L-03-124, Qualification Requirements for Dissimilar Metal Piping Welds

Qualification Requirements for Dissimilar Metal Piping Welds

ML032380038
Person / Time
Site:	Beaver Valley
Issue date:	08/22/2003
From:	Pearce L FirstEnergy Nuclear Operating Co
To:	Document Control Desk, Office of Nuclear Reactor Regulation
References
BV3-BF-01, L-03-124
Download: ML032380038 (24)

Text

Beaver Valley Power Station o fNOC Route 168

__11% ~~~~~~~~~~~~~

Box 4 FirstEnergy Nclear Operating Company Shippingport, PA 15077-0004 L William Pearce 724-682-5234 Site Vice President Fax: 724-643-8069 August 22, 2003 L-03-124 U. S. Nuclear Regulatory Commission Attention: Document Control Desk Washington, DC 20555-0001

Subject:

Beaver Valley Power Station, Unit No. 1 and No. 2 BV-1 Docket No. 50-334, License No. DPR-66 BV-2 Docket No. 50-412, License No. NPF-73 Qualification Requirements for Dissimilar Metal Piping Welds (Relief Request No. BV3-BF-01)

This letter submits proposed alternatives to the requirements of Title 10 of the Code of Federal Regulations (10 CFR), Section 50.55a, concerning the Inservice Inspection (ISI)

Programs for FirstEnergy Nuclear Operating Company (FENOC) Beaver Valley Power Station (BVPS) Units 1 and 2.

Supplement 10 to Appendix VIII, "Performance Demonstration for Ultrasonic Examination Systems" of Section XI of the American Society of Mechanical Engineers Boiler and Pressure Vessel Code (ASME Code) contains the qualification requirements for procedures, equipment, and personnel involved with examining dissimilar metal welds using ultrasonic techniques. In lieu of these ASME Code requirements, this submittal is requesting to use the dissimilar metal weld criteria of the Electric Power Research Institute (EPRI) Performance Demonstration Initiative (PDI) Program.

BVPS Unit 1 is currently in its Third 10-year ISI Interval. BVPS Unit 2 is currently in its Second 10-year ISI Interval. The ASME Code Year of record for the current Interval at both Units is the 1989 Edition, no addenda.

Pursuant to 10 CFR 50.55a(a)(3)(i), FENOC is submitting Relief Request BV3-BF-0l (Enclosure 1) to use the EPRI PDI dissimilar metal weld criteria in lieu of the requirements of ASME Section XI, Appendix VIII, Supplement 10. Enclosure 2 contains a copy of the proposed revisions to Supplement 10 as provided by the PDI.

Beaver Valley Power Station, Unit No. 1 and No. 2 t , A. .. .

Qualification Requirements for Dissimilar Metal Piping Welds (Relief Request No. BV3-BF-O1)

L-03-124 Page 2 No new commitments are contained in this submittal. If there are any questions regarding this matter, please contact Mr. Larry R. Freeland, Manager, Regulatory Affairs/Performance Improvement at 724-682-5284.

Sincerely, WA LC-

)f0 L. William Pearce Enclosures c: Mr. T. G. Colburn, NRR Senior Project Manager Mr. D. M. Kern, NRC Sr. Resident Inspector Mr. H. J. Miller, NRC Region I Administrator

ENCLOSURE 1 Relief for Qualification Requirements for Dissimilar Metal Piping Welds Relief Request No. BV3-BF-01

Relief for Qualification Requirements for Dissimilar Metal Piping Welds Relief Request No. BV3-BF-01 Code Class: Class 1 Code

References:

1989 Edition, No Addenda of the American Society of Mechanical Engineers (ASME) Code, Section Xl Examination Category: B-F Inspection Intervals: Third 10-Year ISI Interval (BV1)

Second 10-Year ISI Interval (BV2)

COMPONENTS FOR WHICH RELIEF IS REQUESTED Dissimilar metal piping welds subject to ultrasonic examination using procedures, personnel, and equipment qualified to 1995 Edition, 1996 Addenda, of the ASME Code, Section Xl, Appendix VIII, Supplement 10, "Qualification Requirements for Dissimilar Metal piping Welds."

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

Item 1 - 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% 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.

Relief for Qualification Requirements for Dissimilar Metal Piping Welds 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.

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

PROPOSED ALTERNATIVES AND BASIS FOR LICENSING ACTION REQUEST In lieu of the ASME Code requirements listed above, this submittal is requesting to use the dissimilar metal weld criteria of the Electric Power Research Institute (EPRI)

Performance Demonstration Initiative (PDI) Program. The following PDI alternatives to the ASME Code, Section Xl Appendix VilI, Supplement 10 requirements are proposed for use during the remainder of the current 10-year ISI intervals for both Beaver Valley Power Station Units 1 and 2. The proposed alternatives will be implemented through the PDI Program.

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 a range of 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."

Page 2 of 7 Relief Request BV3-BF-01

Relief for Qualification Requirements for Dissimliar.Metal Piping Welds Technical Basis - The change in the minimum pipe diameter tolerance from 0.9 times the diameter to the nominal diameter minus 0.5 inch 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.

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, if used, shall provide crack-like reflective characteristics and shall be limited to the case where implantation of cracks produces spurious reflectors that are uncharacteristic of actual flaws. Alternative flaw mechanisms shall have a tip width of less than or equal to 0.002 in. (.05 mm)."

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.

Mechanical fatigue crack

/Ce'ea 1~161- in Base mnaterial 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 a maximum of 10% of the flaws shall be in ferritic base material. At least one and a maximum of 10% of the flaws shall be in austenitic base material."

Page 3 of 7 Relief Request BV3-BF-01

Relief for Qualification Requirements for

Js- Dissimilar Metal Piping Welds Technical Basis - Under the current ASME Code requirement, 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 ASME Code.

Item 4 - The proposed alternative to Paragraph 1.2(b) states:

"Detection sets shall be selected from Table VIII-S 10-1. The number of unflawed grading units shall be at least one and a half times the number of flawed grading units."

Technical Basis - Table S1 0-1 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-S10-1.

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.

Page 4 of 7 Relief Request BV3-BF-01

Relief for Qualification Requirements for Dissimilar Metal Piping Welds Item 6 - The proposed alternative to Paragraph 2.0 first sentence states:

"Forqualifications 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 ASME Code requires that the inside surface be concealed from the candidate. This makes qualifications conducted from the inside of the pipe (e.g., PWR nozzle to safe end welds) impractical. The proposed alternative differentiates between ID and OD scanning surfaces, requires that they be conducted separately, and requires that flaws be concealed from the candidate.

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 ASME 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:

A.. 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.

Page 5 of 7 Relief Request BV3-BF-01

Relief for Qualification Requirements for Dissimilar Metal Piping Welds Item 11 - The proposed alternative modifies the acceptance criteria of Table VIII-S2-1 as follows:

TABLE VIII-Sl PERFORMANCE DEMONSTRATION DETECTION TEST ACCEPTANCE CRITERIA Detection Test False Call Test Acceptance Critera Acceptance Criteria No. of No. of Maximum Flawed Minimum Unflawed Number Grading Detection Grading of False Units Criteria Units Calls

_ 5 10 0 6 6 14 1 9 7 10 2 10 8 20- 15 3- 2 11 9 22 17 3-3 12 9 2+-18 3 3 13 10 26 20 4 3 14 10 26 1 5 3 15 1l 23 5 3 16 12 3-. 24 6 4 17 12 34 24 18 13 a6 26 4 19 13 3e 27 4 20 14 40-29 e-- 4 Technical Basis - The proposed alternative adds new Table Vill-S1O-1 above. It is a modified version of Table Vil-S2-1 to reflect the reduced number of unflawed grading units and allowable false calls. As provided by the PDI as a part of ongoing Code activities, Pacific Northwest National Laboratories has reviewed the statistical significance of these revisions and offered the revised Table Vill-S1O-1.

ALTERNATIVE EXAMINATION In lieu of the requirements of ASME Section Xl, 1995 Edition, 1996 Addenda, Appendix Vil, Supplement 10, the proposed alternative shall be used.

Relief Request BV3-BF-01 of 77 Page 66 of Relief Request BV3-BF-01

Relief for Qualification Requirements for Dissimilar Metal Piping Welds 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 Section Xl, Appendix VilI, Supplement 10 requirements. Compliance with the proposed alternatives will provide an acceptable level of quality and safety for ultrasonic examination of the affected welds.

IMPLEMENTATION SCHEDULE The next scheduled ultrasonic examinations of welds configurations governed by ASME Section Xl, Appendix VIII, Supplement 10 at Beaver Valley Power Station are:

Beaver Valley Power Station Unit 1 - 1Ri 6 (Fall 2004)

Beaver Valley Power Station Unit 2 - 2R1 1 (Spring 2005)

However, the potential to perform ultrasonic examinations of dissimilar metal welds exists now. Approval of the submitted alternatives to Supplement 10 examination requirements will allow implementation of the alternatives and expedite full licensee compliance with respect to 10 CFR 50.55a(g)(6)(ii)(C)(2), as stated within RIS 2003-01.

PRECEDENTS A similar request was approved by the NRC on July 16, 2003 [ADAMS Accession Number ML031970111] based on the March 26, 2003 submittal for the following plants:

Braidwood Station, Units 1 and 2 Byron Station, Units 1 and 2 Clinton Power Station Dresden Nuclear Power Station, Units 2 and 3 LaSalle County Station, Units 1 and 2 Oyster Creek Generating Station Peach Bottom Atomic Power Station, Units 2 and 3 Quad Cities Nuclear Power Station, Units 1 and 2 Three Mile Island, Unit 1 Page 7 of 7 Relief Request BV3-BF-01

ENCLOSURE 2 Supplemental Information Provided by the EPRI Performance Demonstration Initiative (PDI)

SUPPLEMENT 10 - QUALIFICATION REQUIREMENTS FOR DISSIMILAR METAL PIPING WELDS Current Requirement Proposed Change Reasoning 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 Qualification test specimens shall meet the Qualification test specimens shall meet the No Change 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. The specimen set shall Renumbered conform to the following requirements. conform to the following requirements.

(a) The minimum number of flaws In a New, changed minimum number of flaws to test set shall be ten. 10 so sample set size for detection is consistent with length and depth sizing.

(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 Page I of 13 Enclosure 2

SUPPLEMENT 10- QUALIFICATION REQUIREMENTS FOR DISSIMILAR METAL PIPING WELDS Current Requirement lProped Change Reasoning procedure is applicable. Pipe diameters procedure is applicable. Pipe diameters revision to Supplement 2 (Reference BC within a range of 0.9 to 1.5 times a nominal within a range of 1/2 in. (13 mm) of the 00-755) diameter shall be considered equivalent. nominal diameter shall be considered Pipe diameters larger than 24 in. shall be equivalent. Pipe diameters larger than 24 in.

considered to be flat. When a range of (610 mm) shall be considered to be flat.

thicknesses is to be examined, a thickness When a range of thicknesses is to be tolerance of +25% is acceptable. examined, a 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, and weld repair areas);

(2) typical limited scanning surface (2) typical limited scanning surface Differentiates between ID and OD scanning conditions (e.g., diametrical shrink, single- conditions (e.g., weld crowns, diametrical surface limitations. Requires that ID and side access due to nozzle and safe end shrink, single-side access due to nozzle and OD qualifications be conducted external tapers). safe end external tapers for outside surface independently (Note, new paragraph 2.0 examinations; and internal tapers, (identical to old paragraph 1.0) provides for,+

exposed weld roots, and cladding alternatives when "a set of specimens is conditions for inside surface designed to accommodate specific examinations). Qualification limitations stated in the scope of the requirements shall be satisfied separately examination procedure.").

for outside surface and Inside surface examinations.

(d) All flaws in the specimen set shall be Deleted this requirement, because new cracks. Iparagraph 2.3 below provides for the use of Page 2 of 13 Enclosure 2

"alternative flaws" in lieu of cracks.

(1) At least 50% of the cracks shall be in 2.2 Flaw Location. At least 80% of the Renumbered and re-titled. Flaw location austenitic material. At least 50% of the flaws shall be contained wholly in weld or percentages redistributed because field cracks in austenitic material shall be buttering material. At least one and a experience indicates that flaws contained in contained wholly in weld or buttering maximum of 10% of the flaws shall be in weld or buttering material are probable and material. At least 10% of the cracks shall be ferritic base material. At least one and a represent the more stringent ultrasonic in ferritic material. The remainder of the maximum of 10% of the flaws shall be in detection scenario.

cracks may be in either austenitic or ferritic austenitic base material.

material.

(2) At least 50% of the cracks in austenitic 23 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, the remainder shall be alternative the HAZ of the weld and other areas where cracks in ferritic material shall be flaws. Specimens with IGSCC shall be implantation of a crack produces mechanically or thermally induced fatigue used when available. Alternative flaws, If metallurgical conditions that result in an cracks. used, shall provide crack-like reflective unrealistic ultrasonic response. This is characteristics and shall be limited to the consistent with the recent revision to case where Implantation of cracks Supplement 2 (Reference BC 00-755).

produces spurious reflectors that are uncharacteristic of actual flaws. The 40% limit on alternative flaws is Alternative flaw mechanisms shall have a needed to support the requirement for up to tip width of less than or equal to 0.002 in. 70% axial flaws. Metricated

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

Page 3 of 13 Enclosure 2

SUPPLEMENT 10- QUALIFICATION REQUIREMENTS FOR DISSIMILAR METAL PIPING WELDS r Current Requirement Proposed Change Reasoning distributed as 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 the following requirements. _

(a) Specimens shall be divided into grading Renumbered to paragraph 3.1(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 Page 4 of 13 Enclosure 2

SUPPLEMENT 10 - QUALIFICATION REQUIREMENTS FOR DISSIMILAR METAL PIPING WELDS Current Requirement Proposed Change Reasoning orientation, and type. requirements moved to new paragraph 2.5, flaw type requirements moved to new paragrah 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 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) At least 30% and no more than 70% of detection and depth sizing. Paragraph number, shall be oriented axially. The the flaws, rounded to the next higher whole 2.5(b)(1) requires that all length- sizing remainder of the flaws shall be oriented number, shall be oriented axially. The flaws be oriented circumferentially.

circumferentially. remainder of the flaws shall be oriented circumferentially.

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 Page 5 of 13 Enclosure 2

SUPPLEMENT 10 - QUALIFICATION REQUIREMENTS FOR DISSIMILAR METAL PIPING WELDS 0, Current Requirement Proposed Change Reasonin 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 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 I clarity and included in new paragraph 2.4 Page 6 of 13 Enclosure 2

SUPPLEMENT 10 - QUALIFICATION REQUIREMENTS FOR DISSIMILAR METAL PIPING WELDS e.,

Current Requirement Proposed Change Reasoning Flaw Depth Minimum Moved, included in paragraph 2.4 for

(% Wall Thickness) Number of Flaws consistent applicability to detection and 10-30% 20% sizing samples.

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) All 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 CONDUCT OF Renumbered PERFORMANCE DEMONSTRATION PERFORMANCE DEMONSTRATION The specimen inside surface and For qualifications from the outside Differentiate between qualifications identification shall be concealed from the surface, the specimen inside surface and conducted from the outside and inside candidate. All examinations shall be Identification shall be concealed from the surface.

completed prior to grading the results and candidate. When qualifications are presenting the results to the candidate. performed from the inside surface, the Divulgence of particular specimen results or flaw location and specimen Identification candidate viewing of unmasked specimens shall be obscured to maintain a "blind after the performance demonstration is test". All examinations shall be completed prohibited. 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. I Page 7 of 13 Enclosure 2

• 1 2.1 Detection Test. Flawed and unflawed 3.1 Detection Qualification. 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 units. Each grading unit shall include at 1.2(a). Metricated. No other changes.

least 3 in. (76 mm) of weld length. If a grading unit is designed to be unflawed, at least 1 in. (25 mm) 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.

(2) Detection sets shall be selected from Moved from old paragraph 1.2(b). Table Table VIII-S1O-1. The number of unflawed revised to reflect a change in the minimum grading units shall be at least one and a sample set to 10 and the application of half times the number of flawed grading equivalent statistical false call parameters to 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.

Page 8 of 13 Enclosure 2

SUPPLEMENT 10- QUALIFICATION REQUIREMENTS FOR DISSIMILAR METAL PIPING WELDS Current Requirement lProosed Change Reasoning (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 VIII-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).

Page 9 of 13 Enclosure 2

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

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

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

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, is less than or equal to 0.75 in. (19 mm).

2.3 Depth Sizing Test 3.3 Depth Sizing Test Renumbered (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 may be identified to the candidate. The candidate shall determine the maximum I__

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 Page 10 of 13 Enclosure 2

a-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.

(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, is less than or equal to 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 S10 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 from 2X to 1.5X.

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

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 Page 11 of 13 Enclosure 2

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 measurements, as compared to the true flaw depths, is less than or equal to 0.125 in.

4.0 PROCEDURE QUALIFICATION New 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 sets. flaws) is required to provide enough flaws Successful personnel demonstrations may to adequately test the capabilities of the be combined to satisfy these procedure. Combining successful requirements. demonstrations allows a variety of (b) Detectabliity of all flaws within the examiners to be used to qualify the scope of the procedure shall be procedure. Detectability of each flaw demonstrated. Length and depth sizing within the scope of the procedure is shall meet the requirements of paragraph required to ensure an acceptable personnel 3.2 and 3.3. pass rate. The last sentence is equivalent to (c) At least one successful personnel the previous requirements and is demonstration has been performed. satisfactory for expanding the essential (d) To qualify new values of essential variables of a previously qualified variables, at least one personnel procedure qualification set Is required.

Page 12 of 13 Enclosure 2

SUPPLEMENT 10 - QUALIFICATION REQUIREMENTS FOR DISSIMILAR METAL PIPING WELDS _ _

Current Requirement i Pioposed Change Reasoning 6 10 TABLE VIII-PERFORMANCE DEMONSTRAT ON DETECTION TEST ACCEPTANCE CRITERIA Detection Test False Call Test Acceptance Critera Acceptance Criteria No. of No. of Maximum Flawed Minimum Unflawed Number Grading Detection Grading of False Units Criteria Units Calls 6 6 14 1 7 16 2 9 1i27 10 8 2o-15 3-2 11 9 22-17 3 12 9 24- 18 3 3 13 10 26 20 . 3 14 10 2-2 5-15 11 3e_ 21 5 3 16 12 Z3- 6 17 12 34 24 j- 4 18 13 36- 26 4 19 13 3e- 27 7-4 20 14 4- 29 8-- 4 Page 13 of 13 Enclosure 2