FAIL-SAFE CONTROL ROD DRIVE SYSTEM FOR NUCLEAR REACTOR

摘要

A control rod drive system (CRDS) for use in a nuclear reactor. In one embodiment, the system generally includes a drive rod mechanically coupled to a control rod drive mechanism (CRDM) operable to linearly raise and lower the drive rod along a vertical axis, a rod cluster control assembly (RCCA) comprising a plurality of control rods insertable into a nuclear fuel core, and a drive rod extension (DRE) releasably coupled at opposing ends to the drive rod and RCCA. The CRDM includes an electromagnet which operates to couple the CRDM to DRE. In the event of a power loss or SCRAM, the CRDM may be configured to remotely uncouple the RCCA from the DRE without releasing or dropping the drive rod which remains engaged with, the CRDM and in position.

主权项

1. A control rod drive system for a nuclear reactor vessel, the system comprising:
a vertically oriented drive rod mechanically coupled to a control rod drive mechanism operable to raise and lower the drive rod through a plurality of axial positions; a rod cluster control assembly comprising a plurality of control rods configured for removable insertion into a nuclear fuel core; a drive rod extension extending axially between the rod cluster control assembly and the drive rod, the drive rod extension having a bottom end releasably coupled to the rod cluster control assembly; and a drive rod extension grapple assembly connected to the drive rod, the grapple assembly releasably coupled to a top end of the drive rod extension; wherein raising and lowering the drive rod raises and lowers the rod cluster control assembly.