Technologies Used for D&D of the A-1 NPP in Slovakia and Their Comparison With Advanced Worldwide Approaches

Abstract

This paper deals with technologies used for decommissioning and decontamination of the A-1 Nuclear Power Plant in Slovakia and their comparison with advanced worldwide approaches. Present status and main results in the field of D&D of this first Czechoslovak NPP A-1 at Jaslovské Bohunice are described. NPP A-1 has one unit with reactor cooled by CO2 and moderated by heavy water. Plant was in operation from 1972 to 1977 and its final shutdown and closure were done due to relatively serious accident. The A-1 NPP Decommissioning Project – I. phase is performed at the present time and represents the most important project of NPP decommissioning in Central Europe. The main goal of the project is to achieve radiologically safe status of the NPP. It includes following activities: • conditioning, storage and disposal of liquid radioactive waste, solid and metallic radioactive waste, sludge and sorbents, • development, manufacture and verification of advanced methodologies and technologies for D&D of nuclear facilities, • decontamination of specified equipment and structures to reduce free activity, • technical support and preparation of following phases within the A-1 NPP overall decommissioning process. The project should give the complex solution of problems related to decommissioning and decontamination of NPPs in Slovakia. Verified methodology and technology should be used as a generic approach for decommissioning of the V-1, V-2 (Jaslovské Bohunice) and Mochovce Nuclear Power Plants as well as the other European NPPs with WWER reactors. Significant part of paper deals with following issues within D&D of the A-1 NPP: • computer aided technologies, • decontamination, • dismantling, demolishing and remote handling manipulators, • dosimetry measurements within D&D, • radioactive waste management. This paper also includes basic comparison with advanced worldwide approaches to decommissioning and decontamination mainly in USA, Japan and West Europe and the recommendations are done when it is possible. The comparison shows that trends in the field of D&D in the Slovak Republic are compatible and comparable with the most significant world trends. It is noted that some sorts of D&D technologies like for example telerobotic systems developed in the world are at the relatively higher technical level. Decommissioning technologies in Slovakia should be permanently improved on the base of experiences from home and abroad industry and from the real operation. It is supposed that after short time could be achieved technical level comparable with the best D&D robots and manipulators. A basic strategy of NPP decommissioning in the Slovak Republic is regulated by standards, which are in accordance with recommendations of international bodies like the International Atomic Energy Agency, European Commission, U.S. Nuclear Regulatory Commission, OECD Nuclear Energy Agency etc. In the field of NPP D&D the Slovak Republic co-operates with many international organizations and also with main active countries in D&D like Germany, France, Belgium, Great Britain, USA, Japan, Russian Federation, Hungary, Poland and Czech Republic. Intensive international co-operation at all levels has already been established at the present time.