CN211319730U

CN211319730U - Fuel rod with weak PCI effect for liquid lead bismuth cooling ADS reactor

Info

Publication number: CN211319730U
Application number: CN201922328404.4U
Authority: CN
Inventors: 陈忠; 吕中良; 赵子甲; 袁宝新; 潘冬梅; 马燕云
Original assignee: Southwest University of Science and Technology
Current assignee: Southwest University of Science and Technology
Priority date: 2019-12-23
Filing date: 2019-12-23
Publication date: 2020-08-21
Anticipated expiration: 2029-12-23

Abstract

The utility model discloses a weak PCI effect fuel rod for liquid lead bismuth cooling ADS reactor, which comprises a columnar shell, a cladding area symmetrically cladded at two ends of the columnar shell, and a plurality of fuel pellets axially arranged in the columnar shell; the fuel pellet comprises a fuel rod main body and a cylindrical gap, and a gap is reserved between the outer edge of the fuel rod main body and the cylindrical shell; the cylindrical gap and the gap together form a gas containing part. The utility model realizes the easy assembly effect of the fuel pellet by arranging the penetrating cylindrical gap along the central axis of the fuel rod main body, can be remotely mechanically operated and is beneficial to preventing personnel from receiving high radioactive irradiation; after the assembly is accomplished, cylindricality space, clearance form gaseous accommodation portion jointly and can effectively contain produced fission gas and fission product among the fuel pellet release energy process, reduce the PCI effect, prevent that the column casing from breaking, are favorable to the extension the utility model discloses a life just is favorable to safety.

Description

Fuel rod with weak PCI effect for liquid lead bismuth cooling ADS reactor

Technical Field

The utility model relates to a nuclear reactor technical field specifically is a liquid lead bismuth cooling ADS fuel rod for reactor of weak PCI effect.

Background

The high-level nuclear waste is less than 3% of the total amount of the spent fuel of the nuclear reactor, but concentrates the radioactivity of more than 99% of the spent fuel, and has great danger to the life on the earth. Therefore, the treatment of high level nuclear waste is an important point in radioactive waste management and is also a worldwide problem. In order to solve the problem of nuclear waste, an advanced closed fuel cycle, namely a separation-transmutation (PT) strategy is internationally provided. An Accelerator Driven Sub-critical System (ADS) is an ideal device for transmuting nuclear waste and producing energy, has good resource and environmental benefits, and has been developed for medium and long term route planning and early basic research in the united states, european union, japan, russia, korea and our country. Due to the advantages of liquid lead bismuth LBE as a coolant in the aspects of neutronics, thermal engineering, physicochemical properties, low irradiation damage and the like, LBE is selected as the coolant in the scheme design of the international ADS transmutation reactor.

The core material of the nuclear reactor needs to stably work for a long time under extreme conditions of high temperature, high humidity, high stress, high radioactivity, high irradiation flux, strong corrosive environment and the like, so the safety is always the core target of the nuclear reactor. For nuclear reactors, the fuel elements are the core components of the reactor. As burn-up progresses, some potential danger threatens the integrity of the fuel element, thereby reducing its operating life. The main factors that disrupt the integrity of the fuel rod are Pellet-Cladding Interaction (PCI), a generic term for mechanical interactions that may occur between pellets and Cladding and chemical interactions of fission products within the fuel rod with the Cladding during irradiation of the fuel rod. The PCI effect can lead to corrosion cracking of the fuel rod cladding and even fuel failure. The traditional way for solving the influence factor is to line the inner wall of the cladding tube with a pure zirconium (Zr) layer, and the pure zirconium (Zr) layer and the pure zirconium layer are combined through a metallurgical technology, so that the aim of relieving the stress generated by the inner wall of the cladding tube in the PCI effect is fulfilled.

For high-burnup fuel assemblies, one of the essential features thereof, namely, the amount of fission gas emissions, is increased. Fission gas accumulates into bubbles to cause fuel swelling, and the size of the bubbles is an important factor influencing irradiation swelling and is also a key factor determining the PCI effect. Therefore, the fuel assembly is required to contain sufficient gas before the end of its useful life. Currently fuel pellets mainly use a butterfly design to control the PCI effect.

The ADS of transmutation nuclear waste has as fuel core the highly radioactive actinides ma (minor activities). Therefore, protection from the radioactivity must be considered during the fuel manufacturing process. With high-level nuclear fuels, the process of fitting into a fuel clad is difficult with current butterfly fuel pellets.

The patent CN 201310011086.3 discloses a fuel assembly for a liquid heavy metal cooled reactor and a fixing method thereof, and particularly develops the structure and fixing method design of the fuel assembly for the liquid heavy metal cooled reactor, and overcomes the buoyancy of a liquid heavy metal coolant by adopting a method of a circular sleeve and a pin positioning frame. In patent CN201310195644.3, a liquid heavy metal cooled reactor fuel assembly is disclosed, and the structural design is specifically developed for a fuel system and a counterweight system for fixing the fuel assembly. A lead alloy coolant zero power reactor fuel assembly is disclosed in patent CN 201510067562.2, specifically with respect to the structural design of the assembly housing, solid lead alloy sheets and fuel element rods. However, these published patents do not design fuel assemblies with highly radioactive minor actinides MA as fuel core, and the related fuel assemblies of international ADS reactors structurally do not take into account the problems of assembly of high-level fuel assemblies and weakening of PCI effect.

Therefore, there is a need for a fuel rod for a liquid lead-bismuth cooled reactor, which is easy to assemble and has high burnup and weak PCI effect.

SUMMERY OF THE UTILITY MODEL

The utility model discloses the technical problem that will solve is: provides a fuel rod for a liquid lead bismuth cooling reactor, which is easy to assemble and has high fuel consumption and weak PCI effect.

In order to solve the technical problem, the utility model discloses a realize through following technical scheme: a fuel rod with weak PCI effect for a liquid lead bismuth cooling ADS reactor comprises a cylindrical shell with a hollow structure inside, cladding areas symmetrically and hermetically coated at two ends of the cylindrical shell, and a plurality of fuel pellets axially arranged in the cylindrical shell;

the fuel pellet comprises a fuel rod main body and a cylindrical gap which is formed along the central axis of the fuel rod main body in a penetrating mode, and a gap is reserved between the outer edge of the fuel rod main body and the cylindrical shell;

the cylindrical voids and gaps together form a gas containment for fission gases and products produced during the release of energy by the fuel pellets.

Furthermore, the fuel pellet is of a cylindrical rod body structure, a Zr material is used as a matrix, and a high-radioactivity MA and Pu mixed metal fuel is used as a core fuel.

Further, the ratio of MA to Pu in the core fuel is 1:1, and the Zr, the MA and the Pu act together in an ADS reactor to generate fission and generate energy.

Further, a plurality of the fuel pellets are arranged in a grid within the cylindrical housing.

Further, the fuel pellets are arranged in parallel with the cylindrical shell.

Further, the outer diameter of the gap is matched with the inner diameter of the cylindrical shell.

Further, the radial section of the gap is annular.

Further, the cross section of the cylindrical gap in the radial direction is any one of a regular polygon, a circle and an ellipse.

Furthermore, the cylindrical shell is made of T91 steel material.

The utility model also provides a liquid lead bismuth cooling ADS reactor of weak PCI effect, including holding the pipe of pressurized fluid and as before the liquid lead bismuth cooling ADS reactor of weak PCI effect uses the fuel rod.

Compared with the prior art, the utility model discloses an useful part is:

the utility model provides a liquid lead bismuth of weak PCI effect cools off fuel rod for ADS reactor, through set up the cylindricality space that runs through along the center pin of fuel rod main part, realizes the easy assembly effect of fuel pellet, but remote mechanical operation is favorable to preventing personnel from receiving high radioactivity irradiation; after the assembly is accomplished, the clearance of reserving between cylindricality space, the fuel rod main part outer fringe and the column casing forms gaseous accommodation portion jointly, can effectively contain produced fission gas and fission product of fuel pellet release energy in-process, reduces the PCI effect, prevents that the column casing from breaking, is favorable to the extension the utility model discloses a life just is favorable to safety.

Drawings

In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings needed to be used in the description of the embodiments or the prior art will be briefly described below, it is obvious that the drawings in the following description are only some embodiments of the present invention, and for those skilled in the art, other drawings can be obtained according to the structures shown in the drawings without creative efforts.

The present invention will be further explained with reference to the accompanying drawings:

FIG. 1 is a schematic structural view of a fuel rod for a liquid lead bismuth cooled ADS reactor with weak PCI effect according to the present invention;

FIG. 2 is a top view of FIG. 1;

11. a fuel rod body; 12. a cylindrical void; 13. a gap; 2. a cylindrical housing; 3. a shell-coating area.

Detailed Description

The technical solutions in the embodiments of the present invention will be described clearly and completely with reference to the accompanying drawings in the embodiments of the present invention, and it is obvious that the described embodiments are only some embodiments of the present invention, not all embodiments. Based on the embodiments in the present invention, all other embodiments obtained by a person skilled in the art without creative efforts belong to the protection scope of the present invention.

It should be noted that all the directional indicators (such as upper, lower, left, right, front and rear … …) in the embodiment of the present invention are only used to explain the relative position relationship between the components, the motion situation, etc. in a specific posture (as shown in the drawings), and if the specific posture is changed, the directional indicator is changed accordingly.

In addition, descriptions in the present application as to "first", "second", and the like are for descriptive purposes only and are not to be construed as indicating or implying relative importance or implicit to the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include at least one such feature. In the description of the present invention, "a plurality" means at least two, e.g., two, three, etc., unless specifically limited otherwise.

In the present application, unless expressly stated or limited otherwise, the terms "connected" and "fixed" are to be construed broadly, e.g., "fixed" may be fixedly connected or detachably connected, or integrally formed; the connection can be mechanical connection, electrical connection, physical connection or wireless communication connection; they may be directly connected or indirectly connected through intervening media, or they may be connected internally or in any other suitable relationship, unless expressly stated otherwise. The specific meaning of the above terms in the present invention can be understood according to specific situations by those skilled in the art.

In addition, the technical solutions between the embodiments of the present invention can be combined with each other, but it is necessary to be able to be realized by a person having ordinary skill in the art as a basis, and when the technical solutions are contradictory or cannot be realized, the combination of such technical solutions should be considered to be absent, and is not within the protection scope of the present invention.

Example one

The fuel rod for the liquid lead bismuth cooled ADS reactor with the weak PCI effect as shown in fig. 1-2 comprises a cylindrical shell 2 with a hollow structure inside, cladding areas 3 symmetrically and hermetically coated at two ends of the cylindrical shell 2, and a plurality of fuel pellets arranged in a grid manner in the cylindrical shell 2 along the axial direction, wherein in the embodiment, the fuel pellets are in a cylindrical rod structure, and a Zr material is used as a matrix, and a high-radioactivity MA and Pu mixed metal fuel is used as a core fuel.

The fuel pellet includes fuel rod main part 11 and follows the 11 center pins of fuel rod main part run through the cylindricality space 12 of seting up, the outer fringe of fuel rod main part 11 with reserve between the cylindrical shell 2 and have clearance 13, clearance 13 is the ring form along radial cross-section, and its external diameter cooperatees with the internal diameter of cylindrical shell 2, in this embodiment, cylindricality space 12 is the cuboid space, and along radial cross-section for the square, and the length of side of this square is 0.15cm, can realize through this design the easy assembly effect of fuel pellet realizes the easy preparation assembly work of modern industry technique through this cuboid space, further realizes the assembly operation of long-range mechanical high-level fuel pellet.

Cylindricality space 12 forms jointly with clearance 13 the gaseous container of produced fission gas and fission product among the fuel pellet release energy process can effectively contain produced fission gas and fission product among the fuel pellet release energy process when irradiation in the reactor, reduces the PCI effect, prevents that column casing 2 from breaking, is favorable to the extension the life of fuel rod and to safe favourable.

Preferably, the ratio of MA to Pu in the core fuel is 1:1, and the Zr, the MA and the Pu act together in an ADS reactor to generate fission and energy.

Preferably, the cylindrical shell 2 is made of T91 steel material, and the mass density of the T91 steel material is 7.8g/cm³The fission gas and fission product can be prevented from escaping, thereby avoidingThe fuel is corroded by the liquid lead-bismuth coolant and effectively leads out heat energy.

Preferably, the axial length of the fuel rod main body 11 of each fuel pellet is 1cm, the outer diameter of the fuel rod main body is 0.576cm, and the axial length of a cuboid gap inside the fuel rod main body is equal to the length of the fuel rod main body 11, so that the easy assembly effect of the high-level fuel pellets and the effect of effectively containing fission gas and fission products generated in the process of releasing energy by the fuel pellets in the irradiation process of a reactor are realized, and the PCI effect is reduced.

The utility model discloses a concrete use is: a penetrating cylindrical gap is formed along the central shaft of each fuel rod main body, so that the easy assembly effect of the fuel pellets is realized, and the remote mechanical operation can be realized; a plurality of fuel pellets are arranged in the cavity of the cylindrical shell 2, and after the fuel pellets are assembled, the head end and the tail end of the cylindrical shell 2 are sealed through a shell wrapping area 3 respectively; in the process of releasing energy by the fuel pellets, the cylindrical gap, the reserved gap between the outer edge of the fuel rod main body and the cylindrical shell form a gas containing part together, so that fission gas and fission products generated in the process of releasing energy by the fuel pellets can be effectively contained, the PCI effect is reduced, and the cylindrical shell is prevented from cracking.

P refers to the pressure of the ideal gas, V is the volume of the ideal gas, n represents the amount of gas species, T represents the thermodynamic temperature of the ideal gas, and R is the ideal gas constant, according to the ideal gas state equation PV-nRT. The stress generated by the fission gas on the inner wall of the cylindrical shell 2 can be regarded as the pressure P of the ideal gas, which is inversely proportional to V and directly proportional to n; in this embodiment, consider that the burnup degree of depth of current reactor and suitable extrapolation to 10%, the cuboid space can hold the fission gas of at least 10% burnup degree of depth at radial square area in fuel rod main part 11 from this, compares with the space that the previous butterfly design reserved and hold fission gas, the utility model discloses the space that holds fission gas accounts for than being 47%, and the effect is more excellent.

Example two

The fuel rod for the liquid lead bismuth cooling ADS reactor with the weak PCI effect as shown in the attached figures 1-2 comprises a cylindrical shell 2 with a hollow structure inside, cladding areas 3 symmetrically and hermetically coated at two ends of the cylindrical shell 2, and a plurality of fuel pellets axially arranged in the cylindrical shell 2;

the fuel pellet comprises a fuel rod main body 11 and a cylindrical gap 12 which is formed along the central axis of the fuel rod main body 11 in a penetrating mode, and a gap 13 is reserved between the outer edge of the fuel rod main body 11 and the cylindrical shell 2;

the cylindrical void 12 and the gap 13 together form a gas containment for fission gases and products produced during the energy release of the fuel pellets.

The difference from the first embodiment is that, in the present embodiment, the cylindrical void 12 is a cylindrical void and has a circular or elliptical cross section in the radial direction; in other embodiments of the present invention, the cylindrical gap 12 is a prism gap, and the radial cross section is a regular polygon, and the using process and the working principle are the same as those of the first embodiment.

EXAMPLE III

On the basis of embodiment one or embodiment two, the utility model provides a liquid lead bismuth cooling ADS reactor of weak PCI effect still, including the pipe that holds the pressurized fluid and as embodiment one or embodiment two the liquid lead bismuth cooling ADS reactor of weak PCI effect uses the fuel rod.

The above only be the preferred embodiment of the utility model discloses a not consequently restriction the utility model discloses a patent range, all are in the utility model discloses a conceive, utilize the equivalent structure transform of what the content was done in the description and the attached drawing, or direct/indirect application all is included in other relevant technical field the utility model discloses a patent protection within range.

Claims

1. A liquid lead bismuth of weak PCI effect cools off fuel rod for ADS reactor which characterized in that: the fuel pellet sealing device comprises a cylindrical shell (2) with a hollow structure inside, shell areas (3) symmetrically and hermetically coated at two ends of the cylindrical shell (2), and a plurality of fuel pellets axially arranged in the cylindrical shell (2);

the fuel pellet comprises a fuel rod main body (11) and a cylindrical gap (12) which is formed along the central shaft of the fuel rod main body (11) in a penetrating mode, and a gap (13) is reserved between the outer edge of the fuel rod main body (11) and the cylindrical shell (2);

the cylindrical interspace (12) and the gap (13) together form a gas containment for fission gases and products produced during the release of energy by the fuel pellets.

2. The fuel rod for the weak PCI effect liquid lead bismuth cooling ADS reactor of claim 1, wherein: the fuel pellet is in a cylindrical rod body structure, a Zr material is used as a matrix, and MA and Pu mixed metal fuel is used as core fuel.

3. The fuel rod for the weak PCI effect liquid lead bismuth cooling ADS reactor of claim 2, wherein: the ratio of MA to Pu in the core fuel is 1:1, and Zr, MA and Pu act together in an ADS reactor to generate fission and generate energy.

4. The fuel rod for the weak PCI effect liquid lead bismuth cooling ADS reactor of claim 2, wherein: a plurality of said fuel pellets are arranged in a grid within said cylindrical housing (2).

5. The fuel rod for the liquid lead bismuth-cooled ADS reactor with the weak PCI effect of claim 4, wherein: the fuel pellets are arranged parallel to the cylindrical housing (2).

6. The fuel rod for the liquid lead bismuth-cooled ADS reactor with the weak PCI effect of claim 5, wherein: the outer diameter of the gap (13) is matched with the inner diameter of the cylindrical shell (2).

7. The fuel rod for the liquid lead bismuth-cooled ADS reactor with the weak PCI effect of claim 6, wherein: the gap (13) is annular in cross section along the radial direction.

8. The fuel rod for the weak PCI effect liquid lead bismuth cooling ADS reactor of claim 1, wherein: the section of the cylindrical gap (12) in the radial direction is any one of a regular polygon, a circle and an ellipse.

9. The fuel rod for the weak PCI effect liquid lead bismuth cooling ADS reactor of any one of claims 1-8, wherein: the cylindrical shell (2) is made of T91 steel material.

10. A liquid lead bismuth cooling ADS reactor of weak PCI effect which characterized in that: fuel rod for a liquid lead bismuth cooled ADS reactor comprising a tube containing a pressurized fluid and the weak PCI effect according to any of claims 1-9.