Abstract: The present invention provides a method of removing sludge deposits from steam generator/boiler tube support plates (TSP) using a combination of thermal stress and intermittent pressure pulses wherein the steam generator/boiler is drained to a water level just above a TSP identified as having excessive sludge deposits and/or particularly nonporous sludge known as collars and both thermal stress and high impact pressure pulses are used to dislodge the sludge and/or the collars with the process being repeated for all such TSP and the residue then flushed out by draining or using water lancing methods.

Abstract: A method is provided for cleaning crevices between a plurality of tubes and a plurality of tube support plates supporting the tubes in a steam generator. The steps include filling a secondary side of the steam generator with a solvent to a first level above a first tube support plate to be cleaned, draining the solvent to a second level lower than the first tube support plate, and refilling the secondary side of the steam generator with the solvent to a third level above the first tube support plate. A cleaning system is also provided.

Abstract: A steam generator chemical cleaning system is provided wherein a concentrated chemical cleaning solution is premixed off-site in sufficient volume and concentration to allow the dilution to proper cleaning level be achieved by slow injection into the generator when filled with demineralized water. The premixed chemicals are transported in a tanker to the generator site and injected therein directly from the tanker.

Abstract: A Nuclear Steam Supply Stem (NSSS) Mode 5 Steam Generator Chemical Cleaning system is disclosed which applies chemical cleaning solvent (formulated to remove SG deposits) to the secondary side of the SG using primary side supplied heat during NSS Mode 5 shutdown to maintain the desired application temperature. Mixing is achieved via nitrogen sparging.

Abstract: High velocity reactor coolant water in a boiling water reactor or a pressurized water reactor transports radioactive ions and particles from a nuclear reactor vessel to the balance of the reactor coolant system where they deposit on chromium (III) oxide-containing surfaces. These radioactive deposits are removed in a dilute chemical decontamination process wherein permanganate ion-containing reactor coolant water is circulated throughout a reactor coolant system to oxidize chromium (III) oxide surfaces of the system to chromium (IV) oxide. Formic acid is added to the permanganate ion-containing reactor coolant water and then the formic acid-containing water is circulated throughout the reactor coolant system to reduce unreacted permanganate ions in the reactor coolant water to manganous ions.

Abstract: An alkaline-permanganate process for chemically decontaminating oxidized metal surfaces wetted by primary water circulating in cooling loops of nuclear reactors maintains permanganate-containing primary water at a temperature of about 90.degree. C. and at a pH of 9-12 to oxidize the wetted surfaces. Oxalic acid is then added to the water and the oxalic acid-containing primary water is maintained at a temperature of at least about 90.degree. C. and at a pH of about 5-7 while it is circulated to destroy the permanganate ions and manganese dioxide.