For Korean nuclear fuel cycle project, it is necessary to design and evaluate the integrity of spent fuel storage. For the design and evaluation of spent fuel storage, it is necessary to evaluate the properties of various materials used in spent fuel storage. The materials previously considered in the design of nuclear power plants were limited to static properties and were listed in design and manufacturing code and standards. However, for the evaluation of the storage containers in scenarios such as transportation and events, dynamic material property evaluations are required. Research on the dynamic properties of materials is generally conducted in the fields of automotive and aerospace, and most of the studies are on metal materials under sheet conditions. Since the structural materials of the storage containers for used nuclear fuel are mostly composed of thick materials, consideration should be given to property evaluation methodology and quantitative comparison. In this study, the mechanical properties of stainless steel material with canister application were evaluated according to the strain rate, and the crack resistance evaluation was also performed. It was confirmed the changes in strength and crack resistance according to the increase in strain rate and observed differences in microstructural hardening behavior.

지구온난화에 대한 현사시나무의 적응반응을 구명하기 위해서, CO2농도 및 기온 상승된 조건에서 80 일간 생장한 현사시나무 삽목묘의 수분생리특성을 조사하였다. 대조구는 기온이 주간 22℃, 야간 17℃ 이고, CO2농도는 주간 380ppm, 야간 400ppm이다. CO2농도 및 기온을 상승시킨 처리구는 기온이 주 간 27℃, 야간 22℃이고, CO2농도는 주간 770ppm, 야간 790ppm이다. 처리구는 잎이 전개된 개수, 개 엽의 평균면적, 전체 엽면적이 대조구에 비해서 낮은 값을 나타냈다. 그리고 처리구는 대조구에 비하여 지상부의 건중량이 적고, 지하부의 건중량이 많았으며, 지하부에 대한 바이오매스의 분배율이 높았다. 이러한 결과로 CO2농도 및 기온이 상승되면 수분을 필요로 하는 동화기관의 면적이 감소되고, 수분을 흡수하는 지하부에 대한 바이오매스 분배율이 높아짐을 확인할 수 있었다. 또한 처리구는 광도 및 CO2 농도의 변화에 상관없이 기공전도도와 증산속도가 대조구에 비하여 낮게 유지되고 광합성에 대한 수분 이용효율이 대조구보다 높게 나타냈다. 이 결과를 통하여 동화기관의 수분손실 억제반응과 수분이용효 율이 증대반응을 확인할 수 있었다. 그리고 처리구는 절단한 잎이 건조공기에 노출되어도 상대함수율이 대조구에 비하여 천천히 감소하는 경향을 나타내 동화기관의 수분손실 억제반응이 재확인되었다.

수변완충림으로 조성된 4년생 포플러 5수종들에 대하여 바이오매스 및 적응능력을 조사하였다. 포플러들의 생존율은 평균 85.7%로 나타났고, 미루나무 교잡종 Dorskamp클론이 91.6%로 가장 우수하였다. 포플러 수종별 지상부 바이오매스는 미루나무 교잡종 97-19클론이 54.6 ton/ha으로 가장 높게 나타났으며, 수원포플러 Suwon클론은 17.7 ton/ha으로 다른 클론들에 비해 저조하게 나타났다. 식엽충에 의한 잎 피해는 미루나무 교잡종 97-19클론이 4.7로 나타나 가장 피해가 적었으며, 수원포플러 Suwon클론이 3.4로 피해가 가장 큰 것으로 나타났다. 생존율, 지상부 바이오매스, 수세 및 피해조사 등의 특성을 이용하여 산출한 포플러 수종별 수변지에 대한 적응능력은 미루나무 교잡종 97-19클론이 가장 높게 나타났으며, 그 다음으로 Dorskamp클론이 높게 나타났다. 따라서, 미루나무 교잡종 97-19 및 Dorskamp클론이 수변완충림 조성에 적합한 포플러 수종으로 판단된다.

This study was conducted to figure out the differences in physiological responses, e.g. growth, photosynthetic activity and water potential, and photoinhibition tolerance in photosystem between superior and inferior families of Pinus densiflora under drought condition. Superior which is KW85 and inferior which is KW40 families were selected using progeny test results of height growth. In 2007, seeds were collected from seed orchard. In 2008, seedlings were produced and cultivated, and from April 2009 drought treatment was started with shading treatment and plants were harvested in Sept. 2009. There was no significant difference in height growth between families. In case of leaf water potential, KW85 showed higher water potential under drought condition. But there was no significant difference in drought with shading treatment. There was no difference in photosynthetic rate but stomatal conductance and transpiration rate of KW85 showed lower value than KW40. So water use efficiency of KW85 showed higher value in every treatment. Non-photochemical quenching of KW40 showed higher value in drought treatment, but there was no significant difference in control and drought with shading treatment. Xanthophyll cycle pool size of KW85 showed higher value in drought treatment, but in drought with shading treatment KW40 showed higher value. Selected superior family showed higher drought tolerance according to water use efficiency, and it also has effective non-photochemical quenching ability. In contrast inferior family respond more sensitively in photoinhibition under drought condition.

We conducted this study to compare physiological response according to growing conditions between superior and inferior family of Pinus densiflora. In 1981, open-pollinated (OP) progenies of P. densiflora were planted in Chuncheon (CC) and Naju (NJ). We selected KW2 as a superior family and KW23 as a inferior family based on volume index among 30 OP progenies. We calculated general combining ability of each 30 OP progenies in each sites, and compared family growth rank. We collected needles of selected families in CC and NJ, and analyzed chlorophyll content, nitrated reductase (NR) activity, nitrogen content, and superoxide dismutase (SOD) acitivity. In CC, chlorophyll content and nitrogen content were more in needles of KW2 than those of KW23. In NJ, KW2 showed higher NR activity than KW23, and according to site, families in CC showed higher NR activity than those in NJ. SOD activities of both families were higher in NJ, and KW23 showed higher activity than KW2 in both sites. Consequently, inconsistency of the growth performance of two families was caused by different genetic and physiological responses.

We tested the hypothesis that alpine plants have special physiological and biochemical mechanisms in addition to their structural adaptation in order to survive under extreme conditions. The photosynthetic organs of Pinus pumila were used to examine the seasonal changes in sugar concentration, antioxidative enzyme, and lipid peroxidation. The concentrations of sucrose, glucose, fructose and reducing sugar were the highest in the leaves in April. But sugar contents in buds and inner barks did not respond sensitively on temperature change. Meanwhile superoxide dismutase (SOD) activity responded sensitively on the change of temperature and SOD in all tissues maintained high activity in April. Meanwhile anthocyanin content increased rapidly in June but the increase of anthocyanin content was not enough to prevent their tissues from the damage by the exposure of high temperature or other stress. In conclusion, under low temperature condition, P. pumila increased the concentration of soluble sugars and SOD activity in their tissues in order to overcome extreme environmental condition. But in summer, these stress defense system against high temperature might be disturbed slightly. This results in the increase of malondialdehyde (MDA) contents in three tissues by lipid peroxidation.