A composition is prepared by heating particles of a nuclear fuel material in a metal salt that decomposes below 1000.degree. C. to form a metal oxide. Magnesium nitrate hexahydrate is an example of such a metal salt. A resulting composition includes the particles homogeneously dispersed in a matrix of magnesium oxide. After the composition is used in a nuclear reactor, the now spent composition is removed, cooled, and the matrix is dissolved away from the spent particles, which can be reused in another nuclear fuel composition. The recovered fuel particles also contain some fission products that provide a radiation barrier that discourages theft of the recovered fuel particles.
STATEMENT REGARDING FEDERAL RIGHTS
 This invention was made with government support under Contract No. DE-AC52-06NA25396 awarded by the U.S. Department of Energy. The government has certain rights in the invention.