ML030650597
| ML030650597 | |
| Person / Time | |
|---|---|
| Site: | Pilgrim |
| Issue date: | 02/27/2003 |
| From: | Riggs W Entergy Operations |
| To: | Document Control Desk, Office of Nuclear Reactor Regulation |
| References | |
| 2.03.017 | |
| Download: ML030650597 (22) | |
Text
AE
' EnteWg Entergy Nuclear Operations, Inc.
Pilgnm Station 600 Rocky Hill Road Plymouth, MA 02360 William J. Riggs Director, Nuclear Assessment February 27, 2003 U.S. Nuclear Regulatory Commission Attn: Document Control Desk Washington, DC 20555
SUBJECT:
Entergy Nuclear Operations, Inc.
Pilgrim Nuclear Power Station Docket No. 50-293 License No. DPR-35 Pilgrim Relief Request (PRR)-30, Relief from ASME Code, Section Xl, Appendix VIII, Supplement 10, "Performance Demonstration for Ultrasonic Examination Systems"
REFERENCE:
NRC Regulatory Issue Summary 2003-01, Examination of Dissimilar Metal Welds, Supplement 10 to Appendix VIII of Section XI of the ASME Code, dated January 21, 2003.
LETTER NUMBER: 2.03.017
Dear Sir or Madam:
This letter requests NRC approval of Pilgrim Relief Request (PRR) No 30, in support of refueling outage (RFO)-14. RFO -14 is scheduled to begin on April 19, 2003.
This relief request is submitted in accordance with 10 CFR 50.55a(a)(3)(i) and applies to the program required by 10 CFR 50.55a(g)(6)(ii)(C) to implement Supplement 10 to Appendix VIII of Section Xl of the ASME Code (Supplement 10).
Relief is requested to use an alternative program for implementation of Supplement 10 requirements, as presented in the attached Pilgrim Relief Request (PRR)-30. The alternative program will be implemented through the Performance Demonstration Initiative (PDI) program.
SCOPE OF THE RELIEF REQUEST The Final Rule, 64 FR 51370, dated September 22, 1999, required Pilgrim to implement a program to comply with Supplement 10 by November 22, 2002. Supplement 10 contains the qualification requirements for procedures, equipment, and personnel involved with examining dissimilar metal (DSM) welds using ultrasonic techniques. This scope is commonly referred as performance based criteria to improve the ability of an examiner to detect and characterize flaws during examination of components to provide more reliable examination results.
203017 "oto
Entergy Nuclear Operations, Inc. Letter Number: 2.03.017 Pilgrim Nuclear Power Station Page 2 The industry has implemented a PDI program and has developed an alternative program to implement Supplement 10. The alternative program is based on forthcoming ASME Code and was generated from a PDI model prepared by EPRI. The alternative program has been submitted to the ASME Code for consideration and as of December 2002 had been approved by the NDE Subcommittee. Pilgrim has been a participant in the industry-sponsored program through Nuclear Energy Institute and EPRI. Pilgrim will implement the alternative program when approved by the applicable ASME and regulatory actions.
The inability to meet thel0 CFR 50.55a(g)(6)(ii)(C) required schedule of November 22, 2002 to have a Supplement 10 program in place has not impacted safe operation of Pilgrim because the program is intended for use during an outage for DSM weld examinations. RFO-1 4 will be the first outage after November 22, 2002 and Pilgrim plans to follow the alternative program for DSM weld examinations described in PRR-30 during RFO-14. As described in NRC RIS 2003 01 (Reference) until regulatory compliance is achieved, any system operability issues arising from the inability to comply with Appendix VIII Supplement 10 will be addressed consistent with Generic Letter 91-18.
Pilgrim will submit additional relief requests for NRC approval if the required examination coverage and/or flaw characterizations are not achieved during the outage in accordance with the alternative program. Additional relief requests, if required, would be submitted within 90 days of restart from RFO-1 4, along with the ISI examinations results report.
The proposed alternative program described in the attached PRR-30 follows the scope of Supplement 10, with the enhancements, clarifications, and refinements as approved by the ASME Code NDE Subcommittee and provides acceptable level of quality and safety as required by 10 CFR 50.55a(a)(3)(i). Approval of this relief request is necessary for Pilgrim to comply with 10 CFR 50.55a(g)(6)(ii)(C) and approval is requested by April 19,2003.
If you have any questions regarding the information contained in this letter, please contact Bryan Ford at (508) 830-8403.
Sincerely, iflliam J. iggs
Attachment:
Pilgrim Relief Request PRR-30 (18 pages) cc:
Mr. Travis Tate, Project Manager U.S. NRC, Region 1 Office of Nuclear Reactor Regulation 475 Allendale Road Mail Stop: 0-88-1 King of Prussia, PA 19406 U. S. Nuclear Regulatory Commission 1 White Flint North 11555 Rockville Pike Senior Resident Inspector Rockville, MD 20852 Pilgrim Nuclear Power Station 203017
Attachment to Letter 2.03.017 Pilgrim Relief Request PRR-30
PILGRIM RELIEF REQUEST NO. PRR-30 THIRD 10-YEAR INSERVICE INSPECTION INTERVAL SYSTEM/COMPONENT (S) FOR WHICH RELIEF IS REQUESTED Pressure Retaining Piping Welds subject to examination using procedures, personnel, and equipment qualified to ASME Section Xl, Appendix Viii, Supplement 10 criteria.
CODE REQUIREMENTS 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 1.1 (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.
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 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.
RELIEF REQUESTED 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.
A copy of the proposed revision to Supplement 10 is attached. It identifies the proposed alternatives and allows them to be viewed in context. It also identifies additional clarifications and enhancements for information. It has been submitted to the ASME Code for consideration and as of September 2002 has been approved by the NDE Subcommittee.
BASIS FOR RELIEF Item 1 - The proposed alternative to Paragraph 1.1(b) is:
"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.
Item 2 - The proposed alternative to Paragraph 1.1 (d) is:
"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). 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.
SEx....-- Mechanical fattgue crack Sin Base material Item 3 -The proposed alternative to Paragraph 1.1 (d)(1) is:
"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) is:
"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 - Table VIII-S10-1 provides a statistically based ratio between the number of unflawed grading units and the number of flawed grading units. The proposed alternative reduces the ratio to 1.5 times. This reduces 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
$10-1.
Item 5 - The proposed alternative to the flaw distribution requirements of Paragraph 1.2(c)(1) (detection) and 1.3(c) (length) is to use the Paragraph 1.4(b) (depth) distribution table (see below) for all qualifications.
Flaw Depth Minimum
(% Wall Thickness) Number of Flaws 10-30% 20%
31-60% 20%
61-100% 20%
Technical Basis - The proposed alternative uses the depth sizing distribution for both detection and depth sizing because it provides for a better distribution of flaw sizes within the test set. This distribution allows candidates to perform detection, length, and
Depth-sizing demonstrations simultaneously utilizing the same test set. The requirement that at least 75% of the flaws shall be in the range of 10 to 60% of wall thickness provides an overall distribution tolerance. 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 is:
"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"."
This proposed alternative is applicable to PWRs and therefore, not applicable to Pilgrim.
Items 7 and 8 - The proposed alternatives to Paragraph 2.2(b) and 2.2(c) is:
"... 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) is:
"... 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.
Item 11 - The proposed alternative modifies the acceptance criteria of Table VIII-S2-1 as follows:
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 10 0 6 12 7 6 14 1 8 7 16 2' 9 7 18 2 10 8 2 15 3-- 2 11 9 27-- 17 3-3 12 9 24- 18 a- 3 13 10 26-20 4-3 14 10 27&- 21 5-3 15 11 3e-- 23 5-3 16 12 32-24 6--.4 17 12 34- 26 6-4 i8 13 36-- 27 4 19 13 3 29 7-4 20 14 40-30 8-5 Technical Basis - The proposed alternative is identified as new Table S1 0-1 above. It was modified to reflect the reduced number of unflawed grading units and allowable false calls. As a part of ongoing Code activities, PNNL has reviewed the statistical significance of these revisions and offered the revised Table S10-1.
ALTERNATIVE EXAMINATION In lieu of the requirements of ASME Section XI, 1995 Edition, 1996 Addenda, Appendix VIII, Supplement 10, the proposed alternative shall be used. The proposed alternative is described in the enclosure.
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 X1, Appendix VIII, Supplement 10 requirements. Compliance with the proposed alternatives will provide an adequate level of quality and safety for examination of the affected welds.
IMPLEMENTATION SCHEDULE The alternative program will be applicable for the 3rd ISI interval.
Enclosure to Attachment Supplement 10 - Qualification Requirements for Dissimilar Metal Piping Welds
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 resistant Supplement 10 and the recent revision to clad (CRC) applied to mitigate Intergranular Supplement 2 (Reference BC 00-755).
Stress Corrosion Cracking (IGSCC). Note, an additional 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 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 limitations), weld joint configuration, access limitations).
The same specimens may be used to The 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 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 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 (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 minimum and maximum pipe diameters minimum and maximum pipe diameters pipe diameter tolerance provides and thicknesses for which the examination and thicknesses for which the examination consistency between Supplement 10 and procedure is applicable. Pipe diameters procedure is applicable. Pipe diameters the recent revision to Supplement 2 within a range of 0.9 to 1.5 times a nominal within a range of 1/2 in. (13 mm) of the (Reference BC 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
SUPPLEMENT 10 - QUALIFICATION REQUIREMENTS FOR DISSIMILAR METAL PIPING WELDS Current Requirement Proposed Change Reasoning considered to be flat. When a range of in. (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 (d) The specimen set shall include Renumbered, changed "condition" to examples of the following fabrication examples of the following fabrication "conditions" condition: 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 OD qualifications be conducted external tapers). and safe end external tapers for outside independently (Note, new paragraph 2.0 surface 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 examinations), designed to accommodate specific Qualification requirements shall be satisfied limitations stated in the scope of the separately for outside surface and inside examination procedure.").
surface examinations.
(d) All flaws in the specimen set shall be Deleted this requirement, because new cracks. paragraph 2.3 below provides for the use of "alternative flaws" in lieu of cracks.
(1) At least 50% of the cracks shall be 2.2 Flaw Location. At least 80% of the Renumbered and re-titled. Flaw location in austenitic material. At least 50% flaws shall be contained wholly in weld or percentages redistributed because field of the cracks in austenitic material buttering material. At least one and a experience indicates that flaws contained in shall be contained wholly in weld or maximum of 10% of the flaws shall be in weld or buttering material are probable and buttering material. At least 10% of ferritic base material. At least one and a represent the more stringent ultrasonic the cracks shall be in ferritic maximum of 10% of the flaws shall be in detection scenario.
material. The remainder of the austenitic base material.
cracks may be in either austenitic or ferritic material.
SUPPLEMENT 10 - QUALIFICATION REQUIREMENTS FOR DISSIMILAR METAL PIPING WELDS Current Requirement Proposed Change Reasoning (2) At least 50% of the cracks in austenitic 2.3 Flaw Type. Renumbered and re-titled. Alternative base material shall be either IGSCC or (a) At least 60% of the flaws shall be flaws are required for placing axial flaws in thermal fatigue cracks. At least 50% of the cracks, 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. Alternative The 40% limit on alternative flaws is flaw mechanisms shall have a tip width of needed to support the requirement for up to less than or equal to 0.002 in. (.05 mm). 70% axial flaws. Metricated (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))
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.
SUPPLEMENT 10 - QUALIFICATION REQUIREMENTS FOR DISSIMILAR METAL PIPING WELDS Current Requirement Proposed Change Reasoning 1.2 Detection Specimens. The specimen Renumbered and re-titled and moved to set shall include detection specimens that paragraph 3.1(a). No other changes meet 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, orientation, paragraph 2.4, flaw orientation and type. requirements moved to new paragraph 2.5, flaw type requirements moved to new paragraph 2.3, "Flaw Type".
(1) All flaw depths shall be greater than Deleted, for consistency in sample sets the, 10% of the nominal pipe wall depth distribution is the same for detection thickness. At least 1/3 of the flaws, and sizing.
rounded to the next 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.
SUPPLEMENT 10 - QUALIFICATION REQUIREMENTS FOR DISSIMILAR METAL PIPING WELDS Current Requirement Proposed Change Reasoning (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 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 Moved, included in new paragraph 2.1 be ten.
SUPPLEMENT 10 - QUALIFICATION REQUIREMENTS FOR DISSIMILAR METAL PIPING WELDS Current Requirement Proposed Change Reasoning (b) Flaws in the sample set shall not be Moved, potential conflict with old paragraph wholly contained within cladding and shall 1.2(c)(1); "However, flaw depths shall be distributed as follows: exceed the nominal clad thickness when placed in cladding." Revised for clarity and included in new paragraph 2.4 Moved, included in paragraph 2.4 for Flaw Depth Minimum consistent applicability to detection and
(% Wall Thickness) Number of Flaws sizing samples.
10-30% 20%
31-60% 20%
61-100% 20%
The remaining flaws shall be in any of the above categories.
(b) Sizing Specimen sets shall meet the Added for clarity following requirements.
(1) 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 PERFORMANCE 3.0 CONDUCT OF PERFORMANCE Renumbered DEMONSTRATION DEMONSTRATION The specimen inside surface and For qualifications from the outside surface, Differentiate between qualifications identification shall be concealed from the 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 flaw Divulgence of particular specimen results location and specimen identification shall or candidate viewing of unmasked be obscured to maintain a "blind test". All specimens after the performance examinations shall be completed prior to demonstration is prohibited. grading the results and presenting the results to the candidate. Divulgence of particular specimen results or candidate
SUPPLEMENT 10 - QUALIFICATION REQUIREMENTS FOR DISSIMILAR METAL PIPING WELDS Current Requirement Proposed Change Reasoning 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 Renumbered, moved from old paragraph detection specimens that meet the 1.2.
following 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-S10-1. 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 units. 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.
SUPPLEMENT 10 - QUALIFICATION REQUIREMENTS FOR DISSIMILAR METAL PIPING WELDS Current Requirement Proposed Change Reasoning (b) Examination equipment and personnel Moved from old paragraph 3.1. Modified to are qualified for detection when personnel 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 (a) Each reported circumferential flaw in the Provides consistency between Supplement' conducted separately or in conjunction with detection test shall be length sized. 10 and the recent revision to Supplement 2 the detection test. (Reference BC 00-755).
SUPPLEMENT 10 - QUALIFICATION REQUIREMENTS FOR DISSIMILAR METAL PIPING WELDS Current Requirement Proposed Change Reasoning (b) When the length-sizing test is Change made to ensure security of (b) When the length-sizing test is conducted in conjunction with the detection samples, consistent with the recent revision conducted in conjunction with the detection test, and less than ten circumferential flaws to Supplement 2 (Reference BC 00-755).
test, and less than ten circumferential flaws are detected, additional specimens shall be are detected, additional specimens shall be provided to the candidate such that at least Note, length and depth sizing use the term provided to the candidate such that at least ten flaws are sized. The regions containing "regions" while detection uses the term ten flaws are sized. The regions containing a flaw to be sized may be identified to the "grading units". The two terms define a flaw to be sized shall be identified to the candidate. The candidate shall determine different concepts and are not intended to candidate. The candidate shall determine the length of the flaw in each region. be equal or interchangeable.
the length of the flaw in each region.
(c) For a separate length-sizing test, the Change made to ensure security of (c) For a separate length-sizing test, the regions of each specimen containing a flaw samples, consistent with the recent revision regions of each specimen containing a flaw to be sized may be identified to the to Supplement 2 (Reference BC 00-755).
to be sized shall be identified to the candidate. The candidate shall determine candidate. The candidate shall determine the length of the flaw in each region.
the length of the flaw in each region.
(d) Examination procedures, equipment, Moved from old paragraph 3.2(a) includes and personnel are qualified for length sizing inclusion of "when" as an editorial change.
when the RMS error of the flaw length Metricated.
measurements, as compared to the true flaw lengths, 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 (a) The depth-sizing test may be conducted Change made to ensure security of flaws shall be sized at a specific location on separately or in conjunction with the samples, consistent with the recent revision the surface of the specimen identified to the detection test. For a separate depth-sizing to Supplement 2 (Reference BC 00-755).
candidate. 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.
(b) For the remaining flaws, the regions of (b) When the depth-sizing test is conducted Change made to be consistent with the each specimen containing a flaw to be in conjunction with the detection test, and recent revision to Supplement 2 (Reference
SUPPLEMENT 10 - QUALIFICATION REQUIREMENTS FOR DISSIMILAR METAL PIPING WELDS Current Requirement Proposed Change Reasoning sized shall be identified to the candidate, less than ten flaws are detected, additional BC 00-755).
The candidate shall determine the specimens shall be provided to the maximum depth of the flaw in each region. candidate such that at least ten flaws are Changes made to ensure security of sized. The regions of each specimen samples, consistent with the recent revision containing a flaw to be sized may be to Supplement 2 (Reference BC 00-755).
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-$2-1 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 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
SUPPLEMENT 10 - QUALIFICATION REQUIREMENTS FOR DISSIMILAR METAL PIPING WELDS Current Requirement. Proposed Change Reasonin 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 requirements. procedure. Combining successful (b) Detectability of all flaws within the scope demonstrations allows a variety of of the procedure shall be demonstrated, examiners to be used to qualify the Length and depth sizing shall meet the procedure. Detectability of each flaw within requirements of paragraph 3.2 and 3.3. the scope of the procedure is required to (c) At least one successful personnel ensure an acceptable personnel pass rate.
demonstration has been performed. The last sentence is equivalent to the (d) To qualify new values of essential previous requirements and is satisfactory variables, at least one personnel for expanding the essential variables of a qualification set is required. previously qualified procedure
SUPPLEMENT 10 - QUALIFICATION REQUIREMENTS FOR DISSIMILAR METAL PIPING WELDS Current Requirement Proposed Change Reasoning TABLE VIII-SI-" 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 55 10 o 6 6 121 7 6 14 I 8 7 16 2 9 7 18 2 10 8 2- 15 2 11 9 22-- 17 3- 3 12 9 24- 18 --- 3 13 10 26- 20 4-3 14 10 2-8--21 5--3 15 11 36-23 5--3 16 12 3*-24 6--. 4 17 12 34- 26 6--4 i1 13 36-27 7-4 19 13 3e- 29 7-4 20 14 40-30 -- 5