ML023600380

Implementation of the Performance Demonstration Methods Supplement Ten (10) - Qualification Requirements for Dissimilar Metal Piping Welds

ML023600380
Person / Time
Site:	Limerick
Issue date:	12/13/2002
From:	Gallagher M Exelon Nuclear
To:	Document Control Desk, Office of Nuclear Reactor Regulation
References
Download: ML023600380 (22)

Text

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Exelon Nuclear wwwexelonorpcorn Nuclear 2oo Exelon Way Kennett Square, PA 19348 10 CFR 50.55a December 13, 2002 U. S. Nuclear Regulatory Commission Attn: Document Control Desk Washington, DC 20555 Limerick Generating Station, Units 1 and 2 Facility Operating License Nos. NPF-39 and NPF-85 NRC Docket Nos. 50-352 and 50-353

Subject:

Implementation of the Performance Demonstration Methods Supplement Ten (10) - "Qualification Requirements for Dissimilar Metal Piping Welds"

Dear Sir/Madam:

Pursuant to 10 CFR 50.55a(a)(3)(i), Exelon Generation Company (Exelon), LLC requests approval of a proposed alternative concerning performance demonstration methods for ultrasonic examination systems for Limerick Generating Station (LGS), Units 1 and 2.

Specifically, this proposed alternative concerns dissimilar metal piping welds as implemented by Supplement 10. The proposed alternative is described in Attachment 1. Attachment 2 contains a copy of the proposed revisions to Supplement 10 as provided by the Performance Demonstration Initiative (PDI). These proposed revisions provided by the PDI identify additional clarifications and enhancements.

We request your review and approval by February 14, 2003 in order to support the examination of dissimilar metal welds during the upcoming outage at LGS, Units 1 and 2.

If you have any questions, please contact us.

Very truly yours, Michael P. Gallagher Director, Licensing and Regulatory Affairs Mid-Atlantic Regional Operating Group Enclosures cc:

H. J. Miller, Administrator, Region I, USNRC A. L. Burritt, USNRC Senior Resident Inspector, LGS S. Wall, Project Manager, USNRC

ATTACHMENT 1 ALTERNATIVE NUMBER VIII-4 DISSIMILAR METAL PIPING WELDS

T ALTERNATIVE NUMBER VIII-4 DISSIMILAR METAL PIPING WELDS Limerick Generating Station, Units 1 and 2 ASME Code Components Affected Dissimilar metal piping welds subject to examination using procedures, personnel, and equipment qualified to ASME Section XI, Appendix VIII, Supplement 10 criteria.

Applicable Code Edition and Addenda

Limerick Generating Station (LGS), Units 1 and 2 are committed to the 1989 Edition, no Addenda, of the ASME Code.

Applicable Code Requirement

The following paragraphs or statements are from ASME Section XI, Appendix VIII, 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 1.11(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.

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.

Alternative Number VIll-4, Dissimilar Metal Piping Welds Page 2 of 7 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.

Reason for Request

Relief is requested to use the following alternative requirements for implementation of Appendix VIII, Supplement 10 requirements.

They will be implemented through the PDI Program.

As provided by the Performance Demonstration Initiative (PDI) in Attachment 2, 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.

Proposed Alternative and Basis for Use Pursuant to 10 CFR 50.55a(a)(3)(i), in lieu of the requirements of ASME Section XI, 1995 Edition, 1996 Addenda, Appendix VIII, Supplement 10, the proposed alternative discussed below shall be used. Compliance with the proposed alternatives will provide an adequate level of quality and safety for examination of the affected welds.

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."

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.

Alternative Number VIII-4, Dissimilar Metal Piping Welds Page 3 of 7 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.

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."

a.

Mechanical fatigue crack in Base material 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."

Technical Basis - Under the current Code, as few as 25% of the flaws are contained in austenitic weld or buttering material.

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.

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

"Detection sets shall be selected from Table VIII-S10-1. The number of unflawed grading units shall be at least one and a half times the number of flawed grading units."

Technical Basis - New Table VIII-S10-1 provides a statistically based ratio between the number of unflawed grading units and the number of flawed grading units. Based on

Alternative Number VIII-4, Dissimilar Metal Piping Welds Page 4 of 7 information provided by the PDI, the proposed alternative reduces the ratio to 1.5 times to reduce the number of test samples to a more reasonable number. 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 0-1.

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.,

PWR nozzle to safe end welds) impractical.

The proposed altemative 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 Code requires that the regions of each specimen containing a flaw to be length sized shall be identified to the candidate. The candidate

Alternative Number VIII-4, Dissimilar Metal Piping Welds Page 5 of 7 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").

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.

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

"... 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.

Item 11 - The proposed alternative modifies the acceptance criteria of Table VIII-S2-1 as follows:

Alternative Number VIII-4, Dissimilar Metal Piping Welds Page 6 of 7 TABLE VIII-S -1 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

5 100 7

6 14 1

8 7

16 2

9 7

18 2

10 8

2o-15 3-2 11 9

2-2-17 3-3 12 9

24-18 3--3 13 10 2fT-20 4-3 14 10 28-21 5-3 15 11 3&-- 23 5--

3 16 12 3-2---24 6-- 4 17 12 34-26 6-4 18 13 36-27 7--- 4 19 13 38-29 7-4 20 14 408-3--

5 Technical Basis - The proposed alternative adds new Table VIII-S10-1 above. It is a modified version of Table VIII-S2-1 to reflect the reduced number of unflawed grading units and allowable false calls.

As provided by the PDI, as part of ongoing Code activities, Pacific Northwest National Laboratories has reviewed the statistical significance to this new Table VIII-S10-1.

Alternative Number VIII-4, Dissimilar Metal Piping Welds Page 7 of 7 Duration of Proposed Alternative The proposed alternative is for the use of the remainder of the second ten (10) year interval.

Precedents None References None

ATTACHMENT 2 SUPPLEMENTAL INFORMATION PROVIDED BY THE PERFORMANCE DEMONSTRATION INITIATIVE (PDI)

Supplemental Information Provided by the Performance Demonstration Initiative (PDI)

Page 1 of 12 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. Supplement individual Supplement. The exclusion of 10 is not applicable to piping welds CRC provides consistency between containing supplemental corrosion Supplement 10 and the recent revision to resistant clad (CRC) applied to mitigate Supplement 2 (Reference BC 00-755). Note, Intergranular Stress Corrosion Cracking an additional change identifying CRC as "in (IGSCC).

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 the specific limitations stated in the scope of the examination procedure (e.g., pipe size, weld examination procedure (e.g., pipe size, weld joint configuration, access limitations). The joint configuration, access limitations). The same specimens may be used to same specimens may be used to demonstrate both detection and sizing demonstrate both detection and sizing qualification, qualification.

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

to the following requirements.

(a) The minimum number of flaws in a test New, changed minimum number of flaws to set shall be ten.

10 so sample set size for detection is consistent with length and depth sizing.

(a) Specimens shall have sufficient volume to (b) Specimens shall have sufficient volume to Renumbered minimize spurious reflections that may minimize spurious reflections that may interfere with the interpretation process.

interfere with the interpretation process.

Supplemental Information Provided by the Performance Demonstration Initiative (PDI)

Page 2 of 12 SUPPLEMENT 10 - QUALIFICATION REQUIREMENTS FOR DISSIMILAR METAL PIPING WELDS Current Requirement Proposed Change Reasoning (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 BC 00 within a range of 0.9 to 1.5 times a nominal within a range of 1/2 in. (13 mm) of the 755).

diameter shall be considered equivalent. Pipe nominal diameter shall be considered 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 examples Renumbered, changed "condition" to of the following fabrication condition:

of the following fabrication conditions:

"conditions".

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

adjacent welds in close proximity);

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

(2) typical limited scanning surface conditions (2) typical limited scanning surface conditions Differentiates between ID and OD scanning (e.g., diametrical shrink, single-side access (e.g., weld crowns, diametrical shrink, surface limitations. Requires that ID and OD due to nozzle and safe end external tapers).

single-side access due to nozzle and safe qualifications be conducted independently end external tapers for outside surface (Note, new paragraph 2.0 (identical to old examinations; and internal tapers, paragraph 1.0) provides for alternatives when exposed weld roots, and cladding "a set of specimens is designed to conditions for inside surface accommodate specific limitations stated in examinations). Qualification requirements the scope of the examination procedure").

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.

Supplemental Information Provided by the Performance Demonstration Initiative (PDI)

Page 3 of 12 SUPPLEMENT 10 - QUALIFICATION REQUIREMENTS FOR DISSIMILAR METAL PIPING WELDS Current Requirement Proposed Change Reasoning (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 cracks flaws shall be contained wholly in weld or percentages redistributed because field in austenitic material shall be contained buttering material. At least one and a experience indicates that flaws contained in wholly in weld or buttering material. At least maximum of 10% of the flaws shall be in weld or buttering material are probable and 10% of the cracks shall be in ferritic material.

ferritic base material. At least one and a represent the more stringent ultrasonic The remainder of the cracks may be in either maximum of 10% of the flaws shall be in detection scenario.

austenitic or ferritic material.

austenitic base material.

(2) At least 50% of the cracks in austenitic 2.3 Flaw Type.

Renumbered and re-titled. Alternative flaws base material shall be either IGSCC or (a) At least 60% of the flaws shall be are required for placing axial flaws in the HAZ thermal fatigue cracks. At least 50% of the cracks, the remainder shall be alternative 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 needed Alternative flaw mechanisms shall have a to support the requirement for up to 70%

tip width of less than or equal to 0.002 in.

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 "alternative coincident with areas described in (c) above, coincident with areas described in 2.1 (d) flaws", use of "cracks" is no longer above.

appropriate.

Supplemental Information Provided by the Performance Demonstration Initiative (PDI)

Page 4 of 12 SUPPLEMENT 10- QUALIFICATION REQUIREMENTS FOR DISSIMILAR METAL PIPING WELDS Current Requirement Proposed Change Reasoning 2.4 Flaw Depth. All flaw depths shall be Moved from old paragraph 1.3(c) and 1.4 and greater than 10% of the nominal pipe wall re-titled. Consistency between detection and thickness. Flaw depths shall exceed the sizing specimen set requirements (e.g., 20%

nominal clad thickness when placed in vs. 1/3 flaw depth increments, e.g., original cladding. Flaws in the sample set shall be paragraph 1.3(c)).

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 least other changes.

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.

Supplemental Information Provided by the Performance Demonstration Initiative (PDI)

Page 5 of 12 SUPPLEMENT 10 - QUALIFICATION REQUIREMENTS FOR DISSIMILAR METAL PIPING WELDS Current Requirement Proposed Change Reasoning (c) Flawed grading units shall meet the Flaw depth requirements moved to new following criteria for flaw depth, orientation, paragraph 2.4, flaw orientation requirements and type.

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 10%

Deleted, for consistency in sample sets the of the nominal pipe wall thickness. At least depth distribution is the same for detection 1/3 of the flaws, rounded to the next higher and sizing.

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 flaws remainder of the flaws shall be oriented number, shall be oriented axially. The 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 new specimen set shall include length sizing 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 above.

ten.

Supplemental Information Provided by the Performance Demonstration Initiative (PDI)

Page 6 of 12 SUPPLEMENT 10 - QUALIFICATION REQUIREMENTS FOR DISSIMILAR METAL PIPING WELDS Current Requirement Proposed Change Reasoning (c) All flaw depths shall be greater than 10%

Moved, included in new paragraph 2.4 above of the nominal pipe wall thickness. At least 1/3 after revision for consistency with detection of the flaws, rounded to the next higher whole distribution.

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 specimen Moved, included in new paragraphs 2.1, 2.3, set shall include depth sizing specimens that 2.4.

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 paragraph wholly contained within cladding and shall be 1.2(c)(1); "However, flaw depths shall exceed distributed as follows:

the nominal clad thickness when placed in cladding." Revised for clarity and included in new paragraph 2.4.

Flaw Depth Minimum Moved, included in paragraph 2.4 for

(% Wall Thickness)

Number of Flaws consistent applicability to detection and sizing 10-30%

20%

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.

Supplemental Information Provided by the Performance Demonstration Initiative (PDI)

Page 7 of 12 SUPPLEMENT 10 -QUALIFICATION REQUIREMENTS FOR DISSIMILAR METAL PIPING WELDS Current Requirement Proposed Change Reasoning (2) Depth sizing flaws shall be oriented as Included for clarity. Previously addressed by in 2.5(a).

omission (i.e., length, but not depth had a specific exclusionary statement).

2.0 CONDUCT OF PERFORMANCE 3.0 CONDUCT OF PERFORMANCE Renumbered DEMONSTRATION 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.

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 1.2.

specimens that meet the following requirements.

Supplemental Information Provided by the Performance Demonstration Initiative (PDI)

Page 8 of 12 SUPPLEMENT 10 - QUALIFICATION REQUIREMENTS FOR DISSIMILAR METAL PIPING WELDS Current Requirement Proposed Change Reasoning (1) Specimens shall be divided into grading Renumbered, moved from old paragraph units. Each grading unit shall include at least 1.2(a). Metricated. No other changes.

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-S10-1. The number of unflawed revised to reflect a change in the minimum grading units shall be at least one and a half sample set to 10 and the application of times the number of flawed grading units.

equivalent statistical false call parameters to 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 to are qualified for detection when personnel reflect the 100% detection acceptance criteria demonstrations satisfy the acceptance of procedures versus personnel and criteria of Table VIII S10-1 for both detection equipment contained in new paragraph 4.0 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 detection the detection test shall be length sized.

10 and the recent revision to Supplement 2 test.

(Reference BC 00-755).

Supplemental Information Provided by the Performance Demonstration Initiative (PDI)

Page 9 of 12 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 a "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 flaw to be sized shall be identified to the candidate. The candidate shall determine the different concepts and are not intended to be candidate. The candidate shall determine the length of the flaw in each region.

equal or interchangeable.

length of the flaw in each region.

(c) For a separate length sizing test, the Change made to ensure security of samples, (c) For a separate length sizing test, the regions of each specimen containing a flaw to consistent with the recent revision to regions of each specimen containing a flaw to be sized may be identified to the candidate.

Supplement 2 (Reference BC 00-755).

be sized shall be identified to the candidate.

The candidate shall determine the length of The candidate shall determine the length of the flaw in each region.

the flaw in each region.

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

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).

3.3 Depth Sizing Test Renumbered 2.3 Depth Sizing Test (a) For the depth sizing test, 80% of the flaws (a) The depth sizing test may be Change made to ensure security of samples, shall be sized at a specific location on the conducted separately or in conjunction consistent with the recent revision to 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 depth of the flaw in each region.

Supplemental Information Provided by the Performance Demonstration Initiative (PDI)

Page 10 of 12 SUPPLEMENT 10- QUALIFICATION REQUIREMENTS FOR DISSIMILAR METAL PIPING WELDS Current Requirement Proposed Change Reasoning (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.

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

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. (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 the change in the minimum number of flaws results of the performance demonstration and the reduction in unflawed grading units satisfy the acceptance criteria of Table VIII-from 2X to 1.5X.

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, and Moved to new paragraph 3.2(d), included personnel are qualified for length sizing the word "when" as an editorial change.

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

Supplemental Information Provided by the Performance Demonstration Initiative (PDI)

Page 11 of 12 SUPPLEMENT 10 - QUALIFICATION REQUIREMENTS FOR DISSIMILAR METAL PIPING WELDS Current Requirement Proposed Change Reasoning (b) Examination procedures, equipment, and Moved to new paragraph 3.3(c).

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 3 (a) The specimen set shall include the personnel sets (i.e., a minimum of 30 flaws) equivalent of at least three personnel sets.

is required to provide enough flaws to Successful personnel demonstrations adequately test the capabilities of the may be combined to satisfy these procedure. Combining successful requirements.

demonstrations allows a variety of examiners (b) Detectability of all flaws within the to be used to qualify the procedure.

scope of the procedure shall be Detectability of each flaw within the scope of demonstrated. Length and depth sizing the procedure is required to ensure an shall meet the requirements of paragraph acceptable personnel pass rate. The last 3.2 and 3.3.

sentence is equivalent to the previous (c) At least one successful personnel requirements and is satisfactory for demonstration has been performed.

expanding the essential variables of a (d) To qualify new values of essential previously qualified procedure.

variables, at least one personnel qualification set is required.

Supplemental Information Provided by the Performance Demonstration Initiative (PDi)

Page 12 of 12 TABLE VIII-

-1 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

5 10 0

6 6

12 1

7 6

14 1

8 7

16 2

97 18 2

10 8

2-o-15 3-2 11 9

22-- 17 3-3 12 9

24-18 3-3 13 10 26-20 4-3 14 10 2&- 21 5--3 15 11 3-- 23 5-3 16 12 3--24 6-4 17 12 3 26 6-- 4 18 13 36-27 7-4 19 13 3-- 29 7--4 20 14 40-- 30 8-5