Recovery, recycling and re-irradiation of enriched 104Ru metal targets for cost effective production of 105Rh

Nkemakonam C Okoye; Tim E Phelps; Anster Charles; Joshua B McCormick; Donald E Wycoff; John D Lydon; Mary F Embree; James Guthrie; Steven P Kelley; Charles L Barnes; Alan R Ketring; Heather M Hennkens; Silvia S Jurisson

doi:10.1016/j.apradiso.2021.109847

Recovery, recycling and re-irradiation of enriched ¹⁰⁴Ru metal targets for cost effective production of ¹⁰⁵Rh

Appl Radiat Isot. 2021 Oct:176:109847. doi: 10.1016/j.apradiso.2021.109847. Epub 2021 Jun 29.

Affiliations

¹ Department of Chemistry, University of Missouri, Columbia, MO, 65211, USA.
² University of Missouri Research Reactor Center (MURR), Columbia, MO, 65211, USA.
³ Department of Chemistry, University of Missouri, Columbia, MO, 65211, USA; University of Missouri Research Reactor Center (MURR), Columbia, MO, 65211, USA.
⁴ Department of Chemistry, University of Missouri, Columbia, MO, 65211, USA. Electronic address: jurissons@missouri.edu.

PMID: 34218122
DOI: 10.1016/j.apradiso.2021.109847

Abstract

Rhodium-105 (0.567 MeV β^-, 319 keV γ, 35.4 h half-life) was produced by neutron irradiation of enriched ¹⁰⁴Ru (>99%) over multiple decades. A method is reported to recover the previously irradiated ¹⁰⁴Ru (trapped in HCl as RuO₄^2-) as the metal. The ¹⁰⁴Ru was recovered in >93% yield and >98% enrichment. Neutron re-irradiation of the recycled ¹⁰⁴Ru produced ¹⁰⁵Rh, which was successfully radiolabeled with tetrathioethers in high yield. This recovery and recycling method for enriched ¹⁰⁴Ru makes ¹⁰⁵Rh production and utilization economical.

Keywords: (105)Rh production; Conversion to (104)Ru metal; Enriched (104)Ru; H(2) reduction; Neutron re-irradiation of recycled (104)Ru; Target recovery/recycling.