In June 2009, the 5-year multi-national project EURANOS, funded by the European Commission in its 6th Framework Programme, reached its end, achieving most of the objectives addressed in the work programme. Partners from 23 European countries integrating 17 national emergency management organisations with 33 research institutes, aimed to enhance the preparedness for Europe’s response to any radiation emergency and long term contamination. Three handbooks to assist national and local authorities in the management of contaminated food production systems, inhabited areas and contaminated drinking water resources in Europe were developed in conjunction with a wide range of European stakeholders. Further guidance was prepared to support the decision making team in the lifting of early phase countermeasures. A governance framework for the sustainable rehabilitation of long term contaminated territories was developed and tested in France and in Norway. Considerable progress was made in developing a consistent set of models for calculating the best estimate of the current radiological situation in both contaminated agricultural and inhabited areas. These models were integrated in both the ARGOS and the RODOS decision support systems. Decision aiding components were improved to support the selection of management options with the help of multi criteria decision analysis procedures. A mass consistent wind field model was implemented together with a particle model for complex terrain. The migration of RODOS (Real-time On-line Decision Support System) to the operating system LINUX was completed. RODOS was completely re-engineered, taking into account the users’ recommendations from the demonstration projects and feedback from its operational use. This new version will build the kernel for the operational RODOS release in 2010 and new research activities related to the future improvement of RODOS.

Three handbooks have been developed, in conjunction with a wide range of stakeholders to assist in the management of contaminated food production systems, inhabited areas and drinking water following a radiological incident. The handbooks are aimed at national and local authorities, central government departments and agencies, emergency services, radiation protection experts, the agriculture and food production sectors, industry and others who may be affected. The handbooks include management options for application in the different phases of an incident. Sources of contamination considered in the handbooks include nuclear accidents and radiological dispersion devices; the most relevant radionuclides are included. The handbooks are divided into several sections which provide supporting scientific and technical information; an analysis of the factors influencing recovery; compendia of comprehensive, state-of-the-art datasheets for around 100 management options and guidance on planning in advance. A decision-aiding framework comprising colour coded selection tables, look-up tables and decision trees and several worked examples are also included. The handbooks can be used as a preparatory tool, under non-crisis conditions, to engage stakeholders and to develop local and regional plans. The handbooks can also be applied as part of the decision-aiding process to develop a recovery strategy following an incident. In addition, the handbooks are useful for training purposes and during emergency exercises. To realise their full potential, the handbooks should be customised at national, regional and local levels.

Generic guidance on the withdrawal of sheltering, withdrawal of evacuation and evacuation of sheltered populations (displacement) has been developed based on previously unpublished work in the UK and France and on input from stakeholder panels in Germany, Belgium, France and the UK. The guidance is a living document that can be developed further in the future, both in its generic form and also as customised versions in some Member States. The guidance outlines the many factors which influence the withdrawal of emergency countermeasures: official confirmation that any release has stopped; adequacy of monitoring data; radiological criteria; radiological protection advice; availability of resources; social and psychological needs; stakeholder dialogue; and communication strategy. The relative importance placed by decision makers on each of these criteria would vary according to the nature and scale of the accident and also on socio-political, economic and cultural perspectives. In the event of a radiological incident, decision makers will need to be in a position to construct a strategy for managing the withdrawal of emergency countermeasures. For larger scale, longer duration releases involving several nuclides, a management strategy is likely to be complex. The guidance therefore includes a series of checklists which have been developed in conjunction with stakeholders to take into account the main criteria and factors which should be considered.

The research activities under the work package CAT2 – improvement of decision support systems, focused on the one hand to improve the operability of the RODOS system but on the other hand to enhance RODOS and ARGOS with simulation models still missing in the portfolio of these two decision support systems. For RODOS, the work focused on the improvement of the atmospheric dispersion modelling in complex terrain and the improvement of the data assimilation functionalities. For both systems, the later phase models dealing with countermeasures in inhabited areas and food production systems have been considerably enhanced.

The European Model for Inhabited Areas (ERMIN) was developed to explore recovery options following the contamination of an urban environment with radioactive material. This paper discusses the user experience of ERMIN and in particular it concentrates on the development of a description of the urban environment and how that description affects the output. The user interacts with ERMIN by defining different regions on a map. A region may be an area in which a particular combination of recovery countermeasures is applied, or where a particular level of contamination is found, or where there is a particular type of urban environment. Most of the output from ERMIN is also presented as maps with summary information that allows the user to compare different countermeasure strategies. ERMIN has been implemented within two international nuclear accident Decision Support Systems; RODOS and ARGOS. Both systems have user interfaces that exploit geographic information system (GIS) technology which complement the ERMIN map based approach.

Predictions of the effects of agricultural countermeasures are an important part of the decision-making process following an accidental release of radioactive material into the environment. A new model has been developed for this purpose and integrated into the EU decision support systems RODOS and ARGOS. The model is based on the existing food chain model of RODOS and the previous model for simulating agricultural countermeasures in RODOS. The characteristics of the countermeasures and the supporting databases have been derived from the compendia and handbooks developed within the EURANOS project. A wide range of potentially practicable countermeasures is considered on timescales from a day to many years, and endpoints related to their imposition are calculated such that the economic and health impacts can be evaluated. This paper outlines the countermeasures methodology adopted and the databases used and discusses their applicability.

The Meteorological Pre-Processor (MPP) of the Decision Support System RODOS acts as interface between the incoming meteorological data from stations and/or prognostic models and the Atmospheric Dispersion Models (ADMs) used for predicting the spread of the accidentally emitted radionuclides. The MPP includes a diagnostic Wind Field Model (WFM) to ensure mass conservation of the calculated wind field. Its output is usable by simple and complex ADMs and it is applicable for highly complex topography and from micro- to meso-scales. The MPP has been tested for both real and artificial flow fields and it has been optimized to function with very short execution times and to give the most reasonable results under all terrain complexity and atmospheric stability conditions. DIPCOT (DIsPersion over COmplex Terrain) is a Lagrangian Puff / Particle model that has been implemented in RODOS to simulate radionuclides atmospheric dispersion over complicated terrain. For this purpose, it uses a certain number of fictitious puffs/particles which are assumed to move with the mean wind flow plus a random velocity component to simulate turbulent diffusion. The calculation of the gamma radiation dose rates in air due to the radioactive plume is calculated by a very fast method that takes into account the inhomogeneous 3-dimensional cloud shape. DIPCOT has been evaluated by comparisons to widely used real-scale experimental data sets: Copenhagen, Prairie Grass, Indianapolis and Mol. The integration of the above models greatly enhances the applicability of the RODOS system.

The Multi-scale Atmospheric Transport and Chemistry Model (MATCH) is used in the RODOS (Real-time On-line decision Support) system since more than 10 years for the long range atmospheric transport and dispersion calculations. With the start of the EURANOS project, several functionalities of the model at that time should be further enhanced. This included the better use of the meteorological information available in the numerical forecast data and the coupling to the source term data base of the RODOS system.

During the EURANOS project three atmospheric dispersion models ATSTEP (ATSTEP, 2007), RIMPUFF (RIMPUFF, 1999), and DIPCOT (DIPCOT, 2009) used in the RODOS (Ehrhardt and Weis, 2000) decision support system were subject of comprehensive comparison and validation studies. The aim of the comparison exercise was a harmonisation of the models for a sample of representative, non-complex dispersion and deposition situations in the distance range below 100 km. Despite of different modelling and parameterisation the models should deliver similar results under these conditions. Furthermore validation studies were carried out with ATSTEP and DIPCOT using measured meteorological and contamination data from tracer dispersion field experiments. After minor model and parameter modifications final comparison calculations of the models with realistic numerical weather prediction (NWP) data have shown satisfactory consistency of the results.

For four German nuclear power plant sites and for Risø, the site of the Danish nuclear research reactors now being decommissioned, Numerical Weather Predictions (NWP) of wind speed and direction have been compared to 10 minute averaged local measurements. For the German sites the comparison covers data for approximately three month, January to March 2009, for the Risø site for approximately two thirds of the year October 1998 to September 1999. For each site the comparison has been made for all measurement levels and both for the NWP analysis time and for the maximum available forecast time. Means and standard deviations of NWP minus measured data are given as tables for all measurement levels while scatter plots are presented for only a single measurement level at analysis time at each site. For Risø and for the site close to the North Sea plus for the inland site Philippsburg the predictions of wind speed are on average rather close to the measured, but for sites not far from the latter two, Krümmel respectively Obrigheim, the discrepancies are substantial.

Contemporary open source JAVA technologies implemented within the EURANOS project for the cross-platform re-engineering of the decision support system RODOS (JRODOS) were used also to redesign the Hydrological Dispersion Module (HDM) of this system. JHDM – the hydrological model chain of JRODOS contains models to simulate the radionuclide transport in the system “atmospheric fallout on watershed – river net” and calculate the doses via aquatic pathways. JHDM used for this purpose a limited number of the input parameters to characterize the hydrological properties of the catchment/river network of interest. The pilot implementation of JHDM for the Vistula river basin carried out by POLATOM and supported by the national hydrological institute, demonstrated good perspectives of the approach used in JHDM for the decision support in cases of accidental contamination of water systems. Particular needs for further improvements of the JHDM software system have been identified.

Within the EURANOS project data assimilation (DA) approaches have been successfully applied in two areas to improve the predictive power of simulation models used in the RODOS and ARGOS decision support systems. For the areas of atmospheric dispersion modelling and of modelling the fate of radio-nuclides in urban areas the results of demonstration exercises are presented here. With the data assimilation module of the RIMPUFF dispersion code, predictions of the gamma dose rate are corrected with simulated readings of fixed detector stations. Using the DA capabilities of the IAMM package for mapping the radioactive contamination in inhabited areas, predictions of a large scale deposition model have been combined with hypothetical measurements on a local scale. In both examples the accuracy of the model predictions has been improved and the uncertainties have been reduced.

In nuclear and radiological emergency and post-accident management decisions on countermeasures and remediation strategies have to be made. Whereas in the early phase decisions on emergency actions must be made in a very short time, according to emergency plans and dose thresholds, in the recovery phase complexity is higher. But there is also more time for evaluating alternative countermeasures and remediation strategies with respect to several goals. In this paper evaluation strategies supporting the decision makers throughout all phases are presented. The applied decision support techniques range from graphical presentations of decision relevant information about the alternatives for action to multi-criteria decision making (MCDM) methods. In particular methods to cope with several types of uncertainties inherent in the different phases are presented. By the integration of these techniques, the decision support system RODOS is able to provide support for more conscious, transparent and coherent decision making.

One key issue in the EURANOS project was the methodological and technological improvement of decision support systems, in particular the RODOS system, with respect to the practical application in operational emergency centres. The development process was mainly driven by the result of demonstration activities and responses obtained from the end-users in the emergency centres. The intention of this article is to give an overview of all major work items which have been performed within EURANOS with the aim of improving decision support systems. More details about several of these activities can be found in separate articles in this issue.

Decision makers must react in a prompt and appropriate manner in various emergency situations. The bases for decisions are often predictions produced with decision support systems (DSS). Actual radiation measurement data can be used to improve the reliability of the predictions. Data assimilation is an important link between model calculations and measurements and thus decreases the overall uncertainty of the DSS predictions. However, different aspects have to be taken into account for the optimal use of the data assimilation technique: different countries may have differing measurement strategies and systems as well as differing calculation models. The scenario and the amount and composition of radionuclides released may vary. In this paper we analyse the situation during and after an accident and draw up a list of recommendations that can help modellers to take into account the measurements that are best suited for data assimilation.

The decision support system RODOS (Ehrhardt and Weis, 2000) contains a large set of simulation models, data bases, user interfaces and system functionalities. However these many options resulted in heavy-weight and complex user interfaces difficult to handle by non-experts. For this reason a user friendly and light-weight access to the RODOS functionalities was requested by the end users. This was fulfilled by the design and implementation of a new user interface named RODOS-Lite. The main purpose of this redesigned user interface is to gently lead operators through a sequential line of input masks, hiding rarely used parameters (defaults are set) from the operator but still providing the possibility to access them if necessary. Additionally, the interface is strongly safeguarded to prevent operators from entering wrong input values. This is achieved by systematically checking input values and even suggesting occasionally best estimate parameters. RODOS-Lite is complemented by various simple but nevertheless extremely useful features such as online access to Google maps or source term visualisation.

The ERMIN model is a new implement developed to enable estimation of the radiological consequences in inhabited areas of accidents in nuclear installations. Similarly, AGRICP is a model developed to enable estimation of the radiological consequences of contamination of agricultural production areas. This paper provides a short overview of the background of the two models and describes the features enabled through their implementation in the ARGOS decision support system. The integration allows calculation of both dose rates and doses in particular areas, and can be used to evaluate the effectiveness and costs of countermeasure strategies.

Experience following the Chernobyl accident in the CIS and the EU has clearly demonstrated that policies and strategies for long-term management of extensive contaminated areas must give due importance to social, cultural, ethical, environmental, economic and political factors beyond the sole radiological protection and health perspective. What is at stake in the long-term response to such a situation is the sustainable rehabilitation of living conditions in affected territories, in a context in which each person can actively contribute to his own protection. Preparing or developing rehabilitation of living conditions in a territory affected by long-lasting radioactive contamination is a broader issue of governance as it must address all affected dimensions and articulate the actions of the various concerned actors at the local, regional and national level. To respond to this challenge, a specific research project was implemented by Mutadis, CEPN, NRPA and AgroParisTech from April 2004 to June 2009 in the framework of the EURANOS integrated programme. The overall objective of this project was “to develop a strategic and methodological framework that can inform or assist national authorities in Europe in establishing arrangements for the long-term management and the sustainable rehabilitation of living conditions in extensive areas that may be contaminated as a result of an accident or malevolent act involving radioactive material”. The proposed framework describes a two-steps method allowing national and local authorities together with key stakeholders to establish arrangements and preparation strategies in the perspective of long-term management of a radiological event. It may also be used to develop rehabilitation strategies in countries affected by long-lasting radioactive contamination. This framework aims to set up favourable conditions for stakeholders (in particular local communities) to engage effectively and sustainably in the cooperative development of post-accident preparation or management strategies. The first step of the method aims to frame the issue and identify conditions for stakeholders to engage in rehabilitation preparedness or management strategies. The second step aims to develop a local-national cooperation platform gathering local and national, private and public actors to develop together preparation or management strategies.