Current State and Prospects of Handling Graphite from Uranium-graphite Reactors

The aim of the study is to collect information on the current state with graphite from uranium-graphite reactors worldwide. Technical, organizational, economic, and social aspects of this issue are examined. Publications on the most promising graphite handling methods were studied, both in terms of determining the graphite radiation and mechanical characteristics and in terms of its further processing. Publications reflecting factors strongly influencing the investigated methodologies in the contemporary Western society, such as public opinion, economics, and the safety of all processes, have been selected. The article compiles and analyzes information on the current state of most components of the radioactive graphite handling process – its classification, dismantling methods, processing and packaging methods, and locations for final disposal. Statistics on the volumes and the current state of graphite in all countries in which there are such reactors is generalized, and current regulations and government-approved methods for handling graphite in these countries are listed. Most of the currently proposed methods for determining the physical condition and radiation characteristics of graphite have been examined, along with its processing in terms of practical industrial-scale applications. Information on deep geological repositories worldwide has been analyzed, and available information on implemented projects for decommissioning uranium-graphite reactors has been reviewed. A new perspective on the influence of the potential release of the most significant radionuclide in reactor graphite - 14С on its natural abundance in the natural environment is considered. The costs of the so-called "base" and "carbon capture and sequestration" methods in the United Kingdom along with the burial payment rates for deep geological repositories for intermediate- and high-level radioactive waste in Russia have been compared with each other. The conclusion is drawn that currently there are no universal and turnkey solutions for safe and economically feasible methods for complete dismantling and disposal of reactor graphite. On the other hand, the accomplished study made it possible to identify perhaps those specific lines in which the future research and calculations should only be conducted.