Reuse of Conditional Released Materials From Decommissioning: A Review of Approaches and Scenarios With Long-Term Constructions

Paper presents the overall scope and actual results of the project for evaluation of representative scenarios for reuse of conditionally released materials from decommissioning. Aim of the project is to evaluate the possibilities of reuse of conditionally released steels and concrete in technical constructions which guarantee the long-term preservation of design properties over periods of 50–100 years. Interaction of conditionally released materials with public is limited and predictable due to design and purpose of selected constructions and due to fact that in many scenarios these materials are embedded in non-radioactive materials such as bars in reinforced concrete. Worker’s scenarios for preparation, operation and maintenance of these constructions are analysed in detail including the manufacturing of elements for these constructions. Project aims to evaluate the scenarios of reuse of conditionally released materials in a complex way in order to develop the data for designers of scenarios and to evaluate the volumes of conditionally released materials based on facility (to be decommissioned) inventory data. The long-term constructions considered are bridges, tunnels, roads, railway constructions, industrial buildings, power industry equipment and others. Evaluation covers following areas: • Analysis of activities for manufacturing of reinforcement bars, rolled steel sheets and other steel elements and analysis of activities for construction of evaluated scenarios in order to evaluate the external exposure of professionals performing these activities; • Analysis of external exposure of professionals involved in operation and maintenance of the long-term constructions; analysis of external exposure of public groups which are exposed to evaluated constructions; • Analysis of internal exposure of public groups from the radionuclides released from the evaluated scenarios based on models for migration of radionuclides from the long-term constructions to critical groups of public; • Based on evaluation of external and internal exposure both for public and workers, maximal concentration of individual radionuclides is defined for construction elements of evaluated scenarios, manufactured from conditionally released materials; • Evaluation of volumes of steels and concrete in the frame of a decommissioning project which fulfil the defined radioactivity concentration limits. Visiplan 4.0 3D ALARA software is used for evaluation of external exposure of professionals and public, GOLDSIM software for evaluation of internal exposure of public and OMEGA code for evaluation of volumes of conditionally releasable materials. Several other parallel papers proposed for ICEM 11 are presenting selected details of the project.