Some aspects of the decommissioning of nuclear power plants

Abstract

The major factors influencing the choice of a national concept for the decommissioning of nuclear power plants are examined. The operating lifetimes of power generating units with nuclear reactors of various types (VVÉR-1000, VVÉR-440, RBMK-1000, ÉGP-6, and BN-600) are analyzed. The basic approaches to decommissioning Russian nuclear power plants and the treatment of radioactive waste and spent nuclear fuel are discussed. Major aspects of the ecological and radiation safety of personnel, surrounding populations, and the environment during decommissioning of nuclear installations are identified.The natural disaster in Japan on March 11, 2011 caused an accident at the Fukushima-1 nuclear power plant and has become a landmark in the history of worldwide nuclear power. Many countries with nuclear technologies, such as Germany, Belgium, Italy, Switzerland, etc., are now reexamining their plans for the use of nuclear power. This means that, if a political decision is made to cease operating power plants that have reached the end of their working lifetimes, there will be massive decommissioning of these plants.There are 439 power reactors in the world, of which half (218) are concentrated in three countries, the USA, Japan, and France. Nuclear power plants are operating in 29 out of a total of approximately 200 countries. Today, 30% (166) of the power generating units are more than 30 years old and will soon require decommissioning, while 83% are more than 20 years old.A brief digression on the history of the problem. The decommissioning of nuclear power plants is an inevitable part of their life cycle. According to the regulatory document OPB-88/97, the decommissioning of a nuclear power plant involves a series of steps following the removal of nuclear fuel to prevent use of the generator unit as an energy source and ensure the safety of personnel, local populations, and the environment [1].Decommissioning can be for the following reasons [2]: -completion of the planned service lifetime; -accidents, after which operation is impossible or inappropriate;-changes in reliability and operational safety specifications which cannot or should not be satisfied with the existing design; -economic unsuitability for further operation; and, -the political situation in the country. All of these factors have already served as the reasons for decisions to decommission nuclear power plants. Thus, the first and second units at the Novovoronezhskaya nuclear power plant (NPP) were finally halted after 20 years of work; the first and second units of the Beloyarskaya NPP were closed because it was uneconomical to update them following damage to the equipment; unit A-1 of the Bohunice NPP was decommissioned after an accident; the Armenian NPP was closed because of changes in safety specifications for NPPs; all plants with gas-graphite reactors in France were stopped because they were uncompetitive with water-water power units; and, the Ignalina and Nord NPPs were closed for political reasons.Worldwide practice has shown that decommissioning ...