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 ofsimulation models, data bases, user interfaces and system functionalities. However thesemany options resulted in heavy-weight and complex user interfaces difficult to handle bynon-experts. For this reason a user friendly and light-weight access to the RODOSfunctionalities was requested by the end users. This was fulfilled by the design andimplementation of a new user interface named RODOS-Lite. The main purpose of thisredesigned user interface is to gently lead operators through a sequential line of inputmasks, hiding rarely used parameters (defaults are set) from the operator but stillproviding the possibility to access them if necessary. Additionally, the interface isstrongly safeguarded to prevent operators from entering wrong input values. This isachieved by systematically checking input values and even suggesting occasionally bestestimate parameters. RODOS-Lite is complemented by various simple but neverthelessextremely useful features such as online access to Google maps or source termvisualisation.

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

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

Based on the framework for post-accident rehabilitation preparedness elaborated in theEURANOS project (Dubreuil et al., 2010), a Norwegian Pilot Study wasconducted in spring 2008 to test the suggested method. This article describes the methodused in the Norwegian Pilot Study and the outcomes of the co-expertise meetingsarranged.

Within the EURANOS project, 17 different demonstrations were conducted. The objective ofthese demonstrations was to apply a certain product in the operational environment of anemergency centre and to check its performance either in particular exercises or in theirdaily use. As a result of a demonstration feedback to the development team was provided,highlighting requirements for the further development of the product – if necessary. Asecond key pillar in the project was the intensive involvement of the RODOS Users Group(RUG) in the research activities. In particular all work packages related to the furtherimprovement of the RODOS system have been observed by the RUG. In some of the workpackages, the RUG was involved from the beginning and participated even in the designdocuments for the software development. Both mechanisms, the demonstrations and userinvolvement, guaranteed that the end user’s perspective was considered throughout allphases of the EURANOS project.

Two handbooks have been developed in conjunction with a wide range of stakeholders thatprovide assistance in the management of contaminated food production systems and inhabitedareas following a radiological incident. Emergency centres in Member States not involvedin the development of these handbooks were invited to take part in demonstrationactivities to establish whether the handbooks would be useful for the purposes ofcontingency planning and accident management. Some eight centres took part. Emergencyexercises or similar events based on scenarios involving contamination of the foodchainand inhabited areas were used. Feedback from all of the demonstrations was positive withconstructive criticism given on how to improve the navigation, structure and format of thehandbooks. All of the key improvements highlighted during the demonstrations were takeninto account and included in version 2 of the handbooks. Two additional demonstrationstook place in Denmark and Slovakia to investigate the appropriateness and applicability ofa stakeholder participatory process when applying the handbooks. These stakeholdersexpressed their willingness to discuss the issues at stake from contamination of foodproduction systems and inhabited areas and gave a clear commitment to continue theprocess.

MOIRA-PLUS is a decision support system (DSS) designed to address the mid and long-termissues after nuclear accidents causing the contamination of freshwater bodies andcatchments with radionuclides. It is designed to allow for a reliable assessment of thelong-term evolution of the radiological situation and of possible alternativerehabilitation strategies, including an objective evaluation of their social, economic andecological impacts in a rational and comprehensive manner. MOIRA also features a decisionanalysis methodology, making use of multi-attribute analysis, which can take into accountthe preferences and needs of different types of stakeholders. The main functions andelements of the MOIRA-PLUS DSS are described summarily, together with the conclusions fromend-user’s experiences with the system. MOIRA-PLUS has proven to be a mature system, userfriendly and relatively easy to set up. It can help to reassure the public by enabling arealistic evaluation of the complete impacts of possible recovery strategies. However, theusers also identified possibilities for further improvement of the DSS.