CN112216410A

CN112216410A - Multifunctional safety rod for space nuclear reactor

Info

Publication number: CN112216410A
Application number: CN202010856790.9A
Authority: CN
Inventors: 安伟健; 胡古; 郭键; 葛攀和; 葛思淼; 刘天才; 赵守智; 高剑; 李来冬; 丁明哲
Original assignee: China Institute of Atomic of Energy
Current assignee: China Institute of Atomic of Energy
Priority date: 2020-08-24
Filing date: 2020-08-24
Publication date: 2021-01-12

Abstract

The invention belongs to the technical field of nuclear reactors, and particularly relates to a multifunctional safety rod for a spatial nuclear reactor, which comprises a safety rod (1) and a follower (2) which are connected in series, wherein the safety rod (1) is used for ensuring the safety of the spatial nuclear reactor under the working condition of a launching drop accident, and the follower (2) is used for moderating neutrons of a reactor core of the spatial nuclear reactor, so that the reactivity of the spatial nuclear reactor is increased, and meanwhile, the axial power non-uniformity factor of the reactor core of the spatial nuclear reactor is reduced. The invention can provide extra reactivity for the space nuclear reactor, can help reduce the fuel loading, the weight and the volume of the reactor, reduce the cost and help reduce the axial power uneven factor of the space nuclear reactor.

Description

Multifunctional safety rod for space nuclear reactor

Technical Field

The invention belongs to the technical field of nuclear reactors, and particularly relates to a multifunctional safety rod for a space nuclear reactor.

Background

The reactor cores of many space nuclear reactors are provided with safety rods in the design scheme, and the safety rods are used for ensuring the safety of the reactor under the working condition of launching and falling accidents, so that the reactor can still maintain a subcritical state even if entering water, wet sand and the like.

When the space nuclear reactor is launched, the safety rods are positioned in the reactor core, and when the space nuclear reactor is successfully launched and is ready to be started, the safety rods are drawn out of the reactor core, and the reactor starts to run under the control of the control mechanism. In the existing scheme, the safety rod mainly has the following two operation modes:

(1) a first mode of operation is shown in figures 4 and 5. When the safety rod is successfully launched, the safety rod is drawn out of the reactor core and enters the shielding body to become a part of the shielding body material, so that a partial shielding function can be provided. This mode of operation is used for the safety rods of the US SP-100 reactor (cf. the document "culture of space nuclear reactor power systems").

(2) A second mode of operation is shown in figures 6 and 7. During firing, the safety rods are located in the core, and when the reactor is ready to start after successful firing, the safety rods are drawn forward out of the core and out of the reactor system into outer space. The reactor safety rod proposed in Promiers project of the United states adopts this operation mode (refer to "Prometheus project reactor module final report, for naval reactor information").

Disclosure of Invention

Based on the knowledge of the defects of the prior art, the invention aims to provide a novel safety rod scheme, which has two novel functions on the basis of the prior scheme: 1. providing additional reactivity to the space nuclear reactor can help reduce fuel loading, reactor weight and volume, and cost; 2. helping to reduce the axial power non-uniformity factor of a spatial nuclear reactor.

In order to achieve the above object, the present invention adopts a technical solution of a multifunctional safety rod for a spatial nuclear reactor, including a safety rod and a follower connected in series, wherein the safety rod is used for ensuring safety of the spatial nuclear reactor under a launch-drop accident condition, and the follower is used for moderating neutrons in a core of the spatial nuclear reactor, so as to increase reactivity of the spatial nuclear reactor and reduce an axial power nonuniformity factor of the core of the spatial nuclear reactor.

Furthermore, the safety rod and the follower are both cylindrical and have the same diameter, and the safety rod and the follower are coaxial.

Further, a cavity is arranged inside the follower body.

Further, the cavity is located in the middle of the follower.

Further, the safety rod is made of boron carbide.

Furthermore, the material of the follower is beryllium or beryllium oxide.

The invention has the beneficial effects that:

1. at the start-up of the space nuclear reactor, the safety rods 1 are drawn back out of the active region 7 of the reactor (i.e. the core) and into the shield inner bore 5 of the shield 4 as part of the shield 4 material, thus reducing the initial weight of the shield 4.

2. When safety rod 1 is put forward reactor active region 7, follow body 2 and get into reactor active region 7, can play the effect that the neutron was moderated, for the reactor provides extra reactivity, can help reducing fuel loading, reduce reactor weight and volume, reduce cost.

3. The cavity 3 is arranged in the central area of the follower 2, so that after entering the reactor active area 7, the neutron moderation provided in the central area of the reactor active area 7 is smaller than that provided in the two end areas of the reactor active area 7, which can help to reduce the axial power non-uniformity factor of the core of the spatial nuclear reactor.

Drawings

FIG. 1 is a schematic view of a multifunction safety rod for a spatial nuclear reactor according to an embodiment of the present invention;

FIG. 2 is a schematic view of a spatial nuclear reactor provided with a multifunction safety rod for a spatial nuclear reactor according to an embodiment of the invention (the spatial nuclear reactor is in an inactive state, the safety rod 1 is located in the core);

FIG. 3 is a schematic view of a spatial nuclear reactor provided with a multifunction safety rod for a spatial nuclear reactor according to an embodiment of the present invention (the spatial nuclear reactor is in operation, the safety rod 1 is withdrawn from the core, and the follower 2 is located in the core);

FIG. 4 is a schematic representation of a first mode of operation of a safety rod of the background of the invention (the spatial nuclear reactor is not in operation and the safety rod 1 is in the core);

FIG. 5 is a schematic view of a first mode of operation of the safety rods of the background of the invention (the spatial nuclear reactor is in operation, with the safety rods 1 withdrawn from the core);

FIG. 6 is a schematic representation of a second mode of operation of the safety rod of the background of the invention (the spatial nuclear reactor is not in operation and the safety rod 1 is in the core);

FIG. 7 is a schematic view of a second mode of operation of the safety rods of the background of the invention (the spatial nuclear reactor is in operation, with the safety rods 1 withdrawn from the core);

in the figure: 1-safety rod, 2-follower, 3-cavity, 4-shield, 5-shield internal pore channel, 6-axial reflecting layer, 7-reactor active region, 8-radial reflecting layer and 9-in-core safety rod pore channel.

Detailed Description

The invention is further described below with reference to the figures and examples.

As shown in fig. 1, the multifunctional safety rod for a spatial nuclear reactor provided by the invention comprises a safety rod 1 and a follower 2, wherein the safety rod 1 and the follower 2 are connected in series, the safety rod 1 is used for ensuring the safety of the spatial nuclear reactor under the condition of a launching drop accident, and the follower 2 is used for moderating neutrons of a core of the spatial nuclear reactor, so that the reactivity of the spatial nuclear reactor is increased, and meanwhile, the axial power non-uniform factor of the core of the spatial nuclear reactor is reduced.

The safety rod 1 and the follower 2 are both cylindrical and have the same diameter, and are coaxial.

The inside cavity 3 that is equipped with of follow-up body 2, cavity 3 are located the middle part of follow-up body 2.

The safety rod 1 is made of boron carbide, and the follower 2 is made of beryllium or beryllium oxide.

Finally, specific applications of the invention are used as further description:

as shown in fig. 2 and 3, when the spatial nuclear reactor is in the emission phase, the safety rod 1 is located in the reactor active area 7 of the reactor core, so that the reactor can be ensured to be in a subcritical safety state under various accident conditions; when the space nuclear reactor is ready to be started after a successful launch, the safety rods 1 are withdrawn from the core region 7 and enter the shield interior bore 5 of the shield 4, becoming part of the shield 4 material and providing part of the shielding function. Meanwhile, the follower 2 enters the reactor active region 7, provides a certain neutron moderation effect for the reactor core, and introduces a certain reactivity. The cavity 3 is provided in the central region of the follower 2, so that the moderation provided in the central region of the reactor active zone 7 is less than in the regions at the two ends of the reactor active zone 7, which helps to reduce the axial power non-uniformity factor of the core of the spatial nuclear reactor.

The device according to the present invention is not limited to the embodiments described in the specific embodiments, and those skilled in the art can derive other embodiments according to the technical solutions of the present invention, and also belong to the technical innovation scope of the present invention.

Claims

1. A multifunction safety bar for a spatial nuclear reactor, comprising: including safety stick (1) and follower (2) that are in series connection together, safety stick (1) is used for guaranteeing the security of space nuclear reactor under the accident operating mode is dropped in the transmission, follower (2) are used for the neutron of the reactor core of space nuclear reactor is slowed down, increases the reactivity of space nuclear reactor reduces simultaneously the axial power inhomogeneous factor of the reactor core of space nuclear reactor.

2. The multifunctional safety rod for a spatial nuclear reactor as set forth in claim 1, wherein: the safety rod (1) and the follower (2) are both cylindrical and have the same diameter, and the safety rod and the follower are coaxial.

3. The multifunctional safety rod for a spatial nuclear reactor as set forth in claim 2, wherein: the following body (2) is internally provided with a cavity (3).

4. A multifunction safety rod for a spatial nuclear reactor as set forth in claim 3, further comprising: the cavity (3) is positioned in the middle of the follower (2).

5. The multifunctional safety rod for a spatial nuclear reactor as set forth in claim 1, wherein: the safety rod (1) is made of boron carbide.

6. The multifunctional safety rod for a spatial nuclear reactor as set forth in claim 1, wherein: the follow-up body (2) is made of beryllium or beryllium oxide.