Woo Seung Min

Abstract: Corn and soybeans should be sown between 5 cm and 10 cm apart in mixed cultivation to increase protein content and improve productivity of the forage. However, existing sowers cannot plant at intervals of less than 20 cm. Consequently, mixed cultivation of corn and soybeans is currently performed by first sowing corn seeds with a tractor and then manually planting soybean seeds. This method results in irregular intervals between the seeds, it is laborious and time consuming. This study

Abstract Pyro-processing is an emerging technology crucial to the implementation of a closed nuclear fuel cycle. It is distinguished by its method of extracting and recycling actinides from fission products in spent nuclear fuels, utilizing high-temperature molten salt media. Despite its promise, the technology poses proliferation concerns that underscores the imperative for robust safeguards. While the safeguarding framework for aqueous reprocessing facilities that has been established over dec

Policy literacy plays a critical role in enhancing deliberative communication among the public, policymakers, and experts. It also helps develop a positive view of policy by the public, which facilitates public acceptance. Despite its importance, however, policy literacy has received little attention in energy policy practice. Therefore, this study explores factors affecting the public's understanding and knowledge (i.e., policy literacy) of nuclear and new-renewable energy policies. Accordingly

Under normal operating conditions, a pyroprocessing facility removes highly radioactive and nonradioactive fission product waste from used nuclear reactor fuel to recycle the remaining uranium (U), plutonium (Pu), and other actinides contained in it. The products from this facility are separate ingots of U and mixed transuranic elements (TRUs)–uranium (TRU-U). Uranium in both ingots will be depleted U with 235U enrichment less than 1%. The TRU-U ingot will contain neptunium, Pu, americium (Am),

An analysis of a pyroprocessing safeguards methodology employing the Pu-to-244Cm ratio is presented. The analysis includes characterization of representative used nuclear fuel assemblies with respect to computed nuclide composition. The nuclide composition data computationally generated is appropriately reformatted to correspond with the material conditions after each step in the head-end stage of pyroprocessing. Uncertainty in the Pu-to-244Cm ratio is evaluated using the Geary-Hinkley transform

A new methodology, the crack–spallation model, has been developed to analyze gas–solid reactions dominated by crack growth inside of the solid reactant and spallation phenomena. The new model physically represents three processes of the reaction progress: (1) diffusion of gas reactant through pores; (2) growth of product particle in pores; and (3) crack and spallation of solid reactant. The validation of this method has been conducted by comparison of results obtained in an experiment for oxidat

Total Mixed Ration (TMR), a system used in combining materials into feed for animals in the right proportion is a complex process especially when by-products are utilized. This involves several steps and unit machines. The current study focused on modeling a fermentation and storage system utilizing by-products for TMR feed production using the Arena V15 simulation program. Process time, operation rate, and bottleneck phenomenon were analyzed. The optimal capacities of unit machines were estimat

Non-uniformity of Pu and Cm composition in used nuclear fuel was analyzed to determine its effect on Pu accountancy in pyroprocessing, while employing the Pu-to-244Cm ratio method. Burnup simulation of a typical pressurized water reactor fuel assembly, required for the analysis, was carried out using MCNP code. Used fuel nuclide composition, as a function of nine axial and two radial meshes, were evaluated. The axial variation of neutron flux and self-shielding effects were found to affect the u

This study explores the potential for tritium production in North Korea's 5MWe graphite-moderated reactor, a facility primarily associated with nuclear weapons material production. While existing research on these reactors has largely centered on plutonium, our focus shifts to tritium, a crucial element in boosted fission bombs. Utilizing the MCNP6 code for simulations, the results estimate that North Korea can possibly produce approximately 7–12 g of tritium annually. This translates to the pot

A new methodology to analyze the nuclear material accountability for pyroprocessing system is developed. The Pu-to-244Cm ratio quantification is one of the methods for Pu accountancy in pyroprocessing. However, an uncertainty in the Pu-to-244Cm ratio due to the non-uniform composition in used fuel assemblies can affect the accountancy of Pu. A random variable, LOPu, is developed to analyze the probability of detection for Pu diversion of hypothetical scenarios at a pyroprocessing facility consid