核电厂严重事故下仪表可用性评价方法研究

发布时间：2018-07-07 21:35

本文选题：核电厂 + 仪表　；参考：《南华大学》2014年硕士论文

【摘要】：对核电厂严重事故下的仪表进行可用性评价，主要目的是通过分析和证明，确定用于缓解和监测严重事故进程的仪表能以合理的可信度确保其在要求的时间内的有效性，以确保在核电厂发生严重事故时能够正确获取电厂状态。同时，其可用性评价结果可用于核电厂严重事故管理导则的制定工作，对于核电厂严重事故的管理有着重大意义。目前国际上严重事故条件下仪表可用性分析相关的标准体系并未完全建立，但核电厂严重事故管理的相关安全法规均明确要求必须证明用于缓解严重事故的仪表及设备在事故条件下可用。因此需要针对严重事故环境特点，对仪表可用性评价方法展开研究。本文研究内容主要分为以下三个方面：一．通过对严重事故管理以及仪表质量鉴定相关法规及标准进行分析，明确了严重事故下仪表评价的要求及方向。同时对严重事故环境条件及其对仪表的影响因素展开研究，明确了严重事故下仪表可用性评价要素。同时针对现有的评价的不足之处，探讨并研究了鉴定曲线包络法及电路仿真法，并形成了综合运用两种评价方法的完整评价流程。二．基于鉴定曲线包络法，对目前的主流压水堆核电厂进行了严重事故下仪表可用性评价。在评价过程中，将仪表鉴定时的环境条件曲线与严重事故的环境条件曲线进行包络对比，结合分析仪表环境敏感因素，评价仪表的性能在严重事故条件下是否受到影响。在给出了部分评价结果的同时，对评价方法的可信度和适用范围进行了探讨。三．基于电路仿真法，对鉴定曲线包络法无法准确判断可用性的仪表进行了进一步的研究和分析。在该方法评价过程中，针对仪表电路特点建立简化的等效电路模型，并根据严重事故环境对其影响特征建立降级的电路特征，最后利用电路仿真软件计算其在各环境下的输出波形，并根据一定判据将仪表的可用性分为可用、降级可用及不可用三类。最后通过将具体仪表的评价结果同三里岛事故后仪表可用性检验报告进行了对比，验证了该方法的合理性及可信度。本研究为严重事故下仪表可用性评价提供了较好的思路和较为完整的方法。具有一定的前瞻性，，同时具有很好的实际应用价值。
[Abstract]:The main purpose of assessing the availability of instruments in the event of serious accidents in nuclear power plants is to determine, through analysis and proof, that the instruments used to mitigate and monitor the process of serious accidents can ensure their effectiveness within the required time with reasonable credibility, To ensure that the power plant state can be correctly obtained in the event of a serious accident in the nuclear power plant. At the same time, the results of usability evaluation can be used in the formulation of guidelines for the management of serious accidents in nuclear power plants, which is of great significance to the management of serious accidents in nuclear power plants. At present, the international standard system related to instrument availability analysis under serious accident conditions has not been fully established. However, the relevant safety regulations for the management of serious accidents in nuclear power plants require that the instruments and equipment used to mitigate the serious accidents must be proved to be available under the accident conditions. Therefore, it is necessary to study the instrument availability evaluation method according to the characteristics of serious accident environment. The research content of this paper is divided into the following three aspects: 1. Through the analysis of the regulations and standards related to the management of serious accidents and the identification of instrument quality, the requirements and direction of instrument evaluation under serious accidents are clarified. At the same time, the environmental conditions of serious accidents and their influencing factors on instrumentation are studied, and the evaluation elements of instrument availability under serious accidents are defined. At the same time, aiming at the shortcomings of the existing evaluation, the paper discusses and studies the envelope method of the appraisal curve and the circuit simulation method, and forms a complete evaluation flow using the two evaluation methods synthetically. 2. Based on the evaluation curve envelope method, the instrument availability of the current mainstream PWR nuclear power plant is evaluated under serious accidents. In the process of evaluation, the environmental condition curve of instrument identification is compared with the environmental condition curve of serious accident, and the performance of instrument is evaluated under the condition of serious accident by analyzing the sensitive factors of instrument environment. At the same time, the reliability and application range of the evaluation method are discussed. 3. Based on the circuit simulation method, further research and analysis are carried out on the instruments whose availability can not be judged accurately by the envelope method of the identification curve. In the evaluation process of this method, the simplified equivalent circuit model is established according to the characteristics of the instrument circuit, and the downgrade circuit characteristics are established according to the influence characteristics of the serious accident environment. Finally, the output waveform of the instrument is calculated by using the circuit simulation software, and the availability of the instrument is divided into three categories according to certain criteria: availability, demotion, availability and unavailability. Finally, the rationality and reliability of the method are verified by comparing the evaluation results of the specific instruments with the instrument availability test report after the accident in San Mile Island. This research provides a good idea and a more complete method for instrument usability evaluation under serious accident. Has certain foresight, at the same time has the very good practical application value.
【学位授予单位】：南华大学
【学位级别】：硕士
【学位授予年份】：2014
【分类号】：TM623

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