In KNF, fuel performance analysis modules were developed to predict the overall behavior of a fuel rod under normal operating conditions. Their main focus is to provide information on initial conditions prior to dry storage. Potential degradation mechanisms that may affect sheath integrity of spent CANDU fuel during dry storage are: creep rupture under internal gas pressure, sheath oxidation in air environment, stress corrosion cracking, delayed hydride cracking, and sheath splitting due to UO2 oxidation for a defective fuel. To upgrade the developed modules that address all the damage mechanisms, the first step was a review of the available technical information on phenomena relevant to fuel integrity. The second step was an examination of the technical bases of all modules, identify and extend the ranges of all modules to required operating ranges. The 300°C spent CANDU fuel sheath temperature metric for dry storage ensures spent CANDU fuel element integrity from the failure mechanisms of creep rupture, oxidation and stress corrosion cracking at a failure probability of 2×10-5 for a dry storage time of 100 years. The 300°C sheath temperature metric for dry storage has relatively a lower failure rate than the target criteria for dry storage of spent LWR fuel. Although different modes of failure were treated separately for simplicity, ignoring possible synergistic effects, these results are conservative because of the conservative assumptions that have been made for evaluating spent fuel element conditions, and because of the inherent conservatism of the applied models. Additional conservatism of the model comes from the fact that isothermal conditions do not prevail in actual storage conditions. Further R&D being considered includes acquisition of new functional models to implement overall fuel behavior evaluation and cover spent CANDU fuel in dry storage, and upgrades of the analysis module to achieve sufficient accuracy in key output parameters. The developed modules provide a platform for research and industrial applications, including the design of fuel behavior experiments and prediction of safe operating margins for spent CANDU fuel.

Recent progress has been made to establish intestinal organoids for an in vitro model as a potential alternative to an in vivo system in animals. We previously reported a reliable method for the isolation of intestinal crypts from the small intestine and robust three-dimensional (3D) expansion of intestinal organoids (basal-out) in adult bovines. The present study aimed to establish next-generation intestinal organoids for practical applications in disease modeling-based host-pathogen interactions and feed efficiency measurements. In this study, we developed a rapid and convenient method for the efficient generation of intestinal organoids through the modulation of the Wnt signaling pathway and continuous apical-out intestinal organoids. Remarkably, the intestinal epithelium only takes 3-4 days to undergo CHIR (1 µM) treatment as a Wnt activator, which is much shorter than that required for spontaneous differentiation (7 days). Subsequently, we successfully established an apical-out bovine intestinal organoid culture system through suspension culture without Matrigel matrix, indicating an apical-out membrane on the surface. Collectively, these results demonstrate the efficient generation and next-generation of bovine intestinal organoids and will facilitate their potential use for various purposes, such as disease modeling, in the field of animal biotechnology.

Prior to the investigations on fuel degradation it is necessary to describe the reference characteristics of the spent fuel. It establishes the initial condition of the reference fuel bundle at the start of dry storage. In a few technology areas, CANDU fuels have not yet developed comprehensive analysis tools anywhere near the levels in the LWR industry. This requires significantly improved computer codes for CANDU fuel design. In KNF, in-house fuel performance code was developed to predict the overall behavior of a fuel rod under normal operating conditions. It includes the analysis modules to predict temperature, pellet cracking and deformation, clad stress and strain at the mid-plane of the pellet and pellet-pellet interfaces, fission gas release and internal gas pressure. The main focus of the code is to provide information on initial conditions prior to dry storage, such as fission gas inventory and its distribution within the fuel pellet, initial volumes of storage spaces and their locations, radial profile of heat generation within the pellet, etc. Potential degradation mechanisms that may affect sheath integrity of CANDU spent fuel during dry storage are: creep rupture under internal gas pressure, sheath oxidation in air environment, stress corrosion cracking, delayed hydride cracking, and sheath splitting due to UO2 oxidation for a defective fuel. To upgrade the developed code that address all the damage mechanisms, the first step was a review of the available technical information on phenomena relevant to fuel integrity. The second step was an examination of the technical bases of all modules of the in-house code, identify and extend the ranges of all modules to required operating ranges. Further improvements being considered include upgrades of the analysis module to achieve sufficient accuracy in key output parameters. The emphasis in the near future will be on validation of the in-house code according to a rigorous and formal methodology. The developed models provide a platform for research and industrial applications, including the design of fuel behavior experiments and prediction of safe operating margins for CANDU spent fuel.

The bacterial soft-rot disease is one of the most critical diseases in vegetables such as Chinese cabbage. The researchers isolated two bacteria (Pseudomonas kribbensis and Pantoea vagans) from diseased tissue samples of Chinese cabbages and confirmed them as being the strains that cause soft-rot disease. Lactic-acid bacteria (LAB), were screened and used to control soft-rot disease bacteria. The researchers tested the treatments with hypochlorous acid water (HAW) and LAB supernatant to control soft-rot disease bacteria. The tests confirmed that treatments with the HAW (over 120 ppm) or LAB (Lactobacillus plantarum PL203) culture supernatants (0.5 mL) completely controlled both P. kribbensis and P. vagans.

This study was carried out to explore possibilities of cultivating horticultural crops in the air-dome greenhouse in comparison to the common iron-frame greenhouse as the standard. The levels of carbon dioxide and atmospheric pressure measured inside the air-dome greenhouse turned out to be higher than those measured inside the iron-frame greenhouse. Contrastingly, light intensity was relatively weaker inside the air-dome greenhouse due to the air-inflated double layers. Plants of melon and cherry tomato were cultivated from May 2 to August 12, 2016, respectively in the two greenhouses. For melon plants, growth in the air-dome greenhouse effectively increased fruit weight as well as trunk circumference compared to iron-frame greenhouse. Moreover, soluble sugar content of melon fruit was significantly higher when cultivated in the air-dome greenhouse. For cherry tomato plants, fruit yield of cherry tomato was significantly increased inside the air-dome greenhouse. Furthermore, it has been found that the air-dome greenhouse was considerably effective in shortening the growing period of melon and cherry tomato plants in comparison to the iron-frame greenhouse.

This study was conducted to investigate exact life cycle and Parnassius bremeri’s response to heat shock stress from 2012 to 2016 in Holoce Ecosystem Conservation Research Institution through captive breeding. About 16 days(15.7±0.3days) later embryo in eggs were developed as pharate first instar and the eggs of Parnassius bremeri possessed the ability to undergo an extended aestivation hosting a fully developed pharate 1st instar larvae within the chorion. Pharate 1st instar in egg hatched from late in November to early in December about 194 days(194.3±1.1days) later. All pharate 1st instar in egg and out of egg survived at 25℃, 35℃. In case of 45℃ survival rate of pharate 1st instar in an egg (93.8±6.3%) was significantly higher than those (22.2±10%) of pharate 1st instar out of an egg. All was dead at 47.5, 50, 52.5 and 55℃.

Methyl Bromide (MB) has been regulated by montreal protocol due to ozone depletion since 1992, and there is a need to develop MB alternative fumigation methods. To find out the efficacies and tolerance in developmental stages of citrus mealybugs (Planococcus citri) which frequently infested in imported pineapples, phosphine(PH3) gas was tested in different exposure times (2~24 hr) and concentrations (0.1∼2g/m3) in small desiccators at 8℃. Based on Lethal 99% concentration × time products (LCTP 99%) of PH3 gas to target developmental insect, 2g/m3 PH3 was applied for 24 hr in 300 m3 fumigation facility, which was designed in well sealed and evacuation system (5 air exchange/min). We monitored PH3 gas in fumigation facility to confirm CTP and checked PH3 gas in atmospheres in air ventiliation process after fumigations to make quarantine guideline and protocol for worker safety as well as efficacy to target pest.

전해정련을 이용한 폐 피복관 처리의 타당성을 살펴보기 위하여, 500℃의 LiCl-KCl 용융염 내에서 표면이 산화된 10 g 규모의Zircaloy-4 피복관 및 순수한 Zircaloy-4 피복관의 전기화학적 거동을 살펴보았다. 산화된 Zircaloy-4 피복관이 담긴 basket을 작업전극으로하여 전압-전류 관계를 측정한 결과, 산화되지 않은 Zircaloy-4 피복관과 비교해 Zr의 산화 peak는 Ag/AgCl 기준전극 대비, 약 -0.7 V ~ -0.8 V로 유사한 반면, 산화 전류의 크기는 확연하게 감소하는 것으로 나타난다. 이러한 결과는 -0.78V의 일정전위를 가한 전기화학적 용해 실험에서 살펴본 전류-시간 곡선에서도 유사하게 나타나며, 피복관 조각들의 평균 두께 및 무게 변화로부터 확인할 수 있다. Zircaloy-4 피복관이 산화되었을 경우, 표면의 산화막이 피복관의 전도성에 영향을 주어 basket 내 위치에 따라 전기화학적 용해의 균일성 및 속도를 떨어뜨리는 것으로 나타나지만, 표면의 미세한 결함과 Zr 산화물의 상 특성으로 인해 전기화학적 용해가 진행되는 것으로 판단된다.

Actias artemis is a members of the family Saturniidae, also known as wild silkmoths, have impressive color and size. In 2012, estimation of Actias artemis (Lepidoptera: Saturniidae) abundance in HECRI was conducted using the mark-release-recapture (MRR) method (Jolly, 1965) from mid to late May. Seven sampling events were accomplished from 19 May, 21 May, 22 May, 24 May, 26 May, 28 May and on 30 May, during the main flight of the species. Marking was made by writing numbers in the hind wing of each individual moths. Most collections were undertaken by a team of experienced four or six researches of HECRI using light trap (mercury lamp: 250W). Seven female and 58 male moths were captured in study site. The effective population size of Actias artemis was 24.9 and heterozygosity was more than 97%. Seven marked moths were recaptured, resulting in 9.7% of recapture rate. The estimated population size of A. artemis showed a peak by 133 individuals on 22 May and then declined. The estimated adult numbers of A. artemis using MRR method from minimum 168 to maximum 5,332 (p<0.05).

The ferroelectric properties of barium titanate strongly depend on its microstructure, in particular, grain size and distribution. During sintering, usually exhibits abnormal grain growth, which deteriorates considerably the ferroelectric properties. A typical technique to suppress the abnormal grain growth is the addition of dopants. Dopant addition, however, affects the ferroelectric properties and thus limits the application of . Here, we report a simple but novel technique to prevent the abnormal grain growth of and to overcome the limitation of dopant use. The technique consists of stepwise sintering in a reducing atmosphere and in an oxidizing atmosphere. The materials prepared by the present technique exhibit uniform grain size and high dielectric properties. The technique should provide opportunities of having -based materials with superior ferroelectric properties.