核技术
覈技術
핵기술
Nuclear Techniques
2015年
9期
090605-1-090605-6
,共1页
概率安全分析%安全壳内置换料水箱子系统%堆芯损坏频率
概率安全分析%安全殼內置換料水箱子繫統%堆芯損壞頻率
개솔안전분석%안전각내치환료수상자계통%퇴심손배빈솔
PSA%IRWST sub-system%CDF
根据一级概率安全分析(Probabilistic Safety Analysis, PSA)的结果，安全壳内置换料水箱(In-containment Refueling Water Storage Tank, IRWST)子系统的初始设计导致安注管线破裂(Safety Injection Line Break, SI-LB)始发事件对堆芯损坏频率(Core Damage Frequency, CDF)有较大的贡献。本文提出了 IRWST 子系统的设计改进方案，将 IRWST 水箱内的滤网由两个(A/B)增加为三个(A/B/C)，并通过管线实现滤网之间的相互连接。通过重新构建故障树对改进后的 IRWST 子系统进行建模分析，并对相应的事件树以及一级 PSA 模型进行详细的定量化计算。结果表明，IRWST 子系统这一改进能够显著降低堆芯损坏风险。IRWST 子系统的改进将 SI-LB始发事件的 CDF 降低了53.5%，将整个一级 PSA 的 CDF 降低了21.5%。
根據一級概率安全分析(Probabilistic Safety Analysis, PSA)的結果，安全殼內置換料水箱(In-containment Refueling Water Storage Tank, IRWST)子繫統的初始設計導緻安註管線破裂(Safety Injection Line Break, SI-LB)始髮事件對堆芯損壞頻率(Core Damage Frequency, CDF)有較大的貢獻。本文提齣瞭 IRWST 子繫統的設計改進方案，將 IRWST 水箱內的濾網由兩箇(A/B)增加為三箇(A/B/C)，併通過管線實現濾網之間的相互連接。通過重新構建故障樹對改進後的 IRWST 子繫統進行建模分析，併對相應的事件樹以及一級 PSA 模型進行詳細的定量化計算。結果錶明，IRWST 子繫統這一改進能夠顯著降低堆芯損壞風險。IRWST 子繫統的改進將 SI-LB始髮事件的 CDF 降低瞭53.5%，將整箇一級 PSA 的 CDF 降低瞭21.5%。
근거일급개솔안전분석(Probabilistic Safety Analysis, PSA)적결과，안전각내치환료수상(In-containment Refueling Water Storage Tank, IRWST)자계통적초시설계도치안주관선파렬(Safety Injection Line Break, SI-LB)시발사건대퇴심손배빈솔(Core Damage Frequency, CDF)유교대적공헌。본문제출료 IRWST 자계통적설계개진방안，장 IRWST 수상내적려망유량개(A/B)증가위삼개(A/B/C)，병통과관선실현려망지간적상호련접。통과중신구건고장수대개진후적 IRWST 자계통진행건모분석，병대상응적사건수이급일급 PSA 모형진행상세적정양화계산。결과표명，IRWST 자계통저일개진능구현저강저퇴심손배풍험。IRWST 자계통적개진장 SI-LB시발사건적 CDF 강저료53.5%，장정개일급 PSA 적 CDF 강저료21.5%。
Background: Probabilistic safety analysis (PSA) methodology is widely used to assess the risk of nuclear power plant (NPP). Based on the results of level 1 PSA, the vulnerability of In-containment Refueling Water Storage Tank (IRWST) sub-system makes the initiating event Safety Injection Line Break (SI-LB) contributing significantly to core damage frequency (CDF). Purpose: This study aims to find the vulnerability of IRWST design by PSA assessment, and provide design improvement suggestion to reduce the risk of NPP. Methods: PSA methodology is used to evaluate the design improvement of IRWST, which is implemented by adding a third strainer (strainer C), and the three strainers are connected to each other. Fault trees of IRWST are rebuilt, and related event trees and level 1 PSA model are recalculated. Results: Quantitative result shows that the contribution of SI-LB initiating event to CDF is reduced by 53.5% and the total CDF is reduced by 21.5%. Conclusion: Design improvement of IRWST sub-system greatly reduced the core damage risk.
