Abstract
The activation of gold by environmental neutrons was used to study the effect of concrete buildings on the neutron flux and to estimate the thermal neutron flux in and around the building of Kinki University Training Reactor. The results showed that three ceilings of 34 g cm-2 thickness decrease the fast neutrons to 26% from its original value. However, the same reinforced concrete decreases the slow flux to only 62% from its original value. On the other hand, the thermal neutron flux at 283 m from the reactor center was two times higher than the environmental background. These results can give attention to the effect of concrete walls as a shielding around the reactors, especially those that have been hold near to the living environments.
