Radioactive waste management is an inevitable consequence of nuclear technology. In the past it was often regarded as a perhipheral matter, easily dealt with, and having little impact on the economics of the fuel cycle. Gradually, over the last two decades, waste management has asserted itself as one of nuclear power’s most intractable problems. First, it is a problem of trying to understand through science the effects of discharging and disposing of man-made radioactivity to the general environment. Second, technologies for treating and disposing of the wastes, as well as techniques to verify their safety, must be developed. Third, and most problematically, a wide spread of public trust in the techniques of management must be nurtured. Disputes over each of these dimensions of the question exist in nearly all countries with nuclear programmes. Some of them may be near resolution, but many others are far from closure. Decommissioning, because it comes last in the nuclear life-cycle, is also the last important aspect of the technology to be considered seriously. In Britain, wastes arising from decommissioning, whether it is done slowly or quickly, are projectd to have an important impact on the scale of radioactive waste management programmes, beginning in the mid-1990s. It follows that decommissioning, contentious in itself, is likely to exacerbate the difficulties of waste management.