Preparatory Study on Analysis of Fuel Debris (PreADES Project): Summary Report


The tsunami that followed the Great East Japan earthquake on 11 March 2011 led to beyond design-basis accidents at Units 1, 2 and 3 of the Fukushima Daiichi Nuclear Power Plant even though they had been shut down. Information available from ongoing investigations of the reactor cores indicates that these units experienced severe accidents involving core meltdown due to the total or partial loss of core cooling capabilities. 

The Preparatory Study on Analysis of Fuel debris (PreADES) project was recommended by the SEG on SAREF as one of several appropriate “near-term projects” to contribute to further international efforts to understand the Fukushima Daiichi accident and support decommissioning efforts. The PreADES project aims to summarise the knowledge and expertise related to debris characterisation collected from the different partners of the project and identify the needs for debris analyses that will contribute to the decommissioning of the Fukushima Daiichi Nuclear Power Plant. The goal of the project is to contribute to a better understanding of severe accidents and reactor safety assessments as well as to create appropriate and optimal methodologies for future debris sampling,
retrieval and storage. Consequently, the project outcomes are important for a future international project of sample examination based on “long-term considerations”.