WO2019231046A1 - Granulés de dioxyde d'uranium ayant une excellente propriété d'adsorption des gaz de fission et procédé de fabrication associé - Google Patents

Granulés de dioxyde d'uranium ayant une excellente propriété d'adsorption des gaz de fission et procédé de fabrication associé Download PDF

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Publication number
WO2019231046A1
WO2019231046A1 PCT/KR2018/009386 KR2018009386W WO2019231046A1 WO 2019231046 A1 WO2019231046 A1 WO 2019231046A1 KR 2018009386 W KR2018009386 W KR 2018009386W WO 2019231046 A1 WO2019231046 A1 WO 2019231046A1
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Prior art keywords
uranium dioxide
additive
sio
sintered body
sintered
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PCT/KR2018/009386
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English (en)
Korean (ko)
Inventor
임광영
정태식
나연수
이승재
유종성
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한전원자력연료 주식회사
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Publication of WO2019231046A1 publication Critical patent/WO2019231046A1/fr

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    • C—CHEMISTRY; METALLURGY
    • C01—INORGANIC CHEMISTRY
    • C01G—COMPOUNDS CONTAINING METALS NOT COVERED BY SUBCLASSES C01D OR C01F
    • C01G43/00—Compounds of uranium
    • C01G43/01—Oxides; Hydroxides
    • C01G43/025—Uranium dioxide
    • G—PHYSICS
    • G21—NUCLEAR PHYSICS; NUCLEAR ENGINEERING
    • G21C—NUCLEAR REACTORS
    • G21C21/00—Apparatus or processes specially adapted to the manufacture of reactors or parts thereof
    • G21C21/02—Manufacture of fuel elements or breeder elements contained in non-active casings
    • G—PHYSICS
    • G21—NUCLEAR PHYSICS; NUCLEAR ENGINEERING
    • G21C—NUCLEAR REACTORS
    • G21C3/00—Reactor fuel elements and their assemblies; Selection of substances for use as reactor fuel elements
    • G21C3/42—Selection of substances for use as reactor fuel
    • G21C3/58—Solid reactor fuel Pellets made of fissile material
    • G21C3/62—Ceramic fuel
    • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
    • Y02E—REDUCTION OF GREENHOUSE GAS [GHG] EMISSIONS, RELATED TO ENERGY GENERATION, TRANSMISSION OR DISTRIBUTION
    • Y02E30/00—Energy generation of nuclear origin
    • Y02E30/30—Nuclear fission reactors

Definitions

  • the present invention relates to a sintered body containing an oxide additive in order to promote grain size growth of the sintered uranium dioxide sintered body used as a nuclear heat fuel and to increase nuclear fission gas adsorption performance, and a method of manufacturing the same.
  • Uranium dioxide sintered bodies used in nuclear power plants have been actively studied from the 1970s to the present for improving the performance.
  • Nuclear fuel suppliers ANF, AREVA (currently Framatome), and Westinghouse Atom, respectively, have found that Al 2 O 3 -SiO 2 , Cr 2 O 3 , Cr 2 O 3 -Al 2 O 3 The development has been completed and is currently licensed or under license for regulatory development.
  • the fuel rod damage caused by PCI occurs when the cladding tube and the sintered body come into contact with each other from 30 GWD / MTU or more. From this time, the sintered body exerts a mechanical deformation and causes breakage by applying an external force in the radial direction of the cladding.
  • the sintered bodies having the large grain microstructure as a result of the addition oxides cause plastic deformation of the sintered body itself before the deformation of the cladding, and solve the mutual stress with the cladding resulting from the volume expansion by heat.
  • the area of the grain boundary which is a passage through which various kinds of fission gases generated by the nuclear reaction, can be reduced, thereby reducing the rate of fission gas out of the sintered body.
  • the role of the PCI damage reduction sintering additive is basically to make the grains of the uranium dioxide sintered body large. This is the result of the oxide additive during sintering of uranium dioxide to promote the movement of uranium cations at the sintering temperature, this developed microstructure improves safety and power plant operating margin when burning in the furnace of a nuclear power plant (furnace).
  • uranium dioxide-based candidates include silicon carbide whiskers or composite materials in which diamond particles are dispersed in the uranium dioxide sintered body, and metal microcells in which a metal network is formed in the uranium dioxide base. These are all aimed at improving the thermal conductivity.
  • uranium dioxide sinters with large grains added with oxides are considered to be the most promising final candidates for the most feasible ATF sinters. There is.
  • Japanese Patent Nos. 263382 and 3999843 show that Al 2 O 3 and SiO 2 are added at 0.01 to 0.25% by weight in various ratios to obtain large grains, thereby obtaining a high creep rate.
  • Rare earth metal oxides are generally known to be added to refractory materials to serve to raise the glass transition temperature (T g ) or the melting point (T m ).
  • T g glass transition temperature
  • T m melting point
  • NBO non-bridging oxygen atoms
  • the present invention provides a uranium dioxide sintered body and a manufacturing method containing an additive capable of efficiently trapping cesium, a fissile material, by stably forming a liquid phase capable of promoting grain growth of uranium dioxide, which is a nuclear fuel used in a nuclear power plant.
  • the purpose is to do that.
  • the present invention in the uranium dioxide nuclear fuel sintered body, uranium dioxide; And it provides a uranium dioxide sintered body comprising a sintering additive consisting of La 2 O 3 , Al 2 O 3 , SiO 2 .
  • the sintering additive La 2 O 3 -Al 2 O 3 -SiO 2 to move the uranium ions quickly through the liquid phase obtained through the liquid phase to promote grain growth and is applied to the grain boundary sessile capacitive gas produced during combustion in the furnace always You can.
  • the additive may contain 0.05 to 0.15 parts by weight based on 100 parts by weight of uranium dioxide.
  • the additive may be a La 2 O 3 : Al 2 O 3 : SiO 2 mixed weight ratio of 1 to 2: 1 to 2: 7 to 8.
  • the present invention provides a method for producing a uranium dioxide fuel sintered body, comprising the steps of: (a) preparing an additive by mixing La 2 O 3 , Al 2 O 3 , SiO 2 ; (b) adding the additive to uranium dioxide powder and mixing the same to prepare a mixed powder; (c) compression molding the mixed powder to produce a molded body; And (d) provides a method for producing a uranium dioxide sintered body comprising the step of sintering the molded body in the sintering furnace during the reducing atmosphere.
  • the present invention adds lanthanum oxide (La 2 O 3 ), aluminum oxide (Al 2 O 3 ), silicon oxide (SiO 2 ) to uranium dioxide powder, which is a fuel sintered body, and is sintered in a weakly reducing atmosphere and stable at high temperatures. By forming a liquid phase, large crystal grains can be efficiently formed.
  • La 2 O 3 , Al 2 O 3 , SiO 2 may be mixed in a weight ratio of 1 to 2: 1 to 2: 7 to 8.
  • the additive may be added 0.05 to 0.15 parts by weight based on 100 parts by weight of uranium dioxide powder.
  • the step (d) may be performed at 1730 to 1780 ° C., and may maintain the hydrogen gas injection rate at 200 to 2,000 ml / min.
  • La 2 O 3 -Al 2 O 3 -SiO 2 in uranium dioxide By adding the sintering additive, the liquid phase produced during the sintering of the uranium dioxide sintered body accelerates the movement of grains and promotes grain growth, and the low vapor pressure of the liquid phase reduces the volatilization during sintering, thereby exhibiting an efficient additive performance.
  • the liquid phase surrounding the grain boundary can effectively adsorb cesium, a fission gas.
  • the sintered uranium dioxide sintered body can reduce PCI damage as well as improve safety margin in an accident scenario.
  • EDS 3 is an energy dispersive X-ray method of preparing a uranium dioxide sintered body containing 5 wt% La 2 O 3 -Al 2 O 3 -SiO 2 according to the sintered body manufacturing method of an embodiment of the present invention.
  • Spectroscopy is used to show the distribution of metal elements located in the microstructure.
  • FIG. 5 is a photograph taken by a microstructured optical microscope of a uranium dioxide sintered body to which Al 2 O 3 -SiO 2 is prepared according to a comparative example of the present invention (x 1,000 magnification).
  • Figure 6 shows the results of the quantitative analysis of the mixed powder used in one embodiment and Comparative Example in the present invention, and the Si element contained in the sintered body prepared in Example and Comparative Example using an inductively coupled plasma spectrometer .
  • the present invention is a uranium dioxide nuclear fuel sintered body, uranium dioxide; It comprises an additive consisting of lanthanum oxide (La 2 O 3 ), aluminum oxide (Al 2 O 3 ), silicon oxide (SiO 2 ), the additive contains 0.05 to 0.15 parts by weight relative to 100 parts by weight of uranium dioxide, La It provides a uranium dioxide sintered body characterized in that the mixed weight ratio of 2 O 3 : Al 2 O 3 : SiO 2 is 1-2: 1-2: 7-8.
  • the additive is composed of lanthanum oxide (La 2 O 3 ), aluminum oxide (Al 2 O 3 ), silicon oxide (SiO 2 ), forms a liquid phase at the sintering temperature to accelerate the material movement of uranium atoms to promote grain growth Promote In addition, it forms a film on the grain interface to adsorb the fission gas generated during combustion in the furnace of a nuclear power plant.
  • La 2 O 3 lanthanum oxide
  • Al 2 O 3 aluminum oxide
  • SiO 2 silicon oxide
  • the present invention is a method for producing a uranium dioxide fuel sintered body, (a) La 2 O 3 , Al 2 O 3 , SiO 2 by mixing in a weight ratio of 1-2 to 1-2: 7 to 8 to prepare an additive Step (S11); (b) adding the additive to 0.05 to 0.15 parts by weight based on 100 parts by weight of the uranium dioxide powder and mixing to prepare a mixed powder (S12); (c) compression molding the mixed powder to produce a molded product (S13); And (d) provides a method for producing a uranium dioxide sintered body comprising the step (S14) of heating the molded body at 1730 to 1780 °C in the sintering furnace in the reducing atmosphere.
  • step S11 is a step of mixing an additive used as uranium dioxide oxide, and the additive composition includes La 2 O 3 , Al 2 O 3 , and SiO 3 .
  • the ratio of the oxide additive in the step S11 is the composition range with the highest liquid fraction, as La 2 O 3 -Al 2 O 3 -SiO 2 equilibrium three-component state diagram of Figure 2, La 2 O 3 , Al 2 O 3 , SiO It adds in 3 ratio (weight ratio).
  • the mixing is performed homogeneously using a Turbula mixer capable of three-axis rotational mixing with a zirconia ball of 5 mm diameter.
  • step S11 only the additives are mixed first. This is to maintain the composition ratio between the additive powder which is mixed with the uranium dioxide which is the parent powder because the additive system is multicomponent.
  • the additive content is limited to 0.05 to 0.15 parts by weight relative to 100 parts by weight of uranium dioxide powder.
  • the addition of 0.05 wt% or more in the step S12 is to form a sufficient liquid phase.
  • the reason for not exceeding 0.15% by weight is to minimize the neutron economy deterioration due to the addition of elements having a high thermal neutron absorption cross-sectional area.
  • the amount of the additive is limited to 0.05 to 0.15 parts by weight based on 100 parts by weight of the uranium dioxide powder in order to apply the liquid phase containing SiO 2 to the crystal grains for growth up to 40 ⁇ m or more and high fission material adsorption.
  • the mixing is carried out for three hours using a Turbula mixer with a zirconia ball of diameter 5 mm for three hours of rotating homogeneous mixing.
  • step S13 as a step of compacting the mixed additive powder and uranium dioxide powder, a mixed powder is added to a molding mold and a molded body is manufactured at a pressure of 2.5 ton / cm 2 .
  • step S14 as a step of sintering the manufactured molded body, 100% hydrogen gas is injected at 200 ml / min to 2,000 ml / min at a temperature in the range of 1700 to 1780 ° C, and the sintering is performed for 3 to 5 hours.
  • 100% hydrogen gas is injected at 200 ml / min to 2,000 ml / min at a temperature in the range of 1700 to 1780 ° C, and the sintering is performed for 3 to 5 hours.
  • 100% hydrogen gas is injected at 200 ml / min to 2,000 ml / min at a temperature in the range of 1700 to 1780 ° C, and the sintering is performed for 3 to 5 hours.
  • the reason for not exceeding 2,000 ml / min is to lower the pressure loaded inside by the clogging phenomenon of condensed water generated in the gas outlet by a small amount of steam discharged during sintering.
  • a large grain sintered body having an average grain size of 40 ⁇ m or more can be produced.
  • the liquid phase can be formed in the present sintering process.
  • the elements constituting the secondary phase in the liquid phase state obtained by containing the additive were identified.
  • the lanthanum surrounding the uranium dioxide grains in the sintered compact containing 5 parts by weight of the La 2 O 3 -Al 2 O 3 -SiO 2 additive in an amount of 5 parts by weight relative to 100 parts by weight of the uranium dioxide powder The signal from the area
  • La 2 O 3 , Al 2 O 3 , SiO 2 additives were mixed in three dimensions homogeneously for 4 hours using a Turbula mexer with a 5 mm zirconia ball diameter ( ⁇ ) at a weight ratio of 1: 1: 8. 0.1 parts by weight of the mixed additive was added to 100 parts by weight of uranium dioxide powder, mixed for 4 hours using a Turbula mixer, and then pressed at 3.5 ton / cm 2 to prepare a molded product.
  • the molded body was heated to 1730 ° C. at a rate of 5 ° C./min, and sintered at 1730 ° C. for 4 hours.
  • the sintering atmosphere was controlled by injecting 100% hydrogen gas at a rate of 250 ml / min.
  • uranium dioxide sintered body in which 0.09 parts by weight of an additive mixed with a weight ratio of 1: 8 was added to 100 parts by weight of uranium dioxide powder was prepared in the same manner as in the above example.
  • the linear cross-section method was used to measure the grain size, and the grain size was measured as an average size of 45.5 ⁇ m larger than about 9 ⁇ m of a typical uranium dioxide sintered body.
  • the grain size was measured with an average grain size of 21.5 ⁇ m.
  • the Example shows a grain size about twice as large as that of the sintered compact to which 0.09 parts by weight of Al 2 O 3 -SiO 2 additive of the Comparative Example was added.
  • ICP Inductively Coupled Plasma Spectrometer
  • Figure 6 shows the results of measuring the content of the silicon metal element present in the powder used in the Examples and Comparative Examples and the sintered uranium dioxide prepared in Examples and Comparative Examples.
  • Si content in SiO 2 added at 800 ppm was 372.8 ppm, which is 46.6%, and both Examples and Comparative Examples showed Si content close to 370 ppm.
  • the sintered body it was measured as 320.7 and 130.7ppm, respectively, and it was found that Si was volatilized by about 50ppm and 240ppm. Therefore, the sintered compact of the Example is excellent in volatilization resistance about 4.8 times compared with the sintered compact of the comparative example.

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  • Engineering & Computer Science (AREA)
  • Physics & Mathematics (AREA)
  • Chemical & Material Sciences (AREA)
  • Plasma & Fusion (AREA)
  • General Engineering & Computer Science (AREA)
  • High Energy & Nuclear Physics (AREA)
  • Organic Chemistry (AREA)
  • Manufacturing & Machinery (AREA)
  • Ceramic Engineering (AREA)
  • Life Sciences & Earth Sciences (AREA)
  • General Life Sciences & Earth Sciences (AREA)
  • Geology (AREA)
  • Inorganic Chemistry (AREA)
  • Inorganic Compounds Of Heavy Metals (AREA)
  • Solid-Sorbent Or Filter-Aiding Compositions (AREA)

Abstract

La présente invention concerne des granulés contenant un additif d'oxyde pour favoriser la croissance de la taille de grains cristallins de granulés de dioxyde d'uranium utilisés comme combustible nucléaire et augmenter les performances d'adsorption des gaz de fission, et un procédé de fabrication associé. L'additif de frittage La2O3-Al2O3-SiO2 est ajouté à du dioxyde d'uranium, de sorte qu'un liquide généré lors du frittage des granulés de dioxyde d'uranium accélère un transfert de masse pour favoriser la croissance de grains cristallins et qu'une faible pression de vapeur du liquide entraîne moins de volatilisation au cours du frittage, et ainsi l'additif peut exercer une performance efficace, et en résultat, le liquide encerclant les limites de grains cristallins peut adsorber efficacement le césium gazeux de fission.
PCT/KR2018/009386 2018-05-29 2018-08-16 Granulés de dioxyde d'uranium ayant une excellente propriété d'adsorption des gaz de fission et procédé de fabrication associé WO2019231046A1 (fr)

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KR20180061268 2018-05-29

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Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN114509464A (zh) * 2020-11-17 2022-05-17 中核建中核燃料元件有限公司 一种二氧化铀芯块平均晶粒尺寸非破坏性检测方法
EP3843108A4 (fr) * 2019-09-25 2022-06-01 Kepco Nuclear Fuel Co., Ltd. Pastilles de dioxyde d'uranium de combustible nucléaire ayant une capacité de capture de gaz de fission améliorée et leur procédé de fabrication

Citations (4)

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JPH0527069A (ja) * 1991-07-18 1993-02-05 Nippon Nuclear Fuel Dev Co Ltd 核燃料ペレツトの製造方法および核燃料ペレツト
KR100521638B1 (ko) * 2002-10-02 2005-10-13 한국원자력연구소 ＳｉＯ2-ＣａＯ-Ｃｒ2Ｏ3 첨가제를 함유한 이산화우라늄계핵연료 소결체 및 그 제조방법
KR20110059231A (ko) * 2009-11-27 2011-06-02 한국원자력연구원 Ｔｉ-화합물 및 Ｍｇ-화합물이 첨가된 우라늄산화물 핵연료 소결체 및 이의 제조 방법
KR20170101083A (ko) * 2016-02-25 2017-09-05 한전원자력연료 주식회사 큰 결정립을 갖는 우라늄산화물 핵연료 소결체 조성물 및 제조 방법

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JPH0527069A (ja) * 1991-07-18 1993-02-05 Nippon Nuclear Fuel Dev Co Ltd 核燃料ペレツトの製造方法および核燃料ペレツト
KR100521638B1 (ko) * 2002-10-02 2005-10-13 한국원자력연구소 ＳｉＯ2-ＣａＯ-Ｃｒ2Ｏ3 첨가제를 함유한 이산화우라늄계핵연료 소결체 및 그 제조방법
KR20110059231A (ko) * 2009-11-27 2011-06-02 한국원자력연구원 Ｔｉ-화합물 및 Ｍｇ-화합물이 첨가된 우라늄산화물 핵연료 소결체 및 이의 제조 방법
KR20170101083A (ko) * 2016-02-25 2017-09-05 한전원자력연료 주식회사 큰 결정립을 갖는 우라늄산화물 핵연료 소결체 조성물 및 제조 방법

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Title
ALI R. MASSIH, EFFECTS OF ADDITIVES ON URANIUM DIOXIDE FUEL BEHAVIOR, REPORT NUMBER: 2014:21, January 2014 (2014-01-01), ISSN: 2000-0456, Retrieved from the Internet <URL:https://www.stralsakerhetsmyndigheten.se/en/publications/reports/safety-at-nuclear-power-plants/2014/201421> *

Cited By (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
EP3843108A4 (fr) * 2019-09-25 2022-06-01 Kepco Nuclear Fuel Co., Ltd. Pastilles de dioxyde d'uranium de combustible nucléaire ayant une capacité de capture de gaz de fission améliorée et leur procédé de fabrication
US11742097B2 (en) 2019-09-25 2023-08-29 Kepco Nuclear Fuel Co., Ltd. Uranium-dioxide pellet for nuclear fuel having improved nuclear-fission-gas adsorption property, and method of manufacturing same
CN114509464A (zh) * 2020-11-17 2022-05-17 中核建中核燃料元件有限公司 一种二氧化铀芯块平均晶粒尺寸非破坏性检测方法

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