Overview and progress in the European project: “Supercritical Water Reactor – Fuel Qualification Test”

• Structure and objectives of the European project “Supercritical Water Reactor – Fuel Qualification Test”.
• Progress in design and analyses of the experimental facility for qualification of fuel under supercritical water conditions.
• Results of material tests of potential cladding materials – stainless steels.

The Supercritical Water Reactor (SCWR) is one of the six reactors being investigated under the framework of the Generation IV International Forum (GIF). One of the major challenges in the development of a SCWR is to develop materials for the fuel and core structures that will be sufficiently corrosion-resistant to withstand supercritical water conditions. Previously, core, reactor and plant design concept of the European High Performance Light Water Reactor (HPLWR) have been worked out in substantial detail. As the next step, it has been proposed to carry out a fuel qualification test of a small scale fuel assembly in a research reactor under typical prototype conditions. Design and licensing of an experimental facility for the fuel qualification test, including the small scale fuel assembly, the required coolant loop with supercritical water and safety and auxiliary systems, is the scope of the project “Supercritical Water Reactor – Fuel Qualification Test” (SCWR-FQT) described here. This project is a collaborative project co-funded by the European Commission, which takes advantage of a Chinese – European collaboration, in which China offers an electrically heated out-of-pile loop for testing of fuel bundles. The results of these out-of-pile tests on an electrically heated, but otherwise identical, fuel assembly shall be used as a pre-qualification experiment as well as for providing data for CFD and system codes validation. A significant part of the design and the necessary structural, CFD, neutronic and safety analyses had been completed. The design of the facility, and especially of the test section with the fuel assembly, as well as the most important results of the above mentioned analyses are presented. Material test results of the stainless steels considered for the fuel cladding are briefly summarized. Finally, important outcomes and lessons learnt in the “Education & Training” and “Management” work packages are presented.