A novel approach on designing ultrahigh burnup metallic TWR fuels: Upsetting the current technological limits.

Abstract: The grand challenge of "net-zero carbon" emission calls for technological breakthroughs in energy production. The traveling wave reactor (TWR) is designed to provide economical and safe nuclear power and solve imminent problems, including limited uranium resources and radiotoxicity burdens from back-end fuel reprocessing/disposal. However, qualification of fuels and materials for TWR remains challenging and it sets an "end of the road" mark on the route of R&D of this technology. In this article, a novel approach is proposed to maneuver reactor operations and utilize high-temperature transients to mitigate the challenges raised by envisioned TWR service environment. Annular U-50Zr fuel and oxidation dispersion strengthened (ODS) steels are proposed to be used instead of the current U-10Zr and HT-9 ferritic/martensitic steels. In addition, irradiation-accelerated transport of Mn and Cr to the cladding surface to form a protective oxide layer as a self-repairing mechanism was discovered and is believed capable of mitigating long-term corrosion. This work represents an attempt to disruptively overcome current technological limits in the TWR fuels. Impact statement: After the Fukushima accident in 2011, the entire nuclear industry calls for a major technological breakthrough that addresses the following three fundamental issues: (1) Reducing spent nuclear fuel reprocessing demands, (2) reducing the probability of a severe accident, and (3) reducing the energy production cost per kilowatt-hour. An inherently safe and ultralong life fast neutron reactor fuel form can be such one stone that kills the three birds. In light of the recent development findings on U-50Zr fuels, we hereby propose a disruptive, conceptual metallic fuel design that can serve the following purposes at the same time: (1) Reaching ultrahigh burnup of above 40% FIMA, (2) possessing strong inherent safety features, and (3) extending current limits on fast neutron irradiation dose to be far beyond 200 dpa. We believe that this technology will be able to bring about revolutionary changes to the nuclear industry by significantly lowering the operational costs as well as improving the reactor system safety to a large extent. Supplementary information: The online version contains supplementary material available at 10.1557/s43577-022-00420-4.

Effects of body parameters on renal cortical stiffness measured by shear-wave elastography in patients with kidney transplantation. / 人体参数对剪切波弹性成像定量移植肾皮质硬度的影响.

OBJECTIVES: The results of elastic imaging in evaluating the function and histopathological changes of allogeneic renal transplantation are contradictory, one of the important reasons may be that there are differences in human parameters related to kidney transplantation among individuals. The purpose of this study is to explore the related human body parameters on shear-wave elastography (SWE) effects on quantitative stiffness of graft cortex. METHODS: From March 2021 to November 2021, a total of 63 patients with allogeneic kidney transplantation in the Department of Ultrasonography, Third Xiangya Hospital, Central South University, were selected to collect the parameters of two-dimensional, color Doppler and SWE. The subjects were divided into a <20% group and a 20%-30% group according to the variation of cortical hardness measurement. Mann Whitney U test was used to compare the differences in relevant human parameters, and Spearman rank correlation was used to analyze the correlation between relevant human parameters and cortical hardness of transplanted kidney. RESULTS: There was no significant difference between the 2 groups in age, sex, postoperative time, resistance index of interlobar artery, SCr, blood uric acid, ratio of fat layer to muscle layer, and BMI (all P>0.05). Compared with the <20% group, the patients in the 20%-30% group had smaller cortical hardness of the transplanted kidney, greater total distance between the transplanted kidney and the skin surface, and thicker fat layer or muscle layer in front of the transplanted kidney (all P<0.05). The age of patients, the total distance from the transplanted kidney to the skin surface, the thickness of fat layer and muscle layer, the ratio of fat layer to muscle layer, BMI, and the variation of cortical hardness were significantly negatively correlated with the cortical hardness of the transplanted kidney (all P<0.05). CONCLUSIONS: Human parameters relevant to kidney transplantation affect the accuracy of SWE in measuring the cortical hardness of the transplanted kidney. It is very important to obtain the highly stabile elastic measurement value and interpret the elastic measurement results according to different levels of human body related parameters in combination with individual conditions.

Hydrotubation combined with chinese herbal medicine for salpingitic infecundity: a systematic review and meta-analysis.

Salpingitis is a major cause of infertility. Clinical studies about hydrotubation combined with Chinese herbal medicine (CHM) for salpingitic infecundity are increasing, while systematic reviews about its efficacy remain inexistent. Assessing the effectiveness of hydrotubation combined with CHM for salpingitic infecundity. Randomized controlled trials were retrieved from different seven databases. One thousand three hundred and thirty-seven papers were collected and only 16 randomized clinical trials met the requirements and were included. The meta-analysis indicated that hydrotubation combined with CHM was associated with a higher pregnancy rate and a lower ectopic pregnancy rate compared to hydrotubation alone. The success rate of recanalization was significantly increased, as well as signs and symptoms were better alleviated in patients treated with hydrotubation combined with CHM. The clinical data available indicate that compared with hydrotubation alone, hydrotubation combined with CHM for salpingitic infecundity has better therapeutic effects.

Spatial distribution of hazardous elements in urban topsoils surrounding Xi'an industrial areas, (NW, China): controlling factors and contamination assessments.

Understanding of the hazardous in urban soil and their anthropogenic effect from urban industrial areas is important for urban environmental management and protection. In this study, a total of 44 soil samples were collected from Xi'an western industrial areas, NW, China, and the concentrations of 29 elements were measured by wavelength dispersive X-ray fluorescence (WDXRF) spectrometry. The sources of hazardous metals were conducted through multivariate statistical methods (principal component analysis, clustering analysis, and correlation analysis). The dangerous metals' influences on the environment were evaluated from Nemero Synthesis Index Method and Geostatistical Analysis. All the results indicated the multivariate statistical methods had successfully classified three factors of heavy metals from different sources, of which 36.40% accounted for industrial activities and exhaust emissions, 32.09% for agricultural as well as the precipitant of gas stream, and 31.51% for coal combustion factor. Through the pollution evaluation and the further spatial analysis, the hazardous metals distributed consistently with prevailing NW-SE local wind direction, strongly polluted the urban soil and potentially affected environmental quality and health of Xi'an urban city, especially Bi, Pb, Zn, Sb, and Sn. The results advocated the future tactics for Xi'an environment quality control on a local scale had to concern not only the levels of hazardous but also the industrial emission abatement techniques and urban setting and plan.