Nuclear reactor, methods for assembling and replacing thermocouple ducts, assembly for implementing these methods

Patent metadata

Field	Value
Publication number	US-11948699-B2
Application number	US-201716313868-A
Country	US
Kind code	B2
Filing date	Jun 26, 2017
Priority date	Jun 29, 2016
Publication date	Apr 2, 2024
Grant date	Apr 2, 2024

Abstract

A nuclear reactor includes a vessel (1), a support plate (8), arranged in the vessel (1) above the core (2); a plurality of separate dispensing ducts (21); and support members (33) provided to keep the thermocouple ducts (21) in position. Each support member (33) includes a foot (35) rigidly attached to the support plate (8), a head (37) to which the or each thermocouple duct (21) is attached, and a detachable connection (39) from the head (37) to the foot (35).

First claim

What is claimed is:

1. A nuclear reactor, comprising:
a vessel;
a plurality of nuclear fuel assemblies forming a reactor core arranged in the vessel;
a support plate arranged in the vessel above the reactor core;
a plurality of thermocouple ducts arranged in the vessel and passing through the support plate through dedicated orifices;
support members provided to keep the thermocouple ducts in position, each support member being rigidly attached to the support plate, each of the thermocouple ducts being attached to at least one of the support members, each thermocouple duct inwardly receiving and guiding a thermocouple;
each support member including a foot rigidly attached to the support plate, a head to which each thermocouple duct is attached, the head being detachably connected to the foot, the foot of each support member being arranged laterally offset with respect to the dedicated orifices; and
thermocouple columns extending above the support plate, a plurality of the thermocouple ducts being positioned in each thermocouple column and leaving the column through peripheral openings,
at least one of the thermocouple ducts being attached to at least two of the support members simultaneously, said at least two support members being distinct and being spaced apart from each other.

2. The reactor according to claim 1 , wherein the head is detachably connected to the foot by a screwed connection.

3. The reactor according to claim 1 , wherein the reactor comprises an upper core plate, the upper core plate being arranged between the support plate and the reactor core, the upper core plate and the support plate being maintained spaced apart from one another.

4. The reactor according to claim 1 , wherein the head comprises a core and a cap removably connected to the core, the core and the cap delimiting a plurality of housings for receiving the thermocouple ducts, the housing being delimited between the core and the cap.

5. The reactor according to claim 4 , wherein the core of the head is detachably connected to the foot.

6. The reactor according to claim 4 , wherein the housings are delimited by grooves hollowed in the core, the grooves being configured to guide the thermocouple ducts horizontally through the head.

7. The reactor according to claim 4 , wherein the housings are delimited by grooves hollowed in the core, the cap including at least one arm closing the groove.

8. The reactor according to claim 7 , wherein the reactor comprises branches, each thermocouple duct being arranged so as to join one of the branches, each branch being aligned with one of the dedicated orifices to form a passage of the thermocouple duct through the support plate, each support member being arranged away from the branches.

9. The reactor according to claim 7 , wherein the core has two vertical faces opposite one another, the grooves being arranged in at least one of the faces, the at least one arm having a surface pressed against the face in which the grooves are arranged.

10. The reactor according to claim 9 , wherein the face, in which the grooves are arranged, is a plane.

11. The reactor according to claim 9 , wherein the grooves are horizontal and parallel to one another.

12. A method for assembling thermocouple ducts in the nuclear reactor according to claim 1 , the method comprising:
assembling the foot of each of the support members on the support plate;
assembling end segments of the thermocouple ducts and the head of each of the support members to form a subassembly;
transferring the subassembly to a location above the support plate; and
attaching the head of each of the support members to a respective foot of each of the support members.

13. The method according to claim 12 , wherein the transferring of the subassembly includes:
attaching the subassembly to a rigid transport structure; and
moving the rigid transport structure with the subassembly to the location above the support plate.

14. The method according to claim 13 , wherein the rigid transport structure comprises a platform and members for attaching the head of each of the support members to the platform.

15. An assembly for implementing the assembly method according to claim 12 , the assembly comprising:
the support members provided to keep the thermocouple ducts in position, the foot of each of the support members provided with a first attachment for attaching the foot to the support plate, the head of each of the support members provided with a second attachment for attaching the thermocouple ducts to the head, the head being detachably connected to the foot; and
a transport structure, comprising a platform and members for attaching the head of each of the support members to the platform.

16. A method for replacing a first set of thermocouple ducts in the nuclear reactor according to claim 1 , wherein the plurality of thermocouple ducts are the first set thermocouple ducts, and wherein the support members are a first set of support members, the method comprising:
disassembling the head of each of the first set of support members from a respective foot of the first set of support members;
discharging the head of each of the first set of support members and end segments of the first set of thermocouple ducts;
assembling end segments of a second set of thermocouple ducts and a head of each of a second set of support members to form a subassembly;
transferring the subassembly to a location above the support plate; and
attaching the head of each of the second set of support members to a respective foot of the second set of support members.

17. A nuclear reactor, comprising:
a vessel;
a plurality of nuclear fuel assemblies forming a reactor core arranged in the vessel;
a support plate arranged in the vessel above the reactor core;
a plurality of thermocouple ducts arranged in the vessel and passing through the support plate through dedicated orifices;
support members provided to keep the thermocouple ducts in position, each support member being rigidly attached to the support plate, at least one of the thermocouple ducts being attached to each support member, each thermocouple duct inwardly receiving and guiding a thermocouple;
each support member including a foot rigidly attached to the support plate, a head to which the or each thermocouple duct is attached, the head being detachably connected to the foot, the foot of each support member being arranged laterally offset with respect to the dedicated orifices; and
thermocouple columns extending above the support plate, a plurality of the thermocouple ducts being positioned in each thermocouple column and leaving the column through peripheral openings.
wherein the head comprises a core and a cap removably connected to the core, the core and the cap delimiting a plurality of housings for receiving the thermocouple ducts, the housing being delimited between the core and the cap,
wherein the housings are delimited by grooves hollowed in the core, the cap including at least one arm closing the groove,
wherein the core has two vertical faces opposite one another, the grooves being arranged in at least one of the faces, the at least one arm having a surface pressed against the face in which the grooves are arranged.

18. The reactor according to claim 17 , wherein the face, in which the grooves are arranged, is a plane.

19. The reactor according to claim 17 , wherein the grooves are horizontal and parallel to one another.

Assignees

• Framatome Sa

Inventors

• Cahouet Laurent
• Magain Bruno
• Scalvini Alain

Classifications

• G21C17/112 Primary

  Measuring temperature · CPC title

• G21C5/02

  Details · CPC title

• G21C19/207

  Assembling, maintenance or repair of reactor components (G21C3/334 takes precedence) · CPC title

• G21C19/20

  Arrangements for introducing objects into the pressure vessel; Arrangements for handling objects within the pressure vessel; Arrangements for removing objects from the pressure vessel · CPC title

• Y02E30/30

  Nuclear fission reactors · CPC title