Regulatory Guide 1.66

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

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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