Calculation of γ radiation converted to thermal energy in nuclear reactor shielding facilities

The heat generation within a shield can be a primary consideration in its design, especially when the shield is for high power reactor in which rather large temperature increases can be expected. The heating up of the shield itself can be utilized via a suitable flow of water on the outside of the said shield or, in the case of thermal shields, using the nuclear reactor coolant leading to energy saving in nuclear power plants. The thermal energy generation rate inside the shielding materials is calculated using the build up factor method for multi-energy photons emitted from disc geometry radiation source and a comparison has been made in order to estimate the percentage of energy captured, and therefore saved, inside the shielding layers. In this paper the use of build up factor is suggested for thermal energy estimation in shielding materials such as Al, Fe and Pb and comparison with the results produced from the application of MCNP-4A computer code. This is a continuation of the work done by Bakos [Bakos, G.C., 1995. Benchmark data for g-rays emitted by an Na-24 source penetrating stratified shielding slabs. IEEE Trans. Nucl. Sci. 42 (2), 61–65].