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{{#Wiki_filter:U.S. NUCLEAR REGULATORY COMMISSIONREGULATORY GUIDEOFFICE OF STANDARDS DEVELOPMENTREGULATORY GUIDE 1.20COMPREHENSIVE VIBRATION ASSESSMENT PROGRAMFOR REACTOR INTERNALS DURINGPREOPERATIONAL AND INITIAL STARTUP TESTINGRevision 1June | {{#Wiki_filter:U.S. NUCLEAR REGULATORY COMMISSIONREGULATORY GUIDEOFFICE OF STANDARDS DEVELOPMENTREGULATORY GUIDE 1.20COMPREHENSIVE VIBRATION ASSESSMENT PROGRAMFOR REACTOR INTERNALS DURINGPREOPERATIONAL AND INITIAL STARTUP TESTINGRevision 1June 1975 | ||
==A. INTRODUCTION== | |||
Criterion 1, "Quality Standards and Records," ofAppendix A, "General Design Criteria for Nuclear'PowerPlants," to 10 CFR Part 50, "Licensing of Productionand Utilization Facilities," requires that structures,systems, and components important to safety bedesigned, fabricated, erected, and tested to qualitystandards commensurate with the importance of thesafety functions to be performed. Section 50.34, "Con-tents of Applications; Technical Information," of 10CFR Part 50 requires the applicant to determine and tospecify the margin of safety associated with normaloperation and anticipated operating transients.This guide presents a method acceptable to the NRCstaff for implementing the above requirements withrespect to the internals of light-water-cooled reactors'during preoperational and initial startup testing.2 Inser-vice inspections and inservice monitoring programs toverify that the reactor internal components have notbeen subjected to structural degradation as a result ofvibration during normal reactor operation are notcovered by this guide.'Reactor internals, as used in this regulatory guide, comprisecore support structures and adjoining internal structures. Coresupport and internal structures are defined in Article NG-I 120of Section 111 (Nuclear Power Plant Components) of the ASMEBoiler and Pressure Vessel Code.kConsistent with Regulatory Guide 1.68, "Preoperational andInitial Startup Test Programs for Water-Cooled PowerReactors," preoperational testing as used in this guide consistsof those tests conducted prior to fuel loading, and intial startuptesting refers to those tests performed after fuel loading. | |||
==B. DISCUSSION== | |||
Reactor internals important to safety are designed toaccommodate steady-state and transient vibratory loadsfor the service life of the reactor. This guide presents acomprehensive vibration assessment program for use inverifying the structural integrity of the reactor internalsfor flow-induced vibrations prior to commercial opera-tion. The overall program includes individual analytical,measurement, and inspection programs. The term "com-prehensive" appears in the title of the overall program toemphasize that the individual programs should be usedcooperatively to verify structural integrity and to estab-lish the margin of safety. For example, the analyticalprogram not only should be used to provide theoreticalverification of structural integrity but also should be thebasis for the choice of components and areas to bemonitored in the measurement and inspection programs;the measurement program should be used to confirm theanalysis, but the program (i.e., data acquisition, reduc-tion, interpretation processes) should be sufficientlyflexible to permit definition of any significant vibratorymodes that are present but were not included in theanalysis; the inspection program should be consideredand used as a powerful tool for quantitative (e.g., as anindicator of maximum total relative motion) as well asqualitative (e.g., establishment of boundary conditionsby inspection evidence at component interfaces) verifica-tion of both the analytical and measurement programresults.The original guidelines of Regulatory Guide 1.20 havebeen refined in this revision to incorporate items thatwill expedite review of the applicant's vibration assess-ment program by the NRC staff. Generally, this has beenaccomplished by increased specificity in the guidelinesUSNRC REGULATORY GUIDES Comments should be sent to the Secretary of the Commission. U.S. NuclearRegulatory Guide% ate issud to describe and matte available to the publc Regulatory Commission. Washington, D.C. 20566. Attention Dockelting andmethods acceptable tO the NRC staff of implementing specific pans of the Service Section.Commisson's regulations. In delineate techniques used by the staff in vavlu The guides are Issued in the following ten broad divisionssling specsifc problems or postulated accidents, or to provide guidance to opplicants Regulatory Guides are not substitutes lor regulations. and compliance I. Power Reactors 6, Productsw"th therr is no. required. Methods and solutions dilterent from those set out in 2 Research and Test Reactors 7. Transportationthe gurdes will be acceptable if they provide a basis tor the findings requisita to 3. Fuels and Materials Facilities S. Occupational Healththe tsluence or continuance of a permit or license by the Commission 4. Environmental and Siting 9. Antltrust ReviewComments and suggestions for improvements in these guide% are encourageo S Materials and Plant Protection 10. Gentealat all times. and guides wilt be tewised. as eppropriate, to accommodate cornments and to reflect new informatton or eaperience However, comments on Copies of published guides may be obtained by written request indicating thethins gurde. If recersed within about two months ailts ats issuance. will be par divisions desired to the U.S. Nuclear RegulatotV Commission. Washinglon. 0 C.K cuterly useful in evaluating the need for an early tevismon 2066M. AttentloA. Direitor. Of tice of Standards Development for the vibration analysis, measurement, and inspectionprograms and by inclusion of guidelines for schedulingsignificant phases of the comprehensive vibration assess-ment program.The original guidelines served as the basis for testingmany prototype and similar-to-prototype (referred to inthis guide as non-prototype) reactor internals. Operatingexperience and the tendency for the design of sub-sequent reactor internals to differ somewhat from thatof the initially designated prototypes have, in someinstances, made the basic prototype and non-prototypeclassifications difficult to apply, resulting in the need for* time-consuming case-by-case resolution of reactorinternal classifications and corresponding vibrationassessment programs.This revision expands on the previous classificationsand outlines an appropriate comprehensive vibrationassessment program for each class. The new classifica-tions are defined in regulatory position C.A below. Ingeneral, the expanded classifications and correspondingprograms allow for the use, under certain conditions, ofprototype reactor internals that have experienced someadverse inservice vibration phenomena as limited proto-types and for the use, under certain conditions, ofreactor internals that are in some respects structurallydissimilar from the designated prototype as limitednon-prototypes. The expanded classifications will makethe use of this guide compatible with design andoperating experience. | |||
==C. REGULATORY POSITION== | |||
The classifications provided in regulatory position C.1should be used by the applicant to first categorize thereactor internals according to design, operating param-eters, and the operating experience of potential proto-typed. The appropriate comprehensive vibrationassessment program should then be established from theguidelines specified for that classification in the succeed-ing sections of this guide. The comprehensive vibrationassessment programs outlined in this guide are sum-marized in Figure 1.1. Classification of Reactor Internals Relative to theComprehensive Vibration Assessment Program1.1 Prototype. A reactor internals configuration,that, because of its arrangement, design, size, or operat-ing conditions, represents a first-of-a-kind or uniquedesign for which no Valid Prototype exists.1.2 Valid Prototype. A reactor internals config-uration that has successfully completed a comprehensivevibration assessment program for Prototype reactorinternals and has experienced no adverse inservicevibration phenomena. A Valid Prototype that is sub-sequently modified in design (e.g., as in item 1.3 below)remains a Valid Prototype relative to its original design.1.3 Conditional Prototype. A Valid Prototypethat later experiences adverse inservice vibrationphenomena and subsequently has been modified inarrangement, design, size, or operating conditions isdesignated a Conditional Prototype. Upon satisfyingconditions described elsewhere in this guide, the Condi-tional Prototype serves as the reference design forNon-Prototype, Category Ill and IV, reactor internalsconfigurations.1.4 Non-Prototype, Category 1. A reactor inter-nals configuration with substantially the same arrange-ment, design., size, and operating conditions as aspecified Valid Prototype and for which nominal differ-ences in arrangement, design, size, and operating condi-tions have been shown by test or analysis to have nosignificant effect on the vibratory response andexcitation of those reactor internals important to safety.1.5 Non-Prototype, Category II. A reactorinternals configuration with substantially the same sizeand operating conditions as a specified Valid Prototype,but with some component arrangement or design differ-ences that are shown by t.-st or analysis to have nosignificant effect on the vibratory response and excita-tion of those unmodified reactor internals important tosafety.1.6 Limited Valid Prototype. A Non-Prototype,Category 11 or Ill, reactor internals configuration thathas successfully completed the appropriate comprehen-sive vibration assessment program and has itself experi-enced no adverse inservice vibration phenomena. Anoperating Valid Prototype that has demonstratedextended satisfactory inservice operation subsequent to adesign modification may be considered a Limited ValidPrototype relative to the modified reactor internalsconfiguration. A Conditional Prototype that has demon-strated extended satisfactory inservice operation may beconsidered a Limited Valid Prototype.1.7 Non-Prototype, Category 111. A reactor inter-nals configuration with substantially the same arrange-ment, design, size, and operating conditions as aspecified Conditional Prototype with insufficientoperating history to justify it as a Limited ValidPrototype. Differences in arrangement, design, size, andoperating conditions should be shown by test or analysisto have no significant effect on the vibratory responseand excitation of those reactor internals important tosafety.1.8 Non-Prototype, Category IV. A ieactor inter-nals configuration with substantially the same arrange-ment, design, size, and operating conditions as aspecified Limited Valid Prototype, where nominal differ-1.20-2 01IQDReactor internals configuration for which comprehensivevibration assessment program is defined.Summary of comprehensive vibration assessment programs.Reactor internals reference design which, together with its test and operatingexperience, provides the basis for a specific comprehensive vibration assessmentprogram.Indicates alternative pathsFIGURE I -SUMMARY OF COMPREHENSIVE VIBRATION ASSESSMENT PROGRAMS1.20-3 ences in arrangement, design, size, and operating condi.tions have been shown by test or analysis to have nosignificant effect on the vibratory response and excita-tion of those reactor internals important to safety.Associated with the Prototype and the Category 1, 11,III, and IV Non-Prototype classifications are thecomprehensive vibration assessment programs delineatedin regulatory positions C.2 and C.3 and summarized inFigure 1. The foregoing classifications are definedrelative to the three prototype reference design classifi-cations (i.e., Valid Prototype, Conditional Prototype,Limited Valid Prototype) upon whose design, test, andoperating experience the individual comprehensivevibration assessment programs are based..2. Comprehensive Vibration Assessment Program forPrototype Reactor InternalsThe comprehensive vibration assessment programshould be implemented in conjunction with preopera-tional and initial startup testing. It should consist of avibration analysis, a vibration measurement program, aninspection program, and a correlation of their results.2.1 Vibration Analysis ProgramThe vibration analysis should be performed forthose steady-state and anticipated transient conditionsthat correspond to preoperadional and initial startup testand normal operating conditions. The vibration analysissubmittal should include a summary of:1. The theoretical structural and hydraulicmodels and analytical formulations or scaling laws andscale models used in the analysis.2. The structural and hydraulic system naturalfrequencies and associated mode shapes which may beexcited during steady-state and anticipated transientoperation.3. The estimated random and deterministicforcing functions, including any very-low-frequencycomponents, for steady-state and anticipated transientoperation.4. The calculated structural and hydraulicresponses for steady-state and anticipated transientoperation. (The random, deterministic, overall integratedmaximum response, any very-low-frequency componentsof response, and the level of cumulative fatigue damageshould be identified.)5. A comparison of the calculated structuraland hydraulic responses for preoperational and initialstartup testing with those for normal operation. (Normaloperating conditions that are not accurately or suffi-ciently simulated by the test conditions should beidentified.)6. The anticipated structural or hydraulicvibratory response (defined in terms of frequency,amplitude, and modal contributions) that is appropriateto each of the sensor locations for steady-state andanticipated transient preoperational and startup testconditions.7. The test acceptance criteria with permissibledeviations and the basis for the criteria. (The criteriashould be established in terms of maximum allowableresponse levels in the structure and presented in terms ofmaximum allowable response levels at sensor locations.)2.2 Vibration Measurement ProgramA vibration measurement program should bedeveloped and implemented to verify the structuralintegrity of the reactor internals, to determine themargin of safety associated with steady-state and antici-pated transient conditions for normal operation and toconfirm the results of the vibration analysis. Thevibration measurement program should include adescription of:1. The data acquisition and reduction system,including:a. Transducer types and their specifications,including useful frequency and amplitude ranges.b. Transducer positions, which should besufficient to monitor significant lateral, vertical, andtorsional structural motions of major reactor internalcomponents in shell, beam, and rigid body modes ofvibration, as well as significant hydraulic responses andthose parameters that define the input forcingfunction.c. Precautions being taken to ensure acquisi-tion of quality data (e.g., optimization of signal-to-noiseratio, relationship of recording times to data reductionrequirements, choice of instrumentation system).d. On-line data evaulation system to provideimmediate verification of general quality and level ofdata.e. Procedures for determining frequency,modal content, and maximum values of response.2. Test operating conditions, including:a. All steady-state and transient modes ofoperation.1.20-4 b. The planned duration of all testing in,normal operating modes to ensure that each criticalcomponent will have been subjected to at least 1O0cycles of vibration (i.e., computed at the component'sminimum significant response frequency) prior to thefinal inspection of the reactor internals. (If it is notfeasible to perform an inspection following the accumu-lation of 107 cycles, the structural integrity of thereactor internals should be verified by measurementswhich demonstrate that no significant change in struc-tural response resulting from component damage hasoccurred between the time vibration testing was initiatedand after 107 cycles were accrued.)c. Disposition of fuel assemblies. (Testingshould be performed with the reactor internals impor-tant to safety and the fuel assemblies (or dummyassemblies which provide equivalent dynamic mass andflow characteristics) in position. The test may beconducted without real or dummy fuel assemblies if itcan be shown by analytical or experimental means thatsuch conditions will yield conservative results.)2.3 Inspection ProgramThe inspection program should provide forinspections of the reactor internals prior to and follow-ing operation at those steady-state and transient modesconsistent with the test conditions for regulatoryposition C.2.2.2. The reactor internals should beremoved from the reactor vessel for these inspections. Ifremoval is not feasible, the inspections should beperformed by means of examination equipment appro-priate for in situ inspection. The inspection programshould include:1. A tabulation of all reactor internal compo-nents .,..d iocal areas to be inspected, including:a. All major load-bearing elements of thereactor internals relied upon to retain the core supportstructure in position.b. The lateral, vertical, and torsionalrestraints provided within the vessel.c. Those locking and bolting componentswhose failure could adversely affect the structuralintegrity of the reactor internals.d. Those surfaces that are known to be ormay become contact surfaces during operation.e. Those critical locations on the reactorinternal components as identified by the vibrationanalysis.f. The interior of the reactor vessel forevidence of loose parts or foreign material.2. A tabulation of specific inspection areas thatcan be used to verify segments of the vibration analysisand measurement program.3. A description of the inspection procedure,including the method of examination (e.g., visual andnondestructive surface examinations), method of docu-mentation, access provisions on the reactor internals,and specialized equipment to be employed during theinspections to detect and quantify evidence of theeffects of vibration.2.4 Documentation of ResultsThe results of the vibration analysis, measure-ment, and inspection programs should be reviewed andcorrelated to determine the extent to which the testacceptance criteria are satisfied. A summary of theresults should be submitted to the Commission asfollows:1. If the results of'the comprehensive vibrationassessment program are acceptable, the final reportshould include:a. A description of any deviations from thespecified measurement and inspection programs,including instrumentation reading and inspectionanomalies, instrumentation malfunctions, and deviationsfrom the specified operating conditions,b. A comparison between the measured andanalytically determined modes of structural andhydraulic response (including those parameters fromwhich the input forcing function is determined) for thepurpose of establishing the validity of the analyticaltechnique,c. A determination of the margin of safetyassociated with normal steady-state and anticipatedtransient operation,d. An evaluation of measurements thatexceeded acceptable limits not specified as testacceptance criteria or of observations that were unantici-pated and the disposition of such deviations.2. If (1) inspection of the reactor internalsreveals defects, evidence of unacceptable motion,excessive or undue wear, (2) the results from themeasurement program fail to satisfy the specified testacceptance criteria, or (3) the results from the analysis,measurement, and inspection programs are inconsistent,the final report should also include an evaluation anddescription of the modifications or actions planned inorder to justify the structural adequacy of the reactorinternals.1.20-5 The collection, storage, and maintenance ofall records relevant to the analysis, measurement, andinspection phases of the comprehensive vibration assess-ment program should be consistent with RegulatoryGuide 1.88, "Collection, Storage, and Maintenance ofNuclear Power Plant Quality Assurance Records," whichdescribes a method acceptable to the NRC staff forcomplying with Criterion XVII, "Quality AssuranceRecords," of Appendix B, "Quality Assurance Criteriafor Nuclear Power Plants and Fuel Reprocessing Plants,"to 10 CFR Part 50.effects of such operation on the structural integrity ofthe non-prototype reactor internals should be based onthe results of a comprehensive vibration assessmentprogram developed for the specific non-prototype classi-fication (i.e., Categcry 1, 1I, Ill, or IV). The comprehen-sive vibration assessmcnt programs for non-prototypereactor internals are outlined below. These programsshould be scheduled and documented in accordance withthe guidelines for the program delineated in regulatorypositions C.2.4 and C.2.5 for Prototype reactor inter-nals.2.5 Schedule3.1 Non-Prototype, Category IA schedule should be established and submittedto the Commission during the construction permitreview. The schedule should provide that:1. The reactor internals design will be classifiedin the Preliminary Safety Analysis Report (PSAR) as aprototype or a specific category of non-prototype. (Ifthe internals are classified as non-prototype, the appli-cant should identify the applicable prototype reactorinternals in the PSAR. Experimental or analyticaljustification for the non-prototype classification shouldbe presented during the construction permit review.)2. A commitment will be established duringthe construction permit review regarding the scope ofthe comprehensive vibration assessment program.3. A description of the vibration measurementand inspection phases of the comprehensive vibrationassessment program will be submitted to the Com-mission in sufficient time to permit utilization ofCommission recommendations. (A 90-day comment andreview period by the staff should be assumid by theapplic~ant for scheduling purposes.)4. A summary of the vibration analysis pro-gram will be submitted to the Commission a minimumof 60 days prior to submittal of the description of thevibration measurement and inspection programs.5. The final report, which summarizes theresults of the vibration analysis, measurement, andinspection programs, will be presented to the Com-mission within 120 days of the completion of vibrationtesting,3. Comprehensive Vibration Assessment Programsfor Non-Prototype Reactor InternalsNon-prototype reactor internals important tosafety should be subjected during the preoperational andinitial startup test program to all significant flow modesassociated with normal steady-state and anticipatedtransient operation under the same test conditionsimposed on the applicable prototype. Evaluation of the3.1.1 Vibration Analysis ProgramThe Valid Prototype should be specified andsufficient evidence should be provided to support theclassification Non-Prototype, Category 1.The vibration analysis for the Valid Proto-type, which includes a summary of the anticipatedstructural and hydraulic response and test acceptancecriteria, should be modified to account for the nominaldifferences that may exist between the Non-Prototype,Category I, and Valid Prototype reactor internals.3.1.2 Vibration Measurement ProgramThe vibration measurement program may beomitted if the inspection program is implemented.If a measurement program is implemented inlieu of an inspection program, sufficient and appropriateinstrumentation should be incorporated to verify thatthe vibratory response of the Non-Prototype, Category 1,reactor internals is consistent with the results of thevibration analysis, test acceptance criteria, and thevibratory response observed in the Valid Prototype. Thevibration measurement program should include adescription of the data acquisition and reductionsystems and test operating conditions consistent withthe general guidelines for the vibration measurementprogram delineated in regulatory position C.2.2 forPrototype reactor internals.3.1.3 Inspection ProgramIf an inspection program is implemented inlieu of a vibration measurement program, the guidelinesfor the inspection program delineated in regulatoryposition C.2.3 for Prototype reactor internals should befollowed.The inspection program may be omitted ifthe vibration measurement program is implemented.However, if significant discrepancies exist betweenanticipated and measured responses for specific compo-nents, those components should be removed froin the1.20-6 reactor vessel and a visual examination performed.Components for which removal is not feasible should beexamined in situ by means of appropriate inspectionequipment. In any case, the interior of the reactor vesselshould be visually checked for loose parts and foreignmaterial.3.2 Non-Prototype, Category 113.2.1 Vibration Analysis ProgramThe Valid Prototype should be specified,and sufficient evidence should be provided to supportthe classification Non-Prototype, Category II, whichrequires demonstrating that the structural differencesthat exist between the Non-Prototype, Category II,and Valid Prototype reactor internals have no significanteffect on the vibratory response and excitation of thoseunmodified Non-Prototype, Category Ii, components.The vibration analysis for the Valid Proto-type, which includes a summary of the anticipatedstructural and hydraulic response and test acceptancecriteria, should be modified to account for the structuraldifferences that exist between the Valid Prototype andNon-Prototype, Category !1, reactor internals.Test acceptance criteria should specificallybe established for those Non-Prototype, Category II,reactor internal components with structural differencesrelative to the Valid Prototype.3.2.2 Vibration Measurement ProgramA vibration measurement program should beimplemented on the Non-Prototype, Category II, reactorinternals during preoperational and initial startuptesting.The vibration measurement program shouldinclude a description of the data acquisition andreduction systems and test operating conditions con-sistent with the general guidelines for the vibrationmeasurement program delineated in regulatory positionC.2.2 for Prototype reactor internals.Sufficient and appropriate instrumentationshould be used to define the vibratory response (i.e.,frequency, amplitude, modal content) of those reactorinternal components important to safety that have beenmodified relative to the Valid Prototype for the purposeof demonstrating that the test acceptance criteria aresatisfied and establishing the margin of safety.Sufficient and appropriate instrumentationshould be used to monitor those reactor internalcomponents important to safety that have not beenmoc'ified relative to the Valid Prototype to confirm thatthe vibratory response of such components complieswith the guidelines for Non-Prototype, Category 11,reactor internals and is consistent with the resultsobtained for similar components during the measure-ment program on the Valid Prototype.3.2.3 Inspection ProgramAn inspection program that follows theguidelines for the inspection program delineated inregulatory position C.2.3 for Prototype reactor internalsshould be implemented.3.3 Non-Prototype, Category III3.3.1 Vibration Analysis ProgramThe Conditional Prototype should bespecified, and sufficient analytical or experimentalevidence should be provided to support the classificationNon-Prototype, Category I11, as well as to demonstratethe applicability of data from the vibration measurementprogram on the Prototype to the Conditional Prototype.It should be demonstrated that:1. The Conditional Prototype is sub-stantially similar in arrangement, design, size, andoperating conditions to the Non-Prototype, Category Ill.reactor internals.2. Response modes attributable to theinservice vibration problems and ensuing component oroperational modifications do not significantly affect theapplicability of the results of the vibration measurementprogram on the Prototype to the Conditional Prototype,or response modes attributable to the inservice vibrationproblems and ensuing component or operational modifi-cations do affect the applicability of the results of thevibration measurement program on the Prototype to theConditional Prototype, but the effects are limited tostructural components and response modes that permitclear separation of these effects from other results of thevibration measurement program.Details concerning the adverse vibrationexperience of the Conditional Prototype should beprovided, as should experimental or analytical informa-tion which demonstrates that the vibration problemsassociated with the Conditional Prototype have beencorrected for both it and the applicable Non-Prototype.Category Ill, reactor internals.The vibration analysis on the Prototype tothe Conditional Prototype, which includes a summary ot'the anticipated structural and hydraulic response andtest acceptance criteria for the measurement program onthe Prototype, should be modified to account for thecomponent or operational modifications applicable tothe Conditional Prototype and Non-Prototype, CategoryIll, reactor internals..20-7 Test acceptance criteria, with permissibledeviations, should be specified for reactor internalcomponents important to safety. Each componentshould be categorized according to whether the resultsfrom the vibration measurement program on tie Proto-type to the Conditional Prototype are applicable.3.3.2 Vibration Measurement ProgramA vibration measurement program should beimplemented on the Non-Prototype, Category III,reactor internals during preoperational and initial startuptesting.Sufficient and appropriate instrumentationshould be used to define the vibratory response of thosereactor components important to safety which, becauseof structural or operational modifications relative to theoriginal design of the Conditional Prototype, areexpected to have response characteristics substantiallydifferent from those measured for that componentduring the vibration measurement program on thePrototype to the Conditional Prototype.All other components should be monitoredwith sufficient and appropriate instrumentation to con-firm that the measured response for each component issubstantially similar to that obtained during the vibia-tion measurement program on the Prototype to theConditional Prototype.The vibration measurement program shouldsatisfy the general guidelines for a Prototype measure-ment program as delineated in regulatory position C.2.2.3.3.3 Inspection ProgramAn inspection program that satisfies theguidelines for the inspection program delineated inregulatory position C.2.3 for PrototN pe reactor internalsshould be implemented.3.4 Non-Prototype, Category IV3.4.1 Vibration Analysis ProgramThe Limited Valid Prototype should bespecified, and sufficient evidence should be provided tosupport the classification Non-Prototype, Category IV.3.4.2 Vibration Measurement ProgramA vibration measurement program may beomitted if the inspection program is implemented.If a measurement program is implemented inlieu of an inspection program, sufficient and appropriateinstrumentation should be incorporated to verify thatthe vibratory response of the Non-Prototype, CategoryIV, reactor internals is consistent with the results of thevibration analysis. test acceptance criteria, and thevibratory response for the referenced Limited ValidPrototype.The vibration measurement program shouldbe consistent with the guidelines delineated in regulatoryposition C.3.1.2 for the measurement program forNon-Prototype, Category 1, reactor internals.3.4.3 Inspection ProgramIf an inspection program is implemented inlieu of a vibration measurement program, the guidelinesfor the inspection program delineated in regulatoryposition C.3.1.3 for Non-Prototype, Category 1, reactorinternals should be followed. | |||
==D. IMPLEMENTATION== | |||
The purpose of this section is to provide guidance toapplicants and licensees regarding the NRC staff's plansfor utilizing this regulatory guide.Except in those cases in which the applicant proposesan acceptable alternative method for complying withspc-:ified poitions of the Commission's regulations, themethod described herein will be used in the evaluationof submittals for operating license or constructionpermit applications docketed after August 21, 1975.If an applicant wishes to use this regulatory guide indeveloping submittals for applications docketed on urbefore August 21, 1975, the pertinent portions of theapplication will be evaluated on the basis of this guide.d1.20-84}} | |||
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Revision as of 22:37, 5 March 2018
| ML13350A367 | |
| Person / Time | |
|---|---|
| Issue date: | 06/30/1975 |
| From: | NRC/OSD |
| To: | |
| References | |
| RG-1.020, Rev. 1 | |
| Download: ML13350A367 (8) | |
U.S. NUCLEAR REGULATORY COMMISSIONREGULATORY GUIDEOFFICE OF STANDARDS DEVELOPMENTREGULATORY GUIDE 1.20COMPREHENSIVE VIBRATION ASSESSMENT PROGRAMFOR REACTOR INTERNALS DURINGPREOPERATIONAL AND INITIAL STARTUP TESTINGRevision 1June 1975
A. INTRODUCTION
Criterion 1, "Quality Standards and Records," ofAppendix A, "General Design Criteria for Nuclear'PowerPlants," to 10 CFR Part 50, "Licensing of Productionand Utilization Facilities," requires that structures,systems, and components important to safety bedesigned, fabricated, erected, and tested to qualitystandards commensurate with the importance of thesafety functions to be performed. Section 50.34, "Con-tents of Applications; Technical Information," of 10CFR Part 50 requires the applicant to determine and tospecify the margin of safety associated with normaloperation and anticipated operating transients.This guide presents a method acceptable to the NRCstaff for implementing the above requirements withrespect to the internals of light-water-cooled reactors'during preoperational and initial startup testing.2 Inser-vice inspections and inservice monitoring programs toverify that the reactor internal components have notbeen subjected to structural degradation as a result ofvibration during normal reactor operation are notcovered by this guide.'Reactor internals, as used in this regulatory guide, comprisecore support structures and adjoining internal structures. Coresupport and internal structures are defined in Article NG-I 120of Section 111 (Nuclear Power Plant Components) of the ASMEBoiler and Pressure Vessel Code.kConsistent with Regulatory Guide 1.68, "Preoperational andInitial Startup Test Programs for Water-Cooled PowerReactors," preoperational testing as used in this guide consistsof those tests conducted prior to fuel loading, and intial startuptesting refers to those tests performed after fuel loading.
B. DISCUSSION
Reactor internals important to safety are designed toaccommodate steady-state and transient vibratory loadsfor the service life of the reactor. This guide presents acomprehensive vibration assessment program for use inverifying the structural integrity of the reactor internalsfor flow-induced vibrations prior to commercial opera-tion. The overall program includes individual analytical,measurement, and inspection programs. The term "com-prehensive" appears in the title of the overall program toemphasize that the individual programs should be usedcooperatively to verify structural integrity and to estab-lish the margin of safety. For example, the analyticalprogram not only should be used to provide theoreticalverification of structural integrity but also should be thebasis for the choice of components and areas to bemonitored in the measurement and inspection programs;the measurement program should be used to confirm theanalysis, but the program (i.e., data acquisition, reduc-tion, interpretation processes) should be sufficientlyflexible to permit definition of any significant vibratorymodes that are present but were not included in theanalysis; the inspection program should be consideredand used as a powerful tool for quantitative (e.g., as anindicator of maximum total relative motion) as well asqualitative (e.g., establishment of boundary conditionsby inspection evidence at component interfaces) verifica-tion of both the analytical and measurement programresults.The original guidelines of Regulatory Guide 1.20 havebeen refined in this revision to incorporate items thatwill expedite review of the applicant's vibration assess-ment program by the NRC staff. Generally, this has beenaccomplished by increased specificity in the guidelinesUSNRC REGULATORY GUIDES Comments should be sent to the Secretary of the Commission. U.S. NuclearRegulatory Guide% ate issud to describe and matte available to the publc Regulatory Commission. Washington, D.C. 20566. Attention Dockelting andmethods acceptable tO the NRC staff of implementing specific pans of the Service Section.Commisson's regulations. In delineate techniques used by the staff in vavlu The guides are Issued in the following ten broad divisionssling specsifc problems or postulated accidents, or to provide guidance to opplicants Regulatory Guides are not substitutes lor regulations. and compliance I. Power Reactors 6, Productsw"th therr is no. required. Methods and solutions dilterent from those set out in 2 Research and Test Reactors 7. Transportationthe gurdes will be acceptable if they provide a basis tor the findings requisita to 3. Fuels and Materials Facilities S. Occupational Healththe tsluence or continuance of a permit or license by the Commission 4. Environmental and Siting 9. Antltrust ReviewComments and suggestions for improvements in these guide% are encourageo S Materials and Plant Protection 10. Gentealat all times. and guides wilt be tewised. as eppropriate, to accommodate cornments and to reflect new informatton or eaperience However, comments on Copies of published guides may be obtained by written request indicating thethins gurde. If recersed within about two months ailts ats issuance. will be par divisions desired to the U.S. Nuclear RegulatotV Commission. Washinglon. 0 C.K cuterly useful in evaluating the need for an early tevismon 2066M. AttentloA. Direitor. Of tice of Standards Development for the vibration analysis, measurement, and inspectionprograms and by inclusion of guidelines for schedulingsignificant phases of the comprehensive vibration assess-ment program.The original guidelines served as the basis for testingmany prototype and similar-to-prototype (referred to inthis guide as non-prototype) reactor internals. Operatingexperience and the tendency for the design of sub-sequent reactor internals to differ somewhat from thatof the initially designated prototypes have, in someinstances, made the basic prototype and non-prototypeclassifications difficult to apply, resulting in the need for* time-consuming case-by-case resolution of reactorinternal classifications and corresponding vibrationassessment programs.This revision expands on the previous classificationsand outlines an appropriate comprehensive vibrationassessment program for each class. The new classifica-tions are defined in regulatory position C.A below. Ingeneral, the expanded classifications and correspondingprograms allow for the use, under certain conditions, ofprototype reactor internals that have experienced someadverse inservice vibration phenomena as limited proto-types and for the use, under certain conditions, ofreactor internals that are in some respects structurallydissimilar from the designated prototype as limitednon-prototypes. The expanded classifications will makethe use of this guide compatible with design andoperating experience.
C. REGULATORY POSITION
The classifications provided in regulatory position C.1should be used by the applicant to first categorize thereactor internals according to design, operating param-eters, and the operating experience of potential proto-typed. The appropriate comprehensive vibrationassessment program should then be established from theguidelines specified for that classification in the succeed-ing sections of this guide. The comprehensive vibrationassessment programs outlined in this guide are sum-marized in Figure 1.1. Classification of Reactor Internals Relative to theComprehensive Vibration Assessment Program1.1 Prototype. A reactor internals configuration,that, because of its arrangement, design, size, or operat-ing conditions, represents a first-of-a-kind or uniquedesign for which no Valid Prototype exists.1.2 Valid Prototype. A reactor internals config-uration that has successfully completed a comprehensivevibration assessment program for Prototype reactorinternals and has experienced no adverse inservicevibration phenomena. A Valid Prototype that is sub-sequently modified in design (e.g., as in item 1.3 below)remains a Valid Prototype relative to its original design.1.3 Conditional Prototype. A Valid Prototypethat later experiences adverse inservice vibrationphenomena and subsequently has been modified inarrangement, design, size, or operating conditions isdesignated a Conditional Prototype. Upon satisfyingconditions described elsewhere in this guide, the Condi-tional Prototype serves as the reference design forNon-Prototype, Category Ill and IV, reactor internalsconfigurations.1.4 Non-Prototype, Category 1. A reactor inter-nals configuration with substantially the same arrange-ment, design., size, and operating conditions as aspecified Valid Prototype and for which nominal differ-ences in arrangement, design, size, and operating condi-tions have been shown by test or analysis to have nosignificant effect on the vibratory response andexcitation of those reactor internals important to safety.1.5 Non-Prototype, Category II. A reactorinternals configuration with substantially the same sizeand operating conditions as a specified Valid Prototype,but with some component arrangement or design differ-ences that are shown by t.-st or analysis to have nosignificant effect on the vibratory response and excita-tion of those unmodified reactor internals important tosafety.1.6 Limited Valid Prototype. A Non-Prototype,Category 11 or Ill, reactor internals configuration thathas successfully completed the appropriate comprehen-sive vibration assessment program and has itself experi-enced no adverse inservice vibration phenomena. Anoperating Valid Prototype that has demonstratedextended satisfactory inservice operation subsequent to adesign modification may be considered a Limited ValidPrototype relative to the modified reactor internalsconfiguration. A Conditional Prototype that has demon-strated extended satisfactory inservice operation may beconsidered a Limited Valid Prototype.1.7 Non-Prototype, Category 111. A reactor inter-nals configuration with substantially the same arrange-ment, design, size, and operating conditions as aspecified Conditional Prototype with insufficientoperating history to justify it as a Limited ValidPrototype. Differences in arrangement, design, size, andoperating conditions should be shown by test or analysisto have no significant effect on the vibratory responseand excitation of those reactor internals important tosafety.1.8 Non-Prototype, Category IV. A ieactor inter-nals configuration with substantially the same arrange-ment, design, size, and operating conditions as aspecified Limited Valid Prototype, where nominal differ-1.20-2 01IQDReactor internals configuration for which comprehensivevibration assessment program is defined.Summary of comprehensive vibration assessment programs.Reactor internals reference design which, together with its test and operatingexperience, provides the basis for a specific comprehensive vibration assessmentprogram.Indicates alternative pathsFIGURE I -SUMMARY OF COMPREHENSIVE VIBRATION ASSESSMENT PROGRAMS1.20-3 ences in arrangement, design, size, and operating condi.tions have been shown by test or analysis to have nosignificant effect on the vibratory response and excita-tion of those reactor internals important to safety.Associated with the Prototype and the Category 1, 11,III, and IV Non-Prototype classifications are thecomprehensive vibration assessment programs delineatedin regulatory positions C.2 and C.3 and summarized inFigure 1. The foregoing classifications are definedrelative to the three prototype reference design classifi-cations (i.e., Valid Prototype, Conditional Prototype,Limited Valid Prototype) upon whose design, test, andoperating experience the individual comprehensivevibration assessment programs are based..2. Comprehensive Vibration Assessment Program forPrototype Reactor InternalsThe comprehensive vibration assessment programshould be implemented in conjunction with preopera-tional and initial startup testing. It should consist of avibration analysis, a vibration measurement program, aninspection program, and a correlation of their results.2.1 Vibration Analysis ProgramThe vibration analysis should be performed forthose steady-state and anticipated transient conditionsthat correspond to preoperadional and initial startup testand normal operating conditions. The vibration analysissubmittal should include a summary of:1. The theoretical structural and hydraulicmodels and analytical formulations or scaling laws andscale models used in the analysis.2. The structural and hydraulic system naturalfrequencies and associated mode shapes which may beexcited during steady-state and anticipated transientoperation.3. The estimated random and deterministicforcing functions, including any very-low-frequencycomponents, for steady-state and anticipated transientoperation.4. The calculated structural and hydraulicresponses for steady-state and anticipated transientoperation. (The random, deterministic, overall integratedmaximum response, any very-low-frequency componentsof response, and the level of cumulative fatigue damageshould be identified.)5. A comparison of the calculated structuraland hydraulic responses for preoperational and initialstartup testing with those for normal operation. (Normaloperating conditions that are not accurately or suffi-ciently simulated by the test conditions should beidentified.)6. The anticipated structural or hydraulicvibratory response (defined in terms of frequency,amplitude, and modal contributions) that is appropriateto each of the sensor locations for steady-state andanticipated transient preoperational and startup testconditions.7. The test acceptance criteria with permissibledeviations and the basis for the criteria. (The criteriashould be established in terms of maximum allowableresponse levels in the structure and presented in terms ofmaximum allowable response levels at sensor locations.)2.2 Vibration Measurement ProgramA vibration measurement program should bedeveloped and implemented to verify the structuralintegrity of the reactor internals, to determine themargin of safety associated with steady-state and antici-pated transient conditions for normal operation and toconfirm the results of the vibration analysis. Thevibration measurement program should include adescription of:1. The data acquisition and reduction system,including:a. Transducer types and their specifications,including useful frequency and amplitude ranges.b. Transducer positions, which should besufficient to monitor significant lateral, vertical, andtorsional structural motions of major reactor internalcomponents in shell, beam, and rigid body modes ofvibration, as well as significant hydraulic responses andthose parameters that define the input forcingfunction.c. Precautions being taken to ensure acquisi-tion of quality data (e.g., optimization of signal-to-noiseratio, relationship of recording times to data reductionrequirements, choice of instrumentation system).d. On-line data evaulation system to provideimmediate verification of general quality and level ofdata.e. Procedures for determining frequency,modal content, and maximum values of response.2. Test operating conditions, including:a. All steady-state and transient modes ofoperation.1.20-4 b. The planned duration of all testing in,normal operating modes to ensure that each criticalcomponent will have been subjected to at least 1O0cycles of vibration (i.e., computed at the component'sminimum significant response frequency) prior to thefinal inspection of the reactor internals. (If it is notfeasible to perform an inspection following the accumu-lation of 107 cycles, the structural integrity of thereactor internals should be verified by measurementswhich demonstrate that no significant change in struc-tural response resulting from component damage hasoccurred between the time vibration testing was initiatedand after 107 cycles were accrued.)c. Disposition of fuel assemblies. (Testingshould be performed with the reactor internals impor-tant to safety and the fuel assemblies (or dummyassemblies which provide equivalent dynamic mass andflow characteristics) in position. The test may beconducted without real or dummy fuel assemblies if itcan be shown by analytical or experimental means thatsuch conditions will yield conservative results.)2.3 Inspection ProgramThe inspection program should provide forinspections of the reactor internals prior to and follow-ing operation at those steady-state and transient modesconsistent with the test conditions for regulatoryposition C.2.2.2. The reactor internals should beremoved from the reactor vessel for these inspections. Ifremoval is not feasible, the inspections should beperformed by means of examination equipment appro-priate for in situ inspection. The inspection programshould include:1. A tabulation of all reactor internal compo-nents .,..d iocal areas to be inspected, including:a. All major load-bearing elements of thereactor internals relied upon to retain the core supportstructure in position.b. The lateral, vertical, and torsionalrestraints provided within the vessel.c. Those locking and bolting componentswhose failure could adversely affect the structuralintegrity of the reactor internals.d. Those surfaces that are known to be ormay become contact surfaces during operation.e. Those critical locations on the reactorinternal components as identified by the vibrationanalysis.f. The interior of the reactor vessel forevidence of loose parts or foreign material.2. A tabulation of specific inspection areas thatcan be used to verify segments of the vibration analysisand measurement program.3. A description of the inspection procedure,including the method of examination (e.g., visual andnondestructive surface examinations), method of docu-mentation, access provisions on the reactor internals,and specialized equipment to be employed during theinspections to detect and quantify evidence of theeffects of vibration.2.4 Documentation of ResultsThe results of the vibration analysis, measure-ment, and inspection programs should be reviewed andcorrelated to determine the extent to which the testacceptance criteria are satisfied. A summary of theresults should be submitted to the Commission asfollows:1. If the results of'the comprehensive vibrationassessment program are acceptable, the final reportshould include:a. A description of any deviations from thespecified measurement and inspection programs,including instrumentation reading and inspectionanomalies, instrumentation malfunctions, and deviationsfrom the specified operating conditions,b. A comparison between the measured andanalytically determined modes of structural andhydraulic response (including those parameters fromwhich the input forcing function is determined) for thepurpose of establishing the validity of the analyticaltechnique,c. A determination of the margin of safetyassociated with normal steady-state and anticipatedtransient operation,d. An evaluation of measurements thatexceeded acceptable limits not specified as testacceptance criteria or of observations that were unantici-pated and the disposition of such deviations.2. If (1) inspection of the reactor internalsreveals defects, evidence of unacceptable motion,excessive or undue wear, (2) the results from themeasurement program fail to satisfy the specified testacceptance criteria, or (3) the results from the analysis,measurement, and inspection programs are inconsistent,the final report should also include an evaluation anddescription of the modifications or actions planned inorder to justify the structural adequacy of the reactorinternals.1.20-5 The collection, storage, and maintenance ofall records relevant to the analysis, measurement, andinspection phases of the comprehensive vibration assess-ment program should be consistent with RegulatoryGuide 1.88, "Collection, Storage, and Maintenance ofNuclear Power Plant Quality Assurance Records," whichdescribes a method acceptable to the NRC staff forcomplying with Criterion XVII, "Quality AssuranceRecords," of Appendix B, "Quality Assurance Criteriafor Nuclear Power Plants and Fuel Reprocessing Plants,"to 10 CFR Part 50.effects of such operation on the structural integrity ofthe non-prototype reactor internals should be based onthe results of a comprehensive vibration assessmentprogram developed for the specific non-prototype classi-fication (i.e., Categcry 1, 1I, Ill, or IV). The comprehen-sive vibration assessmcnt programs for non-prototypereactor internals are outlined below. These programsshould be scheduled and documented in accordance withthe guidelines for the program delineated in regulatorypositions C.2.4 and C.2.5 for Prototype reactor inter-nals.2.5 Schedule3.1 Non-Prototype, Category IA schedule should be established and submittedto the Commission during the construction permitreview. The schedule should provide that:1. The reactor internals design will be classifiedin the Preliminary Safety Analysis Report (PSAR) as aprototype or a specific category of non-prototype. (Ifthe internals are classified as non-prototype, the appli-cant should identify the applicable prototype reactorinternals in the PSAR. Experimental or analyticaljustification for the non-prototype classification shouldbe presented during the construction permit review.)2. A commitment will be established duringthe construction permit review regarding the scope ofthe comprehensive vibration assessment program.3. A description of the vibration measurementand inspection phases of the comprehensive vibrationassessment program will be submitted to the Com-mission in sufficient time to permit utilization ofCommission recommendations. (A 90-day comment andreview period by the staff should be assumid by theapplic~ant for scheduling purposes.)4. A summary of the vibration analysis pro-gram will be submitted to the Commission a minimumof 60 days prior to submittal of the description of thevibration measurement and inspection programs.5. The final report, which summarizes theresults of the vibration analysis, measurement, andinspection programs, will be presented to the Com-mission within 120 days of the completion of vibrationtesting,3. Comprehensive Vibration Assessment Programsfor Non-Prototype Reactor InternalsNon-prototype reactor internals important tosafety should be subjected during the preoperational andinitial startup test program to all significant flow modesassociated with normal steady-state and anticipatedtransient operation under the same test conditionsimposed on the applicable prototype. Evaluation of the3.1.1 Vibration Analysis ProgramThe Valid Prototype should be specified andsufficient evidence should be provided to support theclassification Non-Prototype, Category 1.The vibration analysis for the Valid Proto-type, which includes a summary of the anticipatedstructural and hydraulic response and test acceptancecriteria, should be modified to account for the nominaldifferences that may exist between the Non-Prototype,Category I, and Valid Prototype reactor internals.3.1.2 Vibration Measurement ProgramThe vibration measurement program may beomitted if the inspection program is implemented.If a measurement program is implemented inlieu of an inspection program, sufficient and appropriateinstrumentation should be incorporated to verify thatthe vibratory response of the Non-Prototype, Category 1,reactor internals is consistent with the results of thevibration analysis, test acceptance criteria, and thevibratory response observed in the Valid Prototype. Thevibration measurement program should include adescription of the data acquisition and reductionsystems and test operating conditions consistent withthe general guidelines for the vibration measurementprogram delineated in regulatory position C.2.2 forPrototype reactor internals.3.1.3 Inspection ProgramIf an inspection program is implemented inlieu of a vibration measurement program, the guidelinesfor the inspection program delineated in regulatoryposition C.2.3 for Prototype reactor internals should befollowed.The inspection program may be omitted ifthe vibration measurement program is implemented.However, if significant discrepancies exist betweenanticipated and measured responses for specific compo-nents, those components should be removed froin the1.20-6 reactor vessel and a visual examination performed.Components for which removal is not feasible should beexamined in situ by means of appropriate inspectionequipment. In any case, the interior of the reactor vesselshould be visually checked for loose parts and foreignmaterial.3.2 Non-Prototype, Category 113.2.1 Vibration Analysis ProgramThe Valid Prototype should be specified,and sufficient evidence should be provided to supportthe classification Non-Prototype, Category II, whichrequires demonstrating that the structural differencesthat exist between the Non-Prototype, Category II,and Valid Prototype reactor internals have no significanteffect on the vibratory response and excitation of thoseunmodified Non-Prototype, Category Ii, components.The vibration analysis for the Valid Proto-type, which includes a summary of the anticipatedstructural and hydraulic response and test acceptancecriteria, should be modified to account for the structuraldifferences that exist between the Valid Prototype andNon-Prototype, Category !1, reactor internals.Test acceptance criteria should specificallybe established for those Non-Prototype, Category II,reactor internal components with structural differencesrelative to the Valid Prototype.3.2.2 Vibration Measurement ProgramA vibration measurement program should beimplemented on the Non-Prototype, Category II, reactorinternals during preoperational and initial startuptesting.The vibration measurement program shouldinclude a description of the data acquisition andreduction systems and test operating conditions con-sistent with the general guidelines for the vibrationmeasurement program delineated in regulatory positionC.2.2 for Prototype reactor internals.Sufficient and appropriate instrumentationshould be used to define the vibratory response (i.e.,frequency, amplitude, modal content) of those reactorinternal components important to safety that have beenmodified relative to the Valid Prototype for the purposeof demonstrating that the test acceptance criteria aresatisfied and establishing the margin of safety.Sufficient and appropriate instrumentationshould be used to monitor those reactor internalcomponents important to safety that have not beenmoc'ified relative to the Valid Prototype to confirm thatthe vibratory response of such components complieswith the guidelines for Non-Prototype, Category 11,reactor internals and is consistent with the resultsobtained for similar components during the measure-ment program on the Valid Prototype.3.2.3 Inspection ProgramAn inspection program that follows theguidelines for the inspection program delineated inregulatory position C.2.3 for Prototype reactor internalsshould be implemented.3.3 Non-Prototype, Category III3.3.1 Vibration Analysis ProgramThe Conditional Prototype should bespecified, and sufficient analytical or experimentalevidence should be provided to support the classificationNon-Prototype, Category I11, as well as to demonstratethe applicability of data from the vibration measurementprogram on the Prototype to the Conditional Prototype.It should be demonstrated that:1. The Conditional Prototype is sub-stantially similar in arrangement, design, size, andoperating conditions to the Non-Prototype, Category Ill.reactor internals.2. Response modes attributable to theinservice vibration problems and ensuing component oroperational modifications do not significantly affect theapplicability of the results of the vibration measurementprogram on the Prototype to the Conditional Prototype,or response modes attributable to the inservice vibrationproblems and ensuing component or operational modifi-cations do affect the applicability of the results of thevibration measurement program on the Prototype to theConditional Prototype, but the effects are limited tostructural components and response modes that permitclear separation of these effects from other results of thevibration measurement program.Details concerning the adverse vibrationexperience of the Conditional Prototype should beprovided, as should experimental or analytical informa-tion which demonstrates that the vibration problemsassociated with the Conditional Prototype have beencorrected for both it and the applicable Non-Prototype.Category Ill, reactor internals.The vibration analysis on the Prototype tothe Conditional Prototype, which includes a summary ot'the anticipated structural and hydraulic response andtest acceptance criteria for the measurement program onthe Prototype, should be modified to account for thecomponent or operational modifications applicable tothe Conditional Prototype and Non-Prototype, CategoryIll, reactor internals..20-7 Test acceptance criteria, with permissibledeviations, should be specified for reactor internalcomponents important to safety. Each componentshould be categorized according to whether the resultsfrom the vibration measurement program on tie Proto-type to the Conditional Prototype are applicable.3.3.2 Vibration Measurement ProgramA vibration measurement program should beimplemented on the Non-Prototype, Category III,reactor internals during preoperational and initial startuptesting.Sufficient and appropriate instrumentationshould be used to define the vibratory response of thosereactor components important to safety which, becauseof structural or operational modifications relative to theoriginal design of the Conditional Prototype, areexpected to have response characteristics substantiallydifferent from those measured for that componentduring the vibration measurement program on thePrototype to the Conditional Prototype.All other components should be monitoredwith sufficient and appropriate instrumentation to con-firm that the measured response for each component issubstantially similar to that obtained during the vibia-tion measurement program on the Prototype to theConditional Prototype.The vibration measurement program shouldsatisfy the general guidelines for a Prototype measure-ment program as delineated in regulatory position C.2.2.3.3.3 Inspection ProgramAn inspection program that satisfies theguidelines for the inspection program delineated inregulatory position C.2.3 for PrototN pe reactor internalsshould be implemented.3.4 Non-Prototype, Category IV3.4.1 Vibration Analysis ProgramThe Limited Valid Prototype should bespecified, and sufficient evidence should be provided tosupport the classification Non-Prototype, Category IV.3.4.2 Vibration Measurement ProgramA vibration measurement program may beomitted if the inspection program is implemented.If a measurement program is implemented inlieu of an inspection program, sufficient and appropriateinstrumentation should be incorporated to verify thatthe vibratory response of the Non-Prototype, CategoryIV, reactor internals is consistent with the results of thevibration analysis. test acceptance criteria, and thevibratory response for the referenced Limited ValidPrototype.The vibration measurement program shouldbe consistent with the guidelines delineated in regulatoryposition C.3.1.2 for the measurement program forNon-Prototype, Category 1, reactor internals.3.4.3 Inspection ProgramIf an inspection program is implemented inlieu of a vibration measurement program, the guidelinesfor the inspection program delineated in regulatoryposition C.3.1.3 for Non-Prototype, Category 1, reactorinternals should be followed.
D. IMPLEMENTATION
The purpose of this section is to provide guidance toapplicants and licensees regarding the NRC staff's plansfor utilizing this regulatory guide.Except in those cases in which the applicant proposesan acceptable alternative method for complying withspc-:ified poitions of the Commission's regulations, themethod described herein will be used in the evaluationof submittals for operating license or constructionpermit applications docketed after August 21, 1975.If an applicant wishes to use this regulatory guide indeveloping submittals for applications docketed on urbefore August 21, 1975, the pertinent portions of theapplication will be evaluated on the basis of this guide.d1.20-84