The stabilization techniques are highly required for damaged nuclear fuel to strengthen safety in terms of transportation, storage, and disposal. This technique includes recovering fuel materials from spent fuel, fabrication of stabilized pellets, and fabrication of fuel rods. Thus, it is important to identify the leaching behavior of the stabilized pellets to verify their stability in humid environments which are similar to storage conditions. In this study, we introduce various leaching experiment methods to evaluate the leaching behavior of the stabilized pellets, and determine the most suitable leaching test methods for the pellets. Also, we establish the leaching test conditions with various factors that can affect the dissolution and leaching behavior of the stabilized pellets. Accordingly, we prepare the simulated high- (55 GWd/tU) and low- (35 GWd/tU) burnup nuclear fuel (SIMFUEL) and pure UO2 pellets sintered at 1,550°C and 1,700°C, respectively. Each pellet is placed in a vessel and filled with DI water and perform the leaching test at three different temperature to verify the leaching mechanism at different temperature range. Based on the standard leaching test method (ASTM C1308-21), the test solution is removed from the pellet after specific time intervals and replaced in the fresh water, and the vessel is placed back into the controlled-temperature ovens. The test solutions are analyzed by using ICP-MS.

We developed leaching kinetics models and a convective mass transfer model for water soluble solid in jujube (Zizyphus jujube) fruits with hot water. Hot-water leaching process was conducted at 90°C for 100 min. The ratio of solvent (volume, mL) to solid (mass, g) was set to varied ratios of 1:6, 1:8, 1:10, and 1:12.5. The mass transfer coefficients (k) were determined based on the 1st- and 2nd-order kinetic models. The amount of solvent influenced the extraction rate and yield. A higher extraction rate and a higher yield were obtained from a lower solvent to solute ratio (1:6, 1:8, 1:10) compared to high ratio (1:12.5). This implies that an appropriate amount of solvent (i.e., water) is necessary to conduct the extraction process of jujube fruit.

One of the trace constituents included in cement clinker, chromium, has become prominent and highly noticed lately as a social issue both inside and outside of this country because it affects the human body negatively. The purpose of the present study was to investigate leaching properties of water-soluble hexavalent chromium by different manufacturing conditions of cement clinker. Raw materials were prepared to add different SiO2, Al2O3 and Fe2O3 sources. After the raw materials, such as limestone, sand and clay, iron ore was pulverized and mixed, and the raw meal was burnt at 1450˚C in a furnace with an oxidizing atmosphere. Leaching of soluble hexavalent chromium showed a tendency to decrease with an increasing LSF and IM. However, leaching of soluble hexavalent chromium increased with an increasing S.M. Alkali contents of iron source minerals is closely related to the leaching properties of soluble hexavalent chromium. Green sludge has the highest content of alkali added; leaching of water-soluble hexavalent chromium was mostly high. In order to reduce the water-soluble hexavalent chromium in cement, reducing the alkali content in raw materials is important.

Since it was developed by Joseph Aspdin, cement has been a common construction materials up to the present time.However, there are trace constituents in cement clinker. One of the trace constituents included in cement clinker, chromium,has become prominent and highly noticed lately as a social issue both inside and outside of this country because it affects thehuman body negatively. The aim of the present study was to investigate the concentration of water-soluble hexavalent chromiumin cement clinker by using industrial by-products. For that reason, raw materials were prepared to add different SiO2 , Al2O3,and Fe2O3 sources. After the raw materials such as the limestone, the sand and the clay, iron ore was pulverized and mixed,and the raw meal was burnt at about 1450oC in a furnace with an oxidizing atmosphere. The part in the raw materials of theclinker was substituted with slag, sludge, etc. and this was used to manufacturing cement clinker. To investigate the water-soluble hexavalent chromium content in clinker, raw meal was prepared by changing the modulus, the type, and the contentof clinker materials and tested concentrations of hexavalent chromium in the clinkers. To determine Cr+6 formation of theclinker, tests were done with raw meals adding chromium by using different industrial by-products. Consequently because thechromium was to be included in the raw materials of the clinker, production of Portland cement clinker was included with thechromium. Also, the chromium was converted into hexavalent chromium in the burning process.

본 연구는 옥수수 재배지에서 경운방법과 가축분뇨의 시용이 사료용 옥수수의 생산성 및 질소의 용탈에 미치는 영향을 알아보기 위하여 국립축산과학원 초지사료과 시험포장(천안)에서 lysimeter를 이용하여 2008년 4월부터 8월까지 실시하였다. 시험구 배치는 분할구배치법으로 경운방법(경운과 무경운)을 주구로 하였으며, 가축분뇨의 종류(화학비료, 우분퇴비 및 돈분퇴비)를 세구로 하였다. 가축분뇨의 시용은 화학비료구는 표준시용량(N-)으로 200, 150 및

This experiment was conducted to determine the effects of applying level of pig slurry on the characteristics of runoff and leaching water in lysimeter. Treatments were broken down into five treatments such as non-chemical fertilizer, chemical fertilizer (200㎏ N/㏊) and pig slurry (200, 400, 600㎏ N/㏊), and 3-time-repeated randomized complete block design was fulfilled. The concentrations of NO₃-N was raised(p＜0.05) in proportion to the applying level of pig slurry. NO₃-N concentration of leaching water collected from soil depth 20㎝ and 40㎝ was intensified as the applying level of pig slurry was higher (p＜0.05) in pig slurry 600㎏ N/㏊ application. In conclusion, pig slurry at the volcanic ash soil in Jeju area can replace the chemical fertilizer as it is tested that applying 200㎏ N/㏊ of pig slurry and chemical fertilizer show the same productivity of sorghum×sudangrass hybrid. But more than 200㎏ N/㏊ of pig slurry may not be appropriate because it may contaminate the runoff and leaching water even though it may increase for the forage productivity.

This study was carried out to investigate the effects of cattle slurry application in paddy land cultivated with whole crop rice on the properties of soil and water. A field study was conducted at Baeksan-myeon, Kimje, Jeonbuk province in Korea on clay loam soil for 3 years. All plots were arranged in completely randomized design with three replicates. The contents of organic and inorganic properties in soil samples collected at the end of the experiment were remarkably higher than those at the beginning of the experiment (P＜0.05). The concentrations of NO₃-N, NH₃-N and PO₄-P in discharge and leaching water were different significantly between both treatments.

This study was carried out to investigate the properties of soil and water under Double-cropping SSH followed by whole crop barley (SSFWB) or by Hairy vetch (SSFHV) in paddy land. A field study was conducted at Baeksan-myeon, Kimje, Jeonbuk province in Korea on clay loam soil for 3 years. All plots were arranged in completely randomized design with three replicates. The pH and the contents of T-N and organic matter (OM) in soil samples collected at the end of the experiment were remarkably higher t㏊n those at the beginning of the experiment in both SSFWB and SSFHV treatment (P＜0.05). The contents of an exchangeable cations at the end of the experiment were remarkably higher t㏊n those at the beginning of the experiment in both SSFWB and SSFHV (P＜0.05). And then, the concentration of NO₃-N, NH₃-N and PO₄-P in discharge and leaching water were not influenced by the cropping system

This study are carried out to investigate the effects of double cropping system, such as winter whole crop barley followed by rice (WBFR) or after Sorghum × Sudan hybrid (WBASS), in paddy land on the properties of soil and water. A field study was conducted at Baeksan-myeon, Kimje, Jeonbuk province in Korea on clay loam soil for 3 years. All plots were arranged in completely randomized design with three replicates. The pH and the contents of T-N, P₂O? and organic matter (OM) in soil samples collected at the end of the experiment were remarkably higher t㏊n those at the beginning of the experiment (P＜0.05) in both WBFR and WBASS. The contents of an exchangeable cations (CEC) at the end of the experiment were remarkably higher t㏊n those at the beginning of the experiment (P＜0.05). The concentrations of NO₃-N, NH₃-N and PO₄-P in discharge and leaching water were not influenced by the cropping system.

본 연구에서는 돈분뇨의 처리형태가 초지의 생산성, 토양의 지력증진 효과 및 양분의 용탈량을 조사하여 친환경적 조사료를 생산하기 위하여 전라북도 축산 진흥연구소내의 초지시험포의 영년초지에서 2002년 10월부터 2005년 10월까지 3개년에 걸쳐 수행하였다. 시험구는 돈분뇨의 처리형태별로 화학비료 표준구, 돈분액비 100%+N 50%구 및 돈분퇴비 100%+N 50%구로 배치하여 수행하였다. 돈분액비 및 돈분퇴비의 시용에 따른 건물수량은 화학비료 시용구와

저 농도와 고 농도 돈분 액비의 비료효과를 비교하기 위해 제주대학교 목장에서 2005년 6월부터 9월까지 피의 생산성, 피 재배 토양의 화학적 특성 및 용탈수 특성을 조사하였다. 실험은 난괴법 4처리 (무비구, 200 N kg/ha +150Pkg/ha+150 K kg/ha 화학비료구, 200 N kg/ha 1.8% DM 저농도 돈액비구, 200 N kg/ha DM 7.0% 고농도 돈액비구) 4반복으로 실시하였다. 용탈수는 2005년 8월 21일(1차),

본 연구는 acid bake-water leaching system (AWS)를 이용하여 Au 정광으로부터 경제적이고 친환경적인 유용금속 용출을 위하여 황산염 용매제의 적용성을 파악하는 것이다. AWS 실험은 전기로를 이용하여 다양한 baking 온도(100℃~500℃)와 황산염 용매제(H2SO4, K2SO4, (NH4)2SO4, MgSO4, CaSO4) 조건에서 수행하였다. Baking 온도가 400℃까지 증가할수록 유용금속의 용출률은 증가하였다. 용출시간에 따른 AWS 실험결과, 최대 용출률 조건은 (NH4)2SO4 용매제이었다. 본 연구를 통하여 (NH4)2SO4 용 매제가 AWS를 이용한 유용금속 용출에 있어 효과적인 용매제로 사용가능함을 입증하였다.

In this lysimeter experiment, temporal changes of water percolation rate, irrigation requirement and No3 －-N leaching were investigated under different cultural practices that were no-till direct seeding on flooded paddy (NTDSF), till direct seeding on flooded paddy (TDSF), and transplanting. The highest water percolation rate of 3,001 l/m2 was measured in NTDSF. Others were 2,551 l/m2 and 2,210 l/m2 in TDSF and transplanting. Water percolation rate in NTDSF and TDSF was increased by 36% and 15% compared to transplanting. Water percolation rates in all cultural practices were increased remarkably from the reproductive growth stage and relatively large amount of water loss through percolation was measured even after the reproductive growth stage. A total irrigation requirement was 3,469 l/m2 in NTDSF and 2,898 l/m2 in TDSF. That was equivalent to 45% and 21 % of increase compared to 2,389 l/m2 in transplanting. The largest No3 －-N leaching through the entire rice growing period was 701 mg/m2 in NTDSF and was followed by 494 mg/m2 in TDSF and 465 mg/m2 in transplanting. The ratios to the total amount of No3 －-N leaching at the vegetative growth stage, reproductive growth stage and ripening stage were 31 %, 41 % and 28% in NTDSF; 21 %, 48% and 31 % in TDSF; and 18%, 48% and 35 % in transplanting.