Earticle

In order to determine the relationship between water content and flower qualities of oriental hybrid lily cv. ‘Siberia’ cut flower, flowers were subjected to dry and cold storage at 5oC for 3, 6, and 12 days and subsequently exposed to ambient temperature (26oC) in bottles with water for up to 16 days. Flowers stored at 22oC in dry condition for 3 days were used as the control. Changes in fresh weight, moisture content, water balance, flowering stages, osmolality and vase life of cut flowers were observed. Flowers treated with cold and dry storage had higher moisture content compared to control sample. However, this trend was evident only for 3-day cold and dry stored sample during the whole storage period. The fresh weight of cut flowers increased gradually when the samples were transferred to ambient temperature in water bottles and then declined steadily before reaching the peak in between 6-8 days of vase life. However, the changes of fresh weight of control sample were substantially faster than samples pre-treated with cold and dry storage. This was also correlated with the water balance of cut flower as it reached the minus (-) value in 6-8 days of vase life at ambient temperature. Cut lily flowers showed high osmolality values corresponding with the duration of dry storage regardless of low or higher temperature. However, osmolality had no effect on vase life since flower stem absorbed water rapidly at the end of dry storage period. Our vase life results suggest that cold and dry storage of lily cut flowers for a certain period could ensure longer vase life at ambient temperature. It was observed that prolonging the storage period at cold and dry condition for more than a week significantly increased bud abortion, reduced longevity of flowers and reduced the vase life of cut flowers. On the other hand, the shorter cold and dry storage treatment delayed the bud opening and senescence of the flowers, thus, slowering the normal maturation and aging. Results indicated that dry and cold storage at 5oC for 3 days was effective in maintaining and preserving overall quality and vase life at ambient condition of oriental hybrid lily cut flowers.

The objective of this study was to investigate changes in drying yield, pH, water activity, microbial growth, and storage stability of bottom rounds of Hanwoo beef under four different dry-aging treatments (T1–T4) as temperature (2~4℃), relative humidity (65~86%) and dry-aging period (20~90 d). The drying yield decreased by 83.13–97.05% as the drying period increased. Among the four treatments, there were no significant differences in drying yield after 60 d of dry-aging. The total plate aerobic counts (TPC) increased by 1.07–4.39 log colony-forming units (CFU)/g as the dry-aging period increased. Of the four treatments, T4 at 40, 60, and 90 d had significantly higher TPCs than those observed for the other treatments on the same days (p<0.05). As the period of dry-aging increased, pH values increased by 5.35– 5.88 for knuckle and 5.34–5.62 for sirloin muscle, and water activity values decreased. For knuckle and sirloin muscle, the water activity values at 40 d and 60 d of T1 and T4 were significantly higher than those of the other treatments on the same days (p<0.05). The thiobarbituric reactive substances and volatile basic nitrogen values of the aged products increased as the dry-aging period increased. The results of this study showed that dry-aging conditions such as those in the T2 or T3 treatments (with a gradual increase in temperature and humidity) for less than 60 d would be best for yield, reduction of microbial growth and storage stability by dry the muscle surface quickly at the beginning period. Further research should include meat quality and economic analysis for these conditions that examines the benefits of these dry-aged products for the end processor.

한국원자력환경공단에서는 국내 경수로 원전에서 발생된 사용후핵연료를 건식으로 저장할 수 있는 콘크리트 용기를 개발하 였다. 본 저장용기는 사용후핵연료가 건식환경에서 장기간 저장되는 동안 용기 및 사용후핵연료의 건전성이 유지되며, 방사 선량률이 저장시설의 설계기준을 초과하지 않도록 설계되어야 한다. 특히, 저장시설은 정상 및 사고조건에서 적절한 방사선 방호를 위한 차폐설계가 이루어져야 한다. 이를 위해 본 연구에서는 미국 10CFR72 및 10CFR20의 기술기준과 NRC의 표준 심사지침 NUREG-1536에서 제시한 평가방법에 따라 건식저장조건하에서 단일 콘크리트용기 및 2×10 용기배열조건의 선 량율을 평가하였다. 평가결과, 일반인에 대한 연간선량 한도인 0.25 mSv를 만족하는 통제구역 경계까지의 거리는 약 230 m 로 도출되었다. 콘크리트 저장용기의 설계사고는 2×10 배열의 저장시설에서 한 개의 저장용기가 이송 중 전도사고가 발생 하여 용기의 바닥면이 통제구역 경계로 향하는 상황으로 가정하였다. 전도된 저장용기의 바닥면으로 부터 100 m 및 230 m 지점에서 각각 12.81 mSv 및 1.28 mSv로 평가되었다. 본 연구를 통해 건식저장조건에서 콘크리트 저장용기 및 저장시설은 적절하게 평가된 통제구역경계까지의 거리가 확보된다면 방사선적 안전성이 유지됨을 확인할 수 있었다. 본 평가결과만으 로 건식환경의 저장용기(시설) 설계에 직접 적용하기는 어렵겠으나, 향후‘국가 고준위폐기물 관리 전략’에 근거한 원전내 저장시설 또는 중간저장 시설의 설계 및 운영에 유용한 자료가 될 것으로 사료된다.

The Korea Radioactive Waste Agency (KORAD) has developed a concrete cask for the dry storage of spent nuclear fuel that has been generated by domestic light-water reactors. During long-term storage of spent nuclear fuel in concrete casks kept in dry conditions, the integrity of the concrete cask and spent nuclear fuel must be maintained. In addition, the radiation dose rate must not exceed the storage facility’s design standards. A suitable shielding design for radiation protection must be in place for the dry storage facilities of spent nuclear fuel under normal and accident conditions. Evaluation results show that the appropriate distance to the annual dose rate of 0.25 mSv for ordinary citizens is approximately 230 m. For a 2×10 arrangement within storage facilities, rollover accidents are assumed to have occurred while transferring one additional storage cask, with the bottom of the cask facing the controlled area boundary. The dose rates of 12.81 and 1.28 mSv were calculated at 100 m and 230 m from the outermost cask in the 2×10 arrangement. Therefore, a spent nuclear fuel concrete cask and storage facilities maintain radiological safety if the distance to the appropriately assessed controlled area boundary is ensured. In the future, the results of this study will be useful for the design and operation of nuclear power plant on-site storage or intermediate storage facilities based on the spent fuel management strategy.

Currently, the interim storage pools of spent fuels in South Korea are expected to become saturated from 2024. It is required to prepare an operation plan of a domestic dry storage facility during a long-term period, with the researches on safety evaluation methods. This study modified the FRAPCON code to predict the spent fuel integrity evaluation such as the axial cladding temperature, the hoop stress and hydrogen distribution in dry storage. The cladding temperature in dry storage was calculated using the COBRA-SFS code with the burnup information which was calculated using the FRAPCON code. The hoop stress was calculated using the ideal gas equation with spent fuel information such as rod internal pressure. Numerical analysis method was used to calculate the degree of hydrogen diffusion according to the hydrogen concentration and temperature distribution during a dry storage period. Before 50 years of dry storage, the cladding temperature and hoop stress decreased rapidly. However, after 50 years, they decreased gradually and the cladding temperature was below 400 K. The initial temperature distribution and hydrogen concentration showed a parabolic line, but hydrogen was transferred by the hydrogen concentration and temperature gradient over time.

오리엔탈 나리 '시베리아'의 건식저장 기간에 따른 절화 보존 시 수분함량 변화와 절화수명을 구명하고자 하였다. 본 실험에서 저장 기간에 따라 저온 저장($5^{\circ}C$)을 한 다음 절화수명에 관계된 수분 및 품질 변화와 개화 정도를 검토하여 '시베리아' 나리의 절화 수확 후 관리 기술에 관계된 기본적인 자료를 얻고자 하였다. '시베리아' 나리를 채화하여 저온에서 건식저장 기간에 따라 3일, 6일, 12일한 후 절화보존 동안에 생체중 변화, 수분균형, 개화정도 등을 조사하였으며 대조구로서 상온 건식저장과 비교하였다. 저온 건식저장 후에 '시베리아' 나리의 수분함량은 건식저장 기간에 영향을 받아 저장하는 기간이 짧을수록 높아져 저장 3일이 다른 처리구보다 높아지는 경향을 보였다. 꽃의 수분함량은 절화보존 시 지속적으로 증가하는데, 저장 기간이 짧을수록 수분이 높게 유지되었다. 생체중 변화는 건식저장 기간에 영향을 받아 저장 기간이 짧았던 것에서 생체중의 증가 정도가 컸으며 음(-)의 값에 이르는 기간이 늦어지는 것으로 나타났다. 또한 절화보존 시 생체중 변화는 저온 건식저장 3일이 생체중 증가 정도가 완만하게 변하며 수분균형도 8일째에 음(-)의 값에 도달하는 것으로 나타났다. 그러나 저장 온도 차이에 따른 생체중 변화는 상온에서 저장한 절화가 저온저장보다 증감 정도가 더 빠른 것으로 나타났다. 개화정도는 '시베리아' 나리의 건식저장 기간이 길어질수록 개화시기가 빨라지며, 절화가 빨리 시들어 상품으로써 유지 기간이 짧아졌다. 개화상태를 비교해 보면 3일 저온 건식저장이 다른 처리보다 개화하는 속도가 늦었으나 절화수명은 다른 처리구보다 길게 나타났다. '시베리아' 나리의 저온 건식저장은 저장 기간이 짧을수록 저장 후 수분함량이 높고 수분 균형값이 음(-)에 늦게 도달하였으며 개화상태가 좋고 절화수명도 길어지는 것으로 나타났다. '시베리아' 나리는 건식저장을 통한 작물체내 수분 함량 감소가 절화보존 시 개화 특성에도 영향을 미쳐 저장기간이 길수록 절화수명이 감소하여 상품 가치를 떨어뜨렸다. '시베리아' 나리 절화를 소비자가 이용 시, 상품 가치 유지를 위해서는 기존 결과의 6일 동안 저온 건식저장도 절화수명을 단축시키므로 저장 기간을 최소화하는 것이 절화 품질 유지를 위해 바람직하다고 판단된다.

In order to determine the relationship between water content and flower qualities of oriental hybrid lily cv. 'Siberia' cut flower, flowers were subjected to dry and cold storage at $5^{\circ}C$ for 3, 6, and 12 days and subsequently exposed to ambient temperature ($26^{\circ}C$) in bottles with water for up to 16 days. Flowers stored at $22^{\circ}C$ in dry condition for 3 days were used as the control. Changes in fresh weight, moisture content, water balance, flowering stages, osmolality and vase life of cut flowers were observed. Flowers treated with cold and dry storage had higher moisture content compared to control sample. However, this trend was evident only for 3-day cold and dry stored sample during the whole storage period. The fresh weight of cut flowers increased gradually when the samples were transferred to ambient temperature in water bottles and then declined steadily before reaching the peak in between 6-8 days of vase life. However, the changes of fresh weight of control sample were substantially faster than samples pre-treated with cold and dry storage. This was also correlated with the water balance of cut flower as it reached the minus (-) value in 6-8 days of vase life at ambient temperature. Cut lily flowers showed high osmolality values corresponding with the duration of dry storage regardless of low or higher temperature. However, osmolality had no effect on vase life since flower stem absorbed water rapidly at the end of dry storage period. Our vase life results suggest that cold and dry storage of lily cut flowers for a certain period could ensure longer vase life at ambient temperature. It was observed that prolonging the storage period at cold and dry condition for more than a week significantly increased bud abortion, reduced longevity of flowers and reduced the vase life of cut flowers. On the other hand, the shorter cold and dry storage treatment delayed the bud opening and senescence of the flowers, thus, slowering the normal maturation and aging. Results indicated that dry and cold storage at $5^{\circ}C$ for 3 days was effective in maintaining and preserving overall quality and vase life at ambient condition of oriental hybrid lily cut flowers.