Abstract: A passive natural circulation cooling system according to the present invention can comprise: a passive condensation tank formed to accommodate cooling water; and a condensate water recirculation device provided at the inner part or upper part of the passive condensation tank, and condensing the cooling water such that the cooling water circulates inside the passive condensation tank. The condense water recirculation device can include: a duct extending upwards from the upper part of the passive condensation tank; and a plurality of partition plates provided inside the passive condensation tank or the duct.

Abstract: A system for the abatement of noxious emissions from an industrial or nuclear power plant or the like in the event of accident includes a structure for impermeabilization of the ground, which extends at least in an annular area that surrounds the plant, a plurality of water-sprinkling towers, which are arranged around the plant and sprinkle water in the atmosphere, preferably added with chemical and/or biological and/or mineral substances, and a peripheral collection structure, configured for receiving water withheld by the impermeabilization structure.

Abstract: A system and a method for a passive containment vent system for a Boiling Water Reactor (BWR). The system is capable of venting and scrubbing a gaseous discharge from the primary containment of the BWR over a prolonged period of time leading up to or following a serious plant accident, without the need for monitoring by on-site plant personnel. External electrical power is not required (following initial activation of the system) in order to operate the containment vent system. The system may protect the integrity of primary containment during and following the serious plant accident.

Abstract: A system and a method for capturing gaseous, particulate and liquid radioactive material released from primary containment of a Light Water Reactor (LWR) during severe accident conditions. The system includes a below-grade media area, connected to a reactor pressure vessel (RPV) and portions of primary containment, providing varying levels of adsorption/absorption of the radioactive material. The media area is located on-site to offer a passive, self-regulating structure for stabilizing a nuclear reactor. The capture system provides for liquid drainage and gaseous venting of the radioactive material, and a treatment capable of treating the media following stabilization of the reactor.

Abstract: A nuclear plant has a containment shell and a pressure relief pipe connected thereto in which a blowing device and a Venturi washer placed in a container with a washing liquid are connected in series. Even the finest particles or aerosols carried by air are held in the Venturi washer with a very high degree of reliability and the release thereof in environment is excluded in a particularly reliable manner in the case of decompression even associated with seal failures. For this purpose, the size of the blowing device and the Venturi washer are selected in such a way that during the operation of the blowing device a flow rate of liquid in the Venturi washer flowing to the decompressing pipe is higher than 130 m/sec, preferably higher than 180 m/sec.

Abstract: In accordance with the present invention, there is provided a strainer system for use in a nuclear sump. The strainer system of the present invention includes at least one primary strainer module which defines a primary strainer/filter surface. In the strainer system, the primary strainer surface of the primary strainer module has a debris interceptor which is cooperatively engaged thereto, and may be outfitted with one or more pressure released or activated membranes. In a loss of coolant accident, the debris interceptor, alone or in combination with the pressure activated membrane(s), is adapted to reduce the differential pressure experienced across the strainer system in nuclear power plants with medium to high fiber loads.

Abstract: A post-accident fission product removal system may include an air mover, a filter assembly, and/or an ionization chamber. The air mover may be configured to move contaminated air through the filter assembly to produce filtered air. The ionization chamber may be connected to the filter assembly. The ionization chamber may include an anode and a cathode. The ionization chamber may be configured to receive the filtered air from the filter assembly and to ionize and capture radioisotopes from the filtered air to produce clean air.

Abstract: A nuclear installation has a reactor containment which is connected to a pressure relief line. A Venturi scrubber, which is arranged in a vessel containing a washing liquid, and a throttle device are connected in series in the pressure relief line. The novel system restrains, with particularly high reliability, fine air-transported activities or aerosols during decompression such that release thereof into the environment is practically impossible. The Venturi scrubber and the throttle device are dimensioned in such a way that, in the case of a critical drop in pressure of an air-vapor mixture flowing in the decompression line, a flow speed of said air-vapor mixture of more than 150 m/s, preferably more than 200 m/s, can be adjusted with respect to the throttle device in the Venturi scrubber.

Abstract: Pressurizer for a pressurized water nuclear power station, comprising an outer casing which delimits an inner space; a duct (11) which extends beneath the casing and which is capable of being tapped from the coolant system of the nuclear power station; a tap (18) which places the inner space of the casing in communication with the duct (11), this tap (18) being welded to the duct (11) by means of a weld seam (32); a sleeve (42) for protecting the weld seam (32), which sleeve is arranged inside the tap (18) and which has a lower peripheral edge (46) which is engaged in the duct (11), the sleeve (42) defining with the tap (18) and the duct (11) an annular space (74) which is capable of being filled with the primary liquid; wherein the annular space (74) is open along at least a portion of the lower peripheral edge (46) of the sleeve (42) and opens inside the duct (11).

Abstract: A decontamination system uses magnetic molecules having ferritin cores to selectively remove target contaminant ions from a solution. The magnetic molecules are based upon a ferritin protein structure and have a very small magnetic ferritin core and a selective ion exchange function attached to its surface. Various types of ion exchange functions can be attached to the magnetic molecules, each of which is designed to remove a specific contaminant such as radioactive ions. The ion exchange functions allow the magnetic molecules to selectively absorb the contaminant ions from a solution while being inert to other non-target ions. The magnetic properties of the magnetic molecule allow the magnetic molecules and the absorbed contaminant ions to be removed from solution by magnetic filtration.

Abstract: In a chemical decontamination method of chemically decontaminating radioactive nuclides from a metallic material, oxalic acid and hydrazine are injected as a reductive decontaminating agent into water that is in contact with the metallic material. Injection of the hydrazine is stopped after a cation resin arranged in a circulation line connected to the metallic material breaks, and at least the oxalic acid and the hydrazine in the reductive decontaminating agent are decomposed using a decomposing catalyst.

Abstract: A reactor coolant system of a pressurized water nuclear reactor with fuel assemblies in the core is simultaneously shutdown and decontaminated in less than 90 hours after the shutdown is initiated. A LOMI or Can-Derem decontamination reagent is added to reactor coolant to reduce iron and nickel in oxidized coatings before removing dissolved hydrogen and reducing the gamma emitting activity of the reactor coolant.

Abstract: An apparatus admits gas into the primary coolant of a pressurized water nuclear reactor having a coolant loop for a liquid coolant, in particular water, to which hydrogen is to be added. The coolant loop preferably includes a volume control tank for the coolant as well as at least one high-pressure pump which admits coolant that has been extracted from the coolant loop back into the coolant loop again. An admission point for the hydrogen is located in a suction line on the suction side of the high-pressure pump. A measurement line on the pressure side of the high-pressure pump communicates with the volume control tank or with a dewatering system. A device for measuring the hydrogen content in the coolant is incorporated into the measurement line. The measuring device is connected through a control device to a control valve, with which the delivery of hydrogen to the admission point can be controlled. The gas admission apparatus assures a definite, precisely maintained hydrogen content in the coolant.

Abstract: A radioactive substance decontamination method and apparatus which decontaminates a metal member contaminated by radioactive substance in a short period of time. This apparatus has (1) multiple reducing decontamination tanks having different radiation control values; (2) a carrier for immersing the metal member into the multiple reducing decontamination tanks and a washing tank; (3) a tube for transferring into the second reducing decontamination tank the reducing decontamination agent in the first reducing decontamination tank; (4) a reducing agent decomposer for decomposing a component contained in the reducing decontamination agent of the reducing decontamination tank where the radiation control value is the highest out of the reducing decontamination tanks connected by the tube; and (5) a washing tank for washing the reducing decontamination agent deposited on the decontaminated metal member.

Abstract: A foreign matter filter provided between a DFBN and a lower grid has two adjacent thin straps assembled into a lattice. The straps are equipped on the front and back sides with axially continuous protrusions.

Abstract: Disclosed a method for radioactive decontamination of a steel surface, which is performed by bringing the surface to be decontaminated into contact with a pickling solution comprising a first iron oxidation agent, wherein bringing into contact being achieved by means of the direct continuous introduction into the pickling solution of a gas comprising a second oxidation agent, and a device for implementing the said method.

Abstract: A method for removing a wide variety of radioactive contaminants from a contaminated surface sufficient for the surface to be classified as a low-level waste or as free release. Contaminated surfaces may be classified as Class C, Class B, Class A, or high-level radioactive wastes prior to treatment. An aqueous solution having a wetting agent and a complex substituted keto-amine is provided. The aqueous solution is left on the surface for a time sufficient to remove the radioactive contaminants into the aqueous solution which is then removed. Depending on the type and condition of the surface, an acid may be added to the aqueous solution to aid in the contaminant removal process. However, typical metals surfaces may often be treated effectively without the use of concentrated acids or with dilute concentrations of such acids. The method of the present invention has the effect of removing substantially all of the radioactive contaminants from a variety of previously contaminated surfaces.

Abstract: A water monitoring system for a nuclear reactor is provided. In an exemplary embodiment, the water monitoring system includes a fiber optic cable having a first end and a second end, with the first end configured to optically couple to the reactor cooling water distribution system, and at least one laser light source optically coupled to the second end of the fiber optic cable. The water monitoring system also includes a spectrophotometer optically coupled to the second end of the fiber optic cable.

Abstract: A method for removing radioactive contaminants from a given surface. An aqueous solution having a wetting agent and a complex substituted keto-amine is provided. The solution is left on the surface for a time sufficient to remove the radioactive contaminants into the aqueous solution which is then removed. Depending on the type and condition of the surface, a concentrated acid may be added to the aqueous solution to aid in the contaminant removal process. In such a case, a pH of less than 3.0, and preferably less than 1.5 is maintained. If a concentrated acid is used, the acidic solution containing radioactive contaminants is preferably neutralized by an alkaline material to a pH of between 5.5 and 9.0. Removal of thorium contamination from railcars is one useful application of the invention. The method of the present invention has the effect of removing substantially all of the radioactive contaminants from a previously contaminated surface.

Abstract: A method for removing radioactive contaminants from a given surface. An acidic solution having a pH of less than 3.0, and preferably less than 1.5, of a complex substituted keto-amine, and a mixture of a saturated and unsaturated lower alcohol (e.g. isopropyl alcohol and propargyl alcohol), and concentrated acid is applied to a contaminated surface. The solution is left on said surface for a time sufficient to remove the radioactive contaminants into the acidic solution and then removed. The acidic solution containing the radioactive contaminants is preferably neuralized by an alkaline material to a pH of between 5.5 and 9.0. Removal of thorium contamination from railcars is one useful application of the invention. The method of the present invention has the effect of removing substantially all of the radioactive contaminants from a previously contaminated surface.

Abstract: Surfaces of the structural components of a nuclear power plant exposed to reactor water are wetted with an electroless plating solution containing an electrical insulating substance. The electrical insulating substance has a high resistivity about 105 (100000) times those of the structural components of the nuclear power plant or above. A metal film containing the electrical insulating substance is formed on the surfaces of the structural components exposed to the reactor water by wetting the surfaces of the structural components with the electroless plating solution. Thus, the electrochemical corrosion potential of the structural components is reduced regardless of whether hydrogen is injected into the reactor water.

Abstract: A boiling water reactor having a reactor pressure vessel with two recirculation loops hydraulically connected thereto is decontaminated by installing plugs in the outlets of jet pump ram's head manifolds located within the reactor pressure vessel to isolate the recirculation loops from the reactor pressure vessel. A monitoring gas is bubbled into some of the ram's head manifolds through the plugs to monitor the process pressure within the manifolds and riser pipes connected with the manifolds. The level of the decontamination solution in the riser pipes can be determined by determining the differential pressure due to the vertical height of the decontamination solution in the loops.

Abstract: Passive aerosol retention apparatus positioned in the connecting vents of a nuclear reactor containment are described. The aerosol retention apparatus minimizes aerosol transport from the lower drywell to the upper drywell of the reactor containment. The retention apparatus includes a substantially cylindrical housing and a flow modulator positioned inside the housing and extending at least partially from a first end to a second end of the housing. The flow modulator includes a helically shaped baffle positioned in the housing so as to be coaxial with the housing. The baffle is coupled at each end to the housing by attachment bars.

Abstract: A process for removing undesirable material such as a radioactive contaminant from an underlying material. A solution containing fluoroboric acid and a material which affects the fluoroboric acid solution oxidation potential (Eh) is contacted with the contaminant material to cause its removal. The contaminant material is removed from the fluoroboric acid solution by contacting the fluoroboric acid solution which has been contacted with the contaminant material with a cation exchange resin.

Abstract: A skills based telephone call distribution system is disclosed. The system determines the informational needs of an incoming caller and defines a set of skills an agent should possess to serve the caller. A search is performed for an available agent possessing the skill set. Upon the search failing to locate an available agent possessing the skill set, the amount of time the caller may expect to wait therefor is estimated. The estimated time is compared to a maximum waiting time. If the estimated time is greater than the maximum waiting time, then the skill set is redefined to include a greater number of agents who may serve the caller. A new search is performed for an available agent possessing the redefined skill set.

Abstract: When hydrogen is generated within the containment of a nuclear power station, its containment atmosphere must be inerted. An undesired pressure buildup within the containment is prevented during such inerting with the apparatus and the method. It is possible to vent and inert the containment atmosphere simultaneously. A reversible activity holdup device is provided, which makes it possible to vent the containment atmosphere, without radioactive material being released into the surroundings. It is thereby also possible for the containment of a nuclear power station to be inerted even as a preventive measure, so that the safety of the nuclear power station plant is markedly increased.

Abstract: A process for the decontamination of radioactive materials which process comprises the steps of: i) contacting the material to be decontaminated with a dilute carbonate containing solution in the presence of ion exchange particles which either contains or have a chelating function bond to them; and ii) separating the ion exchange particles from the dilute carbonate containing solution. The radioactive materials which are treated may be natural materials, such as soil, or man-made materials such as concrete or steel, which have been subjected to contamination.

Abstract: A process for the recovery of chemical values, particularly uranium, nickel and/or radionuclides from process equipment theretofore employed in a uranium hexafluoride isotope enrichment cascade. Preferably, the process is carried out, in situ, at subatmospheric pressure employing the existing process equipment from which the chemical values are to be recovered. In one aspect, the process includes recovery of uranium values employing a gaseous fluorinating agent at subatmospheric pressure, followed by recovery of nickel values employing a gaseous reactant comprising a mixture of carbon monoxide and a promoter, preferably hydrogen sulfide and at subatmospheric pressure.

Abstract: A process for removing undesirable material such as a radioactive contaminant from an underlying material. A solution containing fluoroboric acid and a material which affects oxidation potential (Eh) is contacted with the undesirable material to cause its removal. The material is removed from the fluoroboric acid solution by contacting the solution with a cation exchange resin and fluoroboric acid is regenerated in situ for continuous removal of undesirable material.

Abstract: A pressure suppressing and aerosol scrubbing system configured to be located between low pressure upper containments associated with modular reactor vessels is described. In one embodiment, the pressure suppression and scrubbing system includes a water tank having connected, partially filled water chambers and a vertical baffle having horizontal vent holes positioned near the bottom of the tank. Each water chamber is connected by a vent/relief line to one of the respective rectangular upper containments. The partially filled water tank assures that the respective containments are isolated from each other under normal operating conditions due to the water trap inherent in the system. In the event that an accident occurs in one of the reactors, the affected containment is heated by the sodium spray and/or pool fire and such heat forces its way through the pressure suppressing and scrubbing system to the unaffected reactor containment.

Abstract: The present invention provides a method of decontaminating an article containing lead contaminated with radioactive material. The method includes contacting the article containing lead contaminated with radioactive material with a decontamination composition comprising about 0.01 to 5 percent, by weight, of a reductant, about 0.01 to 5 percent, by weight, of a compound selected from the group consisting of citric acid, alkali metal and ammonium salts of citric acid and mixtures thereof; 1 to 15 percent, by weight, of a compound selected from the group consisting of polyaminocarboxylic acid, alkali metal and ammonium salts of polyaminocarboxylic acid and the combination of a polyaminocarboxylic acid and a neutralizing compound and mixtures thereof; 0 to 1 percent, by weight, of a nonionic surfactant; 0 to 1 percent, by weight, of a dispersant; and 0 to 1 percent, by weight, of a corrosion inhibitor, and the balance water or other aqueous liquid.

Abstract: A system for suppressing the pressure inside the containment of a BWR following a postulated accident. A piping subsystem is provided which features a main process pipe that communicates the wetwell airspace to a connection point downstream of the guard charcoal bed in an offgas system and upstream of the main bank of delay charcoal beds which give extensive holdup to offgases. The main process pipe is fitted with both inboard and outboard containment isolation valves. Also incorporated in the main process pipe is a low-differential-pressure rupture disk which prevents any gas outflow in this piping whatsoever until or unless rupture occurs by virtue of pressure inside this main process pipe on the wetwell airspace side of the disk exceeding the design opening (rupture) pressure differential. The charcoal holds up the radioactive species in the noncondensable gas from the wetwell plenum by adsorption, allowing time for radioactive decay before the gas is vented to the environs.

Abstract: The core samples of solidified hazardous waste, such as nuclear waste, are extracted from waste material in a drum by inserting rotating tubular core drills into the waste material and then withdrawing the core drills with core samples of the waste material accumulated within the core drills. Preferably, the core samples are retained within plastic tubular retainers which are withdrawn from the core drills and capped. While the rotating tubular core drills are being inserted into the sample, pressurized gas is applied through are annular space between the tubular sample retainers and the walls of the core drills to cool the cutting heads and to expel cuttings away from the end of the drills up to the top surface of the material. In addition, the pressurized gas serves to keep contaminants off the outside surface of the plastic tubular sample containers.

Abstract: A process for the decontamination of solid surfaces contaminated with radioactive or heavy metal species using a solution based on one or more non-persistent complexing agents, or for the chemical cleaning of steam generator sludge using such a solution, or for removing radioactive or heavy metal species from a solution using a combination of a one or more non-persistent complexing agents and a solid support, followed in each case by thermal or thermal-chemical treatment to decompose said non-persistent complexing agent. The preferred non-persistent complexing agents are hydroxamic acids, and the most preferred is acetohydroxamic acid.

Abstract: In a method of treating a surface 12 of an object 10 contaminated with radionuclides 14, a laser source 16 is directed at the surface 12 to apply a local area 18 of intense heat to the surface 12. The laser source 16 is arranged to pass in a raster manner to cause local melting of the surface 12, surface 12 subsequently solidifying and fixing the radionuclides 14 therein. At least one layer of a coating material be applied before or after the application of the intense heat to fix and seal the radionuclides on or in the object.

Abstract: A process for obtaining a sample from an atmosphere in a closed gastight vessel, preferably from a reactor safety vessel of a nuclear power station, includes passing a sample through a venturi nozzle immediately upon entry of the sample into a sample-taking container in a vessel. The sample is mixed in the venturi nozzle with a transport fluid serving as a washing liquid. Gaseous constituents of the sample being soluble and/or condensable in the washing liquid are subsequently discharged together with the washing liquid from the sample-taking container and from the vessel by triggering a pressure reduction. A device for obtaining samples from an atmosphere in a closed gastight vessel, preferably from a reactor safety vessel of a nuclear power station, includes a sample-taking container having a bottom and a given volume. A washing liquid is disposed in the sample-taking container and has a volume being at most approximately equal to half of the given volume.

Abstract: A method and apparatus decrease the release of volatile radioactive iodine from a nuclear reactor pressure vessel containing a reactor core having fuel rods submerged in water. The method includes monitoring the pressure vessel to determine an accident condition and then injecting into the pressure vessel a stable iodide in liquid solution to mix with the reactor water for decreasing vaporization of volatile radioactive iodine discharged from the fuel rods. A reservoir initially stores the stable iodide in the liquid solution and is operatively joined to the pressure vessel through a supply conduit and a normally closed valve which is selectively opened following the accident condition to inject the stored iodide liquid solution into the pressure vessel to mix with the water therein.

Abstract: A process for decontaminating radioactive material comprises the step of contacting the material with a dissolving composition to dissolve the contaminants in the material, said composition comprising a dilute solution of about 0.05 molar ethylene diamine tetraacetic acid, about 0.1 molar carbonate, about 10 grams per liter hydrogen peroxide and an effective amount of sodium hydroxide to adjust the pH of the composition to a pH from about 9 to about 11. Also included are the steps of separating the dissolving composition containing the dissolved contaminants from the contacted material and recovering dissolved contaminants from the dissolving composition that has been separated from the material. A composition for dissolving radioactive contaminants in a material, comprising a dilute solution having a basic pH and effective amounts of a chelating agent and a carbonate sufficient to dissolve radioactive contaminants is also provided.

Abstract: High velocity reactor coolant water in a boiling water reactor or a pressurized water reactor transports radioactive ions and particles from a nuclear reactor vessel to the balance of the reactor coolant system where they deposit on chromium (III) oxide-containing surfaces. These radioactive deposits are removed in a dilute chemical decontamination process wherein permanganate ion-containing reactor coolant water is circulated throughout a reactor coolant system to oxidize chromium (III) oxide surfaces of the system to chromium (IV) oxide. Formic acid is added to the permanganate ion-containing reactor coolant water and then the formic acid-containing water is circulated throughout the reactor coolant system to reduce unreacted permanganate ions in the reactor coolant water to manganous ions.

Abstract: A nuclear reactor has a passive system for adjusting the pH of post accident water in the containment vessel. A basic liquid is stored in the containment vessel at an elevation above the maximum post accident water level. When radiation levels in the containment vessel exceed a predetermined, normal level the basic liquid is gravitationally drained into sumps located in the containment vessel below the maximum post accident water level where it mixes with emergency core cooling system water, raising the pH of the water to about 7.

Abstract: Where a concrete structure (12) has been contaminated with tritium (whether as gas or as water) the tritium atoms take the place of ordinary hydrogen atoms in water and in hydroxyl groups in the concrete, rendering it radioactive. The degree of contamination may be reduced by irradiating the surface with microwaves to vaporize water, while extracting water vapor from the surface region through a dust filter (28) and a water trap (30). This can considerably reduce the radioactivity, and hence the cost of disposal of the concrete.

Abstract: A device for monitoring the stack exit air in a reactor installation consists essentially of a pressure relief line (2) which connects the containment vessel (1) to the stack (5) and in which a filter unit (3) is located. Downstream of the filter, a sampling point (6) is provided in the pressure relief line, from where gas mixture is branched off via a sampling line (7). This gas is passed through a measurement section (14) and then returned into the pressure relief line (2). The concentration of the gas is reduced in a dilution unit (8) upstream of the measurement section (14). Cooling of the gas sample in the sampling line (7) before dilution is prevented by means of a heater (24).

Abstract: A filtered venting system located in association with a reactor containment vessel installed in a reactor building comprises a filter device disposed in the reactor building and including filter means, a first venting line disposed on an upstream side of the filter device and having one end connected to the reactor containment vessel and another end connected to the filter device, a stand-by gas treatment system including outlet fan means or pump means and connected to the first venting line at the downstream side of the fan or pump means, and a second venting line disposed at a downstream side of the filter device and another end connected to an outlet means/ The filter device being utilized for the stand-by gas treatment system for treating and removing a radioactive substance contained in an atmosphere delivered from the reactor containment vessel.

Abstract: The apparatus comprises a conduit connected to a containment vessel to supply air to a water bath contained in a basin. The conduit is connected to a plurality of air nozzles in the water bath, each of which forms a unit together with a perforate baffle plate disposed above the nozzle to intensively mix the emerging air with water. A set of static mixer elements enclosed by a jacket is disposed in the water bath above the baffle plate.

Abstract: Method and apparatus for avoiding potential accidents in water-cooled nuclear reactors of the type having an enclosing containment, due to the formation of an explosive gas mixture in the containment. Air is withdrawn from the containment and fed to at least one internal combustion engine as combustion air for the engine. The exhaust gases created by the internal combustion engine are then recycled back into the containment. The result is the lowering of the oxygen partial pressure in the containment to below the critical limit for oxyhydrogen explosion.

Abstract: In this decontamination process, the surfaces contaminated with radioactive substances, in particular on components of cooling circuits in nuclear reactors, are treated in a first treatment step with an aqueous decontamination solution, containing chromic acid and permanganic acid, at a temperature in the range from 270 to 350 K, in particular at usual room temperature. The contaminated surface layers are thus oxidized by means of the permanganic acid, while the effect of the chromic acid is that the modified surface layers do not adhere firmly. In a second treatment step, the surface layers thus modified are removed by a chemical treatment in the same temperature range, as a result of dissolution, or/and removed by mechanical or hydraulic action. Aqueous solutions of organic acids are suitable for the chemical treatment in the second treatment step, it also being advantageously possible to add reducing agents and complexing agents and/or corrosion inhibitors.

Abstract: Process for the radioactive decontamination of metal surfaces, particularly portions of the primary circuits of water-cooled nuclear reactors, characterized in that it comprises subjecting said surfaces to the successive stages of an oxidizing pretreatment with the aid of a solution of potassium permanganate KMnO.sub.4 and nitric acid, rinsing with demineralized water and then reducing treatment in a basic medium with the aid of a solution of alkali metal gluconate of formula HOH.sub.2 C--CHOH--CHOH--CHOH--CHOH--COOM, in which M is an alkali metal chosen from among Na and K, as well as soda NaOH.

Abstract: The wetwell space in a suppression pool of a nuclear reactor containment is continuously ventilated by exhausting gas therefrom, while at the same time, during normal system operation atmospheric air from a source of same is admitted to the wetwell but such admission being blocked during a LOCA. All exhaust flow from the wetwell is conveyed through a conduit that outlets at a remote elevated location in the atmosphere. All exhaust flow through the conduit is before outletting therefrom passed through gas treatment operation wherein any particulates in the gas mixture are removed. Further treatment of the gas with charcoal to adsorb noble gases can be carried out. In normal reactor operation the ventilation flow rate is at minimal level. However on occurrence of a loss-of-coolant-accident, highly heated gases from the containment drywell are passed into the suppression pool where condensables condense while non-condensable gases are cooled and vent to the wetwell.

Abstract: A unique clean-up sub-system for chemical decontamination of nuclear reactor primary systems is disclosed. Chemically-processed fluids containing suspended and dissolved solids are directed through a back-flushable filter and, thereafter, through one or more cartridge filters. After this initial filtering of suspended solids, the process fluid is directed to one or more demineralizer banks for removal of dissolved solids, followed by additional cartridge filtering to remove any resin fines carried out of the demineralizer banks. After final filtering, the process fluids are returned to the primary system, with or without chemical injection.

Abstract: A unique and optimum nuclear steam supply system operating configuration for integration of a chemical decontamination system is disclosed. The chemical decontamination system is connected to, and returns to, the residual heat removal system downstream of a residual heat removal heat exchanger, thereby utilizing the residual heat removal system to control the temperature of process fluids entering the decontamination system. A reactor coolant pump or pumps generates heat for the chemical processes as needed and a nitrogen blanket within the primary system pressurizer is utilized for system pressure control.