For safe management of spent nuclear fuels, they should be delivered to repository or waste disposal site. As the amount of spent nuclear fuel transportation is expected to increase in the future due to the provision of an intermediate storage facility, the necessity to secure transportation cask is emerging. In order to secure the spent nuclear fuel transportation cask, it is necessary to analyze the regulatory processes for domestic and foreign spent nuclear fuel transportation cask. In this study, the regulatory processes for domestic and foreign spent nuclear fuel transportation cask was analyzed. In this study, the IAEA, US, and Korea spent nuclear fuel transportation cask regulatory processes were analyzed. The domestic and foreign spent nuclear fuel transportation cask regulatory processes consist of design phase, manufacturing phase, and operation phase. In the design stage, the transport requirements are designed in accordance with the safety requirements of international organizations and countries. The application to be submitted when applying for approval should include a safety analysis report, evidence proving compliance with safety requirements et al. In the manufacturing stage, it is a stage to check whether the safety requirements are satisfied before the first use after manufacturing the transportation cask. Inspections include welding inspection, leakage inspection, shielding inspection, and thermal inspection. In the operation stage, it is a stage of periodically performing inspections for continuous maintenance of the package when the transportation cask is used. The inspection items to be performed are similar to the manufacturing stage and typically include performance inspection of components and leakage inspection. In this study, domestic and foreign spent nuclear fuel transportation cask regulatory processes were analyzed. It was found that the domestic and foreign spent nuclear fuel transportation cask regulatory processes consist of the design phase, the manufacturing phase, and the operation phase. The results of this study can be used as basic data for policy decision-making for the spent nuclear fuel cask.

Nuclear power plants (NPPs) are designed in consideration of redundancy, diversity, and independence to prevent leakage of radioactive materials from safety of view, and a contingency plan is established in case of DBA (Design Basis Accident) occurrence. In addition, NPPs have established contingency plans for physical attacks, including terrorist intrusions and bomb attacks. However, the level of contingency plan caused by cyberattacks is quite insufficient compared to the contingency plan in terms of safety and physical protection. The purpose of this paper is to present the problems of cyberattack contingency plan and methods to supplement it. The first problem with cyberattack contingency plan is that the initiating event for implementing the contingency plan is undecided. In terms of safety, the DBA is identified as an initial event, and each contingency plan is based on the initial events specified in the DBA such as Loss of Coolant Accident and Loss of Offsite Power. In terms of physical protection, each has a contingency plan by identifying bomb attacks and terrorist intrusions in Protected Area and Vital Area as initial events. On the other hand, in the contingency plan related to a cyberattack, an initial event caused by a cyberattack is not identified. For this, it is necessary to classify the attack results that may occur when the CDA is compromised based on the attack technique described in Design Basis Threat. Based on this, an initiating event should be selected and a contingency plan according to each initiating event should be established. The second problem is that there is no responsibility matrix according to the occurrence of the initiating event. From a safety point of view, when a DBA occurs, the organization’s mission according to each initial event is described in the contingency plan, and related countermeasures are defined in case of an accident through Emergency Operation Procedure. In the case of physical protection, referring to IAEA’s Regulatory Guide 5.54, the organization’s responsibility is defined in matrix form when an initial event such as a bomb attack occurs. In this way, the responsibility matrix to be carried out in case of initiating events based on the defined initial event should be described in the contingency plan. In this paper, the problems of the cyberattack contingency plan are presented, and for this purpose, the definition of the initial event and the need for a responsibility matrix when the initial event occurs are presented.

In response to the increase in international terrorism threats and demands for terrorism prevention and response activities, the Act on Counter-Terrorism for the Protection of Citizens and Public Security was enacted in 2016, and the need for research to strengthen protection against explosive threats was raised. In the same manner, the Design Basis Threats, which become the standard for the design and evaluation of physical protection systems for nuclear facilities, have been developed and it includes explosive threats. However, the regulatory standards for physical barriers against explosive threats are still not established. Therefore, it is first required to set up a performance database of physical barriers subject to blast loading in order to prepare the regulatory standards. In this study, the pressure with the trinitrotoluene (TNT) charge weights of 0.5-2 kg as a function of time was calculated using Ansys Autodyn software by assuming that the TNT is used for malicious purposes and is attached to a reinforced concrete (RC) corridor wall. The shape of the corridor was the 3×3×6 m cuboid with a rectangular hole of 1.78×1.78×6 m. The RC walls, which make up the corridor, contained the reinforcing bars with a spacing of 0.229 m and a diameter of 0.036 m. The spherical charge of a TNT was placed 0.2 m away from a RC wall in the middle of the corridor. To measure the reflected pressure after the internal explosion with a TNT, three pressure gauges were installed on the three sides of the RC walls in the middle of the corridor, respectively. The results showed that the peak reflected pressure on a RC wall with the standoff distance of 0.2 m was about ten times higher than the opposite RC wall with the standoff distance of 1.58 m in the same condition of TNT charge weight. Thus, it was verified that blast loads are highly affected by standoff distance. It seems that preventing the explosive detonation close to a physical barrier is strategically important to maintain the integrity of the physical barrier.

The detector response was simulated to design a fork detection system for verifying the characteristics of spent fuel. The fork detection system currently used consists of two fission chamber and an ion chamber, and it is nuclear safeguard equipment that measures the gross neutrons and gross gamma rays emitted from the spent fuel assembly to identify the characteristics of the spent fuel and verify the authenticity of the operation history. In order to improve the current fork detection system, we are developing a system that applies CZT, a room temperature semiconductor detector, and a stilbene detector, which is an organic scintillator. Depletion calculations were performed using the ORIGEN code to determine the radiological characteristics emitted from spent nuclear fuel assembly. The flux of radiation emitted from the spent nuclear fuel assembly was calculated by changing the conditions such as initial enrichment, burnup, and cooling time, which are major variables of spent fuel assembly. The calculated result is used as the source term of the particle transport code. Considering the general operating conditions of the pressurized light water reactor, the conditions were changed in the range of 3-5% for initial enrichment and 30-72 GWD/MTU for burnup, and the cooling time was given within 10 years. MCNP 6.2, a Monte Carlo simulation code, was used to simulate the detector response to radiation emitted from spent nuclear fuel assembly. According to the shape, size, and position of the CZT detector, the gamma counts incident on the detector were calculated and derived the initial design of our fork detection system.

Monitoring a state that intentionally hides its nuclear activity via open-source information is akin to looking through a black box. Direct information on the state’s nuclear activity remains in the dark, leaving scholars to speculate how much nuclear material or warheads are being produced. Nevertheless, a state’s nuclear program consists of a complex network that ranges from producing weapon-grade nuclear materials by operating its nuclear facilities to securing resources to fund these activities. These indirect activities allow a narrow window of opportunity for researchers to map a state’s activity that sometimes may not be directly linked to nuclear activity per se but is significant to maintaining and operating its nuclear program. These may include malicious cyberattacks to steal or launder cryptocurrency and facilitating cooperation with fellow rogue states that do not comply with the NPT and nuclear nonproliferation regime. The problem lies in how researchers can map this network. Much of the literature that uses text analysis uses data from either (1) formal statement, reports, and documents or (2) journal articles to extract relations between topics that is otherwise difficult to surmise. This study, however, analyzes news articles containing keywords related to a states’ nuclear activity such as international sanctions, trade activities, other states’ policy etc. While news articles fail to live up to the academic rigor of journal articles and unlike formal documents may sometime contain misinformation or incorrect facts, they are a valuable medium to show the day-to-day activity of a state. Although bias may exist as particular news articles may or may not be chosen for text analysis, by using articles collected from 2021 to 2022, this study argues it is enough data to show a short-term trend in nuclear activity.

In order to enter a nuclear power plant, access approval is required in advance, and biometric information such as fingerprints of visitors must be registered when issuing a key card, and only those certified through biometric equipment can enter the nuclear facilities (Protected area II). Fingerprint recognizers and facial recognizers are installed and operated in domestic nuclear facilities for access control. Domestic nuclear facilities establish and implement a protection system in accordance with physical protection requirements under the “Act on Physical Protection and Radiological Emergency” and “Physical Protection Regulations” of each nuclear facility. Detailed implementation standards are specified in Regulation Standard (RS) documents established and distributed by KINAC. Biometrics are mentioned in a KINAC RS-104 (Access Control) document. In this study, it was analyzed what points should be considered in order to prepare for performance tests and establish plans for biometric devices. In order for the results of performance evaluation of biometric devices to obtain high reliability and to be applied to nuclear facilities in the future, standardized performance evaluation targets, procedures, standards, and environments must be created. In order to collect samples such as fingerprints for performance evaluation, the size roll of the sample shall be determined, and the appropriateness of the sample size shall be evaluated in consideration of reliability and error range. In addition, the analysis results for the characteristics (gender, age, etc.) of the sample should be presented. When collecting samples, conflicts with other laws such as personal information protection should be considered, and the reliability of the performance test result data should be analyzed and presented. Quality evaluation should also be performed on forged biometric information data such as silicon fingerprints. In addition, when establishing a performance evaluation plan, a systematic evaluation procedure should be established by referring to domestic and foreign certification and evaluation systems such as the Korea Internet & security Agency (KISA). In order to improve the completeness of the access control system using the biometrics of nuclear facilities, it is necessary to test the performance of biometric devices and to install and operate only devices that have the ability to defend against counterfeit technology. In this study, it was analyzed what points should be considered in order to prepare for performance tests and establish plans for biometric devices.