Neutron activation analysis (NAA) is the technique most widely used in research reactors worldwide. Six decades of experience in NAA has resulted in commonly applied analytical protocols, with measurements at about two to seven days and at three weeks after neutron irradiation. NAA with short half-life radionuclides enables an analysis turnaround time of one working day in principle. It also enables the detection of many important elements that cannot otherwise be measured with NAA based on longer half-lives. It may therefore provide competitive and, in some cases, even unique opportunities for an NAA facility. This opportunity is not fully seized by NAA laboratories due to the technical and analytical difficulties involved. This publication addresses all aspects of the implementation and optimization of NAA with short half-life radionuclides.

This TECDOC aims at illustrating the status in addressing safety and technological challenges encountered in the development, qualification and licensing of HBU nuclear fuels for Water Cooled Reactors (WCRs), summarizing the discussions held at a Technical Meeting organized by the IAEA in November 2022. This publication will provide useful insights for a future revision of IAEA Safety Standards Series No. SSG-52, Design of the Reactor Core for Nuclear Power Plants, as industry trends strongly signal a need to broaden the scope of this safety guide to include high burnup nuclear fuels. This publication is intended for Technical and Scientific Support Organizations (TSOs), regulatory organizations, operators, and research organizations.

This Safety Guide provides recommendations on the safe disposal of disused sealed radioactive sources in borehole disposal facilities. Sealed radioactive sources are used all over the world for a wide range of purposes, in areas such as health, industry, research and agriculture. These sources are usually managed safely while in use, but States often experience challenges in their management once the sources reach the end of their useful lives. Even though they may no longer emit sufficient radiation for their intended purpose, disused sources are radioactive and potentially hazardous, and they need to be managed as radioactive waste. Written for regulators and others involved in the development and management of borehole disposal facilities, the objective of this Safety Guide is to provide recommendations on the commissioning, operation, closure, institutional control and regulation of borehole disposal facilities for disused sealed radioactive sources, and small volumes of low and intermediate level secondary waste generated during the management of these sources. This Safety Guide can also be used as a basis for reassessing and, where appropriate, upgrading the safety of existing borehole disposal facilities.

The IAEA supports its Member States in increasing their use of research reactors. These reactors can be used for scientific research and training and for provision of commercial products, such as radionuclides for medical and industrial applications or analytical services of elemental analysis of various samples and objects. The IAEA’s Research Reactor Database (RRDB) indicates that the neutrons from miniature, small and medium size reactors are mostly used for neutron activation analysis (NAA). Over the years, the IAEA has stimulated NAA groups to focus on applications in which a large number of samples may be available for analysis. This publication provides a review of the performance of numerous NAA laboratories participating in interlaboratory comparisons from 2010 to 2022.

In recent years, significant experience of the effects of high wind and flooding on nuclear installations has been gained worldwide. These phenomena may simultaneously affect all the structures, systems and components important to safety at a nuclear installation site. By detailing the methodologies and providing case studies for the evaluation of meteorological and hydrological hazards, this publication supports IAEA Safety Standards Series No. SSG-18, Meteorological and Hydrological Hazards in Site Evaluation for Nuclear Installations. In the first part of the publication, wind hazards relating to tropical cyclones, tornadoes, extratropical storms, thunderstorms and wind-borne debris are discussed. The second part covers external flooding hazards (excluding tsunamis) relating to wind induced coastal flooding, wind generated waves on rivers, extreme precipitation and runoff events and the sudden release of impounded water.

This publication provides a summary of the International Conference on Effective Nuclear and Radiation Safety Regulatory Systems - Preparing for the Future in a Rapidly Changing Environment, including the opening and closing remarks, and summaries of all technical sessions and panels and summaries of side events. The conference served as a forum for identifying strategies to ensure regulatory resilience in a rapidly changing environment and to overcome life cycle challenges of nuclear installations and of activities involving radiation sources. It also focused on strengthening international cooperation and information sharing to improve regulatory effectiveness, agility and consistency in regulatory approaches related to new technologies. The major themes of the conference covered methodologies to increase public and stakeholder trust and regulatory credibility, best practices to sustain a competent workforce and develop the next generation of regulatory professionals and leaders, and programmes and strategies for the safe and secure use of radioactive material. This publication is intended for government ministers; senior officials and policymakers responsible for nuclear and radiation safety regulation; representatives of international, intergovernmental and non-governmental organizations (NGOs) with relevant competencies; regulatory bodies and other national competent authorities; and industry and other entities engaged in activities relevant to nuclear and radiation safety.

In this publication the basic principles of radiation physics, imaging and non-imaging instrumentation used, measurement of the administered activity, calibration procedures and methods for obtaining quantitative information on the biodistribution of the radioactive drug to be used with radioisotopes relevant to therapy are specified. It also describes methods for segmentation and registration of images acquired at different time points, strategies for fitting and integration of activity measurements over the time of treatment, absorbed dose calculations and derived dosimetric indexes with methods to estimate the overall uncertainty of different radionuclide therapies. The aim of this book is to fill the existing gaps in education and training of medical physicists on methods for patient-specific dosimetry. The overall objective of this book is to highlight the tools and methodologies to assure that radiopharmaceutical therapy is implemented through a dosimetry-guided individualized treatment approach.

This publication provides an overview of central nervous system (CNS) radiotracer development, discussing different aspects and stages of development. Non-invasive neuroimaging with radiotracers can provide functional information at the cellular level and contributes substantially to understanding the complex mechanisms of the functioning and pathophysiological processes in the human brain and is useful in certain diseases for patient stratification, treatment response monitoring and as an aided technique for drug development. The success of the development of clinically significant radiotracers depends on many factors such as the selected biological target, specificity and affinity of the radio ligand, pharmacokinetics of radiotracer and others. The information provided in the document will be useful to researchers, students and professionals engaged in the development and deployment of CNS radiotracers for clinical, research or drug development applications.

Cost-Benefit Analysis (CBA) is an economic appraisal tool which can be used to inform an investment decision, for instance, the construction of a nuclear power plant. In a CBA, the costs and benefits are accounted for as fully as possible, allowing estimation of the net economic benefit associated with the project relative to a without-the-project scenario, or an alternative investment proposal. This publication suggests an approach for conducting a CBA for a nuclear newbuild project as part of a feasibility study. It presents a CBA framework which is built around four key steps to characterize a project: the project’s objectives, alternatives to the project, and the broad context; a financial analysis, including estimates of costs and profitability; an economic analysis, taking a broader view to include additional benefits and costs to society; and a sensitivity and risk analysis to assign a confidence level to key financial and economic indicators and identify the circumstances in which the project will generate value. The publication includes a case study to illustrate the framework’s application and describes, for example, the methodology used for valuing environmental benefits, such as emissions and pollution reduction. The publication is aimed at all stakeholders involved in the planning and decision-making on a nuclear new build project.

This publication is a result of the Coordinated Research Project (CRP) F32008 "Global Monitoring of Nitrogen Isotopes in Atmospheric Waters" implemented by the IAEA’s Isotope Hydrology Section in 2018-2023. The CRP was focused on the determination of the spatio-temporal distribution of nitrogen isotopes in precipitation as a potential source of nitrogen pollution of water resources, especially of aquatic systems sensitive to eutrophication stressors. The principal method was based on the combined application of nitrogen isotopes with atmospheric chemistry and hydrometeorological techniques to better understand wet deposition processes and to characterize the origin and transformations of inorganic nitrogen loadings. This publication was supported by specialists in isotope hydrology, atmospheric and water sciences from a range of different countries around the world. Examples of their isotope applications have been provided to give context to the guidelines and recommendations made by this publication.