Assessment Of Post Irradiation Examination Techniques For Advanced Reactor Fuel And Materials

This publication has been developed based on the results of the Technical Meeting on Advances in Post-Irradiation Examination Techniques for Power-Reactor Irradiated Fuels and Innovative Fuels held in July 2021. It explores the use of existing and new post-irradiation examination (PIE) techniques for the study of next-generation fuel types. Specifically, this publication provides an overall understanding of what important performance parameters are typically studied for each fuel type to properly assess its performance, and what are the relevant PIE techniques required for the analyses. Its intended audience comprises nuclear fuel designers, manufacturers, operators, regulators, academia and policy makers who work with the nuclear fuel community

Post-irradiation examination (PIE) is an indispensable step in the selection of new or improved research reactor fuel, and in the characterization and understanding of its in-core behaviour. This publication provides an introduction to PIE techniques. It describes a typical PIE process from intercycle inspections in the reactor pool or channel, to hot cell PIE, which is subdivided into non-destructive and destructive testing techniques with their typical output, advantages and drawbacks, and their applicability to understanding fuel irradiation behaviour. Much of the work presented in this publication originated from the research and development of new low enriched uranium research reactor fuels. Intended readers include research reactor operators, regulators and their technical support organizations, fuel developers and manufacturers, laboratory staff, and policy makers.

There is high interest in new fuel types with increased accident tolerance. These range from using an oxidation resistant coating on zirconium based cladding to alternate fuel and cladding materials. These new fuels/claddings under development must be licensed before being deployed industrially and therefore research is being undertaken to assess their behaviour in various conditions. This publication arises from an IAEA coordinated research project (CRP) dealing with the acquisition of data through experiments on new fuel types and cladding materials and the development of modelling capacity to predict the behaviour of the components and the integral performance of accident tolerant fuel designs under normal and transient conditions. Demonstrations of improvements under severe accident conditions were documented. Several coated cladding materials were produced, tested, characterized and analysed in round robin tests carried out within the CRP. For improvement and validation of fuel performance codes, several benchmarks were organized to compare and analyse predictions of the extended codes. The findings and conclusions of the CRP are summarized in this publication.

This publication summarizes the findings and conclusions of an IAEA coordinated research project (CRP) on fuel modelling in accident conditions, which was initiated under the IAEA Action Plan on Nuclear Safety following the Fukushima accident. The overall aim of the project was to analyse and better understand fuel behavior in accident conditions, with a focus on loss of coolant accidents. In the course of the project the participants used a mixture of data derived from accident simulation experiments, in particular data designed to investigate the fuel behaviour during design basis accident and design extension conditions. They carried out calculations on priority cases selected from a matrix of cases identified at the first research coordination meeting and designed to support their individual priorities. These priority cases were chosen as the best available to help determine which of the many models used in the codes best reflect reality. The CRP provided an ideal platform to compare their code results with others and especially with experimental data, to which they otherwise would not have had access. The achievements made within this CRP fostered new collaborations and enhanced the development and improvement of common models and highlighted differences in the interpretation of some experiments and therefore in the use of the codes ? the so-called user effects.

To facilitate the deployment of innovative nuclear systems, different aspects of the infrastructure, technical as well as institutional, are reviewed, and recommendations for changes are made to anticipate the main developments worldwide, such as ongoing globalization.

"This publication presents the proceedings of a technical meeting on research reactor application for materials under high neutron fluence. The overall objective of the meeting was to enhance research reactor utilization in Member States for practical applications such as isotope production, neutron radiography, neutron beam research, and material characterization and testing consistent with the reactor's research function. In addition, the meeting participants focused on the specific applications of research reactors in irradiation of materials at high neutron fluence, as well as integration issues. The publication will serve as a tool to maintain existing knowledge available in Member States and is expected to contribute to the initiation and development of new research programmes related to the testing of structural materials needed for innovative reactor systems"--Publisher's description.

The limitation of 235U enrichment is a current concern among IAEA Member States. In response, work has been undertaken to provide a platform to facilitate a comprehensive review of the current status, prospects and challenges associated with the use of fuels having enrichments higher than 5 % 235U in light water reactors. This publication is the outcome of two technical meetings and compiles the results and conclusions in terms of benefits to be obtained from the use of high assay low enriched uranium (HALEU) fuel, with due consideration of safety issues that arise from its use. It details technological options and corresponding issues regarding fuel and core design, safety analysis and assessments relevant to manufacturing, handling, transportation, storage, irradiation, and performance in normal and accident conditions.

Industrial growth, energy consumption are seen as measures towards economic developments. With increase in industrial development worldwide, the demand of energy is continually on the rise. Today, the energy industry is facing many challenges. Nuclear fission and nuclear fusion are seen as important future energy sources. Development of innovative reactor designs with large efficiency for fuel burn up is one of the needs of fission reactors. The materials resistant to high dose of radiations in fusion reactors is another major challenge. The production of electricity without global warming is an important pressing demand on the energy sector. The demands on quality control of components for nuclear and heavy industry are very stringent. Development of well characterized, high quality materials is therefore essential for safe, efficient and reliable operation of engineering components. The diagnosis of failure of machinery parts comes from the post operational characterization of materials. Various destructive and non-destructive techniques are used for this purpose. Research reactors have played an important role in non-destructive characterization of materials and have contributed to technology development. This publication focuses on characterization of materials for industries in general and nuclear energy sector in particular. The main focus is on research reactor based techniques with some discussion on other allied methods like positron annihilation.--Publisher's description.