Moderator control apparatus for a nuclear reactor fuel assembly

Patent · Tue Apr 14 04:00:00 EDT 1987

OSTI ID:6462184

Lancaster, D B; De Mario, E E

This patent describes a fuel assembly for a nuclear reactor including an organized array of upstanding fuel rods, a number of elongated guide thimbles strategically located within the fuel rod array, and a moderator/coolant flowing upwardly along the fuel rods to above the fuel assembly. An apparatus to control the nuclear reactivity is described for improving fuel utilization and thereby reducing fuel cycle costs. The control apparatus comprises: (a) hollow displacer rods inserted into respective ones of the guide thimbles, displacing a predetermined volume of the moderator/coolant associated with the fuel rods to decrease the hydrogen/uranium ratio from a given level; (b) a manifold disposed on the top of the fuel assembly in fluid flow communication with the moderator/coolant and having inlet ports and exit ports connected to and in fluid flow communication with respective ones of the displacer rods. Each inlet port is in fluid flow communication with at least one of the exit ports; and (c) valve means operably associated with the manifold inlet ports for controlling the flow and non-flow of the moderator/coolant through the inlet ports and into the displacer rods via the exit ports of the manifold. The flow of the moderator/coolant through the inlet ports and into the displacer rods increases the moderator/coolant volume in thereby shifting the hdyrogen/uranium ratio back to its given level.

• Assignee: Westinghouse Electric Corp., Pittsburgh, PA
• Patent Number(s): US 4657726
• OSTI ID: 6462184
• Country of Publication: United States
• Language: English

Related Subjects

22 GENERAL STUDIES OF NUCLEAR REACTORS
220300 -- Nuclear Reactor Technology-- Fuel Elements
220400* -- Nuclear Reactor Technology-- Control Systems
ACTINIDES
CONTROL ELEMENTS
CONTROL EQUIPMENT
COOLANTS
COST
DESIGN
ELEMENTS
EQUIPMENT
FLOW REGULATORS
FLUID FLOW
FUEL ASSEMBLIES
FUEL CYCLE
FUEL ELEMENTS
FUEL RODS
HYDROGEN
INTAKE STRUCTURES
MECHANICAL STRUCTURES
METALS
MODERATORS
NONMETALS
OPERATION
POWER REACTORS
QUANTITY RATIO
REACTIVITY
REACTOR COMPONENTS
REACTORS
URANIUM
VALVES