Nuclear control rod position indication system

Patent metadata

Field	Value
Publication number	US-10020081-B2
Application number	US-201614996439-A
Country	US
Kind code	B2
Filing date	Jan 15, 2016
Priority date	Jan 15, 2016
Publication date	Jul 10, 2018
Grant date	Jul 10, 2018

Abstract

A pulsed sonar-based wireless rod position indication system that utilizes nuclear radiation and high temperature tolerant hardware. The pulsed sonar-based rod position indication system can precisely locate the rod position by measuring the time of flight of a transmitted signal and by using the phase and amplitude information of the same transmitted signal. Primary and secondary antenna probes located in the interior of the control rod drive rod travel housing and full hardware redundancy provide for improved accuracy. The time of flight, phase and amplitude raw signals are inputted to a wireless data transmitter capable of sending the raw signals to a receiver antenna located elsewhere inside a containment for further processing.

First claim

What is claimed is:

1. A nuclear reactor system having a reactor vessel that houses a nuclear core in which fissile reactions take place within a pressure boundary of the reactor vessel and a control rod system for controlling the fissile reactions, the control rod system comprising:
a control rod configured to move, within a sonically conductive coolant, into and out of the nuclear core, to control the fissile reactions;
a drive system for driving the control rod into and out of the core; and
a control rod position monitoring system comprising:
a sonar pulse generator configured to generate a series of sonar pulses;
an antenna fixedly positioned within the pressure boundary, above an upper limit of travel of the control rod and configured to receive the sonar pulses generated by the sonar pulse generator and transmit the sonar pulses to the upper portion of the control rod and receive a reflected sonar signal from the control rod and communicate the reflected sonar signal to a selected location a spaced distance from the antenna outside of the pressure boundary, wherein the control rod includes a control rod drive rod and a control rod drive rod housing surrounds an upper portion of a travel path of the control rod drive rod with the antenna supported within an interior of the control rod drive rod housing; and
a receiver positioned at the spaced distance from the antenna and configured to receive the reflected sonar signal and communicate the reflected sonar signal to a processing unit that is configured to analyze the reflected sonar signal to determine a control rod position.

2. The nuclear reactor system of claim 1 wherein the sonar pulse generator is supported outside of the coolant and transmits the series of sonar pulses wirelessly to the antenna.

3. The nuclear reactor system of claim 2 wherein the antenna transmits the reflected sonar signal wirelessly to the receiver.

4. The nuclear reactor system of claim 1 wherein the sonar signal is an ultrasonic signal.

5. The nuclear reactor system of claim 1 wherein the sonar pulse generator is a vacuum micro-electronic device.

6. The nuclear reactor system of claim 1 wherein the sonar pulse generator and the receiver are a vacuum micro-electronic device transceiver.

7. The nuclear reactor system of claim 1 wherein the control rod comprises a plurality of separately moveable control rods with each of the separately moveable control rods having a corresponding control rod position monitoring system, wherein the sonar pulses for each of the separately moveable control rod position monitoring systems has its own unique frequency.

8. The nuclear reactor system of claim 7 wherein the respective frequencies of the sonar pulses are different than any other frequencies of electromagnetic noise within the nuclear reactor system.

9. The nuclear reactor system of claim 1 wherein the control rod position monitoring system comprises redundant control rod position monitoring systems including two distinct sonar pulse generators that are independent of each other and two distinct receivers that are independent of each other.

10. The nuclear reactor system of claim 9 including two distinctly separate antennas.

11. The nuclear reactor system of claim 9 wherein the sonar pulses emitted from the two distinct sonar pulse generators are substantially emitted at the same frequency.

12. The nuclear reactor system of claim 9 wherein the sonar pulses emitted from the two distinct sonar pulse generators are emitted at separate distinct frequencies.

13. The nuclear reactor system of claim 1 wherein the antenna is a ceramic antenna.

14. The nuclear reactor system of claim 1 wherein power required to energize the sonar pulse generator and the receiver is supplied by a thermoelectric generator with a hot junction attached to the control rod drive rod housing and a cool junction located opposite the hot junction, away from the control rod drive rod housing.

15. The nuclear reactor system of claim 1 including a data transmitter that receives an original sonar pulse from the series of sonar pulses and a corresponding one of the reflected sonar signals, including amplitude and phase and sends the original sonar pulse and reflected sonar signal to a signal processing base station for computation.

16. The nuclear reactor system of claim 15 wherein the data transmitter is a wireless data transmitter.

17. The nuclear reactor system of claim 15 including a temperature sensor for monitoring a temperature within the control rod drive rod housing and operable to communicate that temperature to the data transmitter which is operable to transmit the temperature to the signal processing base station.

18. The nuclear reactor system of claim 17 wherein the temperature sensor includes a plurality of temperature sensors spaced along the control rod drive rod travel housing.

19. The nuclear reactor system of claim 17 wherein the signal processing base station is configured to determine the time of flight of the original sonar pulse and the reflected sonar signal and compensate the determination with the temperature.

Assignees

• Westinghouse Electric Co Llc

Inventors

• Carvajal Jorge V
• Heibel Michael D
• Arlia Nicola G
• Flammang Robert W
• Sumego David M
• James Michael A
• Walter Melissa M

Classifications

• G21C17/12 Primary

  Sensitive element forming part of control element · CPC title

• G01S15/88

  Sonar systems specially adapted for specific applications (seismic or acoustic prospecting or detecting G01V1/00) · CPC title

• Y02E30/30

  Nuclear fission reactors · CPC title

• G01S15/06

  Systems determining the position data of a target · CPC title

• G01S7/56

  Display arrangements {(short-range imaging G01S7/52053)} · CPC title