ML041040587
| ML041040587 | |
| Person / Time | |
|---|---|
| Site: | Palo Verde  |
| Issue date: | 04/05/2004 |
| From: | Mauldin D Arizona Public Service Co |
| To: | Document Control Desk, Office of Nuclear Reactor Regulation |
| References | |
| 102-05079-CDM/SAB/RJR | |
| Download: ML041040587 (23) | |
Text
David Mauldin 10 CFR 50.55a Vice President Mail Station 7605 Palo Verde Nuclear Nuclear Engineering TEL (623) 393-5553 P.O. Box 52034 Generating Station and Support FAX (623) 393-6077 Phoenix, AZ 85072-2034 102-05079-CDM/SAB/RJR April 5, 2004 U.S. Nuclear Regulatory Commission ATTN: Document Control Desk Washington, DC 20555
Dear Sirs:
Subject:
Palo Verde Nuclear Generating Station (PVNGS)
Units 1, 2, and 3 Docket Nos. STN 50-528, 50-529 and 50-530 License Nos. NPF-41, NPF-51 and NPF-74 Second Ten-Year Interval Inservice Inspection Program Relief Request No. 26 - Relief from ASME Code, Section Xl, Appendix Vil, Supplement 10 Supplement 10 to ASME Section Xl, Appendix VIII, "Performance Demonstration for Ultrasonic Examination Systems," contains qualification requirements for procedures, equipment, and personnel involved with examining dissimilar metal welds using ultrasonic techniques. Pursuant to 10 CFR 50.55a( a)( 3)( i), Arizona Public Service Co.
(APS) requests NRC approval to use an alternative in lieu of certain of these requirements.
Approval is requested to use a technical alternative developed by the Performance Demonstration Initiative (PDI) for Palo Verde Nuclear Generating Station (PVNGS)
Units 1, 2, and 3. Use of the proposed alternative will provide an acceptable level of quality and safety, as described in attached Relief Request No. 26.
By letter dated February 26, 2004, the NRC Staff authorized the use of a similar alternative for Duane Arnold Energy Center, Monticello Nuclear Generating Plant, Prairie Island Nuclear Generating Plants, Units I and 2, Kewaunee Nuclear Power Plant, Point Beach Nuclear Plant, Units 1 and 2, and Palisades Nuclear Plant (TAC Nos. MC0814, MC0816, MC0820, MC0821, MC0815, MC0818, MC0819 and MC0817)
APS requests review of this relief by July 05, 2004, to support the 2004 spring refueling outage for PVNGS Unit 1 scheduled to end on May 6, 2004. Approval by this date would allow APS to take credit for welds examined during the Unit 1 spring outage using the alternate qualification requirements identified in RR No. 26 to be reported in the Inservice Inspection Summary Report issued 90 days after the completion of the outage.
AD<7V
U. S. Nuclear Regulatory Commission Second Ten-Year Interval Inservice Inspection Program Relief Request No. 26 - Relief from ASME Code, Section Xl, Appendix VIII, Supplement 10 Inservice Inspection Summary Report issued 90 days after the completion of the outage.
No new commitments are being made to the NRC by this letter. If you have any questions concerning this matter, please contact Thomas N. Weber at (623) 393-5764.
Sincerely, A69)
GRO/SAB/RJR/kg
Enclosure:
Relief Request No. 26 - Relief from ASME Code, Section Xl, Appendix VIII, Supplement 10 cc:
B. S. Mallett (w/Enclosure)
M. B. Fields (w/Enclosure)
N. L. Salgado (w/Enclosure) 2
- Relief Request No. 26 I. ASME Code Component(s) Affected Pressure retaining piping welds subject to examination using procedures, personnel, and equipment qualified to ASME Section Xl, 1995 Edition, 1996 Addenda, Appendix VIII, Supplement 10 criteria.
II. Applicable Code Addition and Addenda Second 1 0-year inservice inspection interval code for Palo Verde Nuclear Generating Station (PVNGS) Units 1, 2, and 3: The American Society of Mechanical Engineers (ASME) Code, Section Xl, 1992 Edition, 1992 Addenda.
Construction code for PVNGS Units 1, 2, and 3: ASME Section 1II, 1971 Edition, 1973 Winter Addenda.
Installation code for PVNGS Units 1, 2, and 3: ASME Section 1II, 1974 Edition, 1975 Winter Addenda.
Ill.Applicable Requirements The following paragraphs or statements are from ASME Section XI, Rules for Inservice Inspection of Nuclear Power Plant Components, 1995 Edition, 1996 Addenda, Appendix VIII, Supplement 10, Qualification Requirements for Dissimilar Metal Piping Welds, 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%.
1
Relief Request 26 Item 6 -
Paragraph 2.0 first sentence states - The specimen inside surface and identification shall be concealed from the candidate.
Item 7-Paragraph 2.2(b) states in part - The regions containing a flaw to be sized shall be identified to the candidate.
Item 8 -
Paragraph 2.2(c) states in part - For a separate length sizing test, the regions of each specimen containing a flaw to be sized shall be identified to the candidate.
Item 9 -
Paragraph 2.3(a) states - For the depth sizing test, 80% of the flaws shall be sized at a specific location on the surface of the specimen identified to the candidate.
Item 10 - Paragraph 2.3(b) states - For the remaining flaws, the regions of each specimen containing a flaw to be sized shall be identified to the candidate.
The candidate shall determine the maximum depth of the flaw in each region.
Item 11-Table Vill-S2-1 provides the false call criteria when the number of unflawed grading units is at least twice the number of flawed grading units.
IV. Relief Requested Relief is requested to use alternative requirements for implementation of Appendix Vil, Supplement 10 requirements. The alternative requirements will be implemented through the PDI Program. A copy of the proposed revision to Supplement 10 is included in the attachment to this request. 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 Committee for consideration.
V. Basis for Relief Item 1-The proposed alternative to Paragraph 1.1 (b) states:
"The specimen set shall include the minimum and maximum pipe diameters and thicknesses for which the examination procedure is applicable. Pipe diameters within a range of one-half 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."
2
I
. 1, t.,
I,
Relief Request 26 Technical Basis The change in the minimum pipe diameter tolerance from 0.9 times the diameter to the nominal diameter minus 0.5 inch provides tolerances more in line with industry practice. Though the alternative is less stringent for small pipe diameters they typically have a thinner wall thickness than larger diameter piping. A thinner wall thickness results in shorter sound path distances that reduce the detrimental effects of the curvature. This change maintains consistency between Supplement 10 and the recent revision to Supplement 2.
Item 2 - The proposed alternative to Paragraph 1.1 (d) states:
At least 60% of the flaws shall be cracks, the remainder shall be alternative flaws.
Specimens with IGSCC shall be used when available. Alternative flaws, if used, shall provide crack-like reflective characteristics and shall be limited to the case where implantation of cracks produces spurious reflectors that are uncharacteristic of actual flaws. Alternative flaw mechanisms shall have a tip width of less than or equal to 0.002 in. (.05 mm).
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.
3
Relief Request 26 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. 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 V111-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 S10-1 provides a statistically based ratio between the number of unflawed grading units and the number of flawed grading units. The proposed alternative reduces the ratio to 1.5 times to reduce the number of test samples to a more reasonable number from the human factors perspective. However, the statistical basis used for screening personnel and procedures is still maintained at the same level with competent personnel being successful and less skilled personnel being unsuccessful. The acceptance criteria for the statistical basis are in Table Vil-S10-1.
Item 5 - The proposed alternative to the flaw distribution requirements of Paragraph 1.2(c)(1) (detection) and 1.3(c) (length) is to use the Paragraph 1.4(b)
(depth) distribution table (see below) for all qualifications.
Flaw Depth Minimum
(% Wall Thickness)
Number of Flaws 10-30%
20%
31-60%
20%
61-100%
20%
In addition, the proposed alternative includes the following: "At least 75% of the flaws shall be in the range of 10 to 60% of wall thickness."
4
Relief Request 26 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 alternative differentiates between ID and 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 Uregions" 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."
5
Relief Request 26 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-SZ-1 PERFORMANCE DEMONSTRATION DEECTION TEST ACCEPTANCE CRITERIA Detection Test False Call Test Acceptance Critera Acceptance Criteria No. of No. of Maximum Flawed Minimum Unflawed Number AGrading Detection Grading of False Units Critedia Units
.Calis 5
5 10
.6 6 -2
<7 6
-11 i
7.
V..
6 10 8
a-15 2
11 -
9 2-17 3
- 12.
9 24-18 13 10 26-20 4-3 14 10 2-21 3
15 11 30-23 16 12 32-24 4
17
-12:
23 6 64 I8 13 27
!4 19 13 3
.29 7-4 20 14 4-30 8-5 6
Relief Request 26 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, Pacific Northwest National Laboratory (PNNL) has reviewed the statistical significance of these revisions and offered the revised Table S10-1.
VI. Alternative Examination In lieu of the requirements of ASME Section Xl, 1995 Edition, 1996 Addenda, Appendix VilI, Supplement 10, the proposed alternative shall be used. The proposed alternative is described in the attachment to this enclosure.
VII. Justification for Granting Relief Pursuant to 10 CFR 50.55a(a)(3)(i), approval is requested to use the proposed alternatives described above in lieu of the ASME Section Xl, 1995 Edition, 1996 Addenda, Appendix VilI, Supplement 10 requirements. Compliance with the proposed alternatives will provide an adequate level of quality and safety for examination of the affected welds.
Vil. Implementation Schedule APS requests review of this relief by July 05, 2004, to support the 2004 spring refueling outage for PVNGS Unit 1 scheduled to end on May 6, 2004. Approval by this date would allow APS to take credit for welds examined during the Unit 1 spring outage using the alternate qualification requirements identified in RR No.
26 and reported in the Inservice Inspection Summary Report issued 90 days after the completion of the outage.
IX. Precedence Nine Mile Point Nuclear Stations I and 2 November 21, 2003 ML033240060 San Onofre Nuclear Generating Station Unit 3 August 27, 2003 ML032390449 Three Mile Island Nuclear Station Unit 1 September 5, 2003 ML032320548 7
Attachment to Relief Request No. 26 1
SUPPLEMENT 10 - QUALIFICATION REQUIREMENTS FOR DISSIMILAR METAL PIPING WELDS l
Current Requirement PDI Proposed Change Reasoning 1.0 SCOPE Supplement 10 is applicable to dissimilar A scope statement provides added metal piping welds examined from either clarity regarding the applicable range the inside or outside surface.
of each individual Supplement. The Supplement 10 is not applicable to exclusion of CRC provides piping welds containing supplemental consistency between Supplement 10 corrosion resistant clad (CRC) applied tc and the recent revision to Supplement mitigate Intergranular Stress Corrosion 2 (Reference BC 00-755). Note, an Cracking (IGSCC).
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 Qualification test specimens shall meet the No Change meet the requirements listed herein, requirements listed herein, unless a set of unless a set of specimens is designed specimens is designed to accommodate to accommodate specific limitations specific limitations stated in the scope of stated in the scope of the examination the examination procedure (e.g., pipe size, procedure (e.g., pipe size, weld joint weld joint configuration, access configuration, access limitations). The limitations). The same specimens may be same specimens may be used to used to demonstrate both detection and demonstrate both detection and sizing sizing qualification.
qualification.
1.1 General. The specimen set shall 2.1 General.
Renumbered conform to the following requirements.
The specimen set shall conform to the following requirements.
(a) The minimum number of flaws in a New, changed minimum number of specimen set shall be ten.
flaws to 10 so sample set size for detection is consistent with length and depth sizing.
(a) Specimens shall have sufficient (b) Specimens shall have sufficient Renumbered volume to minimize spurious volume to minimize spurious reflections reflections that may interfere with the that may interfere with the interpretation interpretation process.
process.
Page 1 of 13 Developed Alternative Requirements RR No.26 PDI
SUPPLEMENT 10 - QUALIFICATION REQUIREMENTS FOR DISSIMILAR METAL PIPING WELDS l
Current Requirement PDI Proposed Change Reasoning (b) The specimen set shall include the (c) The specimen set shall include the Renumbered, metricated, the change minimum and maximum pipe minimum and maximum pipe diameters in pipe diameter tolerance provides diameters and thicknesses for which and thicknesses for which the examination consistency between Supplement 10 the examination procedure is procedure is applicable. Pipe diameters and the recent revision to Supplement applicable. Pipe diameters within a within 112 in. (13 mm) of the nominal 2 (Reference BC 00-755) range of 0.9 to 1.5 times a nominal diameter shall be considered equivalent.
diameter shall be considered Pipe diameters larger than 24 in.
equivalent. Pipe diameters larger than (610 mm) shall be considered to be flat.
24 in. shall be considered to be flat.
When a range of thicknesses is to be When a range of thicknesses is to be examined, a thickness tolerance of +25%
examined, a thickness tolerance of is acceptable.
+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 require discrimination from flaws (e.g.,
normally require discrimination from flaws relate to material conditions rather counterbore or weld root conditions, (e.g., counterbore or weld root conditions, than geometric conditions. Weld cladding, weld buttering, remnants of cladding, weld buttering, remnants of repair areas were added as a result of previous welds, adjacent welds in previous welds, adjacent welds in close recent field experiences.
close proximity);
proximity, and weld repair areas);
(2) typical limited scanning surface (2) typical limited scanning surface Differentiates between ID and OD conditions (e.g., diametrical shrink, conditions shall be included as follows:
scanning surface limitations. Requires single-side access due to nozzle and (a) for outside surface examination, weld that ID and OD qualifications be safe end external tapers).
crowns, diametrical shrink, single-side conducted independently (Note, new access due to nozzle and safe end paragraph 2.0 (identical to old external tapers paragraph 1.0) provides for (b) for inside surface examination, alternatives when 'a set of specimens internal tapers, exposed weld roots, is designed to accommodate specific and cladding conditions for inside limitations stated in the scope of the surface examinations).
examination procedure.").
(e) Qualification requirements shall be satisfied separately for outside surface Page 2 of 13 Developed Alternative Requirements RR No.26 PDI
SUPPLEMENT 10- QUALIFICATION REQUIREMENTS FOR DISSIMILAR METAL PIPING WELDS Current Requirement PDI Proposed Change Reasoning and inside surface examinations.
(d) All flaws in the specimen set shall Deleted this requirement, because be cracks.
new 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.
Renumbered and re-titled. Flaw in austenitic material. At least 50% of At least 80% of the flaws shall be location percentages redistributed the cracks in austenitic material shall contained wholly in weld or buttering because field experience indicates be contained wholly in weld or material. At least one and no more than that flaws contained in weld or buttering material. At least 10% of the 10% of the flaws shall be in ferritic base buttering material are probable and:
cracks shall be in ferritic material. The material. At least one and no more than represent the more stringent ultrasonic remainder of the cracks may be in 10% of the flaws shall be in austenitic detection scenario.
either austenitic or ferritic material.
base material.
(2) At least 50% of the cracks in 2.3 Flaw Type.
Renumbered and re-titled. Alternative austenitic base material shall be either (a) At least 60% of the flaws shall be flaws are required for placing axial IGSCC or thermal fatigue cracks. At cracks, and the remainder shall be flaws in the HAZ of the weld and other least 50% of the cracks in ferritic alternative flaws. Specimens with areas where implantation of a crack material shall be mechanically or IGSCC shall be used when available.
produces metallurgical conditions that thermally induced fatigue cracks.
Alternative flaws shall meet the result in an unrealistic ultrasonic following requirements:
response. This is consistent with the (1) Alternative flaws, if used, shall recent revision to Supplement 2 provide crack-like reflective (Reference BC 00-755).
characteristics and shall only be used when implantation of cracks would The 40% limit on alternative flaws is produce spurious reflectors that are needed to support the requirement for uncharacteristic of service-induced up to 70% axial flaws. Metricated flaws.
(2) Alternative flaws shall have a tip width no more than 0.002-in. (.05 mm).
(3) At least 50% of the cracks shall be (b) At least 50% of the flaws shall be Renumbered. Due to inclusion of coincident with areas described in (c) coincident with areas described in 2.1(d)
"alternative flaws", use of "cracks" is above.
above.
no longer appropriate.
Page 3 of 13 Developed Alternative Requirements RR No.26 PDI
SUPPLEMENT 10- QUALIFICATION REQUIREMENTS FOR DISSIMILAR METAL PIPING WELDS Current Requirement PDI Proposed Change Reasoning 2.4 Flaw Depth.
All flaw depths shall be greater than 10%
Moved from old paragraph 1.3(c) and of the nominal pipe wall thickness. Flaw 1.4 and re-titled. Consistency depths shall exceed the nominal clad between detection and sizing thickness when placed in cladding. Flaws specimen set requirements (e.g., 20%
in the sample set shall be distributed as vs. 1/3 flaw depth increments, e.g.,
follows:
original 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 Renumbered and re-titled and moved specimen set shall include detection to paragraph 3.1(a). No other specimens that meet the following changes requirements.
(a) Specimens shall be divided into Renumbered to paragraph 3.1(a)(1).
grading units. Each grading unit shall No other changes.
include at 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.
Page 4 of 13 RR No.26 PDI Developed Alternative Requirements
SUPPLEMENT 10- QUALIFICATION REQUIREMENTS FOR DISSIMILAR METAL PIPING WELDS Current Requirement PDI Proposed Change Reasoning (b) Detection sets shall be selected Moved to new paragraph 3.1(a)(2).
from 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 following criteria for flaw depth, new paragraph 2.4, flaw orientation orientation, and type.
requirements moved to new paragraph 2.5, flaw type requirements moved to new paragraph 2.3, "Flaw Type".
(1) All flaw depths shall be greater Deleted, for consistency in sample than 10% of the nominal pipe wall sets the depth distribution is the same thickness. At least 1/3 of the flaws, for detection 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.
(2) At least 30% and no more than 2.5 Flaw Orientation.
Note, this distribution is applicable for 70% of the flaws, rounded to the next (a) For other than sizing specimens at detection and depth sizing. Paragraph higher whole number, shall be least 30% and no more than 70% of the 2.5(b)(1) requires that all length-sizing oriented axially. The remainder of the flaws, rounded to the next higher whole flaws be oriented circumferentially.
flaws shall be oriented number, shall be oriented axially. The circumferentially.
remainder of the flaws shall be oriented circumferentially.
1.3 Length Sizing Specimens. The Renumbered and re-titled and moved specimen set shall include length to new paragraph 3.2 Page 5 of 13 RR No.26 PDI Developed Alternative Requirements
SUPPLEMENT 10 - QUALIFICATION REQUIREMENTS FOR DISSIMILAR METAL PIPING WELDS Current Requirement PDI Proposed Change Reasoning sizing specimens that meet the following requirements.
(a) All length sizing flaws shall be Moved, included in new paragraph oriented circumferentially.
3.2(a)
(b) The minimum number of flaws Moved, included in new paragraph 2.1 shall be ten.
above (c) All flaw depths shall be greater Moved, included in new paragraph 2.4 than 10% of the nominal pipe wall above after revision for consistency thickness. At least 1/3 of the flaws, with detection distribution rounded to the next 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 specimen set shall include depth 2.1, 2.3, 2.4 sizing specimens that meet the following requirements.
(a) The minimum number of flaws Moved, included in new paragraph 2.1 shall be ten.
(b) Flaws in the sample set shall not Moved, potential conflict with old be wholly contained within cladding paragraph 1.2(c)(1); 'However, flaw and shall be distributed as follows:
depths shall exceed the nominal clad thickness when placed in cladding.".
Revised for clarity and included in new I paragraph 2.4 Page 6 of 13 RR No.26 PDI Developed Alternative Requirements
SUPPLEMENT 10 - QUALIFICATION REQUIREMENTS FOR DISSIMILAR METAL PIPING WELDS Current Requirement PDI Proposed Change Reasoning Flaw Depth Minimum Moved, included in paragraph 2.4 for
(% Wall Thickness) Number of Flaws consistent applicability to detection 10-30%
20%
and sizing samples.
31-60%
20%
61-100%
20%
The remaining flaws shall be in any of the above categories.
(b) Sizing Specimen sets shall meet the Added for clarity following requirements.
(1) Length-sizing flaws shall be oriented Moved from old paragraph 1.3(a) circumferentially.
(2) Depth sizing flaws shall be oriented Included for clarity. Previously as in 2.5(a).
addressed by omission (i.e., length, but not depth had a specific exclusionary statement) 2.0 CONDUCT OF 3.0 PERFORMANCE Renumbered PERFORMANCE DEMONSTRATION DEMONSTRATION The specimen inside surface and Personnel and procedure performance Differentiate between qualifications identification shall be concealed from demonstration tests shall be conducted conducted from the outside and inside the candidate. All examinations shall according to the following surface.
be completed prior to grading the requirements.
results and presenting the results to (a) For qualifications from the outside the candidate. Divulgence of particular surface, the specimen inside surface specimen results or candidate viewing and identification shall be concealed of unmasked specimens after the from the candidate. When qualifications performance demonstration is are performed from the inside surface, prohibited.
the flaw location and specimen identification shall be obscured to maintain a "blind test". All examinations shall be completed prior to grading the results and presenting the results to the candidate. Divulgence of particular Page 7 of 13 Developed Alternative Requirements RR No.26 PDI
SUPPLEMENT 10- QUALIFICATION REQUIREMENTS FOR DISSIMILAR METAL PIPING WELDS Current Requirement PDI Proposed Change Reasoning specimen results or candidate viewing of unmasked specimens after the performance demonstration is prohibited.
2.1 Detection Test. Flawed and 3.1 Detection Test.
Renumbered, moved text to unflawed grading units shall be paragraph 3.1(a)(3) randomly mixed I
(a) The specimen set shall include Renumbered, moved from old detection specimens that meet the paragraph 1.2.
following requirements.
(1) Specimens shall be divided into Renumbered, moved from old grading units.
paragraph 1.2(a). Metricated. No (a) Each grading unit shall include at least other changes.
3 in. (76 mm) of weld length.
(b)The end of each flaw shall be separated from an unflawed grading unit by at least 1 in. (25 mm) of unflawed material. A flaw may be less than 3 in. in length.
(c) The segment of weld length used in one grading unit shall not be used in another grading unit.
(d) Grading units need not be uniformly spaced around the pipe specimen.
(2) Personnel performance demonstration Moved from old paragraph 1.2(b).
detection test sets shall be selected from Table revised to reflect a change in Table Vil-SIO-1. The number of unflawed the minimum sample set to 10 and the grading units shall be at least 1-1/2 times application of equivalent statistical the number of flawed grading units.
false call parameters to the reduction in unflawed grading units.
Human factors due to large sample size.
(3) Flawed and unflawed grading units Moved from old paragraph 2.1 shall be randomly mixed.
Page 8 of 13 RR No.26 PDI Developed Alternative Requirements
SUPPLEMENT 10 - QUALIFICATION REQUIREMENTS FOR DISSIMILAR METAL PIPING WELDS Current Requirement PDI Proposed Change Reasoning (b) Examination equipment and personnel Moved from old paragraph 3.1.
are qualified for detection when personnel Modified to reflect the 100% detection demonstrations satisfy the acceptance acceptance criteria of procedures criteria of Table Vil SIO-1 for both versus personnel and equipment detection and false calls.
contained in new 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 (a) Each reported circumferential flaw Provides consistency between conducted separately or in conjunction in the detection test shall be length-Supplement 10 and the recent revision with the detection test.
sized.
to Supplement 2 (Reference BC 00-755).
(b) When the length sizing test is (b) When the length-sizing test is Change made to ensure security of conducted in conjunction with the conducted in conjunction with the samples, consistent with the recent detection test, and less than ten detection test, and less than ten revision to Supplement 2 (Reference circumferential flaws are detected, circumferential flaws are detected, BC 00-755).
additional specimens shall be additional specimens shall be provided to provided to the candidate such that at the candidate such that at least ten flaws Note, length and depth sizing use the least ten flaws are sized. The regions are sized. The regions containing a flaw to term uregions" while detection uses containing a flaw to be sized shall be be sized may be identified to the the term "grading units". The two identified to the candidate. The candidate. The candidate shall determine terms define different concepts and candidate shall determine the length the length of the flaw in each region.
are not intended to be equal or of the flaw in each region.
interchangeable.
(c) For a separate length sizing test, (c) For a separate length-sizing test, the Change made to ensure security of the regions of each specimen regions of each specimen containing a samples, consistent with the recent containing a flaw to be sized shall be flaw to be sized may be identified to the revision to Supplement 2 (Reference identified to the candidate. The candidate. The candidate shall determine BC 00-755).
candidate shall determine the length the length of the flaw in each region.
of the flaw in each region.
Page 9 of 13 RR No.26 PDI Developed Alternative Requirements
SUPPLEMENT 10 - QUALIFICATION REQUIREMENTS FOR DISSIMILAR METAL PIPING WELDS Current Requirement PDI Proposed Change Reasoning (d) Examination procedures, equipment, Moved from old paragraph 3.2(a) and personnel are qualified for length-includes inclusion of uwhen' as an sizing when the RMS error of the flaw editorial change.
length measurements, as compared to the Metricated.
true flaw lengths, do not exceed 0.75 in.
(19 mm).
2.3 Depth Sizing Test 3.3 Depth Sizing Test Renumbered (a) For the depth sizing test, 80% of (a) The depth-sizing test may be Change made to ensure security of the flaws shall be sized at a specific conducted separately or in conjunction samples, consistent with the recent location on the surface of the with the detection test. For a separate revision to Supplement 2 (Reference specimen identified to the candidate.
depth-sizing test, the regions of each BC 00-755).
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 (b) When the depth-sizing test is Change made to be consistent with regions of each specimen containing a conducted in conjunction with the the recent revision to Supplement 2 flaw to be sized shall be identified to detection test, and less than ten flaws (Reference BC 00-755).
the candidate. The candidate shall are detected, additional specimens determine the maximum depth of the shall be provided to the candidate such Changes made to ensure security of flaw in each region.
that at least ten flaws are sized. The samples, consistent with the recent regions of each specimen containing a revision to Supplement 2 (Reference flaw to be sized may be identified to the BC 00-755).
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 Metricated.
sizing when the RMS error of the flaw depth measurements, as compared to the true flaw depths, do not exceed 0.125 in.
(3 mm).
Page 10 of 13 Developed Alternative Requirements RR No.26 PDI
SUPPLEMENT 10- QUALIFICATION REQUIREMENTS FOR DISSIMILAR METAL PIPING WELDS Current Requirement PDI Proposed Change Reasoning 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),
Examination procedures, equipment, reference changed to Table S10 from and personnel are qualified for S2 because of the change in the detection when the results of the minimum number of flaws and the performance demonstration satisfy the reduction in unflawed grading units acceptance criteria of Table VlIl-S2-1 from 2X to 1.5X.
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, Moved to new paragraph 3.2(d),
equipment, and personnel are included word 'when" as an editorial qualified for length sizing the RMS change.
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, Moved to new paragraph 3.3(c) equipment, and personnel are qualified for depth sizing when the RMS error of the flaw depth measurements, as compared to the true flaw depths, is less than or equal to 0.125 in.
4.0 PROCEDURE QUALIFICATION New Procedure qualifications shall include New. Based on experience gained in the following additional requirements.
conducting qualifications, the (a) The specimen set shall include the equivalent of 3 personnel sets (i.e., a equivalent of at least three personnel minimum of 30 flaws) is required to performance demonstration test sets.
provide enough flaws to adequately
_ Successful personnel performance test the capabilities of the procedure.
Page 11 of 13 RR No.26 PDI Developed Alternative Requirements
SUPPLEMENT 10- QUALIFICATION REQUIREMENTS FOR DISSIMILAR METAL PIPING WELDS Current Requirement PDI Proposed Change Reasoning demonstrations may be combined to Combining successful satisfy these requirements.
demonstrations allows a variety of (b) Detectability of all flaws in the examiners to be used to qualify the procedure qualification test set that are procedure. Detectability of each within the scope of the procedure shall flaw within the scope of the be demonstrated. Length and depth procedure is required to ensure an sizing shall meet the requirements of acceptable personnel pass rate.
paragraph 3.1, 3.2, and 3.3.
The last sentence is equivalent to (c) At least one successful personnel the previous requirements and is demonstration shall be performed.
satisfactory for expanding the (d) To qualify new values of essential essential variables of a previously variables, at least one personnel qualified procedure qualification set is required. The acceptance criteria of 4.0(b) shall be met.
Page 12 of 13 RR No.26 PDI Developed Altemative Requirements
I SUPPLEMENT 10- QUALIFICATION REQUIREMENTS FOR DISSIMILAR METAL PIPING WELDS I
TABLE VIII-S2.1 PERFORMANCE DEMONSTRATIONDETECTION TEST ACCETANCE CRITERIA r
Detetbn Test False Call Test Acceptance Critera Accepitance Criteria No. of No. of Maximum Flawed Minimum Unfl - dNumber Grading Detection-Grading of False Units Critena U;its.Calls t
6 6
12 1
7 6
i4 0a 7
1C1 9a 7
2 Q -J io 11 12 13 14 15 16' 17 18 19 20 8
9 10 10 11 12 12 13 13 14 20- is 2-17 24-178 26-20 28--`21 30- 23 32-. 24 34-26 34-27
- 3.
29 40- 30 3_2 j_33 3-3.
4-3 5-83 5-3-.
6-.4 A-4 8-5 RR No.26 PDI Developed Alternative Page 13 of 13 Requirements