Control rod position indication system for a nuclear reactor

Patent metadata

Field	Value
Publication number	US-11967437-B2
Application number	US-201917609611-A
Country	US
Kind code	B2
Filing date	Jun 19, 2019
Priority date	Jun 19, 2019
Publication date	Apr 23, 2024
Grant date	Apr 23, 2024

Abstract

A control rod position indication system is for a nuclear reactor with a reactor core and at least one control rod which is movable along a linear path of movement for controlling reactivity of the core. The system includes a permanent magnet mounted on the control rod or a corresponding drive rod, and a number of reed switches arranged around the path of movement in order to be switched by a magnetic field generated by the permanent magnet when passing by. The permanent magnet has a north-south axis whose orientation is constant during movement, and the respective reed switch has a number of reed contacts which are aligned along a longitudinal axis. The longitudinal axis of at least one reed switch is inclined relative to the north-south axis of the permanent magnet, and the angle of inclination has an absolute value within a range from 15 to 65 degrees.

First claim

What is claimed is:

1. A nuclear reactor comprising:
a reactor core;
at least one control rod which is movable along a linear path of movement for controlling the reactivity of the reactor core; and
a control rod position indication system comprising:
a permanent magnet mounted on the control rod or a corresponding drive rod; and
a number of reed switches arranged around the path of movement in order to be switched by a magnetic field generated by the permanent magnet when passing by,
the permanent magnet having a north-south axis whose orientation is constant during movement, and the respective reed switch having a number of reed contacts which are aligned along a longitudinal axis,
the longitudinal axis of at least one of the reed switches being inclined relative to the north-south axis of the permanent magnet, and the angle of inclination having an absolute value within a range from 15 to 65 degrees.

2. The nuclear reactor according to claim 1 , wherein the nuclear reactor is a pressurized water reactor.

3. The nuclear reactor according to claim 1 , wherein the absolute value of the angle of inclination is within a range from 30 to 40 degrees.

4. The nuclear reactor according to claim 1 , wherein the north-south axis of the permanent magnet is arranged in parallel to the path of movement.

5. The nuclear reactor according to claim 1 , wherein all the reed switches are inclined in a same manner.

6. The nuclear reactor according to claim 1 , wherein a plurality of the reed switches are arranged at a same axial position of the control rod or the drive rod to provide redundant information.

Assignees

• Framatome Gmbh

Inventors

• Roux Jean-Luc
• Köhler-Soto Patrick
• Schön-Wälder Stefan

Classifications

• G21C17/12 Primary

  Sensitive element forming part of control element · CPC title

• G01D5/2515

  with magnetically controlled switches, e.g. by movement of a magnet · CPC title

• G21C17/10 Primary

  Structural combination of fuel element, control rod, reactor core, or moderator structure with sensitive instruments, e.g. for measuring radioactivity, strain · CPC title

• Y02E30/30

  Nuclear fission reactors · CPC title