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.

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.

Chamaecyparis obtusa is one of the economical conifers planted in Korea due to its good quality timber and wood characteristics. Individuals of C. obtusa containing high terpenes (HT) and low terpenes (LT) were selected for by colorimetric method. The HT of C. obtusa was delayed in wilting against various abiotic stresses compared to the LT plants. The HT group exposed to UV did not significant influence the chlorophyll content, and the chlorophyll value was higher in the HT group than the LT group. Also, chilling treatment (5℃) did not significant influence on the chlorophyll content. However treatment at -4℃ showed relatively low chlorophyll content in the LT group than the HT group. Plants exposure to high temperature was not a difference between the HT and the LT group. However, treatment at 38℃ influenced the chlorophyll content that was increased exposure time-dependently. In salt treatments, chlorophyll in the HT group was lower at high concentrations (300 and 500 mM) of NaCl. However, chlorophyll content increased to slightly in treatment time-dependently, which is 6.7% to 40%. H2O2 treatment has been a negative effect on the chlorophyll content in the HT group. All concentration of H2O2 decreased the chlorophyll content of 5% to 35%. Plants containing high terpenoids were resisted against some abiotic stress such as salt and H2O2. Our results implied that terpenoids could cause various abiotic stress resistance. These results could be utilized for efficient management and biomass production during forest silvicultures.

Pesticide application in agriculture provides significant benefits such as protection from disease, prevention of harmful insects, and increased crop yields. However, accurate toxicological tests and risk assessments are necessary because of many related adverse effects associated with pesticide use. In this review, we discuss and analyze residual pesticides contained in livestock feed in Korea. A pesticide residue tolerance standard for livestock feed has not been precisely established; so, risk assessments are required to ensure safety. Standards and approaches for animal criteria and appropriate methods for evaluating residual pesticides are discussed and analyzed based on technology related to animal product safety in Korea. The safety of livestock feed containing pesticides is assessed to establish maximum residue limits relative to pesticides. Analysis of residual pesticides in milk, muscle, brain, and fat was performed with a livestock residue test and safety evaluation of the detected pesticide was performed. Efficacy of organic solvent extraction and clean-up of feed was verified, and suitability of the instrument was examined to establish if they are effective, rapid, and safe. This review discussed extensively how pesticide residue tolerance in livestock feed and hazard evaluation may be applied in future studies.

Ampelopsis brevipedunculata, a porcelain berry that is a kind of Korean domestic wild berry (Viticeae), has been known to be resistant to diseases and insects. A total of 2,622 unigenes containing 912 contigs and 1,710 singletons were obtained by sequencing 5,839 expressed sequence tag (EST) clones derived from the cDNA library of wild grape, A. brevipedunculata. In the gene ontology analysis, 1,175 genes related to biological process, 1,516 genes related to molecular function, and 1,413 ones related to cell components were annotated. Among the genes showing molecular function, 17 clones were classified into defense-related genes, and 102 were known to be related with responses to stress in plants. Domains, such as leucine-rich repeat, Serine/threonine protein kinase-related, WD40 repeat, EF-hand calcium-binding, pentatricopeptide repeat, and pathogenesis-related transcriptional factor were highly expressed. Genes encoding defense related proteins, such as chitinase, catalase, protein-serine/threonine kinases, were also clustered into an abundant group in cDNAs from A. brevipedunculata. Approximately, 80 simple sequence repeats with 2~5 nucleotides were detected in the cDNAs of A. brevipedunculata. These data could provide useful information for the genetic analysis of wild grapevines and in programs for breeding grape cultivars.

Tyrophagus putrescentiae (Tp) as a storage mite inhabitats in stored grains, hay, and straw at agricultural areas. T. putrescentiae stimulates an immune response and triggers inflammatory cytokines release, and thus it is a source of allergen that sensitize and induce allergic reactions. Also, T. putrescentiae has been reported to cause asthma and atopic disease by cross-reactivity with Dermatophagoides pteronyssinus (Dp). The study on T. putrescentiae in human monocytic THP-1 cells is not enough to understand cytokine expression and pathological mechanisms. The aim of this study is to investigate the effect of T. putrescentiae extract (TpE) on production of inflammatory cytokines and expression of mRNA level in THP-1 cells. THP-1 cells are treated with TpE and supernatants were analyzed for the production of cytokines using enzyme-linked immunosorbent assay (ELISA). mRNA level in the culture cells was measured by a reverse transcriptase-polymerase chain reaction (RT-PCR). As a result of this study, TpE significantly induced secretion of interleukin-6, interleukin-8, and monocyte chemotactic protein-1 (MCP-1) in THP-1 cells in time- and dose-dependent manner. These results suggest that TpE may play a role in contributing to inflammatory disease through stimulation of immune cell. Further research of T. putrescentiae is needed to understand the elucidation of the pathogenic mechanism.

Chronic inflammatory diseases such as Crohn′s disease and ulcerative colitis are associated with increased risk of colon adenocarcinoma. Apoptic induction of colon cancer cells by cytokines and death receptors is an important anti-cancer therapy. We observed that co-administration of TNFα and IFNγ in human colon cancer cell line, HCT116, resulted in cell death and expression of IL-32. Cleavage forms of caspase-3, caspase-9, and PARP were increased in TNFα / IFNγ-treated HCT116. mRNA expression of death receptors, including TNFR1 and Fas were not changed and NO generation was not induced by combination of TNFα and IFNγ. However, mRNA expression of IL-32α, β, and γ was increased in TNFα / IFNγ-treated HCT116. To determine the effect of IL-32 in HCT116 cell apoptosis by TNFα / IFNγ stimulation, IL-32 siRNA-transfected HCT116 cells were cultured with TNFα / IFNγ and cell proliferation was measured. IL-32 siRNA induced slight recovery of cell viability of TNFα / IFNγ-stimulated HCT116. These results suggest that IL-32 is not directly related to apoptosis of HCT116 by TNFα / IFNγ stimulation. However, IL-32 expression by TNFα or TNFα / IFNγ in a colon cancer cell line is very interesting because of the unknown effect of IL-32 in colon cancer. Our study will contribute to development of studies for IL-32 function in human colon cancer and anti-cancer therapies using cytokines.