An electrochemical cell that oxidizes a solution provides a continuous and stable supply of an oxidizing ion solution to a fixture or vessel used for the purposes of decontaminating metal and metal alloys. The electrochemical cell includes an anode compartment that oxidizes the solution in nitric acid or methane sulfonic acid at a rate equal to or greater than a rate of reduction, or generates the oxidizing ions prior to use in a batch. The electrochemical cell is part of a larger system that facilitates online measurement system which measures the oxidizing ion solution and the dissolved PuO.sub.2, UO.sub.2, AmO.sub.2, other radionuclides, or other contaminates in real-time. Solution decontamination system removes the dissolved PuO.sub.2/UO.sub.2/AmO.sub.2, other radionuclides, or other contaminates from the oxidizing ion solution, real time acoustic monitoring of the thickness of the surface being contaminated, and automation of a delivery system facilitates flow between surface and electrochemical cell.

The invention provides electrochemical surface treatment apparatus (100) for the treatment of radioactively contaminated internal surfaces of a pipe (1). The apparatus (100) includes an electrode device (102). The device (102) includes an electrode (4), which, in use, is located in electrolyte liquid (2) within the pipe (1) adjacent a treatment surface (104) to be treated with a gap (106) defined between the electrode (4) and the treatment surface (104). The apparatus (100) includes a circulation arrangement (108). The electrode (4) defines an internal passage (110). In use, the circulation arrangement (108) causes a recirculating flow of electrolyte liquid (2) through the gap (106) in one direction and along the passage (110) in an opposite direction.

In a submersible ultrasonic cleaning system for use in highly radioactive environments (e.g., cleaning radiated nuclear fuel assemblies), a bond between energy producing transducers and an radiating wall is strengthened with a polyurethane adhesive such as Permabond PT326, or 3M DP-190 adhesive. In various diagnostic tests, one or more of the transducers are operated in an energy-transmitting mode while one or more other transducers are operated in an energy-detecting mode to detect a weakened transducer/wall bond and/or acoustic conditions of the working fluid.

A method of decontaminating metal surfaces in a cooling system of a nuclear reactor comprises: an oxidation step, comprising at least one acidic oxidation step and at least one alkaline oxidation step wherein metal oxides and radioisotopes on the metal surfaces are contacted with aqueous permanganate oxidant solutions; followed by a decontamination step wherein an aqueous solution comprising oxalic acid, formic acid, citric acid, tartaric acid, picolinic acid, gluconic acid glyoxylic acid or mixtures thereof is used to dissolve at least part of the metal oxides and radioisotopes; and a cleaning step wherein radioisotopes are immobilized on an ion exchange resin; wherein at least one treatment cycle includes a high temperature oxidation step, wherein the permanganate oxidant solution is kept at a temperature of at least 100 C.

This invention relates to compositions and methods for the at least partial dissolution, disruption and/or removal of deposit, such as scale and other deposit, from heat exchanger components. The heat exchanger components can include pressurized water reactor steam generators. In accordance with the invention, elemental metal is added locally to the surface of the deposit and/or anodic or cathodic current is applied locally to the deposit surface to destabilize or weaken the deposit. Subsequently, mechanical stress is applied to the weakened deposit to disrupt and remove the deposit from the surface of the heat exchanger component.

Electrolytic interior surface treatment apparatus (100) for the electrolytic treatment of an internal surface (102) of a metallic pipe (1) includes at least two oppositely polarised electrodes (3, 4). The apparatus (100) includes: an electrically insulating centralisation arrangement (106) to keep, in use, the electrodes (3, 4) centred within the pipe (1); and an electrically insulating flexible connection arrangement (104) located between the two electrodes (3, 4) to permit movement of one electrode relative to the other. The centralisation arrangement (106) includes a plurality of spaced apart centralisation devices (5, 6). Each centralisation device (5, 6) includes an electrically insulating mounting (7) for mounting the respective centralisation device (5, 6) to the apparatus (100). Each centralisation device (5, 6) includes a plurality of flexible elements (108), each of which is fixed to the mounting (7) and extends outwardly from the mounting (7).

A method of removing nuclear contamination from a surface comprising applying a DC-biased AC waveform in an electro-pickling process using nitric acid as the electrolyte.

A device for submersibly cleaning surfaces inside a nuclear reactor includes a pump and a nozzle connected to said pump. The nozzle is arranged to face surfaces to be cleaned. The device includes cleaning means capable of removing debris on surfaces to be cleaned. The device includes adjustable flotation means, capable of adjusting the flotation capability of the device depending on a type of cleaning application.

A cleaning device includes an external casing (1) forming a suction hood and an upper suction mouth (2) and being provided with drive arrangements arranged on each side and equipped with independent motors and corresponding transmission mechanisms on each side; and cleaning rollers (51, 52, 53, 54); sets of internal cleaning rollers (53, 54) disposed close to the center of the hollow interior of the casing (1) and having a width approximately equal to the distance between the side elements (11) of the casing (1); sets of external cleaning rollers (51, 52) located close to the front and rear edges of the casing (1) of the cleaning device and having a total width slightly greater than the width of the casing; a resilient joint at the support for the external rollers; an adhesion turbine, a suction turbine, and auxiliary drive wheels on the internal cleaning rollers.

A method for treating waste water from the decontamination of a metal surface in a primary coolant circuit of a nuclear reactor comprises discharging a predetermined amount of an oxidation solution from the primary coolant circuit into a reduction zone connected to the primary coolant circuit and reacting the oxidation solution with a reducing agent to form a reaction solution that is freed of oxidizing agent, and passing the reaction solution over an ion-exchange resin in order to form a desalinated solution, and returning the desalinated solution to the primary coolant and/or disposing of the desalinated solution. A waste water treatment apparatus for carrying out the method is also provided.