SORPTION OF NICKEL ON GEOLOGICAL-MATERIALS

In CANDU (CANada Deuterium Uranium) fuel, Ni-59, with a half-life of 7 .6 x 10(4) a, is produced by activation of Ni impurities in the UO2 fu el and in the Zircaloy cladding. Sorption data are sparse for this ele ment on the solids of interest in the Canadian Nuclear Fuel Waste Mana gement Program (CNFWMP). A 2(3) factorial experimental design was used to examine the effects of [Ca], [Mg] and pH on Ni sorption from solut ions based on WN-1M, a reference synthetic groundwater widely used in the CNFWMP. Granite, biotite, K-feldspar, quartz, hematite and kaolini te were used as the solid phases. In general, sorption was greatest on hematite and least on quartz regardless of solution composition. Incr eased [Ca] and [Mg] and lower pH generally resulted in lower Ni sorpti on. The data indicated that Ni sorption may occur by a combination of ion exchange and surface complexation, depending on the nature of the sorbing solid.