고압변압기의 1차측을 제어하고 2차측에 유도된 전압을 이용한 수중방전음원의 전기음향학적 제특성을 분석.검사한 결과는 다음과 같다. 1. 방전시 2차측 전류는 초기에는 Ohm 법칙을 따르다가 전류가 최고 6.3A 흘러 절연 파괴되었으며, 그 순간 방전음이 생성되었다. 2. 전류인가점과 방전음 생성문의 시간차는 약 3ms였으며, 전압이 최고일 때 절연파괴가 일어나 방전음이 생성되었다. 3. 전극의 끝이 뾰족할수록 2차측 전압이 높을수록 음압수준은 높았다. 4. 뾰족한 형태의 전극은 전극간격이 100cm일 때도 방전이 일어났으며 전극간격이 1cm이상부터 비교적 안정된 방전음이 생성되었다. 5. 방전음의 펄스폭은 약 0.15ms인 Shock Wave였으며, 10HKz 이하의 합성저주파 성분이었다.

Making use of a relation proposed by Wielen (1977), a new empirical relation between Call emission flux and stellar age is derived by analyzing Wilson and Woolley's spectroscopic data (1970) of late type main sequence stars (K0-M5) and kinematic properties of those stars given by Gliese (1969). The proposed relation shows that the emission flux excess of the Call H-K lines, F ′ k + F ′ k introduced by Linsky et al. (1979) decreases with stellar age τ as τ − 0.51 , consistent with the inverse square law as noted by Skumanich (1972).

배나무 붉은별무늬병은 1973년이래 해마다 발병이 증가하여 1975연에는 발병엽율 에 달하였으며 1974년 향나무 재식규제조치이후 감소하였다. 붉은별무늬병원균의 동포자발아 시기는 4월중순부터 5월중순까지 였으며 인공강우에 의하여 그 발아시기를 5일 전에 알 수 있었다. 성숙한 동포자퇴의 포자발아에는 3시간 이상의 계속되는 비로서 상당량의 강수가 필요하였다. 배나무의 감염은 강우중이나 강우직후에 이루워지고 있었으며 강양 24시간 이후의 감염은 없었다. 감염후 배나무에서의 잠복기간은 일이었다. 배나무와 향나무사이의 지리가 100m 이내인 경우에는 거의 모든 배나무가 발병하였으나 거리가 멀어짐에 따라 발병율도 감소하였으며 2km 이상에서는 발병이 없었다.

본 시험은 이화명충과 과수의 잎말이류 및 Codling Moth의 Pheromone등 모두 15종의 합성 Pheromone을 도입하여 국내해충의 예찰과 방제에 이용가능한 Pheromone의 선발코자 수행하였다. 이화명충 Pheromone은 미국의 열대생산물연구소에서 합성한 것을 사용하였으며 과수해충의 Pheromone은 Comell 대학과 Zoecon회사에서 공급받았다. 본 시험의 결과는 다음과 같다. 1. 이화명충의 미교미 암컷을 넣은 Trap이 합성 Pheromone을 넣은 Trap보다 숫컷을 유인하는 능력이 컸다. 2. 이화명충의 합성 Pheromone은 설치 후 시간이 경과함에 따라 유인력이 감소하여 발생정점을 잡을 수 없었다. 3. 과수잎말이류 해충중 복숭아순나방이 OFM과 LAW Pheromone에 가장 많이 유인되었다. 4. OBLR, RBLR, SPAR, 그리고 ArcM Pheromone에 수종의 과수잎말이류 나방이 다수 유인되었으나 기타 8종의 Pheromone에는 유인나방의 수가 적었다. 5. 본 시험의 결과로 보아 해충의 발생예찰에 이용가능 할 것으로 생각되는 합성 Phreomone과 이들의 적용해충은 다음과 같다. OFM, LAW: 복숭아순나방 OBLR: 사과무늬잎말이나방 OBLR, RBLR, ArcM: 한국잎말이나방, 검모무늬 잎말이나방, 사과잎말이나방 SPAR, TBM Pyroderces속의 일종

①Connecting Spread를 일정하게 하고 Towing Line의 길이를 변화시킬 때 각 속도에 따른 망고 및 망폭 Towing line의 길이가 길어질수록 망고는 높아지고 망폭은 좁아진다. ② Towing line의 길이를 일정하게 하고 Connecting Spread를 변화시킬 때 망고 및 망폭은 Connecting Spread가 넓어질 수록 망폭은 넓어지나 망고는 거의 변화가 없다.

By way of the practical use of the electrical fishing in salt water, all the data I could collect were carefully compared from the earliest kuehne's studies for protoplasm to the precent kreutzer's for electrotaxis of aquatic animals. The consequences are as follows: All the cold blooded animals are forced to move toward the positive pole in the path of an electrical current flowing from pole to pole which has brought about the possibilities of electrical fishing. This method has been found to be practical in fresh water, but there are some obstacles in utilizing the method in salt water especially because of the large amount of electric power consumed. In order to remedy the large power consumption, an intermittent current or pulsive current which stimulate the fish most effectively has been tested, but a few electrical quantative values in detail as to the current intensity and wave forms or any quantative results of these experiments have been made public. According to kreutzer's theory and the above tests, the synthetic observations lead to the conclusion that: (1) The was form of the pulsive current which gives the fish an electric shock most effectively is an almost right angled triangle with a vertical rise from null and a much slower decay. (2) The pulses are let repeatedly after recovering shock on the fish as following figure to minimize the large amount of electric power consumption, the recovering provides the next shock effectively by Weber-Fechner's law on psychophysics. Though wave head rises highly vertical, the decaying wave trails and the inter-mittence of electric current prevent the large consumption of power. (3) The electrotaxis rate among the school of fish is given by Tauti's formula. r=1/√2π σ∫o A log v/voexp{-1/2(x-xo/σ)2dx Where r is an electrotaxis rate, xo a certain sensibility of fish caused at arbitrary voltage stimulation made electrotaxis, x a mean value of the sensibility of fish at the front of fish school, and A log v/vo a mean value of sensibitity of fish at where the voltage is v by Weber-Fechner's law, where vo is an original voltage, A a constant, and σ a standard deviation. The electrotaxis rates are given as above if we regards the distribution iof electrotaxis rate as normal.

This paper stated the variation of the hydrodynamic resistant coefficient K of hand knitting plane model net which was set perpendicularly to the flow of water. The scale of the model net was determined after Tauti's principle for similarity law and experi nent was conducted for measuring the coefficients about two cases of the nets composed of flat knot (reef knot) and trawlers knot(sheet bent). The scale of the model nets which was used in experiment were 1/10, 1/20, 1/30, 1/40, 1/50, 1/60, 1/70, 1/80, 1/90 and full scale. The result of this experiment in circulating water tank came to the conclusion that; a. The hydrodynamic coefficient of trawler knotted net showed about 0.55 higher than the flat knotted net. b. The value of K coincided approximately with the value estimated by the formulae which H. Miyamoto, M. Nomura and Y. shimozaki calculated from experiment. c. The hydrodynamic coefficient K were not varied when the scale ratio was larger than 1/50, the value of K was increased gradually from 1/60 and suddenly increased at 1/80 and 1/90. Therefore, when we design a model net it is appropriate to restrict the scale ratio to less than 1/50, under the condition that the velocity of the full scale is 1.3 knot in this experiment.

To construct and operate nuclear power plants (NPPs), it is mandatory to submit a radiation environmental impact assessment report in accordance with Article 10 and Article 20 of the Nuclear Safety Act. Additionally, in compliance with Article 136 of the Enforcement Regulations of the same law, KHNP (Korea Hydro & Nuclear Power) annually assesses radiation environmental effects and publishes the results for operating NPPs. Furthermore, since the legalization of emission plans submission in 2015, KHNP has been submitting emission plans for individual NPPs, starting with the Shin-Hanul 1 and 2 units in 2018. These emission plans specify the emission quantities that meet the dose criteria specified by the Nuclear Safety and Security Commission. Before 2002, KHNP used programs developed in the United States, such as GASPAR and LADTAP, for nearby radiation environmental impact assessments. Since then, KHNP has been using K-DOSE60, developed internally. K-DOSE60 incorporates environmental transport analysis models in line with U.S. regulatory guidance Regulatory Guide 1.109 and dose assessment models reflecting ICRP-60 recommendations. K-DOSE60 is a stand-alone program installed on individual user PCs, making it difficult to manage comprehensively when program revisions are needed. Additionally, during the preparation of emission plans and the licensing phase, improvements to KDOSE60’ s dose assessment methodology were identified. Furthermore, in 2022, regulatory guidelines regarding resident dose assessments were revised, leading to additional improvement requirements. Currently, E-DOSE60, being developed by KHNP, is a network-based program allowing for integrated configuration management within the KHNP network. E-DOSE60 is expected to be developed while incorporating the identified improvements from K-DOSE60, in response to emission plan licensing and regulatory guideline revisions. Key improvements include revisions to dose assessment methodologies for H-13 and C-14 following IAEA TRS-472, expansion of dose assessment points, and changes in socio-environmental factors. Furthermore, data such as site meteorological information and releases of radioactive substances in liquid and gaseous forms can be linked through a network, reducing the potential for human errors caused by manual data entry. Ultimately, E-DOSE60 is expected to optimize resident exposure dose assessment and enhance public trust in NPP operation.

As the acceptance criteria for low-intermediate-level radioactive waste cave disposal facilities of Korea Radioactive Waste Agency (KORAD) were revised, the requirements for characterization of whether radioactive waste contains hazardous substances have been strengthened. In addition, As the recent the Nuclear Safety and Security Commission Notice (Regulations on Delivery of Low- Medium-Level Radioactive Waste) scheduled to be revised, the management targets and standards for hazardous substances are scheduled to be specified and detailed. Accordingly, the Korea Atomic Energy Research Institute (KAERI) needs to prepare management methods and procedures for hazardous substances. In particular, in order to characterize the chemical requirements (explosiveness, ignitability, flammability, corrosiveness, and toxicity) contained in radioactive waste, it must be proven through documents or data that each item does not contain hazardous substances, and quality assurance for the overall process must be provided. In order to identify the characteristics of radioactive waste that will continue to be generated in the future, KAERI needs to introduce a management system for hazardous substances in radioactive waste and establish a quality assurance system. Currently, KAERI is thoroughly managing chelates (EDTA, NTA, etc.), but the detailed management procedures for hazardous substances related to chemical requirements in radioactive waste in the radiation management area specified above are insufficient. The KAERI’s Laboratory Safety Information Network has a total periodic regulatory review system in place for the purchase, movement, and disposal of chemical substances for each facility. However, there is no documents or data to prove that the hazardous substances held in the facility are not included in the radioactive waste, and there are no procedures for managing hazardous substances. Therefore, it is necessary to establish procedures for the management of hazardous substances, and we plan to prepare management procedures for hazardous substances so that chemical substances can be managed according to the procedures at each facility during preliminary inspection before receiving radioactive waste. The procedure provides definitions of terms and types of management targets for each characteristic of the chemical requirements specified above (explosiveness, ignition, flammability, corrosiveness, and toxicity). In addition, procedure also contains treatment methods of radioactive waste generated by using hazardous substances and management methods of in/out, quantity, history of that substances, etc. As the law is revised in the future, management will be carried out according to the relevant procedures. In this study, we aim to present the hazardous substance management procedures being established to determine whether radioactive waste contains hazardous substances in accordance with the revised the notice and strengthened acceptance criteria. Through this, we hope to contribute to improving reliability so that radioactive waste could be disposed of thoroughly and safely.

Ion exchange resins are commonly employed in the treatment of liquid radioactive waste generated in nuclear power plants (NPP). The ion exchange resin used in NPP is a mixed-bed ion exchange resin known as IRN-150, which is of nuclear grade. This resin is a mixture of cation exchange resin and anion exchange resin. The cation exchange resin removes cationic radionuclides such as Cs and Co, while anion exchange resin handles anions (e.g., H14CO3 -), effectively purifying the liquid waste. Spent ion exchange resins (spent resin) containing C-14 are classified as low and intermediate level radioactive waste, and their radioactivity needs to be reduced as it exceeds the disposal limit regulated by law. Therefore, the microwave technology for the removal of C-14 from spent resin has been investigated. Previous studies have successfully developed a method for the effective removal of C-14 during the resin treatment process. However, it was observed that, in this process, functional groups in the resin were also removed, resulting in the generation of off-gases containing trimethylamine. These off-gases can dissolve in water from process, increasing its pH, which can subsequently hinder the recovery of C-14. In this study, we investigated the high-purity recovery of C-14 by adjusting the moisture content within the reactor following microwave treatment. Mock spent resins, consisting of 100 g of resin with HCO3 - ion-exchanged and 0, 25, or 50 g of deionized water, were subjected to microwave treatment for 40 or 60 minutes. Subsequently, the C-14 desorption efficiency of the mock spent resins was evaluated using an acid stripping process with H3PO4 solution. The functional group status of the mock spent resins was analyzed using 15N NMR spectroscopy. The results showed that the mock spent resins exhibited efficient C-14 recovery without significant functional group degradation. The highest C-14 desorption efficiency was achieved when 25 g of deionized water was used during microwave treatment.

The increasing accumulation of spent nuclear fuel has raised interest in High-Level Waste (HLW) repositories. For example, Sweden is under construction of the KBS-3 repository. To ensure the safety of such HLW repository, various countries have been developing assessment models. In the Republic of Korea, the Korea Atomic Energy Research Institute has been developing on the AKRS model. However, traditional safety assessment models have not considered the fracture growth in the far-field host rock as a function of time. As repository safety assessments guarantee safety for million years, sustained stress naturally leads to the progressive growth of fractures as time goes on. Therefore, it becomes essential to account for fracture growth in the surrounding host rock. To address this, our study proposes a new coupling scheme between the Fracture growth model and the radionuclide transport model. That coupling scheme consists of the Cubic Law model as a fracture growth function and the GoldSim code which is a commercial software for radionuclide transport calculations. The model that adopting such fracture growth functions showed an increase of up to 15% in the release of radionuclide compared to traditional assessment models. our observations indicated that crack growth as a function of time led to an increase in hydraulic conductivity that allowed more radionuclide transport. Notably, these findings show the significance of adopting fracture growth models as a critical element in evaluating the safety of nuclear waste repositories.

It is crucial to understand the hydro-mechanical behavior of rock mass to assess the performance of natural barriers. As rock fractures serve as both mechanically weak planes and prominent pathways for hydraulic flow, they significantly influence the hydro-mechanical behavior of the rock mass. Hence, understanding the characteristics of rock fractures is necessary to analyze the long-term behavior of natural barriers. In particular, fracture apertures are crucial parameters directly associated with groundwater flow and consequently hold significant importance in determining the hydro-mechanical behavior of natural barriers. Fracture apertures are defined as mechanical and hydraulic apertures, and various studies have been conducted to measure and analyze them. However, direct measurement of mechanical aperture according to changes in normal stress is known to be a challenging task. For this reason, there has been a scarcity of direct comparative findings between mechanical and hydraulic apertures under various normal stress conditions. This study aims to analyze the characteristics of the mechanical and hydraulic apertures according to changes in normal stress based on experimental results. A digital analysis technique using a pressure film image was applied to analyze the mechanical aperture characteristics of the fracture. This technique can be applied by performing a pressure film compression test and a normal stiffness test on a fracture specimen, and has the advantage of being able to derive mechanical apertures under various normal stress conditions. The hydraulic aperture characteristics of the fracture were analyzed based on Cubic law after measuring the flow rate by performing a constant pressure injection test under triaxial compression conditions. By applying various confining pressures, it was possible to examine the hydraulic apertures according to changes in normal stress conditions. Through the experimental results, the relationship between the mechanical and hydraulic apertures of the fracture was summarized under various normal stress conditions. In addition, the experimental results were used to examine the applicability of various empirical equations for mechanical and hydraulic apertures proposed in previous studies. The characteristics of the fracture aperture resulting from this study are significant because they are required in the hydro-mechanical model of natural barriers. Future studies will entail further experiments, with the objective of establishing novel relationships based on the accumulation of experimental data.

The natural barrier system surrounding the geological repository for high-level radioactive waste plays a crucial role in preventing or delaying the leakage of radionuclides. Therefore, the natural barrier should ensure low permeability to prevent groundwater flow into the engineered barrier system throughout the repository’s lifetime. Crystalline rock, considered as the host rock for the geological repository in Korea, exhibits low intact rock permeability, but the crystalline rock often contains the multiple discontinuities due to its high brittleness that can allow the unexpected fluid flow. Therefore, the long-term hydraulic behavior of the discontinuity should be characterized while considering additional thermal, mechanical, and chemical effects. In comparison to thermal, hydraulic, and mechanical processes, the chemical processes on the discontinuities progress relatively slowly, resulting in limited researches to include these chemical processes. This research introduces mechanisms the involving coupled thermal-hydraulic-mechanicalchemical processes focusing on the rough fracture surfaces and asperities. The chemically-induced changes in mechanical and hydraulic properties are described based on pressure solution and precipitation concepts. A comprehensive review of laboratory tests, field tests, and numerical simulations is conducted related to the chemically-induced coupled processes in fractured rock. Laboratory tests, in particular, concentrate on microscopic changes in fracture asperities induced by pressure solution to analyze chemically-induced aperture changes. The TOUGHREACT, an integral finite difference method program for thermal-hydraulic-chemical simulations, is generally employed to model the chemical response of pressure solution and precipitation on fracture surfaces. The TOUGHREACT includes a module to describe effective porosity and permeability changes based on the modified cubic law, so the real-time change of the fracture permeability can be reflected during the flow simulation. Considering the coupled thermal-hydraulic-mechanicalchemical processes of discontinuity, it becomes evident that the chemical processes under repository conditions (long-term, high temperature, and high pressure) can disturb the hydraulic performance of the natural barrier, so further research is required to characterize the chemically-induced coupled processes for assessing the long-term performance of the natural barrier system.

Considering the domestic situation where all nuclear power plants are located on seaside, the interim storage site is also likely to be located on coastal site. Maritime transportation is inevitable and the its risk assessment is very important for safety. Currently, there is no independently developed maritime transportation risk assessment code in Korea, and no research has been conducted to evaluate the release of radioactive waste due to the immersion of transport cask. Previous studies show that the release rate of radionuclides contained in a submerged transport cask is significantly affected by the area of flow path generated at the breached containment boundary. Due to the robustness of a cask, the breach is the most likely generated between the lid and body of cask. CRIEPI investigated the effect of cask containment on the release rate of radioactive contents into the ocean and proposed a procedure to calculate the release rate considering the socalled barrier effect. However, the contribution of O-ring on the release rate was not considered in the work. In this study, test and analysis is performed to determine the equivalent flow path gap considering the influence of O-rings. These results will be implemented in the computational model to assess sea water flow through a breached containment boundary using CFD techniques to assess radionuclide release rates. To evaluate the release rate as a function of lid displacement, a small containment vessel is engineered and a metal O-ring of the Helicoflex HN type is installed, which is the most commonly used one in transport and storage casks. The lid of containment vessel is displaced in vertical and horizontal direction and the release rate of the vessel was quantified using the helium leak test and the pressure drop test. Through this work, the relationship between the vertical opening displacement and horizontal sliding displacement of the cask lid and the actual flow path area created is established. This will be implemented in the CFD model for flow rate calculation from a submerged transport cask in the deep sea. In addition, the compression of the O-ring causes very small gaps, such as capillaries. In these cases, Poiseuille’s law is used to calculate the capillary flow rate.

Once discharged, spent nuclear fuel undergoes an initial cooling process within deactivation pools situated at the reactor site. This cooling step is crucial for reducing the fuel’s temperature. Once the heat has sufficiently diminished, two viable options emerge: reprocessing or interim storage. A method known as PUREX, for aqueous nuclear reprocessing, involves a chemical procedure aimed at separating uranium and plutonium from the spent nuclear fuel. This separation not only minimizes waste volume but also facilitates the reuse of the extracted materials as fuel for nuclear reactors. The transformation of uranium oxides through dissolution in nitric acid followed by drying results in uranium taking the form of UO2(NO3)2 + 6H2O, which can then be converted into various solid-state configurations through different heat treatments. This study specifically focuses on investigating the phase transitions of artificially synthesized UO2(NO3)2 + 6H2O subjected to heat treatment at various temperatures (450, 500, 550, 600°C) using X-ray Diffraction (XRD) analysis. Heat treatments were also conducted on UO2 to analyze its phase transformations. Additionally, the study utilized XRD analysis on an unidentified oxidized uranium oxide, UO2+X, and employed lattice parameters and Bragg’s law to ascertain the oxidation state of the unknown sample. To synthesize UO2(NO3)2 + 6H2O, U3O8 powder is first dissolved in a 20% HNO3 solution. The solid UO2(NO3)2 + 6H2O is obtained after drying on a hotplate and is subsequently subjected to heat treatment at temperatures of 450, 500, 550, and 600°C. As the heat treatment temperature increases, the color of the samples transitions from orange to dark green, indicating the formation of different phases at different temperatures. XRD analysis confirms that uranyl nitrate, when heattreated at 500 and 550°C, oxidizes to UO3, while the sample subjected to 600°C heat treatment transforms into U3O8 due to the higher temperature. All samples exhibit sharp crystal peaks in their XRD spectra, except for the one heat-treated at 450°C. In the second experiment, the XRD spectra of the heat-treated UO2 consistently indicate the presence of U3O8 rather than UO3, regardless of the temperature. Under an oxidizing atmosphere within a temperature range of 300 to 700°C, UO2 can be oxidized to form U3O8. In the final experiment, the oxidation state of the unknown UO2+X was determined using Bragg’s law and lattice parameters, revealing that it was a material in which UO2 had been oxidized, resulting in an oxidation state of UO2.24.

Given the situation in the Republic of Korea that all nuclear power plants are located at the seaside, the interim storage facility is also likely to be located at seaside and the maritime transportation of Spent Nuclear Fuel is considered inevitable. The Republic of Korea does not have an independently developed maritime transportation risk assessment code, and no research has been conducted to evaluate the release rate of radionuclides from a submerged transportation cask in the sea. Therefore, there is a need to develop a technology that can assess the impact of immersion accidents and establish a regulatory framework for maritime transportation accidents. The release rate of radionuclides should be calculated from the flow rate through a flow path in the breached containment boundary. According to the cask design criteria, it is anticipated that even under severe accident conditions, the flow path size will be very small. Previous studies have evaluated fluid flow passing through micro-scale channel by integrating internal and external flows within and around a transport cask. As part of the evaluation, a comprehensive “Full-Field Model” incorporating external flow fields and a localized “Local-Field Model” with micro-scale flow paths were constructed. Sub-modeling techniques were employed to couple the flow field calculated by the two models. The aforementioned approach is utilized to conduct the evaluation of fluid flow passing through micro-scale flow paths. This study aims to evaluate fluid flow passing through micro-scale flow paths using the aforementioned CFD (Computational Fluid Dynamics) method and aims to code the findings. The Gaussian Process Regression technique, a machine learning model, is utilized for developing a mathematical metamodel. The selected input parameters for coding are organized and their respective impacts are analyzed. The range of these selected parameters is tailored to suit domestic environments, and computational experiments are planned through Design of Experiments. The flow path size is included as an input parameter in the coded model. In cases where the flow path size becomes extremely small, making it impractical to use CFD techniques for calculations, Poiseuille’s law is employed to calculate the release rate. In this study, a model is developed to evaluate the release rate of radionuclides using CFD and mathematical equations covering the whole possible range of flow path size in a lost cask in the deep sea. The model will be used in the development of a maritime transportation risk assessment code suitable for the situation and environment in Korea.

When exporting nuclear-related items, export control is required from two perspectives: the control of “Trigger List Items” as controlled by Nuclear Supplier Groups (NSG) and the control of the “Items Subject to the Agreement” as specified in bilateral Nuclear Cooperation Agreements. While Trigger List Items and Items Subject to the Agreement are largely similar, there are some items where they do not overlap. Furthermore, national law for controlling each item is different. The Trigger List Items are governed by the Foreign Trade Act, and the Items Subject to the Agreement (Internationally Controlled Items) are governed by the Nuclear Safety Act. As a result, the detailed procedures and requirements for controlling each item are quite distinct. For the Trigger List Items, export license must be obtained in accordance with the Foreign Trade Act. The details such as responsible authority, the items subject to license, license requirements and procedures, penalties are specified in the Public Notice on Import and Export of Strategic Goods. For the Items Subject to the Agreement, the process and obligations set forth in bilateral agreements and related administrative agreements are fulfilled in accordance with the Nuclear Safety Act. However, in contrast to the Trigger List Items, the details for complying with the agreements are not specified legally. Since most of the Items Subject to the Agreement are fall within the category of the Trigger List Items, the obligations in accordance with the agreements are reviewed and implemented during the export license assessment process. However, if the Items Subject to the Agreement are not are fall within the category of the Trigger List Items, there is a risk of control omission. For example, this applies to cases of exporting tritium and tritium removal facilities, which are not the Trigger List Items, to Canada and Romania. Moreover, since subjects to the agreement and compliance procedures are respectively different for 29 bilateral Nuclear Cooperation Agreements signed with different countries, it is difficult for enterprise to recognize the appropriate procedures and obligations under the agreement by their own. The bilateral Nuclear Cooperation Agreements establish legal obligations between state parties while NSG are non-legally binding arrangements. Therefore, it could be even more necessary to comply strictly with the agreements. Consequently, legal improvements are required for effective implementations of Nuclear Cooperation Agreements. While it may be challenging to institutionalize details of 29 Nuclear Cooperation Agreements, it is essential to legally specify key elements such as the list of items subject to agreements, responsible authority, requirements and procedures for implement the agreement obligations, and penalties. Furthermore, domestic awareness on compliance with Nuclear Cooperation Agreements is lower compared to the system of export license for Trigger List Items. The continuous outreach is also necessary, along with institutional improvements.

The ROK government has developed the Nuclear Export and Control System (NEPS) to implement export control activities. Although it was launched in 2008 as a system that can work with classification, licensing, nuclear material approval, government-to-government assurance, complying with nuclear cooperation agreement (NCA) handled through official documents. In order to enhance systematic management for items subject to NCA, KINAC developed a new module for the procedure (hereinafter referred to as “NCA module”) and opened it in 2022. This paper presents the module’s development background, key features, and current operation status. The NCA module prioritizes functional expansion and flexibility, distinct from other tasks for the following reasons. First, the export control duties of classification, export license, and approval for NM are based on domestic law, leading to predetermined target items, application forms, and processes that change only through statutory amendments. In contrast, the implementation of NCA has numerous procedural variables, varying across countries in scope, content, and procedures. Therefore, if the function is over-standardized, there would be many exceptions that the system cannot resolve in practice. Second, the existing NEPS process entails a one-time decision or approval for each application, while the implementation of the agreement encompasses four related procedures for each item: prior notification, written confirmation, shipment notification, and receipt confirmation. Even some steps may be omitted depending on the case. The other difference is the working process. The implementation of NCA must be initiated from the government, so the existing methods, beginning with the licensee filling a form, cannot be adopted as it is. The NCA module has adopted a new reference numbering system to resolve these challenges. It enables the creation of multiple procedures under one reference number on an item to expand the tasks and make it possible to omit some steps or to reflect case-by-case concerns in each stage. It also provides a consolidated view of multiple notifications related to a single item, ensuring to deal with even long-running tasks without missing any obligations until the final procedure. Moreover, some of the data in the NCA module is extensible by allowing users to manage the list themselves. For example, the system can respond to new agreements by allowing users to add and modify codes that distinguish counterparty countries. As a result, the current NCA module accommodates a variety of implementation scenarios, including split shipments, the procedural omissions, and the modification of additional counterparties, offering enhanced flexibility and adaptability.

Regulators conduct inspections and issue non-compliance notice, and it is necessary to examine whether this is equivalent a corrective order. A corrective order imposes binding obligations on a business, and violations of it can result in sanctions such as fines, license revocation, or suspension. Therefore, if it is a corrective order, it must go through procedures such as prior notification under the Administrative Procedure Act. However, so far, no such procedures have been followed when issuing non-compliance notice. There are three possible interpretations of it: 1) the issuance of a non-compliance notice is not a corrective order but a part of an inspection, 2) the issuance of a non-compliance notice is a corrective order but not a disposition, and 3) the process of hearing opinions and prior notification was carried out during the inspection. However, if it is a part of an inspection, it should be issued by KINAC or KINS, which is entrusted with the inspection, but it is issued by the Nuclear Safety and Security Commission, and it is a disposition because it makes specific demands, and the corrective orders themselves have not gone through the procedure of hearing opinions. Therefore, in order for a non-compliance notice to be enforceable unlike a recommendation and to be issued by the Nuclear Safety and Security Commission instead of the inspection agency, the law should be amended and the procedure of prior notice and hearing opinions required by the Administrative Procedure Act should be carried out at the issuance stage.