Regulatory Guide 1.66: Difference between revisions

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{{#Wiki_filter:"uj October 1973 U.S. ATOMIC ENERGY COMMISSION
{{#Wiki_filter:"uj October 1973 U.S.     ATOMIC ENERGY COMMISSION
REGULATORY
                                REGULATORY
DIRECTORATE  
                                  DIRECTORATE OF REGULATORY STANDARDS
OF REGULATORY  
                                                                                                                                GUIDE
STANDARDS GUIDE REGULATORY  
                                                                  REGULATORY GUIDE 1.66 NONDESTRUCTIVE EXAMINATION OF TUBULAR PRODUCTS
GUIDE 1.66 NONDESTRUCTIVE  
                            A. INTRObUCTION                                           product form. Instead, the code simply states that the products shall be examined by one of several methods General Design Criterion 1, "Quality Standards and                             listed.
EXAMINATION  
OF TUBULAR PRODUCTS A. INTRObUCTION
General Design Criterion  
1, "Quality Standards and Records," of Appendix A, "General Design Criteria for Nuclear Power Plants," to 10 CFR Part 50, requires that structures, systems, and components important to safety he designed, fabricated, erected, and tested to quality standards commensurate with the importance of the safety functions to be performed.


Appendix B, "Quality Assurance Criteria for Nuclear Power Plants and Fuel Reprocessing Plants," to 10 CFR Part 50, requires that nIeasures he established to assure materials control and control of special process, and that proper testing be performed.
Records," of Appendix A, "General Design Criteria for Nuclear Power Plants," to 10 CFR Part 50, requires that                                      The requirements for the specific examination structures, systems, and components important to safety                                methods mentioned in NB-2550 lack detail and need he designed, fabricated, erected, and tested to quality                                supplementing. In practice, examination procedures standards commensurate with the importance of the                                      which conform to these requirements have permitted safety functions to be performed. Appendix B, "Quality                                 defects of unacceptable size in tubular products to go Assurance Criteria for Nuclear Power Plants and Fuel                                   undetected because the defects were unfavorably Reprocessing Plants," to 10 CFR Part 50, requires that                                 oriented for the examination procedure applied.


This guide describes a method of implementing these requirements acceptable to the AEC Regulatory staff with regard to the nondestructive examination requirements for tubular products used for'mponents of the reactor coolant pressure boundary A other -safety-related systems. This guide applies to light-water-cooled reactors.
nIeasures he established to assure materials control and control of special process, and that proper testing be                                        To assure adequate control of quality for the performed. This guide describes a method of                                           products listed above, supplementary requirements have implementing these requirements acceptable to the AEC                                   been incorporated in this guide which include the Regulatory staff with regard to the nondestructive                                     identification of specific examination methods to be examination requirements for tubular products used for                                 used for each product form and additional requirements
    'mponents of the reactor coolant pressure boundary                                 for specific examination methods when appropriate.


The Advisory Committee on Reactor Safeguards has been consulted concerning this guide and has concurred in the regulatory postion.
A other -safety-related systems. This guide applies to light-water-cooled reactors. The Advisory Committee on                                 Ultrasonic Examination of Pipe and Tubing. Pipe and Reactor Safeguards has been consulted concerning this                                 tubing should be examined by the ultrasonic method guide and has concurred in the regulatory postion.                                     using the angle beam technique in both the axial and circumferential              directions.          The        ASME      Code


==B. DISCUSSION==
==B. DISCUSSION==
The requirements for nondestructive examination of wrought seamless tubular products used for components of nuclear power plants are specified in paragraph NB-2550 of Section 111, "Nuclear Power Plant Components," American Society of Mechanical Engineers (ASME) Boiler and Pressure Vessel Code.'These code requirements cover the examination of several product forms (pipe, tubing, flar~ges, fittings)under a single category, "Seamless and Welded (Without Filler Metal) Tubular Products and Fittings"'
requirements in NB-2550 supplemented by ASTM
without specifying the examination method to be used for each'Copies may be obtained from the American Society of Mechanical Engineers, United Engineering Center, 345 East 47th Street, New York, New York 10017.product form. Instead, the code simply states that the products shall be examined by one of several methods listed.The requirements for the specific examination methods mentioned in NB-2550 lack detail and need supplementing.
                                                                                        E-213, "Standard Method for Ultrasonic Inspection of The requirements for nondestructive examination of                             Metal        Pipe        and        Tubing          for      Longitudinal wrought seamless tubular products used for components                                 Discontinuities,"2 provide a suitable basis for detecting of nuclear power plants are specified in paragraph                                     axial defects. However, no consensus standard exists fbi NB-2550 of Section 111, "Nuclear Power Plant                                           the detection of circumferential defects (found in pipe Components,"                 American Society               of Mechanical             manufactured by processes such as extrusion, swaging.


In practice, examination procedures which conform to these requirements have permitted defects of unacceptable size in tubular products to go undetected because the defects were unfavorably oriented for the examination procedure applied.To assure adequate control of quality for the products listed above, supplementary requirements have been incorporated in this guide which include the identification of specific examination methods to be used for each product form and additional requirements for specific examination methods when appropriate.
Engineers (ASME) Boiler and Pressure Vessel Code.'                                      and tube reducing).                     Therefore, supplementary requirements for this purpose are included in this guide.


Ultrasonic Examination of Pipe and Tubing. Pipe and tubing should be examined by the ultrasonic method using the angle beam technique in both the axial and circumferential directions.
These code requirements cover the examination of several product forms (pipe, tubing, flar~ges, fittings)                                      The acceptance criteria for ultrasonic examination under a single category, "Seamless and Welded (Without                                are based on a comparison of ultrasonic indications Filler Metal) Tubular Products and Fittings"' without                                  reflected from discontinuities in the product with specifying the examination method to be used for each                                  indications from standard defects in a referenue
        'Copies may be obtained from the American Society of                                2 Copies may be obtained from American Society for Mechanical Engineers, United Engineering Center, 345 East 47th                        Testing    and     Materials,      1916      Race Street, Philadelphiai.


The ASME Code requirements in NB-2550 supplemented by ASTM E-213, "Standard Method for Ultrasonic Inspection of Metal Pipe and Tubing for Longitudinal Discontinuities,"2 provide a suitable basis for detecting axial defects. However, no consensus standard exists fbi the detection of circumferential defects (found in pipe manufactured by processes such as extrusion, swaging.and tube reducing).
Street, New York, New York 10017.                                                     Pennsylvania 19103.
Therefore, supplementary requirements for this purpose are included in this guide.The acceptance criteria for ultrasonic examination are based on a comparison of ultrasonic indications reflected from discontinuities in the product with indications from standard defects in a referenue 2 Copies may be obtained from American Society for Testing and Materials, 1916 Race Street, Philadelphiai.


Pennsylvania
USAEC REGULATORY GUIDES                                    Copies of published guides may be obtained by request indicating the divisions desired to the US. Atomic Energy Commission. Washington. D.C. 20545, Regulatory Guides are issued to describe and make available to the public            Attention: Director of Regulatory Standards. Comments and suggestions for methods acceptable to the AEC Regulatory staff of implementing specific parts of    improvemnnts in these guides ae encouraged and should be sent to the Secretary Tommission's regulations, to delineate techniques used by the staff in          of the Commission. U.S. Atomic Energy Commission. Washington. D.C. 20545.
1910


===3. USAEC REGULATORY ===
uing specific problems or postulated accidents, or to provide guidance to   Attention: Chief. Public Proceedings Staff.
GUIDES Copies of published guides may be obtained by request indicating the divisions desired to the US. Atomic Energy Commission.


Washington.
,,,;nts. Regulatory Guides are not substitutes for regulations and compliance
-;th them is not required. Methods and solutions different from those set out in      The guides are issued in the following ten broad divisions:
  the guides will be accepltable if they provide a basis for the findings requisite to the issuance or continuance of a permit or license by the Commission.                  1. Power Reactors                         


D.C. 20545, Regulatory Guides are issued to describe and make available to the public Attention:
===6. Products===
Director of Regulatory Standards.
                                                                                        2. Research and Test Reactors              
 
Comments and suggestions for methods acceptable to the AEC Regulatory staff of implementing specific parts of improvemnnts in these guides ae encouraged and should be sent to the Secretary Tommission's regulations, to delineate techniques used by the staff in of the Commission.
 
U.S. Atomic Energy Commission.
 
Washington.
 
D.C. 20545.uing specific problems or postulated accidents, or to provide guidance to Attention:
Chief. Public Proceedings Staff.,,,;nts. Regulatory Guides are not substitutes for regulations and compliance
-;th them is not required.
 
Methods and solutions different from those set out in The guides are issued in the following ten broad divisions:
the guides will be accepltable if they provide a basis for the findings requisite to the issuance or continuance of a permit or license by the Commission.
 
1. Power Reactors 6. Products 2. Research and Test Reactors  


===7. Transportation===
===7. Transportation===
3. Fuels and Materials Facilities  
                                                                                        3. Fuels and Materials Facilities           8. Occupational Health Published guides wilt be revised periodically, as appropriate. to accommodate         4. Environmental and Siting                 9. Antitrust Review comments and to reflect new information or experience.                                 . Materials and Plant Protect-or,         1
8. Occupational Health Published guides wilt be revised periodically, as appropriate.
 
to accommodate  
4. Environmental and Siting 9. Antitrust Review comments and to reflect new information or experience.
 
.Materials and Plant Protect-or, 10. General specimen.
 
The ASME Code requires that standard defects be axial notches on the inside and outside of the reference specimen, for which optimum resolution is developed tb, scanning in the transverse (circumferential)
tdieclittor.


l lowevet, transversw scanning is not ideal for resolving defects oriented in other directions.
===0. General===


As a consequence, when pipe or tubing is examined using transverse scanning and axial standard defects, defects of unacceptable size with unfavorable orientation may appear to be smaller than the reference standard and thus escape detection.
specimen. The ASME Code requires that standard                    should include methods that apply to the entire volume defects be axial notches on the inside and outside of the        of the product and should include techniques designed;
reference specimen, for which optimum resolution is              to locate all types of defects. In particular, procedure&!
developed tb, scanning in the transverse (circumferential)        for ultrasonic examination of pipe and tubing should tdieclittor. l lowevet, transversw scanning is not ideal for      provide a sensitivity that will detect randomly oriented resolving defects oriented in other directions. As a             defects that occasionally develop in pipe and tubing consequence, when pipe or tubing is examined using               manufactured by extrusion, swaging, or tube-reducing transverse scanning and axial standard defects, defects of       processes. To increase the probability of detecting such unacceptable size with unfavorable orientation may               defects, the examination requirements for tubular appear to be smaller than the reference standard and             productsl' specified in the ASME Boiler and Pressure thus escape detection. To adequately                  detect      Code, Section Ill, "Nuclear Power Plant Components,"'
circuinferentia! defects, it is necessary to scan in the          should be supplemented as follows:
axial directidn with equipment calibrated using circum icrent ial notches.                                        1. Required Examinations a. Wrought seamless and welded (without filler lFurther, scanning should be performed in both axial        metal) pipe and tubing should be examined over the and both circumferential directions for optimum                  entire volume of the material by the ultrasonic method detection of defects oriented in directions not normal to        in accordance with ASTM E-213, "Standard Method for the ' surface. This four-way scanning may be                      Ultrasonic Examination of Pipe and Tubing for accomplished by separate passes of the pipe through the          Longitudinal Discontinuities, and paragraphs C.2. and examination equipment in each direction (back and                C.3. below. Alternatively, eddy-current methods in forth) or by a single pass through equipment containing          accordance with NB-2554, Section 7II, ASME Code, may four complete and            independent channels of            be used provided the material has uniform magnetic instrumentation.                                                  properties and the product is limited to sizes and thicknesses for which meaningful examination results Eddy-Current Examination. Eddy-current examination                can be obtained by eddy-current methods.


To adequately detect circuinferentia!
may he used as an alternative to ultrasonic examination                  b. Tubular products used for Class 1 vessel nozzles for thin-walled pipe and tubing. However, this method              should be examined by the ultrasonic method in should be limited to materials with uniform magnetic              accordance with NB-2552 or the radiographic method in proper ties (variability in magnetic properties may result        accordance with NB-2553 over the entire volume +i from a variation in the degree of cold work in the material and by the magnetic particle methodL
defects, it is necessary to scan in the axial directidn with equipment calibrated using circum icrent ial notches.lFurther, scanning should be performed in both axial and both circumferential directions for optimum detection of defects oriented in directions not normal to the ' surface. This four-way scanning may be accomplished by separate passes of the pipe through the examination equipment in each direction (back and forth) or by a single pass through equipment containing four complete and independent channels of instrumentation.
material due to fabrication) and to pipe and tubing of accordance with NB-2555 or the liquid penetrant appropriate sizes and thicknesses. Since the limiting size        method      in !.-rnrint-A  w,,ith NB-55        oi'n 1 external and thickness may be affected by such variables as coil surfaces and all accessible internal surfaces.


Eddy-Current Examination.
design,      frequency,    material    properties,    and              c. Wrought seamless fittings (including flanges and instrunmentation, these limitations should be established by the ability to resolve standard notches on both                fittings machined from forgings and bars) should be outside and inside surface of the reference specimen.              examined by the ultrasonic method in accordance with NB-2552 or the radiographic method in accordance with Examination of Fittings. To the degree feasible, fittings          NB-2553 over the entire volume of the material for should be examined using a volumetric examination                  which meaningful examination results can be obtained.


Eddy-current examination may he used as an alternative to ultrasonic examination for thin-walled pipe and tubing. However, this method should be limited to materials with uniform magnetic proper ties (variability in magnetic properties may result from a variation in the degree of cold work in the material due to fabrication)  
method. Ultrasonic examination is preferred when                  Fittings or sections of fittings for which meaningful results cannot be obtained by these methods because of applicable,       but radiographic examination using irregular geometry or size should be examined by the appropriate techniques will also detect unacceptable              magnetic particle method in accordance with NB-2555 defects. The use of these techniques may be limited by or the liquid penetrant method in accordance with size, product configuration, or material condition NB-2556 on all external surfaces and all accessible (coarse-grained stainless steel) in which case a surface          internal surfaces.
and to pipe and tubing of appropriate sizes and thicknesses.


Since the limiting size and thickness may be affected by such variables as coil design, frequency, material properties, and instrunmentation, these limitations should be established by the ability to resolve standard notches on both outside and inside surface of the reference specimen.Examination of Fittings.
examination method (magnetic particle or liquid                          d. Welded tubular products (with filler metal penetrant) should be applied.                                    added) should be examined in accordance with NB-2560, Section IIl of the ASME Cod


To the degree feasible, fittings should be examined using a volumetric examination method. Ultrasonic examination is preferred when applicable, but radiographic examination using appropriate techniques will also detect unacceptable defects. The use of these techniques may be limited by size, product configuration, or material condition (coarse-grained stainless steel) in which case a surface examination method (magnetic particle or liquid penetrant)
====e. When the ====
should be applied.C. REGULATORY
POSITION Nondestructive examination applied to tubular products used for components of the reactor coolant pressure boundary and other safety-related systems which are designed for pressures in excess of 275 psig or temperatures in excess of 200 0 F should be capable of detecting unacceptable defects regardless of defect shape, orientation, or location in the product.Accordingly, to the degree practical, the examinations should include methods that apply to the entire volume of the product and should include techniques designed;to locate all types of defects. In particular, procedure&!
for ultrasonic examination of pipe and tubing should provide a sensitivity that will detect randomly oriented defects that occasionally develop in pipe and tubing manufactured by extrusion, swaging, or tube-reducing processes.


To increase the probability of detecting such defects, the examination requirements for tubular productsl'
==C. REGULATORY POSITION==
specified in the ASME Boiler and Pressure Code, Section Ill, "Nuclear Power Plant Components,"'
option for ultrasonic examination of finished welded pipe is invoked as permitted by NB-2560, the Nondestructive examination applied to tubular                examination should also meet the requirements of products used for components of the reactor coolant                ASTM E-213, "Standard Method for Ultrasonic pressure boundary and other safety-related systems Examination of Metal Pipe and Tubing," and paragraphs which are designed for pressures in excess of 275 psig or C.2. and C.3. below.
should be supplemented as follows: 1. Required Examinations a. Wrought seamless and welded (without filler metal) pipe and tubing should be examined over the entire volume of the material by the ultrasonic method in accordance with ASTM E-213, "Standard Method for Ultrasonic Examination of Pipe and Tubing for Longitudinal Discontinuities, and paragraphs C.2. and C.3. below. Alternatively, eddy-current methods in accordance with NB-2554, Section 7II, ASME Code, may be used provided the material has uniform magnetic properties and the product is limited to sizes and thicknesses for which meaningful examination results can be obtained by eddy-current methods.b. Tubular products used for Class 1 vessel nozzles should be examined by the ultrasonic method in accordance with NB-2552 or the radiographic method in accordance with NB-2553 over the entire volume +i material and by the magnetic particle methodL accordance with NB-2555 or the liquid penetrant method in !.-rnrint-A
w,,ith NB-55 oi'n 1 external surfaces and all accessible internal surfaces.c. Wrought seamless fittings (including flanges and fittings machined from forgings and bars) should be examined by the ultrasonic method in accordance with NB-2552 or the radiographic method in accordance with NB-2553 over the entire volume of the material for which meaningful examination results can be obtained.Fittings or sections of fittings for which meaningful results cannot be obtained by these methods because of irregular geometry or size should be examined by the magnetic particle method in accordance with NB-2555 or the liquid penetrant method in accordance with NB-2556 on all external surfaces and all accessible internal surfaces.d. Welded tubular products (with filler metal added) should be examined in accordance with NB-2560, Section IIl of the ASME Code. When the option for ultrasonic examination of finished welded pipe is invoked as permitted by NB-2560, the examination should also meet the requirements of ASTM E-213, "Standard Method for Ultrasonic Examination of Metal Pipe and Tubing," and paragraphs C.2. and C.3. below.3 Piping of 2 inch nominal pipe size or less which meet: design requirements of NB-3673, Section III, ASME cod, exempted from the examination requirements.


1.66-2
temperatures in excess of 200 0 F should be capable of detecting unacceptable defects regardless of defect                    3 Piping of 2 inch nominal pipe size or less which meet:
2. Ultrasonic Examination a. The procedure for ultrasonic examination should provide a sensitivity which will consistently detect defects that produce indications equal to or greater than the indications produced by standard defects in the reference specimen described in paragraph C.3. below and, insofar as practical, should be capable of detecting such defects regardless of orientation.
shape, orientation, or location in the product.                  design requirements of NB-3673, Section III, ASME cod, Accordingly, to the degree practical, the examinations            exempted from the examination requirements.


Products with defects that produce indications in excess of the reference standards are unacceptable unless the defects are eliminated or repaired.b. The techniques employed in ultrasonic examination of pipe should include angle beam scanning in both transverse and both longitudinal directions.
1.66-2


c. The rotation of the pipe and translation (feed helix) of the search unit assembly should be mai,,ained constant and should be such that 10MW/, volumetric coverage is assured in the longitudinal and r-knsverse directions.
2.    Ultrasonic Examination                                      d. The calibration procedure for ultrasonic a. The procedure for ultrasonic examination            examinations should be conducted in both transverse should provide a sensitivity which will consistently        and both longitudinal directions and at the speed that detect defects that produce indications equal to or          will be used for acceptance examination of the piping.


d. The calibration procedure for ultrasonic examinations should be conducted in both transverse and both longitudinal directions and at the speed that will be used for acceptance examination of the piping.3. Reference Specimen In addition to the axial notches or grooves required.by NB-2552, Section III of the ASME Code, the reference specimen used for ultrasonic examination of piping should also contain transverse notches extending circumferentially on the inner and outer surfaces.
greater than the indications produced by standard defects in the reference specimen described in paragraph    3.   Reference Specimen C.3. below and, insofar as practical, should be capable of        In addition to the axial notches or grooves required.


The transverse notches should have the same dimensional requirements as the axial notches (e.g., length of approximately I inch or less depending on the diameter, a width not to exceed 1/16 inch, and a depth not greater than the larger of 0.004 inch or 5 percent of the nominal wall thickness).  
detecting such defects regardless of orientation. Products  by NB-2552, Section III of the ASME Code, the with defects that produce indications in excess of the      reference specimen used for ultrasonic examination of reference standards are unacceptable unless the defects      piping should also contain transverse notches extending are eliminated or repaired.                                  circumferentially on the inner and outer surfaces. The b. The techniques employed in ultrasonic              transverse notches should have the same dimensional examination of pipe should include angle beam scanning      requirements as the axial notches (e.g., length of in both transverse and both longitudinal directions.        approximately I inch or less depending on the diameter, c. The rotation of the pipe and translation (feed    a width not to exceed 1/16 inch, and a depth not greater helix) of the search unit assembly should be mai,,ained    than the larger of 0.004 inch or 5 percent of the nominal constant and should be such that 10MW/, volumetric          wall thickness). All standard notches should be separated coverage is assured in the longitudinal and r-knsverse      sufficiently to preclude any interference or amplification directions.                                                of their respective indications.
All standard notches should be separated sufficiently to preclude any interference or amplification of their respective indications.


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Revision as of 21:22, 4 November 2019

Nondestructive Examination of Tubular Products
ML13064A108
Person / Time
Issue date: 10/31/1973
From:
US Atomic Energy Commission (AEC)
To:
References
RG-1.066
Download: ML13064A108 (3)


"uj October 1973 U.S. ATOMIC ENERGY COMMISSION

REGULATORY

DIRECTORATE OF REGULATORY STANDARDS

GUIDE

REGULATORY GUIDE 1.66 NONDESTRUCTIVE EXAMINATION OF TUBULAR PRODUCTS

A. INTRObUCTION product form. Instead, the code simply states that the products shall be examined by one of several methods General Design Criterion 1, "Quality Standards and listed.

Records," of Appendix A, "General Design Criteria for Nuclear Power Plants," to 10 CFR Part 50, requires that The requirements for the specific examination structures, systems, and components important to safety methods mentioned in NB-2550 lack detail and need he designed, fabricated, erected, and tested to quality supplementing. In practice, examination procedures standards commensurate with the importance of the which conform to these requirements have permitted safety functions to be performed. Appendix B, "Quality defects of unacceptable size in tubular products to go Assurance Criteria for Nuclear Power Plants and Fuel undetected because the defects were unfavorably Reprocessing Plants," to 10 CFR Part 50, requires that oriented for the examination procedure applied.

nIeasures he established to assure materials control and control of special process, and that proper testing be To assure adequate control of quality for the performed. This guide describes a method of products listed above, supplementary requirements have implementing these requirements acceptable to the AEC been incorporated in this guide which include the Regulatory staff with regard to the nondestructive identification of specific examination methods to be examination requirements for tubular products used for used for each product form and additional requirements

'mponents of the reactor coolant pressure boundary for specific examination methods when appropriate.

A other -safety-related systems. This guide applies to light-water-cooled reactors. The Advisory Committee on Ultrasonic Examination of Pipe and Tubing. Pipe and Reactor Safeguards has been consulted concerning this tubing should be examined by the ultrasonic method guide and has concurred in the regulatory postion. using the angle beam technique in both the axial and circumferential directions. The ASME Code

B. DISCUSSION

requirements in NB-2550 supplemented by ASTM

E-213, "Standard Method for Ultrasonic Inspection of The requirements for nondestructive examination of Metal Pipe and Tubing for Longitudinal wrought seamless tubular products used for components Discontinuities,"2 provide a suitable basis for detecting of nuclear power plants are specified in paragraph axial defects. However, no consensus standard exists fbi NB-2550 of Section 111, "Nuclear Power Plant the detection of circumferential defects (found in pipe Components," American Society of Mechanical manufactured by processes such as extrusion, swaging.

Engineers (ASME) Boiler and Pressure Vessel Code.' and tube reducing). Therefore, supplementary requirements for this purpose are included in this guide.

These code requirements cover the examination of several product forms (pipe, tubing, flar~ges, fittings) The acceptance criteria for ultrasonic examination under a single category, "Seamless and Welded (Without are based on a comparison of ultrasonic indications Filler Metal) Tubular Products and Fittings"' without reflected from discontinuities in the product with specifying the examination method to be used for each indications from standard defects in a referenue

'Copies may be obtained from the American Society of 2 Copies may be obtained from American Society for Mechanical Engineers, United Engineering Center, 345 East 47th Testing and Materials, 1916 Race Street, Philadelphiai.

Street, New York, New York 10017. Pennsylvania 19103.

USAEC REGULATORY GUIDES Copies of published guides may be obtained by request indicating the divisions desired to the US. Atomic Energy Commission. Washington. D.C. 20545, Regulatory Guides are issued to describe and make available to the public Attention: Director of Regulatory Standards. Comments and suggestions for methods acceptable to the AEC Regulatory staff of implementing specific parts of improvemnnts in these guides ae encouraged and should be sent to the Secretary Tommission's regulations, to delineate techniques used by the staff in of the Commission. U.S. Atomic Energy Commission. Washington. D.C. 20545.

uing specific problems or postulated accidents, or to provide guidance to Attention: Chief. Public Proceedings Staff.

,,,;nts. Regulatory Guides are not substitutes for regulations and compliance

-;th them is not required. Methods and solutions different from those set out in The guides are issued in the following ten broad divisions:

the guides will be accepltable if they provide a basis for the findings requisite to the issuance or continuance of a permit or license by the Commission. 1. Power Reactors

6. Products

2. Research and Test Reactors

7. Transportation

3. Fuels and Materials Facilities 8. Occupational Health Published guides wilt be revised periodically, as appropriate. to accommodate 4. Environmental and Siting 9. Antitrust Review comments and to reflect new information or experience. . Materials and Plant Protect-or, 1

0. General

specimen. The ASME Code requires that standard should include methods that apply to the entire volume defects be axial notches on the inside and outside of the of the product and should include techniques designed;

reference specimen, for which optimum resolution is to locate all types of defects. In particular, procedure&!

developed tb, scanning in the transverse (circumferential) for ultrasonic examination of pipe and tubing should tdieclittor. l lowevet, transversw scanning is not ideal for provide a sensitivity that will detect randomly oriented resolving defects oriented in other directions. As a defects that occasionally develop in pipe and tubing consequence, when pipe or tubing is examined using manufactured by extrusion, swaging, or tube-reducing transverse scanning and axial standard defects, defects of processes. To increase the probability of detecting such unacceptable size with unfavorable orientation may defects, the examination requirements for tubular appear to be smaller than the reference standard and productsl' specified in the ASME Boiler and Pressure thus escape detection. To adequately detect Code, Section Ill, "Nuclear Power Plant Components,"'

circuinferentia! defects, it is necessary to scan in the should be supplemented as follows:

axial directidn with equipment calibrated using circum icrent ial notches. 1. Required Examinations a. Wrought seamless and welded (without filler lFurther, scanning should be performed in both axial metal) pipe and tubing should be examined over the and both circumferential directions for optimum entire volume of the material by the ultrasonic method detection of defects oriented in directions not normal to in accordance with ASTM E-213, "Standard Method for the ' surface. This four-way scanning may be Ultrasonic Examination of Pipe and Tubing for accomplished by separate passes of the pipe through the Longitudinal Discontinuities, and paragraphs C.2. and examination equipment in each direction (back and C.3. below. Alternatively, eddy-current methods in forth) or by a single pass through equipment containing accordance with NB-2554, Section 7II, ASME Code, may four complete and independent channels of be used provided the material has uniform magnetic instrumentation. properties and the product is limited to sizes and thicknesses for which meaningful examination results Eddy-Current Examination. Eddy-current examination can be obtained by eddy-current methods.

may he used as an alternative to ultrasonic examination b. Tubular products used for Class 1 vessel nozzles for thin-walled pipe and tubing. However, this method should be examined by the ultrasonic method in should be limited to materials with uniform magnetic accordance with NB-2552 or the radiographic method in proper ties (variability in magnetic properties may result accordance with NB-2553 over the entire volume +i from a variation in the degree of cold work in the material and by the magnetic particle methodL

material due to fabrication) and to pipe and tubing of accordance with NB-2555 or the liquid penetrant appropriate sizes and thicknesses. Since the limiting size method in  !.-rnrint-A w,,ith NB-55 oi'n 1 external and thickness may be affected by such variables as coil surfaces and all accessible internal surfaces.

design, frequency, material properties, and c. Wrought seamless fittings (including flanges and instrunmentation, these limitations should be established by the ability to resolve standard notches on both fittings machined from forgings and bars) should be outside and inside surface of the reference specimen. examined by the ultrasonic method in accordance with NB-2552 or the radiographic method in accordance with Examination of Fittings. To the degree feasible, fittings NB-2553 over the entire volume of the material for should be examined using a volumetric examination which meaningful examination results can be obtained.

method. Ultrasonic examination is preferred when Fittings or sections of fittings for which meaningful results cannot be obtained by these methods because of applicable, but radiographic examination using irregular geometry or size should be examined by the appropriate techniques will also detect unacceptable magnetic particle method in accordance with NB-2555 defects. The use of these techniques may be limited by or the liquid penetrant method in accordance with size, product configuration, or material condition NB-2556 on all external surfaces and all accessible (coarse-grained stainless steel) in which case a surface internal surfaces.

examination method (magnetic particle or liquid d. Welded tubular products (with filler metal penetrant) should be applied. added) should be examined in accordance with NB-2560, Section IIl of the ASME Cod

e. When the

C. REGULATORY POSITION

option for ultrasonic examination of finished welded pipe is invoked as permitted by NB-2560, the Nondestructive examination applied to tubular examination should also meet the requirements of products used for components of the reactor coolant ASTM E-213, "Standard Method for Ultrasonic pressure boundary and other safety-related systems Examination of Metal Pipe and Tubing," and paragraphs which are designed for pressures in excess of 275 psig or C.2. and C.3. below.

temperatures in excess of 200 0 F should be capable of detecting unacceptable defects regardless of defect 3 Piping of 2 inch nominal pipe size or less which meet:

shape, orientation, or location in the product. design requirements of NB-3673,Section III, ASME cod, Accordingly, to the degree practical, the examinations exempted from the examination requirements.

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2. Ultrasonic Examination d. The calibration procedure for ultrasonic a. The procedure for ultrasonic examination examinations should be conducted in both transverse should provide a sensitivity which will consistently and both longitudinal directions and at the speed that detect defects that produce indications equal to or will be used for acceptance examination of the piping.

greater than the indications produced by standard defects in the reference specimen described in paragraph 3. Reference Specimen C.3. below and, insofar as practical, should be capable of In addition to the axial notches or grooves required.

detecting such defects regardless of orientation. Products by NB-2552,Section III of the ASME Code, the with defects that produce indications in excess of the reference specimen used for ultrasonic examination of reference standards are unacceptable unless the defects piping should also contain transverse notches extending are eliminated or repaired. circumferentially on the inner and outer surfaces. The b. The techniques employed in ultrasonic transverse notches should have the same dimensional examination of pipe should include angle beam scanning requirements as the axial notches (e.g., length of in both transverse and both longitudinal directions. approximately I inch or less depending on the diameter, c. The rotation of the pipe and translation (feed a width not to exceed 1/16 inch, and a depth not greater helix) of the search unit assembly should be mai,,ained than the larger of 0.004 inch or 5 percent of the nominal constant and should be such that 10MW/, volumetric wall thickness). All standard notches should be separated coverage is assured in the longitudinal and r-knsverse sufficiently to preclude any interference or amplification directions. of their respective indications.

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