Solubility and dissolution behavior of 90SrF2 in aqueous media

A significant fraction of the heat generated by the discharged fuel from nuclear reactors results from the radioactive decay of the fission product 90Sr. Because of its relative abundance, moderately long halflife (T/sub 1/2/ = 28.6 yr), and heat output (0.93 W/g) the 90Sr is a candidate fuel for radioisotope power generation systems in terrestrial applications. To date, terrestrial applications for 90Sr have used strontium titanate (SrTiO3) or strontium orthotitanate (Sr2TiO4) as the fuel form. At Hanford strontium is recovered from the high-level waste generated in the fuel reprocessing operation and consists of a mixture of the desired radioactive isotope 90Sr and stable strontium isotopes. Freshly discharged reactor fuel also contains the radioactive isotopes 89Sr (T/sub 1/2/ = 50.5 days) and 91Sr (T/sub 1/2/ = 9.48 hr), but these isotopes have usually decayed to very low levels by the time the strontium is recovered from the fuel reprocessing wastes. The 90Sr isotopic content of the strontium will depend on the age of the wastes from which the strontium is recovered. A typical isotopic analysis of strontium recovered from recent Hanford wastes is given