The radiological characterization of SSCs (Structure, Systems and Components) plays one of the most important role for the decommissioning of KORI Unit-1 during the preparation periods. Generally, a regulatory body and laws relating to the decommissioning focus on the separation and appropriate disposal or storage of radiological waste including ILW (intermediate level waste), LLW (low level waste), VLLW (very low level waste) and CW (clearance waste), aligned with their contamination characteristics. The result of the preliminary radiological characterization of KORI Unit-1 indicated that, apart from neutron activated the RV (reactor vessel), RVI (reactor vessel internals), and BS (biological shielding concrete), the majorities of contamination were sorted to be less than LLW. Radiological contamination can be evaluated into two methods. Due to the difficulties of directly measuring contamination on the interior surfaces of the pipe, called CRUD, the assessment was implemented by modeling method, that is measuring contamination on the exterior surfaces of the pipes and calculating relative factors such as thickness and size. This indirect method may be affected by the surrounding radiation distribution, and only a few gamma nuclides can be measured. Therefore, it has limitation in terms of providing detailed nuclide information. Especially, α and β nuclides can only be estimated roughly by scaling factors, comparing their relative ratios with the existing gamma results. To overcome the limitation of indirect measurement, a destructive sampling method has been employed to assess the contamination of the systems and component. Samples are physically taken some parts of the systems or components and subsequently analyzed in the laboratory to evaluate detailed nuclides and total contamination. For the characterization of KORI Unit-1, we conducted the radiation measurement on the exterior surfaces of components using portable instruments (Eberline E-600 SPA3, Thermo G20-10, Thermo G10, Thermo FH40TG) at BR (boron recycle system) and SP (containment spray system) in primary system. Based on these results, the ProUCL program was employed to determine the destructive sample collection quantities based on statistical approach. The total of 5 and 8 destructive sample quantities were decided by program and successfully collected from the BR and SP systems, respectively. Samples were moved to laboratory and analyzed for the detail nuclide characteristics. The outcomes of this study are expected to serve as valuable information for estimating the types and quantities of radiological waste generated by decommissioning of KORI Unit-1.

Domestic commercial low- and intermediate-level radioactive waste storage containers are manufactured using 1.2 mm thick cold-rolled steel sheets, and the outer surface is coated with a thin layer of primer of 10~36 μm. However, the outer surface of the primer of the container may be damaged due to physical friction, such as acceleration, resonance, and vibration during transportation. As a result, exposed steel surfaces undergo accelerated corrosion, reducing the overall durability of the container. The integrity of storage containers is directly related to the safety of workers. Therefore, the development of storage containers with enhanced durability is necessary. This paper provides an analysis of mechanical properties related to the durability of WC (tungsten carbide)-based coating materials for developing low- and intermediate-level radioactive waste storage containers. Three different WC-based coating specimens with varied composition ratios were prepared using HVOF (high-velocity oxy-fuel) technique. These different specimens (namely WC-85, WC-73, and WC-66) were uniformly deposited on cold-rolled steel surfaces ensuring a constant thickness of 250 μm. In this work, the mechanical properties of the three different WCbased coaitng materials evaluated from the viewpoints of microstructure, hardness, adheision force between substrate and coating material, and wear resistance. The cross-sectional SEM-EDS (Scanning Electron Microscope-Energy Dispersive X-ray Spectroscopy) images revealed that elements W (tungsten), C (carbon), Ni (nickel), and Cr (chromium) were uniformly distributed within the each coating layers which was approximately 250 μm thick. The average hardness values of HWC-85 and HWC-73 were found to be 1,091 Hv (Vickers Hardness) and 1,083 Hv, respectively, while the HWC-66 exhibited relatively lower hardness value of 883 Hv. This indicates that a higher WC content results in increased hardness. Adhesion force between and substrates and coating materials exceeded 60 MPa for all specimens, however, there were no significant differences observed based on the tungsten carbide content. Furthermore, a taber-type abrasion tester was used for conducting abrasion resistance tests under specific conditions including an H-18 load weight at 1,000 g with rotational speed set at 60 RPM. The abrasion resistance tests were performed under ambient temperatures (RT: 23±2°C) as well as relative humidity levels (RH: 50±10%). Currently, the ongoing abrasion resistance tests will include some results in this study.

This study focuses on the development of coatings designed for storage containers used in the management of radioactive waste. The primary objective is to enhance the shielding performance of these containers against either gamma or neutron radiation. Shielding against these types of radiation is essential to ensure the safety of personnel and the environment. In this study, tungsten and boron cabide coating specimens were manufactured using the HVOF (High-Velocity Oxy Fuel) technuqe. These coatings act as an additional layer of protection for the storage containers, effectively absorbing and attenuating gamma and neutron radiation. The fabricated tungsten and boron carbide coating specimens were evaluated using two different testing methods. The first experiment evaluates the effectiveness of a radiation shielding coating on cold-rolled steel surfaces, achieved by applying a mixture of WC (Tungsten Carbide) powders. WC-based coating specimens, featuring different ratios, were prepared and preliminarily assessed for their radiation shielding capabilities. In the gamma-ray shielding test, Cs-137 was utilized as the radiation source. The coating thickness remained constant at 250 μm. Based on the test results, the attenuation ratio and shielding rate for each coated specimen were calculated. It was observed that the gammaray shielding rate exhibited relatively higher shielding performance as the WC content increased. This observation aligns with our findings from the gamma-ray shielding test and underscores the potential benefits of increasing the tungsten content in the coating. In the second experiment, a neutron shielding material was created by applying a 100 μm-thick layer of B4C (Boron Carbide) onto 316SS. The thermal neutron (AmBe) shielding test results demonstrated an approximate shielding rate of 27%. The thermal neutron shielding rate was confirmed to exceed 99.9% in the 1.5 cm thick SiC+B4C bulk plate. This indicates a significant reduction in required volume. This study establishes that these coatings enhance the gamma-ray and neutron shielding effectiveness of storage containers designed for managing radioactive waste. In the future, we plan to conduct a comparative evaluation of the radiation shielding properties to optimize the coating conditions and ensure optimal shielding effectiveness.

본 연구는 주변 환경의 차이에 따른 화분매개곤충의 유입 특성을 파악하기 위하여 국립수목원 내 진화속을걷 는정원과 부추속전문전시원에 식재된 울릉산마늘의 화분매개곤충을 조사하였다. 2023년 5월 22일부터 6월 2일 까지 꽃이 70% 이상 개화하였을 때 포충망을 활용하여 8일간 곤충을 채집하였고, 각 전시원 별 식생(피도), 기후 (온도·습도·조도)를 조사하였다. 조사 결과 진화속을걷는정원에서 피도 60% 온도 26.4℃, 습도 31.5%, 조도 40953.6lx, 화분매개곤충 20과 450개체, 부추속전문전시원은 피도 90%, 온도 25.6℃, 습도 31.6%, 조도 6387lx, 화분매개곤충 15과 196개체로 나타났다. 온도와 조도가 상대적으로 높은 진화속을걷는정원이 채집된 곤충의 다양성과 방문 빈도가 높았다. 시간대별 곤충의 방문 빈도를 비교해본 결과 온도와 조도는 개체수가 증가할 때 같이 증가하는 경향을 보였으며, 습도는 반대의 경향을 보였다.

왕담배나방은 기주범위가 넓은 다식성으로 토마토, 옥수수, 담배, 해바라기, 땅콩, 면화, 콩 등 다양한 작물에 피해를 주는 해충이며, 장거리 이동성 해충으로도 유명하다. 본 연구에서는 기존 자료를 바탕으로 월동번데기의 성충으로 우화모델(2종)를 작성하고 포장 실측자료와 비교하여 평가하였다. 월동 번데기는 휴면을 종료한 후 안점소실 과정을 거쳐 정상의 번데기로 이행되고 비로소 성충으로 우화하는 것으로 가정하였다. 첫 번째 모형(모 형 1)은 2단계 휴면후발육 우화모형으로 안점소실에 필요한 적산온도 59.9DD (발육영점온도 15.9℃)와 번데기 발육완료에 필요한 192.3DD (발육영점온도 10.2℃)로 구성하였다. 두 번째 모형(모형 2)은 온도자극 우화모형으 로 17.63℃의 온도자극 이후에 번데기 발육을 개시하는 모형이었다. 적산온도는 단순 평균온도법과 사인곡선법 으로 계산하여 비교하였다. 포장자료와 비교 결과 모형 1에 사인곡선법을 적용했을 때 실측치와 편차가 3일보다 작거나 차이가 없었다. 반면 사인곡선법을 적용한 모형 2는 3~6.5일의 편차가 있었다. 평균온도법을 적용한 경우 두 모형 모두 실측치와 편차가 증가하였다. 모형을 활용하여 예측 우화시기와 트랩유살자료를 비교하여 왕담배 나방의 비래 가능성에 대하여 고찰하였다.

기존에는 생산되는 키틴과 키토산의 대부분이 게, 새우등 갑각류 껍질에서 유래하였다. 하지만 어업에 의존하 는 기존 갑각류 비해 친환경적이며 품질 유지에 이점을 가지는 곤충으로부터 유래한 키틴이 최근 주목 받기 시작 하며 연구가 활발해지고 있다. 이에 키토산이 남조류의 응집을 통해 녹조 제거 효과를 가지며 기존에 녹조를 억제하기 위해 널리 사용되던 살조제들이 독성을 띠어 환경에 악영향을 미치는 문제를 해결할 수 있다는 연구를 참고하여 매미 탈피각으로부터 추출한 키토산을 녹조 방제에 활용해 보고자 하였다. 매미 탈피각으로부터 키토 산을 추출하고 대표적인 녹조 원인종인 Microcystis aeruginosa 배양 후 추출한 키토산을 처리하여 녹조의 응집 효과를 관찰하였다. 본 연구에서 새로운 키토산 추출 원으로서 매미 탈피각의 가능성을 제시하였으며 이를 녹조 방제에 활용함으로써 버려지는 자원인 매미 탈피각의 활용 방안을 제시하였다.

단단한 자구를 가진 적색 비모란선인장 ‘Gangjeok’ 품종 은 ‘Isaek’품종을 모본으로, ‘Suyeon’ 품종을 부본으로 하여 2018년에 교배하여 육성하였다. 교배 후 획득한 종자는 조직 배양실에서 기내파종하여 획득한 유묘를 기내에서 삼각주선 인장에 접목하여 ‘1802001’ 등 20계통을 양성하였다. 2019 년에 기내에서 양성한 20계통을 온실에서 삼각주선인장 대목 에 접목하여 재배하면서 ‘1812005’ 계통을 1차 선발하였다. 2020년부터 2022년까지 3차에 걸쳐서 특성을 검정한 후, 농 산물직무육성품종 심의회에서 최종 선발하여 ‘Gangjeok’으 로 명명하였다.‘Gangjeok’ 품종은 편원형의 적색 구를 가진 다. 혹(tubercle)이 돌출된 형태의 모구는 8.4개의 능(rip)을 가지며, 3.5mm 짧은 회색 가시가 발생한다. 정식 10개월 후 ‘Gangjeok’ 품종의 직경은 46.1mm이며, 자구는 평균 18.3 개 발생한다. 2022년 육성계통 평가회에서 ‘Gangjeok’ 품종 은 높은 기호도 점수 4.0을 받았다.