[en] 16 nuclear power plants are in commercial operation in Japan, and nuclear power generation holds the most important position among various substitute energies. Hereafter also, it is expected that the construction of nuclear power stations will continue because other advantageous energy sources are not found. In this paper, the outline of the pumps used for BWR plants is described. Nuclear power stations tend to be large scale to reduce the construction cost per unit power output, therefore the pumps used are those of large capacity. The conditions to be taken in consideration are high temperature, high pressure, radioactive fluids, high reliability, hydrodynamic performances, aseismatic design, relevant laws and regulations, and quality assurance. Pumps are used for reactor recirculation system, control rod driving hydraulic system, boric acid solution injecting system, reactor coolant purifying system, fuel pool cooling and purifying system, residual heat removing system, low pressure and high pressure core spraying systems, and reactor isolation cooling system, for condensate, feed water, drain and circulating water systems of turbines, for fresh water, sea water, make-up water and fire fighting services, and for radioactive waste treating system. The problems of the pumps used for nuclear power stations are described, for example, the requirement of high reliability, the measures to radioactivity and the aseismatic design. (Kako, I.)

[en] Purpose: At the time of starting from the low-temperature condition in a device for handling a high temperature fluid, to evade an abrupt temperature rise of the device and to increase slowly the temperature thereof. Constitution: Bypass pipes are provided at the suction side of a circulating pump and at the outlet side of a regenerated heat exchanger, and valves are provided in parallel to the branched pipes. The downstream sides of the valves are converged and connected to the reactor water supply source. At the time of starting, a closed loop is functioned to a circulation system consisting of circulation pump-regenerated heat exchanger-non-regenerated heat exchanger-filtration desalting device-regenerated heat exchanger-circulation pump, and circulation water of the closed loop is caused to gradually flow to the reactor under surveilance of a thermometer. High temperature water of the reactor is caused gradually to flow into the closed loop, and the temperature of the closed loop is slowly raised. (Aizawa, K.)