Patent Number: 048636770
Section: description

Referring now to the figures of the drawings in detail and first, particularly, to FIG. 1 thereof, there is seen a containment 1 of a pressurized water reactor, which is conventionally constructed in the form of a steel sphere. The containment 1 encloses the primary system of a pressurized water reactor for 1300 MW.sub.e, for instance. This system also includes non-illustrated steam generators, with which a thermal output of approximately 4000 MW in the form of steam are supplied to an engine room that is located beside the containment. The containment 1 is surrounded by a thick-walled concrete building, so that a second containment which is not dealt with herein, is also provided, as in the case of the pressurized water reactor in German Patent DE-PS 26 34 356, corresponding to U.S. Patent No. 4,151,689. An outlet line 3 protrudes into the interior 2 of the containment 1. A mist collector 4 is provided on the inner end of the outlet line 3. The line 3 forms an outlet opening. In the event of a malfunction in which a negative pressure is provided, the medium effecting the negative pressure, that is, steam and gas, can be carried away through the outlet opening before the bursting pressure of the containment 1 is attained. The line 3 leads to a filter and blow-off configuration, generally identified by reference numeral 5. The structure of the filter and blow-off configuration will be described in further detail below, referring to FIGS. 2-5. A pressure maintenance and limiting device, which is symbolized by a safety valve 6 in FIG. 1, is also connected to the line 3. In practice, the safety valve 6 may, for instance, be formed of two safety valves which are connected in series and are actuated by a special or individual medium, in order to limit the pressure in the containment to a value of 6 bar, for example. Two motor-actuated or manual shutoff valves 8 and 9 are connected parallel to line segments 7 having the safety valve 6 and are connected in series or through a separate line to the configuration 5. In an alternative structure which is shown in broken lines in FIG. 1, the line 3 can be provided with a bursting diaphragm 10, which has a response pressure of 7 bar, for example. FIG. 2 shows that the line 3 leads into a container 12 that forms a substantial part of the filter and blow-off configuration 5. The lower portion of the container 12 encloses a volume 13 of washing fluid, especially water, the surface of which is indicated at reference numeral 14. The surface of the water is located at a level approximately one-half to three-quarters of the way up the container 12. A Venturi scrubber 15 in the form of a jet pump is disposed in the water volume 13. The Venturi scrubber 15 is located at least 1 meter below the surface of the water. An intake side 17 of the Venturi scrubber 15 can be connected to the line 3 through a further jet pump 18, with which the outlet medium leaving the containment 1 can be reinforced with water, as indicated by an arrow 19. Alternatively, the water 13 is aspirated directly, as indicated by an arrow 21. In order to reduce the temperature of the outlet medium leaving the containment 1, the Venturi scrubber 15 can be preceded by a throttle restriction 22 and a jet pump 23, which operates as a heat remover and adds water as indicated by an arrow 24. The result is saturated steam at a lower temperature, which prevents overloading of the Venturi scrubber 15. Instead of the jet pump 23, another type of heat exchanger could also be used. The outlet of the Venturi scrubber 15 leads into a gas space 27 above the surface 14 of the water. An outlet line 29 that begins at a fluid collector or trap 28, is connected to the gas space 27 and leads into a stack 30. Liquid from the filter 28 flows through a liquid outlet 31 leading back into the volume 13 of water. The line 31 may be omitted if the filter 28 is disposed in the gas space 27 in the container 12. The container 12 can also have a cooling device, such as a cooling coil for re-cooling the washing fluid 13, and a collecting pan which prevents a release of the washing fluid in the event of leakage. The end of the outlet line 29 facing toward the stack can be provided with a mixing nozzle 32. This primarily takes the form of a jet pump, with which ambient air is aspirated for diluting and cooling purposes. With the Venturi scrubber 15, effective aerosol moistening and iodine absorption are attained utilizing the pressure which is already present in the containment 1. Accordingly, the retention of activity carriers is possible, with substantially less space being required that in the case of the conventional use of a mound of soil. In the embodiment of FIG. 3, a mist collector 28 is located below the surface 14 of the water. The mist collector 28 is acted upon directly by the Venturi scrubber 15. The gas outlet 34 of the mist collector 28 leads to a gas distributor, 35, with which gas cleaned in the Venturi scrubber 15 is distributed uniformly over the volume 13 of the liquid. The outlet of the container 12 leads into a fiber mist collector 37, to which the line 29 is connected. The line 29 also leads through the mixing nozzle 32 into the stack 30. The moisture accumulating in the filter 37 is returned to the container 12 through a line 38. In the embodiment of FIG. 4, the gas volume 27 is divided into two zones by a partition 40 that protrudes below the surface 14 of the liquid. Two Venturi scrubbers 15' and 15" are disposed in the volume of water 13, each on a respective side of the partition 40. A throttle restriction 41 connects the scrubbers in parallel to the line 3. The Venturi scrubbers 15' and 15" are mounted at different heights below the surface 14 of the liquid. As a result, in partial-load operation the Venturi scrubber 15' that is at a lower level is more or less put out of operation, because of the higher liquid pressure. The Venturi scrubber 15" located at a higher level therefore operates under volumetrically optimized operating conditions. The two sides of the gas space 27 lead through mist collectors 28', 28" to the outlet line 29, which is provided with a high efficiency submicron particulate air filter 42 for further cleaning of the gases and for retaining aerosols. The submicron particulate filter 42 is preceded by a throttle 43 and followed by a mixing nozzle 32. In the embodiment of FIG. 5, the outlet line 29 includes not only the fiber mist collector 37, which is equivalent to that of the embodiment of FIG. 3, but also the throttle restriction 43 and the high efficiency submicron particulate filter 42 of the kind already shown in FIG. 4. The Venturi scrubber 15 feeds the gas distributor 35 through the mist collector 28. The foregoing is a description corresponding in substance to German Application P 36 37 795.3, dated Nov. 6, 1986, the International priority of which is being claimed for the instant application, and which is hereby made part of this application. Any material discrepancies between the foregoing specification and the aforementioned corresponding German application are to be resolved in favor of the latter.