Members of the QUENCH-ATF joint undertaking gathered on 26-27 February 2026 in Paris, France, for the Programme Review Group and Management Board meetings. The QUENCH-ATF project aims to investigate the behaviour of accident-tolerant fuel (ATF) claddings in design basis accidents and beyond design basis accident scenarios. The project consists of three bundle tests at the QUENCH facility at the Karlsruhe Institute of Technology (KIT), Germany. Two of the tests have been performed, and the last test is to be carried out in mid-2026.
The ATF designs investigated in this project are chromium-coated Zr alloy claddings, which aim to reduce the hydrogen and heat release during postulated accidents while maintaining or even improving the fuel assembly properties and performance during normal operation. While previous ATF developments relied on single rod experiments or tests with external heating, the QUENCH facility can test fuel claddings to beyond design basis accident conditions in a bundle geometry with internal heating. Testing materials in these prototypical conditions provide new and unique data on the behavior of these novel chromium-coated claddings. This serves both to improve the understanding of the ATF safety significance as well as to help the development of the severe accident simulation models.
During the meeting in Paris the participants reviewed the new examination results of previous experiments, discussed their implications, and were presented with the updated results of the joint post-test simulation benchmark. The chromium coating of the cladding samples for the third test had been prepared by the UK National Nuclear Laboratory (UKNNL), and the coated claddings had been received at KIT just before the meeting. The test preparations continue, with the aim of conducting the last test during the summer.
The QUENCH-ATF project is set to continue until late 2026, after which the aim is to start a continuation project with a new scope and more partners. The work scope for Phase 2 was discussed in a separate workshop in parallel with the project meeting. This new project aims to build on the experience gained from the first project and welcomes new participants.
