This study examined the effects of pre-soaking solvents and repeated steaming-drying (SD) cycles on the antioxidant activity and active compound content of Rehmanniae Radix Preparata(RRP), the processed root of Rehmannia glutinosa Libosch. SD treatments were conducted for 1 to 9 cycles using four different pre-soaking solvents: Takju (a traditional rice wine), Spirits, Honey, and Sugar solution. The results showed no significant differences in DPPH and ABTS radical scavenging activities or in total polyphenol and flavonoid contents among the pre-soaking treatments, although samples pre-soaked in honey and Takju exhibited slightly higher levels. Polyphenol and flavonoid contents increased progressively with the number of SD cycles, reaching levels 2–3 times higher after nine cycles. Catalpol content remained relatively constant regardless of treatment, whereas aucubin content increased in all groups, with the highest accumulation observed in the Takju treatment. Similarly, 5-hydroxymethylfurfural (5-HMF) content increased with the number of SD cycles, with the highest levels found in the honey group, followed by Takju, Sugar, and Spirits. In conclusion, while the type of pre-soaking solvent had minimal influence on antioxidant activities and catalpol content, both aucubin and 5-HMF contents increased with additional SD cycles, with Takju proving particularly effective in enhancing their accumulation.

The decommissioning of nuclear power plants will generate a lot of low and intermediate-level radioactive waste (LILW), and preliminary radioactive evaluation for these wastes should be carried out before decommissioning work. Mainly, Concrete, Carbon Steel, Stainless Steel-304 (SS304) and Inconel are used in many parts of nuclear power plants and considered as main resource of nuclear wastes. Depending on the material location, the number of neutrons irradiated to material varies, which can range from self-disposal waste to LILW. In this paper, activation analysis was performed to compare the radiation dose according to the presence or absence of impurity elements present in SS304. For the calculation, SS304 composition and impurity elements were used as described in the report of NUREG-3474. This report lists 41 impurity elements for SS304 and other materials. Calculation code is used ORIGEN-S module in SCALE 6.1 code. Neutron flux is used as arbitrary value that around 1E+11 level and irradiation time is set as 30 year with 10-year cooling time. In the ORIGEN-S calculation, 1g of SS304 is used for easy calculation of specific activity. The ORIGEN-S calculation results are as follows. All impurity elements contained case calculated 9.32E+07 Bq activity. In the absence of all impurity elements case and most cases shows that total Becquerel value after 10-year cooling time around 9.11E+07 Bq, and Co impurity case had larger result. The calculation was performed again by increasing the amount of impurity substances by 100 times to perform the sensitivity evaluation more reliably. Representatively, Li, N, Co, and Ba impurity elements cases were calculated to have a particularly high Becquerel. Especially Co impurity element case, a total Becquerel of 3.03E+08 was calculated. Accordingly, evaluation of impurities mixed in SS304 must be considered, and in particular, the inclusion rate for Co must be considered.

Self-Powered Neutron Detector (SPND) is one of devices for in-core fluxes detecting without external electricity source. SPND consisted with emitter, insulator and collector. When neutrons reacted with emitter material, it generates electrons and these electrons cross insulator area to make electric signal in collector area. For calculating sensitivity of SPND with Monte-Carlo code such as MCNP, many physical components must be considered. Cobalt shows that prompt signal and relatively low signal comparing with other delayed signal SPNDs. Initial sensitivity was calculated as 4.28×10−22 A/nv-cm for one electron. Due to Cobalt’s complex decay chain and maintaining high efficiency of SPND, it is necessary to analysis the effect of activation of emitter. Therefore, the DPA (Displacements Per Atom) assessment and activation analysis of the detector components have been evaluated with MCNP 6.2 and ORIGEN-S. With these activation analysis results, that is expected to be used to determine the shielding thickness of the storage system.