b'First Characterization of IrradiatedFuel with Pulsed Neutrons at LANSCEPrincipal Investigator: Sven C. Vogel (LANL)Team Members/ Collaborator: Thilo Balke (LANL & Purdue University), Charles A. Bouman (Purdue University),Luca Capriotti (INL), Jason M. Harp (ORNL), Alex M. Long (LANL), Danielle C. Schaper (LANL),Anton S. Tremsin (UC Berkeley), and Brendt E. Wohlberg (LANL)N Project Description: to enable the techniques demonstrated eutrons offer bulk, non-destructive characterization ofAdvanced post-irradiation examinationhere on a small disk sample to entire irradiated materials for whichmethods utilizing the unique capa- irradiated fuel capsules. The develop-other bulk methods, e.g., X-ray diffrac- bilities offered by pulsed neutrons arement of this cask is described elsewhere tion or tomography, are not suitable duedeveloped at Los Alamos National Labsin this report. Besides post-irradiation to the immense gamma background(LANL) Los Alamos Neutron Scienceexamination, the project also applies emitted from the samples. In particular,Center (LANSCE). Characterization ofpulsed neutron techniques to Advanced pulsed neutrons provide informationthe entire irradiated sample volume ofFuel Campaign (AFC) funded fuel devel-from the ability to resolve the neutronan irradiated fuel with pulsed neutronopment at LANL.energy using their time-of-flight. Thistechniques will ultimately identifyAccomplishments:enables the potential to utilize neutronnormal and abnormal regions withinThe technical goal of this project is to absorption resonance spectroscopy tothe entire irradiated volume, addapply pulsed neutron characterization characterize the spatial distributionotherwise unavailable data and guideto an irradiated fuel sample manageable of isotopes, so-called energy-resolveddestructive evaluation. These pulsedby remote handling (i.e., not requiring neutron imaging or neutron reso- neutron techniques therefore maximizea cask), both to gain insight on the nance imaging. As was demonstratedinsight from expensive irradiationparticular sample as well as a step previously [1-5], neutron resonancecampaigns. As a step towards thistowards characterizing larger amounts spectroscopy allows to characterizegoal, an Advanced Test Reactor (ATR)of irradiated fuel. the distribution of fission and neutronirradiated U-10Zr-1Pd sample was capture products non-destructively.characterized with an Nuclear ScienceFor this goal, a 6mm diameter, 1.8mm Besides neutron resonance-basedUser Facilities (NSUF) funded Rapidthick disk was cut from the AFC-3A-R5A radiography and tomography, neutronTurnaround Experiment (RTE) in theirradiation sample [6]. The post-irradia-diffraction provides information on2020 and 2021 LANSCE run cycles.tion isotope composition of the material the microstructure (texture, identifica- U-10Zr metallic fuels are researched asis expected to be 39.9 wt%. 238-U, tion of crystallographic phases andhost materials for potential transmuta- 46.5 wt.% 235-U, 0.3 wt.% 239-Pu, measuring their phase fractions). Bothtion fuels and the addition of palladium10.2 wt% Zr, 2.6 wt.% Pd. A custom of these techniques may ultimately bestrives to bind lanthanides, thussample holder was designed for pulsed applied to the entire bulk volume of anhindering fuel-cladding chemical inter- neutron experiments at LANL and the irradiation capsule to guide destructiveactions (FCCI). This is the first pulsedsample was loaded into that container. post-irradiation examination to identifyneutron characterization of an irradiatedFigure 1 shows the sample container, regions of interest. fuel at LANSCE. Part of the project isan aluminum rod with a cavity for the also the development of a cask designeddisk-shaped irradiated fuel sample. The aluminum rod was enclosed in a 42 2021|AFC ACCOMPLISHMENTS'