On the utilization of heavy concrete for radiation shielding

This work is concerned with the use of ilmenite concrete (density=3.5 g/cm(3)) prepared from local materials as a radiation shield. Comparison with a previously investigated ilmenite concrete (density = 4.6g/cm(3)) including iron punching additions in its constituents have been carried out as this type of concrete was chosen for the construction of the biological shield for the second experimental reactor in Egypt. The study reveals that the ilmenite concrete under investigation is more effective for the attenuation of fast neutrons. In addition the production of the hard capture secondary gamma rays have been greatly decreased by eliminating the iron punchings from the constituents of the ilmenite concrete under investigation which is also preferable from the economical point of view. Total macroscopic cross section for fast neutrons, linear attenuation coefficients for gamma rays and the relaxation lengths both for the whole energy range and at different energies have been obtained and comparison with other published data has been done when it is available. Two empirical formulae have been derived which calculate the total flux of fast neutrons and gamma rays for different types of concrete at different thicknesses. Good agreement between measured and calculated values using the two formulae has been obtained.