• Proceedings of the Korea Concrete Institute Conference
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• 2004.11a
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• pp.381-384
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• 2004

Delaying and objection for the construction of storage spent-fuel disposal has prompted to consider expanding on-site storage of spent reactor fuel since it can eliminate the need for costly and difficult shipping and control of the spent fuel completely under the direction of the owner-utility. The dry storage unit developed in Canada can accommodate Korea heavy water reactor fuel elements and become a candidate for the Korean market. In this paper, finite element analyses were carried out in order to investigate the structural behavior of the nuclear spent fuel dry storage system, which is subjected to impact loads such as collision of a truck load and dropping of flask under the irregular operation.

• Journal of Nuclear Fuel Cycle and Waste Technology(JNFCWT)
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• v.10 no.2
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• pp.105-115
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• 2012

Necessity of demonstration test to evaluate the structural integrity of a basket for accident conditions arose during license approval procedure for the WSPP's dry storage facility named MACSTOR/KN-400. A drop test facility for demonstration was constructed in KAERI site and demonstration tests for basket drop were conducted. As the upper welding region of a loaded basket was collided with a dropped basket during the drop test, the welding in this region was fractured and leakage happened after the drop test. The enhancement of basket design was needed since the existing basket design was not able to satisfy the performance requirement. The directions for design modification were determined and six enhanced designs were derived based on these directions. Structural analyses and specimen tests for each enhanced design were conducted. By evaluating structural analysis results and test results, one among six enhanced designs was decided as a final design for revision. The final design was the one to reduce the height of central post of a basket and to decrease the impact velocity with a dropped basket. Test basket models were fabricated with accordance with the final enhanced design. Additional demonstration test was performed for this test model and all the performance requirements were satisfied.

• Journal of Nuclear Fuel Cycle and Waste Technology(JNFCWT)
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• v.9 no.2
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• pp.93-98
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• 2011

Saline corrosion is one of the major degradation mechanisms for stainless steel type 304 (SS304) dry storage cask during the spent fuel interim storage period. Slow strain rate test (SSRT) and neutral salt spray test (NSS) were performed at $85^{\circ}C$ and $200^{\circ}C$ with 0.5 wt% sodium chloride mist sprayed on the cold-rolled SS304 specimens of different degrees of reduction in this study. The weight changes of the NSS specimens tested at $85^{\circ}C$ for 2000 hours differed greatly from those at $200^{\circ}C$. The weight loss of NSS specimens was not significant at $85^{\circ}C$ but the weight gain decreased gradually with increasing the cold-rolled reduction. The yield strength (YS) and ultimate tensile stress (UTS) values obtained from the SSRT tests for lightly cold-rolled specimens in the salt spray environment at $85^{\circ}C$ and $200^{\circ}C$ are slightly lower than in air. But for those with 20% reductions, the specimen strengths were no longer changed by the saline corrosion. The preliminary results demonstrated that the quality and performance of cold-rolled SS304 is acceptable for fabrication of dry storage casks. However, more work on the corrosion behavior of cold-rolled stainless steel in the saline atmosphere is needed to better understand its long-term performance.

• Journal of the Korean Society of Food Science and Nutrition
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• v.19 no.6
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• pp.617-624
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• 1990

Proper processing condition of Yukwa(oil popped rice snack) for mass production and pop-ping mechanism of it were tested with Shinsun (waxy, Japonica type rice) which was excellent for Yukwa making. Optimum steaming time of dough was 15 min among 4 to 60 min and reasonable moisture content of the dough before steaming was 4895 among 48 to 53% which had good and fine texture. Acceptable stirring time of steamed dough was not significantly different among 1 to 4 min, but no stirring with much larger volume was shown very poor and too soft in texture. At the simplification test of milling method, wet milling was better then dry milling in expansion rate and high temperature treatment of dough at 6$0^{\circ}C$ gave negative effect on their quality. Extending high temperature treatment of dough, reducing sugars in the dough increased and it might be caused of starch degradation. In addition of some other protein sources to dough, Yukwa quality were in proportion to the protein content of the beans. At the long term storage of the Yukwa base, moisture absorption was different depending upon RH of atmosphere and the quality of Yukwa was inferior by storage time. By addition of some alcoholic beverage, such as Makkoli, Soju and Chungju, expansion rate and their texture were somewhat improved by increasing addition amount of them from 15% to. 30％ on dough (w/w).

• Journal of the Korean Society of Food Science and Nutrition
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• v.34 no.5
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• pp.721-728
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• 2005

The physicochemical and microbial characteristics of pickled cucumber prepared with dry salting method, which has been used for industry, were investigated. Salting and storage conditions were HSHT $(30\%,\;25^{\circ}C)$, MSMT $(21\%,\;15^{\circ}C)$, MSLT $(21\%,\;0^{\circ}C)$, LSMT $(15\%,\;15^{\circ}C)$ and LSLT $(15\%,\;0^{\circ}C)$. Acidity was lower, and pH was higher in higher salt concentration as well as lower temperature groups. At the storage of 165 days, acidity and pH reached to $0.21\%$ and 4, respectively in MSLT and HSHT, of which conditions fermentation was retarded, compared to the other groups. During storage of pickled cucumber, greenness (-a) of Hunter color system showed the highest in MSLT ranged from -10.70 to -8.08, while in LSMT, the lowest to 1.17. Total microbial and lactic acid bacteria number in HTST and MSLT were the lowest than in other groups, while tile highest in LSMT. Yeast was not detected in HSHT and MSLT after 36 days of storage, while higher in LSMT Texture profile analysis exhibited that fracturability (2,318 g and 2,318 g) and hardness (849 g and 702 g) were highest in HSHT and MSLT, compared to the other groups. Scores of over-all preference for MSLT and LSLT were higher with 8.8 and 7.6, respectively, compared to the other products (p<0.05). Based on these results, lower saltiness and lower storage temperature condition was better for pickled cucumber preparation in industry.

• 한국신재생에너지학회:학술대회논문집
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• 2010.06a
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• pp.110.2-110.2
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• 2010

현재 상용가능한 연소전 $CO_2$ 포집 기술은 습식 스크러빙 방식으로 고온의 합성가스를 상온 수준으로 온도를 낮춘 후 $CO_2$를 포집해야 하고 포집된 $CO_2$의 압력이 낮아 재압축하여 저장소로 보내야 함에 따라 큰 폭의 열효율 손실이 불가피하다. 고온 고압에서 이산화탄소를 포집할수 있는 고체 흡수제를 이용할 경우 이산화탄소 포집 치 저장 추가에 따른 시스템 효율 저하를 최소화할 수 있다. 고체 $CO_2$ 흡수제는 서로 연결된 두 개의 유동층 반응기를 순환하면서 흡수탑에서는 합성가스 중의 $CO_2$를 흡수하고 재생탑에서는 고온의 수증기와 접촉하여 흡수된 $CO_2$를 다시 배출함으로써 재생된다. 따라서 건식 재생 $CO_2$ 흡수제는 유동층 공정에 응용가능한 물성과 함께 높은 $CO_2$ 흡수능과 빠른 반응성이 요구된다. 본 연구에서는 유동층 공정에 적합한 물성을 가진 연소전 $CO_2$ 포집용 고체 흡수제를 분무건조법으로 제조하였으며, 모사 합성가스를 이용하여 열중량분석기와 기포유동층반응기를 이용하여 $200^{\circ}C$ 흡수, $400^{\circ}C$ 재생, 압력 20 bar 조건으로 반응성을 측정하였다. 개발된 고체 $CO_2$ 흡수제는 열중량분석기에서는 반응 후 10-13 wt%의 무게증가를 나타내었고 기포유동층반응기에서는 8-10 wt%의 $CO_2$ 흡수능을 보여주었다. 특히 수증기의 함량이 10% 이상에서 높은 흡수능을 나타내어 수증기가 반응에 크게 작용하고 있음을 알 수 있었다.

• Proceedings of the Plant Resources Society of Korea Conference
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• 2019.04a
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• pp.91-91
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• 2019

전북 완주군 농가에서 2017년 12월에 재배한 '시베리아'와 '메두사' 품종을 1시간 이내에 국립원예특작과학원 실험실로 이동하였다. 알약(SmartFreshTM, AgroFresh Inc., USA)형태의 1-MCP를 1.875g/3.55m3 기준으로 정량하여 Activator Kit(SmartFreshTM, AgroFresh Inc., USA)에 넣어 마개를 닫고 몇 번 흔들어주어 녹인 후 1.5 ppm이 되도록 처리하였으며 3시간 훈증 후 30분 환기하였다. 훈증처리 후 절화 백합은 유공 필름 슬리브를 이용하여 포장한 후 골판지상자에 넣어 모의 수출환경에서 수송방식은 건식(건조처리)상태로 $4^{\circ}C$ 저장고에 암상태로 저장하면서 무처리를 대조로 에틸렌 노출 조건 조성을 위하여 후레쉬라이프(탑프레쉬) 5g 봉지를 상자내부 5개, 상자외부 저장고 내에 10개로 총 15개의 에틸렌 발생제 처리를 하였다. 백합 절화 신선도 유지기간 연장을 위한 선도유지제 전처리 효과는 1.5 ppm 1-MCP 3시간 훈증처리에 의해 잎의 황화현상을 지연시키는 효과가 있었다. 전체적으로 판정한 절화수명은 '시베리아'는 무처리 9.0일, 1-MCP 훈증 9.0일, 에틸렌 발생제 8.3일, 1-MCP 훈증+에틸렌 발생제 9.5일이었으며 '메두사'는 무처리 6.5일, 1-MCP 훈증 7.5일, 에틸렌 발생제 5.7일, 1-MCP 훈증+에틸렌 발생제 8.5일로 나타났다. 에틸렌에 노출은 꽃의 빠른 노화를 야기하여 절화수명을 단축 시켰으며 이상개화를 보이는 꽃도 있어 상품성이 크게 떨어졌다. 1-MCP에 의해 잎의 황화 억제에 효과적이었으며 저장 중 에틸렌 발생제를 동시에 처리하였을 때 품질유지 효과가 더 크게 나타났으며 '메두사' 품종에서는 만개시 화색도 더 진하게 나타났다. 따라서, 저온저장이나 선적시 에틸렌 발생이 많은 품목과 혼합하게 될 것이 예상될 경우에 품질유지를 위해 1-MCP 훈증처리를 하면 효과적일 것으로 사료된다.

• Proceedings of the Korean Vacuum Society Conference
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• 2011.08a
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• pp.301-301
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• 2011

최근 고밀도 메모리 반도체의 재료와 빠른 응답을 요구하는 나노입자를 이용한 비휘발성 메모리 소자의 제작에 대한 연구가 활발히 진행되고 있다. 그에 따른 기존의 플래쉬 메모리가 가지는 문제점을 개선하기 위해서 균일하고 규칙적으로 분포하는 새로운 나노소재의 개발과 비휘발성, 고속 동작, 고집적도, 저전력 소자의 공정기술이 요구되고 있다. 또한 부유게이트에 축적되는 저장되는 전하량을 증가시키기 위한 새로운 소자구조 개발이 필요하다. 한편, 실리 사이드 계열의 나노입자는 금속 나노입자와 달리 현 실리콘 기반의 반도체 공정에서 장점을 가지고 있다. 따라서 본 연구에서는 화합물 중에서 비휘발성 메모리 장치의 전기적 특성을 향상 시킬 수 있는 실리사이드 계열의 바나듐 실리사이드(V3Si) 박막을 열처리 과정을 통하여 수 nm 크기의 나노입자로 제작하였다. 소자의 제작은 p-Si기판에 실리콘산화막 터널층(5 nm 두께)을 건식 산화법으로 성장 후, 바나듐 실리사이드 금속박막을 RF 마그네트론 스퍼터 시스템을 이용하여 4~6 nm 두께로 터널 베리어 위에 증착하고, 그 위에 초고진공 마그네트론 스퍼터링을 이용하여 SiO2 컨트롤 산화막층 (20 nm)을 형성시켰다. 여기서 V3Si 나노입자 형성을 위해 급속 열처리법으로 질소 분위기에서 800$^{\circ}C$로 5초 동안 열처리하여 하였으며, 마지막으로 열 기화 시스템을 통하여 알루미늄 전극(직경 200 ${\mu}m$, 두께 200 nm)을 증착하여 소자를 제작하였다. 제작된 구조는 금속 산화막 반도체구조를 가지는 나노 부유게이트 커패시터이며, 제작된 시편은 투사전자현미경을 이용하여 나노입자의 크기와 균일성을 확인했다. 소자의 전기적인 측정을 E4980A capacitor parameter analyzer와 Agilent 81104A pulse pattern generator system을 이용한 전기용량-전압 측정을 통해 전하저장 효과 및 메모리 동작 특성들을 분석하고, 열처리 조건에 따라 형성되는 V3Si 의 조성을 엑스선 광전자 분광법을 이용하여 확인하였다.

• Journal of the Korean Society for Nondestructive Testing
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• v.19 no.2
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• pp.93-99
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• 1999

SCAI(spent CANDU fuel bundle serial number identifier) was developed to read serial numbers of spent fuel bundles in the spent fuel storage. For the purpose of effectively identifying the serial number of fuel bundle. SCAI was composed of underwater camera & light part. guiding & supporting part and control & monitor part. So it is easy to assemble and disassemble, and operate. It was tested to read serial numbers of spent fuel bundles loaded in basket during the recent spent fuel transfer campaign at Wolsong Unit 1. And it was also applied to read serial numbers of spent fuel bundles discharging from the initial core at Wolsong Unit 3 by slight change of camera and light. Inspectors could easily operate SCAI after several practices in the storage pond, which was a user friendly. And SCAI provided clear and immediate picture for identification of serial numbers of spent fuel bundles. It was interally evaluated that SCAI greatly contributed to cut inspection efforts for national and international safeguards at Wolsong power plant.

• Journal of Nuclear Fuel Cycle and Waste Technology(JNFCWT)
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• v.14 no.4
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• pp.411-422
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• 2016

Recently, because the wet pool storage facilities of NPPs in Korea has become saturated, there has been much active R&D on an interim dry storage system using a transportation and storage cask. Generally, the shielding evaluation for the design of a spent fuel transportation and storage cask is performed by the design basis fuel, which selects the most conservative fuel among the fuels to be loaded into the cask. However, the loading of actual spent fuel into the transportation metal cask is not limited to the design basis fuel used in the shielding evaluation; the loading feasibility of actual spent fuel is determined by the shielding evaluation that considers the characteristics of the initial enrichment, the maximum burnup and the minimum cooling period. This study describes a shielding analysis method for determining the minimum cooling period of spent fuel that meets the domestic transportation standard of the dual purpose metal cask. In particular, the spent fuel of 3.0~4.5wt% initial enrichment, which has a large amount of release, was evaluated by segmented shielding calculations for efficient improvement of the results. The shielding evaluation revealed that about 81% of generated spent fuel from the domestic nuclear power plants until 2008 could be transported by the dual purpose metal cask. The results of this study will be helpful in establishing a technical basis for developing operating procedures for transportation of the dual purpose metal cask.