Abstract: An improved method of selecting and planning the performance of various maintenance activities on a facility such as a nuclear power plant includes determining the net present value of a number of future net savings that are expected to result from performance of the maintenance activity at a given time, and selecting and planning the maintenance activities in a fashion that maximizes net present value. The method includes, for each of a number of components and a number of time periods, determining a change in the probability that a component will fail within a time period, with the change resulting from an assumption that a maintenance activity is performed. The change in probability is multiplied with the losses associated with a failure in order to determine a gross savings from which costs are subtracted to determine net savings.

Abstract: A shield panel for use in a nuclear reactor including a reactor vessel susceptible to embrittlement when bombarded with high energy neutrons and a nuclear reactor core mounted within the reactor vessel, the reactor vessel having a longitudinal axis and an inner surface surrounding the longitudinal axis, and the nuclear core emitting high energy neutrons which impinge on the inner surface of the reactor vessel. The shield panel includes a canister which contains a completely enclosed interior space and which is mountable between the inner surface of the reactor vessel and the nuclear core in a region wherein the reactor vessel is susceptible to a higher rate of embrittlement than the remaining portion of the vessel when bombarded with high energy neutrons emitted from the nuclear core, and a substance consisting essentially of a heavy metal and hydrogen filling the interior space of the canister.