b'Nuclear Energy University Project (NEUP) AwardNEUP 20-19374: Maintaining and Building upon the Halden Legacy of In-situ DiagnosticsPrincipal Investigator: Michael Corradini, University of Wisconsin-Madison (UW)Co-PIs: M. Anderson (UW), W. Marcum (Oregon State University, OSU)Team Members/Collaborators: H.J. Jo (Pohang Institute of Science & Technology, Pohang, South Korea (POSTECH)Senior Personnel: T. Moreira (UW), T. Howard (OSU)Graduate Students: A.B. Luna (UW), M. Moussaoui (OSU)G iven the expanding missionAccomplishments: of test reactors for accidentObjective 1: Review the current fiber tolerant fuel and advancedoptic sensor designs that would be fuels, it is crucial to maintain andsuitable for the nuclear environ-improve upon Halden Reactorsment (i.e., appropriate radiation, legacy of in-situ instrumentationpressure, and temperature condi-and sensor capabilities. In particular,tions) and identify and acquire the Halden has been a significant sourcefiber optic sensors to be installed in of experimental data to supportheated test rods.the nuclear industrys better under-standing of fuel-cladding responseAccomplishmentduring light water reactor (LWR)Our team led by UW investiga-transients and accidents: e.g., Loss- tors (A.B Luna, M. Anderson) of-Coolant-Accident (LOCA). Specifi- reviewed a number of past research cally, this type of LOCA testing isefforts on fiber-optic sensor (FOS) important given the interest indevelopment and submitted a advanced LWR fuels that seek toMilestone Report in 2021. In extend burnup beyond current regu- particular, the fiber embedment latory limits: i.e., using doped fuel ormethod was found to be most coated claddings that can minimizeappropriate. Researchers measured operational corrosion and oxidationtemperature profiles by embed-under accident conditions. ding the FOS sensors in grooved channels of stainless pipe heated Project Description:specimens. An ultrasonic additive This project seeks to provide real- manufacturing process was used time in-situ measurements duringto embed the FOS along the heater testing. Our focus is on developingsurface. For this work, distributed in-situ measurements of distributedtemperatures were measured temperature measurements and localalong the rod surface using these strain measurements for a simu- embedded optical fibers. The UW lated fuel rod (electrically heatedapproach was to incorporate this test rod) in out-of-pile test loops atapproach in the heated rod design.UW (steady-state) and OSU (LOCA transient). This project objectives areObjective 2: Develop the heated test listed below with the current accom- rod design that can accommodate plishments provided. the fiber optic sensors for distrib-uted temperature measurements 182 2023|AFC ACCOMPLISHMENTS'