APPLICATION OF PLASMA ARC CUTTING TECHNOLOGY IN DISMANTLING OF LARGE METAL COMPONENTS IN CONTAINMENT BUILDING

The decommissioning of nuclear reactor is a challenge to the sustainable development of nuclear energy. One of the most challenging tasks in reactor decommissioning is the dismantling and segmentation of radioactive large metal components in the containment building. A variety of cutting technologies have been developed for the special purpose. This paper is focused on the underwater plasma arc cutting technology and its potential applications. The characteristics of large metal components in nuclear containment building were summarized. The matters needing attention in the process of dismantling and segmentation were analyzed as well. The technical principle of plasma arc cutting was briefly introduced, and the selection of the key operational parameters are discussed, such as the types of gas and electrode materials. Cutting noise, arc light, and smoke will be efficiently reduced by underwater cutting. More importantly, underwater cutting can reduce the radiation dose to the occupational staff and optimize the radioactive waste management. A comparative evaluation was conducted among underwater plasma arc, arc saw and wire saw cutting. In the last part, a hypothetical scenario taking a steam generator as an example for dismantling is proposed and analyzed. The differences between the plasma arc cutting and the arc saw cutting were compared in terms of cutting time and the amount of secondary waste generation. In this paper, the underwater plasma arc cutting was comprehensively analyzed and discussed to validate the technology in the decommissioning of large metal components in the containment building. Some concerns for industrial application were revealed.