Regulatory Guide 1.20: Difference between revisions

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{{#Wiki_filter:Revision 2 U.S. NUCLEAR REGULATORY COMMISSION                                                                                                                   May 1976 REGULATORY GUIDE
{{#Wiki_filter:U.S. NUCLEAR REGULATORY COMMISSION  
        OFFICE OF STANDARDS DEVELOPMENT
REGULATORY GUIDE  
                                                                        REGULATORY GUIDE 1.20
OFFICE OF STANDARDS DEVELOPMENT  
                                        COMPREHENSIVE VIBRATION ASSESSMENT PROGRAM
REGULATORY GUIDE 1.20  
                                                          FOR REACTOR INTERNALS DURING
COMPREHENSIVE VIBRATION ASSESSMENT PROGRAM  
                                          PREOPERATIONAL AND INITIAL STARTUP TESTING
FOR REACTOR INTERNALS DURING  
PREOPERATIONAL AND INITIAL STARTUP TESTING


==A. INTRODUCTION==
==A. INTRODUCTION==
Criterion 1, "Quality Standards and Records," of Appendix A, "General Design Criteria for Nuclear Power Plants," to 10 CFR Part 50, "Licensing of Production and Utilization Facilities,"
requires that structures, systems, and components important to safety be designed, fabricated, erected, and tested to quality standards commensurate with the importance of the safety functions to be performed. Section 50.34, "Con tents of Applications; Technical Information," of 10
CFR Part 50 requires the applicant to determine and to specify the margin of safety associated with normal operation and anticipated operating transients.
This guide presents a method acceptable to the NRC
*-'
staff for implementing the above requirements with respect to the internals of light-water-cooled reactors'
during preoperational and initial startup testing.2 Inser vice inspections and inservice monitoring programs to verify that the reactor internal components have not been subjected to structural degradation as a result of vibration during normal reactor operation are not I covered by this guide. The Advisory Committee on Reactor Safeguards has been consulted concerning this guide and has concurred in the Regulatory Position.
lReactor internals, as used in this regulatory guide, comprise core support structures and adjoining internal structures. Core support and internal structures are defined in Article NG-1120
of Section III (Nuclear Power Plant Components) of the ASME
Boiler and Pressure Vessel Code.
konsistent with Regulatory Guide 1.68, "Preoperational and Initial Startup Test Programs for Water-Cooled Power Reactors," preoperational testing as used in this guide consists of those tests conducted prior to fuel loading, and intial startup testing refers to those tests performed after fuel loading.
*Lines indicate substantive changes from previous issue.


==B. DISCUSSION==
==B. DISCUSSION==
Criterion 1, "Quality Standards and Records," of                                    Reactor internals important to safety are designed to Appendix A, "General Design Criteria for Nuclear Power                            accommodate steady-state and transient vibratory loads Plants," to 10 CFR Part 50, "Licensing of Production                                for the service life of the reactor. This guide presents a and Utilization Facilities," requires that structures,                            comprehensive vibration assessment program for use in systems, and components important to safety be                                    verifying the structural integrity of the reactor internals designed, fabricated, erected, and tested to quality                              for flow-induced vibrations prior to commercial opera standards commensurate with the importance of the                                  tion. The overall program includes individual analytical, safety functions to be performed. Section 50.34, "Con                              measurement, and inspection programs. The term "com tents of Applications; Technical Information," of 10                              prehensive" appears in the title of the overall program to CFR Part 50 requires the applicant to determine and to                              emphasize that the individual programs should be used specify the margin of safety associated with normal                                cooperatively to verify structural integrity and to estab operation and anticipated operating transients.                                    lish the margin of safety. For example, the analytical program not only should be used to provide theoretical This guide presents a method acceptable to the NRC                            verification of structural integrity but also should be the
Reactor internals important to safety are designed to accommodate steady-state and transient vibratory loads for the service life of the reactor. This guide presents a comprehensive vibration assessment program for use in verifying the structural integrity of the reactor internals for 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 to emphasize that the individual programs should be used cooperatively to verify structural integrity and to estab lish the margin of safety. For example, the analytical program not only should be used to provide theoretical verification of structural integrity but also should be the basis for the choice of components and areas to be monitored in the measurement and inspection programs;  
*-'  staff for implementing the above requirements with                                  basis for the choice of components and areas to be respect to the internals of light-water-cooled reactors'                            monitored in the measurement and inspection programs;
the measurement program should be used to confirm the analysis, but the program (i.e., data acquisition, reduc tion, interpretation processes) should be sufficiently flexible to permit definition of any significant'vibratory modes that are present but were not included in the analysis; the inspection program should be considered and used as a powerful tool for quantitative (e.g., as an indicator of maximum total relative motion) as well as qualitative (e.g., establishment of boundary conditions by inspection evidence at component interfaces) verifica tion of both the analytical and measurement program results.
      during preoperational and initial startup testing. 2 Inser                          the measurement program should be used to confirm the vice inspections and inservice monitoring programs to                              analysis, but the program (i.e., data acquisition, reduc verify that the reactor internal components have not                                tion, interpretation processes) should be sufficiently been subjected to structural degradation as a result of                            flexible to permit definition of any significant'vibratory I vibration during normal reactor operation are not covered by this guide. The Advisory Committee on Reactor Safeguards has been consulted concerning this modes that are present but were not included in the analysis; the inspection program should be considered and used as a powerful tool for quantitative (e.g., as an guide and has concurred in the Regulatory Position.                                indicator of maximum total relative motion) as well as qualitative (e.g., establishment of boundary conditions lReactor internals, as used in this regulatory guide, comprise                    by inspection evidence at component interfaces) verifica core support structures and adjoining internal structures. Core                  tion of both the analytical and measurement program support and internal structures are defined in Article NG-1120                  results.


of Section III (Nuclear Power Plant Components) of the ASME
The original guidelines of Regulatory Guide 1.20
        Boiler and Pressure Vessel Code.
were refined in Revision 1 to incorporate items that would expedite review of the applicant's vibration assessment program by the NRC staff. Generally, this was accomplished by increased specificity in the guide lines for the vibration analysis, measurement, and inspection programs and by inclusion of guidelines for USNRC REGULATORY GUIDES
Comments should be sent to the Secretary of the Commission. U.S. Nuclear Regulatory Guides are issued to describe and make available to the public Regulatory Commissiooi.


The original guidelines of Regulatory Guide 1.20
Washington. D.C
      konsistent with Regulatory Guide 1.68, "Preoperational and                         were refined in Revision 1 to incorporate items that Initial Startup Test Programs for Water-Cooled Power                            would expedite review of the applicant's vibration Reactors," preoperational testing as used in this guide consists of those tests conducted prior to fuel loading, and intial startup              assessment program by the NRC staff. Generally, this testing refers to those tests performed after fuel loading.                      was accomplished by increased specificity in the guide lines for the vibration analysis, measurement, and
20566. Attention Docketing and methods acceptable to the NRC staff of implementing specific parts of the Service Section Commission's regulations, to delineate techniques used by the staff in evalu The guides are issued in the following ten broad divisions:
    *Lines indicate substantive changes from previous issue.
sting specific problems or postulated accidents, or to provide guidance to appli.


inspection programs and by inclusion of guidelines for USNRC REGULATORY GUIDES                                          Comments should be sent to the Secretary of the Commission. U.S. Nuclear Regulatory Guides are issued to describe and make available to the public            Regulatory Commissiooi.    Washington. D.C    20566. Attention Docketing and methods acceptable to the NRC staff of implementing specific parts of the            Service Section Commission's regulations, to delineate techniques used by the staff in evalu          The guides are issued in the following ten broad divisions:
cants. Regulatory Guides are not substitutes for regulations, and compliance
    sting specific problems or postulated accidents, or to provide guidance to appli.


cants. Regulatory Guides are not substitutes for regulations, and compliance          1. Power Reactors                       6. Products with them is not required. Methods and solutions different from those set out in     2. Research and Test Reactors           7. Transportation the guides will be acceptable if they provide a basis for the findings requisite to   3. Fuels and Materials Facilities       8. Occupa,.onal Health the issuance or continuance of a permit or license by the Commission.                4. Environmental and Siting            8. Antitrust Review Comments and suggestions for improvements in these guides are encouraged              5. Materials and Plant Protection      10. General at all times, and guides will be revised, as appropriate, to accommodate com ments and to reflect new information or experience. This guide was revised as a      Copies of published guides may be obtained by written request indicating the result of substantive comments received from the public and additional staff          divisions desired to the U.S. Nuclear Regulatory Commission. Washington. D.C.
===1. Power Reactors ===
6. Products with them is not required. Methods and solutions different from those set out in  
2. Research and Test Reactors  
7. Transportation the guides will be acceptable if they provide a basis for the findings requisite to  
3. Fuels and Materials Facilities  
8. Occupa,.onal Health the issuance or continuance of a permit or license by the Commission.


review.                                                                               20566. Attention: Director. Office of Standards Development.
4. Environmental and Siting
8. Antitrust Review Comments and suggestions for improvements in these guides are encouraged
5. Materials and Plant Protection
10. General at all times, and guides will be revised, as appropriate, to accommodate com ments and to reflect new information or experience. This guide was revised as a Copies of published guides may be obtained by written request indicating the result of substantive comments received from the public and additional staff divisions desired to the U.S. Nuclear Regulatory Commission. Washington. D.C.


scheduling significant phases of the comprehensive vibra          sequently modified in design (e.g., as in item 1.3 below)
review.
tion assessment program.                                          remains a Valid Prototype relative to its original design.


The original guidelines served as the basis for testing              .1.3 Conditional Prototype. A Valid Prototype many prototype and similar-to-prototype (referred to in          that later experiences adverse inservice vibration this guide as non-prototype) reactor internals. Operating        phenomena and subsequently has been modified in experience and the tendency for the design of sub                arrangement, design, size, or operating conditions is sequent reactor internals to differ somewhat from that            designated a Conditional Prototype. Upon satisfying of the initially designated prototypes, in some instances,        conditions described elsewhere in this guide, the Condi made the basic prototype and non-prototype classifica            tional Prototype serves as the reference design for tions difficult to apply, resulting in the need for              Non-Prototype, Category III and IV, reactor internals time-consuming case-by-case resolution of reactor inter          configurations.
20566. Attention: Director. Office of Standards Development.


nal classifications and corresponding vibration assess ment programs.                                                            1.4 Non-Prototype, Category I. A reactor inter nals configuration with substantially the same arrange Revision 1 expanded on the previous classifications          ment, design, size, and operating conditions as a and outlined an appropriate comprehensive vibration              specified Valid Prototype and for which nominal differ assessment program for each class. The classifications are        ences in arrangement, design, size, and operating condi defined in regulatory position C.I below. In general, the        tions have been shown by test or analysis to have no expanded classifications and corresponding programs              significant effect on the vibriatory response and allow for the use, under certain conditions, of prototype        excitation of those reactor internals important to safety.
Revision 2 May 1976


reactor internals that have experienced some adverse inservice vibration phenomena as limited prototypes and                  1.5 Non-Prototype, Category II. A reactor for the use, under certain conditions, of reactor internals      internals configuration with substantially the same size that are in some respects structurally dissimilar from the        and operating conditions as a specified Valid Prototype, designated prototype as limited non-prototypes. The              but with some component arrangement or design differ expanded classifications make the use of this guide              ences that are shown by test or analysis to have no compatible with design and operating experience. Revi            significant effect on the vibratory response and excita sion 2 retains the expanded classifications of Revision 1.        tion of those unmodified reactor internals important to Some changes in the corresponding vibration assessment           safety.
scheduling significant phases of the comprehensive vibra tion assessment program.


programs and in the reporting of results were made as a result of substantive public comments and additional                     1.6 Limited Valid Prototype. A Non-Prototype, staff review.                                                     Category II or III, reactor internals configuration that has successfully conrpleted the appropriate comprehen C
The original guidelines served as the basis for testing many prototype and similar-to-prototype (referred to in this guide as non-prototype) reactor internals. Operating experience and the tendency for the design of sub sequent reactor internals to differ somewhat from that of the initially designated prototypes, in some instances, made the basic prototype and non-prototype classifica tions difficult to apply, resulting in the need for time-consuming case-by-case resolution of reactor inter nal classifications and corresponding vibration assess ment programs.
 
Revision 1 expanded on the previous classifications and outlined an appropriate comprehensive vibration assessment program for each class. The classifications are defined in regulatory position C. I below. In general, the expanded classifications and corresponding programs allow for the use, under certain conditions, of prototype reactor internals that have experienced some adverse inservice vibration phenomena as limited prototypes and for the use, under certain conditions, of reactor internals that are in some respects structurally dissimilar from the designated prototype as limited non-prototypes. The expanded classifications make the use of this guide compatible with design and operating experience. Revi sion 2 retains the expanded classifications of Revision 1.
 
Some changes in the corresponding vibration assessment programs and in the reporting of results were made as a result of substantive public comments and additional staff review.
 
C


==Q. REGULATORY POSITION==
==Q. REGULATORY POSITION==
sive vibration assessment program and has itself experi enced no adverse inservice vibration phenomena. An The classifications provided in regulatory position C. I     operating Valid Prototype that has demonstrated should be used by the applicant to categorize the reactor       extended satisfactory inservice operation subsequent to a internals according to design, operating parameters, and         design modification may be considered a Limited Valid the operating experience of potential prototypes. The           Prototype relative to the modified reactor internals appropriate comprehensive vibration assessment program           configuration. A Conditional Prototype that has demon should then be established from the guidelines specified        strated extended satisfactory inservice operation may be for that classification in the succeeding selections of this    considered a Limited Valid Prototype.
The classifications provided in regulatory position C. I  
should be used by the applicant to categorize the reactor internals according to design, operating parameters, and the operating experience of potential prototypes. The appropriate comprehensive vibration assessment program should then be established from the guidelines specified for that classification in the succeeding selections of this guide. The comprehensive vibration assessment programs outlined in this guide are summarized in Figure 1.
 
1. Classification of Reactor Internals Relative to the Comprehensive Vibration Assessment Program
1.1 Prototype. A reactor internals configuration, that, because of its arrangement, design, size, or operat ing conditions, represents a first-of-a-kind or unique design for which no Valid Prototype exists.
 
1.2 Valid Prototype. A reactor internals config uration that has successfully completed a comprehensive vibration assessment program for Prototype reactor internals and has experienced no adverse inservice vibration 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 Prototype that later experiences adverse inservice vibration phenomena and subsequently has been modified in arrangement, design, size, or operating conditions is designated a Conditional Prototype. Upon satisfying conditions described elsewhere in this guide, the Condi tional Prototype serves as the reference design for Non-Prototype, Category III and IV, reactor internals configurations.
 
1.4 Non-Prototype, Category I. A reactor inter nals configuration with substantially the same arrange ment, design, size, and operating conditions as a specified 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 no significant effect on the vibriatory response and excitation of those reactor internals important to safety.
 
1.5 Non-Prototype, Category II.
 
A
reactor internals configuration with substantially the same size and operating conditions as a specified Valid Prototype, but with some component arrangement or design differ ences that are shown by test or analysis to have no significant effect on the vibratory response and excita tion of those unmodified reactor internals important to safety.
 
1.6 Limited Valid Prototype. A Non-Prototype, Category II or III, reactor internals configuration that has successfully conrpleted the appropriate comprehen sive vibration assessment program and has itself experi enced no adverse inservice vibration phenomena. An operating Valid Prototype that has demonstrated extended satisfactory inservice operation subsequent to a design modification may be considered a Limited Valid Prototype relative to the modified reactor internals configuration. A Conditional Prototype that has demon strated extended satisfactory inservice operation may be considered a Limited Valid Prototype.


guide. The comprehensive vibration assessment programs outlined in this guide are summarized in Figure 1.                      1.7 Non-Prototype, Category III. A reactor inter nals configuration with substantially the same arrange
1.7 Non-Prototype, Category III. A reactor inter nals configuration with substantially the same arrange ment, design, size, and operating conditions as a specified Conditional Prototype with insufficient operating history to justify it as a Limited Valid Prototype. Differences in arralpgement, design, size, and operating conditions should be shown by test or analysis to have no significant effect on the vibratory response and excitation of those reactor internals important to safety.
    1. Classification of Reactor Internals Relative to the        ment, design, size, and operating conditions as a Comprehensive Vibration Assessment Program                        specified Conditional Prototype with insufficient
      1.1 Prototype. A reactor internals configuration,          operating history to justify it as a Limited Valid that, because of its arrangement, design, size, or operat        Prototype. Differences in arralpgement, design, size, and ing conditions, represents a first-of-a-kind or unique            operating conditions should be shown by test or analysis design for which no Valid Prototype exists.                      to have no significant effect on the vibratory response and excitation of those reactor internals important to
        1.2 Valid Prototype. A reactor internals config          safety.


uration that has successfully completed a comprehensive vibration assessment program for Prototype reactor                      1.8 Non-Prototype, Category IV. A reactor inter internals and has experienced no adverse inservice                nals configuration with substantially the game arrange vibration phenomena. A Valid Prototype that is sub-              ment, design, size, and operating conditions as a
1.8 Non-Prototype, Category IV. A reactor inter nals configuration with substantially the game arrange ment, design, size, and operating conditions as a
                                                            1.20-2
1.20-2


Inservice problems resulting in component or operational modifications Valid Prototype modified
Inservice problems resulting in component or operational modifications NON-PROTOTYPE
                                                            \ Extended satisfactory /
CATEGORY I
                                                              \ rnservice operation /
Substantially Similar to Valid Prototype Analysis and Either Extensive Measurements
                                                          -~\~\             \     ,/
:or P-ull Inspection Valid Prototype modified  
  NON-PROTOTYPE                                                                        NON-PROTOTYPE
\\ Extended satisfactory /  
      CATEGORY I                                                                         CATEGORY I II
\\ rnservice operation /  
  Substantially Similar                                                                Substantially Similar to to Valid Prototype                                                                  Conditional Prototype Analysis and Either                                                                  Analysis, Limited Extensive Measurements                                                                Measurements, and
-~\\~\\  
    :or P-ull Inspection Full Inspection NON-PROTOTYPE
\\
                                                                  CATEGORY IV
,/
                                                            Substantially Similar to Limited Valid Prototvoe IZZJ             Reactor internals configuration for which comprehensive vibration assessment program is defined.
NON-PROTOTYPE  
CATEGORY I I I
Substantially Similar to Conditional Prototype Analysis, Limited Measurements, and Full Inspection NON-PROTOTYPE  
CATEGORY IV  
Substantially Similar to Limited Valid Prototvoe IZZJ  
L I
cm Reactor internals configuration for which comprehensive vibration assessment program is defined.


L I              Summary of comprehensive vibration assessment programs.
Summary of comprehensive vibration assessment programs.


cm                Reactor internals reference design which, together with its test and operating experience, provides the basis for a specific comprehensive vibration assessment program.
Reactor internals reference design which, together with its test and operating experience, provides the basis for a specific comprehensive vibration assessment program.


Indicates alternative paths FIGURE 1 - SUMMARY OF COMPREHENSIVE VIBRATION ASSESSMENT PROGRAMS
Indicates alternative paths FIGURE 1 - SUMMARY OF COMPREHENSIVE VIBRATION ASSESSMENT PROGRAMS
                                                    1.20-3
1.20-3
 
specified Limited Valid Prototype, where nominal differ ences in arrangement, design, size, and operating condi tions have been shown by test or analysis to have no significant effect on the vibratory response and excita tion of those reactor internals important to safety.


specified Limited Valid Prototype, where nominal differ      ciently simulated by the test conditions should be ences in arrangement, design, size, and operating condi      identified.)
Associated with the Prototype and the Category I, II,  
tions have been shown by test or analysis to have no significant effect on the vibratory response and excita                6. The anticipated structural or hydraulic tion of those reactor internals important to safety.        vibratory response (defined in terms of frequency, amplitude, and modal contributions) that is appropriate Associated with the Prototype and the Category I, II,   to each of the sensor locations for steady-state and III, and IV Non-Prototype classifications are the           anticipated transient preoperational and startup test comprehensive vibration assessment programs delineated      conditions.
III, and IV Non-Prototype classifications are the comprehensive vibration assessment programs delineated in regulatory positions C.2 and C.3 and summarized in Figure 1. The foregoing classifications are defined relative to the three prototype reference design classifi cations (i.e., Valid Prototype, Conditional Prototype, Limited Valid Prototype) upon whose design, test, and operating experience the individual comprehensive vibration assessment programs are based.


in regulatory positions C.2 and C.3 and summarized in Figure 1. The foregoing classifications are defined                    7. The test acceptance criteria with permissible relative to the three prototype reference design classifi    deviations and the basis for the criteria. (The criteria cations (i.e., Valid Prototype, Conditional Prototype,      should be established in terms of maximum allowable Limited Valid Prototype) upon whose design, test, and       response levels in the structure and presented in terms of operating experience the individual comprehensive            maximum allowable response levels at sensor locations.)
2. Comprehensive Vibration Assessment Program for Prototype Reactor Internals The comprehensive vibration assessment program should be implemented in conjunction with preopera tional and initial startup testing. It should consist of a vibration analysis, a vibration measurement program, an inspection program, and a correlation of their results.
vibration assessment programs are based.


2. Comprehensive Vibration Assessment Program for                2.2 Vibration Measurement Program Prototype Reactor Internals A vibration measurement program should be The comprehensive vibration assessment program        developed and implemented to verify the structural should be implemented in conjunction with preopera            integrity of the reactor internals, to determine the tional and initial startup testing. It should consist of a    margin of safety associated with steady-state and antici vibration analysis, a vibration measurement program, an      pated transient conditions for normal operation, and to inspection program, and a correlation of their results.      confirm the results of the vibration analysis. The vibration measurement program should include a
2.1 Vibration Analysis Program The vibration analysis should be performed for those steady-state and anticipated transient conditions that correspond to preoperational and initial startup test and normal operating conditions. The vibration analysis submittal should include a summary of:  
      2.1 Vibration Analysis Program                         description of:
1. The theoretical structural and hydraulic models and analytical formulations or scaling laws and scale models used in the analysis.
          The vibration analysis should be performed for those steady-state and anticipated transient conditions                 1. The data acquisition and reduction system, that correspond to preoperational and initial startup test   including:
and normal operating conditions. The vibration analysis submittal should include a summary of:                                     a. Transducer types and their specifications, including useful frequency and amplitude ranges.


1. The theoretical structural and hydraulic models and analytical formulations or scaling laws and                      b. Transducer positions, which should be sufficient to monitor significant lateral, vertical, and scale models used in the analysis.
2. The structural and hydraulic system natural frequencies and associated mode shapes which may be excited during steady-state and anticipated transient operation.


torsional structural motions of major reactor internal
3. The estimated random and deterministic forcing functions, including any very-low-frequency components, for steady-state and anticipated transient operation.
          2. The structural and hydraulic system natural      components in shell, beam, and rigid body modes of frequencies and associated mode shapes which may be          vibration, as well as significant hydraulic responses and excited during steady-state and anticipated transient         those parameters that can be used to confirm the input forcing function.


4. The calculated structural and hydraulic responses for steady-state and anticipated transient operation. (The random, deterministic, overall integrated maximum response, any very-low-frequency components of response, and the level of cumulative fatigue damage should be identified.)
5. A comparison of the calculated structural and hydraulic responses for preoperational and initial startup testing with those for normal operation. (Normal operating conditions that are not accurately or suffi- ciently simulated by the test conditions should be identified.)
6. The anticipated structural or hydraulic vibratory response (defined in terms of frequency, amplitude, and modal contributions) that is appropriate to each of the sensor locations for steady-state and anticipated transient preoperational and startup test conditions.
7. The test acceptance criteria with permissible deviations and the basis for the criteria. (The criteria should be established in terms of maximum allowable response levels in the structure and presented in terms of maximum allowable response levels at sensor locations.)
2.2 Vibration Measurement Program A vibration measurement program should be developed and implemented to verify the structural integrity of the reactor internals, to determine the margin of safety associated with steady-state and antici pated transient conditions for normal operation, and to confirm the results of the vibration analysis. The vibration measurement program should include a description 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 be sufficient to monitor significant lateral, vertical, and torsional structural motions of major reactor internal components in shell, beam, and rigid body modes of vibration, as well as significant hydraulic responses and those parameters that can be used to confirm the input forcing function.
c. Precautions being taken to ensure acquisi tion of quality data (e.g., optimization of signal-to-noise ratio, relationship of recording times to data reduction requirements, choice of instrumentation system). 
d. On-line data evaluation system to provide immediate verification of general quality and level of data.
e. Procedures for determining frequency, modal content, and maximum values of response.
2. Test operating conditions, including:
operation.
operation.


3. The estimated random and deterministic                        c. Precautions being taken to ensure acquisi forcing functions, including any very-low-frequency          tion of quality data (e.g., optimization of signal-to-noise components, for steady-state and anticipated transient       ratio, relationship of recording times to data reduction requirements, choice of instrumentation system).
a. All steady-state and transient modes of
operation.
1.20-4
 
b. The planned duration of all testing in normal operating modes to ensure that each critical component will have been subjected to at least 106 cycles of vibration (i.e., computed at the lowest fre quency for which the component has a significant structural response) prior to the final inspection of the reactor internals. The duration of testing for non prototype reactor internals should be no less than that for the applicable reference reactor internals (i.e., Valid, Conditional, or Limited Valid Prototype). 
c. Disposition of fuel assemblies. (Testing should be performed with the reactor internals impor tant to safety and the fuel assemblies (or dummy assemblies which provide equivalent dynamic mass and flow characteristics) in position. The test may be conducted without real or dummy fuel assemblies if it can be shown by analytical or experimental means that such conditions will yield conservative results.)
2.3 Inspection Program The inspection program should provide for inspections of the reactor internals prior to and follow ing operation at those steady-state and transient modes consistent with the test conditions for regulatory position C.2.2.2. The reactor internals should be removed from the reactor vessel for these inspections. If removal is not feasible, the inspections should be performed by means of examination equipment appro priate for in situ inspection. The inspection program should include:
1. A tabulation of all reactor internal compo nents and local areas to be inspected, including:
a. All major load-bearing elements of the reactor internals relied upon to retain the core support structure in position.
 
b. The lateral, vertical, and torsional restraints provided within the vessel.
 
c. Those locking and bolting components whose failure could adversely affect the structural integrity of the reactor internals.
 
d. Those surfaces that are known to be or may become contact surfaces during operation.
 
e. Those critical locations on the reactor internal components as identified by the vibration analysis.
 
f. The interior of the reactor vessel for evidence of loose parts or foreign material.
 
2. A tabulation of specific inspection areas that can be used to verify segments of the vibration analysis and measurement program.
 
3. A description of the inspection procedure, including the method of examination (e.g., visual and nondestructive surface examinations), method of docu mentation, access provisions on the reactor internals, and specialized equipment to be employed during the inspections to detect and quantify evidence of the effects of vibration.
 
2.4 Documentation of Results The results of the vibration analysis, measure ment, and inspection programs should be reviewed and correlated to determine the extent to which the test acceptance criteria are satisfied. A summary of the results should be submitted to the Commission in the form of preliminary and final reports.
 
1. The preliminary report should summarize an evaluation of the raw and, as necessary, limited proc essed data and the results of the inspection program with respect to the test acceptance criteria. Anomalous data that could bear on the structural integrity of the reactor internals should be identified, as should the method to be used for evaluating such data.
 
2. If the results of the comprehensive vibration assessment program are acceptable, the final report should include:
a. A description of any deviations from the specified measurement and inspection programs, including instrumentation reading and inspection anomalies, instrumentation malfunctions, and deviations from the specified operating conditions, b. A comparison between the measured and analytically determined modes of structural and hydraulic response (including those parameters from which the input forcing function is determined) for the purpose of establishing the validity of the analytical technique, c. A determination of the margin of safety associated with normal steady-state and anticipated transient operation, d. An evaluation of measurements that exceeded acceptable limits not specified as test acceptance criteria or of observations that were unantici pated and the disposition of such deviations.
 
3. If (1) inspection of the reactor internals reveals defects, evidence of unacceptable motion, excessive or undue wear, (2) the results from the
1.20-5
 
measurement program fail to satisfy the specified test acceptance criteria, or (3) the results from the analysis, measurement, and inspection programs are inconsistent, the final report should also include an evaluation and description of the modifications or actions planned in order to justify the structural adequacy of the reactor internals.
 
4. The collection, storage, and maintenance of all records relevant to the analysis, measurement, and inspection phases of the comprehensive vibration assess ment program should be consistent with Regulatory Guide 1.88, "Collection, Storage, and Maintenance of Nuclear Power Plant Quality Assurance Records," which describes a method acceptable to the NRC staff for complying with Criterion XVII, "Quality Assurance Records," of Appendix B, "Quality Assurance Criteria for Nuclear Power Plants and Fuel Reprocessing Plants,"
to 10 CFRPart 50.
 
2.5 Schedule A schedule should be established and submitted to the Commission during the construction permit review. The schedule should provide that:
1. The reactor internals design will be classified in the Preliminary Safety Analysis Report (PSAR) as a prototype or a specific category of non-prototype. The classification may be revised in the Final Safety Analysis Report if schedule changes with respect to the previ ously designated reference reactor make such reclassifi cation appropriate. (If the internals are classified as non-prototype, the applicant should identify the appli cable prototype reactor internals in the PSAR. Experi mental or analytical justification for the non-prototype classification should be presented during the construc tion permit review.)
2. A commitment will be established during the construction permit review regarding the scope of the comprehensive vibration assessment program.


4. The calculated structural and hydraulic                        d. On-line data evaluation system to provide responses for steady-state and anticipated transient          immediate verification of general quality and level of operation. (The random, deterministic, overall integrated    data.
3. A description of the vibration measurement and inspection phases of the comprehensive vibration assessment program will be submitted to the Com mission in sufficient time to permit utilization of Commission recommendations. (A 90-day comment and review period by the staff should be assumed by the applicant for scheduling purposes.)
4. A summary of the vibration analysis pro gram will be submitted to the Commission a minimum of 60 days prior to submittal of the description of the vibration measurement and inspection programs. (As an alternative, the information in this report may be submitted to the Commission in conjunction with the report specified in regulatory position C.2.5.3. In this case, a 120-day comment and review period for the composite report should be assumed by the applicant for scheduling purposes.)
5. The preliminary and final reports, which together summarize the results of the vibration analysis, measurement, and inspection programs, will be pre sented to the Commission within 60 and 180 days, respectively, of the completion of vibration testing.


maximum response, any very-low-frequency components of response, and the level of cumulative fatigue damage                    e. Procedures for determining frequency, should be identified.)                                        modal content, and maximum values of response.
3. Comprehensive Vibration Assessment Programs for Non-Prototype Reactor Internals Non-prototype reactor internals important to safety should be subjected during the preoperational and initial startup test program to all significant flow modes associated with normal steady-state and anticipated transient operation under the same test conditions imposed on the applicable prototype. Evaluation of the effects of such operation on the structural integrity of the non-prototype reactor internals should be based on the results of a comprehensive vibration assessment program developed for the specific non-prototype classi fication (i.e., Category I, II, III, or IV). The comprehen sive vibration assessment programs for non-prototype reactor internals are outlined below. These programs should be scheduled and documented in accordance with the guidelines for the program delineated in regulatory positions C.2.4 and C.2.5 for Prototype reactor inter nals.


5. A comparison of the calculated structural                  2. Test operating conditions, including:
3.1 Non-Prototype, Category I
and hydraulic responses for preoperational and initial startup testing with those for normal operation. (Normal                  a. All steady-state and transient modes of operating conditions that are not accurately or suffi-       operation.
3.1.1 Vibration Analysis Program The Valid Prototype should be specified and sufficient evidence should be provided to support the classification Non-Prototype, Category I.


1.20-4
The vibration analysis for the Valid Proto type, which includes a summary of the anticipated structural and hydraulic response and test acceptance criteria, should be modified to account for the nominal differences that may exist between the Non-Prototype, Category I, and Valid Prototype reactor internals.


b. The planned duration of all testing in                    2. A tabulation of specific inspection areas that normal operating modes to ensure that each critical                can be used to verify segments of the vibration analysis component will have been subjected to at least 106                and measurement program.
3.1.2 Vibration Measurement Program The vibration measurement program may be omitted if the inspection program is implemented.


cycles of vibration (i.e., computed at the lowest fre quency for which the component has a significant                          3. A description of the inspection procedure, structural response) prior to the final inspection of the       including the method of examination (e.g., visual and reactor internals. The duration of testing for non              nondestructive surface examinations), method of docu prototype reactor internals should be no less than that          mentation, access provisions on the reactor internals, for the applicable reference reactor internals (i.e., Valid,     and specialized equipment to be employed during the Conditional, or Limited Valid Prototype).                         inspections to detect and quantify evidence of the effects of vibration.
If a measurement program is implemented in lieu of an inspection program, sufficient and appropriate instrumentation should be incorporated to verify that the vibratory response of the Non-Prototype, Category I,  
reactor internals is consistent with the results of the vibration analysis, test acceptance criteria, and the vibratory response observed in the Valid Prototype. The vibration measurement program should include a description of the data acquisition and reduction
1.20-6


c. Disposition of fuel assemblies. (Testing should be performed with the reactor internals impor                    2.4 Documentation of Results tant to safety and the fuel assemblies (or dummy assemblies which provide equivalent dynamic mass and                        The results of the vibration analysis, measure flow characteristics) in position. The test may be              ment, and inspection programs should be reviewed and conducted without real or dummy fuel assemblies if it            correlated to determine the extent to which the test can be shown by analytical or experimental means that            acceptance criteria are satisfied. A summary of the such conditions will yield conservative results.)                results should be submitted to the Commission in the form of preliminary and final reports.
systems and test operating conditions consistent with the general guidelines for the vibration measurement program delineated in regulatory position C.2.2 for Prototype reactor internals.


1. The preliminary report should summarize an
3.1.3 Inspection Program If an inspection program is implemented in lieu of a vibration measurement program, the guidelines for the inspection program delineated in regulatory position C.2.3 for Prototype reactor internals should be followed.
      2.3 Inspection Program evaluation of the raw and, as necessary, limited proc essed data and the results of the inspection program with The inspection program should provide for respect to the test acceptance criteria. Anomalous data inspections of the reactor internals prior to and follow that could bear on the structural integrity of the reactor ing operation at those steady-state and transient modes consistent with the test conditions for regulatory               internals should be identified, as should the method to position C.2.2.2. The reactor internals should be                 be used for evaluating such data.


removed from the reactor vessel for these inspections. If removal is not feasible, the inspections should be                          2. If the results of the comprehensive vibration performed by means of examination equipment appro                assessment program are acceptable, the final report priate for in situ inspection. The inspection program             should include:
The inspection program may be omitted if the vibration measurement program is implemented.
should include:
                                                                                a. A description of any deviations from the specified measurement and inspection programs,
          1. A tabulation of all reactor internal compo          including instrumentation reading and inspection nents and local areas to be inspected, including:                anomalies, instrumentation malfunctions, and deviations from the specified operating conditions, a. All major load-bearing elements of the reactor internals relied upon to retain the core support                      b. A comparison between the measured and structure in position.                                            analytically determined modes of structural and hydraulic response (including those parameters from b. The lateral, vertical,      and    torsional      which the input forcing function is determined) for the restraints provided within the vessel.                            purpose of establishing the validity of the analytical technique, c. Those locking and bolting components whose failure could adversely affect the structural                            c. A determination of the margin of safety integrity of the reactor internals.                              associated with normal steady-state and anticipated transient operation, d. Those surfaces that are known to be or may become contact surfaces during operation.                                  d. An evaluation of measurements that exceeded acceptable limits not specified as test e. Those critical locations on the reactor          acceptance criteria or of observations that were unantici internal components as identified by the vibration              pated and the disposition of such deviations.


analysis.
However, if significant discrepancies exist between anticipated and measured responses for specific compo nents, those components should be removed from the reactor vessel and a visual examination performed.


3. If (1) inspection of the reactor internals f. The interior of the reactor vessel for           reveals defects, evidence of unacceptable motion, evidence of loose parts or foreign material.                     excessive or undue wear, (2) the results from the
Components for which removal is not feasible should be examined in situ by means of appropriate inspection equipment. In any case, the interior of the reactor vessel should be visually checked for loose parts and foreign material.
                                                            1.20-5


measurement program fail to satisfy the specified test            composite report should be assumed by the applicant for acceptance criteria, or (3) the results from the analysis,        scheduling purposes.)
3.2 Non-Prototype, Category II
measurement, and inspection programs are inconsistent, the final report should also include an evaluation and                      5. The preliminary and final reports, which description of the modifications or actions planned in            together summarize the results of the vibration analysis, order to justify the structural adequacy of the reactor          measurement, and inspection programs, will be pre internals.                                                        sented to the Commission within 60 and 180 days, respectively, of the completion of vibration testing.
3.2.1 Vibration Analysis Program and The Valid Prototype should be specified, and sufficient evidence should be provided to support the classification Non-Prototype, Category II, which requires demonstrating that the structural differences that exist between the Non-Prototype, Category II,  
and Valid Prototype reactor internals have no significant effect on the vibratory response and excitation of those unmodified Non-Prototype, Category II, components.


4. The collection, storage, and maintenance of all records relevant to the analysis, measurement, and               3. Comprehensive Vibration Assessment Programs inspection phases of the comprehensive vibration assess          for Non-Prototype Reactor Internals ment program should be consistent with Regulatory Guide 1.88, "Collection, Storage, and Maintenance of                        Non-prototype reactor internals important to Nuclear Power Plant Quality Assurance Records," which            safety should be subjected during the preoperational and describes a method acceptable to the NRC staff for               initial startup test program to all significant flow modes complying with Criterion XVII, "Quality Assurance                associated with normal steady-state and anticipated Records," of Appendix B, "Quality Assurance Criteria              transient operation under the same test conditions for Nuclear Power Plants and Fuel Reprocessing Plants,"          imposed on the applicable prototype. Evaluation of the to 10 CFRPart 50.                                                effects of such operation on the structural integrity of the non-prototype reactor internals should be based on
The vibration analysis for the Valid Proto type, which includes a summary of the anticipated structural and hydraulic response and test acceptance criteria, should be modified to account for the structural differences that exist between the Valid Prototype and Non-Prototype, Category 1I, reactor internals.
      2.5 Schedule                                              the results of a comprehensive vibration assessment program developed for the specific non-prototype classi A schedule should be established and submitted        fication (i.e., Category I, II, III, or IV). The comprehen to the Commission during the construction permit                  sive vibration assessment programs for non-prototype review. The schedule should provide that:                        reactor internals are outlined below. These programs should be scheduled and documented in accordance with
          1. The reactor internals design will be classified    the guidelines for the program delineated in regulatory in the Preliminary Safety Analysis Report (PSAR) as a            positions C.2.4 and C.2.5 for Prototype reactor inter prototype or a specific category of non-prototype. The            nals.


classification may be revised in the Final Safety Analysis Report if schedule changes with respect to the previ                      3.1 Non-Prototype, Category I
Test acceptance criteria should specifically be established for those Non-Prototype, Category II,
ously designated reference reactor make such reclassifi cation appropriate. (If the internals are classified as                      3.1.1 Vibration Analysis Program non-prototype, the applicant should identify the appli cable prototype reactor internals in the PSAR. Experi                          The Valid Prototype should be specified and mental or analytical justification for the non-prototype          sufficient evidence should be provided to support the classification should be presented during the construc            classification Non-Prototype, Category I.
reactor internal components with structural differences relative to the Valid Prototype.


tion permit review.)
3.2.2 Vibration Measurement Program A vibration measurement program should be implemented on the Non-Prototype, Category II, reactor internals during preoperational and initial startup testing.
                                                                                The vibration analysis for the Valid Proto
          2. A commitment will be established during            type, which includes a summary of the anticipated the construction permit review regarding the scope of            structural and hydraulic response and test acceptance the comprehensive vibration assessment program.                  criteria, should be modified to account for the nominal differences that may exist between the Non-Prototype,
          3. A description of the vibration measurement          Category I, and Valid Prototype reactor internals.


and inspection phases of the comprehensive vibration assessment program will be submitted to the Com                              3.1.2 Vibration Measurement Program mission in sufficient time to permit utilization of Commission recommendations. (A 90-day comment and                              The vibration measurement program may be review period by the staff should be assumed by the               omitted if the inspection program is implemented.
The vibration measurement program should include a description of the data acquisition and reduction systems and test operating conditions con sistent with the general guidelines for the vibration measurement program delineated in regulatory position C.2.2 for Prototype reactor internals.


applicant for scheduling purposes.)
Sufficient and appropriate instrumentation should be used to define the vibratory response (i.e.,  
                                                                                If a measurement program is implemented in
frequency, amplitude, modal content) of those reactor internal components important to safety that have been modified relative to the Valid Prototype for the purpose of demonstrating that the test acceptance criteria are satisfied and establishing the margin of safety.
          4. A summary of the vibration analysis pro              lieu of an inspection program, sufficient and appropriate gram will be submitted to the Commission a minimum                instrumentation should be incorporated to verify that of 60 days prior to submittal of the description of the          the vibratory response of the Non-Prototype, Category I,
vibration measurement and inspection programs. (As an            reactor internals is consistent with the results of the alternative, the information in this report may be                vibration analysis, test acceptance criteria, and the submitted to the Commission in conjunction with the              vibratory response observed in the Valid Prototype. The report specified in regulatory position C.2.5.3. In this          vibration measurement program should include a case, a 120-day comment and review period for the                 description of the data acquisition and reduction
                                                            1.20-6


systems and test operating conditions consistent with          reduction systems and test operating conditions con the general guidelines for the vibration measurement          sistent with the general guidelines for the vibration program delineated in regulatory position C.2.2 for            measurement program delineated in regulatory position Prototype reactor internals.                                  C.2.2 for Prototype reactor internals.
Sufficient and appropriate instrumentation should be used to monitor those reactor internal components important to safety that have not been modified relative to the Valid Prototype to confirm that the vibratory response of such components complies with the guidelines for Non-Prototype, Category II,
reactor internals and is consistent with the results obtained for similar components during the measure ment program on the Valid Prototype.


3.1.3 Inspection Program                                         Sufficient and appropriate instrumentation should be used to define the vibratory response (i.e.,
3.2.3 Inspection Program An inspection program that follows the guidelines for the inspection program delineated in regulatory position C.2.3 for Prototype reactor internals should be implemented.
              If an inspection program is implemented in      frequency, amplitude, modal content) of those reactor lieu of a vibration measurement program, the guidelines       internal components important to safety that have been for the inspection program delineated in regulatory           modified relative to the Valid Prototype for the purpose position C.2.3 for Prototype reactor internals should be       of demonstrating that the test acceptance criteria are followed.                                                      satisfied and establishing the margin of safety.


The inspection program may be omitted if                      Sufficient and appropriate instrumentation the vibration measurement program is implemented.              should be used to monitor those reactor internal However, if significant discrepancies exist between            components important to safety that have not been anticipated and measured responses for specific compo        modified relative to the Valid Prototype to confirm that nents, those components should be removed from the            the vibratory response of such components complies reactor vessel and a visual examination performed.            with the guidelines for Non-Prototype, Category II,
3.3 Non-Prototype, Category HI
Components for which removal is not feasible should be        reactor internals and is consistent with the results examined in situ by means of appropriate inspection            obtained for similar components during the measure equipment. In any case, the interior of the reactor vessel    ment program on the Valid Prototype.
3.3.1 Vibration Analysis Program The Conditional Prototype should be specified, and sufficient analytical or experimental evidence should be provided to support the classification Non-Prototype, Category III, as well as to demonstrate the applicability of data from the vibration measurement program on the Prototype to the Conditional Prototype.


should be visually checked for loose parts and foreign material.                                                                3.2.3 Inspection Program
It should be demonstrated that:
        3.2 Non-Prototype, Category II                                      An inspection program that follows the guidelines for the inspection program delineated in
1. The Conditional Prototype is sub stantially similar in arrangement, design, size, and operating conditions to the Non-Prototype, Category III,
          3.2.1 Vibration Analysis Program                    regulatory position C.2.3 for Prototype reactor internals should be implemented.
reactor internals.


and           The Valid Prototype should be specified, and sufficient evidence should be provided to support the classification Non-Prototype, Category II, which                  3.3 Non-Prototype, Category HI
2. Response modes attributable to the inservice vibration problems and ensuing component or operational modifications do not significantly affect the applicability of the results of the vibration measurement program on the Prototype to the Conditional Prototype, or response modes attributable to the inservice vibration problems and ensuing component or operational modifi cations do affect the applicability of the results of the vibration measurement program on the Prototype to the Conditional Prototype, but the effects are limited to structural components and response modes that permit
requires demonstrating that the structural differences that exist between the Non-Prototype, Category II,                        3.3.1 Vibration Analysis Program and Valid Prototype reactor internals have no significant effect on the vibratory response and excitation of those                    The Conditional Prototype should be unmodified Non-Prototype, Category II, components.            specified, and sufficient analytical or experimental evidence should be provided to support the classification The vibration analysis for the Valid Proto      Non-Prototype, Category III, as well as to demonstrate type, which includes a summary of the anticipated              the applicability of data from the vibration measurement structural and hydraulic response and test acceptance          program on the Prototype to the Conditional Prototype.
1.20-7


criteria, should be modified to account for the structural    It should be demonstrated that:
clear separation of these effects from other results of the vibration measurement program.
differences that exist between the Valid Prototype and Non-Prototype, Category 1I, reactor internals.                                  1. The Conditional Prototype is sub stantially similar in arrangement, design, size, and Test acceptance criteria should specifically    operating conditions to the Non-Prototype, Category III,
be established for those Non-Prototype, Category II,          reactor internals.


reactor internal components with structural differences relative to the Valid Prototype.                                                2. Response modes attributable to the inservice vibration problems and ensuing component or
Details concerning the adverse vibration experience of the Conditional Prototype should be provided, as should experimental or analytical informa tion which demonstrates that the vibration problems associated with the Conditional Prototype have been corrected for both it and the applicable Non-Prototype, Category III, reactor internals.
          3.2.2 Vibration Measurement Program                operational modifications do not significantly affect the applicability of the results of the vibration measurement A vibration measurement program should be       program on the Prototype to the Conditional Prototype, implemented on the Non-Prototype, Category II, reactor         or response modes attributable to the inservice vibration internals during preoperational and initial startup            problems and ensuing component or operational modifi testing.                                                      cations do affect the applicability of the results of the vibration measurement program on the Prototype to the The vibration measurement program should        Conditional Prototype, but the effects are limited to include a description of the data acquisition and              structural components and response modes that permit
                                                        1.20-7


clear separation of these effects from other results of the     regulatory position C.2.3 for Prototype reactor internals vibration measurement program.                                  should be implemented.
The vibration analysis on the Prototype to the Conditional Prototype, which includes a summary of the anticipated structural and hydraulic response and test acceptance criteria for the measurement program on the Prototype, should be modified to account for the component or operational modifications applicable to the Conditional Prototype and Non-Prototype, Category III, reactor internals.


Details concerning the adverse vibration                  3.4 Non-Prototype, Category IV
Test acceptance criteria, with permissible deviations, should be specified for reactor internal components important to safety. Each component should be categorized according to whether the results from the vibration measurement program on the Proto type to the Conditional Prototype are applicable.
experience of the Conditional Prototype should be provided, as should experimental or analytical informa                    3.4.1 Vibration Analysis Program tion which demonstrates that the vibration problems associated with the Conditional Prototype have been                            The Limited Valid Prototype should be corrected for both it and the applicable Non-Prototype,          specified, and sufficient evidence should be provided to Category III, reactor internals.                                support the classification Non-Prototype, Category IV.


The vibration analysis on the Prototype to the Conditional Prototype, which includes a summary of                    3.4.2 Vibration Measurement Program the anticipated structural and hydraulic response and test acceptance criteria for the measurement program on                        A vibration measurement program may be the Prototype, should be modified to account for the            omitted if the inspection program is implemented.
3.3.2 Vibration Measurement Program A vibration measurement program should be implemented on the Non-Prototype, Category III,
reactor internals during preoperational and initial startup testing.


component or operational modifications applicable to the Conditional Prototype and Non-Prototype, Category                          If a measurement program is implemented in III, reactor internals.                                          lieu of an inspection program, sufficient and appropriate instrumentation should be incorporated to verify that the vibratory response of the Non-Prototype, Category Test acceptance criteria, with permissible deviations, should be specified for reactor internal            IV, reactor internals is consistent with the results of the components important to safety. Each component                  vibration analysis, test acceptance criteria, and the should be categorized according to whether the results          vibratory response for the referenced limited Valid from the vibration measurement program on the Proto              Prototype.
Sufficient and appropriate instrumentation should be used to define the vibratory response of those reactor components important to safety which, because of structural or operational modifications relative to the original design of the Conditional Prototype, are expected to have response characteristics substantially different from those measured for that component during the vibration measurement program on the Prototype to the Conditional Prototype.


type to the Conditional Prototype are applicable.
All other components should be monitored with sufficient and appropriate instrumentation to con firm that the measured response for each component is substantially similar to that obtained during the vibra tion measurement program on the Prototype to the Conditional Prototype.


The vibration measurement program should
The vibration measurement program should satisfy the general guidelines for a Prototype measure ment program as delineated in regulatory position C.2.2.
          3.3.2 Vibration Measurement Program                    be consistent with the guidelines delineated in regulatory position C.3.1.2 for the measurement program for A vibration measurement program should be          Non-Prototype, Category I, reactor internals.


implemented on the Non-Prototype, Category III,
3.3.3 Inspection Program An inspection program that satisfies the guidelines for the inspection program delineated in regulatory position C.2.3 for Prototype reactor internals should be implemented.
reactor internals during preoperational and initial startup                3.4.3 Inspection Program testing.


If an inspection program is implemented in lieu of a vibration measurement program, the guidelines Sufficient and appropriate instrumentation for the    inspection program delineated in regulatory should be used to define the vibratory response of those position  C.3.1.3 for Non-Prototype, Category I, reactor reactor components important to safety which, because of structural or operational modifications relative to the        internals should be followed.
3.4 Non-Prototype, Category IV
3.4.1 Vibration Analysis Program The Limited Valid Prototype should be specified, and sufficient evidence should be provided to support the classification Non-Prototype, Category IV.


original design of the Conditional Prototype, are expected to have response characteristics substantially different from those measured for that component during the vibration measurement program on the                                    
3.4.2 Vibration Measurement Program A vibration measurement program may be omitted if the inspection program is implemented.


==D. IMPLEMENTATION==
If a measurement program is implemented in lieu of an inspection program, sufficient and appropriate instrumentation should be incorporated to verify that the vibratory response of the Non-Prototype, Category IV, reactor internals is consistent with the results of the vibration analysis, test acceptance criteria, and the vibratory response for the referenced limited Valid Prototype.
Prototype to the Conditional Prototype.


The purpose of this section is to provide guidance to All other components should be monitored          applicants and licensees regarding the NRC staffs plans with sufficient and appropriate instrumentation to con          for utilizing this regulatory guide.
The vibration measurement program should be consistent with the guidelines delineated in regulatory position C.3.1.2 for the measurement program for Non-Prototype, Category I, reactor internals.


firm that the measured response for each component is substantially similar to that obtained during the vibra              Except in those cases in which the applicant proposes tion measurement program on the Prototype to the                 an acceptable alternative method for complying with Conditional Prototype.
3.4.3 Inspection Program If an inspection program is implemented in lieu of a vibration measurement program, the guidelines for the inspection program delineated in regulatory position C.3.1.3 for Non-Prototype, Category I, reactor internals should be followed.


specified portions of the Commission's regulations, the method described herein will be used in the evaluation The vibration measurement program should          of submittals for operating license or construction satisfy the general guidelines for a Prototype measure          permit applications docketed after June 22, 1976.
==D. IMPLEMENTATION==
The purpose of this section is to provide guidance to applicants and licensees regarding the NRC staffs plans for utilizing this regulatory guide.


ment program as delineated in regulatory position C.2.2.
Except in those cases in which the applicant proposes an acceptable alternative method for complying with specified portions of the Commission's regulations, the method described herein will be used in the evaluation of submittals for operating license or construction permit applications docketed after June 22, 1976.


3.3.3 Inspection Program                                  If an applicant wishes to use this regulatory guide in developing submittals for applications docketed on or An inspection program that satisfies the          before June 22, 1976, the pertinent portions of the guidelines for the inspection program delineated in              application will be evaluated on the basis of this guide.
If an applicant wishes to use this regulatory guide in developing submittals for applications docketed on or before June 22, 1976, the pertinent portions of the application will be evaluated on the basis of this guide.


1.20-8
1.20-8


SPROTOTYPE
SPROTOTYPE  
                                  [Unique or first of a kind Analysis, Extensive Measurement, and Full Inspection I
[Unique or first of a kind Analysis, Extensive Measurement, and Full Inspection I
                                                            JInservice  problems resulting in component     or Vlid :Proto"         prtoa         oiiain             Conditional
tNON
                                                                                        //
PROTOTYPEyp CATEGORY I
        CATEGORY I
Substantially Similar
                                        NON-PROTOTYPE             \INON-PROTOTYPE
,to Valid-Prototype Analysis and Either Extensive Measurements or Full Inspection GIlD
                                          CATEGORY II                                           CTGR
EZZJ
                                    Similar to ValidPrototype                                   CTG           Ill Substantially  Similar PROTOTYPEyp tNON
QID
  ,to Valid-Prototype                              but omeompoent                /     /Substantially   Similar to differences                                       Conditional Prototype Analysis and Either                Analysis, Limited                       //Analysis,             Limited Extensive Measurements              Measurements, and                 .A 1'Measurements, and or Full Inspection                 Full Inspection                  M' I.                Full Inspection II
J Inservice problems resulting in component or Vlid :Proto"  
                                                                      Limited Valid Prototype NON-PROTOTYPE
prtoa oiiain Conditional NON-PROTOTYPE  
                                                                    CATEGORCYIV
\\INON-PROTOTYPE  
                                                                Similar        Substantially Similar to Limited Valdid Prototype Reatocofiuraio ineral        fr wiccoprhestn      iveySiiart Analysis and    Either Extensive Measurements or Full Inspection GIlD                  Reactor internals configuration for which comprehensive vibration assessment program is defined.
CATEGORY II  
CTGR  
Similar to ValidPrototype CTG  
Ill but ome ompoent
/  
/Substantially Similar to differences Conditional Prototype  
//
Analysis, Limited  
//Analysis, Limited Measurements, and  
.A 1'Measurements, and Full Inspection M' I.


EZZJ                Summary of comprehensive vibration assessment programs.
Full Inspection Limited Valid Prototype NON-PRO TOTYPE
CATEGORCYIV
Similar Substantially Similar to Limited Valdid Prototype Analysis and Either Extensive Measurements or Full Inspection Reato ineral cofiuraio fr wiccoprhestn iveySiiart Reactor internals configuration for which comprehensive vibration assessment program is defined.


QID
Summary of comprehensive vibration assessment programs.
                      Reactor internals reference design which, together with its test and operating experience, provides the basis for a specific comprehensive vibration assessment program.
 
Reactor internals reference design which, together with its test and operating experience, provides the basis for a specific comprehensive vibration assessment program.


Indicates alternative paths}}
Indicates alternative paths II}}


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Latest revision as of 02:08, 17 January 2025

Comprehensive Vibration Assessment Program for Reactor Internals During Preoperational and Initial Startup Testing
ML003739957
Person / Time
Issue date: 05/31/1976
From:
Office of Nuclear Regulatory Research
To:
References
RG-1.20, Rev 2
Download: ML003739957 (9)
v • d • e


U.S. NUCLEAR REGULATORY COMMISSION

REGULATORY GUIDE

OFFICE OF STANDARDS DEVELOPMENT

REGULATORY GUIDE 1.20

COMPREHENSIVE VIBRATION ASSESSMENT PROGRAM

FOR REACTOR INTERNALS DURING

PREOPERATIONAL AND INITIAL STARTUP TESTING

A. INTRODUCTION

Criterion 1, "Quality Standards and Records," of Appendix A, "General Design Criteria for Nuclear Power Plants," to 10 CFR Part 50, "Licensing of Production and Utilization Facilities,"

requires that structures, systems, and components important to safety be designed, fabricated, erected, and tested to quality standards commensurate with the importance of the safety functions to be performed. Section 50.34, "Con tents of Applications; Technical Information," of 10

CFR Part 50 requires the applicant to determine and to specify the margin of safety associated with normal operation and anticipated operating transients.

This guide presents a method acceptable to the NRC

  • -'

staff for implementing the above requirements with respect to the internals of light-water-cooled reactors'

during preoperational and initial startup testing.2 Inser vice inspections and inservice monitoring programs to verify that the reactor internal components have not been subjected to structural degradation as a result of vibration during normal reactor operation are not I covered by this guide. The Advisory Committee on Reactor Safeguards has been consulted concerning this guide and has concurred in the Regulatory Position.

lReactor internals, as used in this regulatory guide, comprise core support structures and adjoining internal structures. Core support and internal structures are defined in Article NG-1120

of Section III (Nuclear Power Plant Components) of the ASME

Boiler and Pressure Vessel Code.

konsistent with Regulatory Guide 1.68, "Preoperational and Initial Startup Test Programs for Water-Cooled Power Reactors," preoperational testing as used in this guide consists of those tests conducted prior to fuel loading, and intial startup testing refers to those tests performed after fuel loading.

  • Lines indicate substantive changes from previous issue.

B. DISCUSSION

Reactor internals important to safety are designed to accommodate steady-state and transient vibratory loads for the service life of the reactor. This guide presents a comprehensive vibration assessment program for use in verifying the structural integrity of the reactor internals for 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 to emphasize that the individual programs should be used cooperatively to verify structural integrity and to estab lish the margin of safety. For example, the analytical program not only should be used to provide theoretical verification of structural integrity but also should be the basis for the choice of components and areas to be monitored in the measurement and inspection programs;

the measurement program should be used to confirm the analysis, but the program (i.e., data acquisition, reduc tion, interpretation processes) should be sufficiently flexible to permit definition of any significant'vibratory modes that are present but were not included in the analysis; the inspection program should be considered and used as a powerful tool for quantitative (e.g., as an indicator of maximum total relative motion) as well as qualitative (e.g., establishment of boundary conditions by inspection evidence at component interfaces) verifica tion of both the analytical and measurement program results.

The original guidelines of Regulatory Guide 1.20

were refined in Revision 1 to incorporate items that would expedite review of the applicant's vibration assessment program by the NRC staff. Generally, this was accomplished by increased specificity in the guide lines for the vibration analysis, measurement, and inspection programs and by inclusion of guidelines for USNRC REGULATORY GUIDES

Comments should be sent to the Secretary of the Commission. U.S. Nuclear Regulatory Guides are issued to describe and make available to the public Regulatory Commissiooi.

Washington. D.C

20566. Attention Docketing and methods acceptable to the NRC staff of implementing specific parts of the Service Section Commission's regulations, to delineate techniques used by the staff in evalu The guides are issued in the following ten broad divisions:

sting specific problems or postulated accidents, or to provide guidance to appli.

cants. Regulatory Guides are not substitutes for regulations, and compliance

1. Power Reactors

6. Products with them is not required. Methods and solutions different from those set out in

2. Research and Test Reactors

7. Transportation the guides will be acceptable if they provide a basis for the findings requisite to

3. Fuels and Materials Facilities

8. Occupa,.onal Health the issuance or continuance of a permit or license by the Commission.

4. Environmental and Siting

8. Antitrust Review Comments and suggestions for improvements in these guides are encouraged

5. Materials and Plant Protection

10. General at all times, and guides will be revised, as appropriate, to accommodate com ments and to reflect new information or experience. This guide was revised as a Copies of published guides may be obtained by written request indicating the result of substantive comments received from the public and additional staff divisions desired to the U.S. Nuclear Regulatory Commission. Washington. D.C.

review.

20566. Attention: Director. Office of Standards Development.

Revision 2 May 1976

scheduling significant phases of the comprehensive vibra tion assessment program.

The original guidelines served as the basis for testing many prototype and similar-to-prototype (referred to in this guide as non-prototype) reactor internals. Operating experience and the tendency for the design of sub sequent reactor internals to differ somewhat from that of the initially designated prototypes, in some instances, made the basic prototype and non-prototype classifica tions difficult to apply, resulting in the need for time-consuming case-by-case resolution of reactor inter nal classifications and corresponding vibration assess ment programs.

Revision 1 expanded on the previous classifications and outlined an appropriate comprehensive vibration assessment program for each class. The classifications are defined in regulatory position C. I below. In general, the expanded classifications and corresponding programs allow for the use, under certain conditions, of prototype reactor internals that have experienced some adverse inservice vibration phenomena as limited prototypes and for the use, under certain conditions, of reactor internals that are in some respects structurally dissimilar from the designated prototype as limited non-prototypes. The expanded classifications make the use of this guide compatible with design and operating experience. Revi sion 2 retains the expanded classifications of Revision 1.

Some changes in the corresponding vibration assessment programs and in the reporting of results were made as a result of substantive public comments and additional staff review.

C

Q. REGULATORY POSITION

The classifications provided in regulatory position C. I

should be used by the applicant to categorize the reactor internals according to design, operating parameters, and the operating experience of potential prototypes. The appropriate comprehensive vibration assessment program should then be established from the guidelines specified for that classification in the succeeding selections of this guide. The comprehensive vibration assessment programs outlined in this guide are summarized in Figure 1.

1. Classification of Reactor Internals Relative to the Comprehensive Vibration Assessment Program

1.1 Prototype. A reactor internals configuration, that, because of its arrangement, design, size, or operat ing conditions, represents a first-of-a-kind or unique design for which no Valid Prototype exists.

1.2 Valid Prototype. A reactor internals config uration that has successfully completed a comprehensive vibration assessment program for Prototype reactor internals and has experienced no adverse inservice vibration 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 Prototype that later experiences adverse inservice vibration phenomena and subsequently has been modified in arrangement, design, size, or operating conditions is designated a Conditional Prototype. Upon satisfying conditions described elsewhere in this guide, the Condi tional Prototype serves as the reference design for Non-Prototype, Category III and IV, reactor internals configurations.

1.4 Non-Prototype, Category I. A reactor inter nals configuration with substantially the same arrange ment, design, size, and operating conditions as a specified 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 no significant effect on the vibriatory response and excitation of those reactor internals important to safety.

1.5 Non-Prototype, Category II.

A

reactor internals configuration with substantially the same size and operating conditions as a specified Valid Prototype, but with some component arrangement or design differ ences that are shown by test or analysis to have no significant effect on the vibratory response and excita tion of those unmodified reactor internals important to safety.

1.6 Limited Valid Prototype. A Non-Prototype, Category II or III, reactor internals configuration that has successfully conrpleted the appropriate comprehen sive vibration assessment program and has itself experi enced no adverse inservice vibration phenomena. An operating Valid Prototype that has demonstrated extended satisfactory inservice operation subsequent to a design modification may be considered a Limited Valid Prototype relative to the modified reactor internals configuration. A Conditional Prototype that has demon strated extended satisfactory inservice operation may be considered a Limited Valid Prototype.

1.7 Non-Prototype, Category III. A reactor inter nals configuration with substantially the same arrange ment, design, size, and operating conditions as a specified Conditional Prototype with insufficient operating history to justify it as a Limited Valid Prototype. Differences in arralpgement, design, size, and operating conditions should be shown by test or analysis to have no significant effect on the vibratory response and excitation of those reactor internals important to safety.

1.8 Non-Prototype, Category IV. A reactor inter nals configuration with substantially the game arrange ment, design, size, and operating conditions as a

1.20-2

Inservice problems resulting in component or operational modifications NON-PROTOTYPE

CATEGORY I

Substantially Similar to Valid Prototype Analysis and Either Extensive Measurements

or P-ull Inspection Valid Prototype modified

\\ Extended satisfactory /

\\ rnservice operation /

-~\\~\\

\\

,/

NON-PROTOTYPE

CATEGORY I I I

Substantially Similar to Conditional Prototype Analysis, Limited Measurements, and Full Inspection NON-PROTOTYPE

CATEGORY IV

Substantially Similar to Limited Valid Prototvoe IZZJ

L I

cm Reactor internals configuration for which comprehensive vibration assessment program is defined.

Summary of comprehensive vibration assessment programs.

Reactor internals reference design which, together with its test and operating experience, provides the basis for a specific comprehensive vibration assessment program.

Indicates alternative paths FIGURE 1 - SUMMARY OF COMPREHENSIVE VIBRATION ASSESSMENT PROGRAMS

1.20-3

specified Limited Valid Prototype, where nominal differ ences in arrangement, design, size, and operating condi tions have been shown by test or analysis to have no significant effect on the vibratory response and excita tion of those reactor internals important to safety.

Associated with the Prototype and the Category I, II,

III, and IV Non-Prototype classifications are the comprehensive vibration assessment programs delineated in regulatory positions C.2 and C.3 and summarized in Figure 1. The foregoing classifications are defined relative to the three prototype reference design classifi cations (i.e., Valid Prototype, Conditional Prototype, Limited Valid Prototype) upon whose design, test, and operating experience the individual comprehensive vibration assessment programs are based.

2. Comprehensive Vibration Assessment Program for Prototype Reactor Internals The comprehensive vibration assessment program should be implemented in conjunction with preopera tional and initial startup testing. It should consist of a vibration analysis, a vibration measurement program, an inspection program, and a correlation of their results.

2.1 Vibration Analysis Program The vibration analysis should be performed for those steady-state and anticipated transient conditions that correspond to preoperational and initial startup test and normal operating conditions. The vibration analysis submittal should include a summary of:

1. The theoretical structural and hydraulic models and analytical formulations or scaling laws and scale models used in the analysis.

2. The structural and hydraulic system natural frequencies and associated mode shapes which may be excited during steady-state and anticipated transient operation.

3. The estimated random and deterministic forcing functions, including any very-low-frequency components, for steady-state and anticipated transient operation.

4. The calculated structural and hydraulic responses for steady-state and anticipated transient operation. (The random, deterministic, overall integrated maximum response, any very-low-frequency components of response, and the level of cumulative fatigue damage should be identified.)

5. A comparison of the calculated structural and hydraulic responses for preoperational and initial startup testing with those for normal operation. (Normal operating conditions that are not accurately or suffi- ciently simulated by the test conditions should be identified.)

6. The anticipated structural or hydraulic vibratory response (defined in terms of frequency, amplitude, and modal contributions) that is appropriate to each of the sensor locations for steady-state and anticipated transient preoperational and startup test conditions.

7. The test acceptance criteria with permissible deviations and the basis for the criteria. (The criteria should be established in terms of maximum allowable response levels in the structure and presented in terms of maximum allowable response levels at sensor locations.)

2.2 Vibration Measurement Program A vibration measurement program should be developed and implemented to verify the structural integrity of the reactor internals, to determine the margin of safety associated with steady-state and antici pated transient conditions for normal operation, and to confirm the results of the vibration analysis. The vibration measurement program should include a description 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 be sufficient to monitor significant lateral, vertical, and torsional structural motions of major reactor internal components in shell, beam, and rigid body modes of vibration, as well as significant hydraulic responses and those parameters that can be used to confirm the input forcing function.

c. Precautions being taken to ensure acquisi tion of quality data (e.g., optimization of signal-to-noise ratio, relationship of recording times to data reduction requirements, choice of instrumentation system).

d. On-line data evaluation system to provide immediate verification of general quality and level of data.

e. Procedures for determining frequency, modal content, and maximum values of response.

2. Test operating conditions, including:

operation.

a. All steady-state and transient modes of

1.20-4

b. The planned duration of all testing in normal operating modes to ensure that each critical component will have been subjected to at least 106 cycles of vibration (i.e., computed at the lowest fre quency for which the component has a significant structural response) prior to the final inspection of the reactor internals. The duration of testing for non prototype reactor internals should be no less than that for the applicable reference reactor internals (i.e., Valid, Conditional, or Limited Valid Prototype).

c. Disposition of fuel assemblies. (Testing should be performed with the reactor internals impor tant to safety and the fuel assemblies (or dummy assemblies which provide equivalent dynamic mass and flow characteristics) in position. The test may be conducted without real or dummy fuel assemblies if it can be shown by analytical or experimental means that such conditions will yield conservative results.)

2.3 Inspection Program The inspection program should provide for inspections of the reactor internals prior to and follow ing operation at those steady-state and transient modes consistent with the test conditions for regulatory position C.2.2.2. The reactor internals should be removed from the reactor vessel for these inspections. If removal is not feasible, the inspections should be performed by means of examination equipment appro priate for in situ inspection. The inspection program should include:

1. A tabulation of all reactor internal compo nents and local areas to be inspected, including:

a. All major load-bearing elements of the reactor internals relied upon to retain the core support structure in position.

b. The lateral, vertical, and torsional restraints provided within the vessel.

c. Those locking and bolting components whose failure could adversely affect the structural integrity of the reactor internals.

d. Those surfaces that are known to be or may become contact surfaces during operation.

e. Those critical locations on the reactor internal components as identified by the vibration analysis.

f. The interior of the reactor vessel for evidence of loose parts or foreign material.

2. A tabulation of specific inspection areas that can be used to verify segments of the vibration analysis and measurement program.

3. A description of the inspection procedure, including the method of examination (e.g., visual and nondestructive surface examinations), method of docu mentation, access provisions on the reactor internals, and specialized equipment to be employed during the inspections to detect and quantify evidence of the effects of vibration.

2.4 Documentation of Results The results of the vibration analysis, measure ment, and inspection programs should be reviewed and correlated to determine the extent to which the test acceptance criteria are satisfied. A summary of the results should be submitted to the Commission in the form of preliminary and final reports.

1. The preliminary report should summarize an evaluation of the raw and, as necessary, limited proc essed data and the results of the inspection program with respect to the test acceptance criteria. Anomalous data that could bear on the structural integrity of the reactor internals should be identified, as should the method to be used for evaluating such data.

2. If the results of the comprehensive vibration assessment program are acceptable, the final report should include:

a. A description of any deviations from the specified measurement and inspection programs, including instrumentation reading and inspection anomalies, instrumentation malfunctions, and deviations from the specified operating conditions, b. A comparison between the measured and analytically determined modes of structural and hydraulic response (including those parameters from which the input forcing function is determined) for the purpose of establishing the validity of the analytical technique, c. A determination of the margin of safety associated with normal steady-state and anticipated transient operation, d. An evaluation of measurements that exceeded acceptable limits not specified as test acceptance criteria or of observations that were unantici pated and the disposition of such deviations.

3. If (1) inspection of the reactor internals reveals defects, evidence of unacceptable motion, excessive or undue wear, (2) the results from the

1.20-5

measurement program fail to satisfy the specified test acceptance criteria, or (3) the results from the analysis, measurement, and inspection programs are inconsistent, the final report should also include an evaluation and description of the modifications or actions planned in order to justify the structural adequacy of the reactor internals.

4. The collection, storage, and maintenance of all records relevant to the analysis, measurement, and inspection phases of the comprehensive vibration assess ment program should be consistent with Regulatory Guide 1.88, "Collection, Storage, and Maintenance of Nuclear Power Plant Quality Assurance Records," which describes a method acceptable to the NRC staff for complying with Criterion XVII, "Quality Assurance Records," of Appendix B, "Quality Assurance Criteria for Nuclear Power Plants and Fuel Reprocessing Plants,"

to 10 CFRPart 50.

2.5 Schedule A schedule should be established and submitted to the Commission during the construction permit review. The schedule should provide that:

1. The reactor internals design will be classified in the Preliminary Safety Analysis Report (PSAR) as a prototype or a specific category of non-prototype. The classification may be revised in the Final Safety Analysis Report if schedule changes with respect to the previ ously designated reference reactor make such reclassifi cation appropriate. (If the internals are classified as non-prototype, the applicant should identify the appli cable prototype reactor internals in the PSAR. Experi mental or analytical justification for the non-prototype classification should be presented during the construc tion permit review.)

2. A commitment will be established during the construction permit review regarding the scope of the comprehensive vibration assessment program.

3. A description of the vibration measurement and inspection phases of the comprehensive vibration assessment program will be submitted to the Com mission in sufficient time to permit utilization of Commission recommendations. (A 90-day comment and review period by the staff should be assumed by the applicant for scheduling purposes.)

4. A summary of the vibration analysis pro gram will be submitted to the Commission a minimum of 60 days prior to submittal of the description of the vibration measurement and inspection programs. (As an alternative, the information in this report may be submitted to the Commission in conjunction with the report specified in regulatory position C.2.5.3. In this case, a 120-day comment and review period for the composite report should be assumed by the applicant for scheduling purposes.)

5. The preliminary and final reports, which together summarize the results of the vibration analysis, measurement, and inspection programs, will be pre sented to the Commission within 60 and 180 days, respectively, of the completion of vibration testing.

3. Comprehensive Vibration Assessment Programs for Non-Prototype Reactor Internals Non-prototype reactor internals important to safety should be subjected during the preoperational and initial startup test program to all significant flow modes associated with normal steady-state and anticipated transient operation under the same test conditions imposed on the applicable prototype. Evaluation of the effects of such operation on the structural integrity of the non-prototype reactor internals should be based on the results of a comprehensive vibration assessment program developed for the specific non-prototype classi fication (i.e., Category I, II, III, or IV). The comprehen sive vibration assessment programs for non-prototype reactor internals are outlined below. These programs should be scheduled and documented in accordance with the guidelines for the program delineated in regulatory positions C.2.4 and C.2.5 for Prototype reactor inter nals.

3.1 Non-Prototype, Category I

3.1.1 Vibration Analysis Program The Valid Prototype should be specified and sufficient evidence should be provided to support the classification Non-Prototype, Category I.

The vibration analysis for the Valid Proto type, which includes a summary of the anticipated structural and hydraulic response and test acceptance criteria, should be modified to account for the nominal differences that may exist between the Non-Prototype, Category I, and Valid Prototype reactor internals.

3.1.2 Vibration Measurement Program The vibration measurement program may be omitted if the inspection program is implemented.

If a measurement program is implemented in lieu of an inspection program, sufficient and appropriate instrumentation should be incorporated to verify that the vibratory response of the Non-Prototype, Category I,

reactor internals is consistent with the results of the vibration analysis, test acceptance criteria, and the vibratory response observed in the Valid Prototype. The vibration measurement program should include a description of the data acquisition and reduction

1.20-6

systems and test operating conditions consistent with the general guidelines for the vibration measurement program delineated in regulatory position C.2.2 for Prototype reactor internals.

3.1.3 Inspection Program If an inspection program is implemented in lieu of a vibration measurement program, the guidelines for the inspection program delineated in regulatory position C.2.3 for Prototype reactor internals should be followed.

The inspection program may be omitted if the vibration measurement program is implemented.

However, if significant discrepancies exist between anticipated and measured responses for specific compo nents, those components should be removed from the reactor vessel and a visual examination performed.

Components for which removal is not feasible should be examined in situ by means of appropriate inspection equipment. In any case, the interior of the reactor vessel should be visually checked for loose parts and foreign material.

3.2 Non-Prototype, Category II

3.2.1 Vibration Analysis Program and The Valid Prototype should be specified, and sufficient evidence should be provided to support the classification Non-Prototype, Category II, which requires demonstrating that the structural differences that exist between the Non-Prototype, Category II,

and Valid Prototype reactor internals have no significant effect on the vibratory response and excitation of those unmodified Non-Prototype, Category II, components.

The vibration analysis for the Valid Proto type, which includes a summary of the anticipated structural and hydraulic response and test acceptance criteria, should be modified to account for the structural differences that exist between the Valid Prototype and Non-Prototype, Category 1I, reactor internals.

Test acceptance criteria should specifically be established for those Non-Prototype, Category II,

reactor internal components with structural differences relative to the Valid Prototype.

3.2.2 Vibration Measurement Program A vibration measurement program should be implemented on the Non-Prototype, Category II, reactor internals during preoperational and initial startup testing.

The vibration measurement program should include a description of the data acquisition and reduction systems and test operating conditions con sistent with the general guidelines for the vibration measurement program delineated in regulatory position C.2.2 for Prototype reactor internals.

Sufficient and appropriate instrumentation should be used to define the vibratory response (i.e.,

frequency, amplitude, modal content) of those reactor internal components important to safety that have been modified relative to the Valid Prototype for the purpose of demonstrating that the test acceptance criteria are satisfied and establishing the margin of safety.

Sufficient and appropriate instrumentation should be used to monitor those reactor internal components important to safety that have not been modified relative to the Valid Prototype to confirm that the vibratory response of such components complies with the guidelines for Non-Prototype, Category II,

reactor internals and is consistent with the results obtained for similar components during the measure ment program on the Valid Prototype.

3.2.3 Inspection Program An inspection program that follows the guidelines for the inspection program delineated in regulatory position C.2.3 for Prototype reactor internals should be implemented.

3.3 Non-Prototype, Category HI

3.3.1 Vibration Analysis Program The Conditional Prototype should be specified, and sufficient analytical or experimental evidence should be provided to support the classification Non-Prototype, Category III, as well as to demonstrate the applicability of data from the vibration measurement program on the Prototype to the Conditional Prototype.

It should be demonstrated that:

1. The Conditional Prototype is sub stantially similar in arrangement, design, size, and operating conditions to the Non-Prototype, Category III,

reactor internals.

2. Response modes attributable to the inservice vibration problems and ensuing component or operational modifications do not significantly affect the applicability of the results of the vibration measurement program on the Prototype to the Conditional Prototype, or response modes attributable to the inservice vibration problems and ensuing component or operational modifi cations do affect the applicability of the results of the vibration measurement program on the Prototype to the Conditional Prototype, but the effects are limited to structural components and response modes that permit

1.20-7

clear separation of these effects from other results of the vibration measurement program.

Details concerning the adverse vibration experience of the Conditional Prototype should be provided, as should experimental or analytical informa tion which demonstrates that the vibration problems associated with the Conditional Prototype have been corrected for both it and the applicable Non-Prototype, Category III, reactor internals.

The vibration analysis on the Prototype to the Conditional Prototype, which includes a summary of the anticipated structural and hydraulic response and test acceptance criteria for the measurement program on the Prototype, should be modified to account for the component or operational modifications applicable to the Conditional Prototype and Non-Prototype, Category III, reactor internals.

Test acceptance criteria, with permissible deviations, should be specified for reactor internal components important to safety. Each component should be categorized according to whether the results from the vibration measurement program on the Proto type to the Conditional Prototype are applicable.

3.3.2 Vibration Measurement Program A vibration measurement program should be implemented on the Non-Prototype, Category III,

reactor internals during preoperational and initial startup testing.

Sufficient and appropriate instrumentation should be used to define the vibratory response of those reactor components important to safety which, because of structural or operational modifications relative to the original design of the Conditional Prototype, are expected to have response characteristics substantially different from those measured for that component during the vibration measurement program on the Prototype to the Conditional Prototype.

All other components should be monitored with sufficient and appropriate instrumentation to con firm that the measured response for each component is substantially similar to that obtained during the vibra tion measurement program on the Prototype to the Conditional Prototype.

The vibration measurement program should satisfy the general guidelines for a Prototype measure ment program as delineated in regulatory position C.2.2.

3.3.3 Inspection Program An inspection program that satisfies the guidelines for the inspection program delineated in regulatory position C.2.3 for Prototype reactor internals should be implemented.

3.4 Non-Prototype, Category IV

3.4.1 Vibration Analysis Program The Limited Valid Prototype should be specified, and sufficient evidence should be provided to support the classification Non-Prototype, Category IV.

3.4.2 Vibration Measurement Program A vibration measurement program may be omitted if the inspection program is implemented.

If a measurement program is implemented in lieu of an inspection program, sufficient and appropriate instrumentation should be incorporated to verify that the vibratory response of the Non-Prototype, Category IV, reactor internals is consistent with the results of the vibration analysis, test acceptance criteria, and the vibratory response for the referenced limited Valid Prototype.

The vibration measurement program should be consistent with the guidelines delineated in regulatory position C.3.1.2 for the measurement program for Non-Prototype, Category I, reactor internals.

3.4.3 Inspection Program If an inspection program is implemented in lieu of a vibration measurement program, the guidelines for the inspection program delineated in regulatory position C.3.1.3 for Non-Prototype, Category I, reactor internals should be followed.

D. IMPLEMENTATION

The purpose of this section is to provide guidance to applicants and licensees regarding the NRC staffs plans for utilizing this regulatory guide.

Except in those cases in which the applicant proposes an acceptable alternative method for complying with specified portions of the Commission's regulations, the method described herein will be used in the evaluation of submittals for operating license or construction permit applications docketed after June 22, 1976.

If an applicant wishes to use this regulatory guide in developing submittals for applications docketed on or before June 22, 1976, the pertinent portions of the application will be evaluated on the basis of this guide.

1.20-8

SPROTOTYPE

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Similar Substantially Similar to Limited Valdid Prototype Analysis and Either Extensive Measurements or Full Inspection Reato ineral cofiuraio fr wiccoprhestn iveySiiart Reactor internals configuration for which comprehensive vibration assessment program is defined.

Summary of comprehensive vibration assessment programs.

Reactor internals reference design which, together with its test and operating experience, provides the basis for a specific comprehensive vibration assessment program.

Indicates alternative paths II


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