This publication describes the work undertaken by Working Group 7, Assessment of Fate and Transport of Radionuclides Released in the Marine Environment of the IAEA’s Modelling and Data for Radiological Impact Assessments (MODARIA II) programme (2016–2019). The work carried out was a natural continuation of that completed during the first phase of the IAEA’s MODARIA programme (2012–2015) by Working Group 10, Modelling of Marine Dispersion and Transfer of Radionuclides Accidentally Released from Land Based Facilities. In MODARIA II, the degree of complexity of the models used was increased in order to effectively consider additional processes, specifically uptake by biota, and the spatiotemporal scales of the simulations were also expanded. General information on the simulation of radionuclides in the marine environment using dispersion and transport models was compiled. This is intended for scientists in Member States considering development or adoption of models for radiological assessment following incidents or emergencies involving releases of radionuclides into the marine environment.

The IAEA facilitated the co-operation on research and development among its Member States on the development and validation of computer codes for the design and safety analysis of nuclear power plants. The main objective of this effort was to bring together the current state-of­knowledge on uncertainty propagation in severe accident analyses that has been accumulated by experienced analysts with the aim of increasing the sophistication and competency of the practitioners in this field. This publication provides the contributions from four individual organizations from four Member States describing their employed uncertainty and sensitivity assessment methods applied in simulating the QUENCH-06 experiment performed at the Karlsruhe Institute of Technology (Germany) in December 2000. The QUENCH-06 experiment was designed to explore the behavior of nuclear fuel under oxidizing and quenching conditions during severe accident scenarios in light water nuclear reactors. Due to its comprehensive nature, this experiment was chosen as the benchmark for evaluating the performance of severe accident codes employed by participants in this coordinated research project. This publication is intended for nuclear engineers, researchers, code developers, experimentalists in nuclear energy fields, reactor vendors and developers, university professors and students, regulatory experts, and nuclear power plant planners.

The IAEA facilitated collaborative research among its Member States, in advancing the state of the practice in uncertainty and sensitivity methodologies for severe accident analysis in water cooled reactors. The primary aim was to evaluate the uncertainty and sensitivity associated with severe accident calculations, particularly concerning the progression and consequences of accidents in a generic CANDU type nuclear power plant under a postulated station blackout scenario. Key parameters considered in these analyses included hydrogen generation, event timings, and the release of fission products into the environment. The resulting publication showcases contributions from three institutions across three Member States, providing insights into their methodologies for uncertainty and sensitivity analysis in severe accidents.

As countries plan their low carbon energy strategies for the future, nuclear cogeneration—using nuclear power plants not only for electricity generation but also to provide simultaneously electricity and heat for applications such as district heating, hydrogen production, water desalination or to support industrial processes—is emerging as an attractive option for decarbonizing of various energy consuming sectors, while also boosting the efficiency of nuclear power plants. The publication includes an overview on the use of nuclear energy for cogeneration applications to achieve a future with clean and sustainable energy. It aims to increase the understanding of the role of nuclear cogeneration in climate change mitigation and to showcase the experience available in several Member States in the field of nuclear cogeneration. The publication is intended for decision makers, managers and engineers involved in nuclear cogeneration projects.

This publication includes existing experiences, lessons learned, challenges and future developments in the production of Ac-225 radiopharmaceuticals for Targeted Alpha Therapy (TAT). This publication will be utilized by all involved professionals in the Targeted Alpha Therapy field, specifying ideal production, formulation, quality control and regulatory aspects of various Ac-225 radiopharmaceuticals. The intended audience also includes radiochemists, radiopharmacists, and medical physicists.

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.

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.

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.

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.

<p class="MsoNormal">This publication is the outcome of a meeting of an
international team of experts that discussed various technical and scientific
details applicable to the production of important radionuclides such as ⁹⁹Mo,
copper-67 (⁶⁷Cu), scandium-47 (⁴⁷Sc) and actinium-225 (²²⁵Ac)
using the photonuclear route. This publication provides an overview of the
current state of methods for the photonuclear production of isotopes with a
particular focus on those medical radioisotopes that could be produced in
sufficient quantities for clinical use in nuclear medicine. It is intended for
scientists and technical professionals in the fields of electron accelerators
and radioisotope production. <span style="font-family:&quot;Arial&quot;,sans-serif"><o:p></o:p></span></p>

This publication provides an analysis of results from Integrated Safety Assessment of Research Reactors (INSARR) Missions conducted at research reactors during the period from 1995 to 2021. The analysis includes an assessment of trends, common issues, and other insights that are highly beneficial to Member States operating research reactors. This publication is also useful for self-assessment of research reactor safety. This publication is intended for use by operating organizations of research reactors, regulatory bodies and other relevant organizations involved in the safety of research reactors.