ML103260322

ANP-2948NP, Rev. 0, Mechanical Design Report for Brunswick Atrium 10XM Fuel Assemblies, Enclosure 3 to BSEP 10-0126

ML103260322
Person / Time
Site:	Brunswick
Issue date:	10/31/2010
From:	AREVA NP
To:	Office of Nuclear Reactor Regulation
References
BSEP 10-0126, TAC ME3856, TAC ME3857, TAC ME3858, TAC ME3859, TSC-2010-01, TSC-2010-02 ANP-2948NP, Rev 0
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{{#Wiki_filter:BSEP 10-0126 Enclosure 3 AREVA Report ANP-2948NP, Revision 0, Mechanical Design Report for Brunswick ATRIUM 1 OXM Fuel Assemblies, dated October 2010 Controlled Document ANP-2948NP Revision 0 Mechanical Design Report for Brunswick ATRIUM 1OXM Fuel Assemblies October 2010 AR EVA AREVA NP Incý. Controlled Document AREVA NP ANP-2948NP Revision 0 Mechanical Design Report for Brunswick ATRIUM 1OXM Fuel Assemblies Controlled Document AREVA NP AREVA NP Inc.ANP-2948NP Revision 0 Copyright © 2010 AREVA NP Inc.All Rights Reserved Controlled Document AREVA NP Mechanical Design Report for Brunswick ATRIUM 1OXM Fuel Assemblies ANP-2948NP Revision 0 Paae i Nature of Changes Revision Section(s) Item Number or Page(s) Description and Justification

1. 0 All This is the initial release.AREVA NP Inc.

Controlled Document AREVA NP ANP-2948NP Mechanical Design Report for Revision 0 Brunswick ATRIUM 1OXM Fuel Assemblies Page ii Contents 1 .0 In tro d u ctio n ..................................................................................................................... 1 2.0 Design Description .................................................................................................... 2 2.1 Overview ......................................................................................................... 2 2.2 Fuel Assem bly ................................................................................................ 2 2.2.1 Spacer Grid ..................................................................................... .3 2.2.2 W ater Channel .................................................................................. 3 2.2.3 Lower Tie Plate .................................................................................. 4 2.2.4 Upper Tie Plate and Connecting Hardware ................... 4 2.2.5 Fuel Rods ......................................................................................... 5 2.3 Fuel Channel and Com ponents ...................................................................... 6 3.0 Fuel Design Evaluation .............................................................................................. 9 3.1 Objectives ....................................................................................................... 9 3.2 Fuel Rod Evaluation ...................................................................................... 9 3.3 Fuel System Evaluation .................................................................................. 9 3.3.1 Stress, Strain, or Loading Limits on Assembly Components ............ 10 3.3.2 Fatigue ............................................................................................ 10 3.3.3 Fretting W ear .................................................................................. 11 3.3.4 Oxidation, Hydriding, and Crud Buildup ........................................... 11 3.3.5 Rod Bow ......................................................................................... 11 3.3.6 Axial Irradiation Growth ..................................................................... 12 3.3.7 Rod Internal Pressure ..................................................................... 12 3.3.8 Assem bly Lift-off .............................................................................. 12 3.3.9 Fuel Assem bly Handling .................................................................. 13 3.3.10 Miscellaneous Com ponent Criteria ................................................. 14 3.3.10.1 Compression Spring Forces ............................................ 14 3.3.10.2 LTP Seal Spring ............................................................. 14 3.4 Fuel Coolability .............................................................................................. 14 3.4.1 Cladding Em brittlement ................................................................... 14 3.4.2 Violent Expulsion of Fuel ................................................................. 15 3.4.3 Fuel Ballooning ................................................................................ 15 3.4.4 Structural Deform ations .................................................................. 15 3.4.4.1 Fuel Storage Seismic Qualification .................................. 16 3.5 Fuel Channel and Fastener ........................................................................... 16 3.5.1 Design Criteria for Normal Operation ............................................... 16 3.5.2 Design Criteria for Accident Conditions ........................................... 17 4.0 Mechanical Testing .................................................................................................. 24 4.1 Fuel Assem bly Axial Load Test ..................................................................... 24 4.2 Spacer Grid Lateral Im pact Strength Test .................................................... 24 4.3 Tie Plate Strength Tests ................................................................................ 25 4.4 Debris Filter Efficiency Test ........................................................................... 25 4.5 Fuel Assem bly Fretting Test ......................................................................... 26 4.6 Fuel Assem bly Static Lateral Deflection Test ................................................ 26 4.7 Fuel Assem bly Lateral Vibration Tests ......................................................... 26 AREVA NP Inc. Controlled Document AREVA NP ANP-2948NP Mechanical Design Report for Revision 0 Brunswick ATRIUM 1OXM Fuel Assemblies Page iii 4.8 Fuel Assembly Impact Tests ......................................................................... 27 5 .0 R efe re n ce s .................................................................................................................... 2 8 A ppendix A Illustrations .................................................................................................. 29 AREVA NP Inc. Controlled Document AREVA NP ANP-2948NP Mechanical Design Report for Revision 0 Brunswick ATRIUM 1OXM Fuel Assemblies Page iv Tables Table 2-1 Fuel Assembly and Component Description ......................................................... 7 Table 2-2 Fuel Channel and Fastener Description ................................................................ 8 Table 3-1 Results for ATRIUM 1OXM Fuel Assembly ........................................................... 18 Table 3-2 Results for Advanced Fuel Channels .................................................................. 21 Table 3-3 Results for Channel Fasteners ........................................................................... 23 Figures Figure A-1 ATRIUM 1OXM Fuel Assembly .......................................................................... 30 Figure A-2 UTP with Locking Hardware ............................................................................. 31 Figure A-3 Improved FUELGUARD LTP ............................................................................. 32 Figure A-4 ATRIUM 1OXM ULTRAFLOW Spacer Grid ......................................................... 33 Figure A-5 Full and Part-Length Fuel Rods ......................................................................... 34 Figure A-6 Advanced Fuel Channel .................................................................................... 35 Figure A-7 Fuel Channel Fastener Assembly ....................................................................... 36 This document contains a total of 44 pages.AREVA NP Inc. Controlled Document AREVA NP ANP-2948NP Mechanical Design Report for Revision 0 Brunswick ATRIUM 1OXM Fuel Assemblies Page v Nomenclature Acronym Definition AFC Advanced fuel channel AOO Anticipated operational occurrences ASME American Society of Mechanical Engineers B&PV Boiler and pressure vessel BWR Boiling water reactor CHF Critical heat flux EOL End of life FPM Fuel preparation machine HDSFSR High density spent fuel storage racks LOCA Loss-of-coolant accident LTP Lower tie plate MWd/kgU Megawatt-days per kilogram of Uranium NFS New fuel storage NRC U. S. Nuclear Regulatory Commission PLFR Part-length fuel rods psi Pounds per square inch RPV Reactor pressure vessel Sn Design stress intensity SRA Stress relief annealed SRP Standard review plan Su Ultimate stress SY Yield stress AREVA NP Inc. Controlled Document AREVA NP ANP-2948NP Mechanical Design Report for Revision 0 Brunswick ATRIUM 1 OXM Fuel Assemblies Page 1 1.0 Introduction This report provides a design description, mechanical design criteria, fuel structural analysis results, and test results for the ATRIUM T M* 10 XM fuel assembly and 100/75 Advanced Fuel Channel (AFC) designs supplied by AREVA NP Inc. (AREVA) for use at Brunswick Nuclear Plant beginning with Unit 2 Cycle 20 and Unit 1 Cycle 19.The scope of this report is limited to an evaluation of the structural design of the fuel assembly and channel. The fuel assembly structural design evaluation is not cycle-specific so this report is intended to be referenced for each cycle where the fuel design is in use. Minor changes to the fuel design and cycle-specific input parameters will be dispositioned for future reloads. AREVA will confirm the continued applicability of this report prior to delivery of each subsequent reload of ATRIUM 1 OXM fuel at Brunswick Units I and 2.The fuel assembly design was evaluated according to the AREVA boiling water reactor (BWR) generic mechanical design criteria (Reference 1). The fuel channel design was evaluated to the criteria given in fuel channel topical report (Reference 2). The generic design criteria have been approved by the U.S.Nuclear Regulatory Commission (NRC) and the criteria are applicable to the subject fuel assembly and channel design.Mechanical analyses have been performed using NRC-approved design analysis methodology (References 1, 2, 3, and 4). The methodology permits maximum licensed assembly and fuel channel exposures of 54 MWd/kgU (Reference 3). Documentation of compliance with the generic design criteria using approved methods demonstrates licensing approval of the fuel design.The fuel assembly and channel meets all mechanical compatibility requirements for use in Brunswick Units 1 and 2. This includes compatibility with both co-resident fuel and the reactor core internals. ATRIUM is a trademark of AREVA NP Inc.AREVA NP Inc. Controlled Document AREVA NP Mechanical Design Report for Brunswick ATRIUM 1OXM Fuel Assemblies ANP-2948NP Revision 0 Page 2 2.0 Design Description This report documents the structural evaluation of the ATRIUM 1OXM fuel assembly and fuel channel described below. Reload-specific design information is available in the design package provided by AREVA for each reload delivery.2.1 Overview Brunswick has successfully operated for several cycles with the ATRIUM-10 fuel design. In general, the design changes introduced with the ATRIUM 1OXM are evolutionary in nature and represent a []. The ATRIUM 1OXM fuel bundle shares the same basic geometry as the ATRIUM-10 fuel assembly design.This geometry consists of a 10x10 fuel lattice with a square internal water channel that displaces a 3x3 array of rods. Relative to the ATRIUM-b0 fuel, the ATRIUM 1OXM incorporates the following key design features:]Table 2-1 lists the key design parameters of the ATRIUM 1OXM fuel assembly.2.2 Fuel Assembly The ATRIUM 1OXM fuel assembly consists of a lower tie plate (LTP) and upper tie plate (UTP), 91 fuel rods, nine spacer grids, a central water channel with [ ], and miscellaneous assembly hardware. Of the 91 fuel rods, twelve are PLFRs. The structural members of the fuel AREVA NP Inc. Controlled Document AREVA NP Mechanical Design Report for Brunswick ATRIUM 1OXM Fuel Assemblies ANP-2948NP Revision 0 Page 3 assembly include the tie plates, spacer grids, water channel, and connecting hardware. The structural connection between the LTP and UTP is provided by the central water channel. The lowest of the nine spacer grids is located just above the LTP to restrain the lower ends of the fuel rods.The fuel assembly is accompanied by a fuel channel, as described later in this section.Table 2-1 lists the main fuel assembly attributes, and an illustration of the fuel bundle assembly is provided in the appendix.2.2.1 Spacer Grid Table 2-1 lists the main spacer grid attributes, and an illustration of the spacer grid is provided in the appendix.2.2.2 Water Channel[t ULTRAFLOW is a trademark of AREVA NP Inc.AREVA NP Inc. Controlled Document AREVA NP Mechanical Design Report for Brunswick ATRIUM 1OXM Fuel Assemblies ANP-2948NP Revision 0 Page 4 Table 2-1 lists the main water channel attributes and the appendix provides an illustration of a section of the water channel.2.2.3 Lower Tie Plate The appendix provides an illustration of the LTP.2.2.4 Upper Tie Plate and Connectingq Hardware I FUELGUARD is a trademark of AREVA NP Inc.AREVA NP Inc. Controlled Document AREVA NP Mechanical Design Report for Brunswick ATRIUM 1OXM Fuel Assemblies ANP-2948NP Revision 0 Page 5 The appendix provides an illustration of the UTP and locking components. 2.2.5 Fuel Rods[AREVA NP Inc. Controlled Document AREVA NP Mechanical Design Report for Brunswick ATRIUM 1 OXM Fuel Assemblies ANP-2948NP Revision 0 Page 6.Table 2-1 lists the main fuel rod attributes, and the appendix provides an illustration of the full length and part length fuel rods.2.3 Fuel Channel and Components [Table 2-2 lists the fuel channel component attributes. The fuel channel and fuel channel fastener are depicted in the appendix.AREVA NP Inc. Controlled Document AREVA NP Mechanical Design Report for Brunswick ATRIUM 1OXM Fuel Assemblies ANP-2948NP Revision 0 Page 7 Table 2-1 Fuel Assembly and Component Description [i I AREVA NP Inc. Control DJ cumnent Mechanical Design Report for Brunswick ATRIUM 1 OXM Fuel Assemblies ANP-2948NP Revision 0 Page 8 Table 2-2 Fuel Channel and Fastener Description i i I AREVA NP Inc. ControW.[J r9cument ANP-2948NP Mechanical Design Report for Revision 0 Brunswick ATRIUM I OXM Fuel Assemblies Page 9 3.0 Fuel Design Evaluation A summary of the mechanical methodology and results from the structural design evaluations is provided in this section. Results from the mechanical design evaluation demonstrate that the design satisfies the mechanical criteria to the analyzed exposure limit.3.1 Objectives The objectives of designing fuel assemblies (systems) to specific criteria are to provide assurance that:* The fuel assembly (system) shall not fail as a result of normal operation and anticipated operational occurrences (AOOs). The fuel assembly (system) dimensions shall be designed to remain within operational tolerances, and the functional capabilities of the fuels shall be established to either meet or exceed those assumed in the safety analysis.* Fuel assembly (system) damage shall never prevent control rod insertion when it is required.* The number of fuel rod failures shall be conservatively estimated for postulated accidents." Fuel coolability shall always be maintained.

• The mechanical design of fuel assemblies shall be compatible with co-resident fuel and the reactor core internals.
• Fuel assemblies shall be designed to withstand the loads from handling and shipping.The first four objectives are those cited in the Standard Review Plan (SRP). The latter two objectives are to assure the structural integrity of the fuel and the compatibility with the existing reload fuel. To satisfy these objectives, the criteria are applied to the fuel rod and the fuel assembly (system) designs. Specific component criteria are also necessary to assure compliance.

The criteria established to meet these objectives include those given in Chapter 4.2 of the SRP.3.2 Fuel Rod Evaluation The mechanical design report documents the fuel structural analyses only and does not include the fuel rod evaluation. 3.3 Fuel System Evaluation The detailed fuel system design evaluation is performed to ensure the structural integrity of the design under normal operation, AOO, faulted conditions, handling operations, and shipping. The analysis methods are based on fundamental mechanical engineering techniques-often employing finite element analysis, prototype testing, and correlations based on in-reactor performance data. Summaries of the major assessment topics are described in the sections that follow.AREVA NP Inc. Controlled Document AREVA NP ANP-2948NP Mechanical Design Report for Revision 0 Brunswick ATRIUM 10XM Fuel Assemblies Page 10 3.3.1 Stress, Strain, or Loadingq Limits on Assembly Components The structural integrity of the fuel assemblies is assured by setting design limits on stresses and deformations due to various handling, operational, and accident or faulted loads. AREVA uses Section III of the ASME B&PV Code as a guide to establish acceptable stress, deformation, and load limits for standard assembly components. These limits are applied to the design and evaluation of the UTP, LTP, spacer grids, springs, and load chain components, as applicable. The fuel assembly structural component criteria under faulted conditions are based on Appendix F of the ASME B&PV Code Section III with some criteria derived from component tests.All significant loads experienced during normal operation, AQOs, and under faulted conditions are evaluated to confirm the structural integrity of the fuel assembly components. Outside of faulted conditions, most structural components are under the most limiting loading conditions during fuel handling. See Section 3.3.9 for a discussion of fuel handling loads and Section 3.4.4 for the structural evaluation of faulted conditions. Although normal operation and AOO loads are often not limiting for structural components, a stress evaluation may be performed to confirm the design margin and to establish a baseline for adding accident loads. The stress calculations use conventional, open-literature equations. A general-purpose, finite element stress analysis code, such as ANSYS, may be used to calculate component stresses.See Table 3-1 for results from the component strength evaluations.

3.3.2 Fatigue

Fatigue of structural components is generally []1.AREVA NP Inc. Controlled Document AREVA NP Mechanical Design Report for Brunswick ATRIUM 1OXM Fuel Assemblies ANP-2948NP Revision 0 Page 11 3,3.3 Frettinq Wear Fuel rod failures due to grid-to-rod fretting shall not occur. [.Fretting wear is evaluated by testing, as described in Section 4.5. The testing is conducted by []. The inspection measurements for wear are documented. The lack of significant wear demonstrates adequate rod restraint geometry at the contact locations. Also, the lack of significant wear at the spacer cell locations relaxed to EOL conditions provides further assurance that no significant fretting will occur at higher exposure levels.[3 and has operated successfully without incidence of grid-to-rod fretting in more than 20,000 fuel assemblies. 3.3.4 Oxidation, Hvdridinci, and Crud Buildup Because of the low amount of corrosion on fuel assembly structural components, [3.3.5 Rod Bow Differential expansion between the fuel rods and cage structure, and lateral thermal and flux gradients can lead to lateral creep bow of the rods in the spans between spacer grids. This lateral creep bow alters the pitch between the rods and may affect the peaking and local heat transfer. The AREVA design criterion for fuel rod bowing is that [Rod bow is calculated using the approved model described in Reference

4. The model has been shown to be conservative for application to the ATRIUM-10 fuel design. Less rod bow is predicted for the ATRIUM 10XM compared to the ATRIUM-10 due to a larger diameter fuel rod and a reduced distance AREVA NP Inc.

Contaro" -k Dcument AREVA NP ANP-2948NP Mechanical Design Report for Revision 0 Brunswick ATRIUM 1OXM Fuel Assemblies Page 12 between most spacer grids. []. The predicted rod-to-rod gap closure due to bow is assessed for impact on thermal margins.3.3.6 Axial Irradiation Growth Fuel assembly components, including the fuel channel, shall maintain clearances and engagements, as appropriate, throughout the design life. Three specific growth calculations are considered for the ATRIUM 1OXM design: " minimum fuel rod clearance between the LTP and UTP* minimum engagement of the fuel channel with the LTP seal spring" external interfaces (e.g., channel fastener springs)Rod growth, assembly growth, and fuel channel growth are calculated using correlations derived from post-irradiation data. The evaluation of initial engagements and clearances accounts for the combination of fabrication tolerances on individual component dimensions. The SRA fuel rod growth correlation was established from []. Assembly growth is dictated by the water channel growth. The growth of the water channel and the fuel channel is based on [ ]. These data and the resulting growth correlations are described in Reference

3. The upper and lower [], as appropriate, are used to obtain EOL growth values.The minimum EOL rod growth clearance and EOL fuel channel engagement with the seal spring are listed in Table 3-1. The channel fastener spring axial compatibility is reported in Table 3-3.3.3.7 Rod Internal Pressure The fuel rod thermal-mechanical evaluation is not part of the structural analysis.3.3.8 Assembly Lift-off Fuel assembly lift-off is evaluated under both normal operating conditions (including AQOs) and under faulted conditions.

The fuel shall not levitate under normal operating or AOO conditions. Under postulated accident conditions, the fuel shall not become disengaged from the fuel support. These AREVA NP Inc. Controiled Document AREVA NP ANP-2948NP Mechanical Design Report for Revision 0 Brunswick ATRIUM 1OXM Fuel Assemblies Page 13 criteria assure control blade insertion is not impaired. Additionally, Brunswick meets a more stringent requirement of no liftoff under applicable plant licensing basis accident conditions. For normal operating conditions, the net axial force acting on the fuel assembly is calculated by adding the loads from gravity, hydraulic resistance from coolant flow, difference in fluid flow entrance and exit momentum, and buoyancy. The calculated net force is confirmed to be in the downward direction, indicating no assembly lift-off. Maximum hot channel conditions are used in the calculation because the greater two-phase flow losses produce a higher uplift force.Mixed core conditions for assembly lift-off are considered on a cycle-specific basis, as determined by the plant and other fuel types. Analyses to date indicate a large margin to assembly lift-off under normal operating conditions. Therefore, fuel lift-off in BWRs under normal operating conditions is considered to be a small concern.For faulted conditions, the ATRIUM 1OXM design was evaluated for fuel lift considering the maximum flow conditions due to a pump flow run-out event and the additional differential pressure from a LOCA event. The net force on the fuel assembly was calculated considering contributions from gravity, hydraulic forces, momentum, and buoyancy. The criteria are satisfied since the calculated net force remains in the downward direction. The increase in hydraulic lift forces for the co-resident GE14 and ATRIUM-10 fuel due to the transition to ATRIUM 1OXM is negligible. []. The lift forces due to vertical seismic loads were also determined to be insufficient to lift a fuel assembly. The fuel will not lift and it will not become disengaged from the fuel support.For the same assembly, flow and power conditions; the pressure drops for Brunswick Unit 2 are greater than the pressure drops for Unit 1 due to smaller Unit 2 core inlet orifices. Thus, holddown values for Unit 2 can be considered bounding for Unit 1.3.3.9 Fuel Assembly Handling The fuel assembly shall withstand, without permanent deformation, all normal axial loads from shipping and fuel handling operations. Analysis or testing shall show that the fuel is capable of [The fuel assembly structural components are assessed for axial fuel handling loads by testing. To demonstrate compliance with the criteria, the test is performed by loading a test assembly to an axial AREVA NP Inc. Controlled Document AREVA NP ANP-2948NP Mechanical Design Report for Revision 0 Brunswick ATRIUM 1OXM Fuel Assemblies Page 14 tensile force greater than [ ]. An acceptable test shows no yielding after loading. The testing is described further in Section 4.1.There are also handling requirements for the fuel rod plenum spring which are addressed in the fuel rod design report.3.3.10 Miscellaneous Component Criteria 3.3.10.1 Compression Spring Forces The ATRIUM 1OXM has a single large compression spring mounted on the central water channel. The compression spring serves the same function as previous designs by providing support for the UTP and fuel channel. The spring force is calculated based on the deflection and specified spring force requirements. Irradiation-induced relaxation is taken into account for EOL conditions. The minimum compression spring force at EOL is shown to be greater than the combined weight of the UTP and fuel channel (including channel fastener hardware). Since the compression spring does not interact with the fuel rods, no consideration is required for fuel rod buckling loads.3.3.10.2 LTP Seal Spring The LTP seal spring shall limit the bypass coolant leakage rate between the LTP and fuel channel. The seal spring shall accommodate expected channel deformation while remaining in contact with the fuel channel. Also, the seal spring shall have adequate corrosion resistance and be able to withstand the operating stresses without yielding.Flow testing is used to confirm acceptable bypass flow characteristics. The seal spring is designed with adequate deflection to accommodate the maximum expected channel bulge while maintaining acceptable bypass flow. [ ] is selected as the material because of its high strength at elevated temperature and its excellent corrosion resistance. Seal spring stresses are analyzed using a finite element method.3.4 Fuel Coolability For accidents in which severe fuel damage might occur, core coolability and the capability to insert control blades are essential. Chapter 4.2 of the SRP provides several specific areas important to fuel coolability, as discussed below.3.4.1 Claddinq Embrittlement The LOCA evaluation is not part of the structural analysis.AREVA NP Inc. Controlled Document AREVA NP ANP-2948NP Mechanical Design Report for Revision 0 Brunswick ATRIUM 1 OXM Fuel Assemblies Page 15 3.4.2 Violent Expulsion of Fuel The LOCA evaluation is not part of the structural analysis.3.4.3 Fuel Ballooninq The LOCA evaluation is not part of the structural analysis.3.4.4 Structural Deformations Deformations or stresses from postulated accidents are limited according to requirements contained in the ASME B&PV Code, Section III, Division 1, Appendix F, and SRP Section 4.2, Appendix A. The limits for each structural. component are derived from analyses and/or component load tests.Testing is performed to obtain the dynamic characteristics of the fuel assembly and spacer grids. The stiffnesses, natural frequencies and damping values derived from the tests are used as inputs for analytical models of the fuel assembly and fuel channel. Fuel assemblies are tested with and without a fuel channel. In addition, the analytical models are compared to the test results to ensure an accurate characterization of the fuel. In general, the testing and analyses have shown the dynamic response of the ATRIUM 1 0XM design to be very similar to other BWR fuel designs that have the same basic channel configuration and weight. See Section 4.0 for descriptions of the testing.The methodology for analyzing the fuel under the influence of seismic/LOCA accident loads is described in Reference

2. Evaluations performed for the fuel under combined seismic/LOCA loadings include mechanical fracturing of the fuel rod cladding, assembly structural integrity, and fuel assembly liftoff.Restricting fuel uplift and limiting fuel channel deformation under accident conditions permit insertion of the control blades. Assembly liftoff under accident conditions is described in Section 3.3.8.The ATRIUM 1OXM design was analyzed under a limiting core plate time history supplied by Progress Energy for Brunswick Units 1 and 2. This time history was originally prepared for the introduction of the ATRIUM-10 using 100/75 AFC properties and an assembly mass slightly greater than ATRIUM-10.

The time history is the same for Brunswick Units 1 and 2. [AREVA NP Inc. Controlled Document AREVA NP ANP-2948NP Mechanical Design Report for Revision 0 Brunswick ATRIUM 1OXM Fuel Assemblies Page 16 1. Tables 3-1 and 3-2 list the minimum design margins for the fuel assembly structural components and fuel channel.As noted above, core excitations prepared for ATRIUM-1 0 are applicable to both ATRIUM-1 0 and ATRIUM 1OXM. Therefore, introduction of ATRIUM 1OXM fuel does not impact RPV and internals margin evaluations previously performed for introduction of ATRIUM-10. 3.4.4.1 Fuel Storage Seismic Qualification The High Density Spent Fuel Storage Racks (HDSFSR), New Fuel Storage (NFS), and the Fuel Preparation Machine (FPM) analyses account for the fuel as added mass in calculating the structural integrity under postulated seismic loads. The existing analyses take into account fuel designs with weights encompassing the weight of the ATRIUM 1OXM fuel design. Therefore, the HDSFSR, NFS, and FPM remain qualified with the introduction of the ATRIUM 1OXM fuel design.3.5 Fuel Channel and Fastener The fuel channel and fastener design criteria are summarized below, and evaluation results are summarized in Table 3-2 and Table 3-3. The analysis methods are described in detail in Reference 2.3.5.1 Design Criteria for Normal Operation Steady-State Stress Limits. The stress limits during normal operation are obtained from the ASME B&PV Code, Section III, Division 1, Subsection NG for Service Level A. The calculated stress intensities are due to the differential pressure across the channel wall. The pressure loading includes the normal operating pressure plus the increase during AOO. The unirradiated properties of the fuel channel material are used since the yield and ultimate tensile strength increase during irradiation. As an alternative to the elastic analysis stress intensity limits, a plastic analysis may be performed as permitted by paragraph NB-3228.3 of the ASME B&PV Code.In the case of AQOs, the amount of bulging is limited to that value which will permit control blade movement. During normal operation, any significant permanent deformation due to yielding is precluded by restricting the maximum stresses at the inner and outer faces of the channel to be less than the yield strength.Fuel Channel Fatigue. Cyclic changes in power and flow during operation impose a duty loading on the fuel channel. The cyclic duty from pressure fluctuations is limited to less than the fatigue lifetime of the fuel channel. The fatigue life is based on the O'Donnel and Langer curve (see Reference 5), which AREVA NP Inc. Controlled Document AREVA NP ANP-2948NP Mechanical Design Report for Revision 0 Brunswick ATRIUM 1 OXM Fuel Assemblies Page 17 includes a factor of 2 on stress amplitude or a factor of 20 on the number of cycles, whichever is more conservative. Corrosion and Hydrogen Concentration. Corrosion reduces the material thickness and results in less load-carrying capacity. The fuel channels have thicker walls than other components (e.g., fuel rods), and the normal amounts of oxidation and hydrogen pickup are not limiting provided: the alloy composition and impurity limits are carefully selected; the heat treatments are also carefully chosen; and the water chemistry is controlled. Because the amount of corrosion and the corresponding hydrogen pickup are relatively small, no specific limits are provided. []Long-Term Creep Deformation. Changes to the geometry of the fuel channel occur due to creep deformation during the long term exposure in the reactor core environment. Overall deformation of the fuel channel occurs from a combination of bulging and bowing. Bulging of the side walls occurs because of the differential pressure across the wall. Lateral bowing of the channel is caused primarily from the neutron flux and thermal gradients. Too much deflection may prevent normal control blade maneuvers and it may increase control blade insertion time above the Technical Specification limits. The total channel deformation must not stop free movement of the control blade.3.5.2 Desiqn Criteria for Accident Conditions Fuel Channel Stresses and Limit Load. The criteria are based on the ASME B&PV Code, Section III, Appendix F, for faulted conditions (Service Level D). Component support criteria for elastic system analysis are used as defined in paragraphs F-1332.1 and F-1332.2. The unirradiated properties of the fuel channel material are used since the yield and ultimate tensile strength increase during irradiation. Stresses are alternatively addressed by the plastic analysis collapse load criteria given in paragraph F-1332.2(b). For the plastic analysis collapse load, the permanent deformation is limited to twice the deformation the structure would undergo had the behavior been entirely elastic.The amount of bulging remains limited to that value which will permit control blade insertion. Fuel Channel Gusset Load Rating. [AREVA NP Inc. Controlje~gR~cument Mechanical Design Report for Brunswick ATRIUM 1OXM Fuel Assemblies ANP-2948NP Revision 0 Page 18 Table 3-1 Results for ATRIUM 1OXM Fuel Assembly Criteria Section Description Criteria Results 3.3 Fuel System Criteria 3.3.1 Stress, strain and loading limits on assembly components .Water channel Fatigue Fretting wear Oxidation, hydriding, and crud buildup Rod bow The ASME B&PV Code Section III is used to establish acceptable stress levels or load limits for assembly structural components. The design limits for accident conditions are derived from Appendix F of Section Ill.Protect thermal limits I I.3.3.2 3.3.3 3.3.4 3.3.5..I.AREVA NP Inc. Cortro-ied Document AREVA NP Mechanical Design Report for Brunswick ATRIUM 1OXM Fuel Assemblies ANP-2948NP Revision 0 Page 19 Table 3-1 Results for ATRIUM 1OXM Fuel Assembly (Continued) Criteria Section Description Criteria Results 3.3 Fuel System Criteria (Continued) 3.3.6 3.3.7 3.3.8 3.3.9 3.3.10 3.3.10.1 3.3.10.2 Axial irradiation growth" Upper end cap clearance" Seal spring engagement Rod internal pressure Assembly liftoff" Normal operation (including AQOs)" Postulated accident Fuel assembly handling Miscellaneous components Compression spring forces LTP seal spring Clearance always exists Remains engaged with channel N/A No liftoff from fuel support No disengagement from fuel support. No liftoff from fuel support.Support weight of UTP and fuel channel throughout design life Accommodate fuel channel deformation, adequate corrosion, and withstand operating stresses I[Not covered report I in structural [[The design criteria are met.The design criteria are met.AREVA NP Inc. Controlled Document AREVA NP Mechanical Design Report for Brunswick ATRIUM 1OXM Fuel Assemblies ANP-2948NP Revision 0 Page 20 Table 3-1 Results for ATRIUM 1OXM Fuel Assembly (Continued) Criteria Section Description Criteria Results 3.4 Fuel Coolability 3.4.1 3.4.2 3.4.3 3.4.4 Cladding embrittlement Violent expulsion of fuel Fuel ballooning Structural deformations Fuel rod stresses Spacer grid lateral load Water channel load UTP lateral load LTP lateral load N/A N/A N/A Maintain coolable geometry and ability to insert control blades. SRP 4.2, App. A, and ASME Section III, App. F.[[[[[Not covered in structural report Not covered in structural report Not covered in structural report See results below for individual components. Results are based on a limiting time history.I AREVA NP Inc. Controlled Document AREVA NP Mechanical Design Report for Brunswick ATRIUM 10XM Fuel Assemblies ANP-2948NP Revision 0 Pace 21 Table 3-2 Results for Advanced Fuel Channels Criteria Section Description Criteria Results 3.5.1 Advanced Fuel Channel -Normal Operation Stress due to The pressure load including AOO The deformation during AOO pressure differential is limited to [ remains within functional limits] according for normal control blade to ASME B&PV Code, Section III. operation and the collapse load The pressure load is also limited requirement is met with [such that [ ]. There is no significant plastic deformation during normal]. operation [Fatigue Cumulative cyclic loading to be Expected number of cycles less than the design cyclic fatigue [ ] is less than life for Zircaloy. [ allowable. ].Oxidation and Oxidation shall be accounted for The maximum expected hydriding in the stress and fatigue analyses oxidation is low in relation to the wall thickness. Oxidation was accounted in the stress and fatigue analyses.Long-term Bulge and bow shall not interfere Margin to a stuck control blade deformation (bulge with free movement of the control remains positive.creep and bow) blade AREVA NP Inc. Controlled Document AREVA NP Mechanical Design Report for Brunswick ATRIUM 1QXM Fuel Assemblies ANP-2948NP Revision 0 Pagqe 22 Table 3-2 Results for Advanced Fuel Channels (Continued) Criteria Section Description Criteria Results 3.5.2 Advanced Fuel Channel -Accident Conditions Fuel channel The pressure load is limited to The deformation during stresses and load [ blowdown does not interfere limit ] according to ASME B&PV with control blade insertion [Code, Section Ill, App. F. The pressure load is also limited such that [].Channel bending Allowable bending moment from combined based on ASME Code, horizontal Section IfI, Appendix F plastic excitations analysis collapse load Fuel channel gusset ASME allowable load rating of strength one gusset is [].]1.AREVA NP Inc. Controlled Document AREVA NP Mechanical Design Report for Brunswick ATRIUM 10XM Fuel Assemblies ANP-2948NP Revision 0 Pa~qe 23 Table 3-3 Results for Channel Fasteners Criteria Section Description Criteria Results 3.5 Channel Fastener Compatibility Spring height must extend to All compatibility requirements the middle of the control cell to are met. The spring will extend ensure contact with adjacent beyond the cell mid-line.spring.Spring axial location must be The axial location of the spring sufficient to ensure alignment flat will always be in contact with adjacent spring at all with an adjacent spring; even if exposures. a fresh ATRIUM 10XM is placed adjacent to an EOL co-resident assembly.Strength Spring must meet ASME All ASME stress criteria are met stress criteria and not yield for the spring and cap screw.beyond functional limit. In addition, the spring will not yield under the maximum Cap screw must meet ASME deflection. criteria for threaded fastener.AREVA NP Inc. Contro=Rj jD cument ANP-2948NP Mechanical Design Report for Revision 0 Brunswick ATRIUM 1OXM Fuel Assemblies Page 24 4.0 Mechanical Testing Prototype testing is an essential element of AREVA's methodology for demonstrating compliance with structural design requirements. Results from design verification testing may directly demonstrate compliance with criteria or may be used as input to design analyses.Testing performed to qualify the mechanical design or evaluate assembly characteristics includes: " Fuel assembly axial load structural strength test* Spacer grid lateral impact strength test* Tie plate lateral load strength tests and LTP axial compression test" Debris filter efficiency test" Fuel assembly fretting test" Fuel assembly static lateral deflection test" Fuel assembly lateral vibration tests* Fuel assembly impact tests Summary descriptions of the tests are provided below.4.1 Fuel Assembly Axial Load Test An axial load test was conducted by applying an axial tensile load between the LTP grid and UTP handle of a fuel assembly cage specimen. The load was slowly applied while monitoring the load and deflection. No significant permanent deformation was detected for loads in excess [4.2 Spacer Grid Lateral Impact Strength Test Spacer grid impact strength was determined by a [AREVA NP Inc. C o ntro 11iv,,~cu ume nt Mechanical Design Report for Brunswick ATRIUM 1OXM Fuel Assemblies ANP-2948NP Revision 0 Pape 25 The maximum force prior to the onset of buckling was determined from the testing. The results were adjusted to reactor operating temperature conditions to establish an allowable lateral load.4.3 Tie Plate Strength Tests In addition to the axial tensile tests described above, a lateral load test is performed on the UTP and LTP, and a compressive load test is performed on the LTP.The UTP lateral load test was conducted on a test machine which applied an increasing load until a measurable amount of plastic deformation was detected. This provides a limiting lateral load for accident conditions. []1.For the Improved FUELGUARD LTP compressive load test, the tie plate was supported by the nozzle to simulate the fuel support conditions. A uniform, compressive axial load was applied to the grid. [].To determine a limiting lateral load for accident conditions, the LTP lateral load test was conducted by attaching the grid of the tie plate to a rigid vertical plate and applying a side load to the cylindrical part of the nozzle. [I.4.4 Debris Filter Efficiency Test Debris filtering tests were performed for the Improved FUELGUARD lower tie plate to evaluate its debris filtering efficiency. These tests evaluated the ability of the Improved FUELGUARD to protect the fuel rod array from a wide set of debris forms. In particular, testing was performed using small filamentary debris (e.g., wire brush debris) as this form is known to be a cause of debris fretting fuel failures. When testing the small filamentary debris forms, the debris filter is placed in a hydraulic test loop above a debris chamber. After insertion of a debris set in the debris chamber, the loop pump is started to circulate water AREVA NP Inc. Controlled Document AREVA NP ANP-2948NP Mechanical Design Report for Revision 0 Brunswick ATRIUM IOXM Fuel Assemblies Page 26 in the loop for a given amount of time. Multiple pump shutdowns and restarts are then simulated. At the end of the test, the location of all debris is recorded and the filtering efficiency is determined. These debris filtering tests demonstrate that the Improved FUELGUARD is effective at protecting the fuel rod array from all high-risk debris forms.4.5 Fuel Assembly Fretting Test A fretting test was conducted on a full-size test assembly to evaluate the ATRIUM 1OXM fuel rod support design. Spacer springs were relaxed in selected locations to simulate irradiation relaxation. []. After the test, the assembly was inspected for signs of fretting wear. No significant wear was found on fuel rods in contact with spacer springs relaxed to EOL conditions. The results agree with past test results on BWR designs where no noticeable wear was found on the fuel rods or other interfacing components following exposure to coolant flow conditions. 4.6 Fuel Assembly Static Lateral Deflection Test A lateral deflection test was performed to determine the fuel assembly stiffness, both with and without the fuel channel. The stiffness is obtained by supporting the fuel assembly at the two ends in a vertical position, applying a side displacement at the central spacer location, and measuring the corresponding force. Results from this test are input to the fuel assembly structural model for seismic analysis.4.7 Fuel Assembly Lateral Vibration Tests The lateral vibration testing consists of both a free vibration test and a forced vibration test []. Results from these tests are used as input to the fuel assembly structural model for seismic analysis.The test setup for the free vibration test is similar to the lateral deflection test described above. The fuel assembly is deflected to a specific displacement and then released. Displacement data are recorded at several spacer locations. The assembly natural frequencies and damping ratios are derived from the recorded motion. The test is repeated for several initial displacements. The forced vibration testing [AREVA NP Inc. Controlled Document AREVA NP Mechanical Design Report for Brunswick ATRIUM 1OXM Fuel Assemblies ANP-2948NP Revision 0 Paqe 27 4.8 Fuel Assembly Impact Tests Impact testing was performed in a similar manner to the lateral deflection test. The unchanneled assembly is supported in a vertical position with both ends fixed. The assembly is displaced a specified amount and then released. A load cell is fixed to a rigid structure and located adjacent to a mid-assembly spacer. The fuel assembly impacts the load cell and the resulting impact force is recorded as a function of the initial displacement. The measured impact loads are used in establishing the spacer grid stiffness. AREVA NP Inc. Controlled Document AREVA NP ANP-2948NP Mechanical Design Report for Revision 0 Brunswick ATRIUM 1OXM Fuel Assemblies Page 28 5.0 References

1. ANF-89-98(P)(A)

Revision 1 and Supplement 1, Generic Mechanical Design Criteria for BWR Fuel Designs, Advanced Nuclear Fuels Corporation, May 1995.2. EMF-93-177(P)(A) Revision 1, Mechanical Design for BWR Fuel Channels, Framatome ANP Inc., August 2005.3. EMF-85-74(P) Revision 0 Supplement 1(P)(A) and Supplement 2(P)(A), RODEX2A (BWR) Fuel Rod Thermal-Mechanical Evaluation Model, Siemens Power Corporation, February 1998.4. XN-NF-75-32(P)(A) Supplements 1 through 4, Computational Procedure for Evaluating Fuel Rod Bowing, Exxon Nuclear Company, October 1983. (Base document not approved.)

5. W. J. O'Donnell and B. F. Langer, "Fatigue Design Basis for Zircaloy Components," Nuclear Science and Engineering, Volume 20, January 1964.AREVA NP Inc.

Controlld Document AREVA NP Mechanical Design Report for Brunswick ATRIUM 1OXM Fuel Assemblies ANP-2948NP Revision 0 Page 29 Appendix A Illustrations The following table lists the fuel assembly and fuel channel component illustrations in this section: Description Page ATRIUM 1OXM Fuel Assembly 30 UTP with Locking Hardware 31 Improved FUELGUARD LTP 32 ATRIUM 1OXM ULTRAFLOW Spacer Grid 33 Fuel and Part-Length Fuel Rods 34 Advanced Fuel Channel 35 Fuel Channel Fastener Assembly 36 These illustrations are for descriptive purpose only. Please refer to the current reload design package for product dimensions and specifications. AREVA NP Inc. Controlled Document AREVA NP Mechanical Design Report for Brunswick ATRIUM 1OXM Fuel Assemblies ANP-2948NP Revision 0 Page 30 fsjm03308 I I Figure A-1 ATRIUM 1OXM Fuel Assembly (not to scale)AREVA NP Inc. Controlled Dcument Mechanical Design Report for Brunswick ATRIUM 1OXM Fuel Assemblies ANP-2948NP Revision 0 Page 31 fsjm03010 I I Figure A-2 UTP with Locking Hardware AREVA NP Inc. Con troled DocumeA AREVA NP Mechanical Design Report for Brunswick ATRIUM 10XM Fuel Assemblies AN P-2948NP Revision 0 Page 32 fsjmOO21 0 Figure A-3 Improved FUELGUARD LTP AREVA NP Inc. Contlo .d Documen AREVA NP Mechanical Design Report for Brunswick ATRIUM 10 XM Fuel Assemblies ANP-2948NP Revision 0 Page 33 fsjm03708 I Figure A-4 ATRIUM 1OXM ULTRAFLOW Spacer Grid AREVA NP Inc. Controk ~cument Mechanical Design Report for Brunswick ATRIUM 1OXM Fuel Assemblies ANP-2948NP Revision 0 Pagqe 34 fsjmOO3i 0 fsjmOO41 0 Figure A-5 Full and Part-Length Fuel Rods (not to scale)AREVA NP Inc. Controllo~taE9cument Mechanical Design Report for Brunswick ATRIUM 1OXM Fuel Assemblies ANP-2948NP Revision 0 Page 35 fsjm 00905 Figure A-6 Advanced Fuel Channel AREVA NP Inc. ControIgp.tgjclu ment Mechanical Design Report for Brunswick ATRIUM 1OXM Fuel Assemblies ANP-2948NP Revision 0 Pagqe 36 fsjm3O36 Figure A-7 Fuel Channel Fastener Assembly AREVA NP Inc. BSEP 10-0126 Enclosure 5 AREVA Affidavit Regarding Withholding ANP-2956(P), Revision 0, from Public Disclosure AFFIDAVIT STATE OF WASHINGTON )) ss.COUNTY OF BENTON )1. My name is Alan B. Meginnis. I am Manager, Product Licensing, for AREVA NP Inc. and as such I am authorized to execute this Affidavit.

2. I am familiar with the criteria applied by AREVA NP to determine whether certain AREVA NP information is proprietary.

I am familiar with the policies established by AREVA NP to ensure the proper application of these criteria.3. I am familiar with the AREVA NP information contained in the report ANP-2956(P) Revision 0, entitled, "Brunswick Unit 2 Cycle 20 Reload Safety Analysis," dated October 2010 and referred to herein as "Document." Information contained in this Document has been classified by AREVA NP as proprietary in accordance with the policies established by AREVA NP for the control and protection of proprietary and confidential information.

4. This Document contains information of a proprietary and confidential nature and is of the type customarily held in confidence by AREVA NP and not made available to the public. Based on my experience, I am aware that other companies regard information of the kind contained in this Document as proprietary and confidential.

5. This Document has been made available to the U.S. Nuclear Regulatory Commission in confidence with the request that the information contained in this Document be withheld from public disclosure.

The request for withholding of proprietary information is made in accordance with 10 CFR 2.390. The information for which withholding from disclosure is requested qualifies under 10 CFR 2.390(a)(4) "Trade secrets and commercial or financial information." 6. The following criteria are customarily applied by AREVA NP to determine whether information should be classified as proprietary: (a) The information reveals details of AREVA NP's research and development plans and programs or their results.(b) Use of the information by a competitor would permit the competitor to significantly reduce its expenditures, in time or resources, to design, produce, or market a similar product or service.(c) The information includes test data or analytical techniques concerning a process, methodology, or component, the application of which results in a competitive advantage for AREVA NP.(d) The information reveals certain distinguishing aspects of a process, methodology, or component, the exclusive use of which provides a competitive advantage for AREVA NP in product optimization or marketability.(e) The information is vital to a competitive advantage held by AREVA NP, would be helpful to competitors to AREVA NP, and would likely cause substantial harm to the competitive position of AREVA NP.The information in the Document is considered proprietary for the reasons set forth in paragraphs 6(b), 6(d) and 6(e) above.7. In accordance with AREVA NP's policies governing the protection and control of information, proprietary information contained in this Document have been made available, on a limited basis, to others outside AREVA NP only as required and under suitable agreement providing for nondisclosure and limited use of the information.

8. AREVA NP policy requires that proprietary information be kept in a secured file or area and distributed on a need-to-know basis.

9. The foregoing statements are true and correct to the best of my knowledge, information, and belief.SUBSCRIBED before me this day of 2010. _Susan K. McCoy NOTARY PUBLIC, STATE OF.WASHfr MY COMMISSION EXPIRES: "1/10/12 ,N}}