ML032550245
| ML032550245 | |
| Person / Time | |
|---|---|
| Site: | Calvert Cliffs  |
| Issue date: | 09/09/2003 |
| From: | Vanderheyden G Constellation Energy Group |
| To: | Document Control Desk, Office of Nuclear Reactor Regulation |
| References | |
| Download: ML032550245 (20) | |
Text
6 .
George Vanderheyden 1650 Calvert Cliffs Parkway Vice President Lusby, Maryland 20657 Calvert Cliffs Nuclear Power Plant 410 495-4455 Constellation Generation Group, LLC 410 495-3500 Fax Constellation Energy Group September 9, 2003 U. S. Nuclear Regulatory Commission Washington, DC 20555 ATTENTION: Document Control Desk
SUBJECT:
Calvert Cliffs Nuclear Power Plant Unit Nos. 1 & 2; Docket Nos. 50-317 & 50-318 ASME Section XI Relief Request to Use Alternative Techniques for Examining Dissimilar Metal Welds
REFERENCE:
(a) Letter from Ms. M. Gamberoni (NRC) to Mr. C. H. Cruse (BGE), dated April 5, 2000, Safety Evaluation of Proposed Alternate American Society of Mechanical Engineers Boiler and Pressure Vessel Code (ASME Code)
Section XI, 1998 Edition for the Third 10-Year Inspection Interval -
Calvert Cliffs Nuclear Power Plant, Unit Nos. 1 and 2 (TAC Nos. MA4647 and MA4648 Pursuant to 10 CFR 50.55a(a)(3)(i), Calvert Cliffs Nuclear Power Plant, Inc. (CCNPP) hereby proposes alternatives to the American Society of Mechanical Engineers (ASME) Boiler and Pressure Vessel Code (Code) requirements concerning the pressure retaining welds subject to examination using ASME Section XI, Appendix VIII, Supplement 10 criteria for the Third Ten-Year Inservice Inspection interval.
Paragraph 50.55a(a)(3)(i) allows the use of alternatives to the requirements of Paragraph 50.55a(g), that provide an acceptable level of quality and safety, when authorized by the Director of the Office of Nuclear Reactor Regulation.
The Third Ten-Year Inservice Inspection Program Plan for Calvert Cliffs Units 1 and 2 meets the requirements of the 1998 Edition, no Addenda of Section M of the ASME Code (except for Subsections IWE and IWL), as approved by Nuclear Regulatory Commission letter (Reference a).
RELIEF REQUEST Supplement 10 to Appendix VIII, "Performance Demonstration for Ultrasonic Examination Systems," of Section XI of the 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, CCNPP proposes to use the dissimilar metal weld criteria of the Performance Demonstration Initiative (PDI) Program. Similar relief requests have been previously approved for other
( 1,
Document Control Desk September 9, 2003 Page 2 licensees including Exelon Nuclear on July 16, 2003, and Entergy Nuclear Generation Company on May 8, 2003. The detailed relief request and the justification are provided in Attachments (1) and (2).
SAFETY COMMiTTEE REVIEW The proposed relief request has been reviewed by our Plant Operations and Safety Review Committee, and they have concluded that the proposed alternatives provide an acceptable level of quality and safety.
SCHEDULE We plan to use the PDI Program criteria in the upcoming Calvert Cliffs Unit I Spring 2004 refueling outage (currently scheduled to begin in early April 2004). We request that the Nuclear Regulatory Commission review and approve our proposed alternative for use during this outage.
Should you have questions regarding this matter, we will be pleased to discuss them with you.
Very truly yours, I for George Vanderheyden Vice President - Calvert Cliffs Nuclear Power Plant GV/GT/bjd Attachments: (1) Relief Request To Use Alternative Techniques for Examining Dissimilar Metal Welds (2) Supplement 10 - Qualification Requirements for Dissimilar Metal Piping Welds cc: J. Petro, Esquire - H. J. Miller, NRC J. E. Silberg, Esquire Resident Inspector, NRC Director, Project Directorate I-1, NRC R. I. McLean, DNR G. S. Vissing, NRC
s ATTACHMENT (1)
RELIEF REQUEST TO USE ALTERNATIVE TECHNIQUES FOR EXAMINING DISSIMILAR METAL WELDS Calvert Cliffs Nuclear Power Plant, Inc.
September 9,2003
1; ATTACHMENT (1)
RELIEF REQUEST TO USE ALTERNATIVE TECHNIQUES FOR EXAMINING DISSIMILAR METAL WELDS COMPONENT FOR WHICH RELIEF IS REQUESTED:
Dissimilar metal piping welds subject to ultrasonic examination using procedures, personnel, and equipment qualified to the American Society of Mechanical Engineers (ASME) Code,Section XI, Appendix VIII, Supplement 10, "Qualification Requirements for Dissimilar Metal Piping Welds."
CODE REQUIREMENTS FOR WHICH RELIEF IS REQUESTED:
The 1998 Edition no Addenda of ASME Section Xl Appendix VIII, Supplement 10 identify the following specific requirements that are included in this relief request.
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.I(dXl) 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 - Paragraphs 1.2(cX) 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 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.
PROPOSED ALTERNATIVE:
Attachment (2) identifies Supplement 10 current requirements and the proposed alternatives, which allows them to be viewed in context. It also identifies additional clarifications and enhancements for I
ATTACHMENT (1)
RELIEF REQUEST TO USE ALTERNATIVE TECHNIQUES FOR EXAMINING DISSIMILAR METAL WELDS information. It has been approved by the Board on Nuclear Codes and Standards (BC03-81) along with an implementing Code Case (N-695).
SUPPORTING INFORMATION:
Item 1 - The proposed alternative to Paragraph 1.l(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 inch (13 mm) of the nominal diameter shall be considered equivalent. Pipe diameters larger than 24 inches (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. his 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 intergranular stress corrosion cracking (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 service induced flaws. Alternative flaw mechanisms shall have a tip width of less than or equal to 0.002 inch (.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.
- 2
ATTACHMENT (1)
RELIEF REQUEST TO USE ALTERNATIVE TECHNIQUES FOR EXAMINING DISSIMILAR METAL WELDS Item 3 - The proposed alternative to Paragraph 1.l(dX l) 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. 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.
Item 4 - The proposed alternative to Paragraph 1.2(b) states:
"Detection sets shall be selected from Table VIII-SIO-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 VIII-S1I-l 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-S1O-1.
Item 5 - The proposed alternative to the flaw distribution requirements of Paragraph 1.2(cXl) (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.
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ATTACHMENT (1)
RELIEF REQUEST TO USE ALTERNATIVE TECHNIQUES FOR EXAMINING DISSIMILAR METAL WELDS 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 (PWR) nozzle to safe end welds] impractical. The proposed alternative differentiates between inside diameter (ID) and outside diameter (OD) scanning surfaces, requires that they be conducted separately, and 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.
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ATTACHMENT (1)
RELIEF REQUEST TO USE ALTERNATIVE TECHNIQUES FOR EXAMNING DISSIMILAR METAL WELDS Item 11 - The proposed alternative modifies the acceptance criteria of Table VIII-S2-1 as follows:
TABLE VI-S' PERFORMANCE DEMONSTRATION DETECTION TEST ACCEPTANCE CRITERIA Detection Test False Call Test Acceptance Criteria Acceptance Criteria No. of Flawed Minimum No. of Unflawed Maximum No. of Flawe Detection N a.of Uniwd Number of False Grading Units Criteria raag Unitslls
$ 4 4.0 a 4 4 4.3 4.
.7 6 4-4 4.
C4.6 a 0 ~~~~~743 3 10 8 20 15 2 11 9 22 17 a 3 12 9 24 18 3 13 10 2420 43 14 10 28 21 5-3 15 11 3.023 $3 16 12 32 24 64 17 12 34 26 6 4 18 13 36 27 4 19 13 38 29 7 4 20 14 4030 85 Technical Basis - The proposed alternative is identified as new Table VIII-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 North West National Laboratory has reviewed the statistical significance of these revisions and offered the revised Table VIII-S2-1.
CONCLUSION:
Calvert Cliffs believes the proposed alternatives to Supplement 10, as administered by the Electric Power Research Institute-Performance Demonstration Initiative Program, provide an acceptable level of quality and safety.
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ATTACHMENT ()
SUPPLEMENT 10 - QUALIFICATION REQUIREMENTS FOR DISSIMILAR METAL PIPING WELDS Calvert Cliffs Nuclear Power Plant, Inc.
September 9, 2003
ATrACHMENT (2)
SUPPLEMENT 10 - QUALIFICATION REQUIREMENTS FOR DISSIMILAR METAL PIPING WELDS Current Requirement Proposed Change Reasoning 1.0 SCOPE Supplement 10 is applicable to dissimilar metal A scope statement provides added clarity piping welds examined from either the inside or regarding the applicable range of each outside surface. Supplement 10 is not individual Supplement. The exclusion of CRC applicable to piping welds containing provides consistency between Supplement 10 supplemental corrosion resistant clad (CRC) and the recent revision to Supplement 2 applied to mitigate Intergranular Stress (Reference BC 00-755). Note, an additional Corrosion Cracking (IGSCC). change identifying CRC 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 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 demonstrate same specimens may be used to demonstrate both detection and sizing qualification. both detection and sizing 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 set New, changed minimum number of flaws to 10 shall be ten. 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 interfere minimize spurious reflections that may interfere with the interpretation process. with the interpretation process.
I
ATTACHMENT (2)
SUPPLEMENT 10 - QUALIFICATION REQUIREMENTS FOR DISSIMILAR METAL PIPING WELDS Current Requirement Proposed Change Reasoning (b) The specimen set shall include the minimum (c) The specimen set shall include the minimum Renumbered, metricated, the change in pipe and maximum pipe diameters and thicknesses and maximum pipe diameters and thicknesses diameter tolerance provides consistency for which the examination procedure is for which the examination procedure is between Supplement 10 and the recent revision applicable. Pipe diameters within a range of applicable. Pipe diameters within a range of to Supplement 2. (Reference BC 00-755) 0.9 to 1.5 times a nominal diameter shall be 1/2 inch (13 mm) of the nominal diameter shall considered equivalent. Pipe diameters larger be considered equivalent. Pipe diameters than 24 inches shall be considered to be flat. larger than 24 inches (610 mm) shall be When a range of thicknesses is to be considered to be flat. When a range of examined, a thickness tolerance +25% is thicknesses is to be examined, a thickness acceptable. tolerance of +25% is acceptable.
(c) The specimen set shall include examples of (d) The specimen set shall include examples of Renumbered, changed "condition" to the following fabrication condition: 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 or normally require discrimination from flaws material conditions rather than geometric weld root conditions, cladding, weld buttering, (e.g., counterbore or weld root conditions, conditions. Weld repair areas were added as a remnants of previous welds, adjacent welds in cladding, weld buttering, remnants of previous result of recent field experiences.
close proximity); 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 due (e.g., weld crowns, diametrical shrink, single- surface limitations. Requires that ID and OD to nozzle and safe end external tapers). side access due to nozzle and safe end qualifications be conducted independently external tapers for outside surface {Note, new paragraph 2.0 (identical to old examinations; and internal tapers, exposed paragraph 1.0) provides for alternatives when weld roots, and cladding conditions for inside "a set of specimens is designed to surface examinations). Qualification accommodate specific limitations stated in the requirements shall be satisfied separately for scope of the examination procedure.")
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.
2
ATrACHMENT (2)
I 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 flaws Renumbered and re-titled. Flaw location austenitic material. At least 50% of the cracks shall be contained wholly in weld or buttering percentages redistributed because field in austenitic material shall be contained wholly material. At least one and a maximum of 10% experience indicates that flaws contained in in weld or buttering material. At least 10% of of the flaws shall be in ferritic base material. At weld or buttering material are probable and the cracks shall be in ferritic material. The least one and a maximum of 10% of the flaws represent the more stringent ultrasonic remainder of the cracks may be in either shall be in austenitic base material. detection scenario.
austenitic or ferritic material.
(2) At least 50% of the cracks in austenitic base 2.3 Flaw Type. Renumbered and re-titled. Alternative flaws are material shall be either IGSCC or thermal (a)At least 60% of the flaws shall be cracks; required for placing axial flaws in the HAZ of fatigue cracks. At least 50% of the cracks in the remainder shall be alternative flaws. the weld and other areas where implantation of ferritic material shall be mechanically or Seinswith IGSCC shall be used when a crack produces metallurgical conditions that thermally induced fatigue cracks. available. AlteSiative flaws, if used, shall result in an unrealistic ultrasonic response.
fawsif ued, hallThis avaiableAltrnatve is consistent with the recent revision to provide crack-like reflective characteristics and shall be limited to the case where implantation upplement 2 (Reference BC 00-755).
of cracks produces spurious reflectors that are The 40% limit on alternative flaws is needed to uncharacteristic of service-induced flaws. support the requirement for up to 70% axial Alternative flaw mechanisms shall have a tip flaws. Metricated.
width of less than or equal to 0.002 inch
(.05 mm).
(3) At least 50% of the cracks shall be (b)At least 50% of the flaws shall be coincident Renumbered. Due to inclusion of "alternative coincident with areas described in (c) above. with areas described in 2.1(d) above. flaws," use of "cracks" is no longer appropriate.
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ATrACHMENT (2)
SUPPLEMENT 10 - QUALIFICATION REQUIREMENTS FOR DISSIMILAR METAL PIPING WELDS Current Requirement Proposed Change Reasoning 2.4 Flaw Depth. All flaw depths shall be greater Moved from old paragraph 1.3(c) and 1.4 and than 10% of the nominal pipe wall thickness. re-titled. Consistency between detection and Flaw depths shall exceed the nominal clad sizing specimen set requirements (e.g., 20%
thickness when placed in cladding. Flaws in vs. 1/3 flaw depth increments, e.g., original the sample set shall be distributed as follows: paragraph 1.3(c)).
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 the paragraph 3.1(a). No other changes.
following requirements.
(a) Specimens shall be divided into grading Renumbered to paragraph 3.1(a)(1). No other units. Each grading unit shall include at least changes.
3 inches of weld length. If a grading unit is designed to be unflawed, at least 1 inch 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 Table Moved to new paragraph 3.1(a)(2).
Vil-S2- 1. The number of unflawed grading units shall be at least twice the number of flawed grading units.
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AITACHMENT (2)
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, and paragraph 2.4, flaw orientation requirements 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% of Deleted, for consistency in sample sets the the nominal pipe wall thickness. At least 1/3 of depth distribution is the same for detection and the flaws, rounded to the next higher whole sizing.
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 the 2.5 Flaw Orientation. Note this distribution is applicable for detection flaws, rounded to the next higher whole (a) For other than length sizing specimens, at and depth sizing. Paragraph 2.5(b)(1) requires number, shall be oriented axially. The least 30% and no more than 70% of the flaws, that all length-sizing flaws be oriented remainder of the flaws shall be oriented rounded to the next higher whole number, shall circumferentially.
circumferentially. be oriented axially. The remainder of the flaws shall be oriented circumferentially.
1.3 Length-Sizing Specimens. The specimen Renumbered and re-titled and moved to new set shall include length-sizing specimens that paragraph 3.2.
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 ten. Moved, included in new paragraph 2.1 above.
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ATTACHMENT (2)
SUPPLEMENT 10 - QUALIFICATION REQUIREMENTS FOR DISSIMILAR METAL PIPING WELDS Current Requirement Proposed Change Reasoning (c) All flaw depths shall be greater than 10% of Moved, included in new paragraph 2.4 above the nominal pipe wall thickness. At least 1/3 of after revision for consistency with detection 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. D (a)The minimum number of flaws shall be ten. Moved, included in new paragraph 2.1.
(b)Flaws in the sample set shall not be wholly Moved, potential conflict with old paragraph 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 consistent
(% Wall Thickness) Number of Flaws applicability to detection and 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)All length-sizing flaws shall be oriented Moved from old paragraph 1.3(a).
circumferentially.
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ATTACHMENT (2)
SUPPLEMENT 10 - QUALIFICATION REQUIREMENTS FOR DISSIMILAR METAL PIPING WELDS Current Requirement Proposed Change Reasoning (2) Depth sizing flaws shall be oriented as in Included for clarity. Previously addressed by 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 identification For qualifications from the outside surface, the Differentiate between qualifications conducted shall be concealed from the candidate. All specimen inside surface and identification shall from the outside and inside surface.
examinations shall be completed prior to be concealed from the candidate. When grading the results and presenting the results to qualifications are performed from the inside the candidate. Divulgence of particular surface, the flaw location and specimen specimen results or candidate viewing of identification shall be obscured to maintain a unmasked specimens after the performance "blind test." All examinations shall be demonstration is prohibited. 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 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.
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ATTACHMENT (2) il 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 inches (76 mm) of weld length. If a grading unit is designed to be unflawed, at least 1 inch (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 Table Moved from old paragraph 1.2(b). Table VIII-SIO-1. The number of unflawed grading revised to reflect a change in the minimum units shall be at least one and a half times the sample set to 10 and the application of 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 be Moved from old paragraph 2.1.
randomly mixed.
(b)Examination equipment and personnel are Moved from old paragraph 3.1.
qualified for detection when personnel Modified to reflect the 100% detection demonstrations satisfy the acceptance criteria acceptance criteria of procedures versus of Table Vill S10-1 for both detection and false personnel and equipment contained in new calls. paragraph 4.0 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 the Provides consistency between Supplement 10 separately or in conjunction with the detection detection test shall be length sized. and the recent revision to Supplement 2 test. (Reference BC 00-755).
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ATTACHMENT (2)
SUPPLEMENT 10 - QUALIFICATION REQUIREMENTS FOR DISSIMILAR METAL PIPING WELDS Current Requirement Proposed Change Reasoning (b) When the length-sizing test is conducted in (b) When the length-sizing test is conducted in Change made to ensure security of samples, conjunction with the detection test, and less conjunction with the detection test, and less consistent with the recent revision to than ten circumferential flaws are detected, than ten circumferential flaws are detected, Supplement 2 (Reference BC 00-755).
additional specimens shall be provided to the additional specimens shall be provided to the Note, length and depth sizing use the term candidate such that at least ten flaws are sized. candidate such that at least ten flaws are sized. tregions" while detection uses the term The regions containing a flaw to be sized shall The regions containing a flaw to be sized may 'grading units." The two terms define different be identified to the candidate. The candidate be identified to the candidate. The candidate concepts and are not intended to be equal or shall determine the length of the flaw in each shall determine the length of the flaw in each interchangeable.
region. region.
(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 to regions of each specimen containing a flaw to consistent with the recent revision to be sized shall be identified to the candidate. be sized may be identified to the candidate. Supplement 2 (Reference BC 00-755).
The candidate shall determine the length of the The candidate shall determine the length of the flaw in each region. 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 measurements, as compared to the true flaw Metricated.
lengths, is less than or equal to 0.75 inch (19 mm).
2.3 Depth Sizing Test 3.3 Depth Sizing Test Renumbered (a) For the depth sizing test, 80% of the flaws (a) The depth sizing test may be conducted Change made to ensure security of samples, shall be sized at a specific location on the separately or in conjunction with the detection consistent with the recent revision to surface of the specimen identified to the test. For a separate depth sizing test, the Supplement 2 (Reference BC 00-755).
candidate. 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.
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ATrACHMENT (2)
SUPPLEMENT 10 - QUALIFICATION REQUIREMENTS FOR DISSIMILAR METAL PIPING WELDS Current Requirement Proposed Change Reasoning (b) For the remaining flaws, the regions of each (b)When the depth sizing test is conducted in Change made to be consistent with the recent specimen containing a flaw to be sized shall be conjunction with the detection test, and less revision to Supplement 2 (Reference BC 00-identified to the candidate. The candidate shall than ten flaws are detected, additional 755).
determine the maximum depth of the flaw in specimens shall be provided to the candidate Changes made to ensure security of samples, each region. such that at least ten flaws are sized. The consistent with the recent revision to regions of each specimen containing a flaw to Supplement 2 (Reference BC 00-755).
be sized may be identified to the candidate. Supe nt2(frncBC075)
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).
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 inch (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 SI0-1 from S2-1 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 from 2X to 1.5X.
Vil-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 word personnel are qualified for length sizing the "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 inches.
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ATTACHMENT (2)
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 inches.
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) is equivalent of at least three personnel sets. required to provide enough flaws to adequately test the capabilities of the procedure.
Successful personnel demonstrations may be Combining successful demonstrations allows Ia combined to satisfy these requirements.tethecpblisofhercdu.
vanety of examiners to be used to qualify the (b) Detectability of all flaws within the scope of procedure. Detectability of each flaw within the the procedure shall be demonstrated. Length scope of the procedure is required to ensure an and depth sizing shall meet the requirements of acceptable personnel pass rate. The last paragraph 3.2 and 3.3. sentence is equivalent to the previous (c) At least one successful personnel requirements and is satisfactory for expanding demonstration has been performed. the essential variables of a previously qualified procedure.
(d) To qualify new values of essential variables, at least one personnel qualification set is required.
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