b'3.5 HIGH DOSE MATERIALS TESTINGHigh Dose Materials Testing for Fast Reactors Principal Investigator: Benjamin EftinkTeam Members/ Collaborators: Tarik Saleh (LANL), David Hoelzer (ORNL), Cheng Xu (TerraPower) and Stuart Maloy (LANL)T he main goal of the Nuclear Technology Research and Development (NTRD) program is to maximize nuclear fuel utilization while minimizing high level nuclear waste. In both the modified open and closed fuel cycle options these goals are accomplished through irradiating the nuclear fuels to very high burnup (40%) in a fast neutron flux. In order to develop fuels to accomplish this grand challenge, core materials (cladding and ducts) must be fabricated and tested to be able to withstand this challenging environment. This envi-ronment includes: 1) radiation to displacement doses greater than 400 displacements per ataom (dpa) that promote low temperature embrittle-ment, radiation induced segregation, high temperature helium embrittle-ment, swelling and accelerated creep; 2) corrosion with the coolant, and 3) chemical interaction with the fuel (FCCI). Thus, data is needed on the effects of irradiation on mate-Figure 1. Image of hot cell at Los Alamos National Laboratory (LANL) in Chemistryrials to doses greater than 400 dpa.and Metallurgy Research (CMR) Wing 9, where mechanical testing occurred.Project Description: Ferritic/martensitic (FM) steels and nanostructured ferritic alloys (NFA) are being developed for next genera-tion high dose reactor applications. Applications such as transmuta-tion of long lived isotopes in used 142 2020|AFC ACCOMPLISHMENTS'