US EPR Fuel Assembly Mechanical Design Topical Report.

133 Pages·2013·6.33 MB·English

A
AREVA
U.S. EPR Fuel Assembly ANP-10285NP
Revision 1
Mechanical Design
Topical Report
May 2013
AREVA NP Inc.
(c) 2013 AREVA NP Inc.
Copyright © 2013
AREVA NP Inc.
All Rights Reserved
AREVA NP Inc. ANP-10285NP
Revision 1
U.S. EPR Fuel Assembly Mechanical Design
Topical Report Pa-qe i
Nature of Changes
Section(s)
Item or Page(s) Description and Justification
1 All Initial Issue
2 3.3 Revised to reflect modifications to spacer grids
3.8 Revisions to fuel assembly and component testing
descriptions.
5.0 Revised to reflect the use of ANP-10325P.
5.1.1.3 Revised to reflect bottom nozzle evaluation.
5.1.1.5 Revised to reflect new spacer grid strength evaluations.
5.1.6 Figure 5-2 revised.
5.1.7 Revisions to account for revised fuel assembly growth
models.
5.1.9 Revised to reflect use of statistical holddown methodology.
5.3.4 Revised to reflect new fuel assembly structural damage
from external forces methodology.
5.4.1 Revised to reflect new hydraulic loss coefficients.
5.4.2 Revised to reflect the use of statistical holddown
methodology.
AREVA NP Inc. ANP-10285NP
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U.S. EPR Fuel Assembly Mechanical Design
Topical Report Page ii
Contents
Pa.. e
1.0 INTRODUCTION...................................................................... 1-1
2 .0 S UM M A R Y ........................................................................................................ 2-1
3.0 U.S. EPR FUEL DESIGN DESCRIPTION ......................................................... 3-1
3 .1 F uel A ssem bly ........................................................................................ 3-1
3 .2 F ue l R o d ................................................................................................. 3 -3
3 .3 S pace r G rids ........................................................................................... 3-5
3.4 Low Pressure Drop Top Nozzle .............................................................. 3-6
3.5 Debris Filter (FUELGUARDTM ) Bottom Nozzle ....................................... 3-7
3.6 M 5TM A lloy G uide Tube ........................................................................... 3-8
3 .7 Ma te ria ls ................................................................................................. 3-9
3.8 Fuel A ssem bly Testing .......................................................................... 3-30
3.8.1 S haker T ests .............................................................................. 3-31
3.8.2 Lateral Im pact Tests ................................................................... 3-31
3.8.3 Static Stiffness Tests .................................................................. 3-31
3.8.4 Fuel Assembly Drop Tests ......................................................... 3-32
3.8.5 Fuel Hydraulic Flow Tests .......................................................... 3-32
3.8.6 CRDM Driveline/RCCA Drop Testing ......................................... 3-33
3.9 Fuel Assembly Component Testing ...................................................... 3-34
3.9.1 Holddown Spring Characteristic Tests ....................................... 3-34
3.9.2 Strength Test of Upper Guide Tube Connection ........................ 3-36
3.9.3 Spacer G rid Testing ................................................................... 3-36
3.9.4 Strength Test of Bottom Nozzle ................................................. 3-36
4.0 RELEVANT OPERATING EXPERIENCE ......................................................... 4-1
4.1 Operational Experience with HTP Fuel Assemblies ................................ 4-2
4.2 Advanced HTP Fuel Assembly Designs ................................................. 4-7
4.2.1 HTP Fuel Assemblies Equipped with an HMP Spacer
at Low erm ost Position .................................................................. 4-8
4.2.2 HTP Spacers Made of M5TM Alloy ................................................ 4-9
4.2.3 HTP Fuel Assemblies Equipped with M5 TM Clad Rods ............. 4-10
4.2.4 Summary of Advanced HTP Fuel Assembly Designs ................ 4-11
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U.S. EPR Fuel Assembly Mechanical Design
Topical Report Pacie iii
4.3 O perational Experience w ith M5 Tm Alloy ............................................... 4-18
4.4 Operational Experience with 14 ft Fuel Assembly Designs ................... 4-21
4.5 O perational Behavior and Reliability ..................................................... 4-21
4.6 Post Irradiation Examination of U.S. EPR 14 foot Fuel
Assem bly .............................................................................................. 4-23
5.0 DESIG N EVALUATIO N ..................................................................................... 5-1
5.1 Fuel System Dam age Criteria ................................................................. 5-1
5.1.1 Stress ........................................................................................... 5-1
5.1.2 Cladding Strain ........................................................................... 5-20
5.1.3 Cladding Fatigue ........................................................................ 5-21
5.1.4 Fretting ....................................................................................... 5-22
5.1.5 Oxidation, Hydriding, and Crud Buildup ..................................... 5-26
5.1.6 Fuel Rod Bow ............................................................................. 5-27
5.1.7 Axial G rowth ............................................................................... 5-29
5.1.8 Fuel Rod Internal Pressure ........................................................ 5-34
5.1.9 Assem bly Liftoff .......................................................................... 5-35
5.2 Fuel Rod Failure Criteria ....................................................................... 5-39
5.2.1 Internal Hydriding ....................................................................... 5-39
5.2.2 Cladding Collapse ...................................................................... 5-39
5.2.3 Overheating of Cladding ............................................................ 5-41
5.2.4 Overheating of Fuel Pellets ........................................................ 5-42
5.2.5 Pellet/Cladding Interaction ......................................................... 5-42
5.2.6 Cladding Rupture ....................................................................... 5-42
5.3 Fuel Coolability ...................................................................................... 5-42
5.3.1 Cladding Em brittlem ent .............................................................. 5-42
5.3.2 Violent Expulsion of Fuel ............................................................ 5-43
5.3.3 Fuel Rod Ballooning ................................................................... 5-43
5.3.4 Fuel Assembly Structural Damage from External
Forces ........................................................................................ 5-43
5.3.5 Core Pressure Drop ................................................................... 5-44
5.3.6 Fuel Assem bly Hydraulic Lift ...................................................... 5-46
5.3.7 Core DN13 Analyses ................................................................... 5-47
5.3.8 Fuel Rod Perform ance ............................................................... 5-47
5.4 Design Evaluation Sum m ary ................................................................. 5-51
6.0 DESIG N CHANG E PRO CESS ........................................................................ 6-54
6.1 Criteria to be Used When Making Design Changes .............................. 6-54
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U.S. EPR Fuel Assembly Mechanical Design
Tnnio.si Renort Pane iv
6.2 Types of Design Changes ..................................................................... 6-55
6.3 Summary .............................................................................................. 6-56
7.0 REFERENCES .................................................................................................. 7-1
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U.S. EPR Fuel Assembly Mechanical Design
Topical Report Page v
List of Tables
Table 3-1 Comparison of U.S. EPR to Advanced Mark-BW and 12-Foot HTP 17
Fuel Assem bly Param eters ....................................................................... 3-10
Table 3-2 Comparison of U.S. EPR and Advanced Mark-BW Fuel Rod
P a ra m ete rs ............................................................................................... 3-1 1
Table 3-3 Comparison of U.S. EPR, Advanced Mark-BW, and 17x17 HTP Grid
P a ra m ete rs ............................................................................................... 3 -12
Table 3-4 Comparison of U.S. EPR and Advanced Mark-BW Guide Tube and
Instrum ent Sheath Param eters ................................................................. 3-13
Table 3-5 Summary of Component Materials ........................................................... 3-14
Table 3-6 Fuel Rod Param eters ................................................................................ 3-14
Table 3-7 Fuel Rod Cladding Parameters ................................................................. 3-15
Table 3-8 U 0 2 Pellet Param eters ............................................................................... 3-15
Table 3-9 Gadolinium Pellet Parameters ................................................................... 3-16
Table 3-10 Fuel Rod Spring Dimensions ................................................................... 3-17
Table 3-11 Fuel Rod Support Tube Dimensions ....................................................... 3-17
Table 3-12 Fuel Rod End Plug Dimensions .............................................................. 3-17
Table 4-1 Operational Experience with HTP Fuel Assembly (Status as of
D ecem ber 2006) ......................................................................................... 4-5
Table 4-2 Operating Experience in 17x17 HTP Fuel Assemblies for (12 ft)
Framatome and W-Plants (Status as of December 2006) ........................ 4-12
Table 4-3 Operating Experience in 15x15 HTP Fuel Assemblies for (12 ft) W-
Plants (Status as of December 2006) ....................................................... 4-13
Table 4-4 Operating Experience in 14x14 HTP Fuel Assemblies in W-Plants
(Status as of Decem ber 2006) .................................................................. 4-14
Table 4-5 Operating Experience in 15x15 HTP Fuel Assemblies for CE Plants
(Status as of Decem ber 2006) .................................................................. 4-15
Table 4-6 Operating Experience in 14x14 HTP Fuel Assemblies for CE Plants
(Status as of Decem ber 2006) .................................................................. 4-16
Table 4-7 Operating Experience in 15x15 HTP Fuel Assemblies for B&W Plants
(Status as of Decem ber 2006) .................................................................. 4-17
AREVA NP Inc. ANP-10285NP
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U.S. EPR Fuel Assembly Mechanical Design
Topical Report Page vi
Table 4-8 Global M5TM Fuel Rod Operational Experience (as of January 2007) ...... 4-19
Table 4-9 Global M5TM Structure Operational Experience (as of January 2007) ....... 4-20
Table 4-10 HTP Fuel Assembly Rod Failures and Causes (Status as of
D ecem ber 2006) ....................................................................................... 4-22
Table 5-1 Guide Tube Stress Margins for Normal Operation ...................................... 5-5
Table 5-2 Top Nozzle Summary of Margins of Safety for Normal Operation .............. 5-7
Table 5-3 Top Nozzle Summary of Margins of Safety for Faulted Conditions ............ 5-8
Table 5-4 Top Nozzle Summary of Margins of Safety for Shipping and Handling ...... 5-8
Table 5-5 Guide Tube Screw and End Plug Preload Stress, psi .............................. 5-10
Table 5-6 Guide Tube Screw and End Plug Preload Stress+Handling, psi .............. 5-10
Table 5-7 Connections Normal Operating Stress Evaluation .................................... 5-11
Table 5-8 G rouped Transients .................................................................................. 5-15
Table 5-9 Holddown Spring Derived Fatigue Usage Factors, Ui ............................... 5-17
Table 5-10 Classifications of Fuel Rod Clad Stresses ............................................... 5-19
Table 5-11 U.S. EPR Fuel Rod Stress Result Summary ........................................... 5-20
Table 5-12 System State Point Parameters for Assembly Liftoff Evaluation ............ 5-36
Table 5-13 Summary of 95/95 Minimum Holddown Forces ....................................... 5-38
Table 5-14 Summary of RCS Design Transients (Sheet 1 of 2) ................................. 5-52
Table 5-14 Summary of RCS Design Transients (Sheet 2 of 2) ............................... 5-53
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U.S. EPR Fuel Assembly Mechanical Design
Topical Report Paae vii
List of Figures
Figure 3-1 U.S. EPR Fuel Assem bly ........................................................................ 3-18
Figure 3-2 Instrum ent Lance Position ........................................................................ 3-19
Figure 3-3 Fuel R od A ssem bly .................................................................................. 3-20
Figure 3-4 FUELGUARDTM Bottom Nozzle Arrangement (Dimensions in
m illim ete rs) ............................................................................................... 3-2 1
Figure 3-5 FUELGUARDTM Bottom Nozzle ............................................................... 3-22
Figure 3-6 Intermediate-HTP Spacer Grid Assembly (Dimensions in millimeters) ... 3-23
Figure 3-7 HTP Spacer Grid Characteristics ............................................................. 3-24
Figure 3-8 HMP End Grid Assembly (Dimensions in millimeters) ............................ 3-25
Figure 3-9 Guide Tube Assembly (Dimensions in millimeters) ................................. 3-26
Figure 3-10 QD Top Nozzle Assembly ...................................................................... 3-27
Figure 3-11 QD Top Nozzle Assembly (Dimensions in millimeters) ........................ 3-28
Figure 3-12 QD Connection at Top Nozzle ............................................................... 3-29
Figure 3-13 Guide Tube Connection at Bottom Nozzle ............................................. 3-29
Figure 3-14 U.S. EPR Holddown Spring Single Set Force/Deflection Curve ............ 3-35
Figure 4-1 Burnup Distribution of the HTP Fuel Assembly (Status as of
D ecem ber 2006) ......................................................................................... 4-6
Figure 4-2 Burnup Distribution of HTP Fuel Assembly featuring an HMP at
Lowermost Position (Status as of December 2006) .................................... 4-8
Figure 4-3 Burnup Distribution of HTP Fuel Assemblies Featuring a Zirconium
Alloy HTP Spacer at the Uppermost Position (Status as of December
2 0 0 6 ) ......................................................................................................... 4 -10
Figure 4-4 Burnup Distribution of HTP Fuel Assemblies with Fuel Rods
Fabricated with M5TM Cladding Material (Status as of December
2 0 0 6 ) ......................................................................................................... 4- 1 1
Figure 4-5 International Distribution of Fuel Assemblies containing M5 TM Fuel
Rods (Status as of December 2006) ......................................................... 4-18
Figure 5-1 Transients Strains over 3 cycles of Heat-Up and Cool-Down .................. 5-16
Figure 5-2 Worst Case Water Channel Closure versus Burnup ................................ 5-28
AREVA NP Inc. ANP-10285NP
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U.S. EPR Fuel Assembly Mechanical Design
Tonical Renort Paae viii
Figure 5-3 U.S. EPR Fuel Assembly Growth Limits .................................................. 5-33
Figure 5-4 U.S. EPR Fuel Rod Growth Limits ........................................................... 5-34
Figure 5-5 Average Heating Rate - U0 , 18-month Equilibrium ................................ 5-48
2
Figure 5-6 Fuel Average Temperature - U0 , 18-month Equilibrium ......................... 5-49
2
Figure 5-7 Rod Internal Pressures (RIP) - U0 , 18-month Equilibrium .................... 5-50
2
Figure 5-8 U.S. EPR Limiting Clad Strain (CS) & Centerline Fuel Melt (CFM)
C u rve s ...................................................................................................... 5 -5 1