KR100331483B1 - Method of manufacturing oxide fuel pellets containing neutron-absorbing materials - Google Patents
Method of manufacturing oxide fuel pellets containing neutron-absorbing materials Download PDFInfo
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- KR100331483B1 KR100331483B1 KR1019990020120A KR19990020120A KR100331483B1 KR 100331483 B1 KR100331483 B1 KR 100331483B1 KR 1019990020120 A KR1019990020120 A KR 1019990020120A KR 19990020120 A KR19990020120 A KR 19990020120A KR 100331483 B1 KR100331483 B1 KR 100331483B1
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- 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
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- C04B2235/00—Aspects relating to ceramic starting mixtures or sintered ceramic products
- C04B2235/02—Composition of constituents of the starting material or of secondary phases of the final product
- C04B2235/30—Constituents and secondary phases not being of a fibrous nature
- C04B2235/32—Metal oxides, mixed metal oxides, or oxide-forming salts thereof, e.g. carbonates, nitrates, (oxy)hydroxides, chlorides
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- C04B2235/3231—Refractory metal oxides, their mixed metal oxides, or oxide-forming salts thereof
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- C04B2235/00—Aspects relating to ceramic starting mixtures or sintered ceramic products
- C04B2235/02—Composition of constituents of the starting material or of secondary phases of the final product
- C04B2235/30—Constituents and secondary phases not being of a fibrous nature
- C04B2235/34—Non-metal oxides, non-metal mixed oxides, or salts thereof that form the non-metal oxides upon heating, e.g. carbonates, nitrates, (oxy)hydroxides, chlorides
- C04B2235/3418—Silicon oxide, silicic acids, or oxide forming salts thereof, e.g. silica sol, fused silica, silica fume, cristobalite, quartz or flint
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- C04B35/00—Shaped ceramic products characterised by their composition; Ceramics compositions; Processing powders of inorganic compounds preparatory to the manufacturing of ceramic products
- C04B35/622—Forming processes; Processing powders of inorganic compounds preparatory to the manufacturing of ceramic products
- C04B35/626—Preparing or treating the powders individually or as batches ; preparing or treating macroscopic reinforcing agents for ceramic products, e.g. fibres; mechanical aspects section B
- C04B35/63—Preparing or treating the powders individually or as batches ; preparing or treating macroscopic reinforcing agents for ceramic products, e.g. fibres; mechanical aspects section B using additives specially adapted for forming the products, e.g.. binder binders
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- C04B35/00—Shaped ceramic products characterised by their composition; Ceramics compositions; Processing powders of inorganic compounds preparatory to the manufacturing of ceramic products
- C04B35/622—Forming processes; Processing powders of inorganic compounds preparatory to the manufacturing of ceramic products
- C04B35/64—Burning or sintering processes
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- 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
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- Y02E—REDUCTION OF GREENHOUSE GAS [GHG] EMISSIONS, RELATED TO ENERGY GENERATION, TRANSMISSION OR DISTRIBUTION
- Y02E30/00—Energy generation of nuclear origin
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Abstract
본 발명은 중성자 흡수물질을 함유한 산화물 핵연료 소결체의 제조방법에 관한 것으로, 그 목적은 UO2분말과 Gd2O3분말의 혼합분말에 소결촉진제를 첨가함으로써, 상기 혼합분말을 분쇄하지 않고 성형ㆍ소결하여 고밀도와 큰 결정립을 동시에 갖는 (U,Gd)O2핵연료 소결체 제조방법을 제공하는데 있다.BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for producing an oxide fuel sintered body containing a neutron absorbing material, the object of which is to form and pulverize the mixed powder without adding a sintering accelerator to the mixed powder of UO 2 powder and Gd 2 O 3 powder. It is to provide a method for producing a (U, Gd) O 2 fuel sintered body having a high density and a large grain at the same time by sintering.
본 발명의 방법은 UO2분말과 Gd2O3분말의 혼합분말 또는 UO2분말과 Er2O3분말의 혼합분말에 크롬산화물과 실리콘산화물을 첨가하거나 마그네슘산화물과 실리콘산화물을 첨가하여 혼합한 후 혼합분말을 압축성형 하여 성형체를 제조하고 상기 성형체를 환원성 기체분위기에서 가열하여 1600℃∼1800℃ 온도범위에서 1시간 이상 유지하여 소결하는 산화물 핵연료 소결체의 제조방법으로서, 상기 소결체는 0.005∼0.025 중량%의 크롬과 0.002∼0.025 중량%의 실리콘을 같이 함유하거나 또는 0.005∼0.020 중량%의 마그네슘과 0.002∼0.025 중량%의 실리콘을 같이 함유한 것이 방법의 요지이다.In the method of the present invention, after mixing chromium oxide and silicon oxide or adding magnesium oxide and silicon oxide to the mixed powder of UO 2 powder and Gd 2 O 3 powder or the mixed powder of UO 2 powder and Er 2 O 3 powder A method of manufacturing an oxide fuel sintered compact in which a mixed powder is compression molded to produce a molded body, and the molded body is heated in a reducing gas atmosphere and maintained at 1600 ° C. to 1800 ° C. for at least 1 hour, wherein the sintered compact is 0.005 to 0.025 wt% And chromium and 0.002 to 0.025% by weight of silicon together or 0.005 to 0.020% by weight of magnesium together with 0.002 to 0.025% by weight of silicon.
Description
본 발명은 산화물 핵연료 소결체의 제조방법에 관한 것으로, 특히 중성자 흡수물질을 함유한 산화물 핵연료 소결체의 제조방법에 관한 것이다.The present invention relates to a method for producing an oxide fuel sintered body, and more particularly to a method for producing an oxide fuel sintered body containing a neutron absorbing material.
원자로에서 사용되는 핵연료봉은 지르칼로이 피복관에 이산화우라늄(UO2) 핵연료 소결체를 장입하여 밀봉한 형태이다. 우라늄 중에는 핵분열 물질인 U235가1~5 중량% 포함되어 있는데, 원자로 안에서 U235가 중성자에 의하여 붕괴하면서 핵분열 에너지를 발생하며, 이 열은 핵연료봉 사이를 흐르는 냉각수에 전달된다.Nuclear fuel rods used in nuclear reactors are sealed by inserting sintered uranium dioxide (UO 2 ) fuel into a zircaloy cladding tube. There are 235 U of fissile material during the uranium contained 1-5% by weight, 235 U fission occurs, the energy and the collapse by the neutrons in the reactor, and this heat is transferred to the cooling water flowing between the fuel rods.
상기 UO2소결체는 UO2분말을 압축성형 하여 성형체를 제조한 후, 이것을 환원성 기체분위기에서 약 1700℃ 온도로 2~4시간 동안 소결하여 제조한다.The UO 2 sintered compact is produced by compression molding UO 2 powder to prepare a compact, and then sintering the same at a temperature of about 1700 ° C. for 2-4 hours in a reducing gas atmosphere.
원자로 내에는 UO2핵연료 외에도 중성자 흡수용으로 주로 '가돌리니움(Gd)을 함유한 UO2[(U,Gd)O2] 핵연료가 함께 사용된다.In addition to the UO 2 fuel, UO 2 [(U, Gd) O 2 ] fuel containing Gadolinium (Gd) is used in the reactor.
상기 (U,Gd)O2소결체는 통상적으로 UO2분말과 Gd2O3분말을 함께 분쇄하고, 이 분쇄 분말로부터 UO2소결체의 제조공정과 같은 방법으로 성형 및 소결하여 소결체를 제조한다.The (U, Gd) O 2 sintered compact is usually pulverized together with UO 2 powder and Gd 2 O 3 powder, and molded and sintered from the pulverized powder in the same manner as in the manufacturing process of the UO 2 sintered compact to prepare a sintered compact.
전술한 (U,Gd)O2소결체 제조 공정이 UO2소결체 제조공정과 다른 점은 분말분쇄 공정이 추가된다는 것이다. 하지만 분말분쇄 공정에서는 일반적으로 방사선을 띤 미세한 분말이 비산할 수 있기 때문에 작업환경이 나빠진다는 문제점이 있다.The difference between the above-mentioned (U, Gd) O 2 sintered body manufacturing process and the UO 2 sintered body manufacturing process is that a powder grinding process is added. However, in the powder grinding process, there is a problem in that the working environment worsens because the fine powder with radiation may scatter.
그렇지만 분말분쇄 공정 없이 UO2분말과 Gd2O3분말의 혼합분말로부터 (U,Gd)O2소결체를 제조하게 되면, 소결체의 밀도가 매우 낮아지기 때문에 기술시방서의 밀도(93.5%~96.5%)를 만족하지 못하며, 또한 결정립 크기도 작아지게 된다는 문제점이 있다.However, if the (U, Gd) O 2 sintered body is manufactured from the mixed powder of UO 2 powder and Gd 2 O 3 powder without powder grinding process, the density of the sintered body becomes very low, so the density of the technical specification (93.5% ~ 96.5%) is reduced. There is a problem that it is not satisfied and the grain size also becomes small.
상기 단점을 극복하는 기술로는 한국특허 공고 92-286에서 UO2와 Gd2O3의 혼합분말에 Al을 5∼500 중량 ppm 또는 Ti를 5∼50 중량 ppm 첨가하여 (U,Gd)O2소결체 밀도를 증가시키는 방법이 알려져 있다.As a technique for overcoming the above disadvantages, in Korean Patent Publication 92-286, by adding 5 to 500 ppm by weight of Al or 5 to 50 ppm by weight of Ti to the mixed powder of UO 2 and Gd 2 O 3 (U, Gd) O 2 A method of increasing the sintered compact is known.
핵연료를 원자로 안에서 연소할 때 발생하는 핵분열 기체(제논,크립톤)는 결정립 크기가 작을수록 소결체 밖으로 많이 방출되고, 따라서 핵연료의 성능 및 수명을 제한하게 된다.Nuclear fission gases (xenon, krypton) generated when burning nuclear fuel in a reactor are released more out of the sintered body with a smaller grain size, thereby limiting the performance and life of the fuel.
핵연료 성능의 관점에서는 핵연료 소결체가 큰 결정립을 갖는 것이 유리한데 (U,Gd)O2소결체의 결정립 크기를 증가시킬 수 있는 기술이 알려져 있다.From the viewpoint of nuclear fuel performance, it is advantageous for the fuel sintered body to have large grains, but a technique for increasing the grain size of the (U, Gd) O 2 sintered body is known.
이러한 기술로는 일본 특허 공개 소64-29796에는 UO2와 Gd2O3의 혼합분말에 Cr2O3를 0.1∼0.3 중량% 첨가하여 1600℃ 이하에서 10∼20시간 소결하는 소결체 제조방법이 공개되었다.As such a technique, Japanese Patent Application Laid-Open No. 64-29796 discloses a method for producing a sintered body in which 0.1 to 0.3 wt% of Cr 2 O 3 is added to a mixed powder of UO 2 and Gd 2 O 3 and sintered at 1600 ° C. for 10 to 20 hours. It became.
또 일본 특허 공개 소62-36589에는 UO2와 Gd2O3의 혼합분말에 TiO2를 0.5 중량% 이내 또는 Nb2O5를 1.0 중량% 이내로 첨가하여 결정립 크기를 증가시킨 결과가 공개되었다.In addition, Japanese Patent Application Laid-Open No. 62-36589 discloses a result of increasing the grain size by adding TiO 2 to within 0.5% by weight or Nb 2 O 5 to within 1.0% by weight of a mixed powder of UO 2 and Gd 2 O 3 .
핵연료 소결체에 첨가하는 소결촉진제의 종류 및 첨가범위가 ASTM UO2소결체 기술시방서에서 허용하는 한계내에서 도출되지 않으면, 그 소결체는 노내 시험을 통하여 안전성을 입증하여야 하므로 개발에 많은 비용과 시간이 필요하므로 경제적이지 못하다.If the type and range of sintering accelerator added to the nuclear fuel sintered body are not derived within the limits allowed by the ASTM UO 2 sintered body technical specification, the sintered body must be proved to be safe through in-house testing, which requires a lot of cost and time for development. Not economical
그러나 소결촉진제의 종류와 첨가범위가 ASTM UO2소결체 기술시방서에서 허용하는 한계내에서 도출하면 노내 시험을 거치지 않고 비교적 쉽게 개발을 완료할수 있어 경제적이다.However, if the type and range of sintering accelerator are derived within the limits allowed by the ASTM UO 2 sintered body technical specification, it is economical because the development can be completed relatively easily without undergoing the furnace test.
ASTM UO2소결체 기술시방서에는 Cr이 250중량 ppm, Si은 250중량 ppm, Mg은 200중량 ppm 으로 제한하고 있으며 Ti 및 Nb는 허용 원소가 아니다.ASTM UO 2 sintered technical specifications limit 250 ppm by weight of Cr, 250 ppm by weight of Si, and 200 ppm by weight of Mg. Ti and Nb are not acceptable elements.
일본 특허 공개 소64-29796은 Cr2O3함량이 ASTM UO2소결체 기술시방서에서 허용하는 범위 이상이며, 또 일본 특허 공개 소62-36589는 첨가된 소결촉진제가 ASTM UO2소결체 기술시방서에서 허용하는 원소가 아니다.Japanese Patent Laid-Open No. 64-29796 has a Cr 2 O 3 content greater than that allowed by the ASTM UO 2 sintered body technical specification, and Japanese Patent Laid-Open No. 62-36589 shows that the added sintering accelerator is allowed by the ASTM UO 2 sintered body technical specification. It is not an element.
상기와 같은 문제점을 해결하기 위한 본 발명의 목적은 소결촉진제의 종류 및 첨가범위가 ASTM UO2소결체 기술시방서에서 허용하는 한계 이하로 사용하여 상기의 문제점을 해결하고, 이산화우라늄 분말과 중성자 흡수물질 분말의 혼합분말로부터 고밀도와 큰 결정립을 동시에 갖는 산화물 핵연료 소결체의 제조방법을 제공하도록 UO2분말과 Gd2O3분말의 혼합분말에 소결촉진제를 첨가함으로써, 상기 혼합분말을 분쇄하지 않고 성형ㆍ소결하여 고밀도와 큰 결정립를 동시에 갖는 (U,Gd)O2핵연료 소결체를 제조하는 제조방법을 제공하는데 있다.An object of the present invention for solving the above problems is to solve the above problems by using the type and range of sintering accelerator below the limit allowed by the ASTM UO 2 sintered body technical specifications, uranium dioxide powder and neutron absorbing material powder By adding a sintering accelerator to the mixed powder of UO 2 powder and Gd 2 O 3 powder to provide a method for producing an oxide fuel sinter having both high density and large grains from the mixed powder of It is to provide a manufacturing method for producing a (U, Gd) O 2 fuel sintered body having a high density and large grains at the same time.
도 1은 본 발명에서 제공하는 산화물 핵연료 소결체의 제조방법에 따른 가돌리니움 함유 우라늄산화물 (U,Gd)O2핵연료 소결체의 제조방법을 예시하는 공정 흐름도이다.1 is a process flow diagram illustrating a method for producing a gadolinium-containing uranium oxide (U, Gd) O 2 fuel sintered body according to the method for producing an oxide fuel sintered body provided in the present invention.
본 발명에 따른 (U,Gd)O2소결체 제조공정을 설명하면 다음과 같다.Referring to the (U, Gd) O 2 sintered body manufacturing process according to the present invention.
UO2분말과 Gd2O3분말의 혼합분말에 소결촉진제로서 크롬산화물(Cr2O3)과 실리콘산화물(SiO2)을 함께 첨가하거나 마그네슘산화물(MgO)과 실리콘산화물(SiO2)을 함께 첨가한 후, 균일하게 혼합하고 혼합분말을 성형 다이에 장입하고 압축성형 하여 성형체를 제조한다.To the mixed powder of UO 2 powder and Gd 2 O 3 powder, chromium oxide (Cr 2 O 3 ) and silicon oxide (SiO 2 ) are added together as a sintering accelerator or magnesium oxide (MgO) and silicon oxide (SiO 2 ) are added together. After that, the mixture is uniformly mixed, the mixed powder is charged into a molding die and compression molded to prepare a molded body.
상기 성형체를 환원성 기체분위기에서 1600℃∼1800℃ 온도 범위에서 1시간 이상 동안 소결하여 (U,Gd)O2소결체를 제조한다.The molded body is sintered in a reducing gas atmosphere at a temperature ranging from 1600 ° C. to 1800 ° C. for at least 1 hour to prepare a (U, Gd) O 2 sintered body.
상기 (U,Gd)O2소결체 제조공정 흐름을 도 1에 예시한다.The (U, Gd) O 2 sintered body manufacturing process flow is illustrated in FIG.
상기 혼합 분말중 Gd2O3분말의 비율은 약 15 중량% 이내이다.The proportion of Gd 2 O 3 powder in the mixed powder is within about 15% by weight.
또한 상기 소결체 중 크롬(Cr)양은 0.005∼0.025 중량% 이고 실리콘(Si)양은 0.002∼0.025 중량% 이거나 또는 마그네슘(Mg)양은 0.005∼0.02 중량% 이고 실리콘(Si)양은 0.002∼0.025 중량% 이다.In addition, the amount of chromium (Cr) in the sintered body is 0.005 to 0.025% by weight and the amount of silicon (Si) is 0.002 to 0.025% by weight, or the amount of magnesium (Mg) is 0.005 to 0.02% by weight and the amount of silicon (Si) is 0.002 to 0.025% by weight.
상기 환원성 기체는 수소기체이거나 수소기체에 질소, 불활성기체, 이산화탄소 그리고 수증기 중의 하나 이상의 기체를 혼합한 기체이다. 특히 이산화탄소나 수증기의 양이 많아지면 (U,Gd)O2소결체의 밀도가 높아지고 결정립 크기가 증가한다.The reducing gas is a hydrogen gas or a gas in which at least one gas of nitrogen, an inert gas, carbon dioxide, and water vapor is mixed with the hydrogen gas. In particular, as the amount of carbon dioxide or water vapor increases, the density of the (U, Gd) O 2 sintered body increases and the grain size increases.
유동성이 높은 UO2분말을 사용할 경우에는 UO2와 Gd2O3의 혼합분말을 직접 압축성형 하여 성형체를 제조하며, 반면 유동성이 낮은 UO2분말을 사용할 경우에는, UO2와 Gd2O3의 혼합분말을 과립으로 만들어서 유동성을 높인 후에 압축성형 하여 성형체를 제조한다.In case of using UO 2 powder with high flowability, the molded product is manufactured by directly compression molding the mixed powder of UO 2 and Gd 2 O 3 , whereas in case of using UO 2 powder with low fluidity, UO 2 and Gd 2 O 3 The mixed powder is made into granules to increase fluidity and then compression molding to prepare a molded body.
현재 산업적으로 공급되는 여러 종류의 UO2분말중에서 AUC(Ammonium Uranyl Carbonate) 공정으로 제조한 UO2분말의 유동성이 가장 좋아서 혼합분말의 직접성형이 가능하며, ADU(Ammonium Diuranate) 공정이나 DC(Dry Conversion) 공정으로 제조한 UO2분말은 유동성이 떨어지므로 혼합분말을 과립으로 만들어서 압축성형 한다.Current industry can be directly molded of different kinds of UO 2 powder good to among the fluidity of a UO 2 powder produced by the process AUC (Ammonium Uranyl Carbonate) powder mixture to be supplied to and, ADU (Ammonium Diuranate) process or a DC (Dry Conversion UO 2 powder prepared by) process is inferior in fluidity, so the powder is compressed into granulated powder.
이하 본 발명에 대하여 상세히 설명하면 다음과 같다.Hereinafter, the present invention will be described in detail.
상기에서 본 발명의 한정이유는 다음과 같다.The above reason of the present invention is as follows.
본 발명에서 소결촉진제로서 사용하는 Cr2O3나 MgO는 소결중에 UO2격자에 고용되면서 우라늄 공공을 만들거나, Cr2O3와 SiO2또는 MgO와 SiO2가 새로운 복합 산화물을 형성하여 소결중 물질이동을 빠르게 하므로 치밀화와 결정립 성장을 촉진시킨다.Cr 2 O 3 or MgO used as a sintering accelerator in the present invention is sintered by uranium vacancy while being dissolved in the UO 2 lattice during sintering, or Cr 2 O 3 and SiO 2 or MgO and SiO 2 form a new complex oxide Fast mass transfer promotes densification and grain growth.
따라서 매우 적은 양의 소결촉진제를 사용하더라도 소결밀도를 높이는 탁월한 효과가 있다.Therefore, even using a very small amount of sintering accelerator has an excellent effect of increasing the sintering density.
소결촉진제의 조성범위를 상기와 같이 한정한 이유는 ASTM UO2소결체 기술시방서에서 허용하는 한계 이하로 소결촉진제를 첨가하기 위함이다.The reason for limiting the composition range of the sintering accelerator as described above is to add the sintering accelerator below the limit allowed by the ASTM UO 2 sintered body technical specification.
상기 성형체를 환원성 분위기에서 소결하는 이유는 핵연료 소결체의 금속 대 산소(O/M)비를 2.0으로 맞추기 위함이며, 1600~1800℃ 온도범위에서 1시간 이상 소결하는 이유는 소결체의 밀도를 기술시방서에서 요구하는 93.5~96.5%를 맞추기 위해서이다.The reason for sintering the molded body in a reducing atmosphere is to adjust the metal-to-oxygen (O / M) ratio of the nuclear fuel sintered body to 2.0, and the reason for sintering for more than 1 hour at a temperature range of 1600 to 1800 ° C is because To meet the demand of 93.5 to 96.5%.
본 발명에서 제공하는 방법에 따라서 제조한 (U,Gd)O2핵연료 소결체의 밀도는 기술시방서에서 요구하는 93.5∼96.5% 범위에 있으나 소결촉진제를 첨가하지 않은 경우에는 밀도가 낮아서 기술시방서를 만족하지 못한다.The density of the (U, Gd) O 2 fuel sintered body manufactured according to the method provided by the present invention is in the range of 93.5 to 96.5% required by the technical specification, but when the sintering accelerator is not added, the density is low to satisfy the technical specification. can not do it.
또한 소결 촉진제를 사용하지 않으면 결정립 크기가 4㎛ 이지만 소결촉진제를 사용하면 6㎛ 이상을 얻는다.In addition, when the sintering accelerator is not used, the grain size is 4 µm, but when the sintering accelerator is used, 6 µm or more is obtained.
소결촉진제가 없이 UO2와 Gd2O3의 혼합분말을 압축성형 하여 성형체를 제조한 후, 성형체를 환원성 기체분위기에서 가열하면, 약 800℃부터 치밀화가 시작되고 온도가 높아지면 치밀화가 점점 빨라진다. 그러나 1300℃∼1600℃ 온도 범위에서는 치밀화가 지연되고 결국 (U,Gd)O2소결체의 밀도가 낮아지게 된다. 이것은 UO2와 Gd2O3가 고용체를 형성하면서 치밀화를 늦추기 때문인 것으로 알려져 있다.After forming a compact by compression molding a mixed powder of UO 2 and Gd 2 O 3 without a sintering accelerator, when the compact is heated in a reducing gas atmosphere, densification starts at about 800 ° C. and densification becomes faster as the temperature increases. However, in the temperature range of 1300 ° C to 1600 ° C, densification is delayed and the density of the (U, Gd) O 2 sintered compact is lowered. This is known because UO 2 and Gd 2 O 3 slow the densification while forming solid solutions.
반면 소결촉진제를 첨가한 UO2와 Gd2O3의 혼합분말을 성형ㆍ소결하면, 1300℃∼1600℃ 온도 범위에서도 치밀화가 지연되지 않고 빠르게 진행되어 최종적으로 고밀도를 갖는 (U,Gd)O2소결체를 제조할 수 있다.On the other hand, if molding and sintering a mixture powder of UO 2 with the addition of sintering promoting agent Gd 2 O 3, it proceeds rapidly without densifying the delay in the temperature range 1300 ℃ ~1600 ℃ finally having a high density (U, Gd) 2 O A sintered compact can be manufactured.
본 발명에서 제공하는 (U,Gd)O2핵연료 소결체의 제조방법은 유사한 핵연료 제조방법에 적용된다.The method for producing a (U, Gd) O 2 fuel sintered body provided in the present invention is applied to a similar fuel production method.
예를 들어, UO2와 동일한 격자 구조를 갖는 이산화플라토늄(PuO2)이 함유된 (U,Pu,Gd)O2핵연료 소결체 제조에도 사용되며, 그리고 어비움산화물(Er2O3)은Gd2O3와 같이 희토류계 산화물이고 동일한 결정구조(입방정)를 가지며 동시에 UO2기지(matrix)에서 유사한 소결거동을 보이므로 (U,Er)O2핵연료 소결체 제조에 사용된다. 따라서 (U,Gd)O2, (U,Pu,Gd)O2, (U,Er)O2, (U,Pu,Er)O2핵연료 소결체가 본 발명에 따라서 제조될 수 있지만 실시예에서는 (U,Gd)O2소결체에 관련해서 특징을 설명한다.For example, it is also used for the production of (U, Pu, Gd) O 2 fuel sintered bodies containing platinum (PuO 2 ) having the same lattice structure as UO 2, and arsenium oxide (Er 2 O 3 ) is Gd It is used in the manufacture of (U, Er) O 2 fuel sintered bodies because it is a rare earth oxide like 2 O 3 , has the same crystal structure (cubic crystal), and shows similar sintering behavior in the UO 2 matrix. Thus, (U, Gd) O 2 , (U, Pu, Gd) O 2 , (U, Er) O 2 , (U, Pu, Er) O 2 nuclear fuel sinters can be prepared according to the present invention, Features will be described in relation to the (U, Gd) O 2 sintered body.
「실시예 1]Example 1
AUC 공정으로 제조된 UO2분말에 Gd2O3분말을 중량비로 6% 함유한 출발분말에 소결촉진제로 0.02 중량% Cr2O3+0.01 중량% SiO2, 0.02 중량% Cr2O3+0.02 중량%SiO2, 0.02 중량% Cr2O3+0.03 중량% SiO2및0.02 중량% Cr2O3+0.04 중량% SiO2를 첨가하여 텀블링 믹서(tumbling mixer)에서 2시간 동안 혼합한다. 성형 모울드(mold) 벽에 스테아린산 아연(zinc stearate)을 도포한 다음, 혼합된 분말을 성형 모울드에 넣고 3 ton/cm2압력으로 성형한다. 성형 밀도는 5.7 g/cm2이다. 이 성형체를 환원성 기체분위기에서 시간당 300℃로 가열하여 700℃에서 1시간 유지한 후 다시 동일한 승온 속도로 1730℃까지 가열하고 4시간 동안 유지함으로써 소결한다. 소결기체에서 수증기/수소 기체비는 1.0×10-2, 2.0×10-2및 4.0×10-2이다. 상기 방법으로 제조한 소결체의 밀도는 아르키메데스 원리를 이용한 부력법으로 측정하고, 결정립 크기는 직선 교차법으로 측정한다.0.02% by weight Cr 2 O 3 + 0.01% by weight SiO 2 , 0.02% by weight Cr 2 O 3 +0.02 as a sintering accelerator in the starting powder containing 6% of Gd 2 O 3 powder in UO 2 powder prepared by AUC process Weight% SiO 2 , 0.02 weight% Cr 2 O 3 +0.03 weight% SiO 2 and 0.02 weight% Cr 2 O 3 +0.04 weight% SiO 2 is added and mixed for 2 hours in a tumbling mixer. Zinc stearate is applied to the molding mold wall, and then the mixed powder is placed in the molding mold and molded at 3 ton / cm 2 pressure. Molding density is 5.7 g / cm 2 . The molded body is heated to 300 ° C. per hour in a reducing gas atmosphere, maintained at 700 ° C. for 1 hour, and then sintered by heating to 1730 ° C. and maintained for 4 hours at the same heating rate. The water vapor / hydrogen gas ratio in the sinter gas is 1.0 × 10 −2 , 2.0 × 10 −2, and 4.0 × 10 −2 . The density of the sintered compact manufactured by the above method is measured by the buoyancy method using the Archimedes principle, and the grain size is measured by the linear crossing method.
실시예에서 얻은 (U,Gd)O2핵연료 소결체의 밀도 및 결정립 크기를 표 1과 표 2에 나타낸다. 본 발명의 효과를 분명하게 예시하기 위하여 소결촉진제를 첨가하지 않은 경우와 소결촉진제로 Cr2O3을 0.02 및 0.1 중량% 첨가하여 얻은 밀도 및 결정립 크기도 비교예로 나타낸다.The density and grain size of the (U, Gd) O 2 fuel sintered body obtained in the examples are shown in Table 1 and Table 2. In order to clearly illustrate the effect of the present invention, the density and grain size obtained by adding 0.02 and 0.1 wt% of Cr 2 O 3 with the sintering accelerator and the sintering accelerator are also shown as comparative examples.
표 1. 실시예 1에 따라서 제조한 소결체의 밀도 (이론 밀도의 백분율; %TD)Table 1. Density of Sintered Body Prepared According to Example 1 (Percentage of Theoretical Density;% TD)
표 2. 실시 예 1에 따라서 제조한 소결체의 결정립 크기(㎛) Table 2. Grain Size (µm) of the Sintered Body Prepared According to Example 1
[실시예 2]Example 2
실시예 1과 동일한 UO2및 Gd2O3분말을 사용하며, 동일한 방법으로 두 분말을 혼합한다. 여기에 소결촉진제로 0.02 중량% MgO+0.02 중량% SiO2를 첨가하여 실시 예 1과 동일한 방법으로 다시 혼합한다. 성형 및 소결은 실시 예 1과 같다.The same UO 2 and Gd 2 O 3 powders as in Example 1 are used and the two powders are mixed in the same manner. To this, 0.02% by weight MgO + 0.02% by weight SiO 2 was added as a sintering accelerator and mixed again in the same manner as in Example 1. Molding and sintering are the same as in Example 1.
실시예 2에서 얻은 (U,Gd)O2핵연료 소결체의 밀도 및 결정립 크기를 표 3과 표 4에 나타낸다. 소결촉진제를 첨가하지 않은 경우에 얻은 소결밀도 및 결정립 크기를 비교 예로 나타낸다.The density and grain size of the (U, Gd) O 2 fuel sintered body obtained in Example 2 are shown in Tables 3 and 4. The sintered density and grain size obtained when no sintering accelerator is added are shown as comparative examples.
표 3. 실시예 2에 따라서 제조한 소결체의 소결밀도 (%TD)Table 3. Sintered Density (% TD) of Sintered Body Prepared According to Example 2
표 4. 실시예 2에 따라서 제조한 소결체의 결정립 크기 (㎛)Table 4. Grain Size of the Sintered Body Prepared According to Example 2 (µm)
상기와 같은 본 발명은 UO2분말과 Gd2O3분말의 혼합분말에 소결촉진제로서 크롬산화물과 실리콘산화물 (Cr2O3+SiO2)을 함께 첨가하고, 또는 마그네슘산화물과 실리콘산화물(MgO+SiO2)을 함께 첨가하여 고밀도와 큰 결정립을 동시에 갖는 (U,Gd)O2핵연료 소결체를 제조하는 방법을 제공함으로써, 종래 기술에서는 고밀도 소결체를 제조하기 위하여 필요하던 분말분쇄 공정을 생략할 수 있어서 제조비용을 절감할 수 있고, 동시에 소결체의 결정립을 크게 함으로써 핵연료의 안전성이 향상되는 효과가 있다.In the present invention as described above, chromium oxide and silicon oxide (Cr 2 O 3 + SiO 2 ) are added together as a sintering accelerator to the mixed powder of UO 2 powder and Gd 2 O 3 powder, or magnesium oxide and silicon oxide (MgO + By adding together SiO 2 ) to provide a method for producing a (U, Gd) O 2 fuel sintered body having both high density and large grains simultaneously, the powder grinding process required for manufacturing the high density sintered body can be omitted. The manufacturing cost can be reduced, and at the same time, the grain size of the sintered body is increased, thereby improving the safety of the nuclear fuel.
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Citations (4)
| Publication number | Priority date | Publication date | Assignee | Title |
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| US4869868A (en) * | 1987-11-23 | 1989-09-26 | General Electric Company | Nuclear fuel |
| JPH05264769A (en) * | 1992-01-13 | 1993-10-12 | Westinghouse Electric Corp <We> | Method for cladding fuel pellet |
| JPH06300877A (en) * | 1993-04-15 | 1994-10-28 | Toshiba Corp | Nuclear fuel element |
| KR960705324A (en) * | 1993-09-22 | 1996-10-09 | Nuclear fuel sintered body and its manufacturing method (NUCLEAR FUEL SINTERED BODY AND PROCESS FOR PRODUCING IT) |
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| US4869868A (en) * | 1987-11-23 | 1989-09-26 | General Electric Company | Nuclear fuel |
| JPH05264769A (en) * | 1992-01-13 | 1993-10-12 | Westinghouse Electric Corp <We> | Method for cladding fuel pellet |
| JPH06300877A (en) * | 1993-04-15 | 1994-10-28 | Toshiba Corp | Nuclear fuel element |
| KR960705324A (en) * | 1993-09-22 | 1996-10-09 | Nuclear fuel sintered body and its manufacturing method (NUCLEAR FUEL SINTERED BODY AND PROCESS FOR PRODUCING IT) |
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