Induced nuclear reactions: processes – systems – and elements – Fission reactor material treatment – Impurity removal
Patent
1989-10-05
1992-01-07
Wasil, Daniel D.
Induced nuclear reactions: processes, systems, and elements
Fission reactor material treatment
Impurity removal
976DIG378, G21C 900
Patent
active
050789600
DESCRIPTION:
BRIEF SUMMARY
BACKGROUND OF THE INVENTION
The invention relates generically to a device for relieving pressure during a failure in the containment of a nuclear power station comprising a pressurized water reactor or boiling water reactor, the stream of compressed air from the containment being filtered and discharged to the atmosphere, the device comprising a filter unit for filtering off radioactively contaminated substances entrained in the stream of compressed air, and duct systems and fittings connecting the filter elements of the filter unit. As is known, the containment of a nuclear power station is a building designed to safety regulations and surrounding the reactor vessel and consequently the reactor core. In the invention, the term "filter unit" denotes the functional combination of a number of filter elements, even if serving widely different purposes. In the invention, a "duct system" can comprise a single duct or number of ducts connected by fittings.
The generic device is known from the recommendations of the Reactor Safety Commission. It is included among the measures for protection against failures inside the station and serves to reduce the remaining risk, more particularly during a meltdown. In the known device, the filter unit and all the elements thereof are disposed outside the containment. This necessitates special, expensive buildings for the filter unit, particularly since the filter elements absorb radioactive substances during use and accordingly have to be screened. There are also functional problems. Unless further modifications are made to the building in which the filter unit is located, the filter elements will be in an environment at a temperature considerably lower than the temperature in the containment. A disturbing amount of radioactively contaminated condensate therefore collects in the filter elements. The condensate lowers the efficiency of the filter elements.
It is the object of the invention to improve the generic device so that the buildings can be considerably less expensive and so that the amount of condensate collecting in the filter elements can be reduced, so as not to impair the efficiency of the filter elements through a disturbing accumulation of condensate.
SUMMARY OF THE INVENTION
Therefore according to the invention, at least one subunit of the filter unit is located inside the containment, and at least one duct system for discharging the stream of filtered compressed air is connected to the subunit and extends through the wall of the containment and can be closed by fittings which can be actuated in the event of failure. In the embodiment wherein the filter unit is equipped with aerosol filter elements only, the entire filter unit is located in the containment. The invention also has considerable advantage if the filter unit is formed of subunits serving various functions and comprises an aerosol filter subunit and a molecular-sieve subunit for iodine filtration. In this case, the aerosol filter subunit is disposed inside the containment and the molecular-sieve unit is connected outside the containment via a duct system comprising a reducing valve and actuatable fittings to the duct system for discharging the stream of compressed air.
Optionally, the molecular-sieve subunit is located in an existing building for auxiliary equipment. In the embodiment in which the filter unit comprises an aerosol filter subunit and a molecular-sieve subunit for iodine filtration, preferably both of these subunit are disposed inside the containment and the molecular-sieve subunit is connected via a duct system, a reducing valve and actuatable fittings to the duct system for discharging the stream of compressed air.
Advantages of the invention are that the building construction is simplified and operation is greatly improved. A simplified building construction arises because the containment, which is present in any case, serves the additional purpose, of holding the filter units, which does not require alterations to the building but insures an improved operation. In comparison wit
REFERENCES:
patent: 4057464 (1977-11-01), Mair et al.
patent: 4088737 (1978-05-01), Thomas et al.
patent: 4151689 (1979-05-01), Schabert
patent: 4610840 (1986-09-01), Leach
patent: 4913850 (1990-04-01), Puppe et al.
Nuclear Technology, vol. 72, Mar. 1986, Braun et al., pp. 268-290.
Berg Diethart
Reddehase Claus-Gert
Wolf Manfred
Dubno Herbert
RWE Energie Aktiengesellschaft
Wasil Daniel D.
Wilford Andrew M.
LandOfFree
Device for relieving the pressure in the containment of a nuclea does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Device for relieving the pressure in the containment of a nuclea, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Device for relieving the pressure in the containment of a nuclea will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-820392