Preliminary Research on the Elimination of OBE in the Seismic Design of NPP

2013 ◽  
Author(s):  
Qiang Li ◽  
Jian Zhang
Keyword(s):  
Seismic Design ◽  
Nuclear Power ◽  
Power Plants ◽  
Nuclear Power Plants ◽  
User Requirements ◽  
Regulatory Requirements ◽  
Standard Design ◽  
Explicit Analysis ◽  
Design Analyses ◽  
Requirements Documents

Two levels of seismic, i.e. OBE and SSE, are conventionally considered in the seismic design of nuclear power plants. OBE is formerly set to equal to one half of SSE. In Advanced Light Water Reacter User Requirements Documents (ALWR-URD), US EPRI recommented to decrease OBE to one third of SSE. In the standard design of third generation of nuclear power plants, such as AP1000 of Westinghouse and EPR of AREVA, OBE was eliminated and substituted by lower level earthquake. In AP1000 standard design, OBE was decreased to one third of SSE and explicit analysis on OBE in the seimic design analyses is not required. Literatures and reports related to the regulatory requirements of seismic design are reviewed to study the reasons and means to be taken to address the issue of elimination of OBE from the design analyses of NPP. It will provide guidelines on the issue of elimination of OBE from seimic analysis of NPP design in China.

Overview of Seismic Issues in Design Certification and Combined License Application Reviews

2009 ◽  
Author(s):  
Jim Xu ◽  
Sujit Samaddar
Keyword(s):  
Seismic Design ◽  
Nuclear Power ◽  
Power Plants ◽  
Nuclear Power Plants ◽  
Response Spectra ◽  
Nuclear Regulatory Commission ◽  
Lessons Learned ◽  
Site Specific ◽  
License Application ◽  
Standard Design

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.

A Critical Comparison of Seismic Qualification Requirements for Safety Equipment in Various Codes and Standards

2003 ◽  
Author(s):  
F. G. Abatt ◽  
Quazi Hossain ◽  
Milon Meyer
Keyword(s):  
Seismic Performance ◽  
Seismic Design ◽  
Nuclear Power ◽  
Power Plants ◽  
Nuclear Power Plants ◽  
Lower Class ◽  
Department Of Energy ◽  
Building Structures ◽  
Performance Category ◽  
Code Provisions

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.

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