ANP-10334NP, Revision 0, 'Q12 Structural Material, Topical ... · AREVA Inc. ANP-1 0334NP Revision 0 Q12TM Structural Material Topical Report Paqe 1-1 1.0 INTRODUCTION AREVA has developed

AARE VA

Q12TM Structural Material ANP-10334NPRevision 0

Topical Report

October 2015

AREVA Inc.

(c) 2015 AREVA Inc.

ANP-1 0334NPRevision 0

Copyright © 2015

AREVA Inc.All Rights Reserved

AREVA Inc. ANP-1 0334NPRevision 0

QI2 TM Structural MaterialTopical Report Pacqei

Nature of Changes

Section(s)Item or Page(s) Description and Justification1 All Initial Issue

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Q12TM Structural MaterialTopical Report Pacqe ii

Contents

1.0 INTRODUCTION ...................................................................... 1-1

2.0 SUMMARY............................................................................. 2-1

3.0 APPLICABLE REGULATORY GUIDANCE......................................... 3-1

4.0 MATERIAL DEFINITION ............................................................. 4-1

4.1 Material Composition.......................................................... 4-1

4.2 Microstructure........ .......................................................... 4-2

4.3 Manufacturing.................................................................. 4-2

5.0 IRRADIATION EXPERIENCE........................................................ 5-1

6.0 PHYSICAL PROPERTIES............................................................ 6-1

6.1 Melting Point ................................................................... 6-1

6.2 Density.......................................................................... 6-1

6.3 Heat Capacity.................................................................. 6-2

6.4 Thermal Expansion............................................................ 6-3

6.5 Thermal Conductivity.......................................................... 6-3

6.6 Young's Modulus .............................................................. 6-4

6.7 Poisson's Ratio ................................................................ 6-5

7.0 MECHANICAL BEHAVIOR OF Q12 TM ................ . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7-1

7.1 Tensile Properties of Unirradiated Material ................................. 7-1

7.2 Tensile Properties of Irradiated Material..................................... 7-2

7.3 Fatigue Properties............................................................. 7-2

8.0 OXIDATION AND HYDROGEN PICKUP ........................................... 8-1

8.1 Basis of Q12 TM Oxidation and Hydrogen Pickup Models .................. 8-2

8.1.1 Fuel Cladding Oxidation............................................... 8-28.1.2 Corrosion Sample in Reactor D24.................................... 8-28.1.3 Creep Sample in Reactor D24 ....................................... 8-38.1.4 Fuel Rod Plenum Region Samples in Reactor D71 ................ 8-48.1.5 Grid Oxide Measurements............................................ 8-4

8.2 Q12TM Guide Tube Oxidation Model............ ............................. 8-5

8.3 Spacer Grid Oxidation Model................................................. 8-6

8.4 Hydrogen Pickup Model....................................................... 8-6

9.0 FREE GROWTH AND CREEP....................................................... 9-1


QI2 TM Structural MaterialTopical Report Paqe iii

9.1 Q12TM Alloy Free Growth ..................................................... 9-19.1.1 Irradiation in BOR-60 .................................................. 9-19.1 .2 Irradiation in Reactor D24............................................. 9-29.1.3 Q12 TM Free Growth Model............................................ 9-29.1.4 Q12 TM Free Growth - Hydrogen Effects ............................ 9-3

9.2 Q12 TM Alloy Creep............................................................. 9-49.2.1 Irradiation in Reactor D24............................................. 9-49.2.2 Irradiation in BOR-60.................................................. 9-59.2.3 Q12TM Creep Model ................................................... 9-6

10.0 GROWTH CORRELATIONS........................................................ 10-1

10.1 Fuel Assembly Growth Correlation......................................... 10-1

10.2 Q12 TM Spacer Grid Growth Correlation.................................... 10-2

11.0 SURVEILLANCE..................................................................... 11-1

11.1 U.S. Surveillance .............................. ....................... :....... 11-1

11.2 European Surveillance....................................................... 11-1

12.0 UPDATE PROCESS................................................................. 12-1

12.1 Fuel Assembly Growth Model............................................... 12-1

12.2 Spacer Grid Growth Model .......................................... ,....... 12-2

12.3 NRC Notification......................................................... :.....12-2

13.0 REFERENCES ........................................................................ 13-1


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List of Tables

Table 3-1 Applicable Standard Review Plan Criteria and Associated Q12TMStructural Material Input for Design Evaluation ............................ 3-3

Table 4-1 Chemical Composition of Q12 TM Quaternary Alloy .......................... 4-3Table 4-2 Kearns Factors for Q12 TM and M5®............................................ 4-4

Table 5-1 Summary of Q12 TM Cladding Experience .................................... 5-2

Table 5-2 Summary of Q12 TM Guide Tube and Grid Experience....................... 5-3Table 7-1 Tensile Properties of Unirradiated Q12 TM and M5® Tubing at Room

Temperature.................................................................. 7-3Table 7-2 Tensile Properties of Unirradiated Q12 TM and M5® Tubing at 315°C......7-4Table 7-3 Tensile Properties of Unirradiated Q12 TM and M5® Tubing at 400°C ...... 7-5

Table 7-4 Tensile Properties of Unirradiated Q12 TM and M5® Sheet at RoomTemperature.................................................................. 7-6

Table 7-5 Tensile Properties of Unirradiated Q12TM and MS® Sheet at 340°C ........ 7-7

Table 7-6 Tensile Properties of Irradiated Q12 TM Fuel Cladding at ElevatedTemperature.................................................................. 7-8

Table 8-1 Oxide Thickness and Hydrogen Content Measurements forCorrosion, Creep, and Plenum Samples ................................... 8-8

Table 9-1 Coefficients for Q12TM Free Growth Model................................... 9-7

Table 11-1 PIE Plan for Lead Assemblies in Reactor B42 ............................ 11-2

Table 11-2 PIE Plan for Lead Assemblies in Reactor B40 ............................ 11-3

Table 11-3 PIE Plan for European Lead Assemblies in 2015 ......................... 11-4


Q12 TM Structural MaterialTopical Report Pa~qe v

List of FiguresFigure 4-1 Optical Microscopy of M5® and Q12 TM Microstructures .................... 4-5

Figure 4-2 Distribution of Precipitates in M5® and Q12 TM Microstructures............. 4-6

Figure 4-3 Q12TM Fabrication Process Outline........................................... 4-7

Figure 6-1 Young's Modulus Measurements and Model .......... ..................... 6-6

Figure 7-1 Fatigue Data and Model....................................................... 7-9

Figure 8-1 Flowchart for Development of Q12TM Oxidation Models.................... 8-9

Figure 8-2 Flowchart for Development of Q12 TM Hydriding Model.................... 8-10

Figure 8-3 Geometry of Crevice Corrosion Sample.................................... 8-11

Figure 8-4 Q12TM Spacer Grid Oxide Thickness Measurements after Two,Three, and Four Annual Cycles of Irradiation ............................ 8-12

Figure 8-5 Comparison between Measurements and Predictions for theOxidation Model Developed for Q12 TM Cladding......................... 8-13

Figure 8-6 Comparison between Measurement and Prediction for the OxidationModel for QI2TM Guide Tubes............................................. 8-14

Figure 8-7 Comparison between Measurement and Prediction for the OxidationModel Developed for Q12 TM Grids......................................... 8-15

Figure 8-8 Comparison between Measurement and Prediction for the HydrogenPickup Model Developed for Q12 TM Guide Tubes and Spacer Grids ... 8-16

Figure 9-1 Free Growth versus Fluence - Comparison of Results from BOR-60and D24....................................................................... 9-8

Figure 9-2 Schematic of Axial Creep and Free Growth Material Test Rods ........... 9-9

Figure 9-3 Free Growth versus Fluence: (a) Full Range of Data; (b) Detail forFluences < 20 E+25 n/m2.................................................. 9-10

Figure 9-4 Comparison of Q12TM Free Growth for Fresh and Pre-HydridedSpecimens .......... ....................................................... 9-11

Figure 9-5 QI2 TM and M5® Creep - D24 Reactor Irradiation (10 MPaCompression)............................................................... 9-12

Figure 9-6 Q12 TMand MS® Creep - BOR-60 Irradiation (20 MPa Tension) .......... 9-13

Figure 9-7 Q12 TM and MS® Creep - BOR-60 Irradiation (40 MPa Tension).......... 9-14

Figure 9-8 Q12TM Normalized Creep Strain - BOR-60 and D24 ReactorIrradiation.................................................................... 9-15

Figure 9-9 Comparison of Q12TM Axial Creep Predictions and ExperimentalResults....................................................................... 9-16


Q12TM Structural MaterialTopical Report Paae vi

Figure 9-10

Figure 10-1

Figure 10-2

Comparison between Q12 TM Axial Creep Predictions andExperimental Results ........................................................ 9-17

Q12 TM Fuel Assembly Growth Data and Design Limits................... 10-4

Upper Design Limit for Q12 TM Grid Growth Using M5® and QI2 TM

Grid Growth Data............................................................. 10-5

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Nomenclature

(If applicable)

Acronym Deftinition

AOOs Anticipated Operational OccurrencesFA Fuel Assembly

GT Guide Tube

LDL Lower Design Limit

MTRs Material Test Rods

NRC Nuclear Regulatory Commission

PIE Post-Irradiation Examination

PWR Pressurized Water Reactor

RCCA Rod Cluster Control Assembly

SRP Standard Review Plan for the Review of Safety Analysis Reports forNuclear Power Plants

TE Total Elongation

UDL Upper Design Limit

UE Uniform Plastic Elongation

UTS Ultimate Tensile Strength

YS Yield Strength


QI2 TM Structural MaterialTopical Report Paqe viii

ABSTRACT

The purpose of this topical report is to present the material definition and material

characteristics for a new structural alloy, Q12 TM . Q12TM is an alloy composed of

zirconium, niobium, iron and tin. The Q12 TM material is intended for use in fuel assembly

structural components (guide tubes, instrument tubes and spacer grids.)

A discussion is presented of the current regulatory guidance related to structural

material. This guidance is found primarily in NUREG-0800 Chapter 4.2. A comparison of

applicable NUREG-0800 Chapter 4.2 criteria and the design evaluation input for the

Q12TM material is provided.

The composition of the Q12T material is defined. The Q12T microstructure and

manufacturing process is described.

The irradiation experience with the 012TM material to-date is summarized. Fuel

assemblies with Q12T cladding, guide tubes and spacer grids have been irradiated.

While Q12T will not be used for cladding the irradiation experience provides information

about the material behavior.

The physical properties, mechanical behavior, oxidation and hydrogen pick-up fractions

are defined. The information that will be used in design evaluations is summarized.

The free growth and creep behavior of Q12Th is presented. This information is not used

in design evaluations but is presented to demonstrate that Q12TM behavior is well

understood and predictable.

The Q12TM fuel assembly and grid growth correlations are presented. The correlations

are empirical in nature. The fuel assembly growth is an area in which Q12TM represents

a significant improvement over the behavior of M5® as a structural material.


Q12TM Structural MaterialTopical Report Paqe ix

The plans for surveillance of the Q12TM structural material behavior are presented.

Surveillance is planned for fuel assemblies under irradiation in both Europe and the

United States.

An update process is defined to support changes to the Q12TM characteristics that are

input to the design evaluations. This update process involves notification to the NRC

under defined conditions. The update process defines the conditions under which the

fuel assembly growth correlation can be updated based on the collection of additional

fuel assembly growth data.

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1.0 INTRODUCTION

AREVA has developed a new zirconium alloy, building on its expertise with M5®. This

alloy, Q1 2 TM, contains increased levels of iron and tin and is manufactured following the

same fabrication process that is used for M5®. The compositional changes result in a

zirconium alloy [ ] while

demonstrating an increased resistance to creep. This creep resistance (important for

fuel assembly growth) is accompanied by acceptable corrosion performance for

structural components.

Improving fuel assembly (FA) growth characteristics requires a combination of design-

specific and materials-specific solutions. In this context, AREVA undertook a research

and development program to assess the contribution of structural components

fabricated from ultra-low tin Zr-I1%Nb-Sn-Fe quaternary alloys. The Q12 TM alloy was

among those studied. This topical report presents Q12TM as a materials-specific solution

that contributes to control of FA growth.

Q12TM is intended for use as a structural material and, as such, will be used to

manufacture guide tubes, instrument tubes, and grids. Q12TM samples have been

through a rigorous test program to establish the material properties of the alloy.

Components made from Q12TM have undergone irradiation in lead assemblies and

batch fuel at a variety of PWR units worldwide. Fuel assemblies with Q12 TM guide tubes

and grids have achieved a fuel assembly average burnup of [ ] GWd/mtU. Post-

irradiation examinations of these components have demonstrated that Q12TM performs

in a stable, predictable manner.


Q1 2 TM Structural MaterialTopical Report Paqe 1-2

Section 3.0 discusses the regulatory requirements of the Standard Review Plan and

how those pertain to a structural zirconium alloy. Section 4.0 provides a definition of

QI2TM including its composition and microstructural state. AREVA's irradiation

experience with Q1 2TM iS provided in Section 5.0. The physical and mechanical

properties of Q12 TM are provided in Sections 6.0 and 7.0, respectively. Section 8.0provides the oxidation and hydrogen pickup models for Q12TM components. Q12 TM

creep and free growth are discussed in Section 9.0, with.the resulting growth models

presented in Section 10.0. AREVA's planned ongoing surveillance is covered in Section

11.0. Finally, an update process to address modification to the models contained within

this report in order to address future data is discussed in Section 12.0.


QI2 TM Structural MaterialTopical Report Paqe 2-1

2.0 SUMMARY

This topical report provides the test results and reactor performance of Q12TM and

provides the models needed to design structural components using the QI2TM alloy.

Additionally, an update process is defined which facilitates AREVA's ability to monitor

future performance of Qi12TM and update the models as necessary.

The following strategy is used to demonstrate that Q12TM is suitable for use in FAs:

* The Standard Review Plan (SRP) (Reference 1) is reviewed to determine the criteria

that apply to guide tubes, instrument tubes, and grids.

*A definition of QI2 TM is provided, in terms of both composition and manufacturing

processes. The definition provides confidence Q12TM will retain its distinctive

characteristics and that the future performance of QI2TM will be consistent with the

available experience.

* The materials-related input for design evaluations of these components is identified.

Some of the input, such as density and the coefficient of thermal expansion, is used

directly in analytical models. Values or equations for the input, based on laboratory

measurements, are provided. Other input, such as corrosion rate and FA growth,

can only be determined by irradiation tests. Empirical correlations, based on

irradiation experience, are provided. All of the materials-related input needed to

show compliance with the Standard Review Plan is discussed.

* Additional information is provided to demonstrate a thorough understanding of the

material. Examples are information about the microstructure, free growth, and

irradiation creep. Such information is not explicitly used in design calculations, but it

provides assurance that the intrinsic properties of Q12TM are thoroughly understood

and that the performance of FAs with Q12TM components can be predicted

accurately.

* Irradiation experience and surveillance plans for FAs with QI2TM components are

summarized. Experience provides assurance that Q12TM provides consistent


Q12TM Structural MaterialTopical Report Panqe 2-2

performance, for both guide tubes and grids, in a variety of FA designs. Surveillance

ensures that any changes in performance will be promptly detected, and, if

necessary, appropriate actions can be taken.

Because QI 2 TM is an evolutionary development of the current M5® alloy, it benefits from

the extensive industrial experience already gained. The Q12TM alloy is processed in the

same way as M5®; the two alloys differ only by the addition of a small amount of tin (Sn)

and slightly increased iron (Fe) content. For structural components these modifications

provide higher irradiation creep strength accompanied by acceptable corrosion

performance. Fuel assemblies with quaternary alloy guide tubes are expected to

demonstrate increased robustness with respect to FA bow, have improved growth

characteristics, and maintain high burnup capability.

Q12TM has been irradiated in [ ] reactors and has reached assembly average

burn ups of [ ] GWd/mtU. It has been used for guide tubes and grids in several fuel

assembly designs. The basic material properties have been determined through various

in-core and out-of-core test programs. The performance of Q12TM has been measured

through many post-irradiation examinations and continues to show consistent,

predictable behavior. AREVA has developed models to predict the fuel assembly

behavior when Q12TM is used as a guide tube or grid material; these models are

presented here.

The criteria of Section 4.2 of the Standard Review Plan remain applicable to fuel

assemblies utilizing Q12 TM structural components. AREVA will use approved

methodologies to design and analyze fuel assemblies with Q12 TM guide tubes or grids.The material specific input and models necessary to support AREVA's NRC approved

methodologies are presented in this report. Throughout this report, models are provided

for Q12 TM guide tubes. Because of the similarity between guide tubes and instrument

tubes, these models are also applicable to Q12TM instrument tubes.


Q12 TM Structural MaterialTopical Report Paqe 3-1

3.0 APPLICABLE REGULATORY GUIDANCE

Regulatory guidance for the review of fuel system designs and adherence to applicable

General Design Criteria is provided in NUREG-0800, "Standard Review Plan for the

Review of Safety Analysis Reports for Nuclear Power Plants", Section 4.2, "Fuel System

Design" (Reference 1). In accordance with the Standard Review Plan Section 4.2, the

objectives of the fuel system safety review are to provide assurance that:

* The fuel system is notdamaged as a result of normal operation and anticipated

operational occurrences (AOOs).

* Fuel system damage is never so severe as to prevent control rod insertion when it is

required.

* The number of fuel rod failures is not underestimated for postulated accidents, and

* Fuel coolability is always maintained.

The implementation of the Q12TM zirconium alloy for pressurized water reactor (PWR)

structural material applications utilizes the applicable fuel design criteria from the above

section of NUREG-0800. Restricting the use of Q12 TM to guide tubes, instrument tubes,

and spacer grids significantly narrows the applicable SRP fuel design criteria. A review

of SRP Sections 4.3 and 4.4 criteria shows that these criteria are unaffected by the use

of Q1 2 TM for guide tubes, instrument tubes, and spacer grids. Only the SRP fuel design

criteria from Section 4.2 are germane to the structural material applications of Q12TM

alloy.

The use of QI2TM for fuel assembly guide tubes, instrument tubes, and spacer grids

does not inherently alter any existing fuel design criteria and methods previously used.

The structural material applications only require revision of material and mechanical

properties and applicable performance correlations/models as input into the appropriate

fuel design evaluations. Table 3-1 provides a summary of the applicable SRP criteria

and associated material input that may be used to perform the design evaluations to

assure compliance.


Q12 TM Structural MaterialTopical Report Pagqe 3-2

Approved NRC fuel design criteria and methods remain valid and will be used with the

Q12TM alloy properties, correlations, and models provided in this report. Application of

Q12 TM is limited to the NRC approved burnup limits for AREVA fuel design criteria and

methods.


Q12TM Structural MaterialTopical Reoort P~nF• 3.-3

Table 3-1 Applicable Standard Review Plan Criteria and AssociatedQ12 TM Structural Material Input for Design Evaluation

Applicable SRP Criteria Design Evaluation Input Repatornthi

SRP 4.2 Fuel System Design

I1. Acceptance Criteria

1. Design Bases

A. Fuel System Damage

Tensile properties (unirradiated and Sections 7.1 and 7.2i. Stress, strain, or irradiated)

loading limits Young's modulus Section 6.6

Poisson's ratio Section 6.7

ii. Cumulative strain Section 7.3fatigue cycle Fatigue properties

Adherence to applicable design-specific endurance testing and/oroperating experience

iii. Fretting wear Tensile properties (unirradiated and Sections 7.1 and 7.2irradiated)

Coefficient of thermal expansion Section 6.4

Material creep properties Section 9.2

iv. Oxidation, hydriding, Oiainhdoecreltns Section 8.0crudOxdto/yrgncreais

Coefficient of thermal expansion Section 6.4

Fuel assembly growth correlation Section 10.1v. Dimensional changes Sae rdgot orlto

Spacr gid gowt corelaion Section 10.2Material creep properties Section 9.2

Fuel assembly growth correlation Section 10.1

vii. Assembly liftoff Coefficient of thermal expansion Section 6.4

Density Section 6.2

Tensile properties (unirradiated and Sections 7.1 and 7.2viii. Control rod irradiated)

insertability Young's modulus Section 6.6

Material creep properties Section 9.2



1. Design Bases

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Applicable SRP Criteria Design Evaluation Input Locatonrnthi

C. Fuel coolability

v. Gross structuraldeformation

Appendix A: Evaluation of FuelAssembly Structural Response toExternally Applied Load

Ill. Determination of Strength

Adherence to design-specific spacer1. Gridsgrid test protocol

Tensile properties (unirradiated and Sections 7.1 and 7.2irradiated)

Young's modulus Section 6.6

2. Components other than Adherence to design-specificgrids component test protocol

Tensile properties (unirradiated and Sections 7.1 and 7.2irradiated)

_______________Young's modulus Section 6.6



4. Testing, Inspection, and Post-irradiation examination results Section 11.0Surveillance Plans to date and future plans

C. Post-irradiationSurveillance

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4.0 MATERIAL DEFINITION

The small differences in chemical composition between M5® and AREVA's new

structural alloy Q12 TM [

] This allows AREVA to utilize the extensive M5®

fuel performance experience base when designing structural components with the

QI2 TM alloy.

4.1 Material Composition

Q12 TM is a quaternary alloy, derived from the M5® alloy, and obtained by adding low tin

and iron contents. QI2TM retains a niobium content of 1 wt. % and has [

The chemical composition of QI2 TM is specified in Table 4-1. Impurity limits are defined

within the manufacturing material specifications and controlled by the manufacturing

processes.


Q12TM Structural MaterialTopical Report Pacqe 4-2

4.2 Micro stru cture

The Q12TM alloy is characterized by the presence of a monotectoid transformation at a

temperature close to 600003, analogous to the one for M5® (Reference 2). This

temperature is not significantly modified by adding small quantities of tin and iron. Tin, a

solid solution hardening element, has no major impact on the precipitate phases. By

adding iron and using a low-temperature heat treatment, the nature and proportion of

precipitate phases can be controlled. The use of a low-temperature process yields a

fully recrystallized structure [ ] a

uniform distribution of the precipitate phases that is favorable for corrosion behavior.

f3-Nb precipitates and Zr(Nb,Fe,Cr)2 hexagonal intermetallics (larger in number when

the iron content is high) with uniform distributions are observed. They exhibit similar size

distributions and average sizes for both QI2TM and M5c® alloys. Typical microstructures

for QI2 TM and M5® are shown in Figure 4-1 and Figure 4-2. The similarity is evident. In

addition, Kearns factors for Q12TM tubing were measured for eight lots. In Table 4-2, the

values are compared to the typical range for M5® tubing.

4.3 Manufacturing

Q12TM products (both tubing and sheet) are manufactured with the same process as for

equivalent M5® products.

Several thousand Q1 2TM alloy tubes have been manufactured to-date with various

geometries (cladding tubes, guide tubes, and test samples). Sheet for grids has also

been manufactured. For both forms, [

] The

thermomechanical processing steps for the production of tubing and sheet are shown in

Figure 4-3.

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Table 4-1 Chemical Composition of Q12TM Quaternary Alloy



Table 4-2 Kearns Factors for Q12TM and M5®

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Figure 4-1 Optical Microscopy of M5® and Q12 TM Microstructures

M5®17x17 Guide Tube

Q12TM17x17 Guide Tube


Q12 TM Structural MaterialTopical Report Pagqe 4-6

Figure 4-2 Distribution of Precipitates in M5® and Q12 TM

Microstructures

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Figure 4-3 Q12 TM Fabrication Process Outline


QI 2 TM Structural MaterialTopical Report Paaqe 5-1

5.0 IRRADIATION EXPERIENCE

[ ] fuel assemblies with Q12TM components have been irradiated

to-date in [ ] PWRs worldwide. This section describes that experience.

Multiple sets of lead assemblies with Q12 TM have been irradiated and discharged. Batch

reload quantities are currently undergoing first or second cycle irradiation. AREVA's

operating experience with Q12TM is extensive, and in-reactor performance results are

positive.

[ J fuel assemblies with Q12 TM cladding were inserted into [

](Table 5-1). The fuel has reached

assembly-average burnups up to [ J

Fuel assemblies with non-cladding Q12TM components were inserted into [

J fuel assemblies with Q12 TM guide tubes, or guide tubes and grids (but not

cladding) have been irradiated to date. The assemblies had arrays including [

J (Table 5-2). The fuel has reached assembly-average burnups up to

[ ] GWd/mtU.

Q12 TM cladding irradiation experience is summarized in Table 5-1 while Q12 TM guide

tube and grid irradiation experience is summarized in Table 5-2. Burnups reported in the

tables are the maximum for the 'set of assemblies under irradiation, or, if the burnup is

associated with an examination, the maximum for the assemblies that were examined.

In Table 5-2, "grids" refers to intermediate spacer grids.


Q12TM Structural MaterialTopical Renort P~-nt R~-?

Table 5-1 Summary of Q12TM Cladding Experience


Q12 TM Structural MaterialTopical Report Pa~qe 5-3

Table 5-2 Summary of QI2 TM Guide Tube and Grid Experience




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6.0 PHYSICAL PROPERTIES

This section provides values for the physical properties of Q12 TM . The first five

subsections discuss melting point, density, heat capacity, thermal expansion, and

thermal conductivity. Young's modulus and Poisson's ratio, sometimes classified as

mechanical properties, are discussed in the final two subsections. The physical

properties are used in various NRC approved methodologies to perform design

analyses of FA structural components.

6.1 Melting Point

The alloying elements in QI2TM have various effects on the melting temperature of

zirconium, with some capable of elevating the melting point and some depressing it at

high alloying concentrations. [

] variations within the

specification limits for Q12TM will not have a significant effect.

It is clear that melting of grids could compromise the coolability of a FA. As with

cladding, however, the temperatures required to melt Q12TM are well above those

required to embrittle the cladding, so no design analysis of melting is needed.

6.2 Density

The density of Q12 TM alloy has been measured by pycnometry and computed from

crystallographic data. Evaluation of the results gave a density of [ ] at room

temperatu re.

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Pane. R-2

In comparison, a density of [ "1 was reported for an alloy containing

significantly larger amounts of [ ] respectively).Because these comparatively large variations in composition do not have a significant

effect on the density, variations within the specification limits for Q12 TM will not have a

significant effect.

6.3 Heat Capacity

The results of theoretical calculations for the heat capacity of Q12TM were [

] variations within the specification limits for.

Q12 TM will not have a significant effect.

The heat capacity of Q12TM is represented by the following equations:

where Cp is the heat capacity (I .-• K-1 ) and T is the temperature (K).


QI2 TM Structural MaterialTopical Report Pacqe 6-3

6.4 Thermal Expansion

Coefficient of thermal expansion values in the axial direction are reported to range

between 5.2 x I10-4 and 6 x I104 % K-1 for various zirconium alloys including Zircaloy-2,

Zircaloy-4, and Zr-I1%Nb. These reported values demonstrate little dependence upon

the alloying element contents. Because the comparatively large variations in

composition between these alloys do not have a significant effect on thermal expansion,

variations within the specification limits for Q12TM will not have a significant effect.

Thermal expansion is dependent upon the manufacturing process. [

] the thermal

expansion of Q12 TM in the axial direction [

] is represented by the following equations:

-AL,.-

where - is the thermal expansion from 293 K to the temperature in question (%) and

T is the temperature (K).

6.5 Thermal Conductivity

The Wiedemann-Franz law states that the ratio between thermal conductivity and

electrical conductivity is proportional to temperature. This has been verified for different

zirconium alloys (Reference 3). Because the comparatively large variations in

composition between these alloys do not have a significant effect on thermal

conductivity, variations within the specification limits for Q12 TM will not have a significant

effect.

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P~an. R-4• -- i ... ... i ...... 11v v -

Electrical resistivity has been measured[

For Q12 TM without an oxide layer, the thermal conductivity is:

where A is the thermal conductivity (W. m-1 . K-') and T is the temperature (K).

I

The thermal conductivity of the oxide formed on Q12TM iS:

where A• is the thermal conductivity (W. m-' K-'), T is the temperature (K), and eox is

the oxide layer thickness (in).

6.6 Young's Modulus

Young's modulus was measured for Q12TM tubing undergoing cyclic loading and forQ12TM strip material samples extracted along three directions. The results from the

second and third loading cycles for the tubing tests and single cycle for the strip tests

are shown in Figure 6-1 and [

] Also shown in Figure 6-1 are upper and

lower design limits, [

] variations Within thespecification limits for Q12 TM will not have a significant effect.

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Q1 2 TM Structural MaterialTopical Report

Young's modulus for Q12TM is:PaQe 6-5

where E is Young's modulus (MPa) and T is temperature (00). The equation isapplicable to tubing tested in the axial direction and to sheet tested in any direction.

Values from the equation may be rounded to [ ] and []

6.7 Poisson's Ratio

Poisson's ratio is dependent upon the crystallographic state and texture of the material.

[

Poisson's ratio for Q12TM is:

C ]where v is Poisson's ratio.

] variations within the specification limits for Q1 2TM will not

have a significant effect.

AREVA Inc.

Q12TM Structural MaterialTop~ical Rep~ort

Figure 6-1 Young's Modulus Measurements and Model


Paqe 6-6



7.0 MECHANICAL BEHAVIOR OF Q12TM

7.1 Tensile Properties of Unirradiated Material

More than [ ] tensile tests have been performed on irradiated QI2TM tubes

(cladding, guide tubes, or instrument tubes) for development, qualification, and

certification at room or elevated temperatures [ ] The statistical

results for yield strength (YS), ultimate tensile strength (UTS), and total elongation (TE)

are summarized in Table 7-1, Table 7-2, and Table 7-3. The measured tensile

properties of M5®, taken from AREVA's acceptance database on cladding and guide

tubes (from 2002 to 2009) are provided for information and comparison. The Q12 TM

alloy demonstrates [

More than [ ] tensile tests have been conducted on Q12TM sheet material in the

unirradiated condition at room temperature Or [ ] (see Table 7-4 and

Table 7-5). Measurements were performed in both the longitudinal and transverse

direction. Values for M5® sheet at room temperature were determined from AREVA's

acceptance database on sheets (from 2006 to 2012) and are provided for information

and comparison. The tensile properties of Q12TM sheet [

] The temperature difference makes a direct comparison

difficult, but the data are in general agreement with trends seen at lower temperatures

and with tubing samples.

Overall, differences in tensile properties between Q12 TM and M5® [ ] and

the mechanical properties of Q12TM are enhanced by the tin and iron contents.


Q12TM Structural MaterialTopical Report Pagqe 7-2

The values reported in Table 7-1 and Table 7-4 represent the room temperature

measurements conducted to date. The [

] will be used for design analyses requiring the use of

bounding mechanical properties at room temperature.

7.2 Tensile Properties of Irradiated Material

Tensile properties of irradiated QI2TM material were assessed using tensile specimens

cut from defueled fuel rods irradiated in reactor D71 in Europe. These rods were

discharged at fuel rod average burnups of [ ] and [ ]

The mechanical properties obtained from these tests (YS, UTS, uniform plastic

elongation (UE), and TE) are shown in Table 7-6.

7.3 Fatigue Properties

Fatigue measurements were performed on irradiated [ IThe resulting number of cycles to failure is shown plotted against the alternating stress

in Figure 7-1. The irradiated fatigue behavior of [

] This graphical representation

accounts for a factor of 2 on stress, which was more conservative than a factor of 20 on

lifetime.

The chemistry and microstructure of Q12 TM (Section 4.0) are [

I

AREVA Inc.



Pacie 7-3

Table 7-1 Tensile Properties of Unirradiated Q12 TM and M5® Tubingat Room Temperature

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Q12 TM Structural MaterialTopical Report Paae 7-4

Table 7-2 Tensile Properties of Unirradiated Q12 TM and M5® Tubingat 3150 C


Q12 TM Structural MaterialTopical Report Pacqe 7-5

Table 7-3 Tensile Properties of Unirradiated Q12 TM and M5® Tubingat 400°C


Q12 TM Structural MaterialTnnicRJ R•.nnrt P~ini_ 7-R

Table 7-4 Tensile Properties of Unirradiated QI2 TM and M5® Sheet atRoom Temperature


Q12 TM Structural MaterialTopical Report Pa~qe 7-7

Table 7-5 Tensile Properties of Unirradiated Q12 TM and M5® Sheet at340°C

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Table 7-6 Tensile Properties of Irradiated Q12 TM Fuel Cladding atElevated Temperature

AREVA Inc.

QI2 TM Structural MaterialTopical Report


Paaqe 7-9

Figure 7-1 Fatigue Data and Model



8.0 OXIDATION AND HYDROGEN PICKUP

This section describes the oxidation and hydrogen pickup models for QI2 TM . The first

subsection presents the data on which the models are based. The remaining

subsections present the models for oxidation of guide tubes, oxidation of spacer grids,

and hydriding, respectively.

The buildup of crud is associated with the large heat flux at the surface of the fuel rods.

The heat fluxes are small at the surfaces of structural components, so crud buildup is

not a concern for Q12TM.

The Q12 TM oxidation and hydrogen pickup databases comprise the results of poolside

and hot cell examination results obtained on irradiated components from [

] Several types of components were used in the

derivation of the models, including cladding, spacer grids, and material test samples

(corrosion and creep samples). Exposure of Q12TM in different environments provides

confidence that oxidation and hydriding behavior are understood for all applications.

Figure 8-1 and Figure 8-2 provide an overview of the process that was used for

developing the oxidation and hydriding models.

Figure 8-1 shows that oxidation measurements were taken on the active length of fuel

rods with Q12TM cladding. Data from two reactors were combined and used to develop

a fuel cladding oxidation model. That model will not be used in fuel rod performance

predictions because Q12TM is not being used as a cladding material. Nevertheless, the

cladding model serves as the basis for the grid oxidation and guide tube oxidation

models. The functional form of the fuel cladding oxidation model was retained, but data

on grid oxidation were used to adjust the model. Similarly, oxidation data from fuel rod

plenums and from corrosion and creep samples were used to adjust the cladding

oxidation model for applicability to guide tubes.



The process for developing a model for hydriding was slightly simpler. As is shown in

Figure 8-2, an existing model for hydriding of fuel cladding was adapted to Q12 TM guide

tubes and grids. As with the oxidation model, the functional form of the existing model

was retained, but data from Q12TM components (fuel rod plenums, corrosion and creep

samples) were used to adjust the parameters of the model.

8.1 Basis of Q12TM Oxidation and Hydrogen Pickup Models

8.1.1 Fuel Cladding Oxidation

Data from QI2TM fuel rods were used as part of the basis for the Q12 TM guide tube and

spacer grid oxidation models. Poolside oxide thickness measurements were obtained

on Q12TM fuel rods irradiated in [

] The oxide

thicknesses were measured locally at several spans by the eddy current method without

removing the rods from the fuel assemblies.

8.1.2 Corrosion Sample in Reactor D24

A material test rod containing a Q12TM alloy corrosion sample was inserted into a guide

tube in reactor D24 in [ ] The sample was used to obtain information about

general oxidation and hydrogen pickup.

The material test rod was irradiated for five cycles; it was always located within guide

tubes of second cycle fuel assemblies and reached an exposure equivalent to a burnup

of approximately [ ] This burnup value is well beyond what is expected

for Q12TM FA components. Here and in Section 8.1.3, the term "burnup" is applied to

test samples that were irradiated in guide tubes; during each cycle the sample is said to

accumulate a burnup that is equal to the assembly-average burnup accumulated by the

host assembly.

After irradiation, the material test rod containing the Q12TM corrosion sample was

examined in a hot cell.

AREVA Inc.

Q12 TM Structural MaterialTonical Report


Paae 8-3- -r ....... r ..... •-- - -

] The oxide thicknesses were

[corrosion sample.

] Table 8-1 reports the average oxide thickness of the

The hydrogen content of the corrosion sample was also measured by hot vacuumextraction. The hydrogen measurements correspond to the oxide measurements [

] The hydrogen content values

are representative of two-sided corrosion.

At a burn up of approximately [of the corrosion sample is [

] the average measured oxide thickness] with a hydrogen content of

approximately [ ]

8.1.3 Creep Sample in Reactor 024

A Q12TM creep sample was inserted into reactor D24 and irradiated for five cycles,

reaching an equivalent burnup of approximately [ ] After the irradiation

the Q12TM creep sample was withdrawn for hot cell characterization.

Table 8-1 shows the average oxide thickness and the hydrogen content of the creep

sample. The sample was a sealed, pressurized tube, and therefore corrosion occurred

only on the outer surface. The hydrogen content of the creep sample was determined

by hot vacuum extraction.


Q12 TM Structural Material.Tnnical R•.nnrt Pane 8-4

At a burnup of approximately [of the creep sample is [

] the average measured oxide thickness

] with a hydrogen content of approximately

]

8.1.4 Fuel Rod Plenum Region Samples in Reactor D71

Two fuel rods with QI2TM cladding were removed from reactor D71 and sent to a hot

cell for characterization. The first rod was obtained after the second cycle and the

second rod after the fourth cycle. The fuel rod average burnups were [

] respectively. Table 8-1 shows the average oxide thickness and the

hydrogen content. Since the heat flux through the cladding of the plenum is small, the

oxidation behavior of the plenum is representative of guide tubes. The upper plenum

region also experiences the highest coolant temperature in the core. The oxide

thickness in the plenum region bounds that of the guide tubes, since the oxidation rate

increases with increasing temperature.

At a fuel rod average burn up of [thickness of the Q12 TM fuel rod plenum samples ih

] the average measured oxide

s [ ] with an average hydrogen

content of [ ] At a fuel rod average burnup of [ ] the

average measured oxide thickness is [ ] with a hydrogen content of [

8.1.5 Grid Oxide Measurements

Spacer grid oxide measurements were taken on four lead assemblies with intermediate

spacer grids made of alloy QI2TM. The grids of two lead assemblies were examined

after three cycles of irradiation in reactor D14, while the grids of the other two lead

assemblies were examined after two, three, and four cycles of irradiation in reactor 021.

Oxide thicknesses are plotted in Figure 8-4. The oxide thickness increases with

increasing elevation, as expected.


Q12TM Structural MaterialTopical Report Panqe 8-5

8.2 Q12TM Guide Tube Oxidation Model

The QI12TM fuel cladding oxidation model was developed on the basis of measurements

on fuel rods irradiated in two commercial plants.EThe Q12 TM fuel cladding oxidation model has the following Arrhenius expression:

]where erod is the oxide thickness for fuel cladding (pm), t is time (days), S is a kineticconstant (pm/day), Q is the activation energy (K), and Ti is the temperature of the metal-

oxide interface (K).

S is given by the equation:IMinimizing the square error between experimental results and predictions leads to:

[ ] A comparison of

I

predicted and measured cladding oxide thickness is shown in Figure 8-5.

The model for fuel cladding oxidation was adapted to guide tubes by fitting it to data

from the creep, corrosion, and fuel rod plenum samples. [

] the Q12 TM oxidation model for guide tubes is:L I

AREVA Inc.

Q12TM Structural MaterialTo~ical Renort

AN P-i0334NPRevision 0

Pane 8-6i - .-- r ..... 7-- -- --

where eGT is the best estimate for the oxide thickness on guide tubes. A comparisonbetween predicted and measured oxide thickness is shown in Figure 8-6. For added

conservatism and to avoid upnder-prediction, an upper design limit (UDL) model was

developed.

where eGT-UDL iS the upper design limit for the oxide thickness on guide tubes. ]I8.3 Spacer Grid Oxidation Model

The Q12 TM oxidation model for fuel cladding was modified as follows to fit the spacergrid measurements:Lwhere egrid is the thickness of oxide on a grid (p~m).

A comparison between the predicted and measured values is given in Figure 8-7. For

added conservatism and to avoid under-prediction, a UDL model was developed.

]I

8.4 Hydrogen Pickup Model

The cladding hydrogen pickup model has been adapted for use with Q12 TM guide tubesand grids.

The theoretical increase in hydrogen content due to two-sided corrosion (Hpickup) is:



where ez is the one-sided oxide thickness (p~m), HPUF is the hydrogen pickup fraction

[ ] ei is the initial thickness of the component (p~m), and HpIckup is in parts per

million (ppm).

To fit the observed hydrogen concentrations in the creep, corrosion, and fuel rod

plenum samples, [ ] and the Q12 TM

hydrogen pickup model is given as:

~where H0 is the initial hydrogen concentration. A comparison between predicted and]

measured hydrogen concentrations is given in Figure 8-8. For added conservatism, a

UDL model was developed and is applicable [ ]EJwhere Hm-UDL iS the UDL for hydrogen concentration.


Q12 TM Structural MaterialTonical Renort Paae 8-8

Table 8-1 Oxide Thickness and Hydrogen Content Measurementsfor Corrosion, Creep, and Plenum Samples


Q12TM Structural MaterialTopical Report Pinae R-9

Figure 8-1 Flowchart for Development of Q12 TM Oxidation Models


Q12TM Structural MaterialTopical Report Paoqe 8-10

Figure 8-2 Flowchart for Development of QI2 TM Hydriding Model



Figure 8-3 Geometry of Crevice Corrosion Sample


QI2 TM Structural MaterialTooical Reoort Paae 8-12

Figure 8-4 Q12 TM Spacer Grid Oxide Thickness Measurements afterTwo, Three, and Four Annual Cycles of Irradiation


Q12 TM Structural MaterialTo~ical Renort Pane 8-13

Figure 8-5 Comparison between Measurements and Predictions forthe Oxidation Model Developed for QI2 TM Cladding

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Figure 8-6 Comparison between Measurement and Prediction forthe Oxidation Model for Q12 TM Guide Tubes


Q1 2 TM Structural MaterialTonical Report Paae 8-15

Figure 8-7 Comparison between Measurement and Prediction forthe Oxidation Model Developed for Q12 TM Grids

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Q12 TM Structural MaterialTopical Report Pacie 8-16

Figure 8-8 Comparison between Measurement and Prediction forthe Hydrogen Pickup Model Developed for Q12 TM Guide Tubes and

Spacer Grids


Q12TM Structural MaterialTopical Report Pa~qe 9-1

9.0 FREE GROWTH AND CREEP

R&D irradiation programs on the Q12 TM zirconium alloy provide information on free

growth and irradiation creep, which are key attributes for guide tubes and spacer grids.

•In addition, substantial Q12 TM lead test assembly and initial batch implementation

programs in Europe provide important fuel assembly and spacer grid growth data.

These data collectively demonstrate the stability of the Q12TM alloy for structural

material applications for guide tubes, instrument tubes, and spacer grids.

Throughout Section 9.0, "fluence" refers to fast neutron fluence (energy > 1 MeV) in a

PWR. For tests in the test reactor BOR-60, fluences are converted to PWR fast neutron

fluences.

9.1 Q12TM Alloy Free Growth

Experimental irradiation campaigns to investigate the free growth of Q12TM were carried

out in a test reactor (BOR-60) and a commercial PWR (D24). The experimental

irradiation data show that Q12 TM alloy free growth is stable within the applicable range

of fluence. Free growth breakaway, which is typical of recrystallized zirconium alloys, is

observed, but the increase in growth rate occurs beyond the fluence range for PWR

fuel. Because of concerns that hydrogen would affect growth, pre-hydrided samples

were also tested. [

9.1.1 Irradiation in BOR-60

[ ] samples of Q12 TM tubing were irradiated in the BOR-60 fast

neutron reactor, which provides a sodium-cooled (non-corrosive) environment at 325°C.

Free growth versus equivalent PWR fast fluence is plotted in Figure 9-1. The fluences

for the BOR-60 reactor were converted to equivalent PWR fluences using the accepted

industry method (Reference 5).



As is commonly observed in recrystallized zirconium alloys, an initial rapid but small

growth occurs at low fluence. In a second regime, a plateau with a strain of about

[ ] is observed. Finally, an acceleration of the free growth occurs at high

fluence, [ ] beyond the fluence range for PWR fuel.

9.1.2 Irradiation in Reactor D24

Q12TM tubular test samples were placed inside the guide tubes of host fuel assemblies,

at high-flux elevations, in reactor D24. A schematic of the samples is shown in

Figure 9-2. The average temperatures were [

] The free growth samples are designed to allow water

flow inside and outside the test specimens, avoiding radial differential pressure and

allowing two-sided corrosion of the tubes. The irradiation conditions are therefore

representative of those of guide tubes.

Free growth versus fluence is shown in Figure 9-1. The trends are similar to those

observed in the BOR-60 irradiation, with an initial rapid growth followed by a plateau

and an acceleration at high fluence [ ]

9.1.3 Q12 TM Free Growth Model

The Q12TM free growth model is based on the combined data from the BOR-60 and D24

irradiations. [

] The maximum fluence for both programs

exceeds [ ] the fast fluence for PWR fuel assembly guide tubes at the

maximum licensed fuel rod burnup of 62 GWd/mtU (References 6, 7, and 8).


QI2 TM Structural MaterialTopical Report Pagqe 9-3

Free growth of Q12TM structural components is given by the following equations:Kwhere £zz is the axial free growth (%), 4 is the fast fluence (E+25 n/rn 2), [

Coefficients for the best-estimate, maximum, and minimum models are provided in

Table 9-1. All experimental free growth elongations are between the minimum and

maximum model predictions as shown in Figure 9-3.

9.1.4 Q1 2TM Free Growth - Hydrogen Effects

Hydrogen is known to induce earlier free growth breakaway in Zr-Il%Nb, Zircaloy-4, and

Zr-1%Nb-I%Sn-0.1%Fe alloys (Reference 8), so the impact of hydrogen on Q12 TM free

growth behavior was investigated. Samples of fresh QI2TM tubing were pre-charged

with hydrogen to [ ] and irradiated in the BOR-60 reactor.

For comparison, the maximum hydrogen concentration observed in a Q12TM test

sample in a PWR is [ ] (Table 8-1). Therefore, the concentrations used in the

BOR-60 tests envelope the expected value for QI2 TM guide tubes.

Figure 9-4 provides the free growth measurements for the pre-hydrided BOR-60

specimens. [

I


Q12 TM Structural MaterialTopical Report Panqe 9-4

9.2 Q12TM Alloy Creep

Creep experiments were carried out in parallel with the free growth experiments

described in Section 9.1. Samples of Q12 TM tubing were irradiated in reactors 024 and

BOR-60. The creep samples were also subject to growth, so the net strain due to creep

was obtained by subtracting the predicted strain due to free growth from the total strain

observed in the creep samples. Both compressive and tensile stresses were used, with

stress magnitudes comparable to those expected in guide tubes.

9.2.1 Irradiation in Reactor D24

As in the free growth tests, samples of QI2TM tubing were irradiated in commercial

reactor D24. [

] Positioned in a full-flux zone, the

creep samples were irradiated under conditions representative of guide tubes, with

temperatures ranging from [ ] cycles produced a maximum

fluence of [ ] which exceeds the maximum expected PWR fluence of

[ ]

A comparison between Q12TM and M5® creep behavior (after correction for free growth)

for a compressive stress of [ ] is shown in Figure 9-5. The results show that

Q12TM has [

] For the maximum expected PWR fuel assembly fluence of

[ ] the QI2 TM creep strain is approximately [ ]

The resistance of Q12TM to creep suggests that there will be less variation in fuel

assembly growth between different designs.



9.2.2 Irradiation in BOR-GO

Creep samples fabricated from fresh and hydrided Q12TM tubing were irradiated in the

BOR-60 fast neutron reactor, which provides a sodium-cooled environment at 32500.

The fresh samples were subjected to a tensile stress of [ ] The

hydrided sample had a hydrogen concentration of [ J and was subjected to

a tensile stress of [ J The irradiation program has achieved a maximum

fluence of [ ] which exceeds the expected maximum PWR fluence.

Figure 9-6 and Figure 9-7 provide comparisons of the Q12 TM and M5® creep behavior

for tensile stresses of [ I respectively. Results show that Q12 TM

has [ J For the maximum expected

PWR fluence of [ ] the Q12 TM creep strain is approximately [

]

To facilitate comparisons of creep tests at various stresses, the strains were normalized

(divided by the axial stress). Compressive stresses were treated as being negative, in

accordance with the common convention. The evolution of normalized creep strain

versus fluence is presented in Figure 9-8. [

]

AREVA Inc.

Q1 2 TM Structural MaterialTopical Report

9.2.3 Q12TM Creep Model

The Q12 TM creep model is:


Pagqe 9-6

Iwhere Ez is axial creep strain (%), az is axial stress (MPa), C•t is fluence (E+25 n/rn2),

T is temperature (K), Q is the apparent activation energy (5000 K), and [

It will be noted that the equation for creep strain [

-I

] A comparison between predicted and measured

strains is given in Figure 9-9. [

]

One of the specimens irradiated in BOR-60 was pre-hydrided. [

] An uncertainty of [ ] covers allresults for both fresh and pre-hydrided Q12 TM , up to the maximum expected PWR

fluence of [ ] as is shown in Figure 9-10.

AREVA inc.

Q12 TM Structural MaterialTooical Reoort


P•o 9-7,- -Table 9-1 Coefficients for Q12TM Free Growth Model


Q12TM Structural MaterialThnical Renort Paae 9-8

Figure 9-1 Free Growth versus Fluence - Comparison of Resultsfrom BOR-60 and D24



Figure 9-2 Schematic of Axial Creep and Free Growth Material TestRods


Q12TM Structural MaterialThnic2l Renort Pane 9-10

Figure 9-3 Free Growth versus Fluence: (a) Full Range of Data;(b) Detail for Fluences < 20 E+25 n/m2



Figure 9-4 Comparison of Q12 TM Free Growth for Fresh and Pre-Hydrided Specimens



Figure 9-5 Q12TM and M5® Creep - 024 Reactor Irradiation (10 MPaCornpress ion)


QI 2 TM Structural MaterialThoical Report Paae 9-13

Figure 9-6 Ql2 TMand M5® Creep - BOR-60 Irradiation (20 MPaTension)

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Q12 TM Structural MaterialTopical Report Page 9-14

Figure 9-7 Q12 TM and M5® Creep - BOR-60 Irradiation (40 MPaTension)



Figure 9-8 QI2 TM Normalized Creep ,Strain - BOR-60 and 024Reactor Irradiation


Q12TM Structural MaterialTopical Report Paaqe 9-16

Figure 9-9 Comparison of QI2 TM Axial Creep Predictions andExperimental Results


QI2TM Structural MaterialTopical Report Pacqe 9-17

Figure 9-10 Comparison between Q12TM Axial Creep Predictionsand Experimental Results


Q12TM Structural Material_Topical Report Paqe 10-1

10.0 GROWTH CORRELATIONS

Growth correlations have been developed for FAs containing Q12TM guide tubes as well

as for Q12TM spacer grids. The FA growth correlation considers the irradiation

experience of lead assemblies containing Q12TM structural components while the grid-

growth correlation considers the irradiation experience of Q12TM spacer grids [

] The correlations are presented here along with the

methodologies utilized for their development.

10.1 Fuel Assembly Growth Correlation

The Q12TM fuel assembly growth correlation is based on axial growth data for

assemblies with Q12TM guide tubes. Lead assembly programs have been completed or

are underway in [ J reactors, and Q12 TM fuel assemblies have been

implemented in [" ] reactors. C ]

assemblies with Q12 TM guide tubes have been irradiated to-date. Table 5-1 and Table

5-2 present a summary of the QI2TM lead programs and batch implementation and the

associated reactors and fuel design lattices, with further detail provided in Section 5.0.

Figure 10-1 provides the Q12 TM fuel assembly growth design limits and corresponding

data, which total [ J measurements. Measurements have been taken

[


Q12TM Structural MaterialTopical Report Paqie 10-2

The upper and lower design limits (UDL and LOL) are conservatively developed [

10.2 Q12TM Spacer Grid Growth Correlation

The QI2TM spacer grid growth correlation is based on grid lateral envelope

measurements [ ] The correlation is

shown in [

]A total of [

] compose the collective grid growth data set. The data

for [ ] represent [

I and [ ].

The Q12 TM grid growth data are from the [ ] grid designs.



Grid growth for zirconium alloys varies by elevation and is attributed to the grid material

free growth, creep, and corrosion behavior. The highest grid growth typically occurs in

the upper half of the fuel assembly. The Q12TM grids are found to have growth behavior

]A

95/95 one-sided upper tolerance limit is calculated using the collective maximum grid

data set. The tolerance limit is used as the Q12TM grid growth upper design limit.


Q12 TM Structural MaterialTopical Report Paq~e 10-4

Figure 10-1 Q12TM Fuel Assembly Growth Data and Design Limits


Q 1 2 TM Structural MaterialTopical Report Paqe 10-5

Figure 10-2 Upper Design Limit for Q12TM Grid Growth Using M5®and Q12 TM Grid Growth Data

AREVA Inc.

Q12TM Structural MaterialTonical Renort


Paae 11-I

11.0 SURVEILLANCE

The following sections present the near term AREVA plans for FA examinations.

Although AREVA regularly plans post-irradiation examinations (PIEs) several years in

advance, the plans are subject to change.

11.1 U.S. Surveillance

] Of the inspections

listed in Table 11-1, the FA length, FA bow, and guide tube oxide measurements

provide information on the performance of Q12TM [

] Other inspections are mentioned for information

only.

J Of the inspections listed in Table 11-2, the FA

length and FA bow measurements provide information on the performance of Q12TM.

Other inspections are mentioned for information only.

11.2 European Surveillance

Surveillance of lead assemblies and batch fuel continues in Europe. Table 11-3 outlines

the recommended PIE scope for European lead assemblies in 2015. In future years

(2016, 2017) a continuation of the 2015 surveillance program is planned.


Q12 TM Structural MaterialTopical Report Paq~e 11-2

Table 11-1 PIE Plan for Lead Assemblies in Reactor B42

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Table 11-2 PIE Plan for Lead Assemblies in Reactor B40


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Table 11-3 PIE Plan for European Lead Assemblies in 2015


Q12 TM Structural MaterialTopical Report Paqie 12-1

12.0 UPDATE PROCESS

AREVA plans to continue to monitor the performance of Q12 TM in lead assemblies and

batch fuel, both in the U.S. and in Europe. Through various material test programs

AREVA also plans to continue to gather in-core, out-of-core, and test reactor data on

Q12TM. As data are obtained for more burnups and for an increasing number of fuel

designs, the models presented in this report may require adjustment. These activities

allow AREVA to continuously expand its knowledge and improve its predictive

performance tools for Q12TM.

As Q12 TM data are obtained the AREVA PIE database will be expanded. Periodically,

the models discussed in Sections 6.0 to 9.0 will be reviewed against the growing

database. If the data support a modification to any of the Q12TM models used for design

analyses, the internal AREVA design change process will be followed. This change

process includes documentation and justification of the change and evaluation of the

impact on future design analyses. Any changes to the models presented in Sections 6.0

to 9.0 will be maintained in an internal AREVA document. Changes to the models in

Section 10.0 are discussed in Sections 12.1 and 12.2.

12.1 Fuel Assembly Growth Model

Because of the importance of fuel assembly growth, it is appropriate to impose

additional criteria for changing the design limits for growth. The [ ]

UDL for the growth of FAs with Q12TM guide tubes, presented in Section 10.1, provides

a significant margin to the current database of FA growth measurements. [

]


Q12TM Structural MaterialTopical Report Paqe 12-2

The following criteria will be used to determine when the UDL and LDL can be modified.

AREVA's experience shows [

J the UDL and

LDL presented may be adjusted. [ ]may

be defined through this update process for any design[

] Any reduced design

limits established through this update process will be required to adhere to the

prescribed data conditions.

12.2 Spacer Grid Growth Model

The following criteria will be used to determine when a [

] AREVA's experience shows the spacer grid growth increases with fuel

assembly burnup. Once AREVA has collected [

] Each measurement will

represent the maximum growth for a single fuel assembly at a given burnup. [

12.3 NRC Notification

A summary of any updates made to the models will be provided to the NRC in a letter

report for information.



The update process ensures that design margins are maintained, and it examines the

updates with regard to the limitations specified in the NRC's Safety Evaluation Report. If

the updates are outside of the NRC's Safety Evaluation Report limitations, then one of

the following actions will be taken:

1. No credit taken for the update

2. Update documented for NRC review and approval

3. Update included in a License Amendment Request for site-specific approval


Q12TM Structural MaterialTopical Report Paqe 13-1

13.0 ,REFERENCES

1. Standard Review Plan, NUREG-0800, Chapter 4, U.S. Nuclear Regulatory

Commission, March 2007.

2. V. Chabretou, et. al, Ultra Low Tin Quaternary Alloys PWR Performance -

Impact of Tin Content on Corrosion Resistance, Irradiation Growth, and

Mechanical Properties, Journal of ASTM International, V/ol.8, No. 5, Paper

ID JAI103013.

3. R.W. Powell and R.P. Tye, "The thermal and electrical conductivities of

zirconium and of some zirconium alloys," Journal of The Less Common

Metals, Vol. 3, 1961, pp. 202-21 5.

4. W.J. O'Donnell and B.F. Langer, "Fatigue Design Basis for Zircaloy

Components," Nuclear Science and Engineering, Vol. 20, 1964, pp. 1-12.

5. EPRI Report 1019098, The NFIR-V Dimensional Stability Project-A

Method for Transposing Test Reactor Irradiation Data for PWR and BWR

Applications.

6. BAW-10227P-A, Rev. 1, Evaluation of Advanced Cladding and Structural

Material (M5®) in PWR Reactor Fuel.

7. BAW-10186P-A, Rev. 2, EXTENDED BURNUP EVALUATION.

8. BAW-1 0240P-A, Rev. 0, Incorporation of MSTM Properties in Framatome

ANP Approved Methods.

9. EPRI Report 1021035, The NFIR-V dimensional stability project - BOR-60

irradiation and growth data.

Documents

ANP-10334NP, Revision 0, 'Q12 Structural Material, Topical ... · AREVA Inc. ANP-1 0334NP Revision 0 Q12TM Structural Material Topical Report Paqe 1-1 1.0 INTRODUCTION AREVA has developed