Performance-modified oxide ceramic core body for thermal neutron reactor, and preparation method thereof

An oxide ceramic and reactor technology, which is applied in the fields of reactor fuel material, nuclear power generation, and greenhouse gas reduction, etc., can solve the problems of control affecting reactivity, reducing the reactivity value of neutron absorbers, affecting the safety and controllability of reactors, etc. Achieve the effect of improving thermal conductivity, improving moderation performance, and good moderation performance

Active Publication Date: 2013-07-24
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

[0004] Since most reactors are designed with UO 2 fuel, and the MOX fuel loaded later needs to maintain structural compatibility, so it is difficult to alleviate the above adverse phenomena through structural design changes
In addition, the reactivity value of the neutron absorber is closely related to the neutron energy spectrum. In some reactors loaded with MOX fuel, due to the hard neutron energy spectrum, the reactivity value of the neutron absorber decreases, which affects the reactivity. control, thereby affecting the safety and controllability of the reactor

Method used

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  • Performance-modified oxide ceramic core body for thermal neutron reactor, and preparation method thereof
  • Performance-modified oxide ceramic core body for thermal neutron reactor, and preparation method thereof

Examples

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Effect test

Embodiment 1

[0027] Taking the uranium-plutonium mixed oxide fuel core (MOX) fuel core for pressurized water reactor as an example, the present invention will be further explained.

[0028] MOX contains Pu extracted from spent fuel. Using MOX fuel core as PWR fuel can improve the utilization rate of nuclear fuel; but PuO 2 The existence of the MOX core makes the thermal conductivity of the MOX core lower than that of ordinary UO 2 Core, the core temperature is higher, which affects the core operating performance; at the same time, the introduction of Pu will harden the core neutron energy spectrum, thereby reducing the reactivity value of the neutron absorber.

[0029] The invention adds a second phase material with high thermal conductivity and slowing effect to MOX. The second phase material is ultra-high thermal conductivity oxide material BeO. The addition ratio is shown in Table 1 below. BeO forms a continuous phase in MOX, such as figure 1 As shown, an improved performance oxide ceramic co...

Embodiment 2

[0042] The improved performance oxide ceramic core for thermal neutron reactors according to the present invention and the preparation method thereof are as follows:

[0043] (1) Preparation of raw materials: oxide ceramic core powder and second phase material powder are shown in Table 3;

[0044] table 3

[0045] ingredient Proportion (mass percentage) UO2 90.4% PuO 2 6.6% BeO 3.0%

[0046] (2) Mixing: the oxide ceramic core powder and the second phase material powder described in step (1) are mixed and ball milled, and the ball milling time is 45 minutes; before the mixed ball milling, the oxide ceramic described in step (1) The core powder is pre-fired for 3h;

[0047] (3) Compaction: the powder obtained by mixing in step (2) is calmly pressed into a green compact with a pressure of 200MPa;

[0048] (4) Sintering: The green body obtained in step (3) is sintered in a sintering furnace at a sintering temperature of 1750°C for 2 hours. The sintering atmosphere is a mixed gas of ...

Embodiment 3

[0051] The improved performance oxide ceramic core for thermal neutron reactors according to the present invention and the preparation method thereof are as follows:

[0052] (1) Preparation of raw materials: oxide ceramic core powder and second phase material powder are shown in Table 4;

[0053] Table 4

[0054] ingredient Proportion (mass percentage) UO2 88.4%

[0055] PuO 2 10.6% BeO 1.0%

[0056] (2) Mixing: the oxide ceramic core powder and the second phase material powder described in step (1) are mixed and ball milled, and the ball milling time is 2h; before mixing ball milling, the oxide ceramic described in step (1) The core powder is pre-fired, and the pre-fire time is 5h;

[0057] (3) Compaction: the powder obtained by mixing in step (2) is calmly pressed into a green compact with a pressure of 200MPa;

[0058] (4) Sintering: Place the green body obtained in step (3) for sintering in a sintering furnace at a sintering temperature of 1700°C for 1 hour. The sinterin...

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Abstract

The present invention provides a performance-modified oxide ceramic core body for a thermal neutron reactor, and a preparation method thereof. According to the present invention, a second phase material is added to an oxide ceramic core body, and the added second phase material forms a continuous phase in the oxide ceramic core body to obtain a performance-modified oxide ceramic core body, wherein the mass of the second phase material is 0.3-15% of the total mass of the performance-modified oxide ceramic core body; the preparation steps comprise: raw material preparation, mixing, green compacting and sintering; compared with the common core body with no specified component addition, the performance-modified oxide ceramic core body for the thermal neutron reactor has a low temperature; and the fuel assembly adopting the core body has the following characteristics that: a neutron energy spectrum is softened, a ratio of a fast neutron flux to a thermal neutron flux in the assembly is reduced by about 35%, and a reactivity value of a neutron absorption body is increased by about 25%.

Description

Technical field [0001] The invention relates to the field of nuclear fuel, in particular to an oxide ceramic core with improved performance for thermal neutron reactors and a preparation method thereof. Background technique [0002] The nuclear fuel core has the form of metal fuel, dispersion fuel, ceramic fuel and so on. Among them, metal fuels are difficult to use at higher operating temperatures in power reactors due to their relatively low phase transition temperature and melting point, and the dimensional changes caused by irradiation growth are relatively large. Dispersed fuels are in order to achieve certain fissile nuclide nuclei. Density needs to increase the enrichment of the fuel; ceramic fuels are widely used in power reactors due to their relatively stable size, higher melting point, and lower enrichment. [0003] A serious disadvantage of the ceramic fuel core is its poor thermal conductivity, which makes the temperature gradient between the central and peripheral pa...

Claims

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Application Information

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Patent Type & Authority Applications(China)
IPC IPC(8): C04B35/01C04B35/622G21C3/62
CPCY02E30/34Y02E30/38Y02E30/30
Inventor 丁阳李继威毕光文周勤汤春桃朱丽兵陈磊李志勇
Owner SHANGHAI NUCLEAR ENG RES & DESIGN INST CO LTD
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