[en] 'The development in the power reactor field', the Director General, Dr. Sigvard Eklund, told the opening session, 'is best demonstrated by the fact that since September 1962 eleven power reactors with a nominal power of 650 MW(e) have become critical. At present, 50 power reactors with a total nominal output of 2800 MW(e) are in operation in ten Member States. In addition, 35 more nuclear plants with an aggregate capacity of 6900 MW(e) are under construction, and should bring the nuclear capacity to the 10 000 MW mark by the end of 1968.' The Deputy Director General for Technical Operations, Mr. P. Balligand, said that the Conference on Operating Experience with Power Reactors, held in June 1963, had reviewed the information yielded by the twenty or so nuclear power stations already in operation, and had drawn extremely encouraging conclusions. The nuclear installations had given no trouble and the utilization factor had been extremely high - inmost cases above 90 percent. The reactors had proved safe and it had been possible to increase the rated capacity of a good number without major changes in the installations; it had also been possible to reduce considerably their cost per kW installed. The experts had expressed the view that existing types of reactor could operate economically alongside the first series of breeder generators for a considerable time. The future prospects of nuclear power plants were being viewed with increasing optimism. Rapid progress was being made in respect of fuel cycles, and the earlier estimates of the cost of producing nuclear power might be reduced in the current year by 10 per cent. The cost of fuel cycles was determined by a large number of variable factors, such as the price of uranium oxide, the fuel burn-up achieved, the cost of fabrication, processing, and the credit for plutonium; in estimating the total cost all these factors must be borne in mind. While the cost of uranium oxide, for example, might continue to be $6 per lb for a few years, it might be higher when the number of power plants under construction increased. Any increase in the price of uranium oxide might be offset by reactor improvements - for example, by changing the burn-up. Similarly, a reduction in the plutonium credit would probably result in greater efforts being made to develop breeder reactors using plutonium as fuel. Intermediate solutions between natural-uranium and enriched-uranium reactors, and between breeder and non-breeder reactors, were also being studied, as were the long-term market prospects for the various nuclear fuels, depending on the various possible fuel cycles that might be employed.