Research has been published over the past few decades on the possible use of thorium in various nuclear power reactor types. Therefore, it is worthwhile to analyse the supply situation for additional thorium generated as a by-product of commodities produced for non-nuclear purposes. This publication provides information on the natural occurrence of thorium, the geology of thorium and potential thorium resources. It presents an overview of exploration and evaluation of projects, including studies for project feasibility, principles of ore processing, as well as market and production scenarios. Selected examples of deposits containing thorium as a potential co-product or by-product are presented as case studies.

Seismic isolation technology has the potential to significantly reduce the overall risk to nuclear power plants posed by earthquake ground motions. A testing programme is an integral part of a seismic isolation project. Not only do the isolating devices need to be characterized for design purposes, but the analytical procedures used in design need to be validating. Hybrid simulation is a testing technique which is a good candidate to experimentally assess the behaviour of an isolation system. The method combines the computation of the response of the isolated structure with the experimental determination of the behaviour of full-scale isolators under the demand imposed by the movement of ground and structure. This publication contributes to the assessment of the method as a tool for the design and safety demonstration of base-isolated nuclear facility buildings.

This publication summarizes the findings and conclusions of an IAEA coordinated research project on fuel modelling in accident conditions, which was initiated under the IAEA Action Plan on Nuclear Safety following the Fukushima Daiichi accident. The overall aim of the project was to analyse and better understand fuel behaviour 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 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 coordinated research project provided an ideal platform for participants to compare their code results with other results and especially with experimental data, to which they otherwise would not have had access.

The IAEA organizes international collaborative standard problems (ICSPs) to facilitate the development and validation of computer codes for design and safety analysis of nuclear power plants, which usually includes an experimental investigation of important phenomena and simulation of the experiment with computer codes. This ICSP investigated phenomena that determine the thermomechanical behaviour of heavy water reactor fuel channels during a fuel overheating scenario. The publication summarizes the experiment, the complex and transient nature of phenomena interactions that ultimately determine fuel channel behaviour, the simulation methods and results, and the lessons learned from the ICSP. It provides a comparison of the results obtained from eight participating organizations from five countries, utilizing different methods and computer codes. General conclusions drawn and recommendations made for future developments are also included.

As nuclear power is one of the options that can be used to meet the growing energy demands of countries around the world, educating and enriching people with adequate knowledge on nuclear energy, nuclear reactor technologies, nuclear systems, reactor components and the embedded nuclear safety features are of paramount importance. Experience shows that education and training nuclear power plant simulators are effective tools that allow for a broad range of target groups to meet education and training objectives. This publication provides information based on the lessons learned from IAEA training courses on reactor technologies with the use of various NPP simulators. The main topics are classification of various types of NPP simulators for education and training, suitable selection of simulators according to assessment of education and training needs, and integration of simulators into educational and training programmes to enhance knowledge based skills.

This publication provides technical and scientific information regarding the radiation monitoring, radio-ecological research and management of the Chernobyl nuclear power plant cooling pond. It focuses on the assessment of the environmental and radiological conditions after the pond drawdown, as a basis for justification of the decommissioning and remediation strategy for the pond. Special attention is paid to the analyses of remedial actions to reduce ongoing or potential doses to members of the public and plant staff due to radiological impacts resulting from the drawdown of water level in the pond. The publication also outlines practical experience gained throughout the cooling pond decommissioning project, which started in 2014 and continues into the present. It presents data from a monitoring programme, comparing modelling predictions of the dynamics of the cooling pond drainage and related radiological and ecological impacts, with the consequences of the drawdown of the water level in the cooling pond that were actually observed. Additionally, the publication summarizes lessons learned and addresses outstanding issues.

This publication is intended to assist the management teams of operating organizations and nuclear power plants (NPPs) that outsource certain activities or use external services, in identifying and implementing an appropriate knowledge management strategy. A proactive approach to acquiring new organizational knowledge and the competence needed for operating NPPs is described. The methodologies provided are applicable to outsourcing for all phases of the nuclear power plant life cycle including preparation, design, construction, operation, long term operation and decommissioning. While this publication applies primarily to NPPs and focuses on operating plant processes, it also may be relevant for other nuclear organizations, such as research facilities, technical support organizations, academic facilities and nuclear fuel cycle facilities.

With more than 170 parties having ratified the Paris Agreement under the United Nations Framework Convention on Climate Change, viable, financially sound and integrated solutions for providing low carbon, affordable energy is of critical interest. This, by necessity, encompasses the development of resilient production processes for the generation of electricity, heat, chemicals and fuels for deep decarbonization. Two principal options for low carbon energy are renewables and nuclear energy. While many institutions have expressed interest in one or the other of these options, few have explored the possible synergies between them. This publication consists of the proceedings of an IAEA Technical Meeting held to review and discuss concepts and innovative solutions, including the advantages and challenges associated with each option, pertaining to nuclear–renewable hybrid energy systems for decarbonized energy production and cogeneration.

This publication addresses the different components in which any well trained nuclear medicine physician must be competent. It stresses the importance of providing support for the implementation of the prescribed programme, thus meeting the individual needs of trainees. Likewise, it emphasizes the appropriate duration of training necessary to acquire the competencies needed to provide adequate care to patients and ensure the safety and quality of clinical practice. Moreover, the principles and practice of physics, radiochemistry, anatomy, physiology and clinical nuclear medicine, including hybrid imaging are discussed.

This publication presents the results of the impact evaluation of one of the IAEA's flagship courses in radiation safety, the postgraduate educational course in radiation protection and the safety of radiation sources (PGEC). This course is hosted in the IAEA regional training centres. The impact evaluation covers a period of 35 years, surveying the PGEC participants from past courses taking place since 1981: this represents a rather unique case of a systematic evaluation of a training programme. The publication provides an overview of the PGEC impact on participants' professional development and career, and on the radiation safety infrastructure at organizational and national levels. Overall results of the impact evaluation are presented at regional level (Africa, Asia and the Pacific, Europe, and Latin America and the Caribbean), as well as globally.

This publication is intended to support the proper use of the compound specific stable isotope (CSSI) technique for identifying sources of sediment within agroecosystems. Based on the measurement of carbon-13 natural abundance signatures of fatty acids in the soil, this technique allows users to determine and apportion the sources that originate from different land uses. While covering the fundamental concepts of the CSSI technique, this publication is unique in providing step-by-step instructions for scientists, technicians and students on how to effectively use this isotope approach. This comprehensive illustrated guide highlights new opportunities for improving area-wide soil conservation strategies in fragile agricultural landscapes.

This publication presents the results of an IAEA coordinated research project (CRP). The benchmark analysis performed under this CRP covered steady state and transient conditions for research reactors across a range of designs, power levels, operating regimes and experimental facilities. The results obtained by the individual CRP participants are consolidated for each benchmark specification and conclusions are drawn on the specifications, modelling approaches and user effects, and computer codes used in the analysis. This publication supplements IAEA Technical Report Series No. 480, Research Reactor Benchmarking Database: Facility Specification and Experimental Data, which was developed within the same CRP. The publication is intended for use by operating organizations, researchers, regulatory bodies, designers and other interested parties involved in the safety, operation and utilization of research reactors. The individual country reports are available on the attached CD-ROM.