Large-scale production of Y and Zr/Y generators: A proof of concept study for a 70 MeV H cyclotron.

The large-scale production of Y with proton-induced reactions has been investigated from the perspective of new generation 70 MeV H cyclotrons. Tandem target configurations are presented for both the direct production of Y as well as for producing Zr/Y generators. Based on the relevant excitation functions, physical yields have been derived for Y production with YO/SrCO tandem targets and Zr production with Zr/YO tandem targets. Yields are presented for optimized targets (i.e. optimum yield) as well as for balanced thermal loads on the individual targets. Liquid Zr/Y generators have been produced using both natural Zr and Nb target materials, the former for dedicated productions and the latter as a byproduct by processing spent irradiated Nb capsules which normally would constitute radioactive waste. These stock solutions, which contain both the target material and Zr precursor, are retained virtually unchanged after processing except for the removal of Y on AG MP-50 macroporous cation-exchange resin. Methods are presented for the preparation of Nb stock solutions in hydrofluoric acid and Zr stock solutions in sulphuric acid. It is shown that multi-Ci productions of Y are feasible at a 70 MeV cyclotron facility, suitable for the needs of fracking applications. In addition, Zr/Y generators can provide Y with very high specific activity, suitable for labelling of biomolecules. LA-UR-20-24305.