Radiation impact of very low level radioactive steel reused in motorway tunnel constructions

*Considerable amount of radioactive materials arising from decommissioning of nuclear power plants may be classified as very low level radioactive waste. Various types of mentioned radioactive materials were analyzed in several international documents devoted to the optimization of radioactive material management with emphasis on concepts of recycling and reuse. One of these concepts of optimization is the conditional clearance of materials with their subsequent recycling and reuse in industrial sector. The concept of conditional clearance of radioactive materials into the environment follows international recommendations derived from the principles that the individual effective dose received by critical individual must not exceed some tens of μSv/yr. This paper deals with the radiation impact of recycling and reuse of conditionally cleared steel in industrial sector, specifically in motorway tunnel constructions. Scenario of the reuse of radioactive steel in form of reinforcing mesh and bars was created based on the data acquired from current motorway building practice in the Slovak Republic. The aim of the paper is to assess the radiation impact and to justify new specific clearance levels for radionuclides contained in steel reinforcement components in order to clear and reuse maximum amount of very low level radioactive steel considering mentioned dose criterion.