Patent Number: 039727726
Section: summary

The invention of the instant application relates to a steam power plant for nuclear power stations having pressurized water reactors wherein quantities of blowdown water, which are produced due to an accumulation of existing and continually developing impurities in the water circulation system, are to be removed. Generally the quantities of blowdown water used to be brought initially to a relatively low pressure in an expansion or blowdown tank, thereafter the blowdown was cooled to temperatures of 40.degree.C, for example, through a brine cooler, and the blowdown would then be discarded. Considerable water losses can be produced thereby. Another disadvantage is that when there are leakages between the primary and the secondary circulatory systems, the blowdown water must be further treated in the purification or preparation plant for radioactive waste waters. If the capacity of the preparation plant is thereby exceeded, the power station must be shut-down. It is accordingly an object of the invention to provide steam power plant for nuclear power stations having pressurized water reactors which avoids the foregoing disadvantages of the heretofore known plants of this general type. With the foregoing and other objects in view, there is provided, in accordance with the invention, in steam power plant for nuclear power stations having pressurized water reactors and including a water circulation system from which quantities of blowdown water produced due to an accumulation of existing and continually developing impurities therein are removable through a blowdown line, a purifying device connected in the blowdown line and comprising an electromagnetic filter, a mixed bed filter connected thereto, and means for returning to the water circulation system at least part of the water contained in the quantities of blowdown water. If the blowdown water is now cleaned by the electro-magnetic filters or by filters, operating in a similar manner as well as by mixed bed or powdered resin filters, to such an extent that it is returnable to the circulatory system, the need for additional water will be considerably reduced. When leakages occur between the primary and the secondary cycle, the non-dissolved and dissolved activity carriers entrained thereby, can be removed from the water so that the operation of the plant can be maintained. Only the much smaller amounts of rinsing and regenerating waters that accumulate must be further treated in the preparation plant for radio-active waste waters. Although the invention is illustrated and described herein as embodied in steam power plant for nuclear power stations having pressurized water reactors, it is nevertheless not intended to be limited to the details shown, since various modifications and structural changes may be made therein without departing from the spirit of the invention and within the scope and range of equivalents of the claims. The construction and method of operation of the invention, however, together with additional objects and advantages thereof will be best understood from the following description of specific embodiments when read in connection with the single FIGURE of the drawing which is a schematic view of the blowdown water purifying device for the circulatory system of a steam power plant for a nuclear power station having a pressurized water reactor, in accordance with the invention.