Westinghouse Electric Corporation

The United States of America As Represented by the Department of Energy

Thomas G Bengel

Phillip E Miller

Frank I Bauer

Gary J Corpora

Robert G Aspden

James Sejvar

John F Remark

Robert E Meuschke

Richard E Kothmann

Robert B Salton

James S Schlonski

Robert S Mavretish

Noel P Grimm

Elwyn L Cranford, Iii

Raymond J Nath

Edward A Ray

Robert M Roidt

David R Peffer

Dan H Dixon

In a method of decontaminating a primary loop of a pressurized water reactor, including a steam generator, reactor coolant pump and hot and cold legs in the loop, the primary loop is isolated from a nuclear reactor vessel by closing hot leg and cold leg loop stop valves. Decontamination process water is circulated from one side of the steam generator channel head to the other side of the channel head via a bypass pipe extending between the cold leg and the hot leg without bypassing the water through steam generator tubes extending between the sides of the channel head. The level of the decontamination water in the steam generator is maintained at two to three feet in the tubes.

Method of decontaminating a PWR primary loop

An automated method for maintaining pressure within a nuclear power plant primary loop during either startup or shutdown, the method comprises the steps of partially filling a portion of a pressurizer vessel, in fluid communication with the primary loop, with a liquid for maintaining pressure in the primary loop; circulating a primary coolant through the primary loop; automatically injecting an inert gas by a first automated device, operatively connected to the pressurizer, into the pressurizer vessel when the pressure in the pressurizer vessel is less than a first predetermined pressure; and automatically venting the gas by a second automated device, operatively connected to the pressurizer, from the pressurizer vessel when the pressure in the pressurizer vessel is greater than a second predetermined pressure.

Method and system for maintaining pressure in a nuclear power plant

A nuclear reactor having a chemical decontamination clean-up system is provided in which every component of the chemical decontamination clean-up equipment which processes radioactive fluids is located within a shielded room of an existing on-site support building. Those components of the clean-up system not in direct contact with radioactive fluids are housed in portable trailers. The decontamination clean-up system is designed to provide for adequate shielding to minimize personnel exposure and also incorporates a modular design for component transportation and storage.

Nuclear reactor primary system chemical decontamination clean-up system

An arrangement of reactor coolant pump seals arranged in a generally annular stack with a plurality of stacking spacers in a test housing for emplacement in a chemical decontamination test loop enables a variety of flow characteristics to be simulated by varying the detailed arrangement of the RCP seals and supporting structure in the test housing. By adjusting parameters such as fluid chemistry, gross flow, pressure, and temperature in a controlled manner with systems incorporated into the test loop, additional information can be obtained regarding the feasibility of any specific decontamination process. The magnitude of process fluid flow across particular surfaces of one or more RCP seal components can be predetermined by selecting the placement, number and dimensions of penetrations in a flow distribution tube through which the process fluid enters the housing. The penetrations feed the process fluid to channels in selected stacking spacers, thereby directing the process fluid flow to selected seal surfaces. The arrangement of the stacked seal assembly also assures that each of the seal components will experience a process fluid flow similar to what would be experienced in an in situ decontamination procedure in an RCP.

Reactor coolant pump seal test decontamination housing

A tank is disclosed for containing a liquid in which control rod drive shafts of a nuclear power plant are stored. The tank comprises a lower tank portion having a bottom and a tank wall extending outwardly from the bottom for defining a lower storage cavity of the tank. An upper tank portion having walls is removably attached to the lower tank portion for defining an upper storage cavity of the tank. A plurality of tubes are arranged in the lower tank portion for adaptably receiving the shafts for storage.

Apparatus for storing control drive rod shafts during chemical

A chemical decontamination clean-up system for use on-line in a nuclear reactor primary system includes a pump arrangement within the nuclear reactor primary system for pumping primary system fluids to a cleaning system located directly downstream from the pump assembly. The cleaning system includes a plurality of first demineralizer banks arranged in a predetermined flow pattern for receiving the primary system fluids. Each of the first demineralizer banks comprises at least two individual, resin-filled demineralizers arranged in parallel wherein primary system fluids are demineralized. Each of the demineralizer banks includes valving for selectively directing the primary system fluids from the pump arrangement to selected demineralizer banks in the plurality of the first demineralizer banks. A second demineralizer bank receives the primary system fluids from the plurality of first demineralizer banks. The second demineralizer bank includes at least two individual, resin-filled demineralizers arranged in parallel wherein primary system fluids are 'finish' demineralized. A return system receives the primary system fluids from the second demineralizer bank and directs the fluids back to the nuclear reactor primary system. The return system includes at least one trap for receiving the primary system fluids from the second demineralizer bank and operable to remove resin suspended in the primary system fluids, and at least one filter downstream from the trap for removing solids suspended in the primary system fluids prior to the return of the fluids to the nuclear reactor primary system.

Clean-up system for the chemical decontamination of a nuclear reactor

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.

Process for decontaminating a nuclear reactor coolant system

A crack propagation test specimen has a base metal and a clad metal. The base metal has an upper surface and a bottom surface with a hole extending from the bottom surface toward the upper surface. The cladding metal is supported on the upper surface of the base metal and has a first slot cut therethrough which is in fluid flow communication with the hole in the base metal. A second slot is cut in the cladding metal adjacent to the first slot for receiving a wedge. The first slot and the second slot define a wall which closes over the first slot when a wedge is forced into the second slot to simulate a hairline crack. A mechanically deformed metal sample is disposed in the hole in the base metal to simulate a stressed base metal supporting a cladding metal subject to hairline cracking.

Crack propagation test specimen

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.

Alkaline-permanganate process

A test specimen for evaluating crack propagation and associated wear and corrosion on cladded piping is provided. The test specimen simulates the hairline crack conditions found on the inner cladding layer of a piping system. The test specimen is useful in analyzing the effects that a certain process fluid has on an exposed cracked cladding layer surface.

Test specimen for evaluating crack propagation due to corrosion

Process for evaluating crack propagation due to corrosion

A unique and optimal method for assessing the feasibility of employing chemical decontamination processes to remove crud from nuclear reactor primary systems without adversely affecting the integrity of the system components or piping during further reactor operation is disclosed. Materials used to construct such components and piping are exposed to several cycles of simulated decontamination processing with a test loop constructed to simulate a range of full system decontamination process conditions. The material specimens are then removed and tested to assure that the particular decontamination processing system has no adverse effects on the materials used.

System for qualification of chemical decontamination methods for

A temperature monitoring device for measuring the temperature at a surface of a body, composed of: at least one first thermocouple and a second thermocouple; support members supporting the thermocouples for placing the first thermocouple in contact with the body surface and for maintaining the second thermocouple at a defined spacing from the body surface; and a calculating circuit connected to the thermocouples for receiving individual signals each representative of the temperature reading produced by a respective one of the first and second thermocouples and for producing a corrected temperature signal having a value which represents the temperature of the body surface and is a function of the difference between the temperature reading produced by the first thermocouple and a selected fraction of the temperature reading provided by the second thermocouple.

Temperature monitoring device and thermocouple assembly therefor

System and method for abrading radioactive contaminants from the inside surface of a pipe. The system includes a nozzle block capable of mixing a liquid and an abrasive grit into a suitable liquid-abrasive grit cleaning composition and impinging the cleaning composition against the inside surface of the pipe. The system further includes an inflatable torus-shaped seal for confining the liquid-abrasive grit cleaning composition to a predetermined portion of the inside surface of the pipe so that substantially all of the contaminants and cleaning composition can be suitably vacuumed from the surface.

Growing community of inventors

Plum Borough, PA, United States of America

Thomas G Bengel