Advanced Nuclear Fuels Corporation

Siemens Power Corporation, Inc.

Exxon Nuclear Company, Inc.

Other

Exxon Research and Engineering Company

John F Patterson

Jack Yates

Richard H Ewing

George C Cooke

Barney S Flora

Charles A Brown

Kirk P Galbraith

Trond A Bjornard

Richard R Rosinski

Rolf Holzer

Robert B Macduff

Raymond A Busch

Wayne A VonOlnhausen

Robert I Rosenthal

Lorraine Figueroa

James T Britton

Peter P King

The present invention provides a fuel rod for a light water nuclear reactors that comprises a part-length fuel rod and an extension tube having at least one wall member defining an enclosed flow path therethrough, the extension tube being coupled to a portion of the part-length fuel rod so as to be disposed axially above the part-length fuel rod, and including at least one inlet opening, for allowing fluid that surrounds the rod and initially comprises a two phase mixture of steam and liquid, to enter the enclosed fluid path and at least one outlet opening located above the inlet opening, the extension tube includes means for separating at least some of the steam located in the fluid from the liquid located therein. The improved fuel rod allows steam to bypass the upper active portions of the fuel assembly. A coolant diverter is positioned in a spacer of a nuclear fuel rod assembly in the large subchannel above a part length fuel rod for increasing the hydraulic resistance of the large subchannel and for separating liquid from two phase flow.

Nuclear fuel rod assembly apparatus

An improved fuel rod is provided having a part-length fuel rod portion that improves performance with respect to typical part-length fuel rods without significant degradation of the benefits that are achieved by using such a system, e.g., improved fuel utilization, stability, and shut down margin. The present invention provides a fuel rod for a light water nuclear reactors that comprises a part-length fuel rod and an extension tube having at least one wall member defining an enclosed flow path therethrough, the extension tube being coupled to a portion of the part-length fuel rod so as to be disposed axially above the part-length fuel rod, and including at least one inlet opening, for allowing fluid that surrounds the rod and initially comprises a two phase mixture of steam and liquid, to enter the enclosed fluid path and at least one outlet opening located above the inlet opening, the extension tube includes means for separating at least some of the steam located in the fluid from the liquid located therein. The improved fuel rod allows steam to bypass the upper active portions of the fuel assembly. A hydraulic resistance strip having a predetermined amount of an axially distributed resistance surface is positioned above a part length fuel rod to achieve a more uniform distribution of hydraulic resistance in order to limit cross-flows from and between adjacent subchannels while maintaining most of the increase in fuel assembly flow area that is associated with the open space above the part length fuel rod.

Hydraulic resistance strip for a light water reactor

An improved fuel rod is provided having a part-length fuel rod portion that improves performance with respect to typical part-length fuel rods without significant degradation of the benefits that are achieved by using such a system, e.g., improved fuel utilization, stability, and shut down margin. The present invention provides a fuel rod for a light water nuclear reactors that comprises a part-length fuel rod and an extension tube having at least one wall member defining an enclosed flow path therethrough, the extension tube being coupled to a portion of the part-length fuel rod so as to be disposed axially above the part-length fuel rod, and including at least one inlet opening, for allowing fluid that surrounds the rod and initially comprises a two phase mixture of steam and liquid, to enter the enclosed fluid path and at least one outlet opening located above the inlet opening, the extension tube includes means for separating at least some of the steam located in the fluid from the liquid located therein. The improved fuel rod allows steam to bypass the upper active portions of the fuel assembly. A nuclear fuel rod for a light water reactor having a part length fuel rod and a reflex upper end fitting which functions to separate the liquid and vapor steam portions of two phase flow.

Coolant vent fuel rod and part length fuel rod having a reflex upper end

An improved fuel rod is provided having a part-length fuel rod portion that improves performance with respect to typical part-length fuel rods without significant degradation of the benefits that are achieved by using such a system, e.g., improved fuel utilization, stability, and shut down margin. The present invention provides a fuel rod for a light water nuclear reactors that comprises a part-length fuel rod and an extension tube having at least one wall member defining an enclosed flow path therethrough, the extension tube being coupled to a portion of the part-length fuel rod so as to be disposed axially above the part-length fuel rod, and including at least one inlet opening, for allowing fluid that surrounds the rod and initially comprises a two phase mixture of steam and liquid, to enter the enclosed fluid path and at least one outlet opening located above the inlet opening, the extension tube includes means for separating at least some of the steam located in the fluid from the liquid located therein. The improved fuel rod allows steam to bypass the upper active portions of the fuel assembly.

Coolant vent fuel rod for a light water reactor

A low pressure drop spacer for positioning and retaining the fuel rods of a nuclear fuel assembly in which a plurality of upper and lower spring forks which extend through apertures in the side wall of the spacer into the assembly and through apertures in grid members which divide the assembly. The intersection and superposition of the spring forks, side wall and grid members form fuel rod passageways through which the fuel rods extend.

Low pressure drop spacer for nuclear fuel assemblies

A boiling water reactor fuel rod assembly is provided having a plurality of fuel rod spacers which are slidably receivable within an outer channel. Each of the rod spacers is formed of at least one lattice which defines a plurality of fuel rod retaining cells. The lattice is constructed of a plurality of pairs of oppositely facing springy support strips, with each support strip having a plurality of spring-loaded indentations. In an unloaded condition, oppositely facing indentations of each pair of strips, which define each cell, are displaced closer to one another. In a loaded condition, the oppositely facing cell indentations are forced away from each other by the fuel rods so that the springloaded indentations support and retain the fuel rods.

Boiling water reactor fuel rod assembly with fuel rod spacer arrangement

A fuel assembly for a boiling water nuclear reactor is provided comprising an elongated central water channel including wall members that define an enclosed fluid flow path therethrough, the channel includes a lower opening for receiving water and allowing water to flow through the fluid flow path and at least one outlet opening. At least one partial water rod is provided that is coupled to a partial fuel rod so as to be disposed axially above the partial fuel rod. The partial water rod includes an inlet opening in fluid communication with the outlet opening of the central water channel so as to allow water to flow from the water channel into an interior of the partial water rod.

Fuel assembly for boiling water reactors

A grid spacer for a nuclear reactor fuel assembly is formed of two superposed combs. Each comb has a base strip which extends the width of the assembly. To it are attached parallel grid strips which are free at their other ends. The grid strips are perpendicular to the base strip and are formed for spring engagement with the fuel rods of the assembly. The combs can be inserted from the sides of the assembly, so that an additional or substitute spacer can be added to the assembly without disassembling the latter.

Side insertable spacer

A debris screen for a fuel assembly for a reactor to which coolant fluid is supplied comprises a substantially planar plate member having an array of coollant openings extending through the plate member dimensioned to trap at least a portion of debris particles carried by the coolant; and a skirt member enclosing the periphery of the plate member; each of the coolant flow openings having a coolant entry region at a lower surface, a coolant exit region at an upper surface and a coolant flow path extending between the entry and exit regions, the flow path including an intermediate segment laterally offset from the entry and exit regions to cause coolant to change direction of flow in the intermediate segment and thereby prevent at least a portion of the debris particles from passing through the plate members.

Fuel assembly debris screen

A spring member is formed of at least two layers metallurgically bonded together uniformly and having significantly different rates of irradiation growth, so that the differential growth of the layers results in increased stress in a predetermined direction. The layers may be of different metals or of similar metals which have been treated to give them different growth rates, such as zircaloy with different tin and oxygen content. Examples of other properties which may be used to obtain differential growth rates for the two layers when they are of material with substantially the same constituents are alpha-beta phase transformation temperature, the annealing temperature, the work history, partial recrystallization, and precipitation hardening.

Bimetallic spring member for radiation environment

An intermediate mixing grid for nuclear reactor fuel assemblies is made without the usual perimeter strip. The ends of the grid members are formed so that they hold the fuel rods at the edges of the assembly in place.

Intermediate mixing grid

A fuel assembly for nuclear reactors which comprises the usual upper and lower tie plates and fuel rods extending between them is made debris-resistant by providing a grid spacer in contact, or very nearly so, with the lower tie plate and so positioned as to subdivide the usual openings in the lower tie plate which are provided for the passage of cooling water. This causes debris to be trapped in the openings of the lower tie plate, and keeps it from contacting the fueled portion of the assembly.

Debris-resistant fuel assembly

A fuel assembly for boiling water reactors includes, in addition to the usual outer flow channel which surrounds the fuel rods, an inner flow channel having rectilinear sides disposed within the fuel assembly, extending vertically therethrough, and arranged to receive cooling water at or below the bottom of the assembly. The channel is of such size as to span several cooling rods in each direction. A closure is provided in the channel within the critical heat flux zone of the assembly. At least one inner tube extends through the closure. The channel is closed at its upper end, and the inner tube is open at its upper end, which is located near the upper end of the channel. Egress openings are provided in the walls of the channel just above the closure. These openings are so positioned relative to the fuel tubes that jets of water emitted from them do not impinge directly on the fuel tubes, but rather enter the flow spaces between them. Other egress openings are provided in the walls of the channel below the closure.

Bwr assembly

A user-application program for computerized telephone ordering is generated y a system designer who selects and interconnects pre-defined program modules and subroutines using a graphics terminal. The application program allows TOUCH-TONE input data and voice response. The present invention describes a Dialog Production System (DPS) for generating application programs for instructing a computer-controlled voice response system to provide computer-controlled voice services. The DPS includes interaction modules, each defining a basic end-user transaction which can be performed by the system, and methods for specifying module interconnection. Each interaction module controls the intercommunications with other modules and controls the devices which interface to the system. To design a dialog program to implement the desired voice service the system designer uses a graphic terminal to select and interconnect the modules to define the sequence of transactions needed to implement the desired voice service.

Method and apparatus for generating computer-controlled interactive

A marked reduction in the pressure drop of cooling liquid through a grid spacer of a nuclear fuel assembly is attained by convexly contouring the upstream (usually the lower) edges of the grid members. Preferably, they are made streamlined or semicylindrical. This can be done by first beveling and then etching them, by directing a stream of mixture of abrasive and an organic polymer against them, or by traversing an electron or laser beam along them at a power and velocity such as to cause local melting. A lesser improvement is secured by beveling alone. A still further improvement can be obtained by also tapering the downstream (usually upper) edges.

Growing community of inventors

Richland, WA, United States of America

John F Patterson