effect coo Id be a are designed and manufactured to long-term deterioration in the pump provide hydrostatic support and performance, in the form of low pump head.
damping for the rotating assembly, The requirement of 30 days of post LOCA thus allowing operat ion at super* operation is not considered long-term.
critical speeds without dyna mic instability. Increasing the close Seal Faces running clearances due to wear may reduce the overall shaft support New seal faces are lapped to very flat and stiffness at each impeller location, smooth surfaces. The working ga p between thus affecting the dynamic stability of the faces is a fraction of a micron. This the pump. Debris in the pumped fluid me.ans that large particulates would pass may affect the sealing capability of over the seal faces , and would not enter the mechanical shaft seals. These seals GEH Public Page 89 of 105 1
NED0-33878 Revision 3 Non-Proprietary Information - Class I (Public)
Component Component Mode of Operation System / Component Flowrat e Flukt Veb:lty thN Component System Descriptions and Missk>n Debris lntfflion Model Wear Rate and Component Auxlllary Equ ipment Evaluation ID Tim e Evaluation are dep@ndent on s@a1 injection flow intl!:rface to destroy thl!!! smoothness ofthl!!!
to cool the primary seal components. face and cause leakage.
Debri s in the pumped flow has the potential of blodc.ing the seal i njection For the passive strainer with the holes sized flow pa th or of limiting the at 0.125 in ., little fiber is expected to pass performance of the sea l components through after thl!!! initial filter bed is formed, due to debris buildup in bellows and and also littll!!! of the other debris (except for springs. These effects may lead to minimum sized iron oxide sludge) is primary seal failure. Gr.;iphite safety expected to pass after thl!!! initial filter bed bushings (disaster bushings) may fail if prl!!!coat is formed. Therefore, all materials exposed to high pressure fluid with would most likely pass through the orrftce if debris following a primary s@al failure 1% by volume of fiber does not cause a thus, providing an outside highly unlikely "blitz" which plugs the o rifi ce.
containment path for post-LOCA fluid .
Because all particles are larger than a ECCS pump rotor dynamics changes fraction of a micron, they would not enter and long-term effects on vibrations the pump seal face. For shafts and bushings, caused by potential wear are debris in quantitll!!!s of one percl!!!nt or less of reviewed in the context of rotating thl!!! pump fluid is likl!!!ly to not constitute a equipment operability and reliability. major threat to the bushing integrity.
Based on AP1*6 10, a wear limit of2X as*new values is generally applied for
((
pumps not analyzed (2X limit). It is expected that ECCS pumps operated for 30 days (720 hrs.) under modes of operation assessed and pumping liquid at maximum suspended solids will not wear to a point when!
vibration will affect operability.
GEH Public Page 90 of 105 1
NED0-33878 Revision 3 Non-F'roprietary Information - Class I (Public)
Component Mode of Operat ion System/ Component Flowrate Fluid VdOclty thN Component System Dffcriptions i nd Mfssk>n Debris lncestlon Model Wear Rate and Component Auxiliary Equipment Evaluation
'°"""'"""'
ID Time EvaluaUon
))
ECCS pump performance for the specific plant as-built configuration will require demonstriltion of acceptabl@ performanc, under design conditions including design debris load inc. Demonstration of acceptable performance for as.built ECCS pumps is validated under QME-12007, Qualific.ition of Active Mechanical Equipment Used in Nuclear Power Pl;1nts as endorsed by RG 1.100, "Seismic Qualification of Electrical and Active Mechanical Equipment and Functional Qualification of Activll! Mechanical Equipment for Nuclear Power Plants, "
Revision 3, September 2009.
F021B Check Valve (( The ECCS piping/ component flow area
(( (( ))
exceeds the maximum dimension of the debris partides. Therefore, do11in1 is not
)) considered credible.
))
FE-0088 Flow Element The ECCS piping/ component now area
(( (( )) ((
exceeds the maximum dimension of the debris partick!-s. Therefore, do11in1 is not
)) considered credible.
GEH Public Page 91 of 105 1
NED0-33878 Revision 3 Non-Proprietary lnforma~i on - Class I (Public)
Component Component Mode of Operation System / Component Fbwrate Fluid Veklctty thru Component --System Descriptions and M fsston Of!bris tnce-stlon Model Wear Rate and Component AUJclllaryEqulpment Evaluation 10 Time EvaluaUon
))
00028 Flow Restricting (( The ECCS piping / component flow are.i
(( )) ((
Orifice exceeds the maxim um dimension of the debris particle s. Therefore, clogging is not
)) considered credib le.
))
f0038 Motor Operated (( (( )] (( The ECCS piping / com pon@nt flow area Bk>ck Valve exceeds the muimum dimension of the de bris particles. Therefore, clogging is not
)) considered credible.
))
Penetration The ECCS piping / component flow area X* 31A
(( (( )) ((
@xceeds the maximum dimension of thl!
debris particles. Ther@forll!:, clogg ing is not
)) considered credible.
))
f0048 Che:ck Valve (N2 (( (( )) (( The ECCS piping / component flo w area Testable ) e11:ceeds the muimum dimension of the debris particles. Therefore, clogging is not
)) considered credible .
))
FOOSB M;rnual Block (( )) (( The ECCS piping/ component flow area
((
Valve exceeds the maximum dimension of the debris particles. Therefore, clogg ing is not
)) considered credib le.
GEH Public Page 92 of 105 1
NED0-33878 Revision 3 Non-Proprietary Information - Class I (Public)
Component Component Mode of Operation System/ Component Fbwrate Flukl Vetoclty thru Com ponent System Descriptions and M~1ion Debris lncNUon Model Wear Rate and Component AuxlllaryEqu ipment Evaluation 10 Time Evaluation
))
Reactor HPCFSpar1ers (( (( The ECCS piping/ component flow area
(( ))
Internals exceeds the muimum dimension of the (Reactor debris partides. Therll!fore, cto11in1 is not Pressure )) considered credible.
Vessel 811)
))
Reactor The high pressure conficuration The reactor vesse:I flow ue,1 orifices Reillctor
(( (( ))
Internals Assembly consists of two motor driven hi&h exceed the maximum dimension of the (Reactor pressure core flooders (HPCF) each debrts partkles. Therefore, clogging is not Pressure )) with tts own independent sparger considered aedibte.
Vessel Bll) dischar1in1 inside the shroud .
The ECCS flow with debris is injected inside the shroud and travels through annulus between core support plates and shroud to the fuel inlet throueh the holes in the lower tie plate, 1ettin1 collected in the lower tie plate 1rld/ filter. Also, once the in-shroud level reaches the normal water level in the steam separators and spills into the RPV annulus, the debris will be mixed in the lower plenum and enter through the inlet orifice.
Flow is also available to the fuel assemblies th roueh the upper tie pla tes. fro m HPCF spray. The only way that flow will be downward from upper pl@num thru upp@r tie plate is if the lower tie plate filter becomes excessively blocked . (ABWR doesn' t uncover upper core like older BWRs that can allow spray into top before inlet beCOmes fully plugeed).
Downward flow repres@nts a nearly fulty blocked inl@t filter (allowine less than S" normal flow, .an inause in inlet resistance of X400).
Jll Fuel (( The ABWR ev.aluation uamines the
(( ))
Assembly effects of bundle inlet douine th.at reduces the availabl@ inlet flow from
)) n.at ural circulation phenomena following init i.al core r@fill when th@
- core r@gion is cover@d by a two-phase mixture. Durine this post-LOCA GEH Public Page 93 of 105 1
NED0-33878 Revision 3 Non-Proprietary Information - Class I (Public)
Component Component Mode of Operation System/ CompoMnt Flowrate Fluid VekJclty thn, Component Svstem Descriptions and MiHk>n Debris tncestk>n Model Wear Rate and Component AuxlllaryEquipment £valuation 10 Time Evaklatio n period, the reduced inlet flow results in increased bundle voiding and higher velocities such that the hut transfer is sufficient to remove the decay heat. Once the bundle decay heat has decrl!ased and insufficient voids exist to ma intain the level in the bundle above the top of the fuel channel, adequate cooling from the upper plenum spillover will exist .
Thus, the evaluatio n concludes that fouignificant bundle inlet dogging following initial core refill, BWR fuel bundle cootin&: is assured .
GEH Public Page 94 of 105 1
NED0-33878 Revision 3 Non-Proprietary Information - Class I (Public)
Table A-8 : ECCS Suction Strainer Downstream Effects-Reactor Core Isolation Cooling System Mode C Component CompoMnt Mode of Operation System/ Component Ftowrate Fluid Velocity thru Component System Descriptions and Mission Time Debris lna:estion Model Wear Rate and CompoMnt AuxillaryEquipment Evaluation 10 Evaluatton ECCS PIO ID ECCS components It is usumed that settlin& will occur [The quantity of debris and maket1p There are two types of wear of close
(( (( (( Evaluation of Downstream Effects on in flow path to be when the flow velocity in the process downstream of the strainer ne~s to be n.mninc clearances within the pump; Major Components assessed piping is less than the settling velocity determined to assess wear rate of piping 1) free-Howin& abrasive wear and 2) The effects of debris passinc through for the: debrb type. ]) and components) packin1-type abrasive wear. Wear the strainers on downstream lf settlin&is not present, debris will The ABWR £CC5 mission time for RCIC Debris considered includes fibrous within close-tolerance, hieh-speed components such as pumps. valves. and
]) post LOCA performance is 12 hours1.388889e-4 days <br />0.00333 hours <br />1.984127e-5 weeks <br />4.566e-6 months <br />. components is a complex analysis.
remil in in solution and not doc lines insulation debris and particulate debris heat exchangers has been evaluated as Determine flow rate at points in and components. consistent with ABWR OCO Table 3.11* consisting of paint chips, co ncrete dust, The actual abrasive wear phenomena required under Reg Guide 1.82 Rev 4.
system and use the flow / velocity to 2 for environmental qualifiCiiltion. and reflective metallic insulation shards will likely not be either a classic free- This evaluation includes assessin& wear In the Safety Evaluation for WCAP-
)) evaluate settling and wear.
16406P (Ml073520295), the NRC small enough to pass throuch the holes of flowinc or packin1 wear case, but a on surfaces exposed to the fluid stream the ECCS suction strainer perforated combination of the two. Both should due to various types of debris: e .1.,
concluded that no settling of debris will plates (1/8-inch dia meter) be considered in the evaluation of pa int chips or RMI shards. Evaluating occur in an instrument line installed their components. the potential for blockace of sm all above the horizontal plane of the In ceneral, the assum ptions account for process pipinc. Reference 42 provides partides lar1er than the screen Conlider how wear of internal clearances due to downstream debris guidelines for locating process surfues of pump components will are also included . The materia ls and opening size and assume an transportable instrument connections (taps) on main _ _ affect pump hydraultc performance clearances for the valves. pumps. and material with the above d imensions or process pipelines to e nsure that fittincs (total dynamic head and flow), the heat exchancers downstream of the smaller passes through the suction on the bottom of piping where they can mechanical performance (vibration), ABWR ECCS suction strainers are strainers unimpeded thus maKimizing the collect crud are avoided (Section and pressure boundary intecrity {shaft essentially the sa me as the materials calculated particulate and fibrous debris S.3.3.1.8.3). Therefore, ECCS seals). and clearances for the valves. pum ps.
concentrations in the post-LOCA process instrument lines in service during post- Valve and heat exchancer wetted and heat exchangers downstream of the fluid .
LOCA operation are installed above the materials should be evaluated for PWR containment sump suction The maximum length of deformable strainers. Therefore. Uttlizin& aspects horizontal plane of the process pipinc. susceptib ility to wear, surface particulates that may pass throuch the applied to PWR methodolocy for the No settling of debris in an instrument ab rasion, and plu11in1. Wear may penetrations {holes) in passive suction ABWR is appropriate. [ref STP OCO line in this orientation is expected . alter the system flow distribution by strainer is equal to two times {2X) the 6C.3 .2J The settling velocity for 2.5 mil 55 RMI increasinc flow down a path maximum linear dimension of the is assumed to be 0 .4 ft/sec (ref NEOO (decreasing resistance caused by penetration (hole) in the suction strainer.
32686 (URGII wear), thus starving another critical The maximum width of deformable path . Or conversely, increased A settling velocity of0.2 ft/ s was particulates that may pass through the resistance from plu&1ing of a valve assigned for paint chips. Finally, a penetrations {holes) in passtve suction openin1, orifice, or heat exchaneer settlin& velocity of0.4 ft/s was assiened strainers is equal to the maximum linear tube may cause wear to occur in to concrete dust and other drywell dimension of the penetration {hole) in the another path that experiences partk:ulates. [ref NU REG CR 6224) suction strainer, plus 10 percent (10%). increased flow.
A settling velocity for NUCO N fibers The maximum thickness of deformable Sludge/ corrosion prod . 200 lbm used for preliminary assessment is 0 .25 particulates that may pass through the (density 324 lb/ft> per NEI 04-07 Table ft/sec based on having 1eometry of penetrations {holes) in a passive suct ion 4-21 partides that would bypass the suction strainers is equal to one-half (1/2) the lnorianic Zinc (102) 47 lbm st~iner. (ref boundinc NU REG CR 6224 maximum linear dimension of the {0.2516 ftl per URGJ Table 8-3 and NEI 04-07 Table 4-2]
penetration (hole) In the suction strainer.
Epoxy Coated 102 85 lbm The maximum cross-sectional area of 0 .65 ft>per URG) deformable particulates that may pass Rust Flakes 50 lbm (324 through the penetrations (holes) in a lb/ft> per NEI 04-07 Table 4-2]
passive suction strainers ts equal to the maximum cross-sectional flow area of the Oust / Dirt 150 lbm (156 penetration (hole) in the suction strainer, lb/ ft3 per NEI 04-07 Table 4-2) plus 10 percent (10%). Supp. Pool {SP) Initial Vol. (min.) "'
The maximum dimension {lencth, wtdth 3455 m3 (Ref oco T6.2-2) = 3.455 x and/or thickness) of non-deformable 106 liters.
particulates that may pass through a
((
suction strainer Is limited to the cross-sectional flow area of the penetration (hole) in the suction strainer. [ WCAP-0164061 GEH Public Page 95 of 105 1
NED0-33878 Revision 3 Non-Proprietary Information - Class I (Public)
Component r.omponent Mode of Operation System/ Component Flowrate Fluid Velocity thru Component System Descriptions and M ission Time Debris tn,fftton Model Wear Rate and Component Auxlllary Equlpment Evaluation ID EvaluaUon The materials involved are rl!lativl!ly stiff and incomprl!ssibll! and account for long, thin strands, of insulation being able to pass through tight openings.
It is assumed no settling of material once in solution. The material will tend to settle out in low flow areas in piping, the reactor Vl!ssel, the cont.illinment floor, or hold-up volumes.
It is .illssumed the dl!bris forms a homogeneous solution .lit the start of the event.
))
Experiml!ntal data on the effects of partiru1ates on pump hydraulic performancl! applied to ECCS type pumps show that pump performance degradation is negligible for partirutate concentrations less than 1% by votuml!. (Ref: NUREG/CR 2792)NUREG/CR 2792 notes conservative estimates of the nature and quantities of debris show th.lit fine abrasives may be present in concentrations of about 0 .1% by voluml! {about 400 ppm by weight).
and th.lit very conservative estimates of fibrous material yield concentrations of less th.illn 1% by volume. Published dat.ill on the effects of particul.illtes on pumps gl!nerally de.ill with particulate concentrations at m.illny times these values.
U71 Containment ((
DryweU Connecting Vents GEH Public Page 96 of 105 1
NED0-33878 Revision 3 Non-Proprietary Information - Class I (Public)
Component Component Mode of Operation System / Component Flowrate Fk.lld Veloctty thru Component System Descriptions and Mission Time Debris ln&estion Model Wear Rate and Component Au)(lliary Equipment Evaluation ID Evaluation
))
ESl*Ol RCIC System DCD S31.3.2.3 Wa ter Quality and Materials of construction for ECCS £valuation of Downstream Effects on
(( (( )) The Emergency Core Cooling (ECC)
Systems are designed to withstand a Submergence, provides reactor water system components are listed in DCD Major Components hostile environment and still perform quality cha racteristics for the design basis Table 6.1-1 Engineered Safety Features Both the HPCF and RCIC systems take
)) their function for 30 days following an LOCAs inside primary containment. Component Materials. primary suction from the CST and accident. Considering an ECCS mission time of secondary suction from the suppression
((
Note : RCIC is required to operate and 30 days (720 hrs.), (12 hrs credited for pool (SP) . The CST is clean is environmentally qualified for 12 hrs RCIC) the wear o f components demineratized water free of debris. This during OBA. subjected to the debris particles in assessment assumes most conservative solution (0.083 % SP volume) is alignment from the SP source.
(( considered insignificant. The effects of debris passing through (ref: An Assessment of Residual Heat the strainers on downstream Removal and Containment Spray Pump components such as pumps. valves. and Performance Under Air and Debris heat exchangers has been evaluated as Ingesting Conditions, NU REG/ CR- required under Reg Guide 1.82 Rev 4.
2792) This evaluation includes assessing wear on surfaces exposed to the fluid stream due to various types of debris: e.g.,
paint chips or RMI shards. £valuating
)) the potential for blockage of small clearances due to downstream debris are also included . The materials and cleara nces for the valves. pumps. and heat exchangers downstream of the ABWR ECCS suctio n strainers are essentially the same as the materials and clearances for the valves. pumps.
and he at exchangers downstream of the PWR containme,:it sump suction strainers. Therefore . Utilizing aspects applied to PWR methodology for the ABWR is appropriate . [ref STP DCD 6c.3.2]
The RCIC system has no tight clearance valves throttled during post LOCA operation that would be susceptible to blockage or binding. All RCIC valves in the post LOCA lineup will be closed (i.e .
isolate CST suction flow path) or fully open. As reflected on Table 1, Valve Position Chart, o n DCD Figure 5.4-9, Reactor Core Isolation Cooling System PFD (Sheet 2 of 2), no RCIC valves are throttled during this mode of operation .
RCIC minimum flo w is maintained by a piping orifice rather than throttling of the minimum flow valve. RCIC flow is varied by RCIC turbine speed by positioning th"e steam governor value to maintain system flow rather than throttling RCIC process valves. RCJC is required to support post LOCA function for12 hrs.
The RCIC system check valve installed in the main RCJC pump discharge line has GEH Public Page 97 of 105 1
NED0-33878 Revision 3 Non-Propr ietary Information - Class I (Public)
Component Component Mode of OperaUo n System / Component Flowrate Fluid Velod ty thn, Component System Descriptions and M ission Time Debris tnsestton Model WHr Rate *nd Compone nt AuxlUary Equlpment Evaluation 10 Eva lua Uon an activ@safety function to open. This RCIC valve is not susceptible to clogging,
))
settline or wear. The clearances of this check valve prevent debr is fro m adversely impacting the function of these components. The chedc valve material is carbon steel. Erosion or wear during the post LOCA credited 12 hr.
mission t ime will not impact SV5tem performance.
0002 Suction Strainer ([ ([ )) (( ([
))
))
))
X-214 Penetration ([ The ECCS piping / component flow area
([ (( ))
exceeds the maximum dimension of the debris particles. Therefore, clogging is not
)) considered credible .
))
GEH Public Page 98 of 105 1
NED0-33878 Revision 3 Non-Proprietary Information - Class I (Public)
Component Component Mode of Operation System/ Component Flowrate Fluid Velocity thru Component System OescripUons and Mtssk,n Time Debris ln1estion Model Wear Rate *nd Component Auxiliary Equipment Evaluation ID Evaluation f006 Motor Operated (( (( )) (( (( The ECCS piping / component flow area Block Valve eKceeds the maximum dimension of the debris particles. Therefore, dogging is not
)) )) considered credible.
))
f007 Check Valve (( (( )) (( The ECCS piping / component flow area exceeds the maximum dimension of the debris particles. Therefore, clogging is not
)) considered credible .
))
(001 RCIC Pump The ECCS piping / component flow area As described in NUREG /CR 2792, An NE00-32686 (URG) Vol 4 Evaluation of
(( (( )) (( ((
exceeds the maximum dimension of the Assessment of Residual Heat Removal the Effects of Debris on ECCS debris particles. Therefore, clogging is not and Containment Spray Performance Performance (GE-NE-T23-00700- 1S-21},
)) considered credible. Under Air and Debris Ingesting addresses safety and operational Conditions, concludes that under LOCA concerns for failure of ECCS pumps conditions with generated debris at associated with particles that pass the pump, pump performance through the ECCS suction strainers.
degradation is expected to be
-- negligible. In the event of shaft seal The ECCS pump design is coordinated with the ECC5 suction strainer si zing to failure due to wear or loss of cooling prevent clogging of pump internal fluid, seal safety bushings limit leakage passag@s including mechanical seal rates. This is based on a debris ass@mbti@s. The consequence of a
)) concentration less than 0.5% by plugged pump seal line would be high volume . seal temperature and poor seal life.
W hen considering long-term pump operation and performance, it is The ECCS pump includes a mechanical
)) necessary to consider how wear of seal assembly with cyclone particle interna l pump components will affect separator. A cyclone separator type of the pump hydraulic performance (total dynamic head and flow), the filtration is provided to maintain a clean cooling water supply to the seal.
mechanical performance (vibration ),
and pressure boundary integrity (shaft seals). The wear of the close running The size of orifices used to control the clearances may affect the hydraulic flow to ECCS pump seals is spedfi@d by performance because of increased the pump manufacturer to ensure the internal or bypass leakage. Multistage pump seal cooling lines are not pumps, designed for high head service, susceptible to plugging by debris not usually operate at speeds above the filtered by the cyclone sepa rator type first natural frequency of the rotating GEH Public Page 99 of 105 1
NED0-33878 Revision 3 Non-Proprietary Information - Class I (Public)
Component Component Mode of OpetaUon System/ Component Flowrate Fluid Velocity thru Component Syste m Descriptions a nd Mission Time Debris lncestlon Model Wear Rate and Component AuxlllaryEqulpment Evaluation ID Eva luation assembly. The running clearances of filter or debris larger than seal cooling the suction side and discharge side of line orifice hole diameter.
each impeller stage are designed and Wear rings and bushings are specifically manufactured to provide hydrostatic designed (hard materials) to resist wear support and damping for the rotating due to hard particulates in the process assembly, thus allowing operation at fluid. If the concentration of hard super-critical speeds without dynam ic particulates is unusually excessive, the insta bility. Increasing the dose running effect could bl! a long-term clearances due to wear may redu ce dl!teriotation in the pump performance, the overall shaft suppo rt stiffness at in the form of low pump head. The each impeller location, thus affecting requirement of 30 days of post LOCA the dy namic stability of the pump. operation is not considered long-term .
Debris in the pumped fluid may affect the sealing capability of mechanical shaft seals . These seals are dependent Seal Faces on seal injection flow to cool the New seal faces are lapped to very flat primary seal components. Debris in and smooth surfaces. Thi! working gap the pumped flow has the po tential of between the faces is a fraction of a blocking the seal injection flow path or micron . This means that large of limiting the performance of the seal particulates would pass over the seal components due to debris buildup in faces, and would not enter the interface bellows and springs. These effects mav to destroy thi! smoothness of the face lead to primary seal failure . Graphite and cause leakage.
safety bush ings (disaster bushings) may fail if exposed to high pressure fluid with debris follo wing a primary For the passive strainer with the holes seal failure thus providing an outside sized at 0 .125 in., little fiber is expected containment path for post-LOCA fluid. to pass throu~h after th!! initial filtM bed is formed, and also little of the
(( othM debris (e11cept for minimum sized iron oxide sludge ) is e11pected to pass after the initial fi lter bed precoat is formed . Therefor!!, all matMials would
)) most liketv pass through the orifice if 1% by volume of fibe r does not cause a Based on APl-610, a wear limit of 2X highly unlikely "btitz" which plugs t he as-new values is generally applied for orifice. Because all particles are larger pumps not analyzed (2X limit) . It is than a fraction of a micron, thev would i!Xpected that ECCS pumps operated not enter the pump seal fa ce. For for 30 days (720 hrs.) under modes of sh afts and bushings, debris in quantities operation assl!ssed and pumping liquid of one percl!nt o r less of the pump fluid at maximum suspended solids will not is likely to not constitute a major threat wear to a point where vibration will to the bushing integrity.
affect operability.
((
GEH Page 100 of 105 1 Public
NED0-33878 Revision 3 Non-Proprietary Information - Class I (Public)
Component Component Mode of Operation System / Component Fk>wrate Flukt Vek>clty thru Component System Oncriptk>>ns and Mfsslon Ttme C>eblis ln,estlon Model Wear Rate and Component Au,clllary Equipment Evaluation ID Evaluation
))
ECCS pump performance for the specific plant as-built configuration will require demo nstration of acceptable performance under design cond itions induding design debris loading.
Demonstration of acceptable performance for as-built ECCS pumps is validated undMQME-12007, Qualification of Active Mechanical Equipment Used in Nuclear Power GEH Page 101 of 105 1 Public
NED0-33878 Revision 3 Non-Proprietary Information - Class I (Public)
Component Component Mode of Operation System/ Component FJowrete Fk.l ld Vebclty thN Component System Descriptions a nd Mfss5on Time Deb ris lnt:fltion Model Wear Rate and Component Au,clllary Equipment Evaluat ion ID E\laluaUon Plants as endorsed by RG 1.100, "Seismic Qualification of Electrical and Active Mechanical Equipment and Functional Qualifica tio n of Active Mechanical Eq uipmen t for Nudear Power Plants," Revisio n 3, September 2009.
FE-007 Flow Element The ECCS pipinc / component flow uea
(( (( )) ((
l!Xceeds the mnimum dimension of the debris partides. Therefore, clouin& is not
)) considered credible.
))
F003 ChKkVatve The ECCS piping/ component now area
(( (( )) ((
exce~s the maximum dimension of the dtbris partides. Therefore, donin& is not
)) consider@d credible.
))
FDD4 Motor Operated (( (( The ECCS piping/ component flow area
(( )) ((
Block\/alve exce~s the maximum d imenston of the
)) debris partides. Therefore, clogging is not
)) considered credible.
))
GEH Public Page 102 of 1051
NED0-33878 Revision 3 Non-Proprietary Information - Class I (Public)
Component Component Mode of OperaUon System/ Component FJowrate Fh.dd Velocity thn, Component System OescripUons and Mittion Time Debris lnt:estlon Model Wear Rate and Component AuxlllaryEquipment Evaluation ID Evaluation Check Valve (Air (( The ECCS piping/ component flow area N22 (( (( ))
Feedwater Testable) exceeds the maximum dimension of the System debris partides. Therefore, cloning is not FOOS )) considered credible.
))
The ECCS piping/ component flow area N22 Check Valve !Air (( (( )) ((
Feedwater Testable) exceeds the maximum dimension of the System debris particles. Therefore, clogging is not F003 )) considered credible.
))
N22 Penetr;ition
(( (( )) (( The ECCS piping / component flow aru Feedwater exceeds the maximum dimension of the System debris particles. Therefore, clogginc is not X-12B )) considered credible.
))
N22 Ched<Valve (( (( The ECCS piping / component flow area
(( ))
Feedwater exceeds the maximum dimension of the System debris partides. Therefore, clogging is not F004B )) considered credible.
))
GEH Page 103 of 105 1 Public
NED0-33878 Revision 3 Non-Pr oprietary Information - Class I (Public)
Component Component Mode of Operation Sv,t:em / Component Flowrate Fklld Vek>cltythru Component System Dffcriptk>ns and MKslon Tlme Debris ln,estlon Model Wear Rate *nd Component Au,clllary Equipment Evaluatio n ID EvaluaUon N22 The ECCS pipin& / component flow are.i Manual Block (( (( )) ((
Feedwilter Valve exceeds the maximum dimension of the System debris partides. Therefore, cloggin& is not FOOSB )) considered credible.
))
Reactor Feedwater (( )) (( (( ((
(( ((
Intern als Spar1ers (Reactor Pressure )) )) ))
Vessel 811] The diameter of the feedwatu sparau nozzle eKceeds the maximum dimenston (lengt h, width and/ or thickne ss) of non*
deformable particulates that may pass through the st rainer. Therefore, fouling of
)) this component due to debris downstream the ECC5 suction strainer is not credible.
))
Ructor Reactor Assembty (( (( )) (( The reactor vessel ffow area orifices Internals u:ceeds the maximum dimension of the
{Reactor debris partides. Therefore, clogcing tS not Pressure )) co nsidered credible.
Vessel 811]
))
JU Fuel (( (( )) ((
Assembly
))
GEH Page 104 of 105 1 Public -
NED0-33878 Revision 3 Non-Proprietary Information - Class I (Public}
Component Component Mode of Operation Svstem / Component Flowrate Fklkt Vek>clty thru Component System Dflcriptlons and Minion Time Debris lna:esUon Model Wear Rate and Component Auxlllary Equipment Evaluation 10 Evaluation
))
GEH Page 105 of 105 1 Public