Communicating about nuclear events: Some suggestions to improve INES

• We provide a critical analysis of the INES scale and suggestions to improve it.
• The rating criteria should be clarified to allow differentiation between events.
• An open scale should be used to differentiate between level-7 accidents.
• Additional guidelines should be provided for complex and evolving events.
• We provide suggestions to satisfy the public's expectations and restore trust.

This paper provides a critical analysis of the International Nuclear and Radiological Event Scale (INES) and its use, both from an epistemic and an ethical perspective. As very few papers have been dedicated to this subject, our critical analysis is mainly based on the INES 2009 User's Manual and on technical information issued by different nuclear agencies. Our critical analysis leads to suggest several elements, which could contribute to the improvement of the INES scale and thereby to a better communication about nuclear events. First, we show that multiple criteria are used to assign an INES rating, which could lead to an insufficient differentiation between events. In order to avoid this issue, we suggest to clarify the criteria that are used to assess the level of the event. Then, we show that level 7 of the INES scale is ill-defined as it does not allow to properly take differences in severity between disasters into account. In this regard, we recommend to use an open scale instead. Moreover, we highlight the fact that INES is able to take into account neither events with long-term evolution nor events involving multiple initiators. In this respect, we suggest providing additional guidelines and reflecting about the data on which to rely, in order to assess an INES level. Furthermore, we reflect on who should be rating a nuclear event and we recommend that, for severe events, an independent and plural agency should be in charge. Finally, we show why INES appears to be insufficient for a global communication, and we suggest to complement the INES rating with additional information in parallel.