Homogeneity tests on neutron shield concrete

In recent years, neutrons have been studied for application in fields such as material analysis and boron neutron capture therapy. To create a compact shield for these facilities, a neutron shield concrete is developed. Verifying the homogeneity of the concrete is important to ensure adequate shielding performance. In this research, neutron radiography images of the concrete are taken using the Thermal Neutron Radiography Facility (TNRF) of the JRR-3 research reactor, and the transmission ratio of the thermal neutrons were estimated. The results showed that the transmission ratio of the concrete was almost the same at each depth. (authors)