Measurement of Krypton Grain-Boundary Inventories in CANDU Fuel

Abstract

A technique for measuring the Kr-85 grain-boundary inventory in irradiated fuel based on the conversion of UO, to U3O8 at low temperatures has been improved. The improvements include: 1) the use of a tracer isotope to account for release from the matrix during measurement of the grain-boundary inventory and 2) the cutting of samples from known locations. With these improvements it is possible to measure radial variations in the grain-boundary inventory. The measurements of the Kr-85 grain-boundary inventory can be combined with gamma mapping and ceramography to allow investigation of the connection between microstructure and fission-product distribution.