b'2.3 LWR IRRADIATION TESTING AND PIE TECHNIQUESRing Tension TestingPrincipal Investigator: Robert Hansen Team Members/Collaborators: Fabiola Cappia, Philip Petersen, David KamermanThis project meets theT he Idaho National Laboratorylable test parameter variations in(INL) Accident Tolerant Fuelthe RTT. And third, to develop (ATF) post-irradiation exami- processing methods to extract mate-challenge of obtainingnation (PIE) program is focused onrial properties more accurately. To accurate hoop strengthsobtaining accurate data on materialmeet these objectives, finite element from irradiatedbehavior of ATF cladding concepts.models of the RTT setup were devel-cladding through theIn anisotropic cladding, hoop direc- oped and analyzed, allowing precise ring tension test bytion mechanical properties are vitalreplication of the experimental proper configurationto qualification efforts. However,conditions and an in-depth under-selection, increasedaccurate hoop measurements arestanding of how the configurations understandingchallenging to obtain experimen- impact property measurements.of experimentaltally, and cannot be replaced by axial uncertainties, andmechanical testing. The ring tensionWhile several configurations of mathematical models totest (RTT) is an extremely usefulthe RTT have been proposed and correct data. method to determine hoop directionimplemented, the results vary properties in irradiated cladding,between configurations, and requiring only a small amount ofproperty measurements can be irradiated material per test. Severalsignificantly inaccurate due to a different configurations have beennon-ideal loading state. This project implemented, yet results will eitherinvestigated two leading configura-under- or overestimate the claddingtions, seen in Figure 1, comparing hoop strengths, depending on thethe measurements made from the configuration. Additionally, hot cellraw data. By using finite element testing environments introducemodels which feature known experimental uncertainties whichmaterial properties, the measured can lead to further errors in properties can be directly compared property measurement. For hoopwith material inputs that represent direction testing of irradiated clad- the correct results. This allows a ding using the RTT, it is important torobust evaluation of the accuracyunderstand these uncertainties andof these two configurations, to improve the accuracy of resultingwhich can be paired with three-strength measurements. dimensional stress and strain fields to understand discrepancies.Project Description:Further complicating matters, several The purpose of this research cantest parameters that can vary be summarized by three key objec- uncontrollably when testing irradi-tives. First, to compare two leadingated material in a hot cell environ-RTT configurations for accuracy inment. Deviation of specimens and strength measurements. Second, tofixturing from nominal dimensions, understand the effect of uncontrol-78 2022|AFC ACCOMPLISHMENTS'