b'FAST to EBR-II Comparison and HT9 ApplicabilityPrincipal Investigator: Boone BeausoleilTeam Members/Collaborators: A. Swearingen, K. PaarenThis work is importantT he Fission AcceleratedThis work therefor attempts to Steady-state Test (FAST) testsinterpret the differences between are a key component of thethe two irradiation conditions. as it establishes theAdvanced Fuel Campaign (AFC)First, as-run comparisons are made divergence of FASTirradiation testing portfolio. Theto show thermal and irradiation tests from conventionalFAST methodology enables rapiddeformation of the cladding in both testing but validatesintegral testing of advanced fueltesting conditions. Second, EBR-II their applicability byconcepts partnered with controlfuel fluxes were applied to the HT9 clarifying the criticalpins for simple yet effectivecladding to determine the diver-life limiting phenomenacomparisons between fuel-claddinggence between the FAST and EBR-II of metallic fuels. systems. However, comparisonsirradiation performance.between performance necessitate parametric modeling assessmentsAccomplishments:to understand the gaps within theThe focus of this work are the general understanding of metalliccontrol pins of the FAST experi-fuel phenomena. ment, which are all solid, sodium bonded, 75% smear density Project Description: U-10Zr fuel in HT9 cladding. This project was executed toThese pins are important as they perform an assessment of theallow a comparison to be made applicability of a FAST irradiationbetween historical metal fuel experiment to understanding HT9tests (primarily in EBR-II) and cladding behavior when comparedthe novel designs within the to the performance of HT9 claddingFAST test matrix. The FAST pin in Experimental Breeder ReactorFAST-008 was irradiated within (EBR)-II experiments. Due to thethe Advanced Test Reactor (ATR) accelerated nature of a FAST experi- to 3.9 %FIMA (fissions of initial ment, the cladding is subjected tometal atoms, or atomic %) and neutron fluences approximately is currently undergoing post that of a conventional irradiationirradiation examination (PIE). test. Additionally, the long durationOther pins, listed in Table 1, are of the conventional experimentscontinuing on-going irradia-normally lends themselves to mean- tions. All of these pins have been ingful thermal creep behavior butmodeled, along with the entirety in a FAST test the stress impartedof the AFC FAST tests, within the on the fuel is done so more rapidlyMulti Object-Oriented Simulation while the duration is also reduced.Environment (MOOSE) using the These incongruencies betweenBISON fuel performance code. conventional testing in historicalThe configuration of the tests tests within EBR-II and the FASTand model relationship is shown tests require additional analysis.in Figure 1. The rodlets were 190 2023|AFC ACCOMPLISHMENTS'