RADIOISOTOPES

Radiation effects on the mixtures of inorganic oxides and water have been investigated for understanding radiation chemistry in solid–liquid systems. A number of studies revealed that energy deposition on solid phase stimulates reactions at the interface. This energy/charge transfer has been demonstrated by experiments to affect early stage of the radiolysis. However, the interfacial reactions subsequent to the energy/charge transfer require further studies. Here, we will see gaps between the basic understanding on the early stage and radiation effects connected to applications, taking zeolite/water and uranium oxide/water interfaces for examples. In the zeolite/water mixtures, the amount of hydrogen production is generally higher than that expected from the water content in the mixtures. The increases in hydrogen are interpreted by the concept of energy/charge transfer, but not quantitatively explained. The interfacial reactions on uranium oxides have an impact on the corrosion of nuclear fuel in contact with water, especially at the grain boundaries. However, the reactions are still unknown except for hydrogen peroxide and oxygen. Understanding of the interfacial reactions subsequent to the energy/charge transfer would bridge these gaps and enable to predict the radiation effects in applications.