Analysis of containment pressure control strategy in HPR1000 NPP under severe accidents

Containment is the last barrier of preventing the release of radioactive fission products in a nuclear power plant (NPP). It has the top priority of its strategy in a severe accident (SA) to ensure the integrity of containment. Generally, there are two ways for the containment heat removal. One is to set exchangers or sprays to cool the atmosphere in the containment like CPR1000. The other is to set sprays out of the steel containment to remove heat like AP1000. After Fukushima Daiichi nuclear accident, mitigation strategies after severe accidents are focused and specific systems of dealing with containment failure threat are required to design in new built NPPs. HPR1000 is a generation-Ⅲ PWR in China, which deployed the dedicated severe accident (SA) system of containment spray to address the above conditions. Containment spray in HPR1000 has two identical trains isolated physically, and each train is capable to reduce containment pressure after severe accidents. The containment spray system cannot start automatically, but only be started by operator during severe accidents. According to the lessons from Fukushima accident, it is hard for the operator to make the right choice in such a high-pressure environment during severe accidents, so the proper start-up time is better given in advance as possible. This paper assesses the effectiveness of the containment spray, conducts sensitive calculations of different start-up time, and discuss the negative effects of containment spray. Based on the calculation results, insights of containment spray strategy are gained for HPR1000 NPP and the proper start-up time for the strategy of containment spray in SAMG are put forward

The Paradoxical Effect Hypothesis of Abused Drugs in a Rat Model of Chronic Morphine Administration

A growing body of studies has recently shown that abused drugs could simultaneously induce the paradoxical effect in reward and aversion to influence drug addiction. However, whether morphine induces reward and aversion, and which neural substrates are involved in morphine’s reward and aversion remains unclear. The present study first examined which doses of morphine can simultaneously produce reward in conditioned place preference (CPP) and aversion in conditioned taste aversion (CTA) in rats. Furthermore, the aversive dose of morphine was determined. Moreover, using the aversive dose of 10 mg/kg morphine tested plasma corticosterone (CORT) levels and examined which neural substrates were involved in the aversive morphine-induced CTA on conditioning, extinction, and reinstatement. Further, we analyzed c-Fos and p-ERK expression to demonstrate the paradoxical effect—reward and aversion and nonhomeostasis or disturbance by morphine-induced CTA. The results showed that a dose of more than 20 mg/kg morphine simultaneously induced reward in CPP and aversion in CTA. A dose of 10 mg/kg morphine only induced the aversive CTA, and it produced higher plasma CORT levels in conditioning and reacquisition but not extinction. High plasma CORT secretions by 10 mg/kg morphine-induced CTA most likely resulted from stress-related aversion but were not a rewarding property of morphine. For assessments of c-Fos and p-ERK expression, the cingulate cortex 1 (Cg1), prelimbic cortex (PrL), infralimbic cortex (IL), basolateral amygdala (BLA), nucleus accumbens (NAc), and dentate gyrus (DG) were involved in the morphine-induced CTA, and resulted from the aversive effect of morphine on conditioning and reinstatement. The c-Fos data showed fewer neural substrates (e.g., PrL, IL, and LH) on extinction to be hyperactive. In the context of previous drug addiction data, the evidence suggests that morphine injections may induce hyperactivity in many neural substrates, which mediate reward and/or aversion due to disturbance and nonhomeostasis in the brain. The results support the paradoxical effect hypothesis of abused drugs. Insight from the findings could be used in the clinical treatment of drug addiction

Efficacy of scalp acupuncture combined with conventional therapy in the intervention of post-stroke depression: A systematic review and meta-analysis

Background: Post-stroke depression (PSD) is a common complication following a stroke, significantly impacting patients' quality of life and mental well-being. Currently, two primary approaches are employed to treat PSD: drug therapy and non-drug therapy. Among these, acupuncture, specifically scalp acupuncture (SA), has gained attention due to its cost-effectiveness and broad social benefits. SA is a precise and direct form of acupuncture that has been utilized in the treatment of PSD. Although several randomized controlled trials (RCTs) have demonstrated the efficacy of SA in treating PSD, there is a lack of comprehensive systematic reviews. Given the limitations of existing evidence, we conducted a systematic evaluation to assess the effectiveness of SA in combination with conventional therapy (CT) for intervening in PSD. Methods: We systematically searched five databases for articles published up until May 31, 2023, pertaining to SA treatment of PSD. A team of researchers meticulously screened and assessed these articles to identify the final included studies. After extracting relevant information and outcome indicators from the selected articles, we employed RevMan5.3 software to evaluate their quality and perform statistical analysis. Throughout our research, we strictly adhered to the PRISMA 2020 guidelines. Results: A total of 11 articles were included, and a meta-analysis was conducted to evaluate the effectiveness of SA combined with CT for treating PSD. The results revealed that SA combined with CT can effectively improve the treatment's success rate for PSD and reduce the severity of depressive symptoms measured by the Self-Rating Depression Scale. However, SA combined with CT did not show significant reductions in depressive symptoms assessed by the Hamilton Rating Scale for Depression, which may be related to the inclusion of high heterogeneity articles. Importantly, the combination treatment did not lead to an increase in adverse reactions among PSD patients. Conclusion: While the effectiveness of SA combined with CT in treating PSD still requires further validation through rigorous randomized double-blind trials, this study provides a comprehensive collection of studies that meet the criteria for SA combined with CT in PSD treatment. It objectively and systematically evaluated the impact of SA combined with CT on PSD. Consequently, the findings of this study hold certain clinical significance

Knowledge mapping of nano drug delivery systems across blood - Brain barrier from 1996 to 2022: A bibliometric analysis

Background: The blood-brain barrier (BBB) is a natural physiological barrier that protects the central nervous system from foreign substances and limits the delivery of drugs to the brain. Nanotechnology has opened up new possibilities for drug delivery in the brain. Over several decades, various Nanoparticle Drug Delivery Systems (NDDS) that can cross the BBB have been developed for targeted delivery in the brain. To gain a comprehensive understanding of the current research hotspots and trends of NDDS across the BBB, this paper employs bibliometric analysis of articles published in the core database of Web of Science (WOS) from 1996 to 2022. Method: A search for relevant research literature on NDDS that can cross the BBB was conducted in the Web of Science database, covering the period from 1996 to 2022. The Bibliometrix R-4.0 software package was used to analyze data related to the countries of publication, research institutions, journals, citations, and keywords. The analysis aimed to identify the co-occurrence of keywords in the documents, including their titles and abstracts. Additionally, cooperative network analyses of authors, institutions, and countries of publication were conducted. Results: A total of 436 articles were analyzed, originating from 174 journals and 13 books, with the majority published in Q1 and Q2 journals. Contributors from 53 countries or regions participated in the publication of these articles, with China, the United States, and India having the highest number of articles by correspondent authors, and China, the United States, and Germany being the most cited countries. Fudan University, Hacettepe University, and Sichuan University were the top three institutions with the most publications. Among the 436 articles analyzed, 1337 keywords and 1450 keywords plus were identified. Factor analysis grouped the keywords plus into two categories: drug delivery systems, polymeric nanoparticles, gold nanoparticles, transferrin, and others, and drug, delivery, efficiency, expression, and mechanism. Conclusion: The research on NDDS that can cross the BBB is gradually receiving attention, and the recognition and cooperation in this field have increased

Uncertainty quantification for a severe accident sequence in a SFP in the frame of the H-2020 project MUSA: First outcomes

International audienceThe Management and Uncertainties of Severe Accidents (MUSA) project, funded in HORIZON 2020 and coordinated by CIEMAT (Spain), aims at consolidating a harmonized approach for the analysis of uncertainties and sensitivities associated with Severe Accidents (SAs) focusing on Source Term (ST). In this framework, the objectives of the Innovative Management of Spent Fuel Pool Accidents (IMSFP – WP6), led by IRSN (France), are to quantify and rank the uncertainties affecting accident analyses in a Spent Fuel Pool (SFP), to review existing and contemplated SA management measures and systems and to assess their possible benefits in terms of reduction of radiological onsequences.To quantify the propagation of the uncertainties of the input parameters to the output uncertainties of severe accident codes (ASTEC, MELCOR, RELAP/SCDAP), a diverse set of uncertainty quantification (UQ) tools (DAKOTA, RAVEN, SUNSET, SUSA) are used. The statistical framework used by the different UQ-tools is similar e.g. pure random (Monte Carlo) and Latin hypercube sampling (LHS).Fourteen partners from three different world regions are involved in the WP6 activities. The target of this paper is to describe the achievements during the first three years ofthe project. In a first part, a description is given of the SFP accidental scenario, of the key target variables and radionuclides chosen as ST Figure of Merits (FoM) and of theidentified uncertainty sources in models and input parameters. A key element when defining the SFP scenario has been the consideration (or not) of the reactor building,as it is expected to significantly affect analyses. In a second part, the first insights coming out from the calculation phase of the project are presented. The review of existing SA management measures is also exposed, as well as systems whose benefits will be assessed in the second phase of the project. Finally, challenges that arise from such an exercise are discussed, as well as major difficulties found when applying UQ methodologies to SFP scenarios and solutions adopted

First Outcomes from the PHEBUS FPT1 Uncertainty Application done in the EU-MUSA Project

The Management and Uncertainties of Severe Accidents (MUSA) project, founded in HORIZON 2020 and coordinated by CIEMAT (Spain), aims to consolidate a harmonized approach for the analysis of uncertainties and sensitivities associated with Severe Accidents (SAs) by focusing on Source Term (ST) Figure of Merits (FOM). In this framework, among the 7 MUSA WPs the Application of Uncertainty Quantification (UQ) Methods against Integral Experiments (AUQMIE – Work Package 4 (WP4)), led by ENEA (Italy), looked at applying and testing UQ methodologies, against the internationally recognized PHEBUS FPT1 test. Considering that FPT1 is a simplified but representative SA scenario, the main target of the WP4 is to train project partners to perform UQ for SA analyses. WP4 is also a collaborative platform for highlighting and discussing results and issues arising from the application of UQ methodologies, already used for design basis accidents, and in MUSA for SA analyses. As a consequence, WP4 application creates the technical background useful for the full plant and spent fuel pool applications planned along the MUSA project, and it also gives a first contribution for MUSA best practices and lessons learned. 16 partners from different world regions are involved in the WP4 activities. The purpose of this paper is to describe the MUSA PHEBUS FPT1 uncertainty application exercise, the methodologies used by the partners to perform the UQ exercise, and the first insights coming out from the calculation phase