ML003739242

Draft Regulatory Guide DG-1050 (Revision 12 to Regulatory Guide 1.147), Inservice Inspection Code Case Acceptability, ASME Section XI, Division 1

ML003739242
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Issue date:	05/31/1997
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DG-1050 RG-1.147, Rev 12
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U.S. NUCLEAR REGULATORY COMMISSION May 1997 OFFICE OF NUCLEAR REGULATORY RESEARCH Division 1 Draft DG-1050 DRAFT REGULATORY GUIDE

Contact:

E.O. Woolridge (301)415-6004 DRAFT REGULATORY GUIDE DG-1050 (Revision 12 to Regulatory Guide 1.147)

INSERVICE INSPECTION CODE CASE ACCEPTABILITY, ASME SECTION XI, DIVISION 1 A. INTRODUCTION Section 50.55a, "Codes and Standards," of 10 CFR Part 50, "Domestic Licensing of Production and Utilization Facilities," requires, in part, that each operating license for a boiling or pressurized water-cooled nuclear power facility and each construction permit for a utilization facility be subject to the conditions in paragraph (g), "Inservice Inspection Requirements," of § 50.55a. Paragraph (g) requires, in part, that Classes 1, 2, and 3 components and their supports meet the requirements of Section XI, "Rules for Inservice Inspection of Nuclear Power Plant Components,"' of the American Society of Mechanical Engineers (ASME) Boiler and Pressure Vessel Code or equivalent quality standards. Paragraph 50.55a(b), in part, references the latest editions and addenda in effect of Section XI of the Code and any supplementary requirements to that section of the Code. Footnote 6 to § 50.55a states that the use of specific Code Cases may be authorized by the Commission upon request pursuant to paragraph 50.55a(a)(3), which requires that proposed alternatives to the described requirements or portions thereof provide an acceptable level of quality and safety.

'Copies may be obtained from the American Society of Mechanical Engineers, United Engineering Center, 345 East 47th Street, New York, NY 10017.

This regulatory guide is being issued in draft form to involve the public in the early stages of the development of a regulatory position in this area. It has not received complete staff review and does not represent an official NRC staff position.

Public comments are being solicited on the draft guide (including any implementation schedule) and its associated regulatory analysis or value/impact statement, Comments should be accompanied by appropriate supporting data. Written comments may be submitted to the Rules and Directives Branch, DAS, Office of Administration, U.S. Nuclear Regulatory Commission, Washington, DC 20555. Copies of comments received may be examined at the NRC Public Document Room, 2120 L Street NW., Washington, DC. Comments will be most helpful if received by July 21, 1997.

Requests for single copies of active or draft regulatory guides (which may be reproduced) or for placement on an automatic distribution list for single copies of future draft guides in specific divisions should be made in writing to the U.S. Nuclear Regulatory Commission, Washington, DC 20555, Attention: Office of Information Resources Management, Distribution Services Section; or by fax to (301)415-2260.

General Design Criterion 1, "Quality Standards and Records," of Appendix A, "General Design Criteria for Nuclear Power Plants," to 10 CFR Part 50 requires, in part, that structures, systems, and components important to safety be designed, fabricated, erected, and tested to quality standards commensurate with the importance of the safety function to be performed. Where generally recognized codes and standards are used, Criterion 1 requires that they be identified and evaluated to determine their applicability, adequacy, and sufficiency and be supplemented or modified as necessary to ensure a quality product in keeping with the required safety function.

This regulatory guide lists those Section XI ASME Code Cases that are generally acceptable to the NRC staff for implementation in the inservice inspection of light-water-cooled nuclear power plants. The guide is being revised to update the NRC's position on new Code Cases, revised Code Cases, and annulled Code Cases since Revision 11 of the guide was issued in October 1994.

Regulatory guides are issued to describe and make available to the public such information as methods acceptable to the NRC staff for implementing specific parts of the Commission's regulations, techniques used by the staff in evaluating specific problems or postulated accidents, and guidance to applicants.

Regulatory guides are not substitutes for regulations, and compliance with regulatory guides is not required. Regulatory guides are issued in draft form for public comment to involve the public in the early stages of developing the regulatory positions. Draft regulatory guides have not received complete staff review and do not represent official NRC staff positions.

This regulatory guide contains no information collection activities and, therefore, is not subject to the requirements of the Paperwork Reduction Act of 1980 (44 U.S.C. 3501 et seq.).

B. DISCUSSION The ASME Boiler and Pressure Vessel Committee publishes a document entitled "Code Cases."' Generally, the individual Code Cases that make up this document explain the intent of Code rules or provide for alternative requirements under special circumstances.

Most Code Cases are eventually superseded by revision of the Code and then are annulled by action of the ASME. In such instances, the intent of the annulled Code Case becomes part of the revised Code, and therefore continued use of the Code Case intent is sanctioned under the rules of the Code. In other instances, the Code Case is annulled because it is no longer acceptable or there 2

is no further requirement for it. A Code Case that was approved for a particular situation and not for a generic application should be used only for the approved situation because annulment of such a Code Case could result in situations that would not meet Code requirements. The ASME considers the use of Code Cases to be optional for the user and not a mandatory requirement.

The Code Cases listed in this guide are limited to those cases applicable to Section XI of the Code.

All published Code Cases that are applicable to Section XI of the Code and were in effect on May 12, 1994,* were reviewed for inclusion in this guide. Code Cases that are not listed herein are either not endorsed or will require supple mentary provisions on an individual plant basis to attain endorsement status.

The endorsement of a Code Case by this guide constitutes acceptance of its technical position for applications not precluded by regulatory or other requirements or by the recommendations in this or other regulatory guides.

Contingent endorsement if applicable is indicated in Regulatory Position I for specific cases. However, it is the responsibility of the user to make certain that no regulatory requirements are violated and that there are no conflicts with other recommended limitations resulting from Code Case usage.

Acceptance or endorsement by the NRC staff applies only to those Code Cases or Code Case revisions with the date of ASME approval as shown in the Regulatory Position of this guide. Earlier or later revisions of a Code Case are not endorsed by this guide. New Code Cases will require evaluation by the NRC staff to determine whether they qualify for inclusion in the approved list. Because of the continuing change in the status of Code Cases, it is planned that this guide will require periodic updating to accommodate new Code Cases and any revision of existing Code Cases.

"Lines indicate substantive changes from Revision 11.

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C. REGULATORY POSITION

1. ACCEPTABLE CODE CASES The Section XI ASME Code Cases 2 listed below (by number, date of ASME approval, 3 and title) are acceptable to the NRC staff for application in the inservice inspection of components and their supports for water-cooled nuclear power plants. Their use is acceptable within the limitations stated in the "Inquiry" and "Reply" sections of each individual Code Case, within the limitations of such NRC or other requirements as may exist, and within the additional limitations recommended by the NRC staff and given with the individual Code Case in the list.

1705-1 03-01-76 Ultrasonic Examination -- Calibration Block N-98 11-20-78 Tolerances,Section XI 01-21-82 12-05-84 12-05-87 12-03-90 I 08-09-93 N-113-1 12-13-82 Basic Calibration Block for Ultrasonic Examination of 02-14-85 Welds 10 in. to 14 in. Thick,Section XI, Division 1 02-14-88 12-03-90 I 08-09-93 N-21 14 07-13-81 Recalibration of Ultrasonic Equipment Upon Change of 07-13-84 Personnel,Section XI, Division 1 05-07-87 04-30-90 I 04-30-93 N-235 01-08-79 Ultrasonic Calibration Checks per Section V, Section 04-02-82 XI, Division 1 02-14-85 02-14-88 12-03-90 I 08-09-93 2

A numerical listing of the Code Cases appears in the Appendix.

'When more than one date is given, the earlier date is that on which the Code Case was approved by the ASME, and the later date (or dates) is that on which the Code Case was reaffirmed by the ASME.

"The Code Case was annulled on 3-20-81 (ASME mandatory annulment date). It was reinstated on 7-13-81.

Because there was no change in the Code Case, the NRC considers that the Case was in effect during the period 3-20-81 through 7-13-81.

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N-236-1 09-05-85 Repair and Replacement of Class MC Vessels,Section XI, 09-05-88 Division 1 08-14-91 N-307-1 12-05-84 Revised Ultrasonic Examination Volume for Class I 12-05-87 Bolting, Table IWB-2500-1, Examination Category B-G-1, 12-03-90 When the Examinations Are Conducted from the Center 08-09-93 Drilled Hole,Section XI, Division 1 N-311 05-11-81 Alternative Examination of Outlet Nozzle on Secondary 04-05-84 Side of Steam Generators,Section XI, Division I 05-07-87 04-30-90 02-12-93 [

Code Case N-311 is acceptable subject to the following condition in addition to those conditions specified in the Code Case: The applicant should indicate in the Safety Analysis Report that the stress analysis of the nozzle inside-corner region meets the Code Case stipulations for the state of stress in this region.

N-335-1 06-20-85 Rules for Ultrasonic Examination of Similar and 06-20-88 Dissimilar Metal Piping Welds,Section XI, Division I 05-13-91 05-11-94 I N-355 07-16-82 Calibration Block for Angle Beam Ultrasonic 02-14-85 Examination of Large Fittings in Accordance with 02-14-88 Appendix Ill- 3410,Section XI, Division 1 12-03-90 08-09-93 N-356 07-01-885 Certification Period for Level III NDE Personnel, 10-23-88 Section XI, Division 1, 2 and 3 08-05-94 N-389-1 12-09-93 Alternative Rules for Repairs, Replacements, or Modifications,Section XI, Division I N-401-1 05-04-88 Eddy Current Examination,Section XI, Division I 05-13-91 05-11-94 N-402-1 03-14-91 Eddy Current Calibration Standards,Section XI, 05-11-94 Division 1 f N-408-3 08-09-93 Alternative Rules for Examination of Class 2 Piping,Section XI, Division I Code Case N-408-3 is acceptable subject to the following condition in addition to those conditions specified in the Code Case: The applicant for an operating license should define the Class 2 piping subject to volumetric 5July 1, 1988, is the date that conditions of the Code Case were acceptable to the NRC.

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and surface examination in the Preservice Inspection for determination of acceptability by the NRC staff. L N-409-3 04-30-93 Procedure and Personnel Qualification Requirements for Ultrasonic Detection and Sizing of Flaws in Piping Welds,Section XI, Division I Code Case N-409-3 is acceptable subject to the following condition in addi tion to those conditions specified in the Code Case: The applicant should give prior notification to the NRC of the intention to use the Code Case.

N-415 09-05-85 Alternative Rules for Testing Pressure Relief Devices, 09-05-88 Section XI, Division 1 08-14-91 N-416-1 02-15-94 Alternative Pressure Test Requirements for Welded Repairs or Installation of Replacement Items by Welding, Class 1, 2, and 3,Section XI, Division I Code Case N-416-1 is acceptable subject to the following condition in addition to those conditions specified in the Code Case. Additional surface examinations should be performed on the root (pass) layer of butt and socket welds of the pressure retaining boundary of Class 3 components when the surface examination method is used in accordance with Section III.

N-427 12-05-85 Code Cases in Inspection Plans,Section XI, Division 1 12-05-88 12-16-91 Code Case N-427 is acceptable subject to the following condition in addition to those conditions specified in the Code Case. The sentence under (b)(1) should be replaced with the following: Code Cases that were superseded with revised Code Cases and had been approved for use in accordance with (a) may continue to be used.

N-429-1 02-23-87 Alternative Rules for Ultrasonic Instrument Calibration, 03-05-90 Section XI, Division I 07-27-92 N-432 02-20-86 Repair Welding Using Automatic or Machine Gas 02-20-89 Tungsten-Arc Welding (GTAW) Temperbead Technique, 12-16-91 Section XI, Division I N-435-1 07-30-86 Alternative Examination Requirements for Vessels with 07-30-89 Wall Thickness 2 in. or less,Section XI, Division 1 07-30-92 N-437 07-30-86 Use of Digital Readout and Digital Measurement Devices 07-30-89 for Performing Pressure Tests,Section XI, Division 1 07-30-92 N-448 07-27-87 Qualification of VT-2 and VT-3 Visual Examination Per 04-30-90 sonnel,Section XI, Division I 04-30-93 6

N-449 07-27-87 Qualification of VT-4 Visual Examination Personnel, 04-30-90 Section XI, Division 1 04-30-93 N-457 12-07-87 Qualification Specimen Notch Location for Ultrasonic 12-03-90 Examination of Bolts and Studs,Section XI, Division 1 08-09-93 N-458 08-14-90 Magnetic Particle Examination of Coated Materials, 04-30-93 Section XI, Division I N-460 07-27-88 Alternative Examination Coverage for Class I and Class 05-13-91 2 Welds,Section XI, Division 1 05-11-94 N-461 11-30-88 Alternative Rules for Piping Calibration Block 08-14-91 Thickness,Section XI, Division 1 Code Case N-461 is acceptable subject to the following condition in addition to those conditions specified in the Code Case: Thickness measurements and weld joint contour of the pipe/component must be known and used by the inspector who conducts the UT examination.

N-463-1 03-05-90 Evaluation Procedures and Acceptance Criteria for Flaws in Class 1 Ferritic Piping That Exceed the Acceptance Standards of IWB-3514.2,Section XI, Division I N-465 11-30-88 Alternative Rules for Pump Testing,Section XI, 08-14-91 Division 1 N-471 04-30-90 Accoustic Emission for Successive Inspections, Section 02-12-93 XI, Division 1 Code Case N-471 is acceptable subject to the following conditions in addition to those specified in the Code Case: The first successive examination required by IWB-2420 or IWC-2420 shall be performed. The owner shall evaluate the results of the on-line acoustic emission monitoring to confirm that the conclusions from the acoustic emission data represent the condition of the flaw indication as estimated from the first successive ISI Examination and the data can be correlated with the known plant operating environment.

N-472 03-08-89 Use of Digital Readout and Digital Measurement Devices 12-16-91 for Performing Pump Vibration Testing,Section XI, Division 1 N-473 03-08-89 Alternative Rules for Valve Testing,Section XI, 12-16-91 Division 1 N-479-1 12-03-90 Boiling Water Reactor (BWR) Main Steam Hydrostatic 12-09-93 Test,Section XI, Division I N-481 03-05-90 Alternate Examination Requirements for Cast Austeni 11-25-92 tic Pump Casings,Section XI, Division 1 7

N-485-1 08-14-91 Eddy Current Examination of Coated Ferritic Surfaces as an Alternative to Surface Examination,Section XI, Division I N-489 08-14-90 Alternative Rules for Level III NDE Qualification 04-30-93 Examinations,Section XI, Divisions 1, 2, and 3 N-490-1 05-13-91 Alternative Vision Test Requirements for Nondestructive 05-11-94 Examiners,Section XI, Divisions 1, 2, and 3 N-491-1 04-30-93 Alternative Rules for Examination of Class 1, 2, 3 and MC Component Supports of Light-Water Cooled Power Plants,Section XI, Division 1 N-494-2 12-09-93 Pipe Specific Evaluation Procedures and Acceptance Criteria for Flaws in Class 1 Ferritic Piping that Exceeds the Acceptance Standards of IWB-3514.2,Section XI, Division I N-495 12-03-90 Hydrostatic Testing of Relief Valves,Section XI, 12-09-93 Division 1 N-496-1 05-11-94 Helical Coil Threaded Inserts,Section XI, Division I N-498-1 05-11-94 Alternative Rules for 10-Year Hydrostatic Pressure Testing for Class 1 and 2 Systems,Section XI, Division I N-503 02-05-92 Limited Certification of Nondestructive Examination Personnel,Section XI, Division 1 N-504-1 08-09-93 Alternative Rules for Repair of Class 1, 2, and 3 Austenitic Stainless Steel Piping,Section XI, Division I N-509 11-25-92 Alternative Rules for the Selection and Examination of Class 1, 2, and 3 Integrally Welded Attachments,Section XI, Division 1 Code Case N-509 is acceptable subject to the following condition in addition to those conditions specified in the Code Case: A minimum 10%

sample of integrally welded attachments for each item in each code class per interval should be examined.

N-512 02-12-93 Assessment of Reactor Vessels With Low Upper Shelf Charpy Impact Energy Levels,Section XI, Division I N-514 02-12-93 Low Temperature Overpressure Protection,Section XI, Division 1 N-515 02-12-93 Class I Mechanical Joint Pressure Tests,Section XI, Division I 8

N-516 08-09-93 Underwater Welding,Section XI, Division 1 Code Case N-516 is acceptable subject to the following condition in addition to those conditions specified in the Code Case. When welding is to be performed on high neutron fluence Class 1 material, then a mockup, using material with similar fluence levels, should be welded to verify that adequate crack prevention measures were used.

N-521 08-09-93 Alternative Rules for Deferral of Inspections of Nozzle to-Vessel Welds, Inside Radius Sections, and Nozzle-to Safe End Welds of a Pressurized Water Reactor (PWR)

Vessel,Section XI, Division 1 Code Case N-521 is acceptable subject to the following condition in addition to those conditions specified in the Code Case. When deferring nozzle inspections to the end of the interval, there should be no more than ten years between inspections, except where the length of a 10 year interval is adjusted in accordance with IWA-2430.

N-522 12-09-93 Pressure Testing of Containment Penetration Piping,Section XI, Division 1 Code Case N-522 is acceptable subject to the following condition in addition to those conditions specified in the Code Case. The test should be conducted at the peak calculated containment pressure and the test procedure should permit the detection and location of through-wall leakage in containment isolation valves (CIVs) and pipe segments between the CIVs.

N-524 08-09-93 Alternative Examination Requirements for Longitudinal Welds in Class I and 2 Piping,Section XI, Division 1 N-537 03-14-95 Location of Ultrasonic Depth-Sizing Flaws,Section XI, Division I N-541 06-09-95 Alternative Requirements for Performance Demonstration in Accordance with Appendix VIII, Supplements 4 and 6,Section XI, Division 1

2. ANNULLED CODE CASES Code Cases that were endorsed by the NRC in a prior version of this guide and were later annulled by action of the ASME should be considered as deleted from the list of acceptable Code Cases as of the date of the ASME action that 9

approved the annulment. Such Code Cases that were annulled on or after November 1, 1978, are listed below by number, effective dates, 6 and title.

1551 11-06-72 Inservice Inspection of Welds on Nuclear Components, (N-34) 11-20-78 Section XI 11-20-81 1646 08-12-74 Partial Postponement of Category B-C Examination for (N-72) 11-20-78 Class 1 Components,Section XI 01-01-81 1647 08-12-74 Partial Postponement of Category B-D Examination for (N-73) 11-20-78 Class 1 Components,Section XI 01-01-81 1730 11-03-75 Acceptance Standards for Class 2 and 3 Components, (N-112) 07-01-79 Section XI, Division 1 1738 12-22-75 Examination -- Acceptance Standards for Surface (N-118 11-20-78 Indications in Cladding,Section XI 01-21-82 01-21-85 01-21-88 12-03-90 Code Case 1738 (N-118) was acceptable subject to the following condition in addition to those conditions specified in the Code Case. The last sentence of the "Reply" should be replaced with the following: The provisions of this Code Case may not be applied for the examination of clad surfaces of nozzles, including the inner surface of the nozzle-to-vessel insert welds.

1804 01-14-77 Minimum Section Thickness Requirements for Repair of (N-167 01-14-80 Nozzles,Section XI, Division 1 N-210 03-20-78 Exemption to Hydrostatic Tests After Repairs, Section 03-20-81 XI, Division I Code Case N-210 was acceptable subject to the following condition in addition to those conditions specified in the Code Case. Paragraph (3) of the "Reply" should be replaced with the following: Repairs to piping, pumps, and valves where the depth of the repaired cavity does not exceed 25 percent of the wall thickness.

N-211 03-20-78 Recalibration of Ultrasonic Equipment Upon Change 03-20-81 of Personnel,Section XI, Division I L

6 Earlier date -- date Code Case was approved by ASME; later date -- date Code Case was annulled. Where more than two dates appear, the last date is the date that the Code Case was annulled. The middle date (or dates) was the date of reaffirmation of the Code Case.

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N-216 03-10-78 Alternative Rules for Reactor Vessel Closure Stud 07-13-81 Examination,Section XI, Division 1 07-13-84 05-07-87 05-07-90 N-234 01-08-79 Time Between Ultrasonic Calibration Checks, Section 01-21-82 XI, Division 1 12-05-84 12-05-87 12-03-90 N-252 11-19-79 Low Energy Capacitive Discharge Welding Method for 07-16-82 Temporary or Permanent Attachments to Components and Supports,Section III, Division 1, and XI Code Case N-252 was acceptable subject to the following condition in addition to those conditions specified in the Code Case: The applicant should indicate in the Safety Analysis Report the application, the material, and the thickness of the material to which the strain gage or thermocouple will be attached by CD welding.

N-278 03-17-80 Alternative Ultrasonic Calibration Block Configuration 03-17-837 1-3131 and T-434.3,Section XI, Division 1 05-25-837 02-19-86 02-19-89 02-19-92 Code Case N-278 was acceptable subject to the following conditions in addition to those conditions specified in the Code Case: When a universal calibration block is used and some or all of the reference holes are larger than the reflector holes at comparable depths recommended by Article IV,Section V, 1980 edition of the ASME Code, a correction factor should be used to adjust the DAC level to compensate for the larger reflector holes.

Also, if the reactor pressure vessel was previously examined by using a conventional block, a ratio between the DAC curves obtained from the two blocks should be noted (for reference) with the significant indication data.

N-288 08-25-80 Hydrostatic Test Requirements for Class 1 and Class 2 05-25-83 Components,Section XI, Division I N-306 01-15-81 Calibration Block Material Selection, Appendix 1, 04-05-84 1-3121,Section XI, Division 1 05-07-87 05-07-90

'Code Case N-278 was inadvertently allowed to expire because of an ASME administrative error on 3-17-83, its mandatory annulment date. The Code Case, without any technical changes, was reinstated on 5-25-93. Because of these circumstances, the Code Case is considered to be in effect during that period of time.

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N-308 09-30-81 Documentation of Repairs and Replacements of Components 09-30-84 in Nuclear Power Plants,Section XI, Division 1 09-30-87 04-30-90 09-30-90 N-343 04-02-82 Alternative Scope of Examination of Attachment Welds 02-14-85 for Examination Categories B-H, B-K-i, and C-C, 02-14-88 Section XI, Division 1 12-03-90 N-375-2 04-05-84 Rules for Ultrasonic Examination of Bolts and Studs, 05-07-87 Section XI, Division 1 05-07-90 N-406 04-05-84 Alternative Rules for Replacement, Section XI, 05-07-87 Division 1 05-07-90 N-419 07-18-85 Extent of VT-I Examinations, Category B-G-I of Table 07-18-88 IWB-2500-1,Section XI, Division 1 05-13-91 05-13-94 N-424 07-18-85 Qualification of Visual Examination Personnel, Section 07-18-88 XI, Division I N-426 07-18-85 Extent of VT-1 Examinations, Category B-G-2 of Table 07-18-88 IWB-2500-1,Section XI, Division 1 05-13-91 05-13-94 N-436-1 12-07-87 Alternative Methods for Evaluation of Flaws in 12-03-90 Austenitic Piping,Section XI, Division 1 N-444 8 12-07-87 Preparation of Inspection Plans,Section XI, 12-03-90 Division I N-445 05-07-87 Use of Later Editions of SNT-TC-1A for Qualification 05-07-90 of Nondestructive Examination Personnel,Section XI, Division 1, 2, and 3 N-446 05-07-87 Recertification of Visual Examination Personnel, 05-07-90 Section XI, Division I "Valve stroke times may be documented outside of the IST program. However, if included within the IST program and it becomes necessary to revise the maximum stroke time required by "Supplement 4-Content of IWV Valve Test Tables," it is not necessary to submit a revised IST program to the NRC solely to document a revision in valve stroke time.

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3. REVISED CODE CASES Code Cases that were endorsed by the NRC in a prior version of this guide and were superseded by revised Code Cases on or after November 1, 1978, should be considered as not endorsed as of the date of the ASME action that approved the revised version of the Code Cases. These Code Cases that are no longer endorsed are listed in the following by number, effective dates 9 and title.

1731 11-03-75 Basic Calibration Block for Ultrasonic Examination (N-113) 11-20-78 of Welds 10 in. to 13 in. Thick,Section XI, 01-21-82 Division 1 12-13-82 N-236 01-08-79 Repair and Replacement of Class MC Vessels, Section 01-21-82 XI, Division 1 12-05-84 09-05-85 Code Case N-236 was acceptable subject to the following conditions in addition to those conditions specified in the Code Case: a. In paragraph 1.0(a), second sentence, the phrase, "while the plant is not in service,"

refers to a refueling outage. b. In paragraph 1.0(a), third sentence, the phrase, "the next scheduled plant outage," refers to the next scheduled refueling outage.

For clarification, Repair and Replacement of Class MC Vessels means Repair and Replacement of Class MC Vessels and Components (systems).

Acceptance of this Code Case in no way infers NRC approval to violate the technical specification or any NRC requirements with regard to breach of containment during repair and replacement procedures while the plant is in operation.

Where a numbered Code paragraph is not identified by a particular edition of the Code, the Code in effect at the time of the ASME meeting (11-3-78) that approved the Code Case should be governing.

N-307 01-15-81 Revised Ultrasonic Examination Volume for Class 1 04-05-84 Bolting, Examination Category B-G-1, When the 12-05-84 Examinations Are Conducted from the Center-Drilled Hole,Section XI, Division 1 N-335 04-02-82 Rules for Ultrasonic Examination of Similar and 02-14-85 Dissimilar Metal Piping Welds,Section XI, Division 1 06-20-85 9Earlier date-date Code Case was approved by ASME; later date-date revision of Code Case was approved by ASME. Where more than two dates appear, the last date is the date on which the Code Case was revised. The middle date (or dates) was the date of reaffirmation of the Code Case.

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N-3751° 02-14-83 Rules for Ultrasonic Examination of Bolts and 04-14-83 Studs,Section XI, Division 1 N-375-1 04-14-83 Rules for Ultrasonic Examination of Bolts and 04-05-84 Studs,Section XI, Division I N-389 07-25-83 Alternative Rules for Repairs, Replacements, or 05-14-86 Modifications,Section XI, Division I 05-14-89 02-05-92 12-09-93 Code Case N-389 was acceptable subject to the following condition in addition to those conditions specified in the Code Case: The applicant should submit for approval the appropriate edition and addenda of the Code that is to be used for the repair, replacement, or modification before start of the work.

N-401 02-20-84 Eddy Current Examination, Section XI, Division I 02-23-87 05-04-88 N-402 02-20-84 Eddy Current Calibration Standard Material, 02-23-87 Section XI, Division 1 03-05-90 03-14-91 N-408 07-12-84 Alternative Rules for Examination of Class 2 Piping, 05-07-87 Section XI, Division 1 03-08-89 N-408-1 03-08-89 Alternative Rules for Examination of Class 2 Piping, 07-24-89 Section XI, Division I Code Case N-408-1 was acceptable subject to the following condition in addition to those conditions specified in the Code Case: The applicant for an operating license should define the Class 2 piping subject to volumetric and surface examination in the Preservice Inspection for determination of acceptability by the NRC staff.

N-408-2 07-24-89 Alternative Rules for Examination of Class 2 Piping, 07-24-92 Section XI, Division I 08-09-93 Code Case N-408-2 was acceptable subject to the following condition in addition to those conditions specified in the Code Case: The applicant for an operating license should define the Class 2 piping subject to volumetric and surface examination in the Preservice Inspection for determination of acceptability by NRC staff.

10 Code Case N-375 was not listed prior to Revision 3 of this regulatory guide.

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N-409 12-05-84 Procedure and Personnel Qualification for Ultrasonic 12-07-87 Detection and Sizing of Intergranular Stress Corrosion Cracking in Austenitic Piping Welds,Section XI, Division 1 N-409-1 12-07-87 Procedure and Personnel Qualification Requirements for 07-27-88 Ultrasonic Detection and Sizing of Flaws in Piping Welds,Section XI, Division 1 Code Case N-409-1 was acceptable subject to the following condition addition to those conditions specified in the Code Case: The in should give prior notification to the NRC of the intention to applicant use the Code Case.

N-409-2 07-27-88 Procedure and Personnel Qualification Requirements 05-13-91 for Ultrasonic Detection and Sizing of Flaws in Piping 04-30-93 Welds,Section XI, Division 1 Code Case N-409-2 was acceptable subject to the following condition addition to those conditions specified in the Code Case: The in should give prior notification to the NRC of the intention to applicant use the Code Case.

N-416 12-05-85 Alternative Rules for Hydrostatic Testing of Repair or 12-05-87 Replacement of Class 2 Piping,Section XI, Division 1 12-03-90 02-15-94 N-429 12-05-85 Alternative Rules for Ultrasonic Instrument 02-23-87 Calibration,Section XI, Division 1 N-435 05-14-86 Alternative Examination Requirements for Vessels with 07-30-86 Wall Thickness 2 in. or Less,Section XI, Division I N-436 05-14-86 Alternative Methods for Evaluation of Flaws in Aus 12-07-87 tenitic Piping,Section XI, Division I N-463 11-30-88 Evaluation Procedures and Acceptance Criteria for Flaws 03-05-90 in Class I Ferritic Piping That Exceed the Acceptance Standards of IWB-3514.2,Section XI, Division I N-479 07-24-89 Boiling Water Reactor (BWR) Main Steam Hydrostatic 12-03-90 Test,Section XI, Division I N-485 04-30-90 Eddy Current Examination of Coated Ferritic Surfaces 08-14-91 as an Alternative to Surface Examination,Section XI, Division I N-490 08-14-90 Alternative Vision Test Requirements for Nondestruc 05-13-91 tive Examiners,Section XI, Divisions 1, 2, and 3 N-491 03-14-91 Alternative Rules for Examination of Class 1, 2, 3 04-30-93 and MC Component Supports of Light-Water Cooled Power Plants,Section XI, Division 1 15

N-494 12-03-90 Pipe Specific Evaluation Procedures and Acceptance 07-17-92 Criteria for Flaws in Class 1 Ferritic Piping that Exceeds the Acceptance Standards of IWB-3514.2,Section XI, Division 1 N-494-1 07-27-92 Pipe Specific Evaluation Procedures and Acceptance 12-09-93 Criteria for Flaws in Class 1 Ferritic Piping that Exceeds the Acceptance Standards of IWB-3514.2,Section XI, Division 1 N-496 03-14-91 Helical Coil Threaded Inserts, Section XI, Division 1 02-15-94 05-11-94 N-498"1 05-13-91 Alternative Rules for 10-Year Hydrostatic Pressure 05-11-94 Testing for Class I and 2 Systems,Section XI, Division I N-504 4-30-92 Alternative Rules for Repair of Class 1, 2, and 3 8-09-93 Austenitic Stainless Steel Piping,Section XI, Division 1

4. UNACCEPTABLE CODE CASES Code Cases that are not on the approved list of this guide (Regulatory Position 1) or other regulatory guides, or for which authorization by the Commission has not been granted, are not acceptable on a generic basis.

D. IMPLEMENTATION The purpose of this section is to provide information to applicants regarding the use of this regulatory guide.

its This draft guide has been released to encourage public participation in development. The final version of this Revision 31, reflecting public comments, will address the ASME Code Cases as follows.

1. Except for those Code Cases that have been annulled by action of the ASME, the NRC staff will find the Code Cases listed in the final version of this regulatory guide under Regulatory Position 1 acceptable for appropriate use. Other Code Cases may be considered for use in accordance with footnote 6 of the Codes and Standards rule, § 50.55a of 10 CFR Part 50.

"Code Case N-498 was approved for use by ASME on 5-13-91. It was included in Revision 9 of this guide because of an urgent need for the case.

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2. Components ordered to a specific version of a Code Case need not be changed because a subsequent revision of the Code Case is listed as the approved version in this guide.

3. Code Cases to be applied during an inspection interval or Code Cases for a preservice inspection that were previously approved for use may continue to be used even though the Code Case has been subsequently annulled.

4. Code Cases on the approved list may be applied to procedures for an inspection interval and procedures for the inservice inspection that were established prior to the effective date of the Code Case within the limits specified in the Code Case and applicable regulations or recommended in other regulatory guides.

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APPENDIX NUMERICAL LISTING OF CODE CASES N-98 (1705-1) N-432 N-491-1 N-113-1 N-435-1 N-494-2 N-211 N-437 N-495 N-235 N-448 N-496-1 N-236-1 N-449 N-498-1 N-307-1 N-457 N-503 N-311 N-458 N-504-1 N-335-1 N-460 N-509 N-355 N-461 N-512 N-356 N-463-1 N-514 N-389-1 N-465 N-515 N-401-1 N-471 N-516 N-402-1 N-472 N-521 N-408-3 N-473 N-522 N-409-3 N-479-1 N-524 N-415 N-481 N-537 N-416-1 N-485-1 N-541 N-427 N-489 N-429-1 N-490-1 18

VALUE/IMPACT STATEMENT

1. PROPOSED ACTION 1.1 Description Regulatory Guide 1.147, "Inservice Inspection Code Case Acceptability, ASME Section XI, Division I," is being revised to reflect the current NRC acceptance of the Code Cases of the American Society of Mechanical Engineers (ASME). Code Cases are periodically published by ASME to either clarify the intent of existing code rules or to provide, when the need is urgent, rules for materials or construction not covered by existing Code Rules. These Code Cases require approval by the ASME's Main Committee and the Board of Nuclear Codes and Standards prior to their acceptance by the ASME. Use of these nonmandatory Code Cases is subject to general acceptance by the NRC staff, and the accepted Code Cases are then incorporated into Regulatory Guide 1.147. Pursuant to 10 CFR 50.55a, other Code Cases may be used provided specific NRC authorization is obtained on a case-by-case basis.

1.2 Rationale for Conditional Acceptances The NRC would impose a conditional acceptance on the following Code Cases.

The code cases, with the rationale for their conditional acceptances and with assessments of their impacts on industry, are given here.

1.2.1 Code Case N-416-1, Alternative Pressure Test Requirements for Welded Repairs or Installation of Replacement Items by Welding, Class 1, 2, and 3 Code Case N-416-1 is acceptable subject to the following condition in addition to those conditions specified in the Code Case. Additional surface examinations should be performed on the root (pass) layer of butt and socket welds of the pressure retaining boundary of Class 3 components when the surface examination method is used in accordance with Section III.

The conditional acceptance would be imposed because, when considering the nature of NDE requirements for Code Class 3 components, the staff does not believe that eliminating the hydrostatic pressure testing and only performing 19

system pressure testing is an acceptable alternative to the hydrostatic testing unless additional surface examinations are performed on the root pass layer of butt and socket welds on the pressure-retaining boundary of Class 3 components when the surface examination method is used in accordance with Section III. The Chairman of Pressure Testing Subgroup of ASME was informed that the NRC would not accept the Code Case without the exception in the endorsement. However, the ASME passed the Case without the changes requested by the NRC. The impact of the conditional acceptance to this Code Case would be minimal in relation to the ASME Code and to the original Code Case that called for hydrostatic testing.

1.2.2 Code Case N-509, Alternative Rules for the Selection and Examination of Class 1, 2, and 3 Integrally Welded Attachments Code Case N-509 is acceptable subject to the following condition in addition to those conditions specified in the Code Case: A minimum 10%

sample of integrally welded attachments for each item in each code class per interval should be examined.

The conditional acceptance would be imposed on Code Case N-509 because there is an ambiguity in the notes of the examination tables that could reduce the examination sample to an insignificant amount, or to no integral attachments at all. The staff believes that Code Case N-509 should be augmented to ensure that this does not occur. Considering that most of the Code examination requirements are based on sampling to ensure the detection of service-induced degradations, extending the sampling philosophy to the integral attachment welds will provide an equivalent level of quality and safety for those welds. NRC considers that this conditional acceptance poses no significant impact on industry as this condition conveys the intent of this Code Case.

1.2.3 Code Case N-516, Underwater Welding Code Case N-516 is acceptable subject to the following condition in addition to those conditions specified in the Code Case. When welding is to be performed on high neutron fluence Class I material, then a mockup, using material with similar fluence levels, should be welded to verify that adequate crack prevention measures were used.

The conditional acceptance would be imposed because the Code Case fails to recognize the condition of the material to be welded. Material that is highly irradiated could react quite differently from annealed or mildly irradiated material. The material could be quite brittle and not possess adequate crack prevention. Welding of a mock up of the irradiated material is necessary to 20

remove the concern for brittle materials. The impact of the conditional acceptance of the Code Case would require an effort to produce an irradiated mockup that is welded under a specified depth of water and testing the welded mockup for crack propagation characteristics. It is estimated that this testing would cost in excess of $4 million. This would include such items as unirradiated prototype weldments, building restraint fixtures, irradiation of samples, actual welding of irradiated weldments, radiological controls, hot cell costs, facility rental, and disposal of irradiated materials.

1.2.4 Code Case N-521, Alternative Rules for Deferral of Inspection of Nozzle-to-Vessel Welds, Inside Radius Sections, and Nozzle-to-Safe End Welds of a Pressurized Water Reactor (PWR) Vessel Code Case N-521 is acceptable subject to the following condition in addition to those conditions specified in the Code Case. When deferring nozzle inspections to the end of the interval, there should be no more than 10 years between inspections, except where the length of a 10 year interval is adjusted in accordance with IWA-2430.

The conditional acceptance would be imposed because of the implication of Footnote 21 of Table IWB-2500 that states, "At least 25% but not more than 50%

(credited) of the nozzles shall be examined by the end of the first inspection interval." With the impacts on schedules, resources, and ALARA from these examinations, it is reasonable to defer the examinations until the end of the interval per Code Case N-521, when all the nozzles can be examined in one inspection. However, if a nozzle is examined during the first period of an interval, using Code Case N-521 would allow examination of that nozzle to be deferred until the end of that interval, allowing approximately 17 years between examinations. It is the conclusion of the staff that nozzles should be inspected at the normal frequency intended by the code, once every 10 years. It is estimated that this conditional acceptance would have minimal impact on industry.

1.2.5 Code Case N-522, Pressure Testing of Containment Penetration Piping Code Case N-522 is acceptable subject to the following condition in addition to those conditions specified in the Code Case. The test should be conducted at the peak calculated containment pressure and the test procedure should permit the detection and location of through-wall leakage in containment isolation valves (CIVs) and pipe segments between the CIVs.

The conditional acceptance would be imposed because of code pressure requirements. Category C-H in Table IWC-2500-1 requires periodic hydrostatic testing be performed on Class 2 piping at least once during every 10-year 21

interval. This provides verification of the leak-tight integrity of the piping system or segments of it. The Appendix J pressure testing provides periodicL verification of the leak-tight integrity of the systems and components that penetrate the primary reactor containment. The Class 2 containment isolation valves (CIVs) and connecting pipe segment must withstand the peak calculated containment internal pressure related to the maximum design containment pressure. The containment penetration piping is classified as Class 2 because of its function as part of the containment pressure boundary, and because containment integrity is the only safety-related function performed by this penetration piping. Therefore, it is logical to test the penetration piping portion of the associated system to the Appendix J criteria. The staff finds that the pressure-retaining integrity of the CIVs and connecting piping may be verified with an Appendix J, Type C, test if conducted at the peak calculated containment pressure. The staff concludes that compliance with Appendix J would provide an acceptable level of quality and safety in lieu of the code-required hydrostatic test of Class 2 piping that penetrates containment where the balance of the piping system is non-code class. The conditional acceptance should have a minimal impact on industry. l 1.3 Need This Revision 12 of Regulatory Guide 1.147 is needed to present the NRC's current position on the ASME Code Cases that have been added, revised, reinstated, reaffirmed, or annulled since Revision 30 of the guide.

1.4 Value/Impact 1.4.1 NRC The guide presents the NRC position on all acceptable and previously acceptable ASME Code Cases. From this document, the NRC reviewing staff can ascertain the NRC position on all Code Cases. Otherwise, the staff would be required to review all applications for use of a Code Case on an individual basis. Using this regulatory guide for review greatly reduces the cost and time to the staff.

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1.4.2 Industry The guide informs the industry of the NRC's position on all acceptable and previously acceptable ASME Code Cases. This document states which Code Cases are acceptable to the NRC and which cases must be accepted on a case-by-case basis. Regulatory Guide 1.147 greatly reduces time and effort for the industry.

1.4.3 Public The public has access to a published document that states the NRC position on all acceptable and previously acceptable ASME Code Cases.

2. STATUTORY CONSIDERATION Authority for the proposed action is derived from the Atomic Energy Act of 1954, as amended, and the Energy Reorganization Act of 1974, as amended and implemented through the Commission's regulations cited in the introduction to the guide.

3.

SUMMARY

AND CONCLUSION The proposed regulatory guide should be issued for public comment.

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