Current summary of international extreme load design requirements for nuclear power plant facilities

Abstract As states in the IAEA SSR-2/1 (Rev.1) and IAEA TECDOC-1791, the defence in depth concept is not to be understood as merely limited to the request for the implementation of a number of consecutive barriers and protection levels, but is to be understood as the main general principle that leads to the formulation of safety requirements including requirements necessary to achieve the quality and reliability expected for the barriers and for systems ensuring their integrity. Thus, the application of defence in depth concept is not only limited in the reactor core design, but also can extend to a wider range in nuclear power plant design. In this paper, the application of defence in depth concept, which is defined in IAEA latest requirements, in the irradiated fuel water pool storage, electrical system, internal hazards and external hazards of the nuclear power plant design are reviewed. Base on the study of the newest standard and codes, the design requirements of each level of defence in depth in the above systems are confirmed. The analysis of defence in depth design features of an advanced nuclear power plant in China are also show the application value of defence in depth in these extended regions.

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Failure Probability of NPP Communication Bridge under the Extreme Loads

Applied Mechanics and Materials ◽

10.4028/www.scientific.net/amm.617.81 ◽

2014 ◽

Vol 617 ◽

pp. 81-85 ◽

Cited By ~ 6

Author(s):

Juraj Králik ◽

Juraj Kralik

Keyword(s):

Power Plant ◽

Nuclear Power Plant ◽

Nuclear Power ◽

Input Data ◽

Steel Bridge ◽

Advantages And Disadvantages ◽

Extreme Loads ◽

Load Factors ◽

Extreme Load ◽

Safety And Reliability

Safety and reliability of the communication steel bridge of the nuclear power plant under extreme loads is considered in this paper. The extreme load from the wind and the earthquake is defined for the probability of exceedance 10-4 per year on the base of the last results from the investigation in Slovakia. The deterministic and the probabilistic assessments to verify the safety and reliability of the structure are presented. The uncertainties of the input data and the calibration of the load factors are discussed. The advantages and disadvantages of the probabilistic analysis are discussed. The advantages of the utilization the LHS method to analyze the safety and reliability of the structures is presented.

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Application of Joint Boring Technique in Solving RCL Wall Thickness Problem

Volume 1: Operations and Maintenance, Engineering, Modifications, Life Extension, Life Cycle and Balance of Plant; I&C, Digital Controls, and Influence of Human Factors ◽

10.1115/icone25-66026 ◽

2017 ◽

Author(s):

Huadong Zhu

Keyword(s):

Power Plant ◽

Nuclear Power Plant ◽

Wall Thickness ◽

Nuclear Power ◽

Coolant Pump ◽

Reactor Coolant ◽

Design Requirements ◽

Nuclear Power Project ◽

Power Project ◽

Service Inspection

Nuclear Power Project RCL (reactor coolant loop) is one of the most critical nuclear safety class 1 equipment in PWR nuclear power plant. Filled with borated water, the RCL is a closed loop and serves as pressure boundary incorporating the reactor pressure vessel, steam generator and reactor coolant pump. Since in-service inspection is required for welds of the RCL, the two sides of the welds shall be bored to meet UT (Ultrasonic Testing) inspection requirements. The design standard states that “if the weld is subject to service inspection, the length of the counterbore shall be 2Tmin (Tmin = minimum of wall thickness) for pipe and Tmin for components and fittings. Therefore, the minimal wall thickness of the boring area inside the RCL shall also meet design requirements. Examination of the RCLs delivered to the nuclear power project sites showed that the wall thickness of some parts of the RCL exceed tolerance in varying degrees (the wall thickness is too thin). The RCL borings need to be analyzed to mitigate the negative impact of insufficient wall thickness, maintain RCL wall thickness to the largest extent and meet design requirements. Under the condition of the jobsite data are idealized, this study analyzes the boring plans for the cold leg of loop B at the reactor vessel side for this nuclear power plant Unit 1 NI (Nuclear Island) and discusses the three methods of boring, namely, general boring, taper boring and eccentric boring. It finds that a combination of taper boring and eccentric boring is the optimal plan. This joint boring technique can help achieve the minimal boring wall thickness, reduce the grinding quantity and maintain the required wall thickness, thus resolving the out-of-tolerance issue. In addition, it meets the design requirements, the wall thickness and in-service inspection requirements. Supervision agency approved the application of the joint boring technique to the RCL for the projects. The RCL installation has proved to be a success.

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Seismic Performance of CAP1400 Nuclear Power Station considering Foundation Uplift

Shock and Vibration ◽

10.1155/2018/8761209 ◽

2018 ◽

Vol 2018 ◽

pp. 1-16 ◽

Cited By ~ 1

Author(s):

Ling-Yun Peng ◽

Ying-Jie Kang ◽

Zhen-Yun Tang ◽

Hua-Ting Chen

Keyword(s):

Power Plant ◽

Nuclear Power Plant ◽

Seismic Performance ◽

Nuclear Power ◽

Shaking Table Test ◽

Shaking Table ◽

Test Model ◽

Foundation Slab ◽

Adjacent Structures ◽

Design Requirements

Under earthquake action, the reinforced concrete structure at the edge of the CAP1400 nuclear power plant foundation slab will be uplifted. In order to determine the seismic performance of this structure, a 1 : 12 scale shaking table test model was fabricated using gypsum as simulated concrete in order to meet scaled design requirements. By testing this model, the seismic response of the structure with consideration of the foundation uplift was obtained. Numerical analyses of the test model and the prototype structure were conducted to gain a better understanding of the structural seismic performance. When subjected to earthquakes, the foundation slab of the nuclear power plant experiences a slight degree of uplift but remains in the elastic stage due to the weight of the structure above, which provides an antioverturning moment. The numerical simulation is in general agreement with the test results, suggesting numerical simulations could be accurately employed in place of physical tests. The superstructure displacement response was found not to affect the safety of adjacent structures, and the seismic performance of the structure was shown to meet the relevant design requirements, demonstrating that this approach to modelling can serve as a design basis for the CAP1400 nuclear power demonstration project.

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