Availability improvement of ITER blanket remote handling system

Highlights: •Characteristics of the remote-handling systems for fusion reactors and methods to improve their availability were studied. •It was concluded that preventive maintenance is a powerful method to improve availability of the remote-handling systems. •A procedure to optimise parameters of preventive maintenance was proposed. •By applying the procedure to the ITER Blanket Remote Handling System, effectiveness of the procedure was shown. -- Abstract: Availability is of the utmost importance in remote-handling systems for fusion reactors. A number of factors are specific to this application in terms of availability. After investigating those factors, we have concluded that preventive maintenance is the best method to universally increase remote handling system availability. As such, we created a procedure through reliability block diagram analysis that takes availability, completion probability, and number of failures into account to determine the parameters for preventive maintenance and determine the quantity of spare parts required. By applying our procedure preventive maintenance increased the availability of the ITER blanket remote handling system from 46% to 88%, while the expected number of total failures was reduced from 5.5 to 1.6. Completion probability remained at virtually 100%, thus demonstrating that our procedure can improve system availability.