Passive visual fuel temperature indicator

Patent metadata

Field	Value
Publication number	US-10403408-B2
Application number	US-201213727048-A
Country	US
Kind code	B2
Filing date	Dec 26, 2012
Priority date	Dec 26, 2012
Publication date	Sep 3, 2019
Grant date	Sep 3, 2019

Abstract

A fuel bundle temperature sensing device may include an indicating rod made of a first material; an outer housing having an upper opening, the outer housing being made of a second material and surrounding at least a portion of the indicating rod; and a rod holder attached to an inner surface of the outer housing, the rod holder being made of a third material and being configured to support the indicating rod such that a top surface of the rod extends out of the upper opening of the outer housing, the third material having a lower melting point than the first and second materials.

First claim

What is claimed:

1. A nuclear reactor system comprising:
a fuel assembly including a fuel channel;
fuel rods inside the fuel channel; and
a temperature indicator inserted in between two or more of the fuel rods, the temperature indicator including,
an indicating rod made of a first material;
an outer housing having an upper opening, the outer housing being made of a second material and surrounding at least a portion of the indicating rod; and
a rod holder attached to an inner surface of the outer housing, the rod holder being made of a third material and being configured to support the indicating rod such that a top surface of the indicating rod extends out of the upper opening of the outer housing, the third material having a lower melting point than the first and second materials,

wherein,
the rod holder extends in a first direction from a first portion of the inner surface to a second portion of the inner surface opposite the first portion,
the indicating rod extends in a second direction from an upper surface of the rod holder out of the upper opening of the outer housing,
a length of the rod holder in the first direction is greater than a thickness of the rod holder in the second direction,
the indicating rod, the outer housing and the rod holder are each configured such that if the rod holder melts, the indicating rod will fall within the outer housing such that the top surface of the indicating rod is not visible above the upper opening of the outer housing, and
the rod holder is configured to melt at a temperature exceeding a threshold temperature in the fuel channel.

2. The nuclear reactor system of claim 1 , wherein the outer housing has a bottom surface that is spaced away from the upper opening and spaced away from a first position on the inner surface of the outer housing at which the rod holder is attached to the outer housing such that the first position is in between the upper opening and the bottom surface of the outer housing.

3. The nuclear reactor system of claim 2 , wherein a first distance between an uppermost surface of the indicating rod and the upper opening of the outer housing is less than a second distance between a lowermost surface of the indicating rod and the bottom surface of the outer housing.

4. The nuclear reactor system of claim 2 , wherein a region within the outer housing in between the first position and the bottom surface of the outer housing is filled with air.

5. The nuclear reactor system of claim 1 , wherein the third material is aluminum.

6. The nuclear reactor system of claim 1 , wherein the outer housing is cylindrical in shape and the rod holder is a circular disc attached to the inner surface of the outer housing.

7. The nuclear reactor system of claim 6 , wherein the circular disc is attached to the outer housing such that the circular disc spans an inner diameter of the outer housing.

8. The nuclear reactor system of claim 3 , wherein the indicating rod, the outer housing and the rod holder are each configured such that if the rod holder melts, the indicating rod will fall within the outer housing such that the lowermost surface of the indicating rod contacts and rests upon the bottom surface of the outer housing.

9. A nuclear reactor system comprising:
a fuel assembly including a fuel channel;
fuel rods inside the fuel channel; and
a temperature indicator inserted in between two or more of the fuel rods,
the temperature indicator including,
an indicating rod made of a first material,
an outer housing having an upper opening, the outer housing being made of a second material and surrounding at least a portion of the indicating rod, and
a rod holder attached to an inner surface of the outer housing, the rod holder being made of a third material and being configured to support the indicating rod such that a top surface of the indicating rod extends out of the upper opening of the outer housing, the third material having a lower melting point than the first and second materials,

wherein,
the rod holder extends in a first direction from a first portion of the inner surface to a second portion of the inner surface opposite the first portion,
the indicating rod extends in a second direction from an upper surface of the rod holder out of the upper opening of the outer housing,
a length of the rod holder in the first direction is greater than a thickness of the rod holder in the second direction,
the indicating rod, the outer housing and the rod holder are each configured such that if the rod holder melts, the indicating rod will fall within the outer housing such that the top surface of the indicating rod is not visible above the upper opening of the outer housing, and
the rod holder is configured to melt at a temperature exceeding a threshold temperature in the fuel channel.

10. The nuclear reactor system of claim 9 , wherein the outer housing has a bottom surface that is spaced away from the upper opening and spaced away from a first position on the inner surface of the outer housing at which the rod holder is attached to the outer housing such that the first position is in between the upper opening and the bottom surface of the outer housing.

11. The nuclear reactor system of claim 10 , wherein a first distance between an uppermost surface of the indicating rod and the upper opening of the outer housing is less than a second distance between a lowermost surface of the indicating rod and the bottom surface of the outer housing.

12. The nuclear reactor system of claim 10 , wherein a region within the outer housing in between the first position and the bottom surface of the outer housing is filled with air.

13. The nuclear reactor system of claim 9 , wherein the third material is aluminum.

14. The nuclear reactor system of claim 9 , wherein the outer housing is cylindrical in shape and the rod holder is a circular disc attached to the inner surface of the outer housing.

15. The nuclear reactor system of claim 14 , wherein the circular disc is attached to the outer housing such that the circular disc spans an inner diameter of the outer housing.

16. The nuclear reactor system of claim 11 , wherein the indicating rod, the outer housing and the rod holder are each configured such that if the rod holder melts, the indicating rod will fall within the outer housing such that the lowermost surface of the indicating rod contacts and rests upon the bottom surface of the outer housing.

17. The temperature indicator of claim 1 , wherein the indicating rod, the outer housing and the rod holder are each configured such that if the rod holder melts, the indicating rod will fall within the outer housing such that an uppermost surface of the indicating rod changes from being outside the outer housing and visible above the upper opening of the outer housing before the rod holder melts to being inside the outer housing and not being visible above the upper opening of the outer housing after the rod holder melts.

18. The nuclear reactor system of claim 9 , wherein the indicating rod, the outer housing and the rod holder are each configured such that if the rod holder melts, the indicating rod will fall within the outer housing such that an uppermost surface of the indicating rod changes from being outside the outer housing and visible above the upper opening of the outer housing before the rod holder melts to being inside the outer housing and not being visible above the upper opening of the outer housing after the rod holder melts.

19. A nuclear reactor system comprising:
a fuel asse

Assignees

• Umhoefer Elizabeth
• Pfeffer Scott
• Pfeffer Maria
• Ge Hitachi Nuclear Energy Americas Llc

Inventors

• Umhoefer Elizabeth
• Pfeffer Scott
• Pfeffer Maria

Classifications

• G21C3/326

  comprising fuel elements of different composition; comprising, in addition to the fuel elements, other pin-, rod-, or tube-shaped elements, e.g. control rods, grid support rods, fertile rods, poison rods or dummy rods · CPC title

• G21C17/112 Primary

  Measuring temperature · CPC title

• Y02E30/38

  Cross-Sectional Technologies · mapped topic

• Y02E30/30

  Nuclear fission reactors · CPC title