[en] A survey of the literature on the solubility and aqueous species of technetium, radium, and iodine was conducted, with special emphasis on salt repository brines. The elements reviewed here were three of a total of seventeen elements reviewed by participating laboratories. Comprehensive tables of solid compounds and aqueous species for each elements were screened according to a uniform set of procedures. Technetium solid compounds selected for further solubility studies in repository brines were TcO₂/center dot/nH₂O, TcS₂, and Tc₂S₇. Aqueous species of interest were those associated with solubility measurements and complexing ligands such as phosphate and carbonate species. The least soluble compounds of radium are expected to be RaSO₄ and Ra₃(PO₄)₂, although thermodynamic estimates predict that RaF₂ and RaCO₃ may also be of some concern under particular circumstances. In cases where concentrations are too low to precipitate a pure radium phase, it appears probable that the concentration of Ra²⁺ in a brine may be limited by formation of solid solutions with insoluble compounds of other Group II A elements. The aqueous species of most concern are those associated with the least soluble solid compounds of radium, e.g., phosphate, sulfate, fluoride, and carbonate. No solid species of iodine were identified as important in repository brines. The species of iodine of major interest are those involved in the hydrolysis of I₂ to I/sup /minus// and IO₃/sup /minus//, including trihalide ions and HOI. 40 refs., 5 figs., 21 tabs