The annual reports of ENSI concerning the year 2010 are available on ENSI’s website.
The Surveillance Report pertains to the way ENSI perceived its responsibilities in 2010 and how it assessed nuclear safety in that year. ENSI monitors the entire life cycle of a nuclear facility, from initial planning, construction, commissioning and operation through to the post-operative phase, dismantling and the disposal of radioactive waste.
In order to provide an overview of the safety of Swiss nuclear power plants that is as comprehensive and realistic as possible, ENSI incorporates the individual aspects of preventive safety into an overall assessment. The methodology used is described in the Appendix of the Surveillance Report under the heading “Sicherheitsbewertung” [Safety Evaluation). The results for individual nuclear power plants are included in the plant-specific section of the report. For each plant/unit, the safety evaluation is represented in tabular form using a mosaic of different colours to display clearly the strengths and weaknesses of each plant. ENSI can thereby identify where improvements in preventive safety are required and operators must then submit their proposals for improvements. In recent years, ENSI has also given each nuclear power plant an overall qualitative assessment and for 2010, it has gone one stage further and introduced an element of differentiation in the overall assessment.
In accordance with the logic applied to safety evaluations, ENSI now assesses separately the safety impact of individual criteria, i.e. it has assessed the safety of design parameters, operating parameters, state and behaviour of the plant and the state and behaviour of human and organisational factors. This means that for the first time, plant design is the subject of a dedicated assessment and thus the overall evaluation shows clear differences between older and new facilities. As a result of extensive retrofitting over and above the international norm, ENSI rates the design safety of the older plants at Beznau and Mühleberg as “good”. Thanks to technical progress achieved in the 1970s, the design of the newer plants at Gösgen and Leibstadt is of an even higher safety standard and hence ENSI rates their safety as “high”.
Since the catastrophic events at the Fukushima plant in Japan on 11 March 2011, there has been a fundamental shift in the way the public regards nuclear facilities in Switzerland. Three days after Fukushima, the Swiss Federal Council suspended all applications for general licenses for the construction of new nuclear power plants. Two months later, Switzerland embarked on a political process that will see the phasing out of nuclear power for the purpose of electricity generation. This means a change to some of ENSI’s responsibilities as its previous assessment of new build projects is no longer relevant.
However, surveillance of the nuclear power plants currently in operation remains a key task. Monitoring existing nuclear power plants in Switzerland to ensure that they meet required safety levels is as important as it was before Fukushima. In addition, it is essential that we learn the lessons from events in Japan.