ML052780338

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Proposed Alternative to the American Society of Mechanical Engineers Code,Section XI Requirements for Examination of Dissimilar Metal Piping Welds
ML052780338
Person / Time
Site: Cook  American Electric Power icon.png
Issue date: 09/22/2005
From: Fadel D
Indiana Michigan Power Co
To:
Document Control Desk, Office of Nuclear Reactor Regulation
References
AEP: NRC:5055-11
Download: ML052780338 (30)


Text

z INDIANA Indiana Michigan Power Cook Nuclear Plant MICHIGAN One Cook Place PO ER* Bridgman. Ml 49106 AEP.com A unit of American Electric Power September 22, 2005 AEP:NRC:5055-11 10 CFR 50.55a Docket Nos: 50-315 50-316 U. S. Nuclear Regulatory Commission ATTN: Document Control Desk Mail Stop O-P1-17 Washington, DC 20555-0001 Donald C. Cook Nuclear Plant Units 1 and 2 PROPOSED ALTERNATIVE TO THE AMERICAN SOCIETY OF MECHANICAL ENGINEERS CODE, SECTION XI REQUIREMENTS FOR EXAMINATION OF DISSIMILAR METAL PIPING WELDS Pursuant to 10 CFR 50.55a(a)(3)(i), Indiana Michigan Power Company (I&M), the licensee for Donald C. Cook Nuclear Plant Units 1 and 2, requests Nuclear Regulatory Commission approval of an alternative to the requirements of the American Society of Mechanical Engineers Code (ASME Code),Section XI requirements for examination of dissimilar metal piping butt welds for the third 10-year inservice inspection program interval. to this letter provides a proposed alternative to the qualification requirements of ASME Code,Section XI, Appendix VIII, Supplement 10 for supporting examination of dissimilar metal piping welds. The proposed alternative would allow the use of alternative requirements that have been developed by the industry (to be implemented through the Perfornance Demonstration Initiative program) and which are contained in a proposed revision to Supplement 10. A summary of the proposed revision to Supplement 10 is included as Attachment 2 to this letter.

I&M requests approval of the proposed alternative by January 31, 2006, to support the Unit 2, Cycle 16 refueling outage scheduled to begin in March 2006. This letter contains no new commitments. Should you have any questions, please contact Mr. John A. Zwolinski, Director of Safety Assurance at (269) 466-2428.

Sincerely, Daniel P. Fadel Engineering Vice President RV/rdw

U. S. Nuclear Regulatory Commission AEP:NRC:5055-11 Page 2 Attachments:

1. Proposed Alternative to the Requirements of American Society of Mechanical Engineers Code Section XI.
2. Proposed Revision to American Society of Mechanical Engineers (ASME) Code,Section XI Appendix VIII, Supplement 10 c: R. Aben - Department of Labor and Economic Growth J. L. Caldwell - NRC Region III K. D. Curry - AEP Ft. Wayne, w/o attachments J. T. King - MPSC, wlo attachments MDEQ - WHMDIRPMWS, w/o attachments NRC Resident Inspector D. W. Spaulding - NRC Washington DC

Attachment I to AEP:NRC:5055-11 PROPOSED ALTERNATIVE TO THE REQUIREMENTS OF AMERICAN SOCIETY OF MECHANICAL ENGINEERS CODE SECTION XI 1.0 SYSTEM/COMPONENT (S) FOR W[HICH RELIEF IS REQUESTED Pressure Retaining Piping Welds subject to examination using procedures, personnel, and equipment qualified to American Society of Mechanical Engineers Code (ASME Code)Section XI, Appendix VIII, Supplement 10 criteria. Tables I and 2 respectively, identify the Unit 1 and Unit 2 components included in this request.

2.0 APPLICABLE CODE AND ADDENDA ASME Code,Section XI, Appendix VII, Supplement 10 as required by 10 CFR 50.55a.

3.0 CODE REQUIREMENTS The following paragraphs or statements are from ASME Code,Section XI, Appendix VIII, Supplement 10 and identify the specific requirements that are included in this request for relief.

Item I - Paragraph 1.1(b) states in part - Pipe diameters within a range of 0.9 to 1.5 times a nominal diameter shall be considered equivalent.

Item 2 - Paragraph 1. 1(d) states - All flaws in the specimen set shall be cracks.

Item 3 - Paragraph 1.1(d)(1) states - At least 50 percent (%) of the cracks shall be in austenitic material. At least 50% of the cracks in austenitic material shall be contained wholly in weld or buttering material. At least 10% of the cracks shall be in ferritic material. The remainder of the cracks may be in either austenitic or ferritic material.

Item 4 - Paragraph 1.2(b) states in part - The number of unflawed grading units shall be at least twice the number of flawed grading units.

Item 5 - Paragraph 1.2(c)(1) and 1.3(c) state in part - At least 1/3 of the flaws, rounded to the next higher whole number, shall have depths between 10% and 30% of the nominal pipe wall thickness.

Paragraph 1.4(b) distribution table requires 20% of the flaws to have depths between 10% and 30%.

Item 6 - Paragraph 2.0 first sentence states - The specimen inside surface and identification shall be concealed from the candidate.

Item 7 - Paragraph 2.2(b) states in part - The regions containing a flaw to be sized shall be identified to the candidate.

to AEP:NRC:5055-11 Page 2 Item 8 - Paragraph 2.2(c) states in part - For a separate length sizing test, the regions of each specimen containing a flaw to be sized shall be identified to the candidate.

Item 9 - Paragraph 2.3(a) states - For the depth sizing test, 80% of the flaws shall be sized at a specific location on the surface of the specimen identified to the candidate.

Item 10 - Paragraph 2.3(b) states - For the remaining flaws, the regions of each specimen containing a flaw to be sized shall be identified to the candidate. The candidate shall determine the maximum depth of the flaw in each region.

Item 11 - Table VIII-S2-1 provides the false call criteria when the number of unflawed grading units is at least twice the number of flawed grading units.

4.0 RELIEF REQUESTED Relief is requested to use the following alternative requirements for implementation of the Appendix VIII, Supplement 10 requirements required by 10 CFR 50.55a. They will be implemented through the Performance Demonstration Initiative (PDI) Program.

A copy of the proposed revision to Supplement 10 is attached. It identifies the proposed alternatives and allows them to be viewed in context. It also identifies additional clarifications and enhancements for information. It has been submitted to the ASME Code for consideration and as of September 2002 had been approved by the NDE Subcommittee.

5.0 BASIS FOR RELIEF Item 1 - The proposed alternative to Paragraph 1.1(b) states:

'The specimen set shall include the minimum and maximum pipe diameters and thicknesses for which the examination procedure is applicable. Pipe diameters within 1/2 in. (13 mm) of the nominal diameter shall be considered equivalent. Pipe diameters larger than 24 in. (610 mm) shall be considered to be flat. When a range of thicknesses is to be examined, a thickness tolerance of

+25% is acceptable."

Technical Basis - The change in the minimum pipe diameter tolerance from 0.9 times the diameter to within 1/2 inch of the nominal diameter provides tolerances more in line with industry practice.

Though the alternative is less stringent for small pipe diameters they typically have a thinner wall thickness than larger diameter piping. A thinner wall thickness results in shorter sound path distances that reduce the detrimental effects of the curvature. This change maintains consistency between Supplement 10 and the recent revision to Supplement 2.

to AEP:NRC:5055-11 Page 3 Item 2 - The proposed alternative to Paragraph 1.1(d) states:

"At least 60% of the flaws shall be cracks, the remainder shall be alternative flaws. Specimens with IGSCC shall be used when available. Alternative flaws, shall meet the following requirements:

(1) Alternative flaws, if used, shall provide crack-like reflective characteristics and shall only be used when implantation of cracks would produce spurious reflectors that are uncharacteristic of service-induced flaws.

(2) Alternative flaw mechanisms shall have a tip width no more than 0.002 in. (.05 mm).

Note, to avoid confusion the proposed alternative modifies instances of the term "cracks" or "cracking" to the term "flaws" because of the use of alternative flaw mechanisms."

Technical Basis - As illustrated below, implanting a crack requires excavation of the base material on at least one side of the flaw. While this may be satisfactory for ferritic materials, it does not produce a useable axial flaw in austenitic materials because the sound beam, which normally-passes only through base material, must now travel through weld material on at least one side, producing an unrealistic flaw response. In addition, it is important to preserve the dendritic structure present in field welds that would otherwise be destroyed by the implantation process. To resolve these issues, the proposed alternative allows the use of up to 40% fabricated flaws as an alternative flaw mechanism under controlled conditions. The fabricated flaws are isostatically compressed which produces ultrasonic reflective characteristics similar to tight cracks.

ExcavtionMechanical fatigue crack l C til i n Base inaterial l Item 3 - The proposed alternative to Paragraph 1.1(d)(1) states:

"At least 80% of the flaws shall be contained wholly in weld or buttering material. At least one and no more than 10% of the flaws shall be in ferritic base material. At least one and no more than 10%

of the flaws shall be in austenitic base material."

Technical Basis - Under the current Code, as few as 25% of the flaws are contained in austenitic weld or buttering material. Recent experience has indicated that flaws contained within the weld are the likely scenarios. The metallurgical structure of austenitic weld material is ultrasonically more challenging than either ferritic or austenitic base material. The proposed alternative is therefore more challenging than the current Code.

to AEP:NRC:5055-11 Page 4 Item 4 - The proposed alternative to Paragraph 1.2(b) states:

"Personnel performance demonstration detection test sets shall be selected from Table VIII-S1O-1.

The number of unflawed grading units shall be at least 1-1/2 times the number of flawed grading units."

Technical Basis - Table S10-1 provides a statistically based ratio between the number of unflawed grading units and the number of flawed grading units. The proposed alternative reduces the ratio to 1.5 times to reduce the number of test samples to a more reasonable number from the human factors perspective. However, the statistical basis used for screening personnel and procedures is still maintained at the same level with competent personnel being successful and less skilled personnel being unsuccessful. The acceptance criteria for the statistical basis are in Table VIII-S 10-1.

Item 5 - The proposed alternative to the flaw distribution requirements of Paragraph 1.2(c)(1)

(detection) and 1.3(c) (length) is to use the Paragraph 1.4(b) (depth) distribution table (see below) for all qualifications.

Flaw Depth Minimum

(% Wall Thickness) Number of Flaws 10-30% 20%

31-60% 20%

61-100% 20%

Technical Basis - The proposed alternative uses the depth sizing distribution for both detection and depth sizing because it provides for a better distribution of flaw sizes within the test set. This distribution allows candidates to perform detection, length, and depth sizing demonstrations simultaneously utilizing the same test set. The requirement that at least 75% of the flaws shall be in the range of 10 to 60% of wall thickness provides an overall distribution tolerance yet the distribution uncertainty decreases the possibilities for testmanship that would be inherent to a uniform distribution. It must be noted that it is possible to achieve the same distribution utilizing the present requirements, but it is preferable to make the criteria consistent.

Item 6 - The proposed alternative to Paragraph 2.0 first sentence states:

"For qualifications from the outside surface, the specimen inside surface and identification shall be concealed from the candidate. When qualifications are performed from the inside surface, the flaw location and specimen identification shall be obscured to maintain a "blind test"."

Technical Basis - The current Code requires that the inside surface be concealed from the candidate.

This makes qualifications conducted from the inside of the pipe (e.g., pressurized water reactor nozzle to safe end welds) impractical. The proposed alternative differentiates between inside diameter and outside diameter scanning surfaces, requires that they be conducted separately, and

I to AEP:NRC:5055-11 Page 5 requires that flaws be concealed from the candidate. This is consistent with the recent revision to Supplement 2.

Items 7 and 8 - The proposed alternatives to Paragraph 2.2(b) and 2.2(c) state:

"... containing a flaw to be sized may be identified to the candidate."

Technical Basis - The current Code requires that the regions of each specimen containing a flaw to be length sized shall be identified to the candidate. The candidate shall determine the length of the flaw in each region (Note, that length and depth sizing use the term "regions" while detection uses the term "grading units" - the two terms define different concepts and are not intended to be equal or interchangeable). To ensure security of the samples, the proposed alternative modifies the first "shall" to a "may" to allow the test administrator the option of not identifying specifically where a flaw is located. This is consistent with the recent revision to Supplement 2.

Items 9 and 10 - The proposed alternative to Paragraph 2.3(a) and 2.3(b) state:

"... regions of each specimen containing a flaw to be sized may be identified to the candidate."

Technical Basis - The current Code requires that a large number of flaws be sized at a specific location. The proposed alternative changes the "shall" to a "may" which modifies this from a specific area to a more generalized region to ensure security of samples. This is consistent with the recent revision to Supplement 2. It also incorporates terminology from length sizing for additional clarity.

I to AEP:NRC:5055-11 Page 6 Item 11 - The proposed alternative modifies the acceptance criteria of Table VIII-S2-1 as follows:

~~~~..... II--..

....:A TABLE V1II-PERFORMANCE DEMONSTRATION D E CTION TEST.

ACCEPTANCE .:C~iEI Detection Test False Call Test

~~~~~~~~~~. .. . . ........ ...

j

.. :::cc'E  :'t' ':;E CtEr E Atcepance Criteria EE' nimum Unflae .Flawe ........

. Numr Grading Detction . Gradng of Fale nisCieri Units al 7 . . ....

' '27-:-j 2

1l 0 12.........8 8  ;. io-15(E

. 2. . ... - . . E-;

. '. f 125 1.1 1-2 1 2t2 4- 3,,i

. . . .. .- . . . .~

20 14 4-3208-1,8'l9.l E' 13 3--27E§ .'4E Technical Basis -The proposed alternative is identified as new Table S10-1 above. It was modified to reflect the reduced number of unflawed grading units and allowable false calls. As a part of ongoing Code activities, Pacific Northwest National Laboratories has reviewed the statistical significance of these revisions and offered the revised Table S 10-1.

Attachment I to AEP:NRC:5055-11 Page 7 6.0 ALTERNATIVE EXAMINATION In lieu of the requirements of ASME Code,Section XI, Appendix VIII, Supplement 10 required by 10 CFR 50.55a, the proposed alternative shall be used. The proposed alternative is described in .

7.0 JUSTIFICATION FOR GRANTING RELIEF Pursuant to 10 CFR 50.55a(a)(3)(i), approval is requested to use the proposed alternatives described above in lieu of the ASME Code,Section XI, Appendix VIII, Supplement 10 requirements.

Compliance with the proposed alternatives will provide an adequate level of quality and safety for examination of the affected welds.

8.0 DURATION OF THE RELIEF The relief is requested for the remainder of the third 10-year inservice inspection interval.

9.0 PRECEDENTS Similar requests have been granted for the Virgil C. Summer Nuclear Station, Reference 1, and the Wolf Creek Generation Station, Reference 2.

10.0 REFERENCES

1. Letter from John A. Nakoski, U. S. Nuclear Regulatory Commission (NRC), to Stephen A.

Byrne, Virgil C. Summer Nuclear Station, "Virgil C. Summer Nuclear Station - Second 10-Year Inservice Inspection, Request for Relief RR-II-20, RR-II-20 Addenda, and RR-II-21 (TAC No.

MCO108)," Accession Number ML040340450, dated February 3,2004.

2. Letter from Robert A. Gramm, NRC, to Rick A. Muench, Wolf Creek Nuclear Operating Corporation, "Wolf Creek Generation Station - Relief Requests 12R-29 through 12R-32 Pertaining to Implementation of ASME Code,Section XI Requirements for Examination of Welds (TAC No. MC6478)," Accession Number 051380396, dated May 17, 2005.

to AEP:NRC:5055-11 Page 8 TABLE 1 Unit 1 Components Component Description System Description ASME Item Number Identification 1-RPV-1-01 NOZZLE TO SAFE-END "HOT REACTOR PRESSURE VESSEL AND B5.10 LEG" CLOSURE HEAD SAFE-END TO NOZZLE "COLD REACTOR PRESSURE VESSEL AND B5.10 I-RPV-1-02 LEG" CLOSURE HEAD NOZZLE TO SAFE-END "HOT REACTOR PRESSURE VESSEL AND 15.10 1-RPV-2-01 LEG" CLOSURE HEAD 1-RPV-2-02 SAFE-END TO NOZZLE "COLD REACTOR PRESSURE VESSEL AND B5.10 LEG" CLOSURE HEAD SAFE-END "HOT NOZZLE TO LEG" REACTORCLOSURE PRESSURE VESSEL AND B5.10 1-RPV-3-01 HEAD 1-RPV-3-02 SAFE-END TO NOZZLE "COLD REACTOR PRESSURE VESSEL AND B5.10 1 LEG" CLOSURE HEAD 1-P--1 NOZZLE TO SAFE-END "HOT REACTOR PRESSURE VESSEL ANDB.1 I-P--1LEG" CLOSURE HEAD 51 1-RPV-4-02 SAFE-END TO NOZZLE "COLD REACTOR PRESSURE VESSEL AND B5.10 LEG" CLOSURE HEAD 1-PRZ-20 NOZZLE TO SAFE-END PRESSURIZER B5.40

Attachment I to AEP:NRC:5055-lP Page 9 TABLE 1 Unit 1 Components Component Description System Description ASME Item Number Identification I-PRZ-21 NOZZLE TO SAFE-END PRESSURIZER B5.40 1-PRZ-22 NOZZLE TO SAFE-END PRESSURIZER B5.40 1-PRZ-24 NOZZLE TO SAFE-END PRESSURIZER B5.40 I-PRZ-25 NOZZLE TO SAFE-END PRESSURIZER B5.40 STM-1 1-02R SAFE-END TO INLET NOZZLE STEAM GENERATOR NO. 11 B5.70 STM-11-03R OUTLET NOZZLE TO SAFE-END STEAM GENERATOR NO. 11 B5.70 STM-12-02R SAFE-END TO INLET NOZZLE STEAM GENERATOR NO. 12 B5.70 STM-12-03R OUTLET NOZZLE TO SAFE-END STEAM GENERATOR NO. 12 B5.70 STM-13-02R INLET NOZZLE TO SAFE-END STEAM GENERATOR NO. 13 B5.70 STM-13-03R OUTLET NOZZLE TO SAFE-END STEAM GENERATOR NO. 13 B5.70 to AEP:NRC:5055-11 Page 10 TABLE 1 Unit 1 Components Identimcation Description System Description ASME Item Number STM-14-02R SAFE-END TO INLET NOZZLE STEAM GENERATOR NO. 14 B5.70 STM-14-03R OUTLET NOZZLE TO SAFE-END STEAM GENERATOR NO. 14 B5.70 I-FW-1 1-14F-R SAFE-END TO NOZZLE FEEDWATER SYSTEM C5.51 1-FW-13-14F-R SAFE-END TO NOZZLE FEEDWATER SYSTEM C5.51 FW-16-14F-R SAFE-END TO NOZZLE .- FEEDWATER SYSTEM C..51 1-FW-18-14F-R SAFE-END TO NOZZLE FEEDWATER SYSTEM C5.51 to AEP:NRC:5055-11 Page I 1 TABLE 2 Unit 2 Components Component Description System Description ASME Item Number Identification 2-RPV-1-01 NOZZLE TO SAFE-END "HOT REACTOR PRESSURE VESSEL AND B5.10 LEG" CLOSURE HEAD 2-RPV-1-02 SAFE-END TO NOZZLE "COLD REACTOR PRESSURE VESSEL AND B5.10 LEG" CLOSURE HEAD 2-RPV-2-01 NOZZLE TO SAFE-END "HOT REACTOR PRESSURE VESSEL AND B5.10 LEG" CLOSURE HEAD 2-RPV-2-02 SAFE-END TO NOZZLE "COLD REACTOR PRESSURE VESSEL AND B5.10 LEG" CLOSURE HEAD 2-RPV-3-01 NOZZLE TO SAFE-END "HOT REACTOR PRESSURE VESSEL AND B5.10 LEG" CLOSURE HEAD 2-RPV-3-02 SAFE-END TO NOZZLE "COLD REACTOR PRESSURE VESSEL AND B5.10 LEG" CLOSURE HEAD to AEP:NRC:5055-11 Page 12 TABLE 2 Unit 2 Components Component Description System Description ASME Item Number Identification NOZZLE TO SAFE-END "HOT REACTOR PRESSURE VESSEL AND B5.I1 2-RPV-4-01 LEG" CLOSURE HEAD 2-RPV-4-02 SAFE-END TO NOZZLE "COLD REACTOR PRESSURE VESSEL AND B5.10 7".: I LEG" CLOSURE HEAD

-. _: Is...

W. , . .

2-PRZ-21 NOZZLE TO SAFE-END PRESSURIZER B5.40 2-PRZ-22 NOZZLE TO SAFE-END PRESSURIZER B5.40 2-PRZ-23 NOZZLE TO SAFE-END PRESSURIZER B5.40 2-PRZ-24 NOZZLE TO SAFE-END PRESSURIZER B5.40 2-PRZ-25 NOZZLE TO SAFE-END PRES SURIZER B5.40 2-PRZ-26 SAFE-END TO NOZZLE PRESSURIZER B5.40 STM-21-02 ELBOW TO INLET NOZZLE STEAM GENERATOR NO. 21 B5.70 to AEP:NRC:5055-11 Page 13 TABLE 2 Unit 2 Components Component Description System Description ASME Item Number Identification STM-21-03 OUTLET NOZZLE TO ELBOW STEAM GENERATOR NO. 21 B5.70 STM-22-02 ELBOW TO INLET NOZZLE STEAM GENERATOR NO. 22 B5.70 STM-22-03 OUTLET NOZZLE TO ELBOW STEAM GENERATOR NO. 22 B5.70  %-g 7:

STM-23-02 ELBOW TO INLET NOZZLE STEAM GENERATOR NO. 23 B5.70 STM-23-03 OUTLET NOZZLE TO ELBOW STEAM GENERATOR NO. 23 B5.70 STM-24-02 ELBOW TO INLET NOZZLE STEAM GENERATOR NO. 24 B5.70 STM-24-03 OUTLET NOZZLE TO ELBOW STEAM GENERATOR NO. 24 B5.70

Attachment 2 to AEP:NRC:5055-11 Proposed Revision to American Society of Mechanical Engineers Code (ASME Code)Section XI Appendix VIII, Supplement 10 SUPPLEMENT 10 - QUALIFICATION REQUIREMENTS FOR DISSIMILAR METAL PIPING WELDS Current Requirement Proposed Change Reasoning 1.0 SCOPE Supplement 10 is applicable to dissimilar A scope statement provides added clarity metal piping welds examined from either regarding the applicable range of each the inside or outside surface. individual Supplement. The exclusion of Supplement 10 is not applicable to piping CRC provides consistency between welds containing supplemental corrosion Supplement 10 and the recent revision to resistant clad (CRC) applied to mitigate Supplement 2 (Reference BC 00-755).

Intergranular Stress Corrosion Cracking Note: an additional change identifying CRC (IGSCC). as "in course of preparation" is being

______ processed separately.

1.0 SPECIMEN REQUIREMENTS 2.0 SPECIMEN REQUIREMENTS Renumbered .4 .

Qualification test specimens shall meet the Qualification test specimens shall meet the No Change _I requirements listed herein, unless a set of requirements listed herein, unless a set of specimens is designed to accommodate specimens is designed to accommodate specific limitations stated in the scope of specific limitations stated in the scope of the examination procedure (e.g., pipe size, the examination procedure (e.g., pipe size, weld joint configuration, access weld joint configuration, access limitations). The same specimens may be limitations). The same specimens may be used to demonstrate both detection and used to demonstrate both detection and sizing qualification. sizing qualification.

1.1 General. The specimen set shall 2.1 General. Renumbered conform to the following requirements. The specimen set shall conform to the following requirements.

(a) The minimum number of flaws in a New, changed minimum number of flaws to specimen set shall be ten. 10 so sample set size for detection is

consistent with length and depth sizing.

to AEP:NRC:5055-11 Page 2 SUPPLEMENT 10 - QUALIFICATION REQUIREMENTS FOR DISSIMILAR METAL PIPING WELDS Current Requirement Proposed Change Reasoning (a) Specimens shall have sufficient volume (b) Specimens shall have sufficient volume Renumbered to minimize spurious reflections that may to minimize spurious reflections that may interfere with the interpretation process. interfere with the interpretation process.

(b) The specimen set shall include the (c) The specimen set shall include the Renumbered, metricated, the change in pipe minimum and maximum pipe diameters and minimum and maximum pipe diameters and diameter tolerance provides consistency thicknesses for which the examination thicknesses for which the examination between Supplement 10 and the recent procedure is applicable. Pipe diameters procedure is applicable. Pipe diameters revision to Supplement 2 (Reference within a range of 0.9 to 1.5 times a nominal within 1/2 in. (13 mm) of the nominal BC 00-755) diameter shall be considered equivalent. diameter shall be considered equivalent.

Pipe diameters larger than 24 in. shall be Pipe diameters larger than 24 in. (610 mm) considered to be flat. When a range of shall be considered to be flat. When a range thicknesses is to be examined, a thickness of thicknesses is to be examined, a tolerance of +25% is acceptable. thickness tolerance of +25% is acceptable.

(c) The specimen set shall include examples (d) The specimen set shall include Renumbered, changed "condition" to of the following fabrication condition: examples of the following fabrication "conditions" conditions:

(1) geometric conditions that normally (1) geometric and material conditions that Clarification, some of the items listed relate require discrimination from flaws (e.g., normally require discrimination from flaws to material conditions rather than geometric counterbore or weld root conditions, (e.g., counterbore or weld root conditions, conditions. Weld repair areas were added cladding, weld buttering, remnants of cladding, weld buttering, remnants of as a result of recent field experiences.

previous welds, adjacent welds in close previous welds, adjacent welds in close proximity); proximity, weld repair areas);

(2) typical limited scanning surface (2) typical limited scanning surface Differentiates between inside diameter and conditions (e.g., diametrical shrink, single- conditions shall be included as follows: outside diameter scanning surface side access due to nozzle and safe end (a) for outside surface examination, weld limitations. Requires that ID and OD external tapers). crowns, diametrical shrink, single-side qualifications be conducted independently access due to nozzle and safe end external (Note, new paragraph 2.0 (identical to old tapers paragraph 1.0) provides for alternatives to AEP:NRC:5055-11 Page 3 SUPPLEMENT 10 - QUALIFICATION REQUIREMENTS FOR DISSIMILAR METAL PIPING WELDS Current Requirement Proposed Change Reasoning (b) for inside surface exaniination, when "a set of specimens is designed to internal tapers, exposed weld roots, and accommodate specific limitations stated in cladding conditions for inside surface the scope of the examination procedure.").

examinations).

(e) Qualification requirements shall be satisfied separately for outside surface and inside surface examinations.

(d) All flaws in the specimen set shall be Deleted this requirement, because new cracks. paragraph 2.3 below provides for the use of

_"alternative flaws" in lieu of cracks.

(1) At least 50% of the cracks shall be in 2.2 Flaw Location. Renumbered and re-titled. Flaw location austenitic material. At least 50% of the At least 80% of the flaws shall be percentages redistributed becausqfield cracks in austenitic material shall be contained wholly in weld or buttering experience indicates that flaws contained in ,e C contained wholly in weld or buttering material. At least one and no more than weld or buttering material are probable and material. At least 10% of the cracks shall 10% of the flaws shall be in ferritic base represent the more stringent ultrasonic be in ferritic material. The remainder of the material. At least one and no more than detection scenario.

cracks may be in either austenitic or ferritic 10% of the flaws shall be in austenitic material. base material.

(2) At least 50% of the cracks in austenitic 2.3-Flaw Type. Renumbered and re-titled. Alternative base material shall be either IGSCC or (a) At least 60% of the flaws shall be flaws are required for placing axial flaws in thermal fatigue cracks. At least 50% of the cracks, and the remainder shall be the heat affected zone of the weld and other cracks in ferritic material shall be alternative flaws. Specimens with areas where implantation of a crack mechanically or thermally induced fatigue IGSCC shall be used when available. produces metallurgical conditions that cracks. Alternative flaws shall meet the following result in an unrealistic ultrasonic response.

requirements: This is consistent with the recent revision to (1) Alternative flaws, if used, shall Supplement 2 (Reference BC 00-755).

provide crack-like reflective characteristics and shall only be used The 40% limit on alternative flaws is to AEP:NRC:5055-11 Page 4 SUPPLEMENT 10 - QUALIFICATION REQUIREMENTS FOR DISSIMILAR METAL PIPING WELDS Current Requirement Proposed Change Reasoning when implantation of cracks would needed to support the requirement for up to produce spurious reflectors that are 70% axial flaws. Metricated uncharacteristic of service-induced flaws.

(2) Alternative flaws shall have a tip width no more than 0.002 in. (.05 mm).

(3) At least 50% of the cracks shall be (b) At least 50% of the flaws shall be Renumbered. Due to inclusion of coincident with areas described in (c) coincident with areas described in 2.1(d) "alternative flaws", use of "cracks" is no above. above. longer appropriate.

2.4 Flaw Depth.

All flaw depths shall be greater than 10% of Moved from old paragraph 1.3(c) and 1.4 the nominal pipe wall thickness. Flaw and re-titled. Consistency between depths shall exceed the nominal clad detection and sizing specimen set thickness when placed in cladding. Flaws requirements (e.g., 20% vs. 1/3 flaw depth in the sample set shall be distributed as increments, e.g., original paragraph 1.3(c))

follows:

Flaw Depth Minimum

(% Wall Thickness) Number of Flaws 10-30% 20%

31-60% 20%

61-100% 20%

At least 75% of the flaws shall be in the range of 10 to 60% of wall thickness.

1.2 Detection Specimens. The specimen set Renumbered and re-titled and moved to shall include detection specimens that meet paragraph 3.1(a). No other changes to AEP:NRC:5055-11 Page 5 SUPPLEMENT 10 - OUALIFICATION REQUIREMENTS FOR DISSIMILAR METAL PIPING WELDS CurrentRequirement Proposed Change Reasoning the following requirements.

(a) Specimens shall be divided into grading Renumbered to paragraph 3. l(a)(1). No units. Each grading unit shall include at other changes.

least 3 in. of weld length. If a grading unit is designed to be unflawed, at least 1 in. of unflawed material shall exist on either side of the grading unit. The segment of weld length used in one grading unit shall not be used in another grading unit. Grading units need not be uniformly spaced around the pipe specimen. -

(b) Detection sets shall be selected from Moved to new paragraph 3. 1(a)(2).

  • Table VIII-S2-1. The number of unflawed grading units shall be at least twice the number of flawed grading units.

(c) Flawed grading units shall meet the Flaw depth requirements moved to new following criteria for flaw depth, paragraph 2.4, flaw orientation orientation, and type. requirements moved to new paragraph 2.5, flaw type requirements moved to new paragraph 2.3, "Flaw Type".

(1) All flaw depths shall be greater than Deleted, for consistency in sample sets the 10% of the nominal pipe wall thickness. At depth distribution is the same for detection least 1/3 of the flaws, rounded to the next and sizing.

higher whole number, shall have depths between 10% and 30% of the nominal pipe wall thickness. However, flaw depths shall exceed the nominal clad thickness when placed in cladding. At least 1/3 of the to AEP:NRC:5055-11 Page 6 SUPPLEMENT 10 - QUALIFICATION REQUIREMENTS FOR DISSIMILAR METAL PIPING WELDS Current Requirement Proposed Change Reasoning flaws, rounded to the next whole number, shall have depths greater than 30% of the nominal pipe wall thickness.

(2) At least 30% and no more than 70% of 2.5 Flaw Orientation. Note, this distribution is applicable for the flaws, rounded to the next higher whole (a) For other than sizing specimens at least detection and depth sizing. Paragraph number, shall be oriented axially. The 30% and no more than 70% of the flaws, 2.5(b)(1) requires that all length- sizing remainder of the flaws shall be oriented rounded to the next higher whole number, flaws be oriented circumferentially.

circumferentially. shall be oriented axially. The remainder of the flaws shall be oriented circumferentiall y. .

1.3 Length Sizing Specimens. The Renumbered and re-titled and moved to specimen set shall include length sizing new paragraph 3.2 specimens that meet the following requirements.

(a) All length sizing flaws shall be oriented Moved, included in new paragraph 3.2(a) circumferentially.

(b) The minimum number of flaws shall be Moved, included in new paragraph 2.1 ten. above (c) All flaw depths shall be greater than Moved, included in new paragraph 2.4 10% of the nominal pipe wall thickness. At , above after revision for consistency with least 1/3 of the flaws, rounded to the next detection distribution higher whole number, shall have depths between 10% and 30% of the nominal pipe wall thickness. However, flaw depth shall exceed the nominal clad thickness when placed in cladding. At least 1/3 of the flaws, rounded to the next whole number, shall have depths greater than 30% of the to AEP:NRC:5055-11 Page 7 SUPPLEMENT 10 - QUALIFICATION REQUIREMENTS FOR DISSIMILAR METAL PIPING WELDS Current Requirement Proposed Change Reasoning nominal pipe wall thickness.

1.4 Depth Sizing Specimens. The Moved, included in new paragraphs 2. 1, specimen set shall include depth sizing 2.3, 2.4 specimens that meet the following requirements.

(a) The minimum number of flaws shall be Moved, included in new paragraph 2.1 ten.

(b) Flaws in the sample set shall not be Moved, potential conflict with old wholly contained within cladding and shall paragraph 1.2(c)(1); "However, flaw depths be distributed as follows: shall exceed the nominal clad thickness when placed in cladding." Revised for clarity and included in new paragraph 2.4; to AEP:NRC:5055-11 Page 8 SUPPLEMENT 10 - QUALIFICATION REQUIREMENTS FOR DISSIMILAR METAL PIPING WELDS Current Requirement Proposed Change Reasoning Moved, included in paragraph 2.4 for Flaw Depth Minimum consistent applicability to detection and

(% Wall Thickness) Number of Flaws sizing samples.

10-30% 20%

31-60% 20%

61-100% 20%

The remaining flaws shall be in any of the above categories.

(b) Sizing Specimen sets shall meet the Added for clarity following requirements.

(1) Length-sizing flaws shall be oriented Moved from old paragraph 1.3(a) circumferentially.

(2) Depth sizing flaws shall be oriented as Included for clarity. Previously addressed in 2.5(a). by omission (i.e., length, but not depth had

_ a specific exclusionary statement) 2.0 CONDUCT OF 3.0 PERFORMANCE Renumbered PERFORMANCE DEMONSTRATION DEMONSTRATION The specimen inside surface and Personnel and procedure performance Differentiate between qualifications identification shall be concealed from the demonstration tests shall be conducted conducted from the outside and inside candidate. All examinations shall be according to the following requirements. surface.

completed prior to grading the results and (a) For qualifications from the outside presenting the results to the candidate. surface, the specimen inside surface and Divulgence of particular specimen results or identification shall be concealed from the candidate viewing of unmasked specimens candidate. When qualifications are after the performance demonstration is performed from the inside surface, the prohibited. flaw location and specimen identification shall be obscured to maintain a "blind to AEP:NRC:5055-11 Page 9 SUPPLEMENT 10 - QUALIFICATION REQUIREMENTS FOR DISSIMILAR METAL PIPING WELDS Current Requirement Proposed Change Reasoning test". All examinations shall be completed prior to grading the results and presenting the results to the candidate. Divulgence of particular specimen results or candidate viewing of unmasked specimens after the performance demonstration is prohibited.

2.1 Detection Test. Flawed and unflawed 3.1 Detection Test. Renumbered, moved text to paragraph grading units shall be randomly mixed 3. 1(a)(3)

(a) The specimen set shall include detection Renumbered, moved from old paragraph specimens that meet the following 1.2.

requirements.

(1) Specimens shall be divided into grading Renumbered, moved from old paragraph '.: 41 units. 1.2(a). Metricated. No other changes.

(a) Each grading unit shall include at least 3 in. (76 mm) of weld length.

(b)The end of each flaw shall be separated from an unflawed grading unit by at least 1 in. (25 mm) of unflawed material. A flaw may be less than 3 in. in length.

(c) The segment of weld length used in one grading unit shall not be used in another grading unit.

(d) Grading units need not be uniformly spaced around the pipe specimen.

to AEP:NRC:5055-11 Page 10 SUPPLEMENT 10 - QUALIFICATION REQUIREMENTS FOR DISSIMILAR METAL PIPING WELDS Current Requirement Proposed Change Reasoning (2) Personnel performance demonstration Moved from old paragraph 1.2(b). Table detection test sets shall be selected from revised to reflect a change in the minimum Table VIII-S1O-1. The number of unflawed sample set to 10 and the application of grading units shall be at least 1-1/2 times equivalent statistical false call parameters to the number of flawed grading units. the reduction in unflawed grading units.

Human factors due to large sample size.

(3) Flawed and unflawed grading units shall Moved from old paragraph 2.1 be randomly mixed.

(b) Examination equipment and personnel Moved from old paragraph 3.1. Modified are qualified for detection when personnel to reflect the 100% detection acceptance demonstrations satisfy the acceptance criteria of procedures versus personnel and criteria of Table VIII S10-1 for both equipment contained in new paragraph 4.0 detection and false calls. and the use of 1.5X rather than 2X unflawed grading units contained in new paragraph 3.1(a)(2). Note, the modified table maintains the screening criteria of the:

original Table VHI-S2- 1.

2.2 Length Sizing Test 3.2 Length Sizing Test Renumbered (a) The length sizing test may be conducted (a) Each reported circumferential flaw in Provides consistency between Supplement separately or in conjunction with the the detection test shall be length-sized. 10 and the recent revision to Supplement 2 detection test. (Reference BC 00-755).

to AEP:NRC:5055-11 Page I 1 SUPPLEMENT 10 - QUALIFICATION REQUIREMENTS FOR DISSIMILAR METAL PIPING WELDS Current Requirement Proposed Change Reasoning (b) When the length-sizing test is conducted Change made to ensure security of samples, (b) When the length sizing test is conducted in conjunction with the detection test, and consistent with the recent revision to in conjunction with the detection test, and less than ten circumferential flaws are Supplement 2 (Reference BC 00-755).

less than ten circumferential flaws are detected, additional specimens shall be detected, additional specimens shall be provided to the candidate such that at least Note, length and depth sizing use the term provided to the candidate such that at least ten flaws are sized. The regions containing "regions" while detection uses the term ten flaws are sized. The regions containing a flaw to be sized may be identified to the "grading units". The two terms define a flaw to be sized shall be identified to the candidate. The candidate shall determine different concepts and are not intended to candidate. The candidate shall determine the length of the flaw in each region. be equal or interchangeable.

the length of the flaw in each region.

(c) For a separate length-sizing test, the Change made to ensure security of samples, I '.-

(c) For a separate length sizing test, the regions of each specimen containing a flaw consistent with the recent revision to regions of each specimen containing a flaw to be sized may be identified to the Supplement 2 (Reference BC 00-755). ~

to be sized shall be identified to the candidate. The candidate shall determine candidate. The candidate shall determine the length of the flaw in each region.

the length of the flaw in each region.

(d) Examination procedures, equipment, Moved from old paragraph 3.2(a) includes and personnel are qualified for length-sizing inclusion of "when" as an editorial change.

when the RMS error of the flaw length Metricated.

measurements, as compared to the true flaw lengths, do not exceed 0.75 in. (19 mm).

3.3 Depth Sizing Test Renumbered 2.3 Depth Sizing Test (a) For the depth sizing test, 80% of the (a) The depth-sizing test may be Change made to ensure security of samples, flaws shall be sized at a specific location on conducted separately or in conjunction consistent with the recent revision to the surface of the specimen identified to the with the detection test. For a separate Supplement 2 (Reference BC 00-755).

candidate. depth-sizing test, the regions of each specimen containing a flaw to be sized to AEP:NRC:5055-11 Page 12 SUPPLEMENT 10 - QUALIFICATION REQUIREMENTS FOR DISSIMILAR METAL PIPING WELDS Current Requirement Proposed Change Reasoning may be identified to the candidate. The candidate shall determine the maximum depth of the flaw in each region.

(b) For the remaining flaws, the regions of (b) When the depth-sizing test is Change made to be consistent with the each specimen containing a flaw to be sized conducted in conjunction with the recent revision to Supplement 2 (Reference shall be identified to the candidate. The detection test, and less than ten flaws are BC 00-755).

candidate shall determine the maximum detected, additional specimens shall be depth of the flaw in each region. provided to the candidate such that at Changes made to ensure security of least ten flaws are sized. The regions of samples, consistent with the recent revision each specimen containing a flaw to be sized to Supplement 2 (Reference BC 00-755).

may be identified to the candidate. The candidate shall determine the maximum depth of the flaw in each region. . .

I ^ .

(c) Examination procedures, equipment, Moved from old paragraph 3.2(b).

and personnel are qualified for depth sizing Metricated.

when the RMS error of the flaw depth measurements, as compared to the true flaw depths, do not exceed 0.125 in. (3 mm).

3.0 ACCEPTANCE CRITERIA Delete as a separate category. Moved to new paragraph detection (3.1) and sizing 3.2 and 3.3 3.1 Detection Acceptance Criteria. Moved to new paragraph 3. 1(b), reference Examination procedures, equipment, and changed to Table S 10 from S2 because of personnel are qualified for detection when the change in the minimum number of flaws the results of the performance and the reduction in unflawed grading units demonstration satisfy the acceptance from2X to 1.5X.

criteria of Table VIII-S2-1 for both detection and false calls.

to AEP:NRC:5055-11 Page 13 SUPPLEMENT 10 - QUALIFICATION REQUIREMENTS FOR DISSIMILAR METAL PIPING WELDS Current Requiremenit Proposed Change Reasoning 3.2 Sizing Acceptance Criteria Deleted as a separate category. Moved to new paragraph on length 3.2 and depth 3.3 (a) Examination procedures, equipment, Moved to new paragraph 3.2(d), included and personnel are qualified for length sizing word "when" as an editorial change.

the RMS error of the flaw length measurements, as compared to the true flaw lengths, is less than or equal to 0.75 inch.

(b) Examination procedures, equipment, Moved to new paragraph 3.3(c) and personnel are qualified for depth sizing when the RMS error of the flaw depth .1 -

measurements, as compared to the true flaw il.-I-1`7t depths, is less than or equal to 0.125 in. 1. 11.

, N 4.0 PROCEDURE QUALIFICATION New - I - .--

Procedure qualifications shall include the New. Based on experience gained in following additional requirements. conducting qualifications, the equivalent of (a) The specimen set shall include the 3 personnel sets (i.e., a minimum of 30 equivalent of at least three personnel flaws) is required to provide enough flaws performance demonstration test sets. to adequately test the capabilities of the Successful personnel performance procedure. Combining successful" demonstrations may be combined to demonstrations allows a variety of satisfy these requirements. examiners to be used to qualify the (b) Detectability of all flaws in the procedure. Detectability of each flaw procedure qualification test set that are within the scope of the procedure is within the scope of the procedure shall be required to ensure an acceptable personnel demonstrated. Length and depth sizing pass rate. The last sentence is equivalent to shall meet the requirements of paragraph the previous requirements and is 3.1, 3.2, and 3.3. satisfactory for expanding the essential (c) At least one successful personnel variables of a previously qualified to AEP:NRC:5055-11 Page 14 SUPPLEMENT 10 - QUALIFICATION REQUIREMENTS FOR DISSIMILAR METAL PIPING WELDS Current Requirement Proposed Change Reasoning demonstration shall be performed. procedure (d) To qualify new values of essential variables, at least one personnel qualification set is required. The acceptance criteria of 4.0(b) shall be met.

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