TFTR CAMAC power supplies reliability

Since the life expectancy of the Tokamak Fusion Test Reactor (TFTR) has been extended into the early 1990s, the issues of worn-out equipment, when to refurbish/replace, and the costs associated with these decisions must be faced. The management of the maintenance of the TFTR Central Instrumentation Control and Data Acquisition System (CICADA) power supplies within the CAMAC network is a case study of a set of systems to monitor the reliability, costs, and results of action of repairable systems. The CAMAC network is composed of approximately 500 racks, each with its own power supply. By using a simple reliability estimator on a coarse time interval in conjunction with determining the root cause of individual failures, a cost-effective repair and maintenance program has been realized. The estimator, some of the specific causes for recurring failures and steps toward correcting them, and the subsequent effects on estimator reliability are described. By extending this program, the continued viability of CAMAC power supplies can be assessed into the future, predicting wear-out and developing cost-effective refurbishment/replacement policies