Integrated Maintenance Program (IMP)

Abstract

Approaches to the maintenance of nuclear power plants have undergone significant change in the past several decades. The traditional breakdown approach has been displaced by preventive (calendar-based) maintenance and more recently, by condition-based maintenance (CBM). This is largely driven by the fact that traditional maintenance programs, derived primarily from equipment vendor recommendations, are generally unsuccessful in controlling maintenance costs or equipment failures. Many advances in the maintenance field have taken place since the maintenance plans for Ontario Hydro's nuclear plants were initially established. Ontario Hydro nuclear plant operating costs can be substantially reduced and Incapability Factor improved with the application of modern maintenance processes and tools. Pickering is designated as the lead station for IMP. Of immediate concern is the fact that Pickering Nuclear Division has been experiencing a significant backlog of Operating Preventive Maintenance Callups1. This backlog, over 2000, is unacceptable to both station management and the nuclear regulator, the Atomic Energy Control Board. In addition there are over 500 callups in various stages of revision (in hyperspace) without an adequate control nor reporting system to manage their completion. There is also considerable confusion about the classification of licensing callups, e.g. callups which are mandatory as a result of legal requirements. Furthermore the ineffectiveness of the Preventive Maintenance (PM) has been the subject of peer audits and Atomic Energy Control Board (AECB) findings over the past several years. The current preventive maintenance ratio PM2 /(PM+CM3) at Pickering ND is less than 20%, due to the current high load of equipment breakdown. This past summer, an Independent Integrated Performance Assessment (IIPA) review at Ontario Hydro confirmed these concerns. Over the past several years, Ontario Hydro nuclear staff have evaluated several programs to improve the station's maintenance effectiveness and reduce maintenance costs including RCM4, callup overhauls, analysis of equipment and system failure history to name a few. It has become apparent that there is no single Do-All maintenance strategy. What is needed is an integrated program combining the benefits of a variety of problem-specific strategies. Such a program should address both the short term and long term station requirements. The impact of the Integrated Maintenance Program (IMP) is expected to be high. In the short term, IMP will upgrade the call-up management system to provide accurate classification, effective monitoring and reporting, and develop a documented rationale (PMO) for each Preventive Maintenance task. To the greatest extent possible, IMP will utilize on-condition (predictive) maintenance and result in the elimination or replacement of many obsolete or ineffective preventive maintenance call-ups. The IMP described in this paper, will improve maintenance effectiveness, equipment reliability and have cost benefits to Ontario Hydro. In doing so it will reduce the cost of maintenance and improve system availability and reliability.