b' PIE results were published on UNtolerance of these cladding materialsto 8.7% burnup; the rodlet had kernels and UN-coated particlesunder simulated cyclic dryout condi- U-10Zr fuel sodium-bonded to irradiated up to 10 GWd/MTUtions.Results indicate that C26MHT9 cladding that had an internal in only 68 EFPDs in HFIR usingpossesses superior high temperatureFCCI barrier of chromium applied a MiniFuel capsule to accelerateoxidation resistance, mechanicalby Korean Atomic Energy Research burnup accumulation.Character- properties, and resistance to fatigue. Institute (KAERI).ization of fission gas release and A report was issued documenting an A focused ion beam(FIB)/transmis-microstructural changes indicatedevaluation of reactor performancesion electron microscopy (TEM) the performance of these fuels wasand safety impacts associated withexamination was performed on a good under test conditions. the use of increased enrichmentsample from a legacy EBR-II trans- A series of commissioning testsfuels in commercial power reac- mutation fuel pin (X501).This TEM (ATF-RIA-1A,B,C,D) were per- tors.Results showed that increasingexamination on irradiated metallic formed in TREAT using the Minimalenrichment reduces the quantity offuel is the first of its kind and sheds Activation Retrieval Capsule Holder- high-level waste disposed per unitlight on the microstructural changes Static Environment Rodlet Transientenergy generated, but increases thein irradiated metallic fuel caused by Test Appartatus (MARCH-SERTTA)natural resource requirements nor- the addition of minor actinides.device to validate simulations ofmalized to a gigawatt-electricity-per-The first examination of irradiated the design basis accident (RIA) andyear basis.Additionally, the slightlyfuel (U-10Zr-1Pd from AFC-3A) qualify new in-situ instruments. higher discharge burnup results inwas non-destructively examinedThe first TREAT experiment on (4)somewhat different activity levels ofwith pulsed neutrons at the Los ATF fuel rodlets, namely U3Si2the spent nuclear fuel and high- Alamos Neutron Science Center fuel pellets clad in both Zircaloylevel waste radioactivity at 100 and(LANSCE); analysis of the results and SiC, was completed.The100,000 years after fuel discharge. and comparison with destructive test was instrumented with bothUltimately, no neutronic or reactorexaminations will attempt to validate thermocouples and pyrometers, andsafety hindrances to employing lightthis NDE method for characterizing measured temperatures comparedwater reactor fuel with enrichmentslanthanide fission product migration well with pre-test predictions. greater than 5% were identified. and interaction with the cladding.Information obtained from the test The first FAST (Fission Acceler-The Advanced Reactor Experiments will be used to begin developmentated Steady-state Test) experiment,for Sodium Fast Reactor Fuels of fuel safety criteria for the newincluding metallic fuels with(ARES) collaboration was established fuel in design-basis reactivity- sodium-free annular geometry,with Japan to investigate transient initiated accident conditions. minor alloy additives for lanthanidefuel performance of advanced andRemote assembly of a MARCH- fission product control, and claddinghigh burnup fuel designs using SERTTA capsule in HFEF demon- liners as diffusion barriers againstlegacy oxide and metallic fuel pins strated a new capability to preparefuel-cladding chemical interaction, previously irradiated in EBR-II.previously irradiated fuel rod/rodwas fabricated and assembled and segments for irradiation testing inwill be installed in ATR Cycle 169A either ATR or TREAT. in early FY21. Thermal cycling experiments were PIE was initiated, and NDE com-performed in the Severe Accidentpleted, on a rodlet discharged from Test Station (SATS) on C26M andAFC-4C that had been irradiated Zircaloy-2 tubes to gauge accident 2020|AFC ACCOMPLISHMENTS 13'