A new and improved strategy for safe disposal of wastes from nuclear reactors is provided by a study of the geochemical means by which natural rocks and minerals retain the same elements that are present in these wastes. Certain natural minerals have demonstrated the capacity to immobilise radwaste elements for periods up to 2000 million years, and the fundamental reasons underlying this capacity are well understood in terms of the basic principles of geochemistry. Professor Ringwood outlines his SYNROC process, which utilises currently available technology to produce synthetic igneous rocks in which high-level wastes are incorporated. Fol lowing nature's example, the synthetic minerals making up these rocks are specially tailored to immobilise the radwaste elements. New methods of processing and storing SYNROC materials provide additional fail-safe barriers which further prevent nuclear wastes from entering the biosphere. Ringwood's principal conclusion is that the problem of isolating high-level nuclear wastes from the biosphere can be solved. This slim volume will present no storage problems: it may solve many.