核电厂设计瞬态清单及假设确定方法研究

Methods for Determining the Design Transient List of Nuclear Power Plants and its Assumptions

设计瞬态清单是设计阶段开展设备疲劳和力学评价的基础,也是运行期间核电厂对机械设备性能评估和延寿的依据。设计瞬态清单包括设计瞬态条目和设计瞬态次数两部分。本文基于调研典型压水堆设计瞬态清单和设计工况清单的差别,提出设计瞬态清单的总体设计要求,即应具备全面性和包络性。之后分别分析了正常运行工况,以及扰动、应急、事故工况设计瞬态清单的制定方法。此外,部分设计瞬态工况具体假设应考虑力学评价的保守性以及电厂瞬变统计的便利性,对个别非典型瞬态过程采取包络性的简化处理,在本文中以示例方式给出解释。本文所述方法对核电厂设计瞬态清单制定提供了总体思路,可供实践参考和进一步研究。

The design transient list is the basis for fatigue and mechanics valuation of equipment during nuclear power plants’design phase,and the basis for performance evaluation and life extension of mechanical equipment during NPPs’operation phase.The design transient list includes two parts:design transient conditions and occurrence number of each condition.Based on difference between the design condition list and design transient list,this paper explained the main method of determining the design transient list of nuclear power plants.Design transient conditions are derived from grouping postulated initial events(PIEs)from different punishment mechanism aspects.In addition,some simplified assumption is adopted considering the conservatism of mechanical valuation and the convenience of plant transient statistics.The method described in this paper provides a general idea for the determination of the NPP design transient list,which can be used for practical reference and further study.