Control rod damping system
AssigneeNuScale Power, LLC
InventorRoss Douglas Snuggerud
Life of this patent
Estimating the term…
Abstract
A damping area or “dash pot” on the upper ends of control rods absorb energy from dropped control rod assemblies without narrowing the diameter of guide tubes. As a result, coolant can freely flow through the guide tubes reducing boiling water issues. The dampening area reduces a separation distance between an outside surface of the control rod and an inside surface of the guide tubes decelerating the control rods when entering a top end of the guide tubes. In another example, the dampening area may be located on a drive shaft. The dampening area may have a larger diameter than an opening in a drive shaft support member that decelerates the drive shaft when dropped by a drive mechanism.
Claims6
A control rod for inserting into a guide tube of a nuclear reactor fuel assembly of a nuclear reactor module, comprising:
- a first section including an active material for inserting into the guide tube and controlling a fission rate in a nuclear reactor core, the first section having a first outside diameter;
- a second section configured to attach to a head assembly of the nuclear reactor module;
- a dampening section located between the first section and the second section, wherein the dampening section has a second outside diameter larger than the first outside diameter such that, the dampening section reduces a separation distance between an outside surface of the control rod and an inside surface of the guide tube to decelerate the control rod when entering a top end of the guide tube;
- and
- a spring positioned inside the dampening section between the first section and the second section.
Dependencies are inferred from the claim text.