Microreactors, a type of Small Modular Reactor (SMR) under 20 MWt, are being developed globally for use in remote areas, utilizing fourth-generation nuclear technology for enhanced safety. However, there are no established standards for their commercialization. This study reviews road transport regulations for microreactors and proposes necessary design loads and evaluation criteria for their transport. Transport concepts were identified through a review of overseas developments, with requirements derived for both accident and normal conditions. The study also presents an approach for evaluating transport stability based on land-based nuclear plant regulations, considering load conditions from drops and puncture impacts, as well as random vibrations during road transport. This work aims to support the design of mobile reactor transport systems and contribute to new regulatory and licensing procedures for advanced reactors.
The primary focus in the nuclear power market revolves around the advancement of small modular reactors (SMRs) featuring fourth-generation nuclear technology. Microreactors, a subset of SMRs, are characterized by their portability due to their very small size. Despite the accelerated development of microreactors, there are currently no regulations concerning their transportation. To pave the way for future regulatory requirements, existing laws and standards were initially examined. This included a review of basic standards, special conditions of the Road Traffic Act, road transport regulations for nuclear material shipments, and physical protection regulations. Additionally, summaries were provided for design standards related to acceleration loads and vibration tests during road transport and land-based nuclear power plant designs. The anticipated outcome of this study is comprehensive coverage of considerations for designing a transport system for micro-nuclear reactors, providing developers the flexibility to selectively apply them to their specific needs. Furthermore, it is anticipated that this information can serve as fundamental data for establishing licensing requirements in the future.
High-quality colloidal CdSe/ZnS (core/shell) is synthesized using a continuous microreactor. The particle size of the synthesized quantum dots (QDs) is a function of the precursor flow rate; as the precursor flow rate increases, the size of the QDs decreases and the band gap energy increases. The photoluminescence properties are found to depend strongly on the flow rate of the CdSe precursor owing to the change in the core size. In addition, a gradual shift in the maximum luminescent wave (λmax) to shorter wavelengths (blue shift) is found owing to the decrease in the QD size in accordance with the quantum confinement effect. The ZnS shell decreases the surface defect concentration of CdSe. It also lowers the thermal energy dissipation by increasing the concentration of recombination. Thus, a relatively high emission and quantum yield occur because of an increase in the optical energy emitted at equal concentration. In addition, the maximum quantum yield is derived for process conditions of 0.35 ml/min and is related to the optimum thickness of the shell material.