b'Mechanical Properties of ATF CladdingPrincipal Investigator: Benjamin Eftink and Robert HansenTeam Members/Collaborators: Hyosim Kim, Nan Li, Philip Peterson, Katelyn Baird, Peter Beck, Mathew Hayne, Carl Cady, Tim Graening, Tyler Dabney (University of Wisconsin Madison: UW-Madison), Kumar Sridharan (UW-Madison), Tarik Saleh, Fabiola Cappia, Jake Stockwell, David Kamerman This project hasA ccident tolerant fuel (ATF)Implementing accident tolerant cladding concepts aim tocladding concepts in the next improve high temperaturefew years requires confidence developed mechanicalsteam corrosion resistance forin the claddings mechanical testing protocols forinstances of off-normal conditionsperformance. Coatings applied by testing hoop directionin commercial light water reactorsdifferent deposition parameters/properties at high(LWR). One proposed concept is themethods show different responses temperatures and inaddition of a Cr coating on Zr basedto applied stresses/strains. By hot cells, as well ascladding tubes. These materials aremechanically testing these clad-evaluating coatingbeing studied for early implementa- ding tubes, we are understanding adhesion on newlytion in LWRs. Understanding howbetter how they will hold up in developed fuel the coatings respond to mechanicalservice conditions including high cladding concepts. stresses and strains, particularly inmechanical strain (due to internal the hoop direction of the tube, isgas pressure) accident scenarios. necessary before wide implementa- Extending capabilities to hot tion. Since the hoop direction iscells also allows testing of irradi-the direction that sees the greatestated cladding, whether from test stress in real world situations, it isreactors or commercial fuel rods, necessary to test the hoop directiondirectly enabling qualification of directly. Additionally, determiningcommercial ATF cladding concepts. the adherence of the coating isThis directly supports the Depart-important to understand. Quanti- ment of Energy objectives of safe, fying mechanical properties of ATFreliable, and thereby economical cladding concepts at service relevantoperation of the nations current temperatures and in hot cell envi- reactor fleet.ronments adds complications to testing and was the focus of FY23Accomplishments:efforts for this project. The first project goal of determining the high temperature strength of Cr Project Description: coated Zircaloy was achieved by ring This project had three main tech- pull testing of Cr coated Zircaloy nical objectives: i) high tempera- tubes at Los Alamos National Labora-ture hoop direction strength of Crtory (LANL). The tubes were coated coated Zircaloy, ii) implementa- by different processing conditions tion of hoop strength testing inas well as coating methods. Coating hot cells, and iii) measure highmethods included high impulse temperature adherence of the Crmagnetron sputtering (HiPIMS) coating applied to Zircaloy tubes.coated tubes provided by Oak Ridge National Laboratory (ORNL) as well 54 2023|AFC ACCOMPLISHMENTS'