The domestic Pressurized Heavy Water Reactor (PWHR) nuclear power plant, Wolsong Unit 1, was permanently shut down on December 24, 2019. However, research on decommissioning has mainly focused on Pressurized Water Reactors (PWRs), with a notable absence of both domestic and international experience in the decommissioning of PHWRs. If proper business management such as radiation safety and waste is not performed, it can lead to increased business risks and costs in decommissioning. Therefore, the assessment of waste volume and cost, which provide fundamental data for the nuclear decommissioning process, is a crucial technical requirement before initiating the actual decommissioning of Wolsong Unit 1. Decommissioning radiation-contaminated structures and facilities presents significant challenges due to high radiation levels, making it difficult for workers to access these areas. Therefore, technology development should precede decommissioning process assessments and safety evaluations, facilitating the derivation of optimal decommissioning procedures and ensuring worker safety while enhancing the efficiency of decommissioning operations. In this study, we have developed a program to estimate decommissioning waste amounts for PHWRs, building upon prior research on PWR decommissioning projects while accounting for the specific design characteristics of PHWRs. To evaluate the amount of radioactive waste generated during decommissioning, we considered the characteristics of radioactive waste, disposal methods, packaging container specifications, and the criteria for the transfer of radioactive waste to disposal operators. Based on the derived algorithm, we conducted a detailed design and implemented the program. The proposed program is based on 3D modeling of the decommissioning components and the calculation of the Work Difficulty Factor (WDF), which is used to determine the time weighting factors for each task. Program users can select the cutting and packaging conditions for decommissioning components, estimate waste amount based on the chosen decommissioning method, and calculate costs using time weighting factors. It can be applied not only to PHWRs, but also to PWRs and non-nuclear fields, providing a flexible tool for optimizing decommissioning process.

Recently, with the increasing global demand for Ganoderma lucidum as a material for functional beverages, varieties with enhanced functionality are needed. As part of this effort, 10 strains were selected from a collection of 160 G. lucidum strains, based on their quantity and fruiting body characteristics. These included four strains collected in Korea, three in Japan, and three of unknown origin. Approximately 44% of the 1,290 hybrid strains were secured. After two rounds of bag cultivation in oak sawdust, three strains (G-20-4, G-20-5, and G-20-7) were ultimately selected for single-timbered cultivation. Among these, G-20-4 demonstrated the earliest harvesting with a large size and a bright cap. Additionally, this strain exhibited the highest levels of total glucan, β-glucan, total triterpenoid, total polyphenol, and total flavonoid content.

A facile and efficient method was developed to prepare highly stretchable and conductive graphene conductors with wrinkled structures by the mechanical stretching and shrinking of elastomeric substrates, in which graphene inks were printed on a prestretched elastomeric substrate. Stretchable and exfoliated graphene inks were prepared by mixing graphite and Ecoflex in a shear-assisted fluid dynamics reactor. The resultant graphene conductor exhibited excellent stretchability at 150% strain and high electrical conductivity of 64 ± 1.2 S m− 1. The resistance of the conductor did not change in bent, twisted, and stretched states. The resistance did not change during 10,000 cycles of stretching/releasing, with a maximum strain of 150%. Based on the graphene conductor, a stretchable conductometric sensor with a two-electrode configuration was fabricated to measure impedance changes at different concentrations of electrolyte ions. This sensor exhibited a good and linear sensitivity curve (298.61 Ω mM− 1, R2 = 0.999) in bent and stretched states.

With the aging of nuclear power plants (NPPs) in 37 countries around the world, 207 out of 437 NPPs have been permanently shutdown as of August 2022 according to the IAEA. In Korea, the decommissioning of NPPs is emerging as a challenge due to the permanent shutdown of Kori Unit 1 and Wolsong Unit 1. However, there are no cases of decommissioning activities for Heavy Water Reactor (HWR) such as Wolsong Unit 1 although most of the decommissioning technologies for Light Water Reactor (LWR) such as Kori Unit 1 have been developed and there are cases of overseas decommissioning activities. This study shows the development of a decommissioning waste amount/cost/process linkage program for decommissioning Pressurized Heavy Water Reactor (PHWR), i.e. CANDU NPPs. The proposed program is an integrated management program that can derive optimal processes from an economic and safety perspective when decommissioning PHWR based on 3D modeling of the structures and digital mock-up system that links the characteristic data of PHWR, equipment and construction methods. This program can be used to simulate the nuclear decommissioning activities in a virtual space in three dimensions, and to evaluate the decommissioning operation characteristics, waste amount, cost, and exposure dose to worker. In order to verify the results, our methods for calculating optimal decommissioning quantity, which are closely related to radiological impact on workers and cost reduction during decommissioning, were compared with the methods of the foreign specialized institution (NAGRA). The optimal decommissioning quantity can be calculated by classifying the radioactivity level through MCNP modeling of waste, investigating domestic disposal containers, and selecting cutting sizes, so that costs can be reduced according to the final disposal waste reduction. As the target waste to be decommissioning for comparative study with NAGRA, the calandria in PHWR was modeled using MCNP. For packaging waste container, NAGRA selected three (P2A, P3, MOSAIK), and we selected two (P2A, P3) and compared them. It is intended to develop an integrated management program to derive the optimal process for decommissioning PHWR by linking the optimal decommissioning quantity calculation methodology with the detailed studies on exposure dose to worker, decommissioning order, difficulty of work, and cost evaluation. As a result, it is considered that it can be used not only for PHWR but also for other types of NPPs decommissioning in the future to derive optimal results such as worker safety and cost reduction.

Despite the long history of mushroom use, studies examining the genetic function of mushrooms and the development of new varieties via bio-molecular methods are significantly lacking compared to those examining other organisms. However, owing to recent developments, attempts have been made to use a novel gene-editing technique involving CRISPR/Cas9 technology and genetic scissors in mushroom studies. In particular, research is actively being conducted to utilize ribonucleoprotein particles (RNPs) that can be genetically edited with high efficiency without foreign gene insertion for ease of selection. However, RNPs are too large for Cas9 protein to pass through the cell membrane of the protoplasmic reticulum. Furthermore, guide RNA is unstable and can be easily decomposed, which remarkably affects gene editing efficiency. In this study, nanoparticles were used to mitigate the shortcomings of RNP-based gene editing techniques and to obtain transformants stably. We used Lentinula edodes (shiitake mushroom) Sanjo705-13 monokaryon strain, which has been successfully used in previous genome editing experiments. To identify a suitable osmotic buffer for the isolation of protoplast, 0.6 M and 1.2 M sucrose, mannitol, sorbitol, and KCl were treated, respectively. In addition, with various nanoparticle-forming materials, experiments were conducted to confirm genome editing efficiency via the formation of nanoparticles with calcium phosphate (CaP), which can be bound to Cas9 protein without any additional amino acid modification. RNPs/NP complex was successfully formed and protected nuclease activity with nucleotide sequence specificity.

The purpose of this study was to breed a variety of stable productivity and high storage characteristics of white Hypsizygus marmoreus, which has high demand at domestic and global market due to a low bitter taste and the preference for white species. Accordingly, ‘Baekmaru’ was bred by hybridizing brown and white cap color species and backcrossing with white species. The ‘Baekmaru’ variety was bred by crossbreeding the brown and white species and backcrossing the white species. Through repeated cultivation of ‘Baekmaru’, a variety with a low contamination rate was selected when culturing the spawn for stable cultivation. As a results of demonstration test, the yield of ‘Baekmaru’ was 14% higher than that of the commercial variety. In addition, among the fruiting body characteristics of ‘Baekmaru’, diameter and thickness of the pileus were 16.43±15.27mm and 6.46±0.58mm, which were slightly higher than the commercial variety, and the hardness was 2.69±0.89N for the pileus and 3.09±0.89N for the stipe. The shelf life showed less change in thickness and color of pileus compared to commercial variety. The hardness of pileus of 'Baekmaru' was maintained in the range of 3.5 to 4.0N in the 4oC and 4oC and 20oC mixed treatment until 30 days of storage, and was higher than that of the commercial variety. Therefore, it was suggested to be excellent in storability.

As the importance of public health increases with the spread of infectious diseases, functionality has become a factor affecting consumers’ purchase of mushrooms. Therefore, the bioactive components of button mushrooms (Agaricus bisporus), which are generally known to promote button mushroom consumption, were analyzed. White and brown button mushrooms were compared and white beech mushroom (Hypsizygus marmoreus) were used as a control. White button mushrooms had higher sugar and inorganic potassium concentrations than brown button mushrooms, whereas sodium, magnesium, and vitamin C concentrations were not significantly different between the different button mushrooms. Moreover, there was approximately twice as much ergosterol in white button mushrooms than brown button mushrooms. Brown button mushrooms had higher concentrations of β-glucan and oxalic acid than white button mushrooms, but there was no significant difference in total organic acid content between the two mushroom types. High concentrations of the essential amino acids, ergothioneine, isoleucine, and leucine and the non-essential amino acids, glycine and alanine, were observed. Concentrations of the vitamin B group and total polyphenols were also high.

This study deals with replacement analysis of deteriorated equipment for improving productivity of production system. Frequent breakdown of the deteriorated equipment causes a situation that reduces productivity such as low product quality, process delay, and repair cost. However, the replacement of new equipment will be required a high initial investment cost, so it is important to analysis the economic feasibility. Therefore, we analyze the effect of the production system due to the aging effect of the equipment and the feasibility of equipment replacement based on the economic analysis. The process flow, working time, logistics movement, etc. are analyzed in order to build the simulation modeling for a ship and land switchboard production system. Using numerical examples, the economic feasibility analysis of equipment replacement through replacement of existing deteriorated equipment and additional arrangement of new facilities is performed.

수국은 수국과(Hydrnageaceae) 수국속(Hydrangea)에 속하는 낙엽관목 식물로 크고 화려한 화색과 화형을 가져 절화, 분화 뿐만 아니라 정원용으로도 전세계적으로 인기있는 식물이다. 본 연구는 SSR 마커를 이용하여 교배에 사용된 5가지 수국 품종에 대한 유전적 유연관계를 조사하고 교배 조합 별 종자의 형성과 발아율을 조사하여 품종간 화합성과 불화합성을 확인, F1의 화서와 잎 모양의 유전 양상을 조사하기 위해 수행 하였다. 군집분석 결과 Hydrangea macrophylla와 H. serrata 로 크게 두가지 그룹으로 나뉘었고 교배결과 종내 교배와 H. macrophylla를 모본으로 종간 교배를 했을 때 획득 자손의 수에 차이가 거의 없어 두 종간 친화성이 확인되었다. 자가 수 분을 통한 종자형성은 어렵거나 생기더라도 발아가 되지 않아 자가불화합성이 있는 것으로 확인되었다. 또, 2018년 H. macrophylla와 H. serrata를 교배에 사용하여 총 9개 교배조 합을 통해 1,807개의 F1을 얻었고 교배 조합들 간 자손을 이용하여 화서의 유전 양상과 화서에 따른 잎의 형태를 조사하여 화서와 잎 모양의 관계를 보았다. 그 결과, 모본 또는 부본에 편평형이 있다면 F1 전체 편평형의 화서 유형을 보였다. 화서 모양이 원형인 자손은 원형 화서 끼리의 교배를 통해서만 얻었다. 또, 원형의 자손의 잎은 전체적으로 엽폭과 엽장이 비슷 한 원형에 가까웠고, 편평형 자손들의 잎 모양은 엽장이 엽폭 보다 큰 길쭉한 타원형에 가까웠다. 그 중, 편평형과 원형의 혼합 교배를 통해 얻어진 F1 자손들에서는 잎의 모양이 원형 과 타원형의 중간형태임을 확인하였다. 이를 통해, 화서의 형 태는 단일 유전자에 의한 우성 열성 유전임을 확인하였고 잎은 화서 유형과 연관되어 있으며 중간 유전 형태임을 확인하 였다. 본 연구결과는 수국의 유전 육종에 관한 기초자료로써 교배 조합 작성 단계 또는 1년생 실생의 잎 모양을 통한 빠른 화서 모양 선발과 분리가 가능하여 육종 기간 단축을 기대할 수 있을 것이다.

현재 양송이 품종의 개발은 1980년대에 개발된 방법에 의존하여 진행되고 있다. 유전자가위를 이용한 유전자교정 기술이 다양한 분야에서 각광받고 있고, 이 기술을 버섯 육종에도 적용하기 위하여 진행된 이 연구에서는, CRISPR/Cas9 활용에 필수적인 원형질체 분리 효율을 1.0 × 10 8 /mL까지 안정적으로 끌어올렸고, spermidine을 이용하여PEG 형질전환의 효율 또한 기존 방법에 비해 100배가량 끌어올렸음을 보고한다.

현재 양송이 종균은 1980년대 개발된 방법으로 제조되고 있어, 양송이 종균 품질 향상을 위한 새로운 제조 방법을 개발하였다. 그 결과 균사체량이 5.92±0.52 g/L로 가장 많이 배양된 CDB(compost dextrose broth) 배지에서 24oC에서 120 rpm으로 진탕 배양(24시간/일) 하는 통기 식(2.5 L/min) 액체배양법으로 배양기간 10일이 액체 접종원 사용으로 양호했으며, 양송이 밀 배지 종균 생산은 밀 배지 50 g당 액체 접종원 1 ml을 적정 접종량으로 하여 10일 배양하면 종균의 뭉침과 흔드는 작업없이 적절하게 배양되었음을 보고한다.

기후변화에 대비하여 고온성 양송이 백색 품종을 육성한 결과는 다음과 같다. 모본은 KMCC00540, KMCC00591, KMCC00643을 선발하였고, ISSR과 SSR마커로 각각 동 핵균주를 선발하여 교잡하였다. 선발 교잡주를 고온 20~25 o C, 습도 80% 이상에서 3반복으로 재배하여 농업적 형질과 자실체 특성의 변이가 가장 적은 것은 Abs4-2016- 121 계통이었다. 이 계통은 KMCC00000와 KMCC0000를 교잡한 계통이며, 경주와 부여 농가에서 현장실증시험결과 Abs4-2016-121 계통이 자실체 경도가 높으며 고온에서 갓 개열이 지연되어 고온성 품종 ‘하담’으로 육성하였다.