Steam Generator Management at Ontario Hydro Nuclear Stations

Abstract

Managing ageing steam generators involves costly decisions for the utility, both in terms of the cost of the maintenance activities and in terms of having the unit shutdown and consequent power loss while performing these activities. The benefits of these activities are seldom guaranteed and are sometimes very intangible. For nuclear utilities the most pertinent questions that arise are have we identified all the problem(s), can we predict the risk due to these problems? Can we implement corrective and preventive activities to manage the problem and what is the optimum timing of implementation? Is the money spent worthwhile, i.e. has it given us a return in production and safety? Can we avoid surprises? How can we tangibly measure success? This paper touches briefly on all the questions mentioned above but it mainly addresses the last question: "how can we tangibly measure success?" by using several success indicators proposed by EPRI and by applying them to actual Ontario Hydro experience. The appropriateness of these success indicators as the means to assess the success of these programs, to feed back the results, and to enhance or revise the programs will be discussed.