b'Assessment of the mechanical properties of highburnup cladding is essential to establish a licensingcriteria for modern and advanced nuclear fuel designs in light-water reactors.ment with an average deviation less than 6%. This provides a high level of confidence that the planned transientsFigure 4. Rodlet holder and will achieve the targeted energyinstrumentation around rodlet of a partially assembled ATF-depositions for the remaining tests inRIA-1 capsule shown next to the ATF-RIA-1 series.an enhanced x-ray radiograph of ATF-RIA-1-A capsule prior to In July 2020 the MARCH-SERTTA teamirradiation (image courtesy of successfully completed the first highDavid Chichester).energy RIA test in a water environment to support LWR fuel safety testing in TREAT since the 1960s and the first integral test in the U.S. since the 1970s. The ATF-RIA-1-A capsule was irradi-ated with a 4.2% k/k TREAT transient clipped to 1260 MJ that deposited 860 J/gUO 2into the fuel specimen in a 90.5 millisecond full-width-half-max pulse. The results showed cladding temperatures measured in excess of 1200C.Disassembly and inspection of the capsule and rodlet is still pending. The ATF-RIA-1-B and C capsules have been assembled and are currently awaiting irradiation at TREAT and capsuled D and E are undergoing assembly and are scheduled to be irradiated in TREAT during September 2020. These experiments will complete the commissioning the MARCH- in coming years such as the Nuclear SERTTA capsule for integral RIA testingEnergy Agency (NEA) FIDES project in TREAT paving the way to supportingHERA, Westinghouse ATF, Framatome ATF and high burnup testing needs.ATF, General Electric ATF, and Nuclear These experiments provide the founda- Science User Facilities/Nuclear Energy tion to supporting a wide range ofUniversity Project (NSUF/NEUP) already planned experimental programsproject for coated claddings.2020|AFC ACCOMPLISHMENTS 107'