Profit from borating concrete in the ITER biological shield

Reduction of the radiation doses in the ITER cryostat-biological shield region is important for the ITER maintenance. In this paper, the use of borated concrete in the biological shield is investigated. Reduction of the dose rates by factors of 2-3 are achieved immediately after shutdown and for many years thereafter when 0.1 g/cm/sup 3/ is added to the surface layer of the concrete biological shield wall.