Pythium ultimum에 의한 묘립고병에 감수성인 완두품종의 종자는 저항성품종의 종자보다 다량의 환원당이 종자분필물내에 포함되었으며 분필속도도 감수성인 완두품종의 종자에서 더 빨랐다. 묘립고병에 저항성인 완두품종의 종자와 감수성인 품종의 종자분필물에서 모두 Raffinose, Meilbiose, Sucrose, Glucose 및 Fructose가 확인되었으나 Glucose와 Sucrose는 감수성 품종의 종자분필물에서 더 많이 검출되었다. Pythium ultimum균은 감수성인 종자 및 종자분필물에서 더 잘 자랐다.

벼를 가해하는 4종의 멸구매미충 즉 애멸구, 끝동 매미충, 벼멸구 및 흰등멸구의 경제적 중요성에 대한 지역적 차이를 수원과 남부 그리고 남서 해안지역에서 수행한 개체군의 밀도조사를 토대로 분석 검토하였다. 한국에서 년중 볼 수 있는 애멸구와 끝동 매미충의 경제적 중요성은 중부지방이 덜한 것으로 보인다. 이는 겨울의 추운 기후조건, 벼, 보리의 경작 방법 및 거미류 같은 천직에 의해서 지연 치사작용이 효과적으로 일어나는 때문인 것으로 믿어진바. 그러나 남부지방에서는 겨울이 덜 춥고 벼, 보리의 경작방법이 이 두 해충의 생활환과 기주식물의 계절적 변천 양자의 재일성에 유리한 편이어서 이들의 경제적 중요성은 확실히 크다고 하겠다. 한국에서 원동을 하지 못하는 벼멸구와 흰등멸구의 매년 첫 발생개체군은 동지나해를 건너 원거리를 이동해 오는 것들에 기인된다. 이들의 이동과 관련을 갖고 있는 기상요소로 해서 이동되어오는 벼멸구와 흰등멸구의 양은 중부지방보다 남부지방에서 월등히 많다. 그러므로 벼를 가해하는 멸구매미충류에 대한 종합방제책으로 중부와 남부지방 별로 지침을 달리 세울 것이 요망된다.

방사선을 이용한 도열병연구의 기초자료로서 도열병균의 포자와 발아균계에 각각 X-ray 10, 40, 80, 120kR를 조사시켜 그들의 방사선감수성 및 생존율을 조사한 결과는 다음과 같다. 1. 도열병균의 포자발아율은 X-ray 소사선량의 증가에 반비례하여 감소되었으며 120kR에서는 거의 생존하지 못하였다. 2. 비교적 저선량인 10kR 조사에서는 초기발아관신장의 촉진 현상을 보였으며 선량의 증가에 따라 균계의 사멸 현상이 현저하였다. 3. X-ray 조사에 의한 발아균계의 생존율 및 신장은 선량의 증가에 반비례하여 감소하였다. 4. X-ray를 조사받은 발아균계는 포자에 비하여 높은 방사선 감수성을 보였으며, 고선량일수록 그 차이는 현저하였다. 5. X-ray 조사에 의한 도열병균의 돌연변이율은 조사선량에 정비례하여 증가하였다.

통일품종이 가지는 도열병 저항성의 요인을 구명하기 위하여 수도체내에 함유하는 질소, 규산 및 Flavonoid함량을 분석하고 시비수준을 달리하여 재배한 풍광에서 이들 성분함량이 도열병 발병율에 미치는 영향을 조사하였다. 1. 수도체내 규산과 Flavonoid 함량은 질소 시비량과 반비례하고 규산 시비량과는 정비례하여 증가하였다. 2. 도열병 상습답에서의 도열병 발병율은 체내 질소함량에 정비례하고 규산함량에 반비례하였다. 3. 도열병에 대하여 저항성인 통일에서는 저항성의 요인이 되는 규산 및 Flavonoid의 체내함량이 이병성인 풍광에 비하여 현저히 높았다. 4. 규화세포의 수는 고엽일수록 많고 생육의 진전에 따라 증가하였으며 풍광에서 보다는 통일에서 현저히 높았다. 5. 이들 체내 성분의 함량은 통일이 갖는 도열병 저항성의 한 요인인 것으로 보였다.

새로운 수도품종통일에 발생하는 갈색엽고병 유사증상을 발견하여 그 병반에서 병원균을 분리하여 그 형태를 조사하였으며 분생포자, 병반상에 형성하는 자남, 자남포자의 기재를 타연구자를의 문헌과 비교한 결과, 이는 일본에서도 보고된 바 있는 갈색엽고병임이 확인되었으며 병원균이 Fusarium nivale로 동정되었다. 또한 포장조건하에서는 본병은 다질소구에서 그 발생이 현저히 많았음을 관찰하였고, 본균의 생육적온은 였다.

Uranium-contaminated soil can be effectively decontaminated through acid leaching; however, this process process generates significant amounts of radioactive wastewater. Therefore, developing efficient methods to remove uranium from wastewater is essential to minimize radioactive waste generation. This study investigates the applicability of various precipitation methods for uranium removal from acidic wastewater produced during soil-washing processes. Three methods were evaluated: metal hydroxide (M–OHx) co-precipitation, uranium peroxide (UO4) precipitation, and uranium phosphate (KUO2PO4) precipitation. The M–OHx precipitation method removes uranium by precipitating excess metal ions in wastewater by adjusting the pH. This method is easy to use and has a high removal efficiency. The UO4 and KUO2PO4 precipitation methods involve adding reagents to precipitate uranium in the mineral phase. They enable selective uranium separation and further volume reduction. In the results, M–OHx and KUO2PO4 precipitation methods remove uranium to less than 1 mg∙L−1 within 2 h, demonstrating superior capabilities compared to UO4 precipitation. The optimal method is different depended on the management strategy for the recovered uranium. The M–OHx precipitation method was suitable for permanent disposal, whereas KUO2PO4 could be recycled. Based on these findings, guidelines for the effective treatment of wastewater containing uranium from the soil-washing process can be established.

Uranium-contaminated soil can be cleaned using an acid washing process. However, high-concentration acid washing generates substantial amounts of radioactive waste, making it essential to develop a treatment process using low-concentration acid. This study evaluated the effectiveness of low-concentration sulfuric acid washing for uranium removal from contaminated soil. Experiments were conducted with a 0.05 M sulfuric acid solution. With a mixing ratio of soil to acid solution at 1:5, three consecutive washes were sufficient to remove uranium from contaminated soil to clearance level. During the acid washing process, real-time pH monitoring was performed to analyze the correlation between uranium leaching and pH changes. This led to the establishment of a monitoring-based process control strategy. In conclusion, we identified an effective method for removing uranium from soil under low acid concentration conditions. Consequently, significant reductions in radioactive waste generation are anticipated.

Acid-washed solutions containing various ions, including uranium, are produced by washing uranium-bearing soil or minerals with H2SO4. Conventional extraction processes are complex, as they involve multiple steps and generate significant amounts of radioactive organic waste, posing environmental risks. Therefore, it is necessary to develop a simplified process that can selectively extract uranium while minimizing radioactive waste production. In this study, thermodynamic equilibrium calculations were performed to investigate the selective extraction of uranium through its reaction with H2O2. A basic additive was introduced to facilitate this reaction. The calculation results indicated that uranium in acid-leached solutions could be selectively extracted through a single-step precipitation process, which was experimentally validated. These findings can be utilized to design an efficient process for obtaining high-purity uranium from uranium-bearing soil or minerals.

The increase in radioactive waste increased the demand for transportation to the disposal facility. Prior to transporting radioactive waste, confirming that the potential exposure is insignificant is crucial. Overland transportation risk assessment models were developed tailored to domestic characteristics. Dose assessment using this model requires selecting appropriate factors. However, users may struggle to derive appropriate values, leading to inaccuracies. Additionally, if assessment results show outliers, prioritizing factors for review can be challenging. Therefore, sensitivity analysis is necessary to prioritize factors for accurate assessment. In this study, sensitivity analysis was conducted on the on-link public risk assessment model factors for radioactive waste overland transportation. Initially, assessment models were analyzed by each detailed exposure scenario. Subsequently, uncertainty propagation-based sensitivity analysis methodology was applied. The default values for the assessment model factors were set, and sensitivity analysis was conducted based on road type for maximum individual and collective dose assessment models. For the maximum individual dose model, the distance to the samedirection vehicle was the most sensitive, whereas for the collective dose model, vehicle velocity was the most sensitive. The results of this study can be used as the basic data on radioactive waste transportation risk assessment in Korea in the future.

A scintillator using organic materials can be easily manufactured in various shapes and sizes to suit the user’s purpose. A quantum dot (QD)-based scintillator has a number of advantages over commercial scintillators, including emission wavelength control, high-purity emission of a specific wavelength, high photoluminescence efficiency, and good photostability. The organic scintillators doping with various agents into the polymer media to increase scintillation efficiency and to control the emissioning wavelength through energy transfer process. In this study, scintillator enhancement was observed with different QDs material and detection response to gamma and neutron was investigated in energy spectrum. Multishell- structure QDs (CdS/CdZnS/ZnS) were fabricated and utilized to offset the shortcomings of single-shell-structure QDs, and the optical properties and the gamma and neutron detection performance capabilities were evaluated. The results of the evaluation of the detection response of the QD-based scintillator confirmed that the neutron/gamma classification performance was similar to that of a commercial scintillator. Furthermore, the gamma detection efficiency was improved by 34–38% (in the case of 137Cs) compared to a commercial scintillator. This study is especially notable in that the organic scintillator incorporated with the newly fabricated QDs can be utilized for gamma and neutron detection for the operation and decommissioning various nuclear facilities.

Industries that use or produce radionuclides have unintentionally released these substances into surrounding soils and sediments. To address this problem, Beautiful Environmental Construction (BEC) Co. developed the BEC’s Radioactive Soil Decontamination (BERAD) system to remove contaminants and reduce the volume of radionuclide-contaminated soils. Owing to the limited availability of radioactive isotopes such as 60Co, 90Sr, 137Cs, and uranium-contaminated soil, naturally occurring elements in soil were used in this demonstration. The soil was divided into six size fractions via manual wet sieving and the BERAD system. Then, the concentrations of uranium, cobalt, strontium, cesium, and iron in each fraction were measured. The results of both separations showed that a considerable amount of each element is retained in the finer size fractions (<0.2 mm). After BERAD separation, the corresponding values yielded 53% uranium, 45% strontium, 66% cobalt, and 53% cesium in the fine size (<0.2 mm) fractions of 35% by weight. The study found that the concentrations of these elements increased as the particle sizes decreased. Iron and micaceous minerals played a significant role in retaining the elements. The pilot scale BERAD system yielded results that were similar to those obtained via laboratory wet-sieving and was successfully demonstrated as a soil washing technology.

The spent nuclear fuel, combusted and released in the nuclear power plant, is stored in the spent fuel pool (SFP) located in the fuel buildings interconnected with the reactors. In Korea, spent fuel has been stored exclusively in SFPs, prompting initiatives to expand storage capacity by either installing additional SFPs or replacing them with high-density spent fuel storage racks. The installation of these fuel racks necessitates obtaining a regulatory license contingent upon ensuring safe fuel handling and storage systems. Regulatory agencies mandate the formulation of various postulated accident scenarios and assessments covering criticality, shielding, thermal behavior, and structural integrity to ensure safe fuel handling and storage systems. This study describes an evaluation method for assessing the structural damage to storage racks resulting from fuel dropping as a part of the functional safety evaluation of these racks. A scenario was envisaged wherein fuel was dropped onto the base plates of the upper and lower sections of the storage racks, and the impact load was analyzed using the ABAQUS/Explicit program. The evaluation results revealed localized plastic deformation but affirmed the structural integrity and safety of the storage racks.

Because most spent nuclear fuel storage casks have been designed for low burnup fuel, a safety-significant high burnup dry storage cask must be developed for nuclear facilities in Korea to store the increasing high burnup and damaged fuels. More than 20% of fuels generated by PWRs comprise high burnup fuels. This study conducted a structural safety evaluation of the preliminary designs for a high burnup storage cask with 21 spent nuclear fuels and evaluated feasible loading conditions under normal, off-normal, and accident conditions. Two types of metal and concrete storage casks were used in the evaluation. Structural integrity was assessed by comparing load combinations and stress intensity limits under each condition. Evaluation results showed that the storage cask had secured structural integrity as it satisfied the stress intensity limit under normal, off-normal, and accident conditions. These results can be used as baseline data for the detailed design of high burnup storage casks.

To non-destructively determine the burnup of a spent nuclear fuel assembly, it is essential to analyze the nuclear isotopes present in the assembly and detect the neutrons and gamma rays emitted from these isotopes. Specifically, gamma-ray measurement methods can utilize a single radiation measurement value of 137Cs or measure based on the energy peak ratio of Cs isotopes such as 134Cs/137Cs and 154Eu/137Cs. In this study, we validated the extent to which the results of gamma-ray measurements using cadmium zinc telluride (CZT) sensors based on 137Cs could be accurately simulated by implementing identical conditions on MCNP. To simulate measurement scenarios using a lead collimator, we propose equations that represent radiation behavior that reaches the detector by assuming “Direct hit” and “Penetration with attenuation” situations. The results obtained from MCNP confirmed an increase in measurement efficiency by 0.47 times when using the CZT detector, demonstrating the efficacy of the measurement system.