Regulatory Guide 1.20

Comprehensive Vibration Assessment Program for Reactor Internals During Preoperational and Initial Startup Testing

ML13350A367
Person / Time
Issue date:	06/30/1975
From:	NRC/OSD
To:
References
RG-1.020, Rev. 1
Download: ML13350A367 (8)

Revision 1 U.S. NUCLEAR REGULATORY COMMISSION June 1975 REGULATORY GUIDE

OFFICE OF STANDARDS DEVELOPMENT

REGULATORY GUIDE 1.20

COMPREHENSIVE VIBRATION ASSESSMENT PROGRAM

FOR REACTOR INTERNALS DURING

PREOPERATIONAL AND INITIAL STARTUP TESTING

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 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;

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 vibration during normal reactor operation are not modes that are present but were not included in the covered by this guide. 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-

'Reactor internals, as used in this regulatory guide, comprise tion of both the analytical and measurement program core support structures and adjoining internal structures. Core results.

support and internal structures are defined in Article NG-I 120

of Section 111 (Nuclear Power Plant Components) of the ASME

Boiler and Pressure Vessel Code.

The original guidelines of Regulatory Guide 1.20 have kConsistent with Regulatory Guide 1.68, "Preoperational and been refined in this revision to incorporate items that Initial Startup Test Programs for Water-Cooled Power will expedite review of the applicant's vibration assess- Reactors," preoperational testing as used in this guide consists of those tests conducted prior to fuel loading, and intial startup ment program by the NRC staff. Generally, this has been testing refers to those tests performed after fuel loading. accomplished by increased specificity in the guidelines USNRC REGULATORY GUIDES Comments should be sent to the Secretary of the Commission. U.S. Nuclear Regulatory Guide% ate issud to describe and matte available to the publc Regulatory Commission. Washington, D.C. 20566. Attention Dockelting and methods acceptable tO the NRC staff of implementing specific pans of the Service Section.

Commisson's regulations. In delineate techniques used by the staff in vavlu The guides are Issued in the following ten broad divisions sling specsifc problems or postulated accidents, or to provide guidance to oppli cants Regulatory Guides are not substitutes lor regulations. and compliance I. Power Reactors 6, Products w"th therr is no. required. Methods and solutions dilterent from those set out in 2 Research and Test Reactors 7. Transportation the gurdes will be acceptable if they provide a basis tor the findings requisita to 3. Fuels and Materials Facilities S. Occupational Health the tsluence or continuance of a permit or license by the Commission 4. Environmental and Siting 9. Antltrust Review Comments and suggestions for improvements in these guide% are encourageo S Materials and Plant Protection 10. Genteal at all times. and guides wilt be tewised. as eppropriate, to accommodate corn ments and to reflect new informatton or eaperience However, comments on Copies of published guides may be obtained by written request indicating the thins gurde. If recersed within about two months ailts ats issuance. will be par divisions desired to the U.S. Nuclear RegulatotV Commission. Washinglon. 0 C.

Kcuterly useful in evaluating the need for an early tevismon 2066M. AttentloA. Direitor. Of tice of Standards Development

for the vibration analysis, measurement, and inspection sequently modified in design (e.g., as in item 1.3 below)

programs and by inclusion of guidelines for scheduling remains a Valid Prototype relative to its original design.

significant phases of the comprehensive vibration assess- ment program. 1.3 Conditional Prototype. A Valid Prototype that later experiences adverse inservice vibration The original guidelines served as the basis for testing phenomena and subsequently has been modified in many prototype and similar-to-prototype (referred to in arrangement, design, size, or operating conditions is this guide as non-prototype) reactor internals. Operating designated a Conditional Prototype. Upon satisfying experience and the tendency for the design of sub- conditions described elsewhere in this guide, the Condi- sequent reactor internals to differ somewhat from that tional Prototype serves as the reference design for of the initially designated prototypes have, in some Non-Prototype, Category Ill and IV, reactor internals instances, made the basic prototype and non-prototype configurations.

classifications difficult to apply, resulting in the need for

• time-consuming case-by-case resolution of reactor 1.4 Non-Prototype, Category 1. A reactor inter- internal classifications and corresponding vibration nals configuration with substantially the same arrange- assessment programs. ment, design., size, and operating conditions as a specified Valid Prototype and for which nominal differ- This revision expands on the previous classifications ences in arrangement, design, size, and operating condi- and outlines an appropriate comprehensive vibration tions have been shown by test or analysis to have no assessment program for each class. The new classifica- significant effect on the vibratory response and tions are defined in regulatory position C.A below. In excitation of those reactor internals important to safety.

general, the expanded classifications and corresponding programs allow for the use, under certain conditions, of 1.5 Non-Prototype, Category II. A reactor prototype reactor internals that have experienced some internals configuration with substantially the same size adverse inservice vibration phenomena as limited proto- and operating conditions as a specified Valid Prototype, types and for the use, under certain conditions, of but with some component arrangement or design differ- reactor internals that are in some respects structurally ences that are shown by t.-st or analysis to have no dissimilar from the designated prototype as limited significant effect on the vibratory response and excita- non-prototypes. The expanded classifications will make tion of those unmodified reactor internals important to the use of this guide compatible with design and safety.

operating experience.

1.6 Limited Valid Prototype. A Non-Prototype, Category 11 or Ill, reactor internals configuration that

C. REGULATORY POSITION

has successfully completed the appropriate comprehen- sive vibration assessment program and has itself experi- The classifications provided in regulatory position C.1 enced no adverse inservice vibration phenomena. An should be used by the applicant to first categorize the operating Valid Prototype that has demonstrated reactor internals according to design, operating param- extended satisfactory inservice operation subsequent to a eters, and the operating experience of potential proto- design modification may be considered a Limited Valid typed. The appropriate comprehensive vibration Prototype relative to the modified reactor internals assessment program should then be established from the configuration. A Conditional Prototype that has demon- guidelines specified for that classification in the succeed- strated extended satisfactory inservice operation may be ing sections of this guide. The comprehensive vibration considered a Limited Valid Prototype.

assessment programs outlined in this guide are sum- marized in Figure 1. 1.7 Non-Prototype, Category 111. A reactor inter- nals configuration with substantially the same arrange-

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 operating history to justify it as a Limited Valid

1.1 Prototype. A reactor internals configuration, Prototype. Differences in arrangement, design, size, and that, because of its arrangement, design, size, or operat- operating conditions should be shown by test or analysis ing conditions, represents a first-of-a-kind or unique to have no significant effect on the vibratory response design for which no Valid Prototype exists. and excitation of those reactor internals important to safety.

1.2 Valid Prototype. A reactor internals config- uration that has successfully completed a comprehensive 1.8 Non-Prototype, Category IV. A ieactor inter- vibration assessment program for Prototype reactor nals configuration with substantially the same arrange- internals and has experienced no adverse inservice ment, design, size, and operating conditions as a vibration phenomena. A Valid Prototype that is sub- specified Limited Valid Prototype, where nominal differ-

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

01I Summary of comprehensive vibration assessment programs.

QD 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 I - SUMMARY OF COMPREHENSIVE VIBRATION ASSESSMENT PROGRAMS

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ences in arrangement, design, size, and operating condi. ciently simulated by the test conditions should be tions have been shown by test or analysis to have no identified.)

significant effect on the vibratory response and excita- tion of those reactor internals important to safety. 6. The anticipated structural or hydraulic vibratory response (defined in terms of frequency, Associated with the Prototype and the Category 1,11, amplitude, and modal contributions) that is appropriate III, and IV Non-Prototype classifications are the to each of the sensor locations for steady-state and comprehensive vibration assessment programs delineated anticipated transient preoperational and startup test in regulatory positions C.2 and C.3 and summarized in conditions.

Figure 1. The foregoing classifications are defined relative to the three prototype reference design classifi- 7. The test acceptance criteria with permissible cations (i.e., Valid Prototype, Conditional Prototype, deviations and the basis for the criteria. (The criteria Limited Valid Prototype) upon whose design, test, and should be established in terms of maximum allowable operating experience the individual comprehensive response levels in the structure and presented in terms of vibration assessment programs are based. maximum allowable response levels at sensor locations.)

.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 description of:

The vibration analysis should be performed for those steady-state and anticipated transient conditions 1. The data acquisition and reduction system, that correspond to preoperadional 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 scale models used in the analysis. sufficient to monitor significant lateral, vertical, and torsional structural motions of major reactor internal

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 define the input forcing operation. function.

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 operation. requirements, choice of instrumentation system).

4. The calculated structural and hydraulic d. On-line data evaulation 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.

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.

5. A comparison of the calculated structural 2. Test operating conditions, including:

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.

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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 1O0 and measurement program.

cycles of vibration (i.e., computed at the component's minimum significant response frequency) prior to the 3. A description of the inspection procedure, final inspection of the reactor internals. (If it is not including the method of examination (e.g., visual and feasible to perform an inspection following the accumu- nondestructive surface examinations), method of docu- lation of 107 cycles, the structural integrity of the mentation, access provisions on the reactor internals, reactor internals should be verified by measurements and specialized equipment to be employed during the which demonstrate that no significant change in struc- inspections to detect and quantify evidence of the tural response resulting from component damage has effects of vibration.

occurred between the time vibration testing was initiated and after 107 cycles were accrued.)

c. Disposition of fuel assemblies. (Testing 2.4 Documentation of Results should be performed with the reactor internals impor- tant to safety and the fuel assemblies (or dummy The results of the vibration analysis, measure- assemblies which provide equivalent dynamic mass and ment, and inspection programs should be reviewed and flow characteristics) in position. The test may be correlated to determine the extent to which the test conducted without real or dummy fuel assemblies if it acceptance criteria are satisfied. A summary of the can be shown by analytical or experimental means that results should be submitted to the Commission as such conditions will yield conservative results.) follows:

2.3 Inspection Program 1. If the results of'the comprehensive vibration assessment program are acceptable, the final report The inspection program should provide for should include:

inspections of the reactor internals prior to and follow- ing operation at those steady-state and transient modes a. A description of any deviations from the consistent with the test conditions for regulatory specified measurement and inspection programs, position C.2.2.2. The reactor internals should be including instrumentation reading and inspection removed from the reactor vessel for these inspections. If anomalies, instrumentation malfunctions, and deviations removal is not feasible, the inspections should be from the specified operating conditions, performed by means of examination equipment appro- priate for in situ inspection. The inspection program b. A comparison between the measured and should include: analytically determined modes of structural and hydraulic response (including those parameters from

1. A tabulation of all reactor internal compo- which the input forcing function is determined) for the nents .,..d iocal areas to be inspected, including: purpose of establishing the validity of the analytical technique, a. All major load-bearing elements of the reactor internals relied upon to retain the core support c. A determination of the margin of safety structure in position. associated with normal steady-state and anticipated transient operation, b. The lateral, vertical, and torsional restraints provided within the vessel. d. An evaluation of measurements that exceeded acceptable limits not specified as test c. Those locking and bolting components acceptance criteria or of observations that were unantici- whose failure could adversely affect the structural pated and the disposition of such deviations.

integrity of the reactor internals.

2. If (1) inspection of the reactor internals d. Those surfaces that are known to be or reveals defects, evidence of unacceptable motion, may become contact surfaces during operation. excessive or undue wear, (2) the results from the measurement program fail to satisfy the specified test e. Those critical locations on the reactor acceptance criteria, or (3) the results from the analysis, internal components as identified by the vibration measurement, and inspection programs are inconsistent, analysis. the final report should also include an evaluation and description of the modifications or actions planned in f. The interior of the reactor vessel for order to justify the structural adequacy of the reactor evidence of loose parts or foreign material. internals.

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The collection, storage, and maintenance of effects of such operation on the structural integrity of all records relevant to the analysis, measurement, and the non-prototype reactor internals should be based on inspection phases of the comprehensive vibration assess- the results of a comprehensive vibration assessment ment program should be consistent with Regulatory program developed for the specific non-prototype classi- Guide 1.88, "Collection, Storage, and Maintenance of fication (i.e., Categcry 1, 1I, Ill, or IV). The comprehen- Nuclear Power Plant Quality Assurance Records," which sive vibration assessmcnt programs for non-prototype describes a method acceptable to the NRC staff for reactor internals are outlined below. These programs complying with Criterion XVII, "Quality Assurance should be scheduled and documented in accordance with Records," of Appendix B, "Quality Assurance Criteria the guidelines for the program delineated in regulatory for Nuclear Power Plants and Fuel Reprocessing Plants," positions C.2.4 and C.2.5 for Prototype reactor inter- to 10 CFR Part 50. nals.

2.5 Schedule 3.1 Non-Prototype, Category I

A schedule should be established and submitted 3.1.1 Vibration Analysis Program to the Commission during the construction permit review. The schedule should provide that: The Valid Prototype should be specified and sufficient evidence should be provided to support the

1. The reactor internals design will be classified classification Non-Prototype, Category 1.

in the Preliminary Safety Analysis Report (PSAR) as a prototype or a specific category of non-prototype. (If The vibration analysis for the Valid Proto- the internals are classified as non-prototype, the appli- type, which includes a summary of the anticipated cant should identify the applicable prototype reactor structural and hydraulic response and test acceptance internals in the PSAR. Experimental or analytical criteria, should be modified to account for the nominal justification for the non-prototype classification should differences that may exist between the Non-Prototype, be presented during the construction permit review.) Category I, and Valid Prototype reactor internals.

2. A commitment will be established during 3.1.2 Vibration Measurement Program the construction permit review regarding the scope of the comprehensive vibration assessment program. The vibration measurement program may be omitted if the inspection program is implemented.

3. A description of the vibration measurement and inspection phases of the comprehensive vibration If a measurement program is implemented in assessment program will be submitted to the Com- lieu of an inspection program, sufficient and appropriate mission in sufficient time to permit utilization of instrumentation should be incorporated to verify that Commission recommendations. (A 90-day comment and the vibratory response of the Non-Prototype, Category 1, review period by the staff should be assumid by the reactor internals is consistent with the results of the applic~ant for scheduling purposes.) vibration analysis, test acceptance criteria, and the vibratory response observed in the Valid Prototype. The

4. A summary of the vibration analysis pro- vibration measurement program should include a gram will be submitted to the Commission a minimum description of the data acquisition and reduction of 60 days prior to submittal of the description of the systems and test operating conditions consistent with vibration measurement and inspection programs. the general guidelines for the vibration measurement program delineated in regulatory position C.2.2 for

5. The final report, which summarizes the Prototype reactor internals.

results of the vibration analysis, measurement, and inspection programs, will be presented to the Com- 3.1.3 Inspection Program mission within 120 days of the completion of vibration testing, If an inspection program is implemented in lieu of a vibration measurement program, the guidelines

3. Comprehensive Vibration Assessment Programs for the inspection program delineated in regulatory for Non-Prototype Reactor Internals position C.2.3 for Prototype reactor internals should be followed.

Non-prototype reactor internals important to safety should be subjected during the preoperational and The inspection program may be omitted if initial startup test program to all significant flow modes the vibration measurement program is implemented.

associated with normal steady-state and anticipated However, if significant discrepancies exist between transient operation under the same test conditions anticipated and measured responses for specific compo- imposed on the applicable prototype. Evaluation of the nents, those components should be removed froin the

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reactor vessel and a visual examination performed. with the guidelines for Non-Prototype, Category 11, 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.

should be visually checked for loose parts and foreign material. 3.2.3 Inspection Program

3.2 Non-Prototype, Category 11 An inspection program that follows the guidelines for the inspection program delineated in

3.2.1 Vibration Analysis Program regulatory position C.2.3 for Prototype reactor internals should be implemented.

The Valid Prototype should be specified, and sufficient evidence should be provided to support 3.3 Non-Prototype, Category III

the classification Non-Prototype, Category II, which requires demonstrating that the structural differences 3.3.1 Vibration Analysis Program that exist between the Non-Prototype, Category II,

and Valid Prototype reactor internals have no significant The Conditional Prototype should be effect on the vibratory response and excitation of those specified, and sufficient analytical or experimental unmodified Non-Prototype, Category Ii, components. evidence should be provided to support the classification Non-Prototype, Category I11, as well as to demonstrate The vibration analysis for the Valid Proto- the applicability of data from the vibration measurement type, which includes a summary of the anticipated program on the Prototype to the Conditional Prototype.

structural and hydraulic response and test acceptance It should be demonstrated that:

criteria, should be modified to account for the structural differences that exist between the Valid Prototype and 1. The Conditional Prototype is sub- Non-Prototype, Category !1,reactor internals. stantially similar in arrangement, design, size, and operating conditions to the Non-Prototype, Category Ill.

Test acceptance criteria should specifically reactor internals.

be established for those Non-Prototype, Category II,

reactor internal components with structural differences 2. Response modes attributable to the relative to the Valid Prototype. inservice vibration problems and ensuing component or operational modifications do not significantly affect the

3.2.2 Vibration Measurement Program applicability of the results of the vibration measurement program on the Prototype to the Conditional Prototype, A vibration measurement program should be or response modes attributable to the inservice vibration implemented on the Non-Prototype, Category II, reactor problems and ensuing component or operational modifi- internals during preoperational and initial startup cations do affect the applicability of the results of the testing. vibration measurement program on the Prototype to the Conditional Prototype, but the effects are limited to The vibration measurement program should structural components and response modes that permit include a description of the data acquisition and clear separation of these effects from other results of the reduction systems and test operating conditions con- vibration measurement program.

sistent with the general guidelines for the vibration measurement program delineated in regulatory position Details concerning the adverse vibration C.2.2 for Prototype reactor internals. experience of the Conditional Prototype should be provided, as should experimental or analytical informa- Sufficient and appropriate instrumentation tion which demonstrates that the vibration problems should be used to define the vibratory response (i.e., associated with the Conditional Prototype have been frequency, amplitude, modal content) of those reactor corrected for both it and the applicable Non-Prototype.

internal components important to safety that have been Category Ill, reactor internals.

modified relative to the Valid Prototype for the purpose of demonstrating that the test acceptance criteria are The vibration analysis on the Prototype to satisfied and establishing the margin of safety. the Conditional Prototype, which includes a summary ot'

the anticipated structural and hydraulic response and Sufficient and appropriate instrumentation test acceptance criteria for the measurement program on should be used to monitor those reactor internal the Prototype, should be modified to account for the components important to safety that have not been component or operational modifications applicable to moc'ified relative to the Valid Prototype to confirm that the Conditional Prototype and Non-Prototype, Category the vibratory response of such components complies Ill, reactor internals.

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Test acceptance criteria, with permissible 3.4.2 Vibration Measurement Program deviations, should be specified for reactor internal components important to safety. Each component A vibration measurement program may be should be categorized according to whether the results omitted if the inspection program is implemented.

from the vibration measurement program on tie Proto- type to the Conditional Prototype are applicable. If a measurement program is implemented in lieu of an inspection program, sufficient and appropriate

3.3.2 Vibration Measurement Program instrumentation should be incorporated to verify that the vibratory response of the Non-Prototype, Category A vibration measurement program should be IV, reactor internals is consistent with the results of the implemented on the Non-Prototype, Category III, vibration analysis. test acceptance criteria, and the reactor internals during preoperational and initial startup vibratory response for the referenced Limited Valid testing. Prototype.

Sufficient and appropriate instrumentation The vibration measurement program should should be used to define the vibratory response of those be consistent with the guidelines delineated in regulatory reactor components important to safety which, because position C.3.1.2 for the measurement program for of structural or operational modifications relative to the Non-Prototype, Category 1, reactor internals.

original design of the Conditional Prototype, are expected to have response characteristics substantially different from those measured for that component 3.4.3 Inspection Program during the vibration measurement program on the Prototype to the Conditional Prototype. If an inspection program is implemented in lieu of a vibration measurement program, the guidelines All other components should be monitored for the inspection program delineated in regulatory with sufficient and appropriate instrumentation to con- position C.3.1.3 for Non-Prototype, Category 1, reactor firm that the measured response for each component is internals should be followed.

substantially similar to that obtained during the vibia- tion measurement program on the Prototype to the Conditional Prototype.

The vibration measurement program should

D. IMPLEMENTATION

satisfy the general guidelines for a Prototype measure- ment program as delineated in regulatory position C.2.2. The purpose of this section is to provide guidance to applicants and licensees regarding the NRC staff's plans

3.3.3 Inspection Program for utilizing this regulatory guide.

An inspection program that satisfies the Except in those cases in which the applicant proposes guidelines for the inspection program delineated in an acceptable alternative method for complying with regulatory position C.2.3 for PrototN pe reactor internals spc-:ified poitions of the Commission's regulations, the should be implemented.

method described herein will be used in the evaluation

3.4 Non-Prototype, Category IV of submittals for operating license or construction permit applications docketed after August 21, 1975.

3.4.1 Vibration Analysis Program If an applicant wishes to use this regulatory guide in The Limited Valid Prototype should be developing submittals for applications docketed on ur specified, and sufficient evidence should be provided to before August 21, 1975, the pertinent portions of the support the classification Non-Prototype, Category IV. application will be evaluated on the basis of this guide. d

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