In September 2022, the International Commission on Radiological Protection (ICRP) organised a workshop in Estoril, Portugal, on the 'Review and Revision of the System of Radiological Protection: A Focus on Research Priorities'. The workshop, which was a side event of the European Radiation Protection Week, offered an opportunity to comment on a recent paper published by ICRP on areas of research to support the System of Radiological Protection. Altogether, about 150 individuals participated in the workshop. After the workshop, 16 of the 30 organisations in formal relations with ICRP provided written feedback. All participants and organisations followed ICRP's view that further research in various areas will offer additional support in improving the System in the short, medium, and long term. In general, it was emphasised that any research should be outcome-focused in that it should improve protection of people or the environment. Many research topics mentioned by the participants were in line with those already identified by ICRP in the paper noted above. In addition, further ideas were expressed such as, for example, that lessons learned during the COVID-19 pandemic with regards to the non-radiological social, economic and environment impacts, should be analysed for their usefulness to enhance radiological protection, and that current protection strategies and application of current radiological protection principles may need to be adapted to military scenarios like those observed recently during the military conflict in the Ukraine or the detonation of a nuclear weapon. On a broader perspective, it was discussed how radiation research and radiological protection can contribute towards the Sustainable Development Goals announced by the United Nations in 2015. This paper summarises the views expressed during the workshop and the major take home messages identified by ICRP.

The CONFIDENCE dissemination workshop “Coping with uncertainties for improved modelling and decision making in nuclear emergencies” was held in December 2–5, 2019 (Bratislava, Slovak Republic). About 90 scientists and decision makers attended the workshop. The dissemination workshop allowed the presentation of the CONFIDENCE project results, demonstration of the applicability of the developed methods and tools in interactive discussion sessions and the collection of feedback from the participants. The results were disseminated not only in the form of presentations and posters but also through interactive workshops where all participants were involved in round table working groups. A fictive accidental release scenario taking place at a nuclear power plant was developed and used by each work package in the workshop to provide the basis for interactive sessions and discussions.

In the framework of the European project CONFIDENCE, Work Package 1 (WP1) focused on the uncertainties in the pre- and early phase of a radiological emergency. One subtask was to analyse the propagation of uncertainties from ensemble dispersion simulations through a terrestrial food chain and dose model. Uncertainties that may occur in the modelling of radioactivity in the food chain were added to previously defined meteorological and source term uncertainties. Endpoints of the ensemble calculations within the food chain model included activity concentrations in the food chain,i.e.feedstuffs and foodstuffs, as well as the internal dose through ingestion. This paper describes the uncertainty propagation through a terrestrial food chain and dose model and presents some illustrations of the results.

Emergency preparedness and response systems for nuclear and radiological emergencies have to deal with decision-making in situations with relevant uncertainties. Consistent and appropriate protective measures must be decided before, during and after emergency situations. CONFIDENCE WP2 research helps to improve this decision-making process in the urgent response and the early response phase of emergency situations with potential major releases to atmosphere. This paper describes methods to reduce uncertainties in dose assessment for the population using data from stationary and mobile environmental monitoring programs. A special focus is given to identification of the measurement uncertainties of stationary and mobile monitoring systems. Methods to reduce these uncertainties and procedures to optimise mobile monitoring strategies are discussed. A first contribution towards assessing the quality of dose-rate measurements performed by the general population is made. In addition, the paper introduces approaches for advanced dose assessment tools using monitoring data and concepts for identifying critically exposed groups.

In the framework of the European project CONFIDENCE, Work Package 1 (WP1) focused on the uncertainties in the pre- and early phase of a radiological emergency, when environmental observations are not available and the assessment of the environmental and health impact of the accident largely relies on atmospheric dispersion modelling. The latter is subject to large uncertainties coming from, in particular, meteorological and release data. In WP1, several case studies were identified, including hypothetical accident scenarios in Europe and the Fukushima accident, for which participants propagated input uncertainties through their atmospheric dispersion and subsequent dose models. This resulted in several ensembles of results (consisting of tens to hundreds of simulations) that were compared to each other and to radiological observations (in the Fukushima case). These ensembles were analysed in order to answer questions such as: among meteorology, source term and model-related uncertainties, which are the predominant ones? Are uncertainty assessments very different between the participants and can this inter-ensemble variability be explained? What are the optimal ways of characterizing and presenting the uncertainties? Is the ensemble modelling sufficient to encompass the observations, or are there sources of uncertainty not (sufficiently) taken into account? This paper describes the case studies of WP1 and presents some illustrations of the results, with a summary of the main findings.

During the pre-release and early phase of an accidental release of radionuclides into the atmosphere there are few or no measurements, and dispersion models are used to assess the consequences and assist in determining appropriate countermeasures. However, uncertainties are high during this early phase and it is important to characterise these uncertainties and, if possible, include them in any dispersion modelling. In this paper we examine three sources of uncertainty in dispersion modelling; uncertainty in the source term, uncertainty in the meteorological information used to drive the dispersion model and intrinsic uncertainty within the dispersion model. We also explore the possibility of ranking these uncertainties dependent on their impact on the dispersion model outputs.

Between the end of September and early October 2017, Ru-106 was recorded by air monitoring stations across parts of Europe. In the environment, this purely anthropogenic radionuclide can be detected very rarely only. As far as known, Ru-106 is only used in radiotherapy and possibly in radiothermal generators. Therefore, the episode drew considerable interest in the monitoring community, although the activity concentrations and resulting exposure were far below radiological concern. Health consequences can be practically excluded except possibly near the source. Ru-106 in aerosols could be detected for several weeks and in some regions of Central and Eastern Europe tens, up to over 100 mBq/m(3) were measured as one-day means. Discussions about a possible source continue until today (early 2019). Atmospheric back-modelling led to trajectories likely originating in the Southern to Northern Ural region of Russia and possibly Northern Kazakhstan. Suspiciously, no other anthropogenic radionuclides have been observed alongside, except minute concentrations of comparatively short-lived Ru-103 (half life 39 d vs. 376 d for Ru-106). Due to the absence of other anthropogenic radionuclides, a reactor accident can be excluded, although both Ru isotopes are fission products generated in nuclear reactors. The exposure resulting from Ru-106 activity concentration in air exceeded 200 mBq x d/m(3) in some parts of Central and Eastern Europe. This leads to inhalation doses of up to about 0.3 mu Sv regionally, assuming the radiologically most efficient speciation, lacking better information, and inhalation dose conversion factors from ICRP 119. We show an interpolated map of the dose distribution over parts of Europe where sufficient measurements are available to us. Overlaying population density, we give an estimate of collective dose. The opportunity is also used to give a short review of origin, properties and use of Ru-106, as well as of accidents which involved release of this radionuclide.

NERIS is the European platform on preparedness for nuclear and radiological emergency response and recovery. Created in 2010 with 57 organisations from 28 different countries, the objectives of the platform are to: improve the effectiveness and coherency of current approaches to preparedness; identify further development needs; improve 'know how' and technical expertise; and establish a forum for dialogue and methodological development. The NERIS Strategic Research Agenda is now structured with three main challenges: (i) radiological impact assessments during all phases of nuclear and radiological events; (ii) countermeasures and countermeasure strategies in emergency and recovery, decision support, and disaster informatics; and (iii) setting up a multi-faceted framework for preparedness for emergency response and recovery. The Fukushima accident has highlighted some key issues for further consideration in NERIS research activities, including: the importance of transparency of decision-making processes at local, regional, and national levels; the key role of access to environmental monitoring; the importance of dealing with uncertainties in assessment and management of the different phases of the accident; the use of modern social media in the exchange of information; the role of stakeholder involvement processes in both emergency and recovery situations; considerations of societal, ethical, and economic aspects; and the reinforcement of education and training for various actors. This paper emphasises the main issues at stake for NERIS for post-accident management.

The Fukushima accident has demonstrated the possibility of long-lasting releases of radionuclides from a nuclear power plant over several weeks. Within the framework of the "PREPARE" research project one work package focused on testing emergency preparedness arrangements in various countries for the special case of long lasting emissions. The aim of this study was to test whether protection strategies included in current nuclear emergency planning in various European countries could adequately reduce the radiological consequences of Nuclear Power Plant accidents with long lasting severe releases. This paper presents an overview and the conclusions of this study, more details of the work can be found in the following articles.

The European project PREPARE (Innovative integrated tools and platforms for radiological emergency preparedness and post-accident response in Europe) aims at closing gaps that have been identified in nuclear and radiological preparedness following the first evaluation of the Fukushima disaster. It started February 2013 and ended January 2016. Fourty-six partners from Europe and Japan, among them universities, national research centres, operational emergency management centres and non-governmental organisations, performed research to close gaps identified following the Fukushima disaster. Among others, the project addressed the review of existing operational procedures for dealing with long lasting releases, cross border problems in radiation monitoring and food safety and further development of missing functionalities in decision support systems ranging from improved source term estimation and dispersion modelling to the inclusion of hydrological pathways for European water bodies. In addition, a so called Analytical Platform was developed exploring the scientific and operational means to improve information collection, information exchange and the evaluation of such types of disasters. The tools developed within the project will be integrated into the two decision support systems ARGOS and RODOS.

Created in 2010, the aim of the NERIS platform is to establish a forum for dialogue and methodological development among all organisations and associations taking part in decision-making of protective actions in nuclear and radiological emergencies and recovery in Europe. The objectives of the platform are to contribute to improving the effectiveness of current approaches for preparedness, promoting more coherent approaches, identifying gaps and need for further developments, addressing new and emerging challenges, and maintaining and improving know-how and technical expertise in this field. This paper describes the missions, the organisation and the activities of the platform as well as the key components of its strategic research agenda.

The assessment of radiological consequences for long-lasting releases was based on source terms and weather scenarios described in two previous articles. Four different institutions participated in radiological consequence assessment using their own source terms, weather scenarios, sites and characteristics of domestic nuclear power plants and atmospheric dispersion models. The results were evaluated in the context of national intervention levels. This assessment provided a good basis for an evaluation of the suitability of current nuclear emergency planning for potential accidents with long lasting releases.

The Fukushima-Daiichi nuclear power plant (NPP) accident has demonstrated the possibility of long-lasting releases of radionuclides from a damaged NPP over several weeks. The objective of this paper is to provide long lasting potential environmental source terms (ST) for the typical reactor units that are being in operation in various European countries. The main aim is to provide environmental ST for testing of the current off-site nuclear emergency planning in European countries with accident scenarios based on lessons learned from the Fukushima accident and to derive recommendations how to improve the current planning. There are described the environmental ST's for three, the most frequent, reactor types – Pressurizer Water Reactor (PWR), Boiling Water Reactor (BWR) a and VVER-440 (VVER = Russian acronym for PWR) that are under operation in Germany, Slovakia, Finland and Spain, but they can be considered as typical for NPP's under operation in another European countries, too.

The Fukushima-Daiichi accident has demonstrated the possibility of long-lasting releases of radionuclides from a nuclear power plant (NPP) over several weeks, which has led to the need to review if current procedures of external emergency planning are suitable for these situations. Under the framework of the “PREPARE” project one work package focused on “Review of the emergency preparedness in case of long-term emissions”. The aim is to test the current off-site nuclear emergency planning along Europe and to derive recommendations on how to improve it. In this context, a statistical study has been proposed by using potential long lasting release scenarios in combination with different weather conditions over a significant period of time (for instance one year) in some selected locations. This paper presents the results obtained in the development of accidental scenarios for a range of meteorological conditions representative for NPP sites in several European countries, i.e. Germany, Slovakia, Finland and Spain.