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Title: Generic seismic ruggedness of power plant equipment

Abstract

This report updates the results of a program with the overall objective of demonstrating the generic seismic adequacy of as much nuclear power plant equipment as possible by means of collecting and evaluating existing seismic qualification test data. These data are then used to construct ruggedness'' spectra below which equipment in operating plants designed to earlier earthquake criteria would be generically adequate. This document is an EPRI Tier 1 Report. The report gives the methodology for the collection and evaluation of data which are used to construct a Generic Equipment Ruggedness Spectrum (GERs) for each equipment class considered. The GERS for each equipment class are included in an EPRI Tier 2 Report with the same title. Associated with each GERS are inclusion rules, cautions, and checklists for field screening of in-place equipment for GERS applicability. A GERS provides a measure of equipment seismic resistance based on available test data. As such, a GERS may also be used to judge the seismic adequacy of similar new or replacement equipment or to estimate the seismic margin of equipment re-evaluated with respect to earthquake levels greater than considered to date, resulting in fifteen finalized GERS. GERS for relays (included in the original versionmore » of this report) are now covered in a separate report (NP-7147). In addition to the presentation of GERS, the Tier 2 report addresses the applicability of GERS to equipment of older vintage, methods for estimating amplification factors for evaluating devices installed in cabinets and enclosures, and how seismic test data from related studies relate to the GERS approach. 28 refs., 5 figs., 4 tabs.« less

Authors:
 [1]
  1. (Anco Engineers, Inc., Culver City, CA (United States))
Publication Date:
Research Org.:
Electric Power Research Inst., Palo Alto, CA (United States); Anco Engineers, Inc., Culver City, CA (United States)
Sponsoring Org.:
EPRI; Electric Power Research Inst., Palo Alto, CA (United States)
OSTI Identifier:
5288388
Report Number(s):
EPRI-NP-5223-M-Rev.1
Resource Type:
Technical Report
Country of Publication:
United States
Language:
English
Subject:
22 GENERAL STUDIES OF NUCLEAR REACTORS; 99 GENERAL AND MISCELLANEOUS//MATHEMATICS, COMPUTING, AND INFORMATION SCIENCE; ELECTRICAL EQUIPMENT; SEISMIC EFFECTS; MECHANICAL STRUCTURES; NUCLEAR POWER PLANTS; REACTOR COMPONENTS; ANCHORS; DAMPING; DATA ACQUISITION; DATA BASE MANAGEMENT; EARTHQUAKES; REACTOR SAFETY; VULNERABILITY; EQUIPMENT; MANAGEMENT; NUCLEAR FACILITIES; POWER PLANTS; SAFETY; SEISMIC EVENTS; THERMAL POWER PLANTS 220900* -- Nuclear Reactor Technology-- Reactor Safety; 220200 -- Nuclear Reactor Technology-- Components & Accessories; 990300 -- Information Handling

Citation Formats

Merz, K.L.. Generic seismic ruggedness of power plant equipment. United States: N. p., 1991. Web.
Merz, K.L.. Generic seismic ruggedness of power plant equipment. United States.
Merz, K.L.. 1991. "Generic seismic ruggedness of power plant equipment". United States. doi:.
@article{osti_5288388,
title = {Generic seismic ruggedness of power plant equipment},
author = {Merz, K.L.},
abstractNote = {This report updates the results of a program with the overall objective of demonstrating the generic seismic adequacy of as much nuclear power plant equipment as possible by means of collecting and evaluating existing seismic qualification test data. These data are then used to construct ruggedness'' spectra below which equipment in operating plants designed to earlier earthquake criteria would be generically adequate. This document is an EPRI Tier 1 Report. The report gives the methodology for the collection and evaluation of data which are used to construct a Generic Equipment Ruggedness Spectrum (GERs) for each equipment class considered. The GERS for each equipment class are included in an EPRI Tier 2 Report with the same title. Associated with each GERS are inclusion rules, cautions, and checklists for field screening of in-place equipment for GERS applicability. A GERS provides a measure of equipment seismic resistance based on available test data. As such, a GERS may also be used to judge the seismic adequacy of similar new or replacement equipment or to estimate the seismic margin of equipment re-evaluated with respect to earthquake levels greater than considered to date, resulting in fifteen finalized GERS. GERS for relays (included in the original version of this report) are now covered in a separate report (NP-7147). In addition to the presentation of GERS, the Tier 2 report addresses the applicability of GERS to equipment of older vintage, methods for estimating amplification factors for evaluating devices installed in cabinets and enclosures, and how seismic test data from related studies relate to the GERS approach. 28 refs., 5 figs., 4 tabs.},
doi = {},
journal = {},
number = ,
volume = ,
place = {United States},
year = 1991,
month = 8
}

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  • This report presents the results of a program with the overall objective of demonstrating the generic seismic adequacy of as much nuclear power plant equipment as possible by means of collecting and evaluating existing seismic qualification test data. These data are then used to construct ''ruggedness'' spectra below which equipment in operating plants designed to earlier earthquake criteria would be generically qualified. The report gives the methodology for the collection and evaluation of data which are used to construct a Generic Equipment Ruggedness Spectrum (GERS) for each equipment class considered. Associated with each GERS are inclusion rules, cautions, and checklistsmore » for field screening of in-place equipment for GERS applicability. The collected data is available as a computerized Electric Power Research Institute data base accessible to utilities. A GERS provides a measure of equipment seismic resistance based on available test data. As such, a GERS may also be used to judge the seismic adequacy of new or replacement equipment or to estimate the seismic margin of equipment reevaluated with respect to earthquake levels greater than considered in the original design. Twenty-five equipment classes have been considered to date, resulting in nineteen finalized GERS.« less
  • In December 1980, the US Nuclear Regulatory Commission (NRC) designated Seismic Qualification of Equipment in Operating Plants'' as an Unresolved Safety Issue (USI), A-46. The objective of USI A-46 is to develop alternative seismic qualification methods and acceptance criteria that can be used to assess the capability of mechanical and electrical equipment in operating nuclear power plants to perform the intended safety functions. A group of affected utilities formed the Seismic Qualification Utility Group (SQUG) to work with the NRC in developing a program methodology to enable resolution of the A-46 issue. To assist in developing a program methodology, SQUGmore » and the NRC jointly selected and supported a five-member Senior Seismic Review and Advisory Panel (SSRAP) in June 1983 to make an independent assessment of whether certain classes of equipment in operating nuclear power plants in the United States have demonstrated sufficient ruggedness in past earthquakes so as to render an explicit seismic qualification unnecessary. SSRAP operated as an independent review body with all of its findings submitted concurrently to both SQUG and the NRC. During their period of involvement, SSRAP issued several draft reports on their conclusions. This document contains the final versions of these reports; namely, Use of Seismic Experience and Test Data to Show Ruggedness of Equipment in Nuclear Power Plants,'' dated February 1991 and Review Procedure to Assess Seismic Ruggedness of Cantilever Bracket Cable Tray Supports,'' dated March 1, 1991.« less
  • In December 1980, the US Nuclear Regulatory Commission (NRC) designated ``Seismic Qualification of Equipment in Operating Plants`` as an Unresolved Safety Issue (USI), A-46. The objective of USI A-46 is to develop alternative seismic qualification methods and acceptance criteria that can be used to assess the capability of mechanical and electrical equipment in operating nuclear power plants to perform the intended safety functions. A group of affected utilities formed the Seismic Qualification Utility Group (SQUG) to work with the NRC in developing a program methodology to enable resolution of the A-46 issue. To assist in developing a program methodology, SQUGmore » and the NRC jointly selected and supported a five-member Senior Seismic Review and Advisory Panel (SSRAP) in June 1983 to make an independent assessment of whether certain classes of equipment in operating nuclear power plants in the United States have demonstrated sufficient ruggedness in past earthquakes so as to render an explicit seismic qualification unnecessary. SSRAP operated as an independent review body with all of its findings submitted concurrently to both SQUG and the NRC. During their period of involvement, SSRAP issued several draft reports on their conclusions. This document contains the final versions of these reports; namely, ``Use of Seismic Experience and Test Data to Show Ruggedness of Equipment in Nuclear Power Plants,`` dated February 1991 and ``Review Procedure to Assess Seismic Ruggedness of Cantilever Bracket Cable Tray Supports,`` dated March 1, 1991.« less
  • Generic floor response spectra were developed for use in the qualification of electrical and mechanical equipment in operating nuclear power plants. The characteristics of 1000 floor response spectra were studied to determine the generic spectra. The procedure developed uses as much or as little information that currently exists at the plant relating to the question of equipment qualification. The general approach was to study the effects on the dynamic characteristics of each of the elements in the chain of events that goes between the loads and the responses. This includes the loads, the soils and the structures. A free-field earthquakemore » response spectra was used to generate horizontal earthquake time histories. The excitation was applied through the soil and into the various structures to produce responses in equipment. An entire range of soil conditions was used with each structure. Actual PWR and BWR - Mark I structural models were used. For each model, the stiffness properties were varied, with the same mass, so as to extend the fundamental base structure natural frequency from 2 cps to 36 cps. The natural frequencies of the structures were varied to obtain maximum response conditions. The actual properties were first used to locate the natural frequencies. The stiffness properties were than varied, with the same mass, to extend the range of the fundamental base structure natural frequency. The intention was to have the coupled structural material frequencies in the vicinity of the peak amplitude frequency content of the excitation spectrum. Particular attention was therefore given to the frequency band between 2 Hz and 4 Hz. A horizontal generic floor response spectra is proposed for the top level of a generic structure. Reduction factors are applied to the peak acceleration for equipment at lower levels.« less