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.

Weight loss that influences quality and farmer incomes is affected by the storage environment of agricultural products. The interior of storage should be maintained at high humidity to prevent the weight loss of products which contain a lot of moisture. The research had constantly proceeded with change in the heat exchanger surface areas, humidity systems, and weight loss forecast to maintain high humidity within storage. Relative humidity that exerts an effect weight loss of crop is influenced by storage temperature, leak state, and volume of product. When weight loss is predicted, different conditions of these factors are derived. In case of CA storage, ways of forecasting the weight loss become easier compared to cold storage due to sealed storage with external environment during storage period. In this study, apples were stored in purge-type CA storage and weight loss has been predicted by using operating characteristics and environmental conditions. As a result, humidity variation in the storage fluctuates with the operation of the unit-cooler. Furthermore, unit-cooler operation factor is influenced by outside temperature and respiration heat. Prediction value of weight loss according to temperature and humidity has been most accurately predicted. Prediction value through defrosting water measured shows unit-cooler work quality. K-value needs verification to calculate the VPD method.

본 연구에서는 토마토를 일정한 기간(15일) 동안 저장하여 토마토의 품질인자인 감모율, 색상과 경도를 분석하고 비 파괴적 방법으로 토마토 경도를 측정한 결과로 경도와 감모율 사이의 상관관계를 분석하고 선형회귀모델을 도출하여 토마토 품질을 예측하고자 하였다. 그린하우스에서 재배된 ‘티와이250’품종을 수확한 후 일반 과실 종이 박스에 포장한 후 설정환경이 10℃, 90%RH인 항온항습챔버에 저장하여 3일 간격으로 경도, 무게와 색상 변화를 조사하였다. 15일간 저장 중 감모율은 저장기간이 증가함에 따라 증가하나 1.1% 정도에 머물러 단순히 감모율 인자로만 판단했을 때 토마토의 신선도 품질에 영향 끼치는 수준은 아니다. 색상변화 중 명도와 색조 각은 저장기간의 증가에 따라 감소하는 경향을, a/b와 ΔE는 증가하는 경향을 나타냈었고 일원분산분석결과를 볼 때 유의한 수준이었다(p<0.001). 경도는 저장기간이 증가함에 따라 감소하는 경향을 나타냈으며 저장 15일차에는 경도감소율이 40% 이상인 것으로 나타났다. 그리고 비 파괴방법으로 측정한 경도 값과 감모율 사이의 상관관계를 분석하여 선형회귀모델 WL=-0.0241×F+1.5213을 하였으며 모델의 추정치 오차는 ±0.231이었다. 이러한 결과에 비추어볼 때 수확 후 일정한 저장환경에서 비파괴적인 경도 측정을 통해 감모율을 추정하고 신선도를 판단하는 지표고 사용하는 것이 가능한 것으로 판단되었다.