b'2.4 LWR PIEExaminations of BWR Lead Test RodsPrincipal Investigator: Jason Harp Team Members/Collaborators: Caleb Massey, Casey McKinney, Annabelle Le Coq, Nicholas Russell, Padhraic Mulligan, Jesse WerdenO ak Ridge National Labora- ORNLs partnership with tory (ORNL) supported the General Electric (GE) Accident Tolerant (ATF) and High BurnupGE continues to provide (HBu) program through severalPIE data necessary to efforts in fiscal year (FY) 2023. Post- support GEs mission of irradiation examination (PIE) wasenhancing fuel materials performed on IronClad segmentsfor BWR commercial irradiated in the Hatch reactor. Thisdevelopment in the near included mechanical property testing,and medium term.microstructure characterization, and activation analysis. Irradiation testing efforts were also initiated toreactor. The lead test rod, comprised of test candidate FeCrAl alloys in themultiple axial segments, was disas-High Flux Isotope Reactor (HFIR). Thesembled within the hot cells at the irradiations will explore both tradi- Irradiated Fuels Examination Facility tional mechanical testing geometriesat ORNL. Following alpha decontami-and for the first time tube geometriesnation, sectioned tubes were shipped that are representative of the diam- to the Low Activation Materials Devel-eters used in boiling water reactorsopment and Analysis Laboratory for (BWRs). Preparations were also mademechanical testing and microscopy. In to receive irradiated fuel from theFY 2023, initial investigations priori-Clinton Nuclear Power Station totized the examination of the end cap, further support GEs HBu efforts. the upper segment, and the mid axial Project Description: segment of the rod. Wire electrical Research in this area supports GEsdischarge machining was used to continued development of ATF forsection miniature tensile specimens future deployment in commercialfrom the end cap. The same technique reactors. Data generated by futurewas also used to extract ring pull exams on high burnup BWR materialand axial tube tensile specimens will support GEs efforts to extendfrom the individual tube sections. the discharge burnup of BWRs andSummarized mechanical testing data provide additional PIE regarding theis shown for these three characteristic performance of BWR fuel. locations in Figure 1. In this figure, specimens tested at room temperature Accomplishments: are shown in blue while specimens Mechanical tests and microscopytested at operational temperature were conducted on an IronCladare shown in red. Room temperature lead test rod irradiated in the Hatchspecimens routinely exhibited brittle 74 2023|AFC ACCOMPLISHMENTS'