The method of research nuclear installation conversion at the decommissioning stage

Abstract

The article examines the problem of forming scientific and technical programs for the conversion of research nuclear installations at the decommissioning stage, which arose in the aspect of justifying the possibility of extending the designated service life of all existing research nuclear reactors in Russia. To solve this problem, a methodology is proposed, which includes an information model and a process description of the necessary step-by-step actions, as well as a set of appendices in the form of documents justifying the most optimal ways to form a project for managing the quality of nuclear reactor conversion processes in relation to special life cycle conditions of specific nuclear reactors. The general view of the methodology is described: principles and methods of construction, structure. An example of the application of this technique in the conversion of the Hydra salt solution pulsed research reactor for the decommissioning stage is given. The purpose of the conversion of the Hydra reactor is to extend the designated service life by replacing non-repairable equipment ­ the vessel. The main criteria for justifying the residual life of the housing are formulated, which are the presence of a safety margin of the housing material, taking into account the accumulated fluence on more vulnerable areas and the justification of the integrity and tightness of the housing. For clarity, the conceptual information model of the methodology for justifying the safety of the process of replacing the Hydra reactor vessel is presented in the form of an Ishikawa diagram. The methodology represents a series of sequential scientific and technical activities, research and a finite number of step-by-step actions to achieve the final goal – extending the service life. The stages of the methodology for justifying the safety of replacing the Hydra reactor vessel are described, such as «clarification of initial data», «performing computational studies and laboratory experiments», «clarification of the requirements of methodological documentation» and «formation of a work plan» and «registration of licensing documents for operation».