Abstract: A combined lower end fitting and debris filter for a nuclear fuel assembly is provided that does not require multiple parts, welding, brazing, mechanical fasteners, drilling or EDM operations to form the coolant flow holes. The lower end fitting and debris filter are cast as a single work piece that includes the coolant flow holes in the casting process. This is accomplished by casting the sections of the filtration surface having flow holes in a thickness that allows for the small coolant flow holes to be formed as part of the casting process.

Abstract: A strainer device for filtering water to an emergency cooling system in a nuclear power plant containment area having a lower part which forms a pool in which the strainer device is mounted. The device includes a strainer housing with separate strainer walls between which a flexible strainer means operates. The unit is arranged to be kept in a first position when water is drawn through one of the strainer walls, in which position it interrupts the connection between the other strainer wall and a suction conduit. By inherent flexibility, a shield means is automatically switched over to a second position which opens the connection between the second strainer wall and the suction conduit, as soon as the first strainer wall is clogged by impurities to such an extent that a low-pressure arises in the space between the first strainer wall and the shield means unit, which low-pressure brings about the switching-over by its suction effect.

Abstract: A unitary one-piece lower tie plate grid has a lower portion and an upper portion for supporting the fuel rods. The lower tie plate grid includes cylindrical boss portions arranged in square matrices for receiving the lower end plugs of the fuel rods. Web portions interconnect the boss portions along the sides of the matrices. The lower grid portion includes a plurality of openings which open into the flow spaces defined by the convex portions of the bosses and the webs within each square matrix of the upper portion of the tie plate. Coolant flows through the lower flow openings into the flow spaces for further flow upwardly about the fuel rods. The openings are defined by the convex lower portions of the bosses and webs, as well as projections which extend laterally inwardly from the convex surfaces of the lower boss portions toward a central region in the middle of the square matrix.

Abstract: The apparatus is provided with a line (1) connected to the containment for feeding air to a water bath (5). The line (1) is connected to plurality of nozzles (4) disposed in the water bath (5) having at least one perforate baffle plate (27) disposed above said nozzles. A set (6) of static mixing elements (30, 31, 32) surrounded by a jacket (7) is disposed above said baffle plate (27). A dry separating stage is disposed above the water bath (5) and the set (6) and consists of an entry separator (8) and an agglomerator (9) which are in the form of annular discs. Air emerging from the set successfully flows through the entry separator (8) and the agglomerator (9) in opposite directions. The entry separator (8) and the agglomerator (9) consist of static mixing elements.

Abstract: A device for trapping migrating bodies within the steam generator or secondary circuit of a nuclear installation is constituted by grids (6) placed between the upper part of the tube casing (8) and the pressure casing (7) of the steam generator. The meshes of the grids are so dimensioned as to prevent the passage of objects liable to jam between the tubes of the tube bundle of the primary circuit.

Abstract: A debris catching arrangement is disclosed for incorporation within the flow plenum up stream or below the rod supporting grid of the lower tie plate assembly. The device is preferably placed within the lower tie plate flow plenum between the fuel bundle inlet orifice and the rod supporting grid structure supporting the fuel rods; alternate placement can include any inlet channel upstream of the fuel rods including the fuel support casting. The disclosed debris catching designs include successive side-by-side coil springs placed in layers across the tie plate plenum. Preferably, the respective tie plates are placed in alternating directions with a first layer of springs oriented at 90.degree. to an alternate and underlying layer of springs. Multiple layers of such springs are used with four layers being preferred. At their respective crossing points, the springs of adjacent layers are joined--as by welding--with the result that the filter is a solid unitary mass.

Abstract: In a boiling water reactor fuel bundle, a three dimensional debris catching grid construction is placed within the flow volume defined by the lower tie plate assembly between the inlet nozzle and upper fuel rod supporting grid. A perforated plate is utilized having round holes as small consistent with the prevention of inadvertent closure due crudding and a hole pitch consistent with mechanical integrity requirements. The perforated plate is placed in a three dimensional construction such as a dome, cylinder, pyramid, inverted pyramid or corrugated construction spanning the flow volume of the lower tie plate assembly. As a consequence of this three dimensional grid construction, the total flow through area of the perforations in the metal plate does not introduce appreciable pressure drop in the lower tie plate assembly between the inlet nozzle and the rod supporting grid.

Abstract: An improved tool for removing the highly contaminated inner filter from a control rod drive during a maintenance operation. The tool may also be used to install the inner filter by pushing the inner filter on and locking the spring clip onto flats of the center lug of the control rod drive stop piston. The tool has a collet with flexible fingers which are inserted inside the inner filter while flexed radially inward. After the collet is inserted, a retractable cam with a conical bearing surface is retracted to a position whereat it urges the collet fingers radially outward to clamp the collet onto the inner filter. The locked filter must be rotated before removal. With the inner filter coupled to the collet, the tool is then pulled out to remove the inner filter from the control rod drive.

Abstract: An analytical testing means for determining the ion contents of nuclear reactor coolant water comprising ion chromatograph means and a conductivity detector. Reagent containing ion exchange resin is recycled, concentrated and the ion exchange resin regenerated to provide a more economic procedure.

Abstract: The reactor coolant system (RCS) of a pressurized water reactor (PWR) is chemically decontaminated and cleaned utilizing apparatus which is comprised of components designed to operate at low pressures while still utilizing installed reactor coolant pumps and/or the residual heat removal pumps to generate the high flow rates required for the process. A high volume diverted flow of reactor coolant from the RCS is passed through letdown valves to reduce the high pressure produced by the installed pumps. Chemical decontamination and cleaning agents are mixed with the low pressure diverted flow and returned to the RCS by high head injection pumps. Contamination solubilized by the decontamination and cleaning agents is removed as the reactor coolant is recirculated through demineralizers. Filters remove particulates, and fines from the demineralizer resins.

Abstract: A reactor water cleanup system includes a reactor pressure vessel containing a reactor core submerged in reactor water. First and second parallel cleanup trains are provided for extracting portions of the reactor water from the pressure vessel, cleaning the extracted water, and returning the cleaned water to the pressure vessel. Each of the cleanup trains includes a heat exchanger for cooling the reactor water, and a cleaner for cleaning the cooled reactor water. A return line is disposed between the cleaner and the pressure vessel for channeling the cleaned water thereto in a first mode of operation. A portion of the cooled water is bypassed around the cleaner during a second mode of operation and returned through the pressure vessel for shutdown cooling.

Abstract: A nuclear fuel assembly lower end fitting. Two plates each having a network of diagonal and lateral ribs in conjunction with hubs for the guide thimble hole pattern are provided. The pitch between ribs corresponds to one-half of the fuel rod pitch. This allows for the fuel rods to be supported by every other rib. One plate is rotated horizontally ninety degrees relative to the other plate so that the lateral ribs of the plates are at right angles. A screen formed from approximately 0.03 inch diameter wire with 0.100 inch pitch is provided with guide tube bosses. The plates and screen are rigidly attached to each other to form a debris filtering lower end fitting.

Abstract: An anion exchange method conducted at a high temperature, which comprises using a crosslinked anion exchanger which comprises structural units having a quaternary ammonium group of the following formula (a) and structural units derived from an unsaturated hydrocarbon group-containing crosslinkable monomer, and of which at least 90% of anion exchange groups are present in the form of a group represented by ##STR1## as defined in the following formula (a): ##STR2## wherein R is a --(CH.sub.2).sub.n --group (n=an integer of from 3 to 18) which may include a cyclic hydrocarbon, each of R.sub.1, R.sub.2 and R.sub.3 which are independent from one another, is a C.sub.1 -C.sub.8 hydrocarbon group or a C.sub.1 -C.sub.8 alkanol group, the benzene ring of the formula (a) may be substituted by an alkyl group or a halogen atom, or may be condensed with other aromatic ring, and X is an anion.

Abstract: A method for shredding and packing used structural elements of nuclear reactors, such as fuel assembly cases, comprises the steps of shredding structural elements to scrap pieces; flushing the scrap pieces in a transport container and flushing away highly radioactive particles of foreign matter and collecting the particles in the interior of the transport container; packing the flushed scrap pieces around the particles of foreign matter collected in the interior; and inserting the packed transport container into a sealable disposal container.

Abstract: An improved tool for removing a highly contaminated outer filter from a control rod drive during a maintenance operation. The tool slides onto the control rod drive and surrounds the outer filter with a shield. The shield has a window for removing the screws used to mount the outer filter on the control rod drive. The tool has a support for the spud on the inside thereof. A U-shaped handle is slidably inserted into guideways so that it interlocks with circumferential slots in the shield. The arms of the inserted U-handle latch underneath the ring flange of the outer filter, whereby the outer filter is captured by the tool. The filter-mounting screws are then removed by unscrewing through the aligned window in the shield. Thereafter, the outer filter is removed from the CRD when the outer filter removal tool is lifted.

Abstract: In a boiling water nuclear reactor fuel bundle, a debris catching arrangement is disclosed for incorporation within the flow plenum up stream or below the rod supporting grid of the lower tie plate assembly. The device is preferably placed within the lower tie plate flow plenum between the fuel bundle inlet orifice and the rod supporting grid structure supporting the fuel rods; alternate placement can include any inlet channel upstream of the fuel rods including the fuel support casting. Paired plates defining offset holes and bosses are utilized. The bosses are supported at plate webbing between the respective holes. The holes are preferably square in plan with appropriately relieved and rounded corners defining the edges of the webbing. The bosses may be cylindrical, square or rectangular in cross-section. In confrontation of plates to form the debris catching grid, each boss from one plate confronts a hole from the remaining plate.

Abstract: A chemical decontamination clean-up system for use on-line in a nuclear reactor primary system includes a pump arrangement within the nuclear reactor primary system for pumping primary system fluids to a cleaning system located directly downstream from the pump assembly. The cleaning system includes a plurality of first demineralizer banks arranged in a predetermined flow pattern for receiving the primary system fluids. Each of the first demineralizer banks comprises at least two individual, resin-filled demineralizers arranged in parallel wherein primary system fluids are demineralized. Each of the demineralizer banks includes valving for selectively directing the primary system fluids from the pump arrangement to selected demineralizer banks in the plurality of the first demineralizer banks. A second demineralizer bank receives the primary system fluids from the plurality of first demineralizer banks.

Abstract: A fuel assembly supporting structure for a nuclear reactor fuel assembly which comprises a two-way shape-memory alloy. A shape-memory alloy is selected which has an overall transition temperature range substantially above atmospheric temperature and substantially below a temperature experienced by the shape-memory alloy under reactor operating conditions. By using a shape-memory alloy in the design, the support structure assumes a first configuration for securely supporting one or a plurality of nuclear reactor components at a temperature above the overall transition temperature range and assumes a second configuration for loosely engaging the reactor components below the transition temperature range.

Abstract: A process for selective separation of niobium from proton irradiated molybdenum targets is provided and includes dissolving the molybdenum target in a hydrogen peroxide solution to form a first ion-containing solution, contacting the first ion-containing solution with a cationic resin whereby ions selected form the group consisting of molybdenum, biobium, technetium, selenium, vanadium, arsenic, germanium, zirconium and rubidium remain in a second ion-containing solution while ions selected from the group consisting of rubidium, zinc, beryllium, cobalt, iron, manganese, chromium, strontium, yttrium and zirconium are selectively adsorbed by the cationic resin; adjusting the pH of the second ion-containing solution to within a range of from about 5.0 to about 6.0; contacting the pH adjusting second ion-containing solution with a dextran-based material for a time to selectively separate niobium from the solution and recovering the niobium from the dextran-based material.

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: The adaptor plate (11) comprises ribs (12) which are substantially perpendicular to its faces, projecting from its lower face, delimiting between them cells and zones (15) into each of which emerges a plurality of through-openings (16) of substantially square cross-section which are arranged in a predetermined pattern.

Abstract: A lower tie plate for a nuclear fuel assembly is provided via an integral casting including a frame containing a first plurality of guide tube bosses in a central portion thereof, a second plurality of guide tube bosses concentric with the first plurality of guide tube bosses, and a plurality of teardrop shaped struts connecting the first and second guide tube bosses to one another and to the frame. The guide tube bosses serve to respectively directly receive individual guide tube cap screws of guide tubes of the nuclear fuel assembly. The interior top portion of the lower tie plate is configured to receive and support a debris screen.

Abstract: A storage canister for spent nuclear fuel rods, having loading and storage configurations, has an open end and an apertured end wall, and means therein defining a plurality of rod locations. The canister also has movable means therein for vertically offsetting adjacent rods within the canister so that any pair of adjacent rods are vertically offset from each other. The movable means is positioned during loading to permit fluid flow into and out of the canister through the apertured end wall and in the storage configuration blocks at least one of the apertures in the end wall. The movable means may also be used to lift the fuel rods such that their tops extend above the canister body to permit removal of one or more rods. A closure member for the open end has a locking mechanism for locking it to the canister and a tamper indicating mechanism.

Abstract: A control rod driving hydraulic system of a control rod driving system of a nuclear power plant, in utilization of condensate as a control rod driving water comprises a water pressure control unit arranged for each control rod and a water pressure supply unit for commonly supplying water pressure to all control rods. The water pressure supply unit comprising a pump mechanism operatively connected to a condensate supply source for driving the control rod driving water, a filter mechanism operatively connected to the condensate supply source and the pump mechanism for filtering the condensate as the control rod driving water, a valve unit for regulating quantity of flow of the control rod driving water, and a valve unit for regulating pressure thereof. The filter mechanism including at least one hollow fiber filter unit for purifying the control rod driving water. The hollow fiber filter unit includes a backwash regeneration equipment.

Abstract: The spent fuel pit of a pressured water reactor (PWR) nuclear power plant has sufficient coolant capacity that a safety rated cooling system is not required. A non-safety rated combined cooling and purification system with redundant branches selectively provides simultaneously cooling and purification for the spent fuel pit, the refueling cavity, and the refueling water storage tank, and transfers coolant from the refueling water storage tank to the refueling cavity without it passing through the reactor core. Skimmers on the suction piping of the combined cooling and purification system eliminate the need for separate skimmer circuits with dedicated pumps.

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: In addition to the metal-fiber filter and molecular sieve of a depressurization system for the containment vessel of a nuclear reactor, within an auxiliary equipment building adjacent the structure surrounding the containment vessel, at least one metal-fiber filter and at least one molecular sieve form filter elements of a system for evacuating the space between the structure and the containment.

Abstract: Process for the conditioning or recycling of used ion cartridges.The invention relates to a process for the treatment of ion cartridges or elements ensuring the treatment of contaminated waters of storage ponds or pools for nuclear reactor fuels. By cartridge transfer and suction means, said treatment consists of extracting the ion exchange resins contained in the cartridge.When the resin has been extracted, a conditioning process makes it possible to decontaminate and then condition, independently of the resinous substance, the metal structure constituting the cartridge.When the resin has been extracted, a recycling process makes it possible to clean the impurities from the metal structure and fill it again with new resin.The invention has applications in the nuclear field and in particular in the field of treatment and conditioning of nuclear waste.

Abstract: An apparatus for providing an inventory of an isotopically enriched acidic solution of an element that is capable of forming a water soluble weakly acidic solution at temperatures amenable to ion exchange and having a lower molecular weight isotope fraction and a higher molecular weight isotope fraction is disclosed. This apparatus includes at least two ion exchangers, each being temperature dependent with respect to their storage capacity of said lower and higher molecular weight isotopes, a hot tank containing a hot tank solution and a cold tank containing a cold tank solution both flow coupled to the ion exchangers. A first series of valves is selectively operable to direct the hot tank solution to one of the ion exchanger and to direct the cold tank solution to the other ion exchangers. A second series of valves is selectively operable to direct the flow from the ion exchangers to either the hot tank or the cold tank. An analyzer for sampling the solution is located upstream from the hot tank.

Abstract: Device for filtering a liquid circulating in the cooling circuit of a nuclear reactor, comprising a support (6) to be attached to the core-supporting plate (1) of the reactor, a metal grating (10) retained on the support, and a bearing device (12,13,14) for the central part of the grating (10) fixed to the support (6). The grating (10) consists of a network of intersecting wires in the form of a spherical dome. It is obtained by stamping a flat grating, the wires of which have previously been brazed to one another at each of the nodes of the network.

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 nozzle (8) comprises a transverse element consisting of a cross-braced structure (14) comprising wall elements (15) delimiting cells (16) of large dimensions. Ends of a plurality of mutually parallel leaves (18) are fixed to the inside walls of each of the cells (16) so that their faces are substantially parallel to the direction of circulation of the cooling water through the nozzle (8). The leaves (18) provide between them spaces of a width which is less than the size of the particles likely to be entrained in the cooling fluid and to lodge in the fuel assembly.

Abstract: A fuel assembly for a boiling water nuclear reactor contains a plurality of vertical fuel rods, which are arranged between a bottom tie plate and a top tie plate in a surrounding vertical casing part. At its lower end the casing part is connected to a bottom part which is provided with an inlet opening for water for conducting water in through the bottom tie plate, through the space between the fuel rods in the vertical casing part and out through the top tie plate. A debris catcher with a low flow resistance to water is provided below or above the bottom tie plate and at a distance from the bottom tie plate.

Abstract: A waste disposal site, such as an ultimate disposal site for radioactive substances, includes installed waste having hollow spaces remaining therebetween. Packing material fills the remaining spaces. At least one substance to which gaseous toxic substances such as radioactive gases adhere, is admixed with the packing material.

Abstract: The lower end nozzle (1) comprises an adaptor plate (2), supporting feet (3) and a particle retention device (6) consisting of a filter plate pierced with holes and attached to the bottom face of the adaptor plate (2) over a substantial portion of its surface.

Abstract: A decontaminating apparatus for cleaning radioactive contaminated surfaces and recovering for disposal the contaminated material, including a first recovery unit comprising a vacuum creating source in association with a second recovery unit that filters and demists the vacuum recovered contaminated material, and a third recovery unit that initially vacuum recovers the contaminated material and separates the same into fluid and air borne contaminates. The second and third recovery units each having a critical mass control responsive to the volume of contaminated material vacuumed from the surface being decontaminated.

Abstract: A nuclear reactor having a chemical decontamination system is provided in which every piece of decontamination equipment which processes radioactive materials is located within a decontamination building. The decontamination system is designed to provide for adequate protection for personnel safety and also incorporates a modular design for equipment transportation and storage.

Abstract: The lower connector comprises an adaptor plate of square shape, traversed by water passage orifices, and a filtration plate pierced with holes of small dimensions and abutting against the adaptor plate. The water passage orifices of the adaptor plate are arranged completely symmetrically in relation to the medians and to the diagonals of the adaptor plate. The set of orifices in each of the zones of the adaptor plate limited by a diagonal and a median comprises orifices have an oblong cross-section and, if appropriate, water passage orifices of a different shape. The filtration plate comprises sets of holes of small dimensions arranged in the zones of the plate which come into alignment with the oblong orifices of the adaptor plate.

Abstract: The particle retaining device comprises a plurality of tubes (18) parallel to fuel rods (14) of the fuel assembly, in all gaps between adjacent fuel rods (14) and throughout the length of a zone located between the upper part of a bottom nozzle (2) and the lower part of the spacer grid which is closest to the bottom nozzle (2).

Abstract: Water testing apparatus for monitoring circulating water coolant in service within a water cooled nuclear reactor system is disclosed. The invention is an improvement in such water testing apparatus and comprises filtering and a preconditioning of selected sample specimens of the coolant water with a pH adjustment for inhibiting unbalancing an equilibrium in solution of water coolant with ion solutes.

Abstract: A unique resin processing system for providing and removing resin to large demineralizer vessels during chemical decontamination of nuclear reactor primary systems is disclosed. Resin is premeasured in a batching tank for accurate filling of demineralilzer resin bed while minimizing personnel radioactivity exposure. Sluice water transfers spent resin to a storage tank and, thereafter, is recycled for subsequent sluicing operations. Spent resin from the storage tank is periodically delivered to high integrity containers for ultimate disposal.

Abstract: The filtration plate (10), arranged in the lower part of the fuel assembly and ensuring the retention of particles contained in the cooling fluid of the reactor, has at least one active zone where it is pierced with holes (12) of a size determined according to the size of the particles to be retained. The active zones of the filtration plate come into alignment with a water-passage hole through the lower core plate of the reactor when the assembly is in operation. The water-passage orifices of the filtration plate (10) can consist of cutouts of square or triangular form or of stamped parts of the plate or be delimited by parallel lamellae constituting a grating.

Abstract: A nuclear reactor having a chemical decontamination system is provided in which every piece of decontamination equipment which processes radioactive materials is located within the containment chamber of the nuclear reactor. This decontamination system therefore presents advantageous safety benefits over an outside of containment system in the unlikely event of a leak of radioactive materials from the decontamination system.

Abstract: The connector comprises an adaptor plate (6), supporting feet (7) and a flat element (10) constituting a filter for the retention of particles contained in the cooling fluid of the nuclear reactor. The flat element (10) is fastened to the lower part of the supporting feet (7) of the assembly, in order, during operation, to come to rest on the lower core plate (1) of the reactor. At least one zone of the flat element (10) constitutes a filtration grating located opposite a cooling-water passage (2) through the lower core plate (1).

Abstract: An apparatus for cleaning up reactor coolant includes a piping for taking out water in a reactor core, and this piping is provided separately from a primary loop recirculation piping and has its open end located at the bottom of a reactor pressure vessel. The taking-out piping extends upward from the open end within the reactor pressure vessel and extends through and outside of the side wall of the reactor pressure vessel. In a preferred form, the taking-out piping is provided near the highest position of its portion outside the reactor pressure vessel with a siphon brake valve.

Abstract: A nuclear fuel assembly with a debris filter. The lower end fitting of the fuel assembly has a stamped plate attached thereto that serves as a debris filter immediately upstream of the fuel rods. The stamped plate is provided with a plurality of flow holes in a size and pattern that provides filtration of debris damaging to the fuel rods while maintaining adequate coolant flow through the fuel assembly.

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: 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: The device comprises a pipe for aspiration and delivery of water from a well, a column suspended from a traveling crane located above the well and an aspiration head fixed at the end of the column opposite to the crane. The aspiration head is composed of two hollow walls assembled to one another, between which there is a filtration wall separating the internal volume of the head into a first part having an aspiration opening and a second part connected via a conduit to the aspiration pipe.

Abstract: Cations and anions contained as impurities in a spent organic solvent can be removed by an alkaline aqueous solution passing through inside of hydrophobic porous membrane such as hollow fibers for capturing anions and by an acidic aqueous solution passing through inside of hydrophobic porous membrane such as hollow fibers for capturing cations at the same time so as to regenerate the organic solvent. An apparatus suitable for removing cations and anions simultaneously from the spent organic solvent is also provided.