Suchergebnisse

Reactor pressure vessel (RPV) support is a key safety facility which is categorized as Class 1 in the ASME nuclear safety design. The temperature distribution of RPV support is one of the key considerations for the concrete safety contacting with the bottom of the support. So it is necessary for accurate evaluation on the temperature field characteristics of RPV support, especially the bottom of support. This paper investigates the temperature field characteristics of modified RPV support which will be applied to a large advanced pressurized water reactor. A support entity is manufactured in a ratio of 1:1, and its temperature distribution is measured under simulated reactor operating conditions. Numerical simulation is also used to validate the results by the developed CFD model. The results show that under the operating conditions, of which the inlet cooling air temperature is 35.35°C and the velocity is 6.25 m/s, the temperature distribution of modified RPV support bottom is uneven, and the highest temperature is around 38°C, which is much lower than the demanding design temperature 93.3°C. Therefore, the design of the modified RPV support is reliable. In addition, the results of numerical simulation agree well with the experimental results with the error less than ±4°C, which ensures the reliability of the conclusion. The effects of inlet cooling air temperature and velocity on the RPV support temperature distribution are further studied. Both the temperature decrease and velocity increase can reduce the RPV support temperature. But the effect of inlet cooling air temperature is more obvious than inlet cooling air velocity. So the best way to improve air cooling capacity is to decrease the support inlet cooling air temperature. The results can provide a good guidance to the design of RPV support for the subsequent large advanced pressurized water reactor.

BACKGROUND: In 2016, the government of Bao'an District, Shenzhen, China launched a free medication program for all non-registered permanent residents with severe mental disorders (SMD) within its jurisdiction, in efforts to reduce the relapse caused by intermittent medication or non-medication. Participation in the program has not been analyzed since its inauguration. This study aimed to evaluate the participation of non-registered permanent residents with SMD in the program from 2016 to 2020 and to explore its influencing factors. METHODS: This is a retrospective cross-sectional study of 3760 non-registered permanent residents with SMD in Bao'an District, Shenzhen, China (response rate: 78.64%). Data have been obtained from two sources: the Shenzhen Information System for Psychosis in 2020 and the free medication program's management files from 2016 to 2020. We employ descriptive statistics to analyze the participation rate of the free medication program among non-registered permanent patients. Logistic regression analysis is used to explore the factors affecting the patients' participation in the program. RESULTS: The participation rate of the free medication program among non-registered permanent patients has shown an upward trend, rising from 28.83% in 2016 to 58.32% in 2020. High participation rates have been registered among the following patient subgroups: those aged between 30 and 39 (63.11%), those with high school/technical secondary school (62.33%), those from rural areas (61.62%), those living in poverty (67.79%), those suffering schizoaffective disorder (72.26%), those having SMD for less than 5 years (59.89%), and those with family history of mental illness (71.23%).Logistics regression analysis shows that age, patient-guardian relationship, place of residence, financial condition, types of disease, duration of illness and family history are the main factors affecting the patients' decision to participate in the free medication program. CONCLUSION: The steadily increasing participation rate of the ...