Decommissioning Strategies Worldwide: A Re-Visited Overview of Relevant Factors

This paper highlights current trends and developments in selecting decommissioning strategies worldwide. Radiological conditions, spent fuel and radioactive waste management, funding, economics and the development of suitable technology are some common factors for taking decisions on the timing and circumstances of decommissioning. Although safe enclosure is the default option for many shut down facilities typically due to lack of ready cash, delay in dismantling may have serious disadvantages such as loss of expertise and long term uncertainties. Currently, of the many large nuclear installations permanently shut down, only a fraction have been or will be in the near term totally dismantled and decommissioned to unrestricted release state. A trend towards immediate dismantling seems to emerge in some countries, and is supported by IAEA positions, but this appears to be due to country-, site- or plant-specific conditions of limited generic applicability. In recent years, and often as the result of international efforts, the situation is evolving, and provisions and infrastructures including funding are being established to cope with decommissioning challenges. This factor seems in principle to encourage immediate, total dismantling. However, the worldwide overview of decommissioning strategies does not offer a clear pattern. New factors have come into being, such as stakeholder opinions, in particular those of local communities, and now play a significant role in decision-making. The conditions of the nuclear industry at large (e.g. the “nuclear renaissance”) considerably changed over the last few years and are going to affect decommissioning in the near future. Strategies such as restricted release (brownfields), incremental decommissioning or entombment seem to offer new prospects. The author reviewed first the worldwide situation around the year 2000, and offers in this paper some reflections about changed world’s conditions and how these affect the decommissioning scenarios.