Ab Asea-atom

Abb Atom Ab

Peter Fejes

Antti Suvanto

Roland Ivars

Eva Sundell

Eva Hallden

Particles of an ion exchange resin are brought into contact with water in a water circulation system in a power plant for capturing corrosion products and other impurities and are removed after reaction with the corrosion products and the other impurities from the water circulation system, the water circulation system including a reactor vessel or a steam generator connected thereto for generation of steam, a steam turbine driven by the steam, a condenser for condensing the steam from the steam turbine and a condensate cleaning filter for cleaning condensate formed in the condenser, as well as one or more pumps for effecting the water circulation and returning cleaned condensate to the reactor vessel or the steam generator. The ion exchange resin is supplied successively to the condensate in the water circulation system at a sufficient distance from the condensate cleaning filter for the ion exchange resin, when being collected in the form of layers in the condensate cleaning filter, to have been substantially exhausted by reaction with corrosion products and other impurities during the movement of the water from the supply point for the ion exchange resin to the condensate cleaning filter. The exhausted ion exchange resin collected in the condensate cleaning filter is removed after a certain period of collection from the condensate cleaning filter.

Method of removing corrosion products in a water circulation system

A layer of small-sized particles of an organic ion exchange resin is applied to a support matrix, permeable to liquid, of a filter element (7) which is arranged in a chamber (5) in an ion-exchange filter (1) for filtering of liquids containing radioactive constituents. The filter and a mixer (11), consisting of a tube with a number of stationary mixing elements arranged one after the other in the longitudinal direction of the tube, are arranged in a circulation system (10) for water. The mixing elements successively divide up a material flow, supplied at the inlet end of the mixer, into a number of sub-flows containing different parts of the original material flow and the sub-flows are reunited, before they reach the outlet end of the tube. Suspended ion-exchange resin (13a, 16a) is supplied to the inlet end (11a) of the mixer for the circulating water while the water is being circulated in the circulation system. A coating of the ion-exchange resin with predetermined and reproducible properties is obtained on each filter element.

Method of applying a layer of ion-exchange resin to a support matrix,

During local cleaning of metallic surfaces (15, 24) on parts included in the primary circuit of a nuclear reactor, which surfaces are coated with corrosion products, in connection with inspection of the surfaces, the coated surface, while being located below the surface of the reactor water (13) in the reactor vessel (10) or reactor pool (12) of the nuclear reactor, is arranged in contact with an electrolytically permeable spacer (16) of an electrically insulating material which, at a distance from the coated surface, is arranged in contact with a body (170 of electrically conductive material. An electrolyte (21) is supplied to the spacer and an electrical potential difference is maintained between the coated metallic surface and the body of conductive material by connecting the surface to the positive pole (18) and the body to the negative pole (19) of a voltage source (20).

Method for local cleaning of surfaces on a nuclear reactor which are

The water flowing in a nuclear reactor is analyzed, while the reactor is in operation, by conducting water from the reactor vessel substantially without reduction in pressure or temperature past test surfaces (e.g. tubes) with different electrochemical potentials relative to the reactor water. Deposits formed on the test surfaces, which are substantially caused by colloidal particles in the water, are examined, preferably with regard to radioactive content.

Method and a device for analyzing water in the primary circuit of a

An electrode (20) for electrochemical measurements in aqueous solutions at high temperatures, especially measurements in water in or from a primary or secondary circuit of a nuclear reactor in operation at a temperature of the water substantially prevailing at that time, comprises a conductor (21) of a platinum-group metal which for part of its extension is enclosed within a casing (22) making tight contact with the conductor and consisting of sintered-together particles of aluminum oxide, zirconium oxide or other electrically-insulating material which is inert to water. The conductor has one part (21a) exposed the aqueous solution and one connection part (21b) for connection to an electrical measuring member.

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Vaster.ang.s, Sweden

Peter Fejes