TopFuel 2015 in Zürich (summary of YG reporter)

The reactor fuel performance conference TopFuel 2015 takes place every third year in Europe and is organized by the European Nuclear Society (ENS). When the conference is not in Europe, the American Nuclear Society and the Atomic Energy Society of Japan, together with the Chinese Nuclear Society and the Korean Nuclear Society, host the event in their respective continent.

After the European conferences in Paris, France, in 2009 and in Manchester, UK, in 2012, the nuclear fuel community met in Zürich, Switzerland in September 2015. As usual the TopFuel conference represented a great opportunity to meet the whole nuclear fuel community. The participants include operators, vendors, nuclear regulatory authorities, technical support organisations (TSO), research institutes and universities worldwide. At the same time, several PhD students and postdoc researchers used the change to present their own results and to come and keep in touch with the nuclear fuel community.

The TopFuel 2015 conference was opened by the chair, Dr. Marco Streit (Paul Scherrer Institute, President of Swiss Nuclear Society) and the programme committee chair Johannes Bertsch (Paul Scherrer Institute). The openning session included a panel discussion under the title Upcoming Challenges Of The Fuel Market and was moderated by Tony Williams (Axpo Power AG, Switzerland). The fuel vendors GNF, Westinghouse, AREVA, ENUSA and Rosatom announced a 40% overcapacity in fuel assembly production in Europe. Several reasons exist for this, e.g. the immediate shutdown of several nuclear power plants in Germany after the 2011 accident at the Fukushima nuclear power plant. In general, several vendors expect a consolidation and / or collaborations in the European fuel market in the future. The openning session was completed by an overview of the activities of the OECD/NEA Expert Group on Accident Tolerant Fuels for Light Water Reactors, focussing on fundamental properties and behavior under normal operation and accident conditions.

After the opening session the participants had the choice between several parallel technical sessions. The sessions highlighted new trends, experiences, developments and R&D results in the fields of operation, operational transients, design basis accidents (incl. LOCA) and their modelling / simulation with computer codes. For example, new experimental results were presented by JRC-ITU (European Commission) regarding micro-hardness and local properties of high burnup UO₂ fuel. In spite of the increase of the fuel burn-up in many commercial reactors worldwide there is still R&D needed to understand and characterize in detail the processes ongoing in the high burnup structure occurring in the fuel pellet periphery.

Beside these topics the development of accident tolerant fuels was given attention in three sessions of the conference. As is well known, this topic has increased in interest in the last years. It seems that these developments are challenging for all involved parties. Nevertheless, Westinghouse pointed out that the first test with accident tolerant fuel in a commercial reactor was planned for 2022.

In addition, the wide spectrum of topics in the conference program was completed by two sessions about investigation of fuel for fast Gen-IV reactors (ASGARD) and three sessions about spent fuel.

After three days of interesting and great presentations, lectures, discussions and get-together of the fuel community the conference participants could take the opportunity to attend a technical tour. They could choose between a visit of the hot labs of the Paul Scherrer Institute (PSI), of the nuclear power plant Gösgen, or to go to Mont Terri Rock Laboratory for nuclear waste repository research all located in Switzerland.

TopFuel 2016 will take place in Idaho, USA, in 2016.