Regulatory Guide 1.29

Seismic Design Classification

ML13350A385
Person / Time
Issue date:	02/28/1976
From:	NRC/OSD
To:
References
RG-1.029, Rev. 2
Download: ML13350A385 (3)

U.S. NUCLEAR REGULATORY COMMISSION Revision 2 February 1976 REGULATORY GUIDE

OFFICE OF STANDARDS DEVELOPMENT

REGULATORY GUIDE 129 SEISMIC DESIGN CLASSIFICATION

A. INTRODUCTION

nuclear power plants that should designed to with.

stand the effects of the SSE. J

A hL

General Design Criterion 2, "Design Bases for Protec- tion Against Natural Phenomena," of Appendix A, B. DISC*

"General Design Criteria for Nuclear Power Plants," to

10 CFR Part 50, "Licensing of Production and Utiliza- After reviewing a splqol plications for con- struction permits o ngj

'enses for boiling and tion Facilities," requires that nuclear power plant pressurized water c r plants, the NRC staff structures, systems, and components important to safety "gn classification system for has developed a be designed to withstand the effects of earthquakes identifying p ures that should be designed without loss of capability to perform their safety to withstan fec5 of the SSE. Those structumes, functions.

S ents that should be designed to if the 4ZqIF n-t-vc ho rp, n vt.ei .

Appendix B, "Quality Assurance Criteria for Nuclear .-.. 1.

Power Plants and Fuel Reprocessing Plants," to 10 CFR as~icLategory Part 50 establishes quality assurance requirements for

C. REGULATORY POSITION

the design, construction, and operation of nuclear power plant structures, systems, and components that prevent e following structures, systems, and compo- or mitigate the consequences of postulated acc' n ts of a nuclear power plant, including their founda- that coubldc.aTe unuertisnto theqremntsof and of tions and supports, are designated as Seismic Category apply to all activeit eing the safeqtu.imd and should be designed to withstand the effects of theI

applyofthose all rctivites,affeti ng the sfen SSE and remain functional. The pertinent quality tions of those structures, systems, and conw~nents, assurance requirements of Appendix B to 10 CFR Part Appendix A, "Seismic and Geologic iSteria 50 should be applied to all activities affecting the for Nuclear Power Plants," to 10 CFR Part 100, safety-related functions of these structures, systems, and

"Reactor Site Criteria," requ that all nuclear power components.

plants be designed so - the Safe Shutdown Earthquake (SSE) occurs, es, systems, and a. The reactor coolant pressure boundary.

components import 0 remain functional.

These plant featurh essary to ensure (1) b. The reactor core and reactor vessel internals.

the integrity of th at oant pressure boundary,

(2) the capab t * the reactor and maintain c. Systems' or portions of systems that are it in a safe td'n ion, or (3) the capability to required for (1) emergency core cooling, (2) postacci- prevent or a. the consequences of accidents that dent containment heat removal, or (3) postaccident could result in tial offsite exposures comparable to the guideline exposures of 10 CFR Part 100. The- system boundary includes those portions of the system ter.q di~ to

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connected piping up to and including the first valve (including a This guide describes an acceptable method of identi. safety or relief valve) that is either nornally closed or capable fying and classifying those features of light.water.cooled of automatic closure when the safety function is required.

USNRC REGULATORY GUIDES commen*s, should be sent to the secreary of the Commission. U.S aetlest Rgulato*r, Gweiel are fted to desincribe end make evaible to th. ib~l. Regulatory Commission. Washongto,, 0 C 206. Attaenton Ooceotmg and methods acceptable 1o the NRC %lellof Implementing specific pont of the Sartce Sacton Commisson' regulations. to delineate techniques uled by the %I&" i ovoU The guides ar Issued , the following tor broad divsons at1" sglif¢c peOblerns or poouleated accidents. or to proetsa jog.,dnce to sopl c*t, fagultaorey Guides are not substitutes fat reiatraol.fs, and conpliance I Power Reactors 6 Prodvcte woth themrt not toqruied Methods and sOlutions ditferent from those tat Out on 2 Research and Tolt Reactors I 1tanspOrletDon the guidaes wil be acceptable J9they provide a bel fot the finding$ realusilt to 2 Fuels and Materals Facilities a Occupatiorel HMeath the *.suance or conulruunce of a Permi or ocent. by the Commission 4 fnroonmenttl aendSli.ng I AnttIuel Review Comment. and tuggesttuntt ofa,rmproomeflls .n that* guides are encouraged S Mterial& and Plant Protection 10 General at elf troeS and g;dmi wI be , a.led at sporopa g0oaccom* odlat caom manla end to *ettIctnew ,injotornron or oopefence Ioweve. Comment, on Copoge of pubklshed guides may be obltme/d by wirltn request indicating Ith Ihis guide. 0t receiead Winhr.t About two months &latet ISluafnce. wilt be Par divisions desired to the U S Nuclear 0aegvletory Comigneitong. Washmtlon, 0 C

lcumI' usefutl in evaluating the need fat arn*calI revlsion 2065. Altaenton Director. Office a9 Standl Oletevelopment

containment atmosphere weanup (e.g., hydrogen re- n. The control room, including its associated vital moval system). equipment, cooling systems for vital equipment, and life support systems, and any structures or equipment inside d. Systems' or portions of systems that are or outside of the control room whose failure could result requized for (1) reactor shutdown, (2) residual heat in incapacitating Injury to the occupants of the control

2 removal, or (3) cooling the spent fuel storage pool. room.

e. Those portions of the steam systems of boiling water reactors extending from the outermost contain- o. Primary and secondary reactor containment.

ment isolation valve up to but not including the turbine stop valve, and connected piping of 2-1/2 inches or p. Systems,' other than radioactive waste manage- larger nominal pipe size up to and including nhe first ment systems,3 not covered by itemns l.a through 1.o I $

valve that is either normally closed or capable of above that contain or may contain radioactive material automatic closure during all modes of normal reactor and whose postulated failure would result in consrva- operation. The turbine stop valve should be designed to tively calculated potential offsite doses (using mete- withstand the SSE and maintain its integrity. orology as prescribed by Regulatory Guide 1.3, "As- sumptions Used for Evaluating the Potential Radio- f. Those portions of the steam and feedwater logical Consequences of a Loss of Coolant Accident for systems of pressurized water reactors extending from Boiling Water Reactors," and Regulatory Guide 1.4, and Including the secondary side of steam generators up "Assumptions Used for Evaluating the Potential Radio- to and Including the outermost containment isolation logical Consequences of a Loss of Coolant Accident for vulve, and connected piping of 2-1/2 inches or larger Pressurized Water Reactors") that are more than 0.5 rem nominal pipe size up to and including the first valve to the whole, body or its equivalent to any part of the (including a safety or relief valve) that is either normally body.

dosed or capable of automatic closure during all modes of normal reactor operation.

q. The Class IE electric systems, including the g. Cooling water, component cooling, and auxil- auxiliary systems for the onsite electric power supplies, iaty feedwater systems' or portions of these systems, that provide the emergency electric power needed for including the intake structures, that are required for (1) functioning of plant features included in items l.a emzerncy core cooling, (2) postaccident containment through Lp above.

heat removal, (3) postaccident containment atmosphere cleanup, (4) residual heat removal from the reactor, or 2. Those portions of structures, systems, or compo-

(5) cooling the spent fuel storage pool.

nents whose continued function is not required but whose failure could reduce the functioning of any plnat h. Cooling water and seal water systems' or feature included in items La through l.q above to an portions of these systems that are required for function- unacceptable safety level should be designed and con- ing of reactor coolant system components important to structed so that the SSE would not cause such failure.

safety, such as reactor coolant pumps.

I. Systems' or portions of systems that are re- 3. Seismic Category I design requuements should quired to supply fuel for emergency equipment. extend to the first seismic restraint beyond the defined boundaries. Those portions of structures, systems, or j. All electric and mechanical devices and circuitry components that form interfaces between Seismic Cate- between the process and the input terminals of the gory I and non-Seismic Category I features should be actuator systems involved in gpnerating signals that designed to Seismic Category I requirements.

initiate protective acUon.

4. The pertinent quality assurance requirements of k. Systems' or portions of systems that are Appendix B to 10 CFR Part 50 should be applied to all required for (I) monitoring of systems important to activities affecting the safety-related functions of those safety and (2) actuation of systems important to safety.

portions of structures, systems, and components covered under Regulatory Positions 2 and 3 above.

1. The spent fuel storage pool structure, including the fuel racks.

• Lie indicate substantive changes from previous issue.

m. The reactivity control systems, e.g., control 'Wherever practical, structures and equipment whose failure rods, control rod drives, and boron injection system. could possibly cause such injuries should be relocated or separated to the extent required to eliminate this possibility.

'Specific guidance on seismic requirements for radioactive waste

'See footnote 1, p. 1.29-1. management systems is under developmen

t. I

1.29-2

"I

D. IMPLEMENTATION

proposes an acceptable alternative method for comply- The purpose of this section is to provide information ing with Tpecifled portions of the Commission's regula.

to applicants regarding the NRC staff's plans for using tions, the method described herein is being and will this regulatory guide. continue to be used in the evaluation of submittals for operating license or construction permit applications I This guide reflects current NRC staff practice. There.

fore, except in those 'cases In 'which the applicant until this guide is revised as a result of suggestions from the public or additional staff review.

1.29.3