고자리꽃파리는 양파 및 마늘 등 백합과 Allium 속에 속하는 농작물에 중요한 해충으로 전 세계적으로 온대지역에 서 경제적 해충으로 취급하고 있다. 본 연구에서는 기존 자료를 바탕으로 월동번데기의 성충으로 우화모델를 작성하 고 포장 실측자료와 비교하여 평가하였다. 월동번데기 발육모형으로 선형과 비선형모형을 작성하고 발육기간 분포 모형과 결합하여 예찰모형을 작성하였다. 비선형발육모형 작성시 3-매개변수 락틴모형 적용뿐만 아니라 4-매개변 수 모형의 마지막 변수 값을 선형모형의 절편값으로 대체하여 저온에서 선형성이 강화도록 변형시켰다. 성충우화 50% 예측에서 일일평균온도를 이용하는 경우 적산온도 모형을 비롯하여 발육률 적산모형(선형식 및 비선형식) 모두 실측치와 큰 차이가 있었다. 시간별온도를 입력값으로 한 경우 3-매개변수 모형을 제외한 사인곡선 적산온도 모형, 선형 발육률 적산모형, 4-매개변수 비선형 발육률 적산모형의 평균편차는 3일과 차이가 없었다. 최종적으로 선형모형 및 4-매개변수 비선형모형을 바탕으로 시간별온도자료를 이용한 발육률 적산모형은 선발하였다. 그 결과 선형 발육률 적산모형이 두 포장적합 집단(1984, 1987)에서 실측일과 편차가 3일과 차이가 없었다. 비선형 발육률 적산모형은 1984년 적합은 0.8일 편차로 정확하였으나 1987년 집단에서 평균편차가 6.5일로 다소 증가하였다.

The Japanese pine sawyer (JPS), Monochamus alternatus Hope, is an important vector of the pine wood nematode, Bursaphelenchus xylophilus (Steiner and Buhrer), which causes pine wilt disease. JPS selects a characteristic life cycle of a four- or five-instar pathway, which indicates the number of instars before pupation. In this study, we investigated the potential presence of a three-instar pathway and sought to determine the minimum larval age required for JPS to construct a pupal chamber. The results showed that no third instars made pupal chambers, suggesting that there is no three-instar pathway. The initiation time of digging the tunnel to make the pupal chamber ranged widely from Julian date 274 (30 September) to 332 (27 November). This timing became an average age stage of 4.8 instar, which equals an 80% completion of the fourth instar. Thus, the minimum larval age at which JPS constructs the tunnel to pupate the next year is estimated to be late in the fourth larval instar. Further, we discuss the diapause ecology in relation to the larval development of JPS in different thermal environments. Tentatively, we suggest that the regulation of diapause induction in JPS involves a dual process of reaching a critical developmental stage and stimulus (tentatively a cold temperature). This hypothesis will be helpful for future studies of diapause mechanisms and the selection of the instar-pathway in JPS and related species.

The clearwing moth, Synanthedon bicingulata (Staudinger, 1887), is a pest that infests various species of cherry trees. However, genetic information regarding the genus Synanthedon including S. bicingulata, is limited. In this study, we sequenced a complete mitochondrial genome (mitogenome) of the species. The 16,255 bp of S. bicingulata mitogenome differs from the typical gene arrangement formed in Lepidoptera: trnQ-trnS2-trnM-trnI arrangement between the A+T-rich region and the ND2 junction. Moreover, the genome has untranslated repetitive sequences in the intergenic space between lrRNA and trnV, as well as the CGA start codon in COI and the TTG start codon in ATP8. Similar observations are noted in species belonging to the tribe Synanthedonini within the genus Synanthedon.

본 연구는 검거세미밤나방(Agrotis ipsilon) 성페로몬 트랩에 혼재하여 유살되는 은무늬밤나방아과 형태적 분류와 동정법 수립을 위해, 날개 무늬의 형태계측학 분석을 실시하였다. 은무늬밤나방아과 개체는 2023년 11월 부터 12월까지 제주도 애월읍 일대에서 채집되었으며, 콩 해충으로 알려진 콩은무늬밤나방(Ctenoplusia agnata) 을 비롯하여, 다양한 농작물을 가해하는 것으로 알려진 붉은금무늬밤나방(Chrysodeixis eriosoma)의 수컷 성충이 포획되었다. 앞날개의 형태 및 무늬를 가지고 현장에서 쉽게 동정할 수 있는 형태적 특징을 도출하기 위하여, 각 성충 개체의 앞날개를 잘라 현미경 카메라로 촬영하고, 앞날개의 내횡선, 아외연선, 반점 크기 등 15개의 형질 을 측정하였다. 또한 각 형질 간의 상관관계를 분석하였으며 빈도분포를 통하여 두 종간 분리되는 형질을 파악하 였다. 최종적으로 다변량 분석법을 적용하여 두 집단이 어떻게 군집을 이루는지 분석하고, 날개형태만으로 붉은 금무늬밤나방과 콩은무늬밤나방을 구분할 수 있는 방안을 제시하였다.

Tropilaelaps mercedesae Anderson and Morgan, 2007 (Acari: Laelapidae) is a serious ectoparasite of the brood of several honey bee species. Among the four recognized species of Tropilaelaps, Korean population was renamed as T. mercedesae from T. clareae on the basis of morphological evidences and genetic data. In this study, we report the complete mitochondrial genome (mitogenome) sequence of T. mercedesae. The 15,119-bp long mitogenome has an identical gene arrangement to that of Chinese sample reported previously. Comparison of two geographic samples showed COII, ND5, ND4, ND6, CytB, and ND1 to have higher number of variable sites than COI, which is often used for population-level study, suggesting these genes to have potential usefulness for population genetic study. The mitogenome sequence of T. mercedesae from Korea could be useful for species identification for geographic samples, trace of the origin of local populations, and illustration of evolutionary distinction among Tropilaelaps species either using part of or whole genome.

In this study, we examined the antagonistic effects of sprout-borne lactic acid bacteria (LAB) on Salmonella enterica serovar Enteritidis. This antagonism is promoted as a means of controlling contamination during sprout production and provides additional LAB for consumers. We isolated a total of 24 LAB isolates in nine species and five genera from seven popular vegetable sprouts: alfalfa (Medicago sativa), clover (Trifolium pratense), broccoli (Brassica oleracea ssp. italica), vitamin (B. rapa ssp. narinosa), red radish (Raphanus sativus), red kohlrabi (B. oleracea var. gongylodes), and Kimchi cabbage (B. campestris var. pekinensis). Based on 16S rRNA gene sequences, the LAB species were identified as Enterococcus casseliflavus, E. faecium, E. gallinarum, E. mundtii, Lactococcus taiwanensis, Leuconostoc mesenteroides, Pediococcus pentosaceus, and Weissella cibaria, and W. confusa. A total of 16 LAB isolates in seven species including E. faecium, E. gallinarum, E. mundtii, L. taiwanensis, L. mesenteroides, P. pentosaceus, and W. cibaria showed antagonistic activity toward S. enterica. The growth inhibition of sprout LAB on S. enterica was confirmed by co-culture. Unexpectedly, sprout LAB failed to suppress the growth of S. enterica in alfalfa sprouts, whereas all LAB strains stimulate S. enterica growth even if it is not significant in some strains. The findings of this study indicate that S. enterica-antagonistic LAB are detrimental to food hygiene and will contribute to further LAB research and improved vegetable sprout production.

When the parent radionuclide decays, the progeny radionuclide is produced. Accordingly, the dose contribution of the progeny radionuclide should be considered when assessing dose. For this purpose, European Commission (EC) and International Atomic Energy Agency (IAEA) provide weighting factors for dose coefficient. However, these weighting factors have a limitation that does not reflect the latest nuclide data. Therefore, in this study, we analyzed the EC and IAEA methodology for derivation of weighting factor and used the latest nuclide data from ICRP 107 to derive weighting factors for dose coefficient. Weighting factor calculation is carried out through 1) selection of nuclide, 2) setting of evaluation period, and 3) derivation based on ICRP 107 radionuclide data. Firstly, in order to derive the weighting factor, we need to select the radionuclides whose dose contribution should be considered. If the half-life of progeny radionuclides sufficiently short compared to the parent radionuclide to achieve radioactive equilibrium, or if the dose coefficient is greater of similar to that of the parent radionuclide and cannot be ignored, the dose contribution of the progeny radionuclide should be considered. In order not to underestimate the dose contribution of progeny radionuclides, the weighting factors for the progeny nuclides are taken as the maximum activity ratio that the respective progeny radionuclides will reach during a time span of 100 years. Finally, the weighting factor can be derived by considering the radioactivity ratio and branch fraction. In order to calculate the weighting factor, decay data such as the half-life of the radionuclide, decay chain, and branch fraction are required. In this study, radionuclide data from ICRP 107 was used. As a result of the evaluation, for most radionuclides, the weighting factors were derived similarly to the existing EC and IAEA weighting factors. However, for some nuclides, the weighting factors were significantly different from EC and IAEA. This is judged to be a difference in the half-life and branch fraction of the radionuclide. For example, in the case of 95Zr, the weighting factor for 95mNb showed a 35.8% difference between this study and previous study. For ICRP 38, when 95Zr decays, the branch fraction for 95mNb is 6.98×10-3. In contrast, for ICRP 107, the branch fraction is 1.08×10-2, a difference of 54.7%. Therefore, the weighting factor for the dose coefficient based on ICRP 107 data may differ from existing studies depending on the half-life and decay information of the nuclide. This suggests the need for a weighting factor based on the latest nuclide data. The results of this study can be used as a basis for the consideration of dose contributions for progeny radionuclides in various dose assessments.

The demand for transportation is increasing due to the continuous generation of radioactive wastes. Especially, considering the geographical characteristics of Korea and the location characteristics of nuclear facilities, the demand for maritime transportation is expected to increase. If a sinking accident happens during maritime transportation, radioactive materials can be released into the ocean from radioactive waste transportation containers. Radioactive materials can spread through the ocean currents and have radiological effects on humans. The effect on humans is proportional to the concentration of radioactive materials in the ocean compartment. In order to calculate the concentration of radioactive materials that constantly flow along the ocean current, it is necessary to divide the wide ocean into appropriate compartments and express the transfer processes of radioactive materials between the compartments. Accordingly, this study analyzed various ocean transfer evaluation methodologies of overseas maritime transportation risk codes. MARINRAD, POSEIDON, and LAMER codes were selected to analyze the maritime transfer evaluation methodology. MARINRAD divided the ocean into two types of compartments that water and sediment compartments. And it was assumed that radionuclides are transfered from water to water or from water to sediment. Advection, diffusion, and sedimentation were established as transfer process for radionuclides between compartments. MARINRAD use transfer parameters to evaluate transer processes by advection, diffusion, and sedimentation. Transfer parameters were affected by flow rate, sedimentation rate, sediment porosity, and etc. POSEIDON also divided the ocean into two types that water and sediment compartment, each compartments was detaily divided into three vertical sub-compartment. Advection, diffusion, resuspension, sedimentation, and bioturbation were established as transport processes for radionuclides between compartments. POSEIDON also used transfer parameters for evaluating advection, diffusion, resuspension, sedimentation, and bioturbation. Transfer parameters were affected by suspended sediment rates, sedimentation rates, vertical diffusion coefficients, bioturbation factors, porosity, and etc. LAMER only considered the water compartment. It divided the water compartment into vertical detailed compartments. Diffusion, advection and sedimentation were established as the nuclide transfer processes between the compartments. To evaluated the transfer processes of nuclides for diffusion and advection, LAMER calculated the probability with generating random position vectors for radionuclides’ locations rather than deterministic methods such as MARINRAD’s transfer parameters or POSEIDON’s transfer rates to evaluate transfer processes. The results of this study can be used as a basis for developing radioactive materials’ ocean transfer evaluation model.

The operation of nuclear facilities involves the potential for on-site contamination of soil, primarily resulting from pipe leaks and other operational incidents. Globally, decommissioning process for commercial nuclear power plants have revealed huge-amounts of soil waste contaminated with Cs-137, Sr-90, Co-60, and H-3. For example, Connecticut Yankee in the United States produced approximately 52,800 ton of contaminated soil waste, constituting 10% of the total waste generated during its decommissioning. Environmental remediation costs associated with nuclear decommissioning in the US averaged $60 million per unit, representing a significant 10% of the whole decommissioning expenses. Consequently, this study undertook a preliminary investigation to identify important factors for establishing a site remediation strategy based on radionuclide- and site-specific media- characteristics, focusing the efficiency enhancement for the environmental remediation. The factors considered for this investigation were categorized into physical/environmental, socioeconomic, technical, and management aspects. Physical/environmental factors contained the site characteristics, contamination levels, and environmental sensitivity, while socio-economic factors included the social concerns and economic costs. Technical and management factors included subcategories such as technical considerations, policy aspects, and management factors. Especially, technical factors were further subdivided to consider the site reuse potential, secondary waste generation by site remediation, remediation efficiency, and remediation time. Additionally, our study focused the key factors that facilitate the systematic planning for the site remediation, considering the distribution coefficient (Kd) and hydrogeological characteristics associated with each radionuclide in specific site conditions. Therefore, key factors in this study focus the geochemical characteristics of site media including the particle size distribution, chemical composition, organic and inorganic constituents, and soil moisture content. Moreover, the adsorption properties of site media were examined concerning the distribution coefficient (Kd) of radionuclides and their migration characteristics. Furthermore, this study supported the development of a conceptual framework, containing the remediation strategies that incorporate the mobility of radionuclides, according to the site-specific media. This conceptual framework would necessitate the spatial analysis techniques involving the whole contamination surveys and radionuclide mobility modeling data. By integrating these key factors, the study provides the selection and simulation of optimal remediation methods, ultimately offering the estimated amounts of radioactive waste and its disposal costs. Therefore, these key factors offer foundational insights for designing the site remediation strategies according the sitespecific information such as the distribution coefficient (Kd) and hydrogeological characteristics.

In Korea, most temporary storage facilities for spent nuclear fuel are nearing saturation. As an alternative to this, the 2nd basic plan for high-level radioactive waste management specified the operation plan of dry interim storage facility. Meanwhile, the NSSC No. 2021-19 stipulates that it is necessary to evaluate the possibility and potential effect of accident before operating interim storage facility. Therefore, this study analyzed the categories of accident scenarios that may occur in dry storage facility as part of prior research on this. We investigated the case of categorization of dry storage facility accident scenarios of IAEA, NRC, KAREI, and KINS. The IAEA presented accident scenarios that could occur in on-site dry storage facility operated with silo and cask method. NRC has classified accident scenarios in dry storage facility and estimated the probability of accidents for each. KAERI and KINS selected major accident scenarios and analyzed the processes for each, in preparation for the introduction of dry storage facility in Korea in the future. Overall, a total of 10 accident scenarios were considered, and the scenarios considered by each institution were different. Among 10 scenarios, cask drop and aircraft collision were included in the categorization of most institutions. The results of this study can be used as basic data for cataloging accidents subject to safety evaluation when introducing dry interim storage facility in Korea in the future.

벚나무류 수목은 생활권 수목(도시공원, 가로수 등)으로 전국에서 가장 많이 식재되고 있으며 전라 남도 또한 벚나무류 수목이 가로수 중 가장 많은 비율을 차지하고 있다. 복숭아유리나방은 농업환경 외에도 생활권 녹지공간에서도 벚나무류 수목을 가해하여 피해를 발생시키고 있는 것으로 보고되고 있으나, 생활권 수목과 산림에서의 관련 연구는 그 필요성에 비해 미흡한 상황이다. 본 연구는 전라남 도 내 생활권 수목을 기주로 하여 발생하는 복숭아유리나방의 발생소장을 조사하여 생활권 녹지공간 을 관리하는 기초자치단체들의 효용성 있는 방제 전략 수립에 기여하고자 한다. 복숭아유리나방의 발생 확인을 위해 육안 확인이 용이한 피해흔을 세 가지로 분류하였으며, 성페로몬 루어와 트랩으로 복숭아유리나방 성체를 유인･채집하였다. 그 결과, 4월 중순 첫 우화를 확인하였으며, 5월 중순과 8월 중순에 2번의 우화 최성기를 확인하여 이때의 유효적산온도를 조사하였다. 또한, 채집된 개체들 의 종 확인 및 유전적 다양성 확인을 위해 mitochondrial 내 cytochrome oxidase subunit I (COI) 유전자 염기 서열의 분석을 수행하였다.

지난 2022년 제주도 애월읍 일대에서 콩 해충으로 알려진 콩은무늬밤나방(Ctenoplusia agnata) 성충이 검거세 미밤나방(Agrotis ipsilon)의 성페로몬 트랩에 대량으로 포획되었다. 검거세미밤나방 트랩은 목적 해충에 대한 포획 효율을 조사하기 위해 세 구성 성분, (Z)-7-dodecenyl acetate, (Z)-9-tetradecenyl acetate를 3:1 비율로 고정하고 (Z)-11-hexadecenyl acetate를 0, 1, 6, 10, 15로 각각 비율을 달리한 미끼를 사용하였다. 각 조성별 콩은무늬밤나방 성충 포획수를 비교한 결과, (Z)-11-hexadecenyl acetate가 첨가되지 않은 트랩에서 주당 평균 약 17.96마리로, 가장 많은 수의 개체가 포획된 것으로 확인되었다. 반면, (Z)-11-hexadecenyl acetate가 가장 많이 함유된 트랩에서 주당 평균 약 2.5마리로 가장 적은 개체가 포획된 것으로 파악되었다. 이에 (Z)-11-hexadecenyl acetate의 비율이 증가할 수록, 포획되는 콩은무늬밤나방의 개체 수가 감소되는 것을 확인할 수 있었다. 검거세미밤나방 미끼의 주성분인 Z)-7-dodecenyl acetate는 기존의 콩은무늬밤나방 유인 성분 중 하나이기도 하여 해당 성분의 구성비가 유인에 영향을 미쳤다는 것을 예측할 수 있다. 추후에 해당 트랩들과 시판 중인 콩은무늬밤나방 성페로몬 트랩을 설치하 여 포획 양상을 비교할 필요성이 요구된다.

Bombyx mandarina (Lepidoptera: Bombycidae), the presumed ancestor of B. mori, has long been a subject of study to illustrate the geographic relationships in connection with origin of B. mori. We report 97 mitochondrial genome (mitogenome) sequences of B. mandarina collected from Korea and Japan. Phylogenetic and population genetic analyses showed that all individuals of B. mandarina collected in Korean localities formed a strong group together with all individuals originated from northern China (mainly north of the Qinling-Huaihe line) and some of southern China. This group was placed as the sister group to B. mori strians suggesting that this group had been served as an immediate progenitor for B. mori.

This study was aimed to isolate bacterial inoculants producing chitinase and evaluate their application effects on corn silage. Four corn silages were collected from four beef cattle farms to serve as the sources of bacterial inoculants. All isolates were tested against Fusarium graminearum head blight fungus MHGNU F132 to confirm their antifungal effects. The enzyme activities (carboxylesterase and chitinase) were also measured to isolate the bacterial inoculant. Based on the activities of anti-head blight fungus, carboxylesterase, and chitinase, L. buchneri L11-1 and L. paracasei L9-3 were subjected to silage production. Corn forage (cv. Gwangpyeongok) was ensiled into a 10 L mini silo (5 kg) in quadruplication for 90 days. A 2 × 2 factorial design consists of F. graminearum contamination at 1.0104 cfu/g (UCT (no contamination) vs. CT (contamination)) and inoculant application at 2.1 × 105 cfu/g (CON (no inoculant) vs. INO (inoculant)) used in this study. After 90 days of ensiling, the contents of CP, NDF, and ADF increased (p<0.05) by F. graminearum contamination, while IVDMD, acetate, and aerobic stability decreased (p<0.05). Meanwhile, aerobic stability decreased (p<0.05) by inoculant application. There were interaction effects (p<0.05) on IVNDFD, NH3-N, LAB, and yeast, which were highest in UCT-INO, UCT-CON, CT-INO, and CT-CON & INO, respectively. In conclusion, this study found that mold contamination could negatively impact silage quality, but isolated inoculants had limited effects on IVNDFD and yeast.

As nuclear power plants are operated in Korea, low and intermediate-level radioactive wastes and spent nuclear fuels are continuously generated. Due to the increase in the amount of radioactive waste generated, the demand for transportation of radioactive wastes in Korea is increasing. This can have radiological effect for public and worker, risk assessment for radioactive waste transportation should be preceded. Especially, if the radionuclides release in the ocean because of ship sinking accident, it can cause internal exposure by ingestion of aquatic foods. Thus, it is necessary to analyze process of internal exposure due to ingestion. The object of this study is to analyze internal exposure by ingestion of aquatic foods. In this study, we analyzed the process and the evaluation methodology of internal exposure caused by aquatic foods ingestion in MARINRAD, a risk assessment code for marine transport sinking accidents developed by the Sandia National Laboratory (SNL). To calculate the ingestion internal exposure dose, the ingestion concentrations of radionuclides caused by the food chain are calculated first. For this purpose, MARINRAD divide the food chain into three stages; prey, primary predator, and secondary predator. Marine species in each food chain are not specific but general to accommodate a wide variety of global consumer groups. The ingestion concentrations of radionuclides are expressed as an ingestion concentration factors. In the case of prey, the ingestion concentration factors apply the value derived from biological experiments. The predator's ingestion concentration factors are calculated by considering factors such as fraction of nuclide absorbed in gut, ingestion rate, etc. When calculating the ingestion internal exposure dose, the previously calculated ingestion concentration factor, consumption of aquatic food, and dose conversion factor for ingestion are considered. MARINRAD assume that humans consume all marine species presented in the food chain. Marine species consumption is assumed approximate and conservative values for generality. In the internal exposure evaluation by aquatic foods ingestion in this study, the ingestion concetration factor considering the food chain, the fraction of nuclide absorbed in predator’s gut, ingestion rate of predator, etc. were considered as influencing factors. In order to evaluate the risk of maritime transportation reflecting domestic characteristics, factors such as domestic food chains and ingestion rate should be considered. The result of this study can be used as basis for risk assessment for maritime transportation in Korea.

Kori unit 1, the first PWR (Pressurized Water Reactor) in Korea, was permanent shut down in 2017. In Korea, according to the Nuclear Safety Act, the FDP (Final Decommissioning Plan) must be submitted within 5 years of permanent shutdown. According to NSSC Notice, the types, volumes, and radioactivity of solid radioactive wastes should be included in FDP chapter 9, Radioactive Waste Management, Therefore, in this study, the types depending on generation characteristics and radiological characterization methods and process of solid radioactive waste were analyzed. Solid radioactive waste depending on the characteristics of the generation was classified into reactor vessel and reactor vessel internal, large components, small metals, spent nuclear fuel storage racks, insulation, wires, concrete debris, scattering concrete, asbestos, mixed waste, soil, spent resins and filters, and dry active waste. Radiological characterization of solid radioactive waste is performed to determine the characteristics of radioactive contamination, including the type and concentration of radionuclides. It is necessary to ensure the representativeness of the sample for the structures, systems and components to be evaluated and to apply appropriate evaluation methods and procedures according to the structure, material and type of contamination. Therefore, the radiological characterization is divided into concrete and structures, systems and components, and reactor vessel, reactor vessel internal and bioshield concrete. In this study, the types depending on generation characteristics and radiological characterization methods and process of solid radioactive waste were analyzed. The results of this study can be used as a basis for the preparation of the FDP for the Kori unit 1.

Wolsong unit 1, the first PHWR (Pressurized Heavy Water Reactor) in Korea, was permanent shut down in 2019. In Korea, according to the Nuclear Safety Act, the FDP (Final Decommissioning Plan) must be submitted within 5 years of permanent shutdown. According to NSSC Notice, the types, volumes, and radioactivity of solid radioactive wastes should be included in FDP chapter 9, Radioactive Waste Management, Therefore, in this study, activation assessment and waste classification of the End shield, which is a major activation component, were conducted. MCNP and ORIGEN-S computer codes were used for the activation assessment of the End shield. Radioactive waste levels were classified according to the cooling period of 0 to 20 years in consideration of the actual start of decommissioning. The End shield consists of Lattice tube, Shielding ball, Sleeve insert, Calandria tube shielding sleeve, and Embedment Ring. Among the components composed for each fuel channel, the neutron flux was calculated for the components whose level was not predicted by preliminary activation assessment, by dividing them into three channel regions: central channel, inter channel, and outer channel. In the case of the shielding ball, the neutron flux was calculated in the area up to 10 cm close to the core and other parts to check the decrease in neutron flux with the distance from the core. The neutron flux calculations showed that the highest neutron flux was calculated at the Sleeve insert, the component closest to the fuel channel. It was found that the neutron flux decreased by about 1/10 to 1/20 as the distance from the core increased by 20 cm. The outer channel was found to have about 30% of the neutron flux of the center channel. It was found that no change in radioactive waste level due to decay occurred during the 0 to 20 years cooling period. In this study, activation assessment and waste classification of End Shield in Wolsong unit 1 was conducted. The results of this study can be used as a basis for the preparation of the FDP for the Wolsong unit 1.

In Korea, the construction of dry storage facilities for spent nuclear fuel is being promoted through the 2nd basic plan for high-level radioactive waste management. When operating dry storage facilities, exposure dose assessment for workers should be performed, and for this, exposure scenarios based on work procedures should be derived prior. However, the dry storage method has not yet been sufficiently established in Korea, so the work procedure has not been established. Therefore, research is needed to apply it domestically based on the analysis of spent nuclear fuel management methods in major overseas leading countries. In this study, the procedure for receiving and storing spent nuclear fuel in a concrete overpack-based storage facility was analyzed. Among the various spent nuclear fuel management systems, the metal overpack-based HI-STAR 100 system and the concrete overpackbased HI-STORM 100 system are quite common methods in the United States. Therefore, in this study, work procedures were analyzed based on each final safety analysis report. First, the HI-STAR 100 overpack enters the facility and is placed in the transfer area. Remove the impact limiter of the overpack and install the alignment device on the top of the overpack. Place the HI-TRAC, an on-site transfer device, on top of the alignment unit and remove the lids of the two devices to insert the canister into the HI-TRAC. When the canister transfer is complete, reseat the lid to seal it, and disconnect the HI-TRAC from the HI-STAR 100. Raise the canister-loaded HI-TRAC over the alignment device on the top of the HI-STORM 100 overpack and remove the lids of the two devices that are in contact. Insert the canister into the HI-STORM 100 and reseat the lid. The HI-STORM 100 loaded with spent nuclear fuel is transferred to the designated storage area. In this study, the procedure for receiving and storing spent nuclear fuel in a concrete overpack-based storage facility was analyzed. The main procedure was the transfer of canisters between overpacks, and it was confirmed that HI-TRAC was used in the work procedure. The results of this study can be used as basic data for evaluating the exposure dose of operating workers for the construction of dry storage facilities in Korea.