Conclusions and recommendations from the 17th Workshop of the European ALARA Network 'ALARA in emergency exposure situations'.

The European ALARA Network regularly organises workshops on topical issues in radiation protection. In light of the Fukushima accident, the most recent workshop questioned the application of the ALARA principle in emergency exposure situations. This memorandum presents the conclusions and recommendations of this workshop. One of the outcomes is that the process of optimisation in emergency exposure situations should be flexible enough to be able to modify or refine decisions over the course of an accident. In the urgent phase, decisions must be made in a very time-constrained environment, based on scarce, uncertain and sometimes unreliable information. In this phase, optimisation and protection strategies are therefore developed and applied on the basis of conservative assumptions or 'reasonably foreseeable worst-case scenario' which could lead to an overestimation of the consequences. In the intermediate phase, knowledge of the situation improves, and more time is available to make the decision. This is reflected by adopting a less conservative approach, and transitioning to a more appropriate optimisation adapted as effectively as possible to the various exposure situations. When the situation is eventually stabilized (transition phase), there is time to shape the measures taken previously to reflect local conditions in the affected territories. In every phase, consideration should be given to the stakeholders, so that their needs and requirements can be incorporated as effectively as possible.