b'The completion of the first fast reactor experiment in TREAT with previously irradiated fuel established unique capability and matured a diverse transient testing team to complete the JAEA-INL ARES project on high burnup fast reactor fuels.The experiment modules were thenproject team which can be leveraged transferred to HFEF for fuel loadingfor future THOR experiments with and sodium wetting. Once insidepre-irradiated fuel specimens.HFEF, the hinged portion of theFollowing assembly of THOR-M, experiment module was rotated,the THOR-MOXTOP-1 capsule was the capsule top was opened, and thesuccessfully loaded in HFEF and pre-irradiated fuel pin was inserteddelivered to TREAT for irradiation. into the capsule and internal heatThe THOR-MOXTOP-1 transient sink until fully seated. After fuel pinoccurred in TREAT in July 2023, loading, the sodium was bonded tosuccessfully completing the first the specimen cladding, the capsuleirradiation of previously irradiated was closed, and instrumentationfuel pins in the THOR capsule. was checked prior to shipmentFigure 4 shows a photograph of the to TREAT for irradiation. Figureinstrumentation checkout which 3 shows a photograph of the pre- occurred on the THOR-MOXTOP-1 irradiated fuel pin loading into theexperiment prior to shipment to THOR-MOXTOP-1 capsule. TREAT. The completion of the first The THOR-M experiment was thepreviously irradiated fast reactor first THOR capsule to go throughexperiment in TREAT paves the way fuel loading and assembly insidefor additional THOR experiments HFEF, with the intent of providingwith pre-irradiated SFR fuels and has assembly experience to the THORsignificantly advanced preparations project team. The THOR-M experi- for the following water capsule and ment was successfully loaded andsodium loop experiments with high assembled in March 2023 andburnup fuels.further proved the design of the remote handling equipment devel-oped for assembly. The THOR-M experiment provided expertise to HFEF operations and the THOR 2023|AFC ACCOMPLISHMENTS 181'