Nosovs'kyj A. Scientific and Technical Bases for Nuclear Power Plants with RBMK Reactors Decommissioning

The work deals with the problems of nuclear power plants' units decommissioning. This is a new activity for the nuclear industry of Ukraine, which expects specific scientific knowledge and work-studies. Summary and the optimal option of NPP worked-out units decommissioning were presented and the decommissioning concept was developed in the doctoral thesis. Chernobyl NPP Unit 1 was considered as an example of preparation, planning, and implementation of comprehensive engineering and radiological surveys at the shutdown stage. The calculations of radiation characteristics have been performed for RBMK-1000 reactor constructions. Taking into account Unit Shelter, the Exclusion Zone, and the presence of other aftermaths of accidents and radiation incidents at the Chornobyl site the ChNPP units decommissioning characteristic features were analyzed. A collection of methods for determining radiation characteristics of equipment and materials' activity based on the results of spectrometric measurements in the course of radiological research was developed. Computer program for informational support of decommissioning activities was generated and methodological recommendations on safe implementation of activities at the stage of power unit decommissioning were developed. Results of the thesis were applied at Chornobyl NPP during planning and preparing the reference and operational documentation, carrying out practical activities aimed at power units decommissioning and Unit Shelter transformation into an ecologically safe system.