In the case of nuclear projects, when developing a new reactor type, it is necessary to confirm the reactor type, secure the safety, and especially obtain the construction permit approval of the licensing authority for construction. Schedule management is necessary to carry out nuclear projects, and progress rate management of project progress management is largely composed of three elements: scope management, cost management, and resource management. However, in the case of the small modular reactor (SMR) project currently being carried out, it is difficult to calculate the progress rate including budget and resources due to the nature of the project. Therefore, in the SMR project, it took two years from the beginning to prepare the integrated project master schedule (IPMS) to prepare the draft, and then two revisions were made over a year and a half. In this SMR project, we will consider the entire construction period such as design, purchase and production, construction, commissioning, and operation in terms of scope management. The entire document list was created using the document review and approval sheet created at the beginning of the design. In the PMIS (Project Management Information System), the number of approved documents was calculated by comparing the list of engineering documents. In the purchase production part, the main core equipment such as the primary system nuclear steam supply system (NSSS), the secondary system turbine and condenser, and the man machine interface system (MMIS) are managed. Purchasing and manufacturing management shall be managed so that major equipment can be delivered in a timely manner in accordance with the schedule for delivery of equipment in the IPMS. In order to prevent delays in the start of production, it is necessary to minimize the waiting time for work through advance management tasks such as insurance of drawing, stocking of materials, availability of production facilities, etc. In this way, we decided to carry out the schedule management for the design, purchase and manufacturing part in the SMR project first, and the installation, construction and commissioning part will be prepared for the future schedule management.

Most Small Modular Reactors currently under development are pursuing designs that can demonstrate flexibility in terms of construction and operation, and seeking to adopt innovative technologies to implement them, which is a very big challenge not only from the developer’s perspective but also from the regulator’s perspective. For the successful development of SMRs, it is necessary to move away from the existing prescriptive regulatory approach and exercise regulatory flexibility to sufficiently reflect design characteristics. The reason why SMR development is actively progressing around the world is to overcome the limitations of existing Light Water Reactors. Licensing advanced reactors such as MSR, VHTR, and microreactors requires a different approach from the existing conservative regulatory framework, taking into account changing regulatory environment. With the development of information technology and artificial intelligence, new types of threats are emerging, most of which are related to nuclear security. The IAEA, as well as leading countries such as the United States and Canada, require that safety, security, and safety measures be reflected in the early stages of design (Safety, Security, Safeguards by Design) and should be applied in the regulatory process. In addition, it is recommended to design a system that can achieve synergy effects by identifying in potential issues that may cause regulatory interference between safety and security (SSI, Safety-Security Interface). The competitiveness of SMR in the international market will be highly dependent on the degree to reflect the importing countries’ requirements. Since most SMRs currently under development do not have significant differences in safety goals, multi-purpose usability, etc., it is necessary to faithfully reflect the environmental factors necessary for SMR operation in the adopting country in the design. The major issues expected are mostly nuclear security-related rather than safety, and the physical characteristics of the site including the geopolitical conditions of the importing country must be taken into consideration. In this paper, the necessity of SMR nuclear security regulation and the way how to reflect the Security by Design on SMR will be presented.

Korean innovative SMR has been implemented developing with improved safety/economy and i- SMR technology development project to secure a competitive edge in SMR. For nuclear power plants, according to the revision of the Nuclear Safety Act (2013.6), it is mandatory to be reflected in the aging management program of nuclear power plants, and the aging management and regulation of major nuclear power plants are being strengthened. For i-SMR, chemistry environment and management strategy is essential to mitigate corrosion and radiation fields, since it has compacted and integrated module designs. Since 1994, zinc injection into the reactor coolant system (RCS) has been applied more than 100 PWRs in the world to mitigate primary water stress corrosion cracking (PWSCC) and to reduce outof- core radiation fields. In domestic NPPs, 7 have been applying zinc injection and had up to 90% radiation field reductions. For this reason, SMR needs to apply zinc injection for chemistry strategy. Zinc target concentration will be 5~40 ppb at i-SMR, based on Ni-Fe-Cr materials as same as PWRs. Zinc injection location is in volume and purification control system between the volume control tank and charging P/P where the pressure is moderate. Zinc injection skid can consist of two micro-controllable pump (one for operation and one for stand-by) and one injection tank (batching tank for zinc solution). Zn, Ni, Si, Fe, and activated corrosion products should be monitored to identify zinc injection controls and trends. Flux mapping for core performance monitoring should be evaluated. The application of zinc will be essential and effective and bring sustainable reliability for corrosion control and mitigation strategy to meet the risk-free i-SMR development.

The configuration management system was implemented on the basis of a document management system that secured stable understanding, scalability, document security, and convenience in small modular reactor. To reduce the cost and risk of errors, configuration management is implemented to maintain a balance between design requirements, physical configuration, facility configuration information. In the initial stages, configuration change review procedures was developed with the main purpose of change management such as classification system management, configuration control committee management, configuration change review preparation, configuration control committee operation, followup measures, current status and tracking management. The preparation of the configuration change review consisted of preparation, distribution approval, designation of reviewers, review, collection of review opinions, and preparation of resolution results. In the operation of the configuration control committee, it was conducted by designating review members, reviewing members, collecting operation, and approval them. The next step is to supplement and develop the requirements of IEEE Std 828-2012, such as configuration management planning, configuration management control, configuration identification, configuration change control, configuration status monitoring, configuration audit, interface management, and release management. Through this, issue raising, action management, and baseline management will be implemented.

Radioactive source terms are important factor in design, licensing and operation of SMR (Small Modular Reactor). In this study, regulatory requirements and evaluation methodology for normal operation on NuScale SMR, which received standard design certification approval on September 11, 2020 from US NRC, are reviewed. The radioactive waste management system of nuclear power reactor should be designed to limit radionuclide concentration in effluents and keep radioactive effluents at restricted area boundary ALARA according to 10 CFR 20 and 10 CFR 50 Appendix I. Also, in general, the coolant source term to calculate the off-site radiological consequences for normal operation of SMR should be determined by using models and parameters that are consistent with regulatory guide 1.112, NUREG- 0017 and the guidance provided in ANSI/ANS-18.1-1999, and the result should be corrected by reflecting the design characteristics of SMR. The coolant source term of NuScale, unlike the case of large NPPs, cannot rely solely on empirical source term data, because the NuScale source term is based on first principle physics, operational experience from recent industry, and lessons learned from large PWR operation. Fission products in reactor coolant are conservatively calculated using first principle physics in SCALE Code assuming 60 GWD/MTU. The release of fission products from fuel to primary coolant based on industry operational experience is determined as fuel failure fraction of 0.0066% for normal operation source term and 0.066% for design basis source term while coolant source term of large NPP is calculated by using ANSI/ANS-18.1 for normal operation and fuel failure fraction of 1% for design basis source term. Water activation products in reactor coolant are calculated from first principles physics and corrosion activation products are calculated by utilizing current large PWR operating data (ANSI/ANS 18.1- 1999) and adjusted to NuScale plant parameters. Also, because ANSI/ANS 18.1-1999 is not based on first principle physics models for CRUD generation, buildup, transport, plate-out, or solubility, NuScale has incorporated lessons learned by using ERPI’s primary water chemistry and steam generator guidelines to ensure source term is conservative and design of materials used cobalt reduction philosophy to help ensure the coolant source term are conservative. Based on the coolant source term calculated according to the above-described method, the annual releases of radioactive materials in gaseous and liquid effluents from NuScale reactor are evaluated. Currently, Small Modular Reactors such as ARA, SMART 100 are under review for licensing in Korea. This study will be helpful to understand how the reactor coolant system source terms are defined and evaluated for SMR.

Ni–Cr–Al metal-foam-supported catalysts for steam methane reforming (SMR) are manufactured by applying a catalytic Ni/Al2O3 sol–gel coating to powder alloyed metallic foam. The structure, microstructure, mechanical stability, and hydrogen yield efficiency of the obtained catalysts are evaluated. The structural and microstructural characteristics show that the catalyst is well coated on the open-pore Ni–Cr–Al foam without cracks or spallation. The measured compressive yield strengths are 2–3 MPa at room temperature and 1.5–2.2 MPa at 750oC regardless of sample size. The specimens exhibit a weight loss of up to 9–10% at elevated temperature owing to the spallation of the Ni/Al2O3 catalyst. However, the metal-foam-supported catalyst appears to have higher mechanical stability than ceramic pellet catalysts. In SMR simulations tests, a methane conversion ratio of up to 96% is obtained with a high hydrogen yield efficiency of 82%.

휴전국인 우리나라는 의무복무제도를 시행하고 있다. 이에 취업 및 진학을 한 20대 초반의 사회 초년생은 군 입대 문제로 많은 고민과 큰 걱정을 하고 있다. 이에 군에 대한 부정적인 인식과 군 생활 적응은 사회가 같이 풀어야 할 문제이다. 따라서 방송사 등 문제 해결을 위해 다각적으로 노력하고 있으나 역부족이다. 실제 군 입대 후 스트레스 및 불안정 심리상태의 장병 비중이 높다. 따라서 본 연구는 군 생활에서 일상적인 방법을 통해 스트레스, 불안감을 감소시키고, 집중력을 향상 시키고자 실행하였다. 주의 집중력 증가 및 스트레스, 불안감의 변화를 측정하기 위해 SMR파 대역의 주파수를 직접 노출시킨 실험군과 그렇지 않은 대조군으로 실험을 진행하였다. 실험군과 대조군대한 대응표본 t-검정 결과는 신뢰수준 95%에서 t=2.487, p=0.042로 유의차가 인정되었다. 즉, 가상사격영상에서 특정 주파수를 제시한 실험군의 피실험자들이 스트레스 및 불안정 심리의 완화효과가 발생하였다. 본 실험의 결과를 활용하면 젊은 장병들의 군 생활 적응에 효과가 높은 것으로 사료된다. 추후 연구에서는 심전도와 뇌파의 상관관계의 확인이 필요하다.

본 연구에서는 질병 데이터를 활용한 사망률의 지도화에서 지역별 사망률의 변동성을 안정화할 수 있도록 하는 베이지언 기법을 적용하고, 기본적으로 활용되고 있는 SMR (Standardized mortality ratio)과 그 결과를 비교하였다. 우리나라 전국의 시군구 단위의 전립선암 사망자 수 데이터에 표준화와 베이지언 기법을 적용하고, 산출된 사망률을 지도화하여 기존에 없던 우리나라의 전립선암 사망률 지도를 질병 지도의 예시 자료로 작성하였다. 분석 결과, Bayesian 모델링 기법을 통해 계산된 위험비는 기존 SMR에 비해 좀 더 수렴된 형태의 안정적인 통계량을 가지는 것을 알 수 있었다. 국지적 Bayesian 기법은 이웃 지역들의 정보만을 반영하여 위험비를 평활화하기 때문에 본 연구에서 사용된 전역적 기법들과 비교할 때 평활화의 강도가 크지 않았다.

본 실험에서는 반사층(reflector)을 이용한 FBAR (Film Bulk Acoustic Resonator) 즉, SMR (Solidly Mounted Resonator) 제조에 필요한 재료들의 최적 증착 조건을 설정하여, 이를 바탕으로 제조한 SMR의 특성을 보여주었다. SMR은 상하부 전극층, 압전 박막층, 반사층, 기판으로 구성된다. 상하부 전극으로 알루미늄(Al) 금속 박막을 사용하였고 압전 박막층으로 산화아연(ZnO) 박막을 사용하였다. 실리콘(Si) 기판과 하부 전극 사이에 위치하는 반사층은 5층의 이산화규소 (Si2)와 텅스텐(W) 박막으로 구성되었다. 상하부 전극은 dc 스퍼터링 방법으로 증착아였으며 반사층과 압전 박막층은 rf 스퍼터링 방법으로 증착하였다. 최적 증착 조건에서 증착된 산화아연 (ZnO) 박막은 rocking curve에서 표준편차가 2.17˚의 우수한 c축 우선배향성, 비저항은 104 Ωcm이상, 막 표면 거칠기(rms roughness)는 10.6Å의 특성을 나타내었다. 최적 증착 조건에서 증착된 텅스텐(W)과 이산화규소(Si2) 박막의 특성은 박막 거칠기 (rms roughness)가 각각 16 Å, 33 Å을 나타내었다. 또한 증착된 알루미늄 금속 박막의 비저항은 5.1×10-6 Ωcm이었다. 반도체 기본 공정을 이용하여 면적 250×250 μm2의 SMR 소자를 만들고, 네트웍 분석기로 SMR 소자의 공진 특성을 분석하였다. 공진특성은 1.244 GHz에서 직렬공진, 1.251 GHz에서 병렬공진을 나타내었다. SMR 소자의 공진특성에서 공진기의 Q값은 1200이었다.