Nuclear Materials Under Irradiation

Serge Bouffard is a retired Research Director for the CEA and has devoted his career to the study of the interaction of particles with materials and the mechanisms of defect creation. He is the man behind EMIR: the French national network of accelerators for the study of materials under irradiation.Nathalie Moncoffre is a Research Director at the CNRS, specializing in the aging of nuclear materials. In particular, she has studied the behavior of fuel, metallic alloys, absorbers and graphite under irradiation. She is the manager at the EMIR&A: the French national network of accelerators for irradiation and analysis of molecules and materials.

• Preface xiSerge Bouffard and Nathalie MoncoffreChapter 1 Irradiation Defects 1Serge Bouffard and David Siméone1.1 Introduction 11.2 Some basic data 21.2.1 Radiative environments and nuclear materials 21.2.2 Some notions about the transport of particles in matter 51.2.3 The zoology of irradiation defects 91.3 Defect creation mechanisms 111.3.1 Creation of defects by elastic collisions 131.3.2 Amorphization 161.3.3 Creation of defects by electronic excitation 181.3.4 Synergy between elastic collisions and electronic excitations 261.4 Kinetics of defect evolution 281.4.1 Mean field approach: reaction rate theory 291.4.2 Evolution of extended defects: kinetics of clusters in the mean field 331.4.3 Kinetic Monte Carlo approach 341.4.4 Phase field approach 361.5 Open-ended problems 381.6 Acknowledgements 401.7 References 40Chapter 2 Metal Alloys 47Philippe Pareige and Christophe Domain2.1 Introduction 472.2 Fuel cladding 522.2.1 Growth and creep under irradiation 542.2.2 Stress corrosion cracking 562.2.3 The mechanisms of the evolution of the properties under irradiation 572.2.4 Simulations of growth and creep under irradiation 582.3 Internal structures in austenitic steel 592.3.1 An effect of irradiation: intergranular segregation 612.3.2 Evolution of mechanical properties under irradiation 642.3.3 Creep under irradiation 652.3.4 Swelling 662.3.5 Irradiation-assisted stress corrosion cracking 672.4 The vessel 692.4.1 Changes in tenacity and resilience 702.4.2 Cluster dynamics 722.5 Perspectives 772.6 References 80Chapter 3 Ceramics within PWRs 87Christine Delafoy, Frederico Garrido and Yves Pipon3.1 Introduction 873.2 Development and typical properties of UO2 and B4C ceramics 913.2.1 Development and structure of uranium dioxide 913.2.2 Development and structure of boron carbide 933.2.3 Thermomechanical characteristics of B4C and UO2 963.3 Aging of ceramics under irradiation 1003.3.1 Evolution of the properties of uranium dioxide under irradiation 1013.3.2 Evolution of boron carbide properties under irradiation 1123.4 Future challenges 1163.5 References 120Chapter 4 Nuclear Graphite 125Nicolas Bérerd and Laurent Petit4.1 What is nuclear graphite? 1254.2 Why use graphite in nuclear reactors? 1284.3 Evolution of nuclear graphite in reactors 1294.3.1 Neutron irradiation 1304.3.2 Irradiation defects in nuclear graphite 1334.3.3 Evolution of lattice parameters and crystallite size in irradiated graphite 1394.3.4 Density and porosity evolution by radiolytic corrosion of graphite 1414.3.5 What are the consequences at the macroscopic scale? 1424.4 Conclusion 1434.5 Acknowledgements 1444.6 References 145Chapter 5 Nuclear Glasses 151Magaly Tribet5.1 Glass of nuclear interest: their role and their aging conditions under irradiation 1515.1.1 What is this kind of glass for? 1515.1.2 What does this glass actually contain and in what form? 1525.1.3 Nuclear glass radioactivity 1545.1.4 A complex scenario of glass aging under deep geological conditions 1575.2. How are the effects of long-term irradiation studied at the laboratory scale? 1585.3 Closed system: evolution of glass subjected to its self-irradiation and to the accumulation of helium 1615.3.1 Impact of βγ irradiation 1615.3.2 Effects of α decays 1635.3.3 Accumulation of helium 1655.3.4 Summary of knowledge in closed system 1665.4 Open system: alteration of glass by water under irradiation 1675.4.1 General information on the behavior of glass under water – methodology 1675.4.2 Taking irradiation into account in this multi-phase system 1705.4.3 Irradiation and initial alteration rate 1705.4.4 Irradiation and residual alteration rate 1725.4.5 Summary on the behavior of glass under water and under irradiation 1745.5 Summary and prospects 1755.6 Acknowledgements 1765.7 References 176Chapter 6 Radiolysis of Porous Materials and Radiolysis at Interfaces 181Sophie Le Caër and Jean-Philippe Renault6.1 Introduction 1816.2 General information on radiolysis 1826.2.1 A few definitions 1826.2.2 Radiolysis of liquid water 1836.3 Main porous materials of interest 1856.4 Dosimetry in heterogeneous media 1866.5 Production of dihydrogen by radiolysis of water in a confined medium 1876.5.1 Methods for calculating the yield of dihydrogen production 1876.5.2 Reaction mechanisms 1896.5.3 Different parameters influencing the production of dihydrogen under irradiation 1906.6 Understanding transient phenomena 1916.6.1 Study of a short-lived species, the hydroxyl radical 1916.6.2 Confinement effect on the reactions taking place and their rate constants 1936.7 Conclusion: what about the effects of radiolytic species on materials? 1966.8 References 197Chapter 7 Concrete and Cement Materials under Irradiation 201Pascal Bouniol7.1 Introduction 2017.2 Radiation shielding concrete 2027.2.1 Overview 2027.2.2 Effects of irradiation on the cement matrix 2037.2.3 Effects of irradiation on aggregates 2047.2.4 Prediction of concrete damage 2067.3 Waste conditioning matrices 2077.3.1 Overview 2077.3.2 Radiolysis of the cement matrix 2077.3.3 Phenomenological couplings 2107.4 Conclusion 2117.5 References 212Chapter 8 Organic Materials 215Emmanuel Balanzat and Muriel Ferry8.1 Introduction 2158.2 Technological context 2178.2.1 Organic materials of the nuclear industry 2178.2.2 Polymers in the reactor building 2208.2.3 Nuclear waste 2228.3 Radiation exposure 2248.3.1 The LET effect 2248.3.2 β/γ irradiation 2258.3.3 α irradiation 2258.3.4 Thermal neutrons 2278.3.5 Other projectiles 2278.4 Irradiated polymers: phenomenology 2288.4.1 Resistance of polymers to irradiation 2288.4.2 Changes induced by irradiation 2308.5 Radiolysis in anoxic polymers: fundamental effects 2318.5.1 Polymer radiolysis: introduction 2318.5.2 A textbook case: polyethylene 2338.6 The radio-oxidation of polymers 2368.6.1 Mechanism of radio-oxidation 2368.6.2 Chemical and physical influences of the dose rate 2398.6.3 α irradiation 2418.7 Conclusion and perspectives 2438.8 References 243Chapter 9 Irradiation Tools 251Serge Bouffard and Nathalie Moncoffre9.1 Why experiment with accelerators? 2519.2 Irradiation conditions in nuclear energy 2529.2.1 Characteristics of these particles 2529.2.2 How is irradiation simulated in a nuclear environment? 2539.3 Tools for simulation 2569.3.1 Research reactors 2569.3.2 Accelerators 2589.3.3 Use of radioactive elements 2649.4 Some major irradiation research centers 2649.5 Conclusion 2679.6 References 267Chapter 10 Characterization of Irradiation Damage 269Aurélie Gentils, Stéphanie Jublot-Leclerc and Patrick Simon10.1 Introduction 26910.2 Characterization of point defects 27010.2.1 Positron annihilation spectroscopy 27010.2.2 Raman scattering 27110.2.3 Other techniques 27410.3 Characterization of the global disorder and elastic strain 27510.3.1 Raman spectroscopy 27510.3.2 Ion beam analysis 27710.3.3 X-ray diffraction 28010.4 Imaging of extended defects and cavities 28210.5 Elemental analysis 28410.6 In situ microstructural characterization of materials subjected to irradiation 28610.7 Conclusion and perspectives 28810.8 References 289List of Authors 293Index 295