• 대한금속재료학회지
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• 제48권5호
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• pp.410-416
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• 2010

Studies were carried out to establish the technology for sodium-clad compatibility and to analyze the compatibility behavior of the Sodium-cooled Fast Reactor (SFR) cladding material under a flowing sodium environment. The natural circulation facility caused by the thermal convection of the liquid sodium was constructed and the 316-series stainless steels were exposed at $650{^{\circ}C}$ liquid sodium for 1458 hours. The weight change and related microstructural change were analyzed. The results showed that the quasi-dynamic facility represented by the natural convection exhibited similar results compared to the conventional dynamic facility. Selective leaching and local depletion of the chromium, re-distribution of the carbide, and the decarburization process took place in the 316-series stainless steel under a flowing sodium environment. This process decreased as the sodium flowed along the channel, which was caused by the change in the dissolved oxygen and carbon activity in the liquid sodium.

• 한국건축시공학회:학술대회논문집
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• 한국건축시공학회 2011년도 추계 학술논문 발표대회
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• pp.201-203
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• 2011

The purpose of this study was to develop and evaluate of fire resistive cladding systems for HSC(high-strength concrete) column, which was mainly constructed with aerogel blanket insulation material. The aerogel blanket-fire protective gypsum board cladding system showed that it clearly secure the fire resistance performance of HSC column when the reinforcing measures had achieved for four cross-sectional edge sides of structure and the system is well continued during the test period with no significant deformation or separation etc. It was checked out the 20mm thickness cladding system consist with AG(5mm)+FGB(15mm) can secure 3hour-fire resistance performance adequately.

• Nuclear Engineering and Technology
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• 제42권3호
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• pp.249-258
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• 2010

Recently, many utilities have considered interim dry storage of spent nuclear fuel as an option for increasing spent fuel storage capacity. Foreign nuclear regulatory committees have provided some regulatory and licensing requirements for relatively low- and medium-burned spent fuel with respect to the prevention of spent fuel degradation during transportation and interim dry storage. In the present study, the effect of cladding creep and hydride distribution on spent fuel degradation is reviewed and performance tests with high-burned Zircaloy-4 and advanced Zr alloy spent fuel are proposed to investigate the effect of burnup and cladding materials on the current regulatory and licensing requirements. Creep tests were also performed to investigate the effect of temperature and tensile hoop stress on hydride reorientation and subsequently to examine the temperature and stress limits against cladding material failure. It is found that the spent fuel failure is mainly caused by cladding creep rupture combined with mechanical strength degradation and hydride reorientation. Hydride reorientation from the circumferential to radial direction may reduce the critical stress intensity that accelerates radial crack propagation. The results of cladding creep tests at $400^{\circ}C$ and 130MPa hoop stress performed in this study indicate that hydride reorientation may occur between 2.6% to 7.0% strain in tube diameter with a hydrogen content range of 40-120ppm. Therefore, it is concluded that hydride re-orientation behaviour is strongly correlated with the cladding creep-induced strain, which varies as functions of temperature and stress acting on the cladding.

• Nuclear Engineering and Technology
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• 제54권7호
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• pp.2475-2490
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• 2022

The Accident Tolerant Fuel (ATF) is a new concept of fuel, which can not only withstand the consequences of the accident for a longer time, but also maintain or improve the performance under operating conditions. ISAA is a self-developed severe accident analysis code, which uses modular structures to simulate the development processes of severe accidents in nuclear plants. The basic version of ISAA is developed based on UO₂-Zr fuel. To study the potential safety gain of ATF cladding, an improved version of ISAA, referred to as ISAA-ATF, is introduced to analyze the station blackout accident of PWR using ATF cladding. The results show that ATF cladding enable the core to maintain a longer time compared to zirconium alloy cladding, thereby enhancing the accident mitigation capability. Meanwhile, the generation of hydrogen is significantly reduced and delayed, which proves that ATF can improve the safety characteristics of the nuclear reactor.

• 한국원자력학회:학술대회논문집
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• 한국원자력학회 2001년도 추계학술발표회요약집
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• pp.204-204
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• 2001

• Corrosion Science and Technology
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• 제2권6호
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• pp.253-259
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• 2003

Zirconium based alloys have been extensively used as a cladding material for fuel rods in nuclear reactors, due to their low thermal neutron absorption cross-section, excellent corrosion resistance and good mechanical properties at high temperatures. However, a cladding material for fuel rods in nuclear reactors was contact water during long time at high-temperature, so it is necessary to improve the wear and corrosion resistance of the fuel cladding, At ambient environment, there are few data or paper on the characteristic of corrosion in chloride solution and acidic solution. The specimens used in this work are pure Zr and Zircaloy-4. Zircaloy-4 is a specific zirconium-based alloy containing, on a weight percent basis, 1.4% Sn, 0.2% Fe, 0.1% Cr. Pitting corrosion resistance of two alloys by ASTM G48 is higher than that of electrochemical method. Passive film formed on Zircaloy-4 is mainly composed of $ZrO_2$, metallic Sn, and iron species regardless of formation environments. Also, passive film formed on Zr alloys shows n-type semiconductic property on the base of Mott-Schottky plot.

• Composites Research
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• 제29권1호
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• pp.40-44
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• 2016

원자력발전소에서 사용되고 있는 핵연료 피복관은 핵분열 생성물들의 외부 유출을 방지하기 위해 고온 고압의 냉각수 분위기에서 우수한 산화저항성을 가져야 한다. 그러나 후쿠시마 원전사고의 LOCA(Loss-Of-Coolant-Accident)와 같은 중대사고에서 핵연료의 피복관과 수증기 사이의 격렬한 반응으로 인해 급격한 고온산화를 동반한 다량의 수소발생으로 수소폭발을 방지하기 위한 핵연료의 개발이 요구되고 있다. 이에 따라 핵연료 피복관의 안전성 향상을 위해 내방사선성이 우수하며 높은 강도와 산화, 부식에 대한 내화학적 안정성 및 우수한 열전도도 의 특성을 갖는 SiC와 같은 구조용 세라믹스가 활발히 연구되고 있다. $SiC_f/SiC$ 복합체 보호막 금속 피복관은 지르코늄 피복관 튜브에 SiC 섬유를 필라멘트 와인딩 한 후 Polycarbosilane을 polymer로 함침하여 기지상을 형성하는 공정을 이용하였다. 따라서 이렇게 제조한 $SiC_f/SiC$ 복합체 금속 피복관을 Drop Tube Furnace를 이용한 열충격에 따른 시편의 산화 및 미세조직을 분석하였다.

• 한국소성가공학회:학술대회논문집
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• 한국소성가공학회 2007년도 춘계학술대회 논문집
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• pp.389-393
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• 2007

The most demanded bimetals in home appliances are manufactured by mainly cladding process and these are mainly consist of Cu alloy and Ni alloy. But it is very difficult to clad these alloys, because the brittle ${Cu_3}{O_4}$ oxide film formed easily on Cu alloy surface during cladding process. Clad rolling and heat treatment processes were applied for the development of bimetals by using the Ni alloy and the 3 types of Cu alloys. Optical microstructure was observed and micro-hardness, specific resistance, deflection were measured from the manufactured new bimetals specimens.

• 한국윤활학회:학술대회논문집
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• 한국윤활학회 2002년도 proceedings of the second asia international conference on tribology
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• pp.185-186
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• 2002

Fretting of fuel rod cladding material, Zircaloy-4 tube, in PWR nuclear power plants must be reduced and avoided. Nowadays the introduction of surface treatments or coatings is expected to be an ideal solution to fretting damage since fretting is closely related to wear. corrosion and fatigue. Therefore. in this study the fretting wear experiment was performed using TiAlN coated Zircaloy-4 tube as the fuel rod cladding and uncoated Zircaloy-4 as on of grids, especially concentrating on the sliding component. Fretting wear resistance of TiAlN coated Zircaloy-4 tubes was improved compared with that of TiN coated tubes and uncoated tubes and fretting wear mechanisms were brittle fracture and plastic flow at lower slip amplitude but severe oxidation and spallation of oxidative layer at higher ship amplitude.

• 한국전산구조공학회:학술대회논문집
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• 한국전산구조공학회 2005년도 춘계 학술발표회 논문집
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• pp.63-70
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• 2005

For using narrow site effectively, recently constructions of high-rise buildings have been increased. High-rise buildings are mainly governed by wind loads. Since wind flow Is vaned irregularly, the experimental method such as wind tunnel test is used to evaluate real wind loads. In this study, it is intended to estimate design wind pressure and amounts of material of cladding by AIK recommendations and wind tunnel test. Also, this study includes the investigation of reliability, suitability and economical efficiency in design of cladding of buildings by AIK recommendations and wind tunnel test by comparing and examining various results. Finally, it is concluded that not only AIK recommendations but also wind tunnel test should be considered to get the reasonable wind pressure acting on the cladding of high-rise buildings.