High-thermal-conductivity uranium dioxide single crystal composite fuel pellet and preparation method thereof

A composite fuel, uranium dioxide technology, applied in the field of nuclear power, can solve the problems of containment and unfavorable fission products, and achieve the effect of offsetting self-blocking and loss, shortening the cycle of research and development, and reducing risks.

Active Publication Date: 2020-11-13
SHANGHAI NUCLEAR ENG RES & DESIGN INST CO LTD
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

Simultaneous polycrystalline UO 2 A large number of grain boundaries in the pellets are also easy to form diffusion channels for fission products, which is not conducive to containing radioactive fission products inside the fuel pellets

Method used

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  • High-thermal-conductivity uranium dioxide single crystal composite fuel pellet and preparation method thereof
  • High-thermal-conductivity uranium dioxide single crystal composite fuel pellet and preparation method thereof
  • High-thermal-conductivity uranium dioxide single crystal composite fuel pellet and preparation method thereof

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Experimental program
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Effect test

Embodiment 1

[0023] figure 2 As shown, a high thermal conductivity uranium dioxide single crystal composite fuel pellet, the pellet is UO 2 The single crystal is a fuel particle, and the fuel particle uses SiC powder as a connection medium, and the outer surface of the fuel particle and the connection medium is wrapped with a fuel-free area.

[0024] image 3 shown, using UO 2 The single crystal is used as the dispersed phase, and the second phase of SiC is used as the connecting medium. Using the mechanical method, the UO 2 Mix single crystal and SiC powder evenly, add Al 2 o 3 Powder, etc. are used as sintering aids, and pressed into green bodies. Then, the green body was sintered at 1800°C by a pressureless sintering process, and a columnar composite fuel pellet with a dish-shaped depression at the end and chamfered edges was prepared by machining.

[0025] Figure 4 for the adoption of UO 2 The fuel element of single crystal / SiC composite fuel pellets, the cladding material i...

Embodiment 2

[0027] The difference between this embodiment and the first embodiment is that Zr metal powder is used as the connection medium, and no sintering aid is added. The sintering temperature is 1600°C.

[0028] The above-mentioned high thermal conductivity composite fuel pellets of the present invention are exemplified as follows:

[0029] 1. In composite fuel pellets, UO 2 Single crystal accounts for 80% of the total volume, and SiC accounts for 20% of the total volume. The thermal conductivity of the composite fuel pellet at 1200 °C is about 5.2 W m -1 ·K -1 .

[0030] 2. In composite fuel pellets, UO 2 Single crystal accounts for 50% of the total volume, and SiC accounts for 50% of the total volume. The thermal conductivity of the composite fuel pellet at 1200 °C is about 10.9 W m -1 ·K -1 .

[0031] 3. Among composite fuel pellets, UO 2 Single crystal accounts for 80% of the total volume, and Zr accounts for 20% of the total volume. The thermal conductivity of the co...

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Abstract

The invention discloses a high-thermal-conductivity uranium dioxide single crystal composite fuel pellet and a preparation method thereof. The pellet takes UO2 single crystals as fuel particles, the fuel particles take SiC, Zr and other high-thermal-conductivity metal or ceramic material powder as a connecting medium, and the fuel particles and the connecting medium are wrapped with fuel-free areas reserved on the outer surfaces. The novel UO2 single crystal composite fuel researched and developed by the invention effectively counteracts self-obstruction and loss caused by the heat conductiondirectivity of UO2. According to the scheme, the thermal conductivity of the material is improved under the condition that the chemical activity of the fuel pellet is reduced, and the binary compositepellet fuel is excellent.

Description

technical field [0001] The invention belongs to the technical field of nuclear power, in particular to a nuclear fuel which can be used as a light water reactor and has accident resistance. Background technique [0002] Light water reactor is currently the main construction reactor type of nuclear power plants in various countries, and this type of nuclear power plants uses rod-shaped nuclear fuel elements. Rod-shaped nuclear fuel elements consist of short cylindrical UO 2 Composed of fuel pellets, zirconium alloy cladding, end plugs, compression springs in the air storage chamber, etc., there is a certain gap between the fuel pellets and the cladding, and the fuel element is filled with inert gas, such as figure 1 shown. [0003] UO 2 With the advantages of high melting point, high chemical and radiation stability, it has become the most widely used light water reactor nuclear fuel. However, since UO 2 Relying on phonon heat conduction, this feature causes the grain bo...

Claims

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Application Information

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Patent Type & Authority Applications(China)
IPC IPC(8): G21C3/58G21C3/60G21C21/16
CPCG21C3/60G21C3/58G21C21/16Y02E30/30
Inventor 刘婵云毛兰方陆辉韦享雨王喆卢俊强李聪
Owner SHANGHAI NUCLEAR ENG RES & DESIGN INST CO LTD
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