In a group-testing method, instead of testing a sample, for example, blood individually, a batch of samples are pooled and tested simultaneously. If the pooled test is positive (or defective), each sample is tested individually. However, if negative (or good), the test is terminated at one pooled test because all samples in the batch are negative. This paper considers a queueing system with a two-stage group-testing policy. Samples arrive at the system according to a Poisson process. The system has a single server which starts a two-stage group test in a batch whenever the number of samples in the system reaches exactly a predetermined size. In the first stage, samples are pooled and tested simultaneously. If the pooled test is negative, the test is terminated. However, if positive, the samples are divided into two equally sized subgroups and each subgroup is applied to a group test in the second stage, respectively. The server performs pooled tests and individual tests sequentially. The testing time of a sample and a batch follow general distributions, respectively. In this paper, we derive the steady-state probability generating function of the system size at an arbitrary time, applying a bulk queuing model. In addition, we present queuing performance metrics such as the offered load, output rate, allowable input rate, and mean waiting time. In numerical examples with various prevalence rates, we show that the second-stage group-testing system can be more efficient than a one-stage group-testing system or an individual-testing system in terms of the allowable input rates and the waiting time. The two-stage group-testing system considered in this paper is very simple, so it is expected to be applicable in the field of COVID-19.

Thermal management is significant to maintain the reliability and durability of electronic devices. Heat can be dissipated using thermal interface materials (TIMs) comprised of thermally conductive polymers and fillers. Furthermore, it is important to enhance the thermal conductivity of TIMs through the formation of a heat transfer pathway. This paper reports a polymer composite containing vertically aligned electrochemically exfoliated graphite (EEG). We modify the EEG via edge selective oxidation to decorate the surface with iron oxides and enhance the dispersibility of EEG in polymer resin. During the heat treatment and curing process, a magnetic field is applied to the polymer composites to align the iron oxide decorated EEG. The resulting polymer composite containing 25 wt% of filler has a remarkable thermal conductivity of 1.10 W m− 1 K− 1 after magnetic orientation. These results demonstrate that TIM can be designed with a small amount of filler by magnetic alignment to form an efficient heat transfer pathway.

Though many treatment technologies of contaminated water have been developed for a long time, it is still difficult to find a suitable method for large volumes of low radioactivity tritium-contaminated water. For this reason, most of the tritium-contaminated water been discharged to the biosphere or been stored in a special control area as radioactive waste. Activated carbon is a common material, but since there are few data on the treatment of tritium-contaminated water, its adsorption behavior to HTO is worth studied. In our study, for the tritium-contaminated water having a low radioactivity concentration (350-480 Bq/g), adsorption experiments were performed with activated carbon. The effects on the selective adsorption of HTO were investigated for temperature (5-55°C), hydrogen peroxide (1-10wt%) and activated carbon reuse (1-6 times) under non-equilibrium conditions. The treatment of activated carbon significantly reduced the radioactivity of tritium-contaminated water around 60 minutes of adsorption time. In order to clearly analyze the experimental results, positive factors and negative factors on the HTO selectivity were separately evaluated according to the adsorption time. Temperature and the reuse of activated carbon were evaluated as negative factors for HTO selectivity of activated carbon, whereas hydrogen peroxide (> 5wt%) was evaluated as a positive factor. By the evaluation method of separating the influencing factors into two types, the adsorption experimental results of HTO could be understood more clearly.

Hydrogen isotopes (H, D, T) separation technologies have received great interest for treatments of tritiated liquid waste produced in Fukushima. In addition, the separated deuterium and tritium can be utilized in various industries such as semiconductors and nuclear fusion as expensive and rare resources. However, separating hydrogen isotopes in gas and liquid forms still requires energyintensive processes. To improve efficiency and performance of hydrogen isotope separation, we are developing water electrolysis, cryosorption, distillation, isotope exchange, and hydrophobic catalyst technologies. Furthermore, an analytical method is studied to evaluate the separation of hydrogen isotopes. This presentation introduces the current status of hydrogen isotope research in this research group.

The magnetic Cs adsorbent functionalized with hierarchical titanium-ferrocyanide were fabricated for the highly efficient magnetic removal of radioactive cesium from water. The new magnetic Cs adsorbent has a core–shell structure that comprises a Fe3O4 core, an interlayer of SiO2, and a titanium-ferrocyanide-shell with hierarchical nanostructure. At first, the magnetic Fe3O4 nanoparticles synthesized via a hydrothermal reaction were coated with SiO2. Then, TiO2 were coated on the surface of SiO2 coated magnetic nanoparticles. Finally, the hierarchical titanium-ferrocyanide composed of 2-dimensional TiFC flakes was fabricated on the surface of core-shell MNP@SiO2@TiO2 microparticles using a TiO2 sacrificial template via a simple reaction with potassium ferrocyanide (FC) based on the Kirkendall-type diffusion. The resulting magnetic Cs adsorbent shows higher adsorption capacity of 416 mg/g than other magnetic Cs adsorbents (below 200 mg/g) because of the increased effective surface area of hierarchical titanium-ferrocyanide. Therefore, our Magnetic Cs adsorbent functionalized with hierarchical titanium-ferrocyanide has excellent potential for the treatment of various 137Cs-contaminated sources.

Organic waste generated by small and medium-sized (S&M-sized) metal decontamination in NPP decommissioning. To lower the concentration of these organic substances for a level acceptable at the disposal site, the project of “Development of Treatment Process of Organic Decontamination Liquid Wastes from Decommissioning of Nuclear Power Plants” is being carried out. The conditioning and treatment process of organic liquid waste was designed. Also, the literature was investigated to make simulated organic liquid waste, and the composition of these waste was analyzed and compared. As the decontamination agent, organic acids such as EDTA, oxalic acid, citric acid are used. The sum of the concentrations of these organic materials was set to a maximum value of 1,000 ppm. The major metal ions of the decontamination liquid waste estimated are 59Fe, 51Cr, 54Mn, 63Ni, and the concentrations are respectively 527, 163, 161, 159 ppm. Additional major metal ions are 60Co, 58Co, 137Cs. 58Co is replaced by 60Co because it has the same chemical properties as 60Co. Unlike the HLW, the contamination level of S&M-sized metal in primary system was quite low, so 60Co is set to 2,000 Bq/g. Considering the contribution of fission and gamma ray dose constant, 137Cs was estimated to 360 Bq/g. Also, suspended solids of decontamination liquid waste were set at 500 ppm. Under these assumptions, the simulated organic liquid waste was made, and then organic substances and metal ions were analyzed with TOC analyzer and ICP-OES. The TOC analysis value was expected to 392 ppm in consideration of the equivalent organic quantity. the test result was 302 ppm. Some of organics appears to have been decomposed by acid. The values of metal ions (Fe3+, Cr3+, Mn2+, Ni2+) analyzed by ICP-OES are 139, 4, 152, 158 ppm, respectively. A large amount of Cr3+ and Fe3+ were expected to exist as ions, but they existed in the form of suspended solid. Mn2+ and Ni2+ came out similar to the expected values. The designed conditioning and treatment process is largely divided into pretreatment, conditioning, and decomposition processes. After collecting in the primary liquid waste storage tank, large particulate impurities and suspensions are removed through a pretreatment process. In the conditioning process, treated liquid waste passes through UF/RO membrane system, and pure water is discharged to the environment after monitoring. Concentrated water is decomposed in the electrochemical catalyst decomposition process, then this water secondarily passes through the RO membrane system and then discharged to the environment after monitoring. Through an additional experiment, the conditioning and treatment process will be verified.

According to Article 3(2) of the NPT and NSG the Guidelines, the exporting country should be guaranteed the import country’s willingness to implement nuclear non-proliferation and the level of implementation before the transfer of Trigger List Items. Also, unknown or new end-users could be officially identified through GA procedure. Accordingly, Korea government requests the importing country a formal Governmental Assurance (GA), before issuing an export license. This study summarizes GA items and characteristics. First, GA is The NSG guidelines suggests four items that should be assured by importing countries: peaceful use of export items, full-scope safeguards application, physical protection measures, and retransfer control. Therefore, these four items are generally requested based on the NSG guidelines. However, if they are already guaranteed by bilateral nuclear cooperation agreement, the GA could be based on the nuclear cooperation agreement. The GA procedure could be omitted in the case of concluding an administrative agreement that imposes another implementation procedure. The levels of requested GA requested vary with the countries, since the NSG guidelines are just recommendations that are not legally enforceable. Korea requests the level based on the NSG guidelines. Among the four GA items, peaceful use of export items is the most fundamental obligation, and levels of safeguards and physical protection of the importing country could be verified in advance by reviewing the conclusion status of international agreement with the IAEA. Thus, the important thing for the licensee to consider is to decide the level of retransfer control. The NSG guidelines suggest two levels of retransfer control, taking into account the sensitivity of the export items and the level of safeguards in the end-user country, which is either to receive GA from the third receiving country at an equivalent level with that originally requested from exporting country, or to get a prior consent by the exporting country. The latter should be approached more carefully, as requiring a prior consent is not only to have authority, but also to have responsibility when problem occurs. In addition, the level of retransfer control must be decided through sufficient reviewing on the transaction characteristics, it may affect the domestic export industry.

By Foreign Trade Act and the relevant laws, any organization which intends to export strategic items shall be classified whether the products, S/W, or technology are strategic items and obtain an export license from the Nuclear Safety and Security Commission (NSSC) in case those are nuclearrelated strategic items. The NSSC and KINAC conduct outreach activities to enhance the recognition and implementation of nuclear export and import control. However, ensuring that all target organizations identify and comply with relevant legislation and laws is difficult. Therefore, the government and regulators should continuously make efforts to reduce blind spots for nuclear export and import control. KINAC established the National Nuclear Technology Information Collection and Analysis System (NNTICAS) to find nuclear-related companies through online website information of various companies and to list organizations that handle nuclear-related strategic items. Based on the NICE corporate information website, NNTICAS finds related companies using dynamic collection methods through interactions such as search word input, search button input, check box click, and collected text from each company website using static collection methods through URL address access and HTML source code extraction. After that, the text contained on the company website is analyzed to check whether the predefined normalized word is included, and if the normalized word appears at a certain number or higher, it is judged as a potential target company dealing with nuclearrelated strategic items. Information on the potential target company is compared with the export controlled item list and finally classified as a target company dealing with nuclear-related strategic items. According to the comparison a manually analyzed result of potential target companies and finally selected target companies NNTICAS, it is confirmed that predefined normalized words need to be more detailed, and a controlled item list such as axes (0B001.b.2) needs to be additionally processed. In addition, if the collection is repeated without completing the previous classification of the collected corporate information, it is also possible to collect companies in cosmetics, semiconductors, and displays. Although it was confirmed that some supplementation is needed to use this system to select target companies for the outreach activity, it is also confirmed that target companies for outreach activity can be expanded through this system and is expected to increase the implementation rate and reduce the blind spot for nuclear export and import control.

Under the bilateral nuclear cooperation agreements (NCA) and its administrative arrangement (AA), Korea annually exchanges the inventory of subject items (including nuclear materials (NM), non-nuclear materials, equipment, and related information) with US, Canada and Australia. Also, the government performs export control procedures such as notification or prior consent during importing and exporting of relevant items. It makes NCA a means of realizing the nuclear non-proliferation regime. However, it raises difficulties in management because the entity that uses and treats those items are end-user, not the authorities of AA, the government agency of each country. Accordingly, to increase the accuracy and effectiveness of item management at the national level, it is required to establish a system for the individual company that has the NCA items, considering the characteristics of each company. In this study, significant companies are classified into more than three types, and the management system of the items subject to the agreement is analyzed. Each company’s item management status has different characteristics depending on its role (position) within the entire nuclear fuel cycle, the type of facility, its possessed items, the main form of national trade, and the frequency of domestic movement. Those differences lead to diversity in the management systems currently owned by each company. For example, from the perspective of nuclear materials, institutions requiring bulk management have systematically organized their management system and obligation code program compared to the ‘item institutions’ that can track batch history for all facility inventory changes. Although Domestic law imposes only the duty of origin management on NMs, fuel manufacturers or research institutes have established their standard obligation codes to manage multiple obligations. The non-nuclear materials and equipment can be easily tracked and controlled by individual items. However, the management of NCA items is a complicated task involving various processes, from importing goods to using, storing, managing inventory change, selling to others, or fulfilling the obligations of AA when exporting. In particular, when the movement of items within a company or international trade occurs frequently, or when the end-users are diverse, the management difficulties increase. So a system that can accurately convey and track items subject to the AA is needed. In addition, since various entities are related, it is necessary to improve understanding of NCA items to increase the system’s utilization and effectiveness. The comparison result and requirement for system improvement based on the review above will be reflected in the history management system for items subject to NCA under development.

Nuclear Suppliers Group (NSG), one of the international multilateral export control systems, has designated Trigger List Item and Nuclear Dual-Use Item as control items. The Trigger List Item includes the “Especially Designed or Prepared (EDP)” term as control context. This term is very subjective and vague. Why this ambiguous term reflected in the control context? The EDP term is one of the essential elements of multilateral nuclear export controls since the NPT came into effect in 1970. The EDP concept is the basis of the rules in the Trigger List of NSG Part 1. NSG control items and contexts are decided through consensus among Participate governments, and there are three main reasons for reflecting EDP term in the guideline. First, it is to expand the control network by preventing the diversion of concerned traders. Secondly, technology development is faster than the regulatory speed, and it is tough to put all the items on the list. And last, it is to control other sensitive information such as concerned traders’ shopping list. To reduce the ambiguity of EDP, the US, UK, and Canada presented their interpretation methods at LEEM, a sub-group of the NSG. The United States and Canada have four location criteria (inside the containment building, RCS system or control, RCS system attachment, outside the containment building) and three purpose criteria (custom-made for nuclear power, whether it is an item according to the nuclear industry standard, not made to order) to determine the EDP items. The United Kingdom considers the original design intent and the purpose for which the item was originally designed. They also think about the nature of any specific or unique design features in terms of an item’s “fit,” “form,” and “function” that determine EDP item. Currently, in the case of KINAC, although it is not a controlled item in Korea, items designated by other countries are controlled as EDP items, and detailed standards for parts are prepared and controlled as EDP items. The interpretation of TL’s EDP differs from country to country, and differences are allowed between member states to some extent. Suppose Korea, like the US, UK, and Canada, examines measures to control EDP and reflects it after benchmarking. In that case, it is expected that it will contribute to reducing the export control loopholes for advanced technologies in the future and improve nuclear transparency through strict implementation of Korea’s export controls.

From 1970 to 1990, North Korea’s trade mainly carried out maritime trade through ports for countries around the world. This trend is due to UN sanctions against North Korea, and after the third nuclear test in 2016, North Korea gradually became isolated from the outside world as it expanded to include maritime sanctions in the form of comprehensive sanctions targeting an unspecified majority of North Korea. The logistics structure of North Korea is due to the logistics infrastructure left during the Japanese colonial period in the 1950s and the political structure of the country, with railroads being the main source of logistics and passenger transportation, and roads being secondary. North Korea faced rapid deterioration and lack of facilities after 1990 due to the lack of investment in facilities and improvement of the operating system despite the advanced logistics infrastructure and operating system compared to the South. In particular, the power shortage in North Korea hindered the operation of the railroad and accelerated the aging of the railroad facilities, which has continued to this day. In the 2010s, 96% of cargo transportation in North Korea’s logistics infrastructure depended on railroads and roads, and ports that were developed until the 1980s have deteriorated with little investment since the economic crisis of the 1990s. Although some ports have been developed since 2010, North Korea’s east and west coasts are separated and there is no function of shipping to connect ports, so it did not have a significant impact on enhancing the nation’s port capacity. As North Korea’s trade dependence on China has increased, North Korea has largely relied on land transport, except for some cargoes that are advantageous for marine transport, such as coal. This structure again leads to a decrease in investment in ports, and the current vicious cycle of causing problems with North Korean port facilities is repeated. In this study, North Korea’s land and marine trade logistics system such as railway, road, and shipping and the trend of foreign trade due to sanctions against North Korea were analyzed. Through this analysis, it is planned to be used as a basis for developing the routes and scenarios through which major nuclear items can be transferred in the event of denuclearization of North Korea in the future.

When exporting nuclear power plants to a third country, the U.S. conditions import countries to join the International Atomic Energy Agency (IAEA) Additional Protocol. At the Korea-U.S. summit, Korea also agreed to maintain equal non-proliferation standards. This paper first analyzes how the U.S. applies the conditions for joining additional protocols to export control policies. The U.S. Atomic Energy Act is a general law in the field of nuclear power that governs both civilian and military use of nuclear power. Article 123 stipulates matters related to “cooperation with other countries.” According to Article 123, the United States must conclude a peaceful nuclear cooperation agreement with another country that stipulates nuclear non-proliferation obligations for nuclear cooperation to a “significant” extent. Article 123 of the Nuclear Energy Act presents nine conditions for signing the Nuclear Cooperation Agreement, and matters related to safeguards are stipulated in Nos. 1 and 2, and only IAEA’s Comprehensive Safeguards Agreement (CSA) is specified as requirements under the current law. As a result of analyzing the countries of the nuclear cooperation agreements currently signed by the United States, the United States is evaluating the AP in terms of the policy as an essential item. Among the nuclear agreements with the United States, three countries, Egypt, Brazil, and Argentina do not have AP in effect. Among them, Brazil and Argentina are recognized by the IAEA as replacing the ABACC with the AP, so only Egypt is not a member of the AP. The nuclear agreement between the U.S. and Egypt was signed in 1981 before the AP existed, and all recently signed agreements were identified as AP-effective countries. As a result of reviewing the U.S. export control laws, the U.S. did not legislate the AP as a condition for peaceful nuclear exports. Reflecting the NSG export control guidelines, AP was legislated as an export license requirement only in exporting sensitive nuclear technology (enrichment, reprocessing). However, it is confirmed that the U.S. policy applies AP entry into force as one of the main requirements for determining whether it is harmful to nuclear exports, along with the conclusion of the Nuclear Cooperation Agreement, the application of the Comprehensive Safeguards Agreement, and military alliance. The appropriate scope of application of the Additional Protocol in Korea and its application plan will be suggested through future research.

In 2004, in order to comply with UN Security Council Resolution 1540, the European Union (EU) came into force with Regulation 428/2009 for the export control of dual-use items, which has been working to prevent the proliferation of weapons of mass destruction (WMDs). In August 2021, it amended the EU 821/2021 to include mandating the introduction of ICPs for exporters in the member countries in order to strengthen controls over the transfer of tangible and intangible technologies. The main contents are as follows; 1) Mandatory introduction of Internal Compliance Program (ICP): Exporters within the EU countries should introduce a transaction review procedure through the ICP in consideration of their size and organization. 2) Export control on Cyber Surveillance Items to protect human rights: In order to protect human rights and comply with the obligations of international human rights law, EU countries should implement export controls on cyber-monitoring items exported from customs zones in the EU. Cyber surveillance items are specially designed to monitor, extract, collect or analyze data such as biometrics through intrusion of information and communication systems or deep packet hijacking. However, items used for purely commercial programs such as billing, marketing, quality service, user satisfaction or network security are excluded. 3) Expansion of the Catch-all system: EU countries should utilize the catch-all system to strengthen export controls on cyber-monitoring items, including dual-use items. 4) Strengthening control over the cloud: Exporters and EU countries should extend the scope of intangible technology transfer, such as electronic media, fax, and telephone, outside the EU’s customs territory, and apply export control regulations such as general or comprehensive licenses to cloud transmissions outside the EU territory. 5) Introduction of large-scale project authorization: To reduce the administrative burden on enterprises (especially small and medium-sized enterprises) and authorities when exporters with individual or collective licenses export to one or more specific end-users for the purpose of large scale projects, provided that they ensure the implementation of an appropriate level of export controls; EU countries may introduce large-scale project license systems in the form of general authorization. Recently, there is a possibility that the ROK would export its nuclear technologies including APR1400 to the EU member countries in the midst of the EU adoption of carbon-zero policy. In this paper, we have analyzed the EU export control regulations and suggested the future direction of nuclear export control programs in the ROK.

In August 2021, in response to the rapidly changing trade environment, including the advancement of Information Communication Technology (ICT) and its services, the European Union (EU) implemented the Dual-Use Items Control Regulation 821/2021 to introduce an Internal Compliance Program (ICP) to the EU countries. Accordingly, the exporters should comply with the regulation to strengthen their transactions review systems. Sweden, Germany, France, and the United Kingdom have implemented ICPs and outreach activities for dual use items. In particular, France explicitly stipulates the introduction of ICP in the law to manage and supervise it. While Sweden, Germany, and the United Kingdom strengthen the supervisory authority of regulatory agencies then companies are encouraged to autonomously introduce ICPs. Before introducing the ICP for the trigger list items (the items) to the Republic of Korea (ROK), a comprehensive export license system for them should be firstly considered based on EU Regulations. Also the comprehensive export license might be implemented by expanding the subject for the existing license on technology export of nuclear plant into the items. The ROK does not introduce an ICP as it does not recognize a self-classification on the items in accordance with the nuclear export control law. However, in preparation for the export to the EU countries that have intentions to introduce nuclear plants, it is necessary to analyze the export control programs of Sweden, Germany, France, and the United Kingdom. Like the programs of Sweden, Germany and the United Kingdom, the EU regulations might be adopted to reduce the regulation burden in the ROK. With the reference of Sweden, the authority could support the Export Control Manager Certification (ECMC) system accredited by civil association then its outreach activities could be diverse and extended. Basically, the ECMC system could consist of Part I, II, III and IV and an applicant could be accredited by a civil association as the ECM after completing the courses of Part I and II. The ECMC courses might be as follow; 1) Part I: the Basic common course for beginner 2) Part II: the National export control system for the items 3) Part III: the International export control regulations 4) Part IV: Re-Certification within the certain period In this paper, we analyzed the export control programs in Sweden, Germany, France, and the United Kingdom and suggested the ECMC system that might be applied to the ROK as above.

Since the 1992 ‘Joint Declaration of South and North Korea on the Denuclearization of the Korean Peninsula’ was agreed, various negotiations and policies have been conducted. There were policies such as CVID, Strategic Patience, Top-Down Approach, Calibrated Practical Approach, Audacious Initiative and the Geneva Agreement, and 9.19 Joint statement by the six-party talks were signed to denuclearize Korean Peninsula. However, starting with the first nuclear test in 2006, North Korea conducted six nuclear tests to develop atomic bombs, boosted fission bombs, ICBMs, and SLBMs to enhance its weapon capabilities. In addition, nuclear security crisis on the Korean Peninsula has been rising day by day as signs of restarting the North Korea’s Yongbyon 5MWe Graphite-moderated reactor were observed and the possibility of a seventh nuclear test have been increased. Since North Korea’s nuclear issue has a lot of influence on international security, especially on the Northeast Asian countries, a realistic denuclearization policy that reflects North Korea’s current domestic situation along with the international situation is needed. It’s been six months since Russia invaded Ukraine on February 24, 2022. The war between Russia, which has nuclear weapons, and Ukraine, which gave up its possession of nuclear weapons due to the Cooperative Threat Reduction (CTR) program known as the Nunn-Lugar program, is expected to have a significant impact on North Korea, which is considering denuclearization due to UN sanctions on North Korea. Therefore, in this study, based on the war patterns of Russia-Ukraine war, perspective on how it could affect North Korea’s denuclearization is analyzed. Also, significance and limitations of the previous nuclear negotiations, the North Korea’s political regime, the ‘five-year strategy for North Korea’s economic development’ and the ‘five-year plan for North Korea’s economic development’ were analyzed to suggest practical DPRK’s denuclearization policy.