Research on improvement of marine nuclear reactors and future perspective

The features when atomic energy is utilized on the sea are that the fuel cost is low, accordingly it is suitable to the power sources of large output, that the volume and weight of fuel are small, accordingly it is suitable to the continuous operation for a long period without refueling, and that oxygen is not required for the burning, accordingly it is suitable to undersea power sources. In USSR, four nuclear icebreakers have been in use, and four more are under construction. A nuclear LASH ship has been operated, and one more is under construction. As the other fields than sea transportation, an electricity generation barge MH-1A of USA used as the auxiliary power source for the Panama Canal and a research submarine NR-1 of USA have been in practical use. With the advance of ocean development in future, the creation of needs such as deep sea power stations, deep sea research ships and deep sea work ships is expected. Marine nuclear reactor technology was begun in the form of the nuclearization of merchant ships, and Savannah of USA, Otto Hahn of West Germany and Mutsu of Japan were built. The marine nuclear reactors built so far and of which the conceptual design was carried out are shown. The improvement of marine reactors is the reduction of size and weight, the simplification of the system, the adoption of self pressurization and self compensation and so on. The research on the improvement in Japan Atomic Energy Research Institute is reported. (Kako, I.)