核反应堆压力容器可靠性分析

本文介绍了反应堆压力容器可靠性的概率分析方法。其主要内容包括初始裂纹、裂纹扩展、载荷条件和物性参数等的概率分布.     

Coupled Ablation and Heat Transfer Analysis of Lower Head for Reactor Pressure Vessel under Severe Accident Condition

After a reactor core melts accident, the solid wall of the reactor pressure vessel (RPV) will be inevitably eroded by the melting core which contains large density of heat flux. The analysis of the coupled ablation and heat transfer of the lower head for RPV is of great theoretical significance to the effectiveness demonstration of water injection in reactor pit and the confirmation of the residual wall thickness of RPV. In this work, numerical simulations were carried out based on the RPV model of CPR1000 using the CFD software FLUENT 17.2. Based on dynamic mesh model and user-defined function (UDF) redevelopment, a fully coupling calculation model considering the transient ablation and heat conduction of solid wall of RPV, the redistribution of heat flux density in RPV inner wall and the subcooled boiling of RPV outer wall was established. Both two-phase flow pattern in the reactor pit and temperature field of RPV solid wall ablation within 9 000 s were obtained and the minimum residual wall thickness and the occurrence location were determined by analysis. The results show that it is feasible to use dynamic mesh to capture wall ablation. The fully coupling calculation model has certain advantages in analyzing the transient ablation process of RPV under severe accident.     

Detailed Evaluation of RCS Boundary Rupture during High-Pressure Severe Accident Sequences

A depressurization possibility of the reactor coolant system (RCS) before a reactor vessel rupture during a high-pressure severe accident sequence has been evaluated for the consideration of direct containment heating (DCH) and containment bypass. A total loss of feed water (TLOFW) and a station blackout (SBO) of the advanced power reactor 1400 (APR1400) has been evaluated from an initiating event to a creep rupture of the RCS boundary by using the SCDAP/RELAP5 computer code. In addition, intentional depressurization of the RCS using power-operated safety relief valves (POSRVs) has been evaluated. The SCDAPRELAP5 results have shown that the pressurizer surge line broke before the reactor vessel rupture failure, but a containment bypass did not occur because steam generator U tubes did not break. The intentional depressurization of the RCS using POSRV was effective for the DCH prevention at a reactor vessel rupture.     

反应堆压力容器法兰面沟槽尺寸参数对其金属O形环密封性能的影响

基于二维轴对称非线性弹塑性模型,对反应堆压力容器(RPV)用Inconel 718合金O形环进行了有限元分析,在试验验证的基础上探讨了筒体法兰面安装沟槽深度、沟槽间隙等关键参数对密封性能的影响。结果表明：镀银层对O形环的变形行为无实质影响,在进行有限元分析时可忽略镀银层;沟槽深度和沟槽间隙是影响O形环密封性能的关键参数,所涉及的RPV用金属O形环的最佳有效沟槽深度在(11±0.25) mm范围内、沟槽间隙取0.6 mm左右为宜。此外,O形环的安装和制造要求均极为苛刻,为保证O形环与沟槽间距的均匀性应严格控制好制造和安装等工序尺寸参数,从而提高密封性能。     

LOCA后物理现象对压力容器水位测量影响分析

为了验证CPR1000核电站冷却剂失流事故（LOCA）下堆芯冷却监测系统（CCMS）压力容器水位（L VSL）测量的有效性,对LOCA后影响动压和静压测量的物理现象,以及顶盖的特殊现象对L VSL测量引入的误差进行了量化计算。结果表明,顶盖的特殊现象和冷管段或热管段破口流量对L VSL测量引入的误差在破口发生几分钟后可忽略,压力容器顶部破口流量以及控制棒导向管内水的滞留对L VSL测量引入很大的高估误差,结合状态导向事故处理程序SOP的分析表明,该高估误差不会阻碍事故处理安全重要操作的执行。     

金矿封闭溶样法的优化

封闭溶矿体系由HNO3-NH4HF2-KMnO4-NaCl调整为HCl-NaClO3-NH4HF2,消除了传统封闭溶样法去除碳(包括石墨)、硫、碳酸盐等过程中可能出现的样品迸溅外溢、溶矿困难而导致分析测定结果偏低的不利因素,除硫速度和体系的反应体积易于控制,新生态[Cl]的产生速度和浓度大大增加,增加了反应容器内的压强值,进一步提高了矿石溶解效率,降低了对环境的污染程度。     

绕丝式超高压容器设计辅助系统

根据绕丝式超高压容器设计的特点,提出了容器筒体轻型化模糊优化数学模型,并利用Visual C 语言,开发了绕丝式超高压容器常规设计和模糊优化设计的计算机辅助设计系统,还利用实例对两种设计结果进行了对比.     

低焊接裂纹敏感性WDL系列钢的力学性能及组织结构

研究了低焊接裂纹敏感性０７ＭｎＣｒＭｏＶ系列钢的力学性能和组织结构。结果表明：该钢具有优异的焊接性能和低温韧性；板厚≤５０ｍｍ的钢板焊前不预热或稍加预热而不产生焊接冷裂纹，是制造大型压力容器、水电站压力钢管和水轮机蜗壳，高寒地区使用的大型工程机械、大跨度桥梁及海上采油平台等装备的理想用材。     

立式压力容器腿式支座计算

介绍了立式压力容器的腿式支座计算,解决了超出标准范围的立式压力容器的腿式支座选用及计算的问题。     

ICA1L Is Associated with Small Vessel Disease: A Proteome-Wide Association Study in Small Vessel Stroke and Intracerebral Haemorrhage

Small vessel strokes (SVS) and intracerebral haemorrhages (ICH) are acute outcomes of cerebral small vessel disease (SVD). Genetic studies combining both phenotypes have identified three loci associated with both traits. However, the genetic cis-regulation at the protein level associated with SVD has not been studied before. We performed a proteome-wide association study (PWAS) using FUSION to integrate a genome-wide association study (GWAS) and brain proteomic data to discover the common mechanisms regulating both SVS and ICH. Dorsolateral prefrontal cortex (dPFC) brain proteomes from the ROS/MAP study (N = 376 subjects and 1443 proteins) and the summary statistics for the SVS GWAS from the MEGASTROKE study (N = 237,511) and multi-trait analysis of GWAS (MTAG)-ICH–SVS from Chung et al. (N = 240,269) were selected. We performed PWAS and then a co-localization analysis with COLOC. The significant and nominal results were validated using a replication dPFC proteome (N = 152). The replicated results (q-value < 0.05) were further investigated for the causality relationship using summary data-based Mendelian randomization (SMR). One protein (ICA1L) was significantly associated with SVS (z-score = −4.42 and p-value = 9.6 × 10⁻⁶) and non-lobar ICH (z-score = −4.8 and p-value = 1.58 × 10⁻⁶) in the discovery PWAS, with a high co-localization posterior probability of 4. In the validation PWAS, ICA1L remained significantly associated with both traits. The SMR results for ICA1L indicated a causal association of protein expression levels in the brain with SVS (p-value = 3.66 × 10⁻⁵) and non-lobar ICH (p-value = 1.81 × 10⁻⁵). Our results show that the association of ICA1L with SVS and non-lobar ICH is conditioned by the cis-regulation of its protein levels in the brain.