b'Barrier 3 3 3 4 3 4 3 3 48 29 77FCCI Mitigation Alloyadditives 4 4 3 2 3 2 3 3 52 21 73None 5 5 3 1 3 1 3 3 56 18 74Lotus 1 1 2 1 2 2 3 3 31 12 43Particle 2 1 1 1 1 1 3 3 26 10 36Fuel Geometry ODS Annular Grooved Split C 2 3 2 2 3 2 1 2 4 3 3 2 3 3 3 3 47 44 40 16 17 30 61 63 702 1 4 3 3 2 3 3 49 18 67Na-BondedLooseSlug 4 3 5 4 5 5 1 3 64 31 951 1 3 5 3 5 3 3Cladding Alloy AusteniticSST (D9,316) 5 5 3 2 3 4 3 3 56 27 83F/M steels(HT-9,Gr-92) 3 3 3 3 3 3 3 3 48 24 72Low/ microalloy U 3 2 2 1 2 1 3 3 39 12 51Fuel Alloy U-10Mo 3 3 2 2 2 2 3 3 39 19 58U-10Zr 3 3 3 3 3 4 3 2 48 25 73Importance(Weighting) 4 2 5 3 4 2 3 1 BaselineScore EnhancedScore OverallScoreFunctional Need The fuel system must be economic to fabricate in afresh uranium HALEU licensed fabrication facility The fuel system fabrication processes should be viablefor adaptation to include Pu and/or minor actinides The fuel system must perform reliably up to 10%burnup, 100 cladding dpa, and 600 C inner claddingtemperature The fuel system must enable long reactor operationcycles between refueling with predictable reactivityevolution using HALEU-based once-through fuelcycles The fuel system should perform reliably up to 20%burnup, 200 cladding dpa, and 650-700 C inner clad- ding temperature The fuel system should perform reliably under routinepower adjustments (e.g. daily load following cycle) The fuel system should perform reliably with theaddition of plutonium and/or minor actinides The fuel system must enable passively safe plantdesigns (no damage in DBA, no cladding failure inBDBA) for baseline fuel performance requirements The fuel system must enable passively safe plantdesigns (no damage in DBA, no cladding failure inBDBA) for opportunity fuel performance requirements The fuel system must be viable for direct disposal ina once-through fuel cycle, i.e. must not create severechemical interaction hazards in storage, transporta- tion, and disposition or be considered mixed waste The fuel should facilitate reprocessing in closed-fuelcycles by electrorefining methods (or maybe aqueous)Category Influential Considerations Labor, duration and quantity of processing steps Cap. investment, size/cost of facility and equipment Utility demand (electricity, natural gas, etc.) Baseline Tolerances and repeatability -yield rate Magnitude and hazard level of waste disposal Raw material cost (fuel, cladding, hardware, consumables) Process continuity and/or batch size (crit. limits) Ability to recycle/recover scrap Enhanced Acceptable range for special process controls Ability/difficulty inspecting product characteristics Isotropy of fuel swelling Fuel density and swelling free space (smear density) Cladding mechanical properties evolution Baseline Strength and defect propensity in end cap weld Nuetron absorption of materials in active core Cladding/duct atom displacement void swelling/bowing Constituent redistribution, FCCI,cladding wastage TH perfomance, heat flux, heat transfer rate Fuel cladding mechanical interaction Enhanced Fission gas release, plenum pressure accumulation Solid fission product driven fuel swelling Fission gas driven fuel swelling and pore interconnection Reactivity change from axial expansion, melt relocation,& sodium expulsion Baseline Fuel thermal conductivity (stored energy) & meltingtemperature Cladding fuel eutectic penetration Cladding mechanical properties (resistance to hightemperature deformation, fuel thermal expansion, &pressure driven rupture) Enhanced Coolant/fuel chemical compatibility, benign behaviorin run beyond cladding breach, non-violent behavior incladding burst Propensity for fuel particle ejection & channel blockage Chemical compatibility of fuel system constituents withBaseline air/water Ability to separate constituents and recycle into newEnhanced fuel pins Figure 1. Design options ranking spreadsheetFabrication NormalOperation Off-Normal Scenarios Back-end2022|AFC ACCOMPLISHMENTS 137'