An Overview of Interfacial Radiation Chemistry in Nuclear Technology

Abstract

Interfacial radiation chemistry is of key importance in nuclear technology because most materials in the vicinity of radioactive materials in nuclear power plants, reprocessing plants, and repositories for nuclear waste are exposed to ionizing radiation. Corrosion is a crucial issue for the long‐term performance and safety of these installations. Nevertheless, this field is still fairly undeveloped. In this paper, the current state of the art with particular focus on reactions between aqueous radiolysis products and metal or metal oxide surfaces is discussed. The general reactivity of hydrogen peroxide and the hydroxyl radical towards oxide surfaces is discussed on the basis of recent experimental results and DFT calculations. More specific discussions on radiation‐induced surface processes in a future geological repository for spent nuclear fuel are given as relevant examples. This includes radiation‐induced dissolution of spent nuclear fuel in contact with groundwater, radiation‐induced corrosion of copper, and radiation‐induced alterations of bentonite clay. Current knowledge gaps in these areas are highlighted.

Meta-studtite stability in aqueous solutions. Impact of HCO3−, H2O2 and ionizing radiation on dissolution and speciation

“…In the event of a complete barrier failure in the repository, groundwater will be in contact with spent nuclear fuel. 6,7 This would provide the conditions necessary for spreading radioactivity to the biosphere. Fortunately, the UO 2 -matrix has very low solubility in reducing groundwaters that are typically present in many potential repository sites.…”

Surface Reactions of H2O2, H2, and O2 in Aqueous Systems Containing ZrO2

“…The surfaces in contact with water are usually oxides or metals covered with an oxide layer. Hence, radiation-induced processes at the interface between water and a solid oxide would appear to be crucial. − Nevertheless, very little is known about these processes.…”

Gamma radiation induces hydrogen absorption by copper in water

“…As for the other barrier materials, studies of processes that have potential impact on the long-term integrity of the copper layer have been conducted both in laboratories and in the field under repository conditions9. A rather unique feature of the copper used in spent nuclear fuel canisters is that it will be exposed to ionizing radiation1011121314. Because of this it is of vital importance to elucidate the effects of ionizing radiation on copper and on the interface between copper and surrounding matter.…”