Coating for improving corrosion resistance of zirconium alloy cladding tube by doping stabilized zirconium oxide

A technology for stabilizing zirconia and cladding tubes, used in coatings, anti-corrosion coatings, etc., can solve the problems of loss of protective effect of the oxide layer, cracking of the oxide layer, loss of protection, etc., and achieve excellent resistance to LOCA accidents and extended retention strength. time, the effect of reducing hydrogen production

Inactive Publication Date: 2021-08-20
SHANGHAI NUCLEAR ENG RES & DESIGN INST CO LTD
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

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Problems solved by technology

Among them, Zr is oxidized to ZrO 2 , in the monoclinic phase (m-ZrO 2 ) is a stable phase, and the monoclinic phase has a large volume expansion, causing the oxide layer to bulge and rupture and lose its protective effect; ZrO 2 Monoclinic phase (m-ZrO 2 ) to the tetragonal phase (t-ZrO 2 ) phase transition, the phase transition stress causes the oxide layer to crack and lose its protection

Method used

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  • Coating for improving corrosion resistance of zirconium alloy cladding tube by doping stabilized zirconium oxide
  • Coating for improving corrosion resistance of zirconium alloy cladding tube by doping stabilized zirconium oxide

Examples

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Embodiment 1

[0020] see figure 2 In this example, the surface of the zirconium alloy cladding 2 is coated with tetragonal doped stabilized zirconia formed by pure Cr as the transition layer 6 and zirconia doped with 5% yttrium oxide as the working layer 5 .

[0021] The characteristics of this example are: 1. Cr is used as the transition layer 6, which prevents the diffusion of oxygen in the working layer to the zirconium alloy matrix under high temperature conditions; 2. The zirconia doped with 5% yttrium oxide is stable in the tetragonal phase Phase; 3. Doped stabilized zirconia is used as the working layer 5, and the working layer does not undergo phase change at a room temperature above 25°C, which effectively prevents water vapor from eroding the zirconium alloy cladding 2; 4. The Cr transition layer is only 1-2 μm , the fuel assembly neutron economy loss is very low.

[0022] Therefore, the coating composed of the transition layer 6 and the working layer 5 in this example significa...

Embodiment 2

[0024] In this example, CrN is coated on the surface of the zirconium alloy cladding 2 as a transition layer 6, and cubic phase doped stabilized zirconia formed by doping 10% yttrium oxide in zirconia is used as a working layer.

[0025] The characteristics of this example are: 1. CrN is used as the transition layer 6, which prevents the oxygen element in the working layer 5 from diffusing to the zirconium alloy matrix under high temperature conditions; 2. The zirconia doped with 10% yttrium oxide has a cubic phase Stable phase; 3. Doped stabilized zirconia is used as the working layer 5, and the working layer does not undergo phase change at a room temperature above 25°C, which effectively prevents water vapor from eroding the zirconium alloy cladding 2; 4. The CrN transition layer 6 is only 1 ~2μm, the fuel assembly neutron economy loss is very low.

[0026] Therefore, the coating composed of the transition layer 6 and the working layer 5 in this example significantly improv...

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Abstract

The invention relates to the technical field of zirconium alloy surface coatings for light-water reactors, in particular to a coating for improving the corrosion resistance of a zirconium alloy cladding tube by doping stabilized zirconium oxide, which comprises a transition layer and a working layer sequentially coating the outer surface of the cladding tube. The transition layer adopts a single-layer pure component containing the following elements or an alloy containing the following elements or a compound containing the following elements: Zr, Cr, N, Si, C and Al; the thickness of the transition layer is 0.1-10 mum; the working layer adopts doped stable zirconium oxide formed by doping yttrium oxide, calcium oxide, magnesium oxide, aluminum oxide or cerium oxide in zirconium oxide, and the mass fraction of zirconium oxide is greater than 87%; and the thickness range of the working layer is 0.1-10 mum. Compared with an existing zirconium alloy surface coating technology, the coating has the advantages that the neutron economy is more excellent, and the high-temperature steam corrosion resistance of the coating zirconium alloy cladding tube at the temperature of 1205 DEG C or above is enhanced.

Description

technical field [0001] The invention relates to the technical field of zirconium alloy surface coatings for light water reactors, in particular to a coating that uses doped stabilized zirconia to improve the corrosion resistance of zirconium alloy cladding tubes. Background technique [0002] Light water reactor is the main reactor type of nuclear power plant, using rod-shaped nuclear fuel elements, hereinafter referred to as "fuel rods". see figure 1 As shown, the fuel rod consists of a short cylindrical UO 2 The fuel pellet 4, the zirconium alloy cladding 2, the end plug 1, and the compression spring 3 of the air storage chamber are composed of a certain gap between the fuel pellet and the cladding, and the fuel element is filled with inert gas. [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 ...

Claims

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Application Information

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Patent Type & Authority Applications(China)
IPC IPC(8): C09D5/10C09D1/00C09D5/08
CPCC09D1/00C09D5/08C09D5/10
Inventor 崔严光李崇卢俊强周云清恽迪马大衍
Owner SHANGHAI NUCLEAR ENG RES & DESIGN INST CO LTD
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