CONFIDENCE: COping with uNcertainties For Improved modelling and DEcision making in Nuclear emergenCiEs - DSA's participation

CONFIDENCE was a large three-year project (2017 - 2019) with 31 partner institutes from 17 European countries. The project aimed to reduce uncertainties and improve decision making in human and ecosystem radiological risk assessment and management in nuclear emergencies and existing exposure situations. A multidisciplinary approach was used to deal with all aspects regarding the radiological situation following an accidental release, from the prognosis of dispersion and its spatial-temporal evolution, to the offsite consequences, and the decision making to select, implement and evaluate remediation strategies, including the viewpoints of stakeholders. The scientific challenges identified were addressed through six interlinked work-packages (WPs). In WP1 "Model improvement in the pre-and release phase, through uncertainty analysis and propagation with an ensemble approach" DSA developed the sources term in a hypothetical accident scenario with the floating Russian nuclear power plant while towed along the Norwegian coast. The scenario resulted in significant and long-term consequences for southwestern Norway. In WP2 "Reduction of uncertainty in dose assessment for improving situation awareness and risk estimation" DSA contributed to a workshop and a report identifying critical points regarding strategies for international integration and consolidation of biodosimetry and retrospective physical dosimetry infrastructures in emergency preparedness and response. The work on uncertainty reduction in exposure assessment based on environmental monitoring showed e.g. that the uncertainty budget was dominated by the detector environment (sites, vehicles) and by the uncertainty in interpolation. Monitoring strategies were developed to reduce the interpolation uncertainty by increasing the network density through deployment of mobile measurement systems. DSA?s work in WP3 "Radioecological modelling: fit for purpose" in 2019 was mainly linked to adapting models for hot particle weathering and radionuclide migration in soils to be compatible with currently used food-chain transfer models (i.e. FDMT). Simulations were performed for various scenarios involving the deposition of hot particles. These results show that accounting for hot particle behaviour in soil can be important at considerable time periods (greater than several years) into the simulation but that for the immediate period post-accident other types of processes need to be focused upon. Further regionalisation of the FDMT model has been achieved by including a model to simulate Cs-137 transfer to reindeer. DSA was also involved in field studies concerning the addition of I-131 tracer to selected food crops. The objective of WP4 "Transition to long-term recovery, involving stakeholders in decision-making processes" was to improve the preparedness and response for the transition phase to long-term recovery after an emergency. DSA used a modified version of the above mentioned WP1 scenario as basis for a national workshop discussing priorities in food production. The discussions showed that the Norwegian stakeholders believe the Chernobyl experiences in Norway will make consumers accept the chosen remediation strategies for food production. It is also worth noting that the Norwegian stakeholders are reluctant towards soil removal and stopping agricultural production, even for scenarios with significantly higher contamination levels compared to the Chernobyl fallout ? and when discussing a product of relatively low dietary importance. An associated transnational Delphi survey among stakeholders showed that consequences for health and society are the first concern of the participants, and that food control appeared as the most important issue to be addressed during the transition phase. In WP5 "Social, ethical and communicational aspects of uncertainty management" DSA was involved in developing a methodology for the analysis of stakeholders' decision pathways linked to uncertainty management. The methodology was applied in a workshop with national and local stakeholders in Norway, discussing scenarios related to arrival of nuclear-powered vessels. DSA also arranged an international workshop on the impact of expert?s interactions on the resilience of affected people.

The CONFIDENCE project dealt with a broad range of aspects regarding the radiological situation following a nuclear emergency. The project outcomes are a range of suggested improvements to the decision-making process, from technical improvements to stakeholder involvement. Many of these have been implemented in national and international simulation tools and decision support systems and will help increase the quality and reliability of measures implemented and predictions made after an emergency. The project results will support the preparation and thus the optimisation of resources and will thus help society to recover faster from an emergency. Distrust of national authorities would be increased by lack of harmonisation in response and advice; the results of CONFIDENCE aims to aid a more harmonised response to future events. Knowing and effectively communicating uncertainties will enhance public confidence and sense of security as the possible distrust of authorities might be reduced.

CONFIDENCE aims to improve decision making for the protection of the population affected by nuclear emergencies and to minimise disruption of normal living conditions. This will be achieved through the reduction of uncertainties, where practicable, and the development of approaches to deal with uncertainty information. It will use a multidisciplinary approach dealing with all aspects regarding the radiological situation following an accidental release, from the prognosis of dispersion and its spatial-temporal evolution, to the offsite consequences, and the decision making to select, implement and evaluate remediation strategies, including the viewpoints of stakeholders. The scientific challenges identified will be addressed though 7 interlinked work packages (WP) to achieve the following objectives: - Tackle uncertainties in the pre- and early release phase of the accident (WP1) - Develop comprehensive software tools for the quick and efficient assessment of cancer risk to affected populations (WP2) - Develop approaches and tools integrating external and internal dosimetric monitoring data and link it with dose simulations and risk assessment tools (WP2) - Improve the capabilities of radioecological models used to predict activity concentrations in foodstuffs (WP3) - Engage national stakeholders to improve the preparedness and response in the transition phase (WP4) - Identify social and ethical issues related to uncertainty management in emergency and post-accident situations (WP5) - Support and improve communication of uncertainties (WP5 and WP6) and facilitate robust decision making taking into account the variability of the radiological situation and decision makers' preferences (WP6) - Develop training courses and educational material for professionals and students (WP7) The project is a collaboration between 31 institutes from 17 European countries. The project started in January 2017 and has a duration of 36 months.