b'L D R D S U C C E S S S T O R Y The detection of argon-37 above background levels is a clear and unique indicator of the underground detonation of a nuclear device. Through LDRD, researchers collaborated with the Idaho Accelerator Center to demonstrate the ability to produce high quality samples of standard argon-37 to enhance treaty verification.A LDRD project improved global capabilities to establish evidence of an underground nuclear explosion by better understanding the energy spectrum of chemically separated argon produced through irradiation.Supporting the development andF Y 2 0 I M PA C Tdeployment of the U.S. high-assay, low- Actinium-225, neptunium-235 and -236, enriched uranium (HALEU) fuel cycle plutonium-236, and short-lived, low yield fission product isotopes are critical to nuclear science research areas INL enables the deployment of advanced reactors by providing anranging from advanced nuclear fuels development to astrophysics interim supply of HALEU from recovered and downblended highlyand fundamental nuclear science. Actinium-225 and scandium-47 enriched uranium from current Experimental Breeder Reactor-II (EBR- are needed for new and improved cancer treatments. INL researchers II) spent nuclear fuel stocks. This supports advanced reactor developersinvestigated new photonuclear production pathways in combination and aligns with INLs commitments to the state of Idaho, specificallywith novel, rapid chemical separations methods to make these the stabilization of EBR-II fuel by 2028 and disposition of waste byradioisotopes available on demand, in larger quantities, at significantly 2035. EBR-II metal HALEU is directly suitable as a fuel feedstock for fastlower cost, and with less radiation exposure than previously possible. spectrum reactors, but it contains chemical impurities and radioactive contamination that preclude its immediate use as a fuel feedstock for thermal spectrum reactors. To address the variety of fuels required for demonstrations (metals, oxides, thermal, and fast spectrums), INL is conducting a polishing campaign to produce material that meets thermal spectrum specifications for recovered materials. This is accomplished in collaboration with Pacific Northwest National Laboratory and Argonne National Laboratory scientists.INL developed novel ways to produce rare isotopes needed for research, security, and medicine.INL produces uranyl peroxide, uranium trioxide, and uranium oxide and removes impurities to support thermal spectrum fuel fabrication needs.11'