It is very important that the confinement of a spent fuel storage systems is maintained because if the confinement is damaged, the gaseous radioactive material inside the storage cask can leak out and have a radiological impact on the surrounding public. For this reason, leakage rate tests using helium are required for certificate of compliance (CoC) and fabrication inspections of spent fuel storage cask. For transport cask, the allowable leakage rate can be calculated according to the standardized scenario presented by the IAEA. However, for storage cask, the allowable leakage rate is determined by the canister, facility, and site specific information, so it is difficult to establish a standardized leakage rate criterion. Therefore, this study aims to establish a system that can derive system-specific leakage test criteria that can be used for leakage test of actual storage systems. First, the variables that can affect the allowable leakage rate for normal and accident conditions were derived. Unlike transportation systems, for storage systems, the dose from the shielding analysis and the dose from the confinement analysis are summed up to determine whether the dose standard is satisfied, and even the dose from the existing nuclear facilities is summed up during normal operation condition. For this reason, the target dose is used as an input variable when calculating the allowable leakage rate for the storage system. In addition, the main variables are the distance from the boundary of the exclusive area, the number of cask, the inventory of nuclide material in the cask, the free volume, and the internal and external pressure. Utilizing domestic and US NRC guidelines, we derived basic recommended values for the selected variables. The GASPARII computer code that can evaluate the dose to the public under normal operating conditions was utilized. Using the above variables, the allowable leakage rate is calculated and converted to the allowable criteria for helium leakage rate test. The developed system was used to calculate the allowable leakage rate for normal and accident conditions for a hypothetical storage system. The leakage rate criteria calculation system developed in this study can be useful for CoC and fabrication inspections of storage systems in the future, and a GUI-based program will be built for user convenience.

Since the time to consider when evaluating leakage of spent fuel dry storage systems is very long, assumptions that continue to leak at the initial leakage rate are too conservative. Therefore, this study developed a dynamic methodology to calculate the change in leakage rate using time-varying variables and apply it to calculate the amount of radioactive leakage during the evaluation period. The developed dynamic methodology was then applied to calculate the leakage radiation source term for a hypothetical dry storage system and used to perform a public dose assessment. When applying the developed dynamic leakage rate evaluation methodology for more accurate confinement evaluation in case of containment damage of dry storage system, it was found that the change of leak rate with time is very insignificant if the hole diameter is small enough, and the leak rate decreases rapidly with time when a hole with a certain diameter or larger occurs. In the case of the accident condition, except when the hole is very large, it corresponds to the chocked flow condition, and the leak rate decreases rapidly as soon as the internal pressure is sufficiently lowered to enter the molecular and continuum flow region. In the case of a small hole diameter, the leakage volume is very small, so even if the dynamic methodology is applied, the evaluation results are not different from the case where the initial leakage rate continues, and when the hole diameter exceeds a certain value, the internal pressure drops according to the leakage volume, and the leakage rate decreases significantly. As a result of evaluating the dose to residents by applying the calculated radiation source term, it was confirmed that the dose criteria was exceeded when a hole with a diameter of about 4 μm occurred under off-normal conditions, and the dose standard was exceeded under accident conditions when a chocked flow occurred between the diameter of the hole and 2-3 μm, resulting in a rapid increase in the dose. The results of this study are expected to contribute to a more accurate evaluation of the confinement performance of storage systems, which will contribute to the design of optimal dry storage systems.

Chitosan, natural organic polymer, has been applied in water treatment as adsorbent due to non-toxic for human being. The amino group as functional group, can interacts with cation and anion at the same time. The prepared chitosan bead (HCB) was crosslinked to increase chemical stability (HCB-G) and both HCB and HCB-G were prepared to increase physical strength by drying referred to DCB and DCB-G, respectively. The adsorption effect for crosslinking and drying for four types of chitosan bead was tested using pseudo fist order (PFO), pseudo second order (PSO), and intraparticle diffusion model (ID). Regardless of PFO and PSO, the order of K, rate constant, is as followed: HCB > HCB-G > DCB > DCB-G for Cu(II) and phosphate. Drying leading to contraction of bead significantly reduced adsorption rate due to reduce the porosity of chitosan. In addition, crosslingking also negatively effect on adsorption rate. When compared with Cu(II) using hydrogel bead, phosphate showed higher value than Cu(II) for PFO and PSO. The application of ID showed that both hydrogel beads (HCB and HCB-G) obtained a very low R2 ranging to 0.37 to 0.81, while R2 can be obtained to over 0.9 for DCB and DCB-G, indicting ID is appropriate for low adsorption rate.

본 연구는 콩 콤바인 수확 시 수확장애와 종실의 품위를 떨어뜨리는 잎과 줄기의 노화 지연에 관한 연구로 2015~2016년도 국립식량과학원 남부작물부(경남 밀양시 소재)의 시험포장에서 수행하였다. 시험품종은 대원콩과 풍산나물콩을 사용하였으며, 6월 9일에 고휴 2열로 휴폭 110 cm, 주간거리 40 cm, 1주 2본 재배하였고, 콩 꼬투리를 0~50%범위에 수준별로 제거하여 성숙기 생육특성과 잎과 줄기의 건물중에 대해서 조사하였다. 주요결과를 요약하면 다음과 같다. 1. 대원콩과 풍산나물콩 모두 종실비대시 콩 꼬투리 제거가 생육특성에 영향을 미치지는 않았지만, 제거 비율이 높아질수록 성숙기가 지연되었다. 2. 콩 꼬투리 제거 비율이 높아짐에 따라 종실 무게도 증가하였는데 꼬투리의 제거비율이 대원콩은 20%, 풍산나물콩은 30% 이상일 경우에는 차이가 없었다. 3. 꼬투리 제거비율이 높아질수록 잎과 줄기의 건물중이 증가하였는데, 이는 종자에 축적되어야 할 잉여 동화 산물이 잎과 줄기에 축적된 결과로 보여진다. 4. Sink/source 감소폭은 대원콩 20% 제거 시 0.18, 풍산나물콩 30% 제거 시 0.42로 이전 처리구에 비해 크게 감소하였기 때문에 잎과 줄기의 성숙이 불리할 것으로 판단된다.

This study was carried out to determine the effects of application levels of fertilizer and sowing methods on yields and nutritive values of Italian ryegrass (IRG) in early spring. Five fertilizer levels were used: Treatment 1, 100-80-80 kg/ha; Treatment 2, 120-100-100 kg/ha; Treatment 3, 140-120-120 kg/ha; Treatment 4, 160-140-140 kg/ha; Treatment 5, 140-120-120 kg/ha of N-P2O5-K2O with silicate fertilizer 200 kg/ha. Dry matter (DM) yield was 8,330 kg/ha in Treatment 5, 7,686 kg/ha in Treatment 4, and 7,347 kg/ha in Treatment 3. There was no significant difference in total digestible nutrients (TDN) content. The content of crude protein was the highest in Treatment 5. Dry matter ratio was the lowest in Treatment 5. In Treatment 3, DM yield was 7,347 kg/ha, when total amounts of fertilizers were applied at one time. However, DM yield was 7,405 kg/ha, when 50% of pre-planting fertilizer and 50% of supplementary fertilizer were applied at different time. There was no significant difference between total application and split application of fertilizers. However, DM yield was 9,469 kg/ha in application treatment with 100 kg/ha of additional urea at three to four leaf stages of IRG. Regarding DM yield by sowing methods of IRG, the following order was found: drill seeding (8,176 kg/ha) > rotary-broadcast seeding-stamping (7,957 kg/ha) > rotary-broadcast seeding (7,810 kg/ha) > broadcast seeding (7,347 kg/ha) > broadcast seeding-rotary (7,034 kg/ha). DM yield (59.57%) was the lowest in broadcast seedingrotary. Crude protein content was the highest with rotary work but the lowest with broadcast seeding.

본 연구는 한약재 (결명자, 계피, 산초, 감초) 추출물의 반추위내 발효와 미생물 활성에 대한 효과를 구명하기 위하여 수행되었다. In vitro 건물소화율은 계피와 산초 추출물 첨가구에서는 0시간대, 감초 추출물 첨가구에서는 3시간대에 대조구에 비해 현저히 (P<0.05) 낮았다. 한약재 추출물 첨가에 따른 발효 시간대별 휘발성 지방산 조성의 변화는 3시간대에서만 처리간 유의성이 인정되었는데, acetate 비율은 대조구가 천연 추출물 첨가구보다 유의적으로 높았으나, butyrate, isobutyrate, isovalerate 및 valerate은 대조구에서 가장 낮았다 (P<0.05). 미생물 성장율은 발효 3시간대에서 결명자 첨가구를 제외한 한약재 첨가구에서 대조구에 비해 유의적(P<0.05)으로높았으나다른발효시간대에서는차이가없었다 이상의 결과로부터 한약재로 사용되고 있는 계피, 산초 및 감초 추출물을 in vitro 반추위 배양액에 첨가하였을 때, 발효초기에 반추위 미생물의 활성을 억제하는 경향은 있었으나 미생물 성장에 대한 억제 효과는 없는 것으로 나타났다.

The effects of seeding rate and N fertilizer on leaf area index, dry matter accumulation, grain yield and yield components in oats were studied using split experimental design. The results indicated t㏊t seeding rate and N fertilizer ㏊d significant influence on leaf area index, dry matter accumulation and grain yield. With the increasing seeding and fertilizer rates, leaf area index, aboveground dry matter increased significantly. Oat reached the highest grain yield under 112.5㎏/h㎡ seeding rate, N2 was the best N fertilizer treatment for oat.

Ordinary concrete uses aggregate sufficiently soaked with water, and is weighed, mixed with other materials and placed in accord with performances required in the construction field. Recently special concrete with high fluidity and durability is required but it is difficult to use top-quality concrete due to lack of high-quality aggregate, delayed transportation because of traffic jam, etc. In addition, sometimes the use of a remicon is inevitable just for small-sized concrete constructions or it is difficult for a remicon to reach remote construction places such as mountainous areas. To solve these problems, this study attempted to pack concrete materials. In other words, it is to instantize concrete. This study dried aggregate, a material of concrete, and compared the change of absorption phase of the aggregate in water and in paste in order to examine the effect of the dryness of aggregate on its absorption rate and, based on the absorption rate, decided water addition ratio necessary for the reduction of unit quantity caused by the use of dry aggregate in designing concrete mixture, and analyzed the properties of unhardened concrete according to water addition ratio in manufacturing concrete using aggregate in the state of absolute dryness and in the state of surface dryness.

A field experiment was carried out to determine the effects of mechanical and chemical drying agents at mowing on the field drying rate and hay quality of orchardgrass dominant pasture plants. The mower conditioner /chemical drying agent ( 2% conditioning

This experiment was canied out to study the effect of cutting frequencies (3, 4 and 5 cuts per year) and mineral nitrogen fertilization on dry matter yields, in order to estimate optimum level of fertilizing mineral nitrogen in orchardgrass(Dacry1is glome

To examine the effects of light intensity on photosynthesis, corn and sorghum species were grown under shade cloths, which reduced light intensity by 25,50 and 75%. Photosynthetic rates were measured between 10 a.m. to noon on a clear day in early and mid

본 시험은 사초용(飼草用) 호밀의 파종기와 파종량이 사초(飼草)의 생육특성, 월동성 및 수량에 미치는 영향을 구명(究明)하기 위하여 서울대(大) 농대(農大) 사초시험포장(飼草試驗圃場)에서 수행되었다. 본 시험에서 호밀의 파종기(播種期)를 9월 8일, 9월28일, 10월18일로 하고 ha당 파종량(播種量)을 80, 130 및 180kg로 하여 9처리(處理) 3반복(反復) 난괴법으로 실시하였다. 호밀의 초장(草長)은 파종기(播種期)에 의하여 영향을 받지 않