Abstract: 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.

Abstract: 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.

Abstract: 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.

Abstract: 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.

Abstract: 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.

Abstract: A grid for use in nuclear fuel assemblies is made up of double grid members which are deformed so as to provide channels for the coolant. At least the upper portions of these channels are inclined relative to the axes of the fuel rods and are disposed in such a manner as to cause circulation of fluid about each individual rod and within the assembly. In one embodiment the grid is positioned between the positioning grids and serves primarily as a coolant deflector. In another embodiment so constructed as to serve the positioning grid, as well as a flow deflector, the channels are straight in their lower portions i.e. parallel to the axes of the fuel rods. In their upper portions they curve to provide the desired deflection of the cooling fluid and the straight sections have a slight bow outward, relative to the plane of the grid member of which they are a part. This outwardly bowed portion engages the fuel rod and acts as a positioning spring.

Abstract: This invention is directed to a fuel assembly for boiling water reactors incorporating an advanced type of "water rod.

Abstract: A structural support system for the core of a nuclear reactor which achieves relatively restricted clearances at operating conditions and yet allows sufficient clearance between fuel assemblies at refueling temperatures. Axially displaced spacer pads having variable between pad spacing and a temperature compensated radial restraint system are utilized to maintain clearances between the fuel elements. The core support plates are constructed of metals specially chosen such that differential thermal expansion produces positive restraint at operating temperatures.

Abstract: An improved mixing vane grid spacer having enhanced flow mixing capability by virtue of mixing vanes being positioned at welded intersecting joints of the spacer wherein each mixing vane has an opening or window formed therein substantially directly over the welded joint to provide improved flow mixing capability. Some of the vanes are slotted, depending on their particular location in the spacers. The intersecting joints are welded by initially providing consumable tabs at and within each window, which are consumed during the welding of the spacer joints.

Abstract: A system for capturing a grid spacer in a nuclear fuel bundle which comprises a split sleeve fixed to a capture rod. The sleeve is used in conjunction with a grid spacer having openings formed by intersecting walls which include protrusions and coacting springs extending from the walls. The sleeve includes pairs of longitudinally spaced bosses and a standoff boss extending radially outward from the surface of the rod. The pairs of bosses are positioned astride the protrusions from the walls to prevent longitudinal movement of the grid spacer. The split serves as a guide slot to orient the capture rod so that it may pass through the grid spacer openings unencumbered by the protrusions from the grid space walls. The standoff boss is in surface contact with a wall of the grid spacer.

Abstract: A bimetallic grid spacer comprising a grid structure of zircaloy formed by intersecting striplike members which define fuel element openings for receiving fuel elements and spring strips made of Inconel positioned within the grid structure for cooperating with the fuel elements to maintain them in their desired position. A plurality of these spring strips extend longitudinally between sides of the grid structure, being locked in position by the grid retaining strips. The fuel rods, which are disposed in the fuel openings formed in the grid structure, are positioned by means of the springs associated with the spring strips and a plurality of dimples which extend from the zircaloy grid structure into the openings. In one embodiment the strips are disposed in a plurality of arrays with those spring strip arrays situated in opposing diagonal quadrants of the grid structure extending in the same direction and adjacent spring strip arrays in each half of the spacer extending in relatively perpendicular directions.

Abstract: An improved mixing vane grid spacer having enhanced flow mixing capability by virtue of mixing vanes being positioned at welded intersecting joints of the spacer wherein each mixing vane has an opening or window formed therein substantially directly over the welded joint to provide improved flow mixing capability. Some of the vanes are slotted, depending on their particular location in the spacers. The intersecting joints are welded by initially providing consumable tabs at and within each window, which are consumed during the welding of the spacer joints.

Abstract: A nuclear core arrangement for admitting reactor coolant into nuclear reactor fuel assemblies. Inlet nozzles having main and alternate inlets are attached to the fuel assemblies. Each of the nozzle inlets receive reactor coolant from a separate flow plenum. The flow plenums are arranged in parallel and are separated by a perforated sealing member. Should the main inlet to the fuel assembly become clogged by debris, the alternate inlet supplies the fuel assembly with reactor coolant.