Seismic Design for Nuclear Power Plants

1971 ◽  
Vol 43 (3) ◽  
pp. 355-355
Author(s):  
Hood Worthington
Author(s):  
Jim Xu ◽  
Sujit Samaddar

The U.S. Nuclear Regulatory Commission (NRC) established a new process for licensing nuclear power plants under Title 10 of the Code of Federal Regulations (10 CFR) Part 52, “Licenses, Certifications, and Approvals for Nuclear Power Plants,” which provides requirements for early site permits (ESPs), standard design certifications (DCs), and combined license (COL) applications. In this process, an application for a COL may incorporate by reference a DC, an ESP, both, or neither. This approach allows for early resolution of safety and environmental issues. The COL review will not reconsider the safety issues resolved by the DC and ESP processes. However, a COL application that incorporates a DC by reference needs to demonstrate that pertinent site-specific parameters are confined within the safety envelopes established by the DC. This paper provides an overview of site parameters related to seismic designs and associated seismic issues encountered in DC and COL application reviews using the 10 CFR Part 52 process. Since DCs treat the seismic design and analysis of nuclear power plant (NPP) structures, systems, and components (SSC) as bounding to future potential sites, the design ground motions and associated site parameters are often conservatively specified, representing envelopes of site-specific seismic hazards and parameters. For a COL applicant to incorporate a DC by reference, it needs to demonstrate that the site-specific hazard in terms of ground motion response spectra (GMRS) is enveloped by the certified design response spectra of the DC. It also needs to demonstrate that the site-specific seismic parameters, such as foundation-bearing capacities, soil profiles, and the like, are confined within the site parameter envelopes established by the DC. For the noncertified portion of the plant SSCs, the COL applicant should perform the seismic design and analysis with respect to the site-specific GMRS and associated site parameters. This paper discusses the seismic issues encountered in the safety reviews of DC and COL applications. Practical issues dealing with comparing site-specific features to the standard designs and lessons learned are also discussed.


2003 ◽  
Author(s):  
F. G. Abatt ◽  
Quazi Hossain ◽  
Milon Meyer

Evaluation of life safety risks to facility occupants, public, and the environment that may result from earthquake events involves both building structures and equipment supported from these structures. But, it is the seismic design of building structures that typically receive the bulk of the attention from the code committees of the national professional organizations and the regulatory authorities. For safety related equipment in nuclear facilities (e.g., Seismic Category I equipment in nuclear power plants and Seismic Performance Category 3 and 4 equipment in the Department of Energy facilities), the seismic design and analysis guidelines and acceptance criteria are well established. But, for Nonseismic Category equipment in nuclear power plants and Seismic Performance Category 1 and 2 equipment in Department of Energy facilities, these have not yet been developed to the same level of completeness and rigor. The code provisions and guidelines available today for these lower class/categories of equipment are briefly, but critically discussed here, along with a comparison of the results of the application of these code provisions.


2020 ◽  
Vol 10 (10) ◽  
pp. 3624
Author(s):  
Tamás János Katona

The hazard of permanent ground displacements/deformations can challenge the safety of the nuclear power plants. Increasing knowledge of the hazard and development of methods for structure–fault–displacement interaction motivates the designing of nuclear power plants for permanent ground displacement instead of abandoning the sites that could be affected by this kind of hazard. For the design basis, permanent ground displacement should be defined at the hazard level that complies with the probabilistic criteria for accounting for the natural hazards in the design that also ensure compliance with probabilistic safety criteria. In this paper, a procedure is proposed for the definition of the design basis permanent ground displacement that is based on the deaggregation of seismic design basis hazard. The definition of the displacement for the margin evaluation is also proposed. The feasibility of safe design is also demonstrated for the proposed definition of design basis hazard via qualitative judgement on the sensitivity of the structures, systems and components ensuring the fundamental safety functions with respect to the permanent ground displacement that is supported by existing case studies.


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