基本説明
Can help to prevent the most severe nuclear accidents (heating of nuclear fuel so that its pressure reaches explosive values).
Full Description
In the beginning of the 1990's, in the course of the events which were rapidly cha- ing the political con?guration of the East European countries, the crisis which - vested the vast research apparatus of the former Soviet Union was entailing con- quences whose dimension and depth were immediately realized by the international scienti?c community. In the same years, however, the most important branch of nuclear energy - searchanddevelopment,inparticularthatconcerning?ssionreactor,wasworldwide undergoing a substantial reduction due to a variety of decisional situations. Yet, paradoxically, it was a very good fortune that a number of concerns on the future of nuclear research were shared by East- and West-European scientists, especially those who were working in advanced ?elds. In fact, the only hope for coping with an uncertain future was to erect bridges between similar institutions and employ safeguarding tactics linked to a long term collaboration strategy. A decade later, this proved to be a winning decision, since the revival of nuclear energy is presently starting from a basis of common intentions and a network of established cooperation, whose seeds are to be searched in those initial, individual e?orts.
Contents
1 Introduction.- 1.1 Reactor Accident Analysis and Fuel Equation of State.- 1.2 The Role of Equation of State.- 1.3 Equation of State for Liquid UO2: Historical.- 1.4 Summary of the New Equation of State Features.- 1.5 General Notations.- 2 Governing Equations and Fundamental Formulae.- 2.1 Introduction.- 2.2 The Concept of Equation-of-State.- 2.3 Model Equations of State.- 2.4 Physical and Chemical Models in Thermodynamics of Reacting Fluids.- 2.5 Conclusions.- 3 Ionic Models for Liquid Urania.- 3.1 Restricted Primitive Ionic Model.- 3.2 Extended Ionic Model.- 3.3 Local Equations of State for the Liquid Phase: General Requirements.- 3.4 Improved Restricted Primitive Ionic Model.- 3.5 Compatibility Conditions.- 3.6 Determination of the Coulomb Contribution.- 3.7 Conclusions.- 4 Gas-Liquid Coexistence in Uranium Dioxide.- 4.1 General Conditions of the Phase Equilibrium.- 4.2 Calculation of the Equilibrium Composition and Thermodynamic Functions.- 4.3 General Structure of the Liquid-Vapour Phase Boundaries in UO2±x.- 4.4 Equilibrium Properties and Composition of UO2±x.- 5 Application of the Chemical Model within the van der Waals Approximation.- 5.1 Non-Congruent Evaporation over UO2±x.- 5.2 Oxygen Potential.- 5.3 Composition of the Liquid Phase.- 5.4 Discussion.- 5.5 Justification of the MIX Models.- 6 New Equation of State for Fluid Uranium Dioxide Based on Thermodynamic Perturbation Theory.- 6.1 Thermodynamic Perturbation Theory.- 6.2 Fluids Composed of Molecules with Anisotropic Interaction.- 6.3 Conclusions.- 7 Thermodynamic Properties of UO2, as Predicted by the New Equation of State.- 7.1 Summary of the Model Features.- 7.2 Calibration.- 7.3 Validation of the INTAS-99-EOS.- 7.4 Non-Congruent Equilibrium and Critical Point.- 7.5 Concluding Remarks.- A Appendix.-A.1.2 Volume Changes on Melting.- A.1.3 Thermal Expansion.- A.1.4 Elastic Properties and Adiabatic Compressibility.- A.1.6 Enthalpy and Entropy of Fusion.- A.1.8 The Congruently Vaporising Compositions of Urania.- A.2 Individual Components. Tables of Thermodynamic Functions.- A.3 Estimated Molecular and Ionic Interaction Constants.- A.3.1 Polarisability of Atomic O and U.- A.3.3 Dispersion Constants.- A.3.6 Conclusions.- A.4 Thermodynamic Tables.- References.
