High-temperature steam corrosion resistant coating for zirconium alloy cladding tube

A technology for corroding coatings and cladding tubes, which is applied in the field of surface modification of reactor nuclear fuel zirconium alloy claddings, can solve the problems of plasticity reduction, failure, and high solid solubility of oxygen in cladding tubes, so as to improve wear resistance and durability. The effect of corrosion hydrogen absorption performance and strong high temperature steam corrosion resistance

Active Publication Date: 2021-01-01
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

However, the solid solubility of oxygen in zirconium alloy is high, and the cladding tube matrix under high temperature conditions can be obt

Method used

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  • High-temperature steam corrosion resistant coating for zirconium alloy cladding tube
  • High-temperature steam corrosion resistant coating for zirconium alloy cladding tube
  • High-temperature steam corrosion resistant coating for zirconium alloy cladding tube

Examples

Experimental program
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Effect test

Embodiment 1

[0033] A coating with pure Cr as the transition layer and pure Zr as the working layer is coated on the surface of the zirconium alloy sample. Its microstructure is as Figure 5 shown.

[0034] The characteristics of the embodiment of the present invention are: 1. Cr is used as the transition layer, which prevents oxygen from diffusing to the zirconium alloy substrate under high temperature conditions; 2. Pure Zr is used as the working layer, with a thickness of about 1-2 μm and high-temperature oxidation to ZrO 2 3. The Cr transition layer is only 2 μm, and the neutron economic loss of the fuel rod is equivalent to 1 / 2 of Comparative Example 2. After corroding in water vapor at 1000°C for 60 minutes, the weight gain is 500mg / dm 2 , the corrosion weight gain curve is as Figure 4 As shown, the corrosion weight gain was reduced by more than 85% compared to the uncoated zirconium alloy (Comparative Example 1).

Embodiment 2

[0036] A coating with pure Cr as the transition layer and zirconium + zirconia as the working layer is coated on the surface of the zirconium alloy sample.

[0037] The characteristics of the embodiment of the present invention are: 1. Using 1 μm of Cr as the transition layer prevents the oxygen element from diffusing to the zirconium alloy matrix under high temperature conditions, and the neutron economic loss of the fuel rod is only 1 / 4 of that of Comparative Example 2; 2. 1. Use 10μm pure Zr as the working layer, after high-temperature pre-oxidation treatment to generate zirconia with a thickness of about 6μm, after corroding in water vapor at 1000°C for 60min, the weight gain is less than 500mg / dm 2 , The corrosion weight gain was reduced by more than 85% compared with Comparative Example 1.

Embodiment 3

[0039] The surface of the zirconium alloy sample is coated with CrN as the transition layer and zirconium as the working layer.

[0040] The characteristics in the embodiment of the present invention are: 1. The CrN of 2 μm is used as the transition layer, which prevents the oxygen element from diffusing to the zirconium alloy matrix under high temperature conditions, and the neutron economic loss of the fuel rod is significantly lower than that of Comparative Example 2; 2. Compared with Compared with Example 1, the surface hardness is significantly improved; 3. Using 2 μm pure Zr as the working layer, after corroding in water vapor at 1000°C for 60 minutes, the weight gain is about 500mg / dm 2 , The corrosion weight gain was reduced by more than 85% compared with Comparative Example 1.

[0041] Therefore, the coating of the invention significantly improves the corrosion resistance of the zirconium alloy cladding tube, and significantly reduces the neutron economic loss of the ...

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Abstract

The invention discloses a high-temperature steam corrosion resistant coating for a zirconium alloy cladding tube. Two layers of the coating are arranged outside the zirconium alloy cladding tube, andthe first layer of the coating close to the zirconium alloy cladding tube is a metal transition layer or a ceramic transition layer; and the second layer of the coating is arranged on the metal transition layer, the second layer of the coating is a working layer, and the working layer is a zirconium coating or a zirconium oxide coating or a zirconium and zirconium oxide double-layer coating. By the adoption of the coating, the corrosion rate of the zirconium alloy cladding in 1000 DEG C steam can be reduced by 85% or above compared with that of an uncoated cladding, the turning acceleration phenomenon of oxidation is avoided, and the zirconium alloy cladding has more excellent LOCA accident resistance. Compared with a pure Cr coating, the coating remarkably improves the neutron economy ofthe cladding.

Description

technical field [0001] The invention belongs to the technical field of reactor nuclear fuel zirconium alloy cladding surface modification technology, in particular to a coating coated on the surface of a zirconium alloy cladding tube to enhance its high-temperature steam corrosion resistance. Background technique [0002] The reactor uses rod-shaped nuclear fuel elements (hereinafter referred to as "fuel rods"). Fuel rods 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] Under accident conditions, the heat stored in the fuel pellets and the decay heat of fission products will cause the temperature of the zirconium alloy cladding to rise rapidly, and then the zirconium alloy will undergo oxidation and exothermic reactions with wate...

Claims

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Application Information

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IPC IPC(8): G21C3/06G21C3/07
CPCG21C3/06G21C3/07Y02E30/30
Inventor 崔严光卢俊强李崇陈芙梁陆辉陈向阳周云清
Owner SHANGHAI NUCLEAR ENG RES & DESIGN INST CO LTD
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