Radioprotection criteria for decommissioning of the 'Usina de Santo Amaro'

The first decommissioning process of a nuclear facility, in Brazil, has been carried out in the Usina de Santo Amaro (USAM), located in Sao Paulo city, where activities of milling of monazitic sands, including physical and chemical processing, were performed during about 50 years. This activities were interrupted in June 1992, due to technical and economical difficulties and to adequate the facility to the present radioprotection regulations. The decommissioning purposes include the release of the terrain for sale, the reuse of some equipment in other facilities and the sale of others. The Brazilian Nuclear Energy Commission (CNEN) has been following up this process of decommissioning verifying the accomplishment of release limits, in a way that the activities must be executed within the safety standards. This paper presents the release limits for the equipment, buildings and lands in restricted and unrestricted conditions, as well as effluent release limits. These criteria are conservative in order to assure the non dissemination of the contamination to the environment. (author)