Reliability Analysis of a Central Computer System Power Supply

Abstract

The Chalk River Nuclear Laboratories (CRNL) central computer facility provides mainframe computer service to the various functional groups on site. About 1500 local and remotely located people use this service for scientific research activities, inventory control, accounting and word processing and data transmission links off site.

The computer facility suffers from occasional unscheduled interruptions in service. This causes inconvenience to users and reduces their productivity. The unavailability of the computer causes activities dependent on it to be postponed or cancelled. These consequences can be minimized by reducing the frequency and duration of interruptions.

One major source of unscheduled computer service interruptions has been traced to power disturbances. This includes both short-duration power disturbances (< 5 s), and longer duration (> 5 s) power outages. This study is an analysis of the power-line disturbances at CRNL and their correlation to interruptions in computer service. The adequacy of the protection equipment for power-line disturbance related computer interruptions is also assessed.