Calculation of the cost of Generating Power in a Fast Reactor by the Discounting Method

A method of calculating the discounted cost of fuel cycles, using a computer, was presented during the 2nd Nuclear Meeting of the Forum Atómico Español held in Madrid during 27-28 October 1966. This method had been developed for optimization studies in relation to a 1000-MW(e) fast reactor under the ''Fast Reactors'' partnership agreement concluded between Euratom and the Belgian Government. The object of the paper is to describe how the method is applied and to analyse the initial results obtained with it. The calculational code, for use with an IBM 360 computer, consists of two parts. In the first part, the reactor characteristics necessary for the economic computations are determined; these consist essentially of the initial and final composition of the fuel (isotopic composition, plutonium content, proportion of inert material, fuel weight) and the time during which the fuel remains in the reactor. These characteristics are computed for each zone of the core, and of the axial and radial breeding blankets. In the second part of the code, the fuel cycle characteristics are first calculated: doubling time and various factors required for feasibility studies (loading and unloading factors, inventory factors in terms of natural uranium or 239Pu equivalent). The various specific costs are then determined by means of sub-routines. The discounting calculations are performed for each reactor zone and combined into two separate groups: costs discounted to the time of reactor start-up and costs discounted to shut-down. Two approaches are then possible, depending on whether the fissile material is purchased or leased from a national or international organization (this in turn depends on whether private ownership of fissile materials is permitted). The costs, expressed in kWh, are then grouped by zone and by type of operation (transport, manufacture, etc.), and sub-divided into fixed and variable costs, and operating and capital costs. The method has been applied to the German Na-1 reactor, and the results are extremely interesting. The cost breakdown shows the Importance of capital costs in the fuel cycle of a fast reactor. The Influence of various technical and economic parameters is brought out; for example, bum-up (the effect of which can no longer be represented by a simple hyperbola), loading frequency, the rate used for discounting and the price of plutonium. (author)