Reliability and safety analysis for systems of fusion device

Abstract

Fusion energy or thermonuclear power is a promising, literally endless source of energy. Development of fusion power is still under investigation and experimental phase, and a number of fusion devices are under construction in Europe. Since fusion energy is innovative and fusion devices contain unique and expensive equipment, an issue of their reliability is very important from their efficiency perspective.A Reliability, Availability, Maintainability, Inspectability (RAMI) analysis is being performed or is going to be performed in the nearest future for such fusion devices as ITER and DEMO in order to ensure reliable and efficient operation for experiments (e.g., in ITER) or for energy production purposes (e.g., in DEMO). On the other hand, rich experience of the reliability and Probabilistic Safety Analysis (PSA) exists in nuclear industry for fission power plants and other nuclear installations.In this paper, the Wendelstein 7-X (W7-X) device is mainly considered. This stellarator device is in commissioning stage in the Max-Planck-Institut für Plasmaphysik, Greifswald, Germany (IPP). In the frame of cooperation between the IPP and the Lithuanian Energy Institute (LEI) under the European Fusion Development Agreement a pilot project of a reliability analysis of the W7-X systems was performed with a purpose to adopt Nuclear Power Plant (NPP) PSA experience for fusion device systems. During the project reliability and safety (risk) analysis of a Divertor Target Cooling Circuit, which is an important system for permanent and reliable operation of in-vessel components of the W7-X, was performed.Application of reliability and safety analysis for systems of fusion device enable to recommend and prioritize availability improvement measures for such systems and thus increase efficiency of fusion device. The methods and models described in this paper could be easily adopted for other systems of various fusion devices.