Tritium Ingress into Candidate Structural Materials for Fusion Reactors
Retention of tritium in structural materials of a fusion reactor is a concern for tritium accountancy, maintenance, and decommissioning. Plasma facing materials will be exposed to high temperatures, neutron damage and hydrogen isotopes. The damage caused by these conditions is a large area of exploration for fusion, with many questions still to be answered. Several studies have examined neutron damage and deuterium retention separately, however the use of tritium is limited. In this work, several candidate structural materials have been exposed to pure tritium and then the tritium ingress depth profiles have been measured. Depth profiles are generated using a series of acid etches, followed by liquid scintillation counting of the acid used. Materials studied include a Nanostructured Ferritic Alloy (NFA), Eurofer 97, nickel-based alloys and austenitic stainless steels. Comparisons are drawn between these materials and the reference 316L stainless steel. This work was carried out as a collaborative effort between the University of Rochester’s Laboratory for Laser Energetics (LLE) and the United Kingdom Atomic Energy Authority (UKAEA), funded by a BEIS Tactical Grant