In nuclear fuel development research, consideration of the back-end cycle is essential. In particular, a review of an in-reactor performance of nuclear fuel related to the various degradation phenomena that can occur during spent fuel dry storage is an important area. The important factors affecting the degradation of zirconium-based cladding during dry storage are the cladding’s hydrogen concentration and rod internal pressure after irradiation. In this study, a preliminary analysis of the in-reactor behavior of the HANA cladding, which has been developed and is currently undergoing licensing review, was performed, and based on this result, a comparative analysis between nuclear fuel with HANA cladding and current commercial fuel under storage conditions was performed. The results show that the rod internal pressure of nuclear fuel with HANA cladding is not significantly different from that of commercial cladding, and the hydrogen concentration in the cladding tends to reduce due to the increased corrosion resistance, so fuel integrity in a dry storage conditions is not expected to be a major problem. Although the lack of cladding creep data under dry storage conditions, the results from the Halden research reactor test comparing in-reactor creep behavior with Zircaloy-4 showed that there is sufficient margin for degradation due to creep during storage.

As global warming and consumer’s preference for tropical/subtropical fruits increase, the number of orchards cultivating tropical/subtropical fruits in Korea is increasing. Accordingly, concerns about the introduction of exotic invasive pests that host tropical fruits. In this study, efficacy of ethyl formate(EF), as alternative to methyl bromide(MB), was evaluated. Commercial trial of EF was conducted in mango post-harvest storage conditions for controlling Scirtothrips dorsalis. Application of 10 g/m3 of EF for 4 hours at 10 ℃ showed proven efficacy on S. dorsalis without any phytotoxic damage on mango fruits in that condition.

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.

This study evaluated the Protaetia brevitarsis larvae powder’s characteristic changes using hot air drying (60±2.5oC, 12 h) with different pre-treatment methods, including two sacrifice methods, two storage temperatures, and two defatting processes. Appearance, yield, moisture contents, pH, color, proximate analysis, volatile basic nitrogen level, DPPH radical scavenging activity, and total phenol content were assessed. Results revealed that a combination of blanching, defatting, and -20oC storage temperature resulted in higher total phenol contents, lower water contents, and lower volatile basic nitrogen levels than other methods. Defatted treatment resulted in a higher L-value than the non-defatted treatment. Taken together, these results indicate that a combination of -20oC storage, blanching, and defatting is the optimal pre-treatment method for obtaining P. brevitarsis larvae powder with high total phenol content, low water content, and low volatile basic nitrogen, taking into account cost efficiency considerations.

In order to construct and operate the dry storage systems, it is essential to confirm the safety of the systems through safety analysis. If the dry storage cask is damaged due to an accident, a large amount of radioactive material may be leaked to the outside and cause radiation exposure to surrounding workers and nearby public, so the effect thereof should be evaluated. Many input parameter are required in the confinement evaluation for accident condition, and in this study, the change in the confinement evaluation result according to the change of major input parameter is to be studied. In this study, we selected fractions of radioactive materials available for release from spent fuel, cooling time, and distance to exclusive area boundary as the major input parameter. In general, the release fraction suggested by NUREG-1536 has been used, but NUREG-2224 provides the fraction for high burn-up spent fuel in fire and impact accident conditions, unlike NUREG-1536 which provide a single value. In the case of the distance to exclusive area boundary, 100 to 800 m was considered, and in the case of the cooling time, 10 to 50 years was considered in this study. In order to compare the dose change by the parameter, we set up the hypothetical storage system. A storage cask of the system contain 21 PWR spent fuel assemblies with an initial enrichment of 4.5wt%, burnup of 45,000 MWD/MTU. During the accident condition, it is assumed that the cask is leaked at 1.0×10−7cm3·sec−1. Since the main dose criterion for accident conditions is 50 mSv of effective dose, effective doses are calculated in this study. In an accident condition, transuranic particulate contribute most of the doses, so the doses are determined according to the fraction for the particulate. Therefore, it was confirmed that the dose was almost the same as the fraction for the accident conditions in NUREG-1536 and the fraction for the impact accident conditions in NUREG-2224 is 3×10−5, but the dose was also 100 times higher as the fraction for the fire accident conditions in NUREG-2224 is 3×10−3. In the case of the cooling time, it was confirmed that the dose change according to the cooling time was not significant because the dose contribution of transuranic elements having very long half-life was very large. In the case of the distance, it was confirmed that the dose decreased exponentially as the atmospheric dispersion factor decreased exponentially with the distance.

Meat affects color and quality by metabolite concentrations. Meat produces metabolites, and metabolites are caused by a variety of causes. Meat also produces metabolites by oxidation, which is an inevitable chemical process that meat undergoes which is resulting information of various chemical compounds. Thus, the aim of this study was to profiling the change of metabolites of M. longissimus lumborum during the storage at 4°C. Instrumental color measurements were showed decreasing chroma value, redness and yellowness (P<0.05) during storage, while non-significance (P>0.05) changes found in lightness value. Above all, hue angle was highest at 21 d of storage (P<0.05). The lipid and protein oxidation of muscles was measured by TBARS value significantly increased (P<0.05), thiol and carbonyl groups were also increased significantly (P<0.05) during the display. Total 19 of 60 identified compounds appeared to have a significant difference by storage time (P<0.05). Hue angle had a significant correlation with specific metabolites such as carbon disulfide, 3-methyl-1-butanol, 2-ethyl-1-hexanol, lactic acid and palmitic acid (P<0.05). Results of the current study provide the conversion of volatile and non-volatile metabolites and their correlation with oxidative indicators for changes in meat quality during aerobic storage.

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.

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.

Gryllus bimaculatus is one of many cricket species known as field crickets. Also known as the African or Mediterranean field cricket or as the two-spotted cricket, it can be discriminated from other Gryllus species by the two dot-like marks on the base of its wings. G.bimaculatus is a subtropical insect and widely distributed from Africa to south Asia. After into the country, The species are popular for use as a food source for insectivorous animals like spiders and reptiles kept as pets. In 2016, G.bimaculatus was approved as a general food ingredient by Korean Ministry of Food and Drug Safety. However, domestic research on G.bimaculatus is still in its study is beginning stages. G.bimaculatus is possible species to year-round rearing without storage condition. but The aim of the present study prepares for in case of problems such as breeding space, labor cost etc. In the laboratory condition at 28±2℃ and 50% relative humidity under 10h light, 12h dark photoperiod, Adult crickets oviposit at soaked flower foam for 24 hours. The experiment on the hatching of the eggs showed that eggs could be stocked at 16℃ for 10 days with 7 day pre-period after laying, representing 85% hatchability.

본 연구는 신품종 다래‘오텀센스’의 수확적기를 구명하고자 생육시기별 과실품질과 후숙 특성을 조 사하였다. 과실의 후숙은 과실의 비대가 최대가 되고 과실 내 종자가 성숙한 이후에 가능하였으나, 종 자가 성숙 상태만으로는 후숙 가능성을 판단할 수 없었다. 산함량은 1.05%이상이 되어야 정상적인 후 숙이 진행되었으며 후숙이 가능한 시점의 경도는 평균 27.1N이었다. 성숙기에 접근한 과실의 가용성 고 형물 함량은 만개후 71일부터 90일까지 시기별로 유의적인 차이가 없었지만 후숙 후의 가용성 고형물 함량에는 유의적 차이가 있어 가용성 고형물 함량으로 수확적기를 구명하기에는 어려움이 있었다. 다래 의 저장 중 중량감소율은 2℃에 상대습도 90%저장구가 낮았고, 부패율은 20℃, 상대습도 45% 저장구 에서는 저장 8일 후부터 증가하기 시작하였고, 2℃에 상대습도 45%와 상대습도 90% 모두 저장 후 20 일까지 10% 이하로 유지되었다. 따라서 과실의 크기, 경도 및 후숙 전·후의 가용성 고형물 함량 등을 종합하여 고려해 볼 때 신품종 다래‘오텀센스’의 수확적기의 만개 후 생육일수는 85일(9월 2일)이었 고, 2℃에 상대습도 90%인 저온고습환경이 적합하였다.

‘후지’ 사과의 MA 저장성 향상을 위해 저장 온도별로 적합한 비천공 breathable 필름 종류를 구명하고자 본 연구를 수행하였다. 저장중 생체중 감소율은 모든 저장 온도의 비천공 breathable 필름 처리구에서 저장 최종일까지 약 2.0% 이하를 나타냈다. 포장내 대기조성으로 볼 때 1oC에서 1,300cc 필름, 8oC에서 5,000cc 필름, 그리고 20oC에서 10,000cc 필름이 최적 MA 조건에 가장 근접하였다. 저장 중 포장내 에틸렌 농도는 모든 저장온도에서 산소 투과도가 가장 높았던 40,000cc 필름 처리구가 낮게 유지되었다. 저장 최종일의 1oC 1,300cc 필름이 당도, 비타민 C 함량, 그리고 외관 품질이 우수하였 고, 8oC 5,000cc 필름이 당도와 이취 정도가 양호하였으며, 그리고 20oC 10,000cc 필름이 경도와 외관상 품질이 높은 수치를 나타내었다. 이상의 결과로 포장내 대기조성과 과실의 내외적 품질을 비교한 결과 ‘후지’ 사과의 MA 저장시 1oC는 1,300cc 필름, 8oC는 5,000cc 필름, 그리고 20oC에서는 10,000cc 필름이 적합하다고 판단된다.

배추김치 제조 후 익힘 시간을 달리한 후 김치냉장고에 저 장한 김치의 이화학적 특성과 오르니틴 함량 변화를 조사하 기 위하여 익힘 및 저장 기간별 pH, 산도, 유산균 수 변화, 유산균 속 분포 및 오르니틴 함량 변화 패턴을 조사하였다. 배추김치는 조제 후 15℃에서 각 시간 별로 익힘 과정을 거 친 후 －1.4℃의 김치냉장고에 60일까지 보관하였다. 본 실험 에 사용한 시료는 익힘시간에 따라서 32 hr(S1), 36 hr(S2), 40 hr(S3), 44 hr(S4), 48 hr(S5)라 명명하였다. 김치냉장고 보관 모드로 전환하기 전 15℃에서의 저장 시간을 상대적으로 길 게 준 S5구에서 S1, S2구에 비하여 pH 감소가 좀 더 큰 것으 로 나타났으며, 보관 시간이 지남에 따라 pH가 4.3~4.4까지 낮아지는 것을 알 수 있었다. 젖산농도의 경우 15℃에서의 저 장 시간을 상대적으로 길게 준 S5구에서 젖산농도 증가가 좀 더 큰 것으로 나타났으며, 보관 시간이 지남에 따라 젖산농도 는 0.70~0.74까지 증가하는 것을 알 수 있었다. 유산균의 경우 모든 시료가 저장 초기 20일 경과까지 수가 급격히 증가하였 고, 20일 이후에는 S4, S5 시료가 S1, S2, S3 시료에 비하여 좀 더 증대되는 경향을 보였다. 유산균 속은 저장 40일 기준 으로 S5 시료에서 바이셀라 속 균이 50% 이상 검출되었다. 오르니틴 함량은 모든 시료에서 저장 40~50일차에 최대치를 보였으며, S4, S5 시료의 경우 오르니틴 함량은 100그램당 최 대 130 ㎎과 170 ㎎까지 증대되었다. 그러나 S1, S2, S3 시료 의 경우는 오르니틴 함량 증대 폭이 상대적으로 적었다. 이들 결과로부터 김치냉장고 조건에서 김치를 저장하기 전 15℃ 조 건에서 44~48시간을 발효한 후 김치냉장고에 40~50일 보관하 면 김치 100그램 중의 오르니틴 함량을 최대 130~170 ㎎까지 증대시킬 수 있을 것으로 판단되며, 그 중에서도 S5 (48 hr) 조건이 가장 우수한 것으로 조사되었다.