Abstract: The invention relates to an apparatus for the separation of hydrogen and/or euterium and tritium from an inert gas flow which is contaminated with hydrogen and/or deuterium and/or tritium, wherein the inert gas which is to be purified is conducted along the primary side of an exchange wall for hydrogen isotopes.The secondary side of the exchange wall has applied thereto an agent which so chemically reacts with the permeating hydrogen isotopes that the hydrogen isotope or the hydrogen isotopes which are to separated out of the inert gas flow which is to be purified, are bound in a reaction product which is transportable in a gas flow which is not capable of permeating through the exchange wall, and wherein along the secondary side of the exchange wall there is conducted a carrier gas flow which conveys off the reaction product.

Abstract: A process for the controlled discharge from a reactor containment structure of a gas cooled nuclear power plant and the installation for achieving this process include parallel discharge circuits from a reactor containment structure to a discharge stack. The flow of discharge from the reactor containment structure normally flows in a primary discharge circuit and may be directed wholly or partially to the parallel secondary discharge circuit. The secondary discharge circuit contains means for reduction of the temperature of the discharge, means for deposition of particulate fission products and they also contain means for recombination of combustible gases and means for filtration of the discharge. Nuclear power plant installations and processes for controlling the discharge from a reactor containment structure in this fashion permit safe discharge of naturally occurring leakage for gas cooled nuclear reactors, as well as leakage occurring in the event of reactor failure.

Abstract: A compound for chemically impregnating an activated charcoal bed for efficiently removing radioactive iodine from air flow from an area through a chemically impregnated carbon filter in a nuclear air cleaning system in which the compound is selected from Quinuclidine.CH.sub.3 I; Triethylenediamine.2CH.sub.3 I; and Hexamethylenetetramine.CH.sub.3 I.

Abstract: The invention relates to apparatus for the separation of hydrogen and/or terium and tritium from an inert gas flow which is contaminated with hydrogen and/or deuterium and/or tritium, wherein the inert gas which is to be purified is conducted along the primary side of an exchange wall for hydrogen isotopes. The secondary side of the exchange wall has applied thereto an agent which so chemically reacts with the permeating hydrogen isotopes that the hydrogen isotope or the hydrogen isotopes which are to be separated out of the inert gas flow which is to be purified, are bound in a reaction product which is transportable in a gas flow which is not capable of permeating through the exchange wall, and wherein along the secondary side of the exchange wall there is conducted a carrier gas flow which conveys off the reaction product.

Abstract: A method for operating a nuclear reactor having reactor coolant including an exhaust gas source and an exhaust gas system connected to the exhaust gas source, the exhaust gas system having at least one compressor connected to the exhaust gas source, a gas cooler connected to the compressor, a first reducing valve connected to the gas cooler, a switching valve connected to the first reducing valve, a moisture adsorber connected to the switching valve, a delay line normally connected in parallel with the moisture adsorber, a gas loop connected between the moisture adsorber and the compressor, a flue connection set at a given pressure during normal operation, and a second reducing valve connected between the delay line and the flue connection, includes interconnecting the delay line and the moisture adsorber in series, setting the flue connection to a pressure at least twice as high as the given pressure, reversing the switching valve thus allowing the exhaust gas to pass from the moisture adsorber to the delay

Abstract: The invention resides in an apparatus for the decontamination of radioactivated metallic waste by the electrolytic oxidation-reduction with an aqueous nitric acid solution containing trivalent cerium ions, i.e. the step of converting the trivalent cerium ions into tetravalent cerium ions through electrolytic oxidation and the step of dissolving the surface layer of the radioactivated metallic waste by oxidizing it with the electrolytic solution now vested with the oxidative power of the freshly produced tetravalent cerium ions and, at the same time, effecting regeneration of the tetravalent cerium ions.

Abstract: A nuclear reactor, particularly a light water reactor or a helium-cooled high-temperature reactor, is provided with a pressure relief system for relieving pressure resulting under fault conditions from coolant in the reactor pressure vessel and/or the protective vessel of the reactor, wherein the coolant is conducted from the vessel or vessels to a pressure relief station downstream thereof. At the pressure relief station the coolant is fed into a liquid reservoir 4 from which the coolant in gaseous or vapor form is fed sequentially through a washing cyclone 13 and a drying cyclone 25. Most of the radioactive fission products carried by the coolant will have been removed by the liquid reservoir 4 and the washing cyclone 13, and the coolant leaving the cyclone 25 may be safely discharged to atmosphere. Both the liquid reservoir 4 and the washing cyclone 13 are provided with cooling circuits 8 to 12 and 14 to 23 respectively for the liquids.

Abstract: A barrier system for a high temperature reactor. The reactor utilizes spherical fuel elements consisting of coated particles of a fissionable material embedded in a graphite matrix, the coating forming a first safety barrier against the release of fissionable material, and the graphite matrix a second such safety barrier. The reactor is surrounded by a prestressed concrete pressure vessel clad on the inside with a metal liner. The metal liner acts as a third safety barrier, while the concrete body of the prestressed concrete pressure vessel forms the fourth, and outermost safety barrier. A plurality of passages are located in the pressure vessel which are closed off by closure means. The closure means provide sealment between the third and fourth barriers in the area of the passages. By utilizing the concrete pressure vessel as a safety barrier in this manner, the need for a separate protective reactor housing is eliminated.

Abstract: Process and apparatus for confining the pollution of an isostatic pressing enclosure.At the end of an isostatic pressing operation, a glove box is sealingly fixed above the enclosure, the plug is removed from the latter and deposited within the glove box, after which the sampling and inspection operations necessary for detecting any contamination are performed.Application to the compression of radioactive waste by isostatic pressing.

Abstract: A nuclear fuel element comprises plutonium-containing fuel pellets filled in a cladding with both end sealed with end plugs. One end plug has a filter at the inside and a passage communicating with the space in the cladding through the filter. The passage is sealed at the surface part of the end plug by welding. The filter and the passage in the end plug are utilized for withdrawing a gas in the cladding filled with the fuel pellets in a process for fabricating the nuclear fuel element. The filter traps nuclear fissionable materials in the cladding to prevent its leakage to the outside. After the withdrawal of the gas, a helium gas is filled in the cladding through the passage in the end plug. After completion of these operations, the passage in the end plug is sealed as mentioned above.

Abstract: Control rods are inserted into the core of a nuclear reactor in operation to shut down the reactor output. Before completion of entire control rod insertion, a high-temperature coolant flowing in piping for a reactor water clean-up system is sprayed into the space in the upper portion of the reactor vessel. As the space is under negative pressure, oxygen existing in the water droplets of the sprayed coolant is separated. After completion of entire control rod insertion, a residual heat removal system is operated. The spraying operation is discontinued and a low-temperature coolant cooled by a heat exchanger in the residual heat removal system is sprayed into said space. The coolant sprayed by said first spraying operation is not cooled by the heat exchanger in said residual heat removal system.

Abstract: In order to remove carbon dioxide from an off-gas stream and immobilize it in solid stable form, the gas is passed through a packed bed of calcium hydroxide maintained at a temperature in the range 10.degree. C.-50.degree. C., the moisture content of the gas being controlled so as to correspond to a relative humidity from 40% to 100% at the bed temperature.

Abstract: A self-contained and movable device for collecting purge liquids and gases in an installation containing radioactive substances, comprising a detachable and transportable vessel (5) of small dimensions, a closure of the purge outlet (2) which can be operated from outside the vessel (5), a movable unit (7) for drawing off and collecting the purged liquids and gases, and a flexible tube (6) connecting the vessel (5) and the movable drawing-off and collecting unit (7). The invention applies particularly to the purging of the cooling circuit under shut-down conditions of a pressurized water nuclear reactor.

Abstract: This invention relates to monitoring the condition of a nuclear power generating facility and has particular applicability to isolating samples of primary coolant from a pressured water reactor to enable analysis in a post accident environment.

Abstract: A hydrogen removal system (10) separates hydrogen from the containment atmosphere of a nuclear power plant using a hydrogen permeable membrane separator (30). Water vapor is removed by condenser (14) from a gas stream withdrawn from the containment atmosphere. The gas stream is then compressed by compressor (24) and cooled (28,34) to the operating temperature of the hydrogen permeable membrane separator (30). The separator (30) separates the gas stream into a first stream, rich in hydrogen permeate, and a second stream that is hydrogen depleted. The separated hydrogen is passed through a charcoal adsorber (48) to adsorb radioactive particles that have passed through the hydrogen permeable membrane (44). The hydrogen is then flared in gas burner (52) with atmospheric air and the combustion products vented to the plant vent. The hydrogen depleted stream is returned to containment through a regenerative heat exchanger (28) and expander (60).

Abstract: Removal of small amounts of .sup.14 CO.sub.2, .sup.14 CO and corresponding alkanes produced in nuclear power plants from the exhaust gases of the purification plants by conversion of the radioactive compounds into .sup.14 CO.sub.2, and removing this .sup.14 CO.sub.2 from the main gas stream of exhaust gases.

Abstract: Nuclear reactor with a liquid coolant loop having a volume control surge tank for the coolant disposed in the loop, and a high pressure pump disposed in the loop for feeding coolant taken from the loop back into the loop after purification. A line bypassing the volume control surge tank and having an end connected to the suction side of the high-pressure pump, and a feed-in for introducing hydrogen into a liquid-filled section of the loop on the suction side of the high-pressure pump.

Abstract: A filter for the removal by the exchange effect of fission products from the coolant, generally helium, of a nuclear reactor comprises a gas-tight duct containing at least one coil of corrugated metal strip, the coil being formed from two strip layers whose corrugations are mutually crossing.

Abstract: Disclosed is an apparatus for detecting the location of failed fuel in a reactor, the apparatus comprising means for collecting tag gas from cover gas containing tag gas at ambient temperature and enriching the collected tag gas to an analyzable concentration and tag gas analysis means for analyzing the enriched tag gas to determine the composition thereof.

Abstract: A heat transfer system for a nuclear reactor. Heat transfer is accomplished within a sealed vapor chamber which is substantially evacuated prior to use. A heat transfer medium, which is liquid at the design operating temperatures, transfers heat from tubes interposed in the reactor primary loop to spaced tubes connected to a steam line for power generation purposes. Heat transfer is accomplished by a two-phase liquid-vapor-liquid process as used in heat pipes. Condensible gases are removed from the vapor chamber through a vertical extension in open communication with the chamber interior.