Regulatory Guide 1.100

Seismic Qualification of Electric Equipment for Nuclear Power Plants.

ML12305A261
Person / Time
Issue date:	08/31/1977
From:	NRC/OSD, Office of Nuclear Regulatory Research
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References
RG-1.100, Rev. 1
Download: ML12305A261 (3)

Revision I

U.S. NUCLEAR REGULATORY COMMISSION August 1977 REGULATORY GUIDE

OFFICE OF STANDARDS DEVELOPMENT

REGULATORY GUIDE 1.100

SEISMIC QUALIFICATION OF ELECTRIC

EQUIPMENT FOR NUCLEAR POWER PLANTS

A. INTRODUCTION

The provisions of the standard include principles, procedures, and methods of seismic qualification Criterion III, "Design Control," of Appendix B, which, when satisfied, will confirm the adequacy of

"Quality Assurance Criteria for Nuclear Power the equipment design for the performance of Class I E

Plants and Fuel Reprocessing Plants," to 10 CFR functions during and after the time the equipment is Part 50, "Licensing of Production and Utilization subjected to the forces resulting from one safe shut- Facilities," requires, among other things, that design down earthquake (SSE) preceded by a number of control measures provide for verifying the adequacy operating basis earthquakes (OBE0s). The standard of design such as by the performance of a suitable contains requirements indicated by the verbs "shall"

testing program. Where a test program is used to and "must" and recommendations indicated by verify the adequacy of a specific design feature, it is "should."

required to include suitable qualification testing of a prototype unit under the most adverse design condi- The standard, which is an ancillary standard of tions. This regulatory guide describes a method ac- IEEE Std 323-1974, "IEEE Standard for Qualifying ceptable to the NRC staff for complying with the Class I E Equipment for Nuclear Power Generating Commission's regulations with respect to verifying Stations," (endorsed, with exceptions, by Regulatory the adequacy of the seismic design of electric equip- Guide 1.89, "Qualification of Class IE Equipment ment for all types of nuclear power plants. The Ad- for Nuclear Power Plants"), supplements part of the visory Committee on Reactor Safeguards has been test methods required and references the margins consulted concerning this guide and has concurred in given in IEEE Std 323-1974.

the regulatory position.

B. DISCUSSION

Conformance with the requirements and recom- IEEE Std 344-1975f(revision of IEEE Std 344- mendations specified by IEEE Std 344-1975' for con-

1971), "IEEE Recommended Practices for Seismic ducting seismic qualification of Class 1E equipment, Qualification of Class 1E Equipment for Nuclear when such qualification is performed in conjunction Power Generating Stations," dated January 31, 1975, with Regulatory Guide 1.89, provides an adequate was prepared by Working Group 2.5 (Seismic Qualification) of Subcommittee 2 (Equipment basis for complying with design verification require- ments of Criterion III of Appendix B to 10 CFR Part Qualification) of the Institute of Electrical and

50 with respect to verifying the seismic adequacy of Electronics Engineers (IEEE) Nuclear Power electric equipment, subject to the following:

Engineering Committee and was subsequently ap- proved by the IEEE Standards Board on December 1. As indicated in Section 5.3, "Static Coefficient

20, 1974. Analysis," a static coefficient of 1.5 is used for equip-

• Lines indicate substantive changes from previous issue. ment analysis to take into account the effects of both

'Copies may be obtained from the Institute of Electrical and multi frequency excitation and multimode response.

Electronics Engineers, United Engineering Center, 345 East 47th The use of 1.5 as the static coefficient is acceptable Street, New York, N.Y. 10017. for verifying structural integrity of frame-type struc- USNRC REGULATORY GUIDES Comments should be sent to the Secretary of the Commission, US. Nuclear Regu- latory Commission, Washington, D.C. 20555, Attention: Docketing and Service Regulatory Guides are issued to describe and make available to the Public methods Branch.

acceptable to the NRC staff of implementing specific parts of the Commission's regulations, to delineate techniques used by the staff in evaluating specific problems The guides are issued in the following ten broad divisions:

or postulated accidents, or to provide guidance to applicants. Regulatory Guides are not substitutes for regulations, and compliance with them is not required. 1. Power Reactors 6. Products Methods and solutions different from those set Out in the guides wil be accept- 2. Research and Test Reactors 7. Transportation able if they provide a basis for the findings requisite to the issuance or continuance 3. Fuels and Materials Facilities 8. Occupational Health of a permit or license by the Commission. 4.

5. Environmental Materials and Protection and Plant Siting

9. Antitrust Review

10. General Comments and suggestions for improvements in these guides are encouraged at all Requests for single copies of issued guides (which may be reproduced) or for place- times, and guides will be revised, as appropriate, to accommodate comments and ment on an automatic distribution list for single copies of future guides in specific to reflect new information or experience. This guide was revised as a result of divisions should be made in writing to the US. Nuclear Regulatory Commission, substantive comments received from the public and additional staff review. Washington, D.C, 20555, Attention: Director, Division of Document Control.

tures, such as members physically similar to beams As stated in regulatory position 2, one of the re- and columns, that can be represented by a simple quirements to ensure equipment operability is to ex- model. For equipment having configurations other cite all modes of the equipment adequately and than a frame-type structure, justification should be simultaneously to the required levels. One of the provided for use of a static coefficient. criteria used to verify the adequacy of the test input is to have the TRS enveloping the RRS as specified in

2. Section 6.6.2.1, "Derivation of Test Input Section 6.6.1 of the standard. The sine sweep test may Motion," (concerning single-frequency test input not be suitable for equipment qualification for the motion) states that, for equipment with more than following reasons:

one predominant frequency, the shake table motion should produce a test response spectrum (TRS) ac- a. For a fast sweep, even though the equipment celeration at the test frequencies equal to 1.5 times may sense nearly simultaneous multimode effects, the the acceleration given by the specified required duration for each mode to be excited may be too brief response spectrum (RRS) or less if justified. The sec- to induce adequate resonance as compared to the ac- tion also states that the TRS need not envelop the tual excitations.

RRS provided the factor of 1.5 is used.

b. For a slow sweep, the effects are nearly excita- The use of a factor of 1.5 and the concept that tion of one mode at a time. Even with the TRS being the TRS need not envelop the RRS as a consequence broad band and enveloping the RRS, the true sense of using 1.5 should not, in the absence of justifica- of simultaneous multimode response is not provided.

tion, be considered acceptable. For example, in the event that the RRS is broad band, the use of single- Sections 6.6.2 and 6.6.2.1 do not provide specific frequency test input with a 1.5 magnification factor guidelines concerning either the sweep rate or a may not be adequate to excite all modes to the re- justifiable methodology to define the TRS for a quired levels. For ensuring operability of an equip- sweep input motion.

ment under seismic event, the test input motion 4. The requirements given in Section 8, "Documen- should closely simulate the characteristics of excita- tion. An equipment malfunction may not be tation," should be supplemented by the following:

governed by the level of stress but is frequently caused by the vibratory behavior of the response. As 8.6 Malfunction Data stated in Section 6.6.1 of the standard, one of the general requirements for a justifiable seismic test in- If a malfunction as defined in Section 2, put is that the wave forms should produce a TRS that "Definitions," is experienced during any test, the ef- closely envelops the applicable portion of the RRS. fect of that malfunction should be determined and This requirement is intended to ensure that all modes documented in the test report.

of an equipment are adequately and simultaneously excited to the required level

s. Since the TRS

produced by the single-frequency test input is narrow

D. IMPLEMENTATION

band and the RRS may be broad band, the use of single-frequency test input with a 1.5 magnification The purpose of this section is to provide informa- factor may not always be adequate to excite all modes tion to applicants regarding the NRC staff's plans for of the equipment to the required levels. Thus it is using this regulatory guide.

necessary that the TRS closely envelop the applicable portion of the RRS to verify the adequacy of test in- This guide reflects current NRC staff practice.

put motion. Therefore, except in those cases in which the appli- cant proposes an acceptable alternative method for

3. In the absence of justification, those portions of complying with the specified portions of the Commis- Section 6.6.2.5, "Sine Sweep Test," which indicate sion's regulations, the method described herein is be- that, for qualifying equipment using the sine sweep ing and will continue to be used in the evaluation of test input, the TRS must envelop the RRS according submittals for construction permit applications until to the criteria described in Sections 6.6.2 and 6.6.2.1 this guide is revised as a result of suggestions from the should not be considered acceptable. public or additional staff review.

1.100-2

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NUCLEAR REGULATORY COMMISSION

WASHINGTON, D. C. 20555 POSTAGE AND FEES PAID

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