Abstract: In a PFC decomposing apparatus according to the present invention, PFC contained in a discharged gas is decomposed in catalyst cartridge 3 packed with a catalyst containing 80% Al2O3 and 20% NiO. The discharged gas containing acid gases as a decomposition gas is cooled in cooling chamber 6 and led to discharged gas washing column 13, where the acid gases are removed. Mists of acid gases (SO3 mists or NOx mists) entrained in the discharged gas are separed in cyclone 16. Compressed air at about 0.1 Mpa is fed to ejector 24 through air feed pipe 56. The interior of ejector 24 is brought into a negative pressure state by the compressed air to such the discharged gas from cyclone 16 and ejector. Ejector 24 can reduce a frequency of maintenance inspection, as compared with a blower.

Abstract: In order to prevent exhaust pipe for exhausting perfluorocompound (PFC) decomposition gas after washing from corrosion, a mist separating apparatus is provided at a rear stage of the washing tower for washing the PFC decomposition gas. The corrosion of the exhaust pipe can be prevented by removing the mist from the washed gas.

Abstract: An exhaust gas containing a perfluoride component (PFC) and SiF4 is conducted into a silicon remover and brought into contact with water. A reaction water supplied from a water supplying piping and air supplied from an air supplying piping are mixed with the exhaust gas exhausted from the silicon remover. The exhaust gas containing water, air, and CF4 is heated at 700° C. by a heater. The exhaust gas containing PFC is conducted to a catalyst layer filled with an alumina group catalyst. The PFC is decomposed to HF and CO2 at a high temperature exhausted from the catalyst layer is cooled in a cooling apparatus. Subsequently, the exhaust gas is conducted to an acidic gas removing apparatus to remove HF. In this way, the silicon component is removed from the exhaust gas before introducing the exhaust gas into the catalyst layer. Therefore, the surface of the catalyst can be utilized effectively, and the decomposition reaction of the perfluoride compound can be improved.

Abstract: A gas stream containing at least one fluorine compound selected from the group consisting of compounds of carbon and fluorine, compounds of carbon, hydrogen and fluorine, compounds of sulfur and fluorine, compounds of nitrogen and fluorine and compounds of carbon, hydrogen, oxygen and fluorine is contacted with a catalyst comprising at least one of alumina, titania, zirconia and silica, preferably a catalyst comprising alumina and at least one of nickel oxide, zinc oxide and titania in the presence of steam, thereby hydrolyzing the fluorine compound at a relatively low temperature, e.g. 200°-800° C., to convert the fluorine of the fluorine compound to hydrogen fluoride.

Abstract: A treating apparatus for decomposing organohalogen compounds such as chlorofluorocarbons (CFC's), trichloroethylene, methylbromide, halon, and the like, effectively, with a high activity of catalyst, is provided. The apparatus includes a reactor in which organohalogen compounds are decomposed by contact at a temperature in a range of 200.degree..about.500.degree. C. with a catalyst which comprises titania and tungsten oxide by an atomic ratio of Ti and W in a range from 20 mol % to 95 mol % Ti and from 5 mol % to 80 mol % W, with at least the surface of the titania being covered with a porous layer of the tungsten oxide. In accordance with the present invention, organic compounds containing any of fluorine, chlorine and bromine will be decomposed with a high efficiency, and the activity of the catalyst can be maintained for a long time.

Abstract: SF.sub.6 gas is collected from the inside of a gas insulated machine during maintenance and inspection and is refined. Compositions of the refined SF.sub.6 gas are analyzed and confirmed to be reusable at the site. In the process of SF.sub.6 gas collecting and refining, acidic gases are neutralized and removed by a dry method using filters and the refined SF.sub.6 gas is collected in a collecting tank. In particular, after the refining, the composition of the collected SF.sub.6 gas is measured and confirmed by analysis equipment to quantitatively confirm whether or not the refined SF.sub.6 gas is reusable.

Abstract: A process is provided for the destruction of organohalogen compounds, such as methyl chloride, chloroform, carbon tetrachloride, etc., by mixing the organohalogen compounds with a heated carrier gas, such as nitrogen, argon or air, and either steam or water to form a mixture; supplying the mixture to a catalyst, such as titanium oxide/tungsten oxide, to decompose the organohalogen compounds into halogens and hydrogen halides, such as chlorine, hydrochloric acid, fluorine and hydrofluoric acid; conducting the halogen and hydrogen halide contaminated gas through a bent path, created by a baffle that prevents the entry of mist or droplets into the catalyst chamber, into a cooling section where the halogen and hydrogen halide contaminated gas is sprayed with water to cool the gas to a temperature low enough to prevent the formation of dioxines. An alkaline agent, such as sodium hydroxide, can be added to the cooling water to neutralize the halides and hydrogen halides.

Abstract: A method for treating a gas flow containing organohalogen compounds including the steps of contacting the gas flow with a catalyst at a temperature below 500.degree. C. in the presence of an effective amount of steam, wherein the catalyst contains titania, tungsten oxide, and silica, the Ti and W are present in the range of 20-95 mol % Ti and 5-80 mol % W based on Ti and W, and the amount of silica is in the range of 0.5-15% by weight silica to 100% by weight titania. Accordingly, the organohalogen compound can be decomposed effectively to carbon monoxide, carbon dioxide, and hydrogen halide.

Abstract: A treating method for decomposing organohalogen compounds such as chlorofluorocarbons (CFC), trichloroethylene, methyl bromide, halon, and the like, effectively, with a high activity of catalyst is provided.Organohalogen compounds are decomposed by contacting at a temperature in a range of 200.degree..about.500.degree. C. with catalyst which comprises titania and tungsten oxide by an atomic ratio of Ti and W in a range from 20 mol % to 95 mol % Ti and from 5 mol % to 80 mol % W, and at least surface of the titania is covered with porous layer of tungsten oxide.In accordance with the present invention, organic compounds containing any of fluorine, chlorine, and bromine can be decomposed with a high efficiency, and the activity of the catalyst can be maintained for a long time.

Abstract: An object of the present invention is to improve retainability (distribution coefficient) for C-14 of a radioactive waste solidified body. The waste is solidified with a solidification agent containing a soluble substance which yields an insoluble substance by a reaction with carbonic ions, insoluble carbonates, or a mixture of the above substances. And, as for a pre-treatment, the soluble substance which yields an insoluble substance by a reaction with carbonic ions is previously reacted with liquid waste, and subsequently the solidification is performed. The retainability (distribution coefficient) for C-14 of the solidified body of the waste increases about one order.

Abstract: A processing system for radioactive waste is composed of an adjusting tank having a sampling port, a solidification processing system, and a package inspection apparatus, and a package, of which inventory per a package has been exactly grasped, is prepared by solidification of the waste with the processing system after determining radioactivity of the waste by measurement before the solidifying process.In accordance with the present invention, data on radioactivity before and after preparation of package of waste become clear, and management of each package at transportation and intermediate storage of the packages is facilitated.

Abstract: Objective of the present invention is to provide a preferable solidified body ensuring performance of artificial barrier in a solidifying process for incombustible miscellaneous solid waste and other wastes such as calcined ashes by preventing generation of hydrogen gas by a reaction of amphoteric metal included in the waste with solidifying materials.In order to suppress the reaction of the amphoteric metal with the solidifying materials, any one or arbitrary plurality of the following three means are provided in the solidifying materials;(1) A means for forming protection film on surface of the amphoteric metal,(2) A means for enhancing hydration reaction of cement,(3) A means for reducing basicity of the solidifying materials.In accordance with the present invention, a preferable solidified body can be obtained by a simple and easy method which does not necessitate separation and pre-treatment of the waste.

Abstract: A radioactive waste liquid treatment apparatus according to the invention comprises an upstream-side filter unit having an inlet for radioactive waste liquid, and a downstream-side filter unit communicating with the upstream-side filter unit and having an outlet for filtrated liquid. Further, the upstream-side filter unit includes first filter member installed therein having active silica for removal of interfacial active agents and oil, whereas the downstream-side filter unit includes second filter member installed therein, and this second filter member has a vapor permeable membrane.

Abstract: A method of solidifying a radioactive waste of an atomic power plant, for example, begins with concentrating the liquid waste to powder or pellet form to reduce its volume. Prior to reducing its volume, an estimation is made of what the concentration will be once the liquid waste is converted into powdered or pelletized form. The powdered or pelletized waste is charged into a container, and a solidifying agent is poured over the contents to form a solidified body. The solidifying agent is prepared to have a desired coefficient of distribution that is determined in accordance with the estimated concentration of the reduced volume solidified waste so that the amount of leaching of the solidified body that is produced will be less than or equal to a predetermined value, such as the known value of leaching for a conventional cement-solidified waste that is not processed to reduce its volume before being solidified.

Abstract: The present invention provides drying and pulverization of a radioactive liquid waste containing sodium borate as a main component by heating, where the liquid waste is heated, dried and pulverized to substantially crystalline, homogeneous powder of sodium borate while suppressing occurrence of a foaming phenomenon of the powder. The susbtantially crystalline powder is obtained by heating, drying and pulverizing the liquid waste at a temperature outside the temperature range where the salt powder takes an amorphous state in the course of releasing water of crystallization from the salt powder. In the drying and pulverization of a liquid waste containing sodium borate by a thin film evaporator, occurrence of the foaming phenomenon can be suppressed by maintaining the temperature on the heat transfer surface of the evaporator at a temperature lower than 150.degree. C.

Abstract: A soluble salt (sodium sulfate or sodium borate (Na.sub.2 SO.sub.4 or Na.sub.2 B.sub.4 O.sub.7) contained as the main component in a concentrated radioactive waste liquid generated in the BWR power plant or the PWR power plant is insolubilized and precipitated, sodium hydroxide (NaOH formed in the insolubilization is separated from the precipitate and the radioactive waste liquid slurry containing the precipitate is solidified with a hydraulic solidifying material. Since the separated caustic soda (NaOH) is free of radioactive substances, it can be easily utilized again, and since the radioactive substances are stably fixed in the solidified body, leakage of radioactivity from the solidified body can be greatly reduced.

Abstract: The present invention relates to a method and an apparatus for producing a waste package of radioactive waste containing particles of radioactive waste material of low modulus of elasticity, particles of radioactive waste material of high modulus of elasticity, and a solidifying agent in which the particles of radioactive waste material of low modulus of elasticity and the particles of radioactive waste material of high modulus of elasticity are fixed in an almost uniformly dispersed state. According to this invention, the radioactive waste generated from nuclear power plants can be greatly reduced in volume and also a waste package of radioactive waste with high strength and excellent water resistance can be obtained.

Abstract: A method of and apparatus for pelletizing a radioactive waste powder is disclosed. The apparatus includes a pelletizing section, and a pelletizing die which has one end facing a powder receiving cavity formed in the pelletizing section and the other end exposed to the atmosphere, and a through bore is so formed in the die as to pass from the one end to the other end. A first pelletizing rod can be inserted into and pulled out of the through bore from the one end of the die through the cavity, and a second pelletizing rod can be inserted into a pulled out of the through bore from the other end of the die. The first and second rods are arranged such that, when the second rod takes a predetermined position in the through bore, the first rod is inserted through the receiving cavity into the through bore, thereby enabling the pelletizing operation of the powder within the through bore.

Abstract: This invention relates to a method of processing radioactive waste, comprising the steps of converting organic radioactive waste into inorganic waste, pulverizing the inorganic waste, and solidifying the pulverized product with an inorganic hardening agent. According to the present invention, a solidified body having money-saving characteristics and a high volume reducing effect and capable of standing all kinds of weather condition excellently for a long period of time can be obtained.

Abstract: Radioactive waste is first converted into hardly water-soluble powder (including a water-insoluble powder) and then solidified with a hydraulic solidifier in a solidification vessel. The radioactive waste may be powdered (including granulated and encapsulated) by incorporating the radioactive waste with a substance which is capable of reacting with the water-soluble salt contained in the radioactive waste to form a hardly water-soluble salt (including a water-insoluble salt) and then powdering the mixture with drying, or by powdering the radioactive waste with drying, granulating the powder with drying and then microencapsulating the granules with a hardly water-soluble substance (including water-insoluble substance). The hardly water-soluble salts are preferably calcium salts, and the additives are preferably calcium hydroxide solution or solvent of combination of dichloromethane solution and hexane.