ML031950117
| ML031950117 | |
| Person / Time | |
|---|---|
| Site: | Oconee, Mcguire, Catawba, McGuire  |
| Issue date: | 07/01/2003 |
| From: | Mccollum W Duke Energy Corp |
| To: | Document Control Desk, Office of Nuclear Reactor Regulation |
| References | |
| Download: ML031950117 (23) | |
Text
Duke Duke Energy Corporation Duke
~~~~~~~~~~~~~~~~~~~~~526 South Church Street c _ Energy.
PO. Box 1006 Charlotte, NC 28201-1006 July 1, 2003 U. S. Nuclear Regulatory Commission Washington, D.C. 20555-0001 ATTENTION: Document Control Desk
SUBJECT:
Duke Energy Corporation Oconee Nuclear Station, Units 1, 2, & 3 Docket Nos. 50-269, 50-270, 50-287 McGuire Nuclear Station, Units 1 & 2 Docket Nos. 50-369, 50-370 Catawba Nuclear Station, Units 1 & 2 Docket Nos. 50-413, 50-414 Relief Request for Alternative to ASME Section XI Relief Request 03-GO-009 Pursuant to 10 CFR 50.55a (a) (3) (i), Duke Energy Corporation (Duke) requests the use of an alternative to the requirements of ASME Boiler and Pressure Vessel Code,Section XI, Appendix VIII 1995 Edition through 1996 Addenda, Supplement 10 for the remainder of the third inspection interval of Oconee Units 1, 2, and 3, and the remainder of the second inspection interval of McGuire Units I and 2 and Catawba Units 1 and 2.
Specifically, Duke proposes an alternative for the qualification of personnel, procedures and equipment used to ultrasonically examine of Category B-F and Category C-F Pressure Retaining Dissimilar Metal piping welds. This alternative is consistent with industry guidance from EPRI.
A detailed description of the proposed alternative and justification is included as an attachment to this letter.
This relief is being sought in order to implement the requirements of 10 CFR 50.55a(b)(2)(xv)(A)(2) and the guidance of RIS 03-001, NRC Regulatory Issue Summary 2003-01, Examination of Dissimilar Metal Welds, Supplement 10 to Appendix VIII of Section XI of the ASME Code. Duke is also talking action to qualify vendors to perform inspections in accordance with the Performance Demonstration Initiative (PDI). Duke intends to implement this program during the Catawba Unit 1 outage scheduled for November 8, 2003, if vendors qualify. In this case, Duke is requesting approval of this request by October 31, 2003, to support implementation during that outage. If vendors fail to qualify for the fall Catawba outage, then Duke will defer these examinations to the next outage. If this occurs, then approval of this relief request would be needed for the October 2004 Oconee Unit 3 outage.
o0%
U. S. Nuclear Regulatory Commission July 1, 2003 Page 2 Questions regarding this request may be directed to R. K. Nader at 704-382-0979.
Very truly yours, W. R. McCollu r.
Senior Vice Presiden uclear Support
U. S. Nuclear Regulatory Commission July 1, 2003 Page 3 Attachment xc wlatt:
L. A. Reyes, Regional Administrator U. S. Nuclear Regulatory Commission, Region II Atlanta Federal Center 61 Forsyth St., SW, Suite 23T85 Atlanta, GA 30303 L. N. Olshan (Addressee only)
NRC Senior Project Manager (ONS)
U. S. Nuclear Regulatory Commission Mail Stop 0-8 H12 Washington, DC 20555-0001 R. E. Martin (Addressee only)
NRC Senior Project Manager (MNS and CNS)
U. S. Nuclear Regulatory Commission Mail Stop 0-8 H12 Washington, DC 20555-0001 M. E. Shannon, Senior Resident Inspector (ONS)
E. F. Guthrie, NRC Senior Resident Inspector (CNS)
J. B. Brady, NRC Senior Resident Inspector (MNS)
03-GO-009 Page 1 of 8 Duke Energy Corporation McGuire Unit 1 & 2 Catawba Units 1 2
Oconee Units 1, 2 3
10-YEAR INERVAL REQUEST FOR RELIEF NO. 03-GO-009 Pursuant to 10 CFR 50.55a (a)(3)
(i), Duke Energy Corporation proposes an alternative to the requirements of ASME Section XI, IWA-2300, 1995 Edition through the 1996 Addenda.
I.
SYSTEM/COMPONENT (S)
FOR WHICH RELIEF IS REQUESTED:
Duke Energy Corporation proposes an alternative for the qualification of personnel, procedures and equipment used to ultrasonically examine Category B-F and Category C-F Pressure Retaining Dissimilar Metal Piping Welds.
II.
CODE REQUIREMENTS:
ASME Section XI, Appendix VIII, 1995 Edition with the 1996 Addenda, Supplement 10 requires specific procedure, personnel and equipment qualifications.
III. Code Requirement for Which the Alternative is Requesteds Duke Energy Corporation proposes alternatives to the following requirements of ASME Section XI, Appendix VIII, Supplement 10:
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.
03-GO-009 Page 2 of 8 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.
IV. Basis for Relief: 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 enclosed.
It identifies the proposed alternatives and allows them to be viewed in context.
It also
03-GO-009 Page 3 of 8 identifies additional clarifications and enhancements for information.
It has been submitted to the ASME Code for consideration and as of September 2002 had been approved by the NDE Subcommittee.
Item 1 -
The proposed alternative to Paragraph 1.1(b) states:
"The specimen set shall -include the minimum and maximum pipe diameters and thicknesses for which the examination procedure is applicable.
Pipe diameters within a range of 1/2 in.
(13 mm) of the nominal diameter shall be considered equivalent.
Pipe diameters larger than 24 in.
(610 mm) shall be considered to be flat. When a range of thicknesses is to be examined, a thickness tolerance of +25%
is acceptable.
Justification 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."
03-GO-009 Page 4 of 8 Justification 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.
Excavation Mechanical fatigue crack
/
lare in Base atrial Item 3
The proposed alternative to Paragraph 1.l(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.
Justification -
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:
03-GO-009 Page 5 of 8 "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."
Justification -
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 VIII-S10-1.
Item 5 -
The proposed alternative to the flaw distribution requirements of Paragraph 1.2(c)(1)
(detection) and 1.3(c)
(length) is to use the Paragraph 1.4(b)
(depth) distribution table (see below) for all qualifications.
Flaw Depth Minimum
(% Wall Thickness)
Number of Flaws 10-30%
20%
31-60%
20%
61-100%
20%
Justification -
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.
03-GO-009 Page 6 of 8 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".'
Justification -
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.,
Justification -
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) states:
Regions of each specimen containing a flaw to be sized may be identified to the candidate.'
03-GO-009 Page 7 of 8 Justification a 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 YlI-Spl PERFORMANCE DEMONSTRAT ON DETECTION TEST ACCEPTANCE CRITERIA Detection Test False Call Test Acceptance Critera Acceptance Criteria No. of No. of Maximum Flawed Minimum Unflawed Number Grading Detection Grading of False Units Criteria Units Calls 5
5 10 a
6-6
~~
~
~1 1
6 14 1
e-i e 2
g 20- 15 3
7 12 10 8
29-152 11 9
- 1 7 3
12 9
24-18 3-3 13 10 2fT-4-
14 10 2
20 5
3 15 11 30- 21 s
3 16 12 32-23 3
17 12 3
24 6-4 18 13 326 4
19 13 3&- 27 7-4 20 14 40-
03-GO-009 Page 8 of 8 Justification -
The proposed alternative is identified as new Table 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 Northwest National laboratory (PNNL) has reviewed the statistical significance of these revisions and offered the revised Table S10-1.
V.
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. Additionally, for dissimilar metal piping welds examined from the inside surface of pressurized water reactors, the alternative presented in Duke Energy Corporation Relief Request 03-GO-Oll will also be used.
VI.
JUSTIFICATION FOR GRANTING RELIEF:
Approval is requested to use the proposed alternatives described above in lieu of the ASME Section XI, 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.
VII.
IMPLEMENTATION SCHEDULE:
Duke Energy Corporation will perform ultrasonic examinations of Category B-F and Category C-F dissimilar metal piping welds for the remainder of the 3rd 10-year Inspection Interval for Oconee Units 1, 2 and 3 and the remainder of the 2nd 10-year Inspection Interval for McGuire Units 1 and 2 and Catawba Units 1 and 2.
Sponsored By:
C Date:
23 Approved By:
Date: 4
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 indi-the inside or outside surface. Supple-vidual Supplement. The exclusion of CRC ment 10 is not applicable to piping welds provides consistency between Supplement containing supplemental corrosion resis-10 and the recent revision to Supplement 2 tant clad (CRC) applied to mitigate (Reference BC 00-755). Note, an addi-Intergranular Stress Corrosion Cracking tional change identifying CRC as "in course (IGSCC).
of preparation" is being processed sepa-rately.
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 spe-specimens is designed to accommodate spe-cific limitations stated in the scope of the cific 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 demon-same specimens may be used to demon-strate both detection and sizing strate both detection and sizing qualification.
qualification._
1.1 General. The specimen set shall con-2.1 General. The specimen set shall con-Renumbered form to the following requirements.
form to the following requirements.
(a) The minimum number of flaws in a New, changed minimum number of flaws to test set shall be ten.
10 so sample set size for detection is consis-tent with length and depth sizing.
(a) Specimens shall have sufficient volume (b) Specimens shall have sufficient volume Renumbered to minimize spurious reflections that may to minimize spurious reflections that may interfere with the interpretation process.
interfere with the interpretation process.
(b) The specimen set shall include the (c) The specimen set shall include the Renumbered, metricated, the change in pipe minimum and maximum pipe diameters and minimum and maximum pipe diameters and diameter tolerance provides consistency Page 1 of 12 Enclosure
SUPPLEMENT 10 - QUALIFICATION REQUIREMENTS FOR DISSIMILAR METAL PIPING WELDS Current Requirement Proposed Change Reasoning thicknesses for which the examination pro-thicknesses for which the examination pro-between Supplement 10 and the recent revi-cedure is applicable. Pipe diameters within cedure is applicable. Pipe diameters within sion to Supplement 2 (Reference BC 00-a range of 0.9 to 1.5 times a nominal diame-a range of 1/2 in. (13 mm) of the nominal 755) ter shall be considered equivalent. Pipe diameter shall be considered equivalent.
diameters larger than 24 in. shall be consid-Pipe diameters larger than 24 in. (610 mm) ered to be flat. When a range of thicknesses shall be considered to be flat. When a range is to be examined, a thickness tolerance of of thicknesses is to be examined, a thick-
+25% is acceptable.
ness tolerance of +25% is acceptable.
(c) The specimen set shall include examples (d) The specimen set shall include exam-Renumbered, changed "condition" to "eon-of the following fabrication condition:
es of the following fabrication conditions:
ditions" (1) geometric conditions that normally re-(1) geometric and material conditions that Clarification, some of the items listed relate quire discrimination from flaws (e.g.,
normally require discrimination from flaws to material conditions rather than geometric counterbore or weld root conditions, clad-(e.g., counterbore or weld root conditions, conditions. Weld repair areas were added ding, weld buttering, remnants of previous cladding, weld buttering, remnants of pre-as a result of recent field experiences.
welds, adjacent welds in close proximity);
vious welds, adjacent welds in close.
proximity, and weld repair areas);
(2) typical limited scanning surface condi-(2) typical limited scanning surface condi-Differentiates between ID and OD scanning tions (e.g., diametrical shrink, single-side tions (e.g., weld crowns, diametrical surface limitations. Requires that ID and access due to nozzle and safe end external shrink, single-side access due to nozzle and OD qualifications be conducted independ-tapers).
safe end external tapers for outside surface ently (Note, new paragraph 2.0 (identical to examinations; and Internal tapers, ex-old paragraph 1.0) provides for alternatives, posed weld roots, and cladding when "a set of specimens is designed to ac-conditions for Inside surface examina-commodate specific limitations stated in the tions). Qualification requirements shall scope of the examination procedure.").
be satisfied separately for outside surface and inside surface examinations.
(d) All flaws in the specimen set shall be Deleted this requirement, because new cracks.
paragraph 2.3 below provides for the use of "alternative flaws" in lieu of cracks.
(1) At least 50% of the cracks shall be in 2.2 Flaw Location. At least 80% of the Renumbered and re-titled. Flaw location Page 2 of 12 Enclosure
-I SUPPLEMENT 10 - QUALIFICATION REQUIREMENTS FOR DISSIMILAR METAL PIPING WELDS Current Requirement Proposed Change Reasoning austenitic material. At least 50% of the flaws shall be contained wholly in weld or percentages redistributed because field ex-cracks in austenitic material shall be con-buttering material. At least one and a perience indicates that flaws contained in tained wholly in weld or buttering material.
maximum of 10% of the flaws shall be in weld or buttering material are probable and At least 10% of the cracks shall be in fer-ferritic base material. At least one and a represent the more stringent ultrasonic de-ritic material. The remainder of the cracks maximum of 10% of the flaws shall be In tection scenario.
may be in either austenitic or ferritic mate-austenitic base material.
rial.
(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 mechani-flaws. Specimens with IGSCC shall be implantation of a crack produces metallur-cally or thermally induced fatigue cracks.
used when available. Alternative flaws, If gical conditions that result in an unrealistic used, shall provide crack-like reflective ultrasonic response. This is consistent with characteristics and shall be limited to the the recent revision to Supplement 2 (Refer-case where implantation of cracks pro-ence BC 00-755).
duces spurious reflectors that are uncharacteristic of actual flaws. Alterna-The 40% limit on alternative flaws is tive flaw mechanisms shall have a tip needed to support the requirement for up to width of less than or equal to 0.002 in.
70% axial flaws. Metricated
(.05 mm).
(3) At least 50% of the cracks shall be coin-(b) At least 50% of the flaws shall be coin-Renumbered. Due to inclusion of "alterna-cident with areas described in (c) above.
cident with areas described in 2.1(d) above.
tive flaws", use of "cracks" is no 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 detec-thickness. Flaw depths shall exceed the tion and sizing specimen set requirements nominal clad thickness when placed in (e.g., 20% vs. 1/3 flaw depth increments, cladding. Flaws in the sample set shall be e.g., original paragraph 1.3(c))
distributed as follows:
Page 3 of 12 Enclosure
SUPPLEMENT 10 - QUALIFICATION REQUIREMENTS FOR DISSIMILAR METAL PIPING WELDS Current Requirement T
Proposed Change Reasoning Flaw Depth Minimum
(% Wall Thickness) Number of Flaws 10-30%
20%
31-60%
20%
61-100%
20%
At least 75% of the flaws shall be In the range of 10 to 60% of wall thickness.
1.2 Detection Specimens. The specimen set Renumbered and re-titled and moved to shall include detection specimens that meet paragraph 3.1(a). No other changes the following requirements.
(a) Specimens shall be divided into grading Renumbered to paragraph 3.1(a)(1). No units. Each grading unit shall include at other changes.
least 3 in. of weld length. If a grading unit is designed to be unflawed, at least 1 in. of unflawed material shall exist on either side of the grading unit. The segment of weld length used in one grading unit shall not be used in another grading unit. Grading units need not be uniformly spaced around the pipe specimen.
(b) Detection sets shall be selected from Moved to new paragraph 3.1(a)(2).
Table VIII-S2-1. The number of unflawed grading units shall be at least twice the number of flawed grading units.
(c) Flawed grading units shall meet the fol-Flaw depth requirements moved to new lowing criteria for flaw depth, orientation, paragraph 2.4, flaw orientation require-and type.
ments moved to new paragraph 2.5, flaw Page 4 of 12 Enclosure
%I SUPPLEMENT 10 - QUALIFICATION REQUIREMENTS FOR DISSIMILAR METAL PIPING WELDS Current Requirement Propoed Change Reasoning 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 thickness. At depth distribution is the same for detection least 1/3 of the flaws, rounded to the next and sizing.
higher whole number, shall have depths be-tween 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 nomi-nal pipe wall thickness.
(2) At least 30% and no more than 70% of 2.5 Flaw Orientation.
Note, this distribution is applicable for de-the flaws, rounded to the next higher whole (a) At least 30% and no more than 70% of tection and depth sizing. Paragraph number, shall be oriented axially. The re-the flaws, rounded to the next higher whole 2.5(b)(1) requires that all length-sizing mainder of the flaws shall be oriented number, shall be oriented axially. The re-flaws be oriented circumferentially.
circumferentially.
mainder of the flaws shall be oriented circumferentially.
1.3 Length Sizing Specimens. The speci-Renumbered and re-titled and moved to men set shall include length sizing new paragraph 3.2 specimens that meet the following require-ments.
(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 Page 5 of 12 Enclosure
SUPPLEMENT 10 - QUALIFICATION REQUIREMENTS FOR DISSIMILAR METAL PIPING WELDS Current Requirement Proposed Change Reasoning higher whole number, shall have depths be-tween 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 nomi-nal pipe wall thickness.
1.4 Depth Sizing Specimens. The speci-Moved, included in new paragraphs 2.1, men set shall include depth sizing 2.3,2.4 specimens that meet the following require-ments.
(a) The minimum number of flaws shall be Moved, included in new paragraph 2.1 ten.
(b) Flaws in the sample set shall not be Moved, potential conflict with old para-wholly contained within cladding and shall graph 1.2(c)(1); "However, flaw depths be distributed as follows:
shall exceed the nominal clad thickness when placed in cladding.". Revised for clarity and included in new paragraph 2.4 Page 6 of 12 Enclosure
SUPPLEMENT 10 - QUALIFICATION REQUIREMENTS FOR DISSIMILAR METAL PIPING WELDS Current Requirement Proposed Change Reasoning Moved, included in paragraph 2.4 for con-Flaw Depth Minimum sistent applicability to detection and sizing
(% Wall Thickness)
Number of Flaws 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 3.0 CONDUCT OF Renumbered PERFORMANCE DEMONSTRATION PERFORMANCE DEMONSTRATION The specimen inside surface and identifica-For qualifications from the outside sur-Differentiate between qualifications con-tion shall be concealed from the candidate.
face, the specimen inside surface and ducted from the outside and inside surface.
All examinations shall be completed prior identification shall be concealed from the to grading the results and presenting the re-candidate. When qualifications are per-sults to the candidate. Divulgence of formed from the inside surface, the flaw particular specimen results or candidate location and specimen identification shall viewing of unmasked specimens after the be obscured to maintain a "'blind test".
performance demonstration is prohibited.
All examinations shall be completed prior to grading the results and presenting the re-sults to the candidate. Divulgence of particular specimen results or candidate I viewing of unmasked specimens after the Page 7 of 12 Enclosure
SUPPLEMENT 10 - QUALIFICATION REQUIREMENTS FOR DISSIMILAR METAL PIPING WELDS Current Requirement l
Proposed Change Reasoning 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 specimens that meet the following require-1.2.
ments.
(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 uni-formly 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 to units.
the reduction in unflawed grading units.
Human factors due to large sample size.
(3) flawed and unflawed grading units shall Moved from old paragraph 2.1 be randomly mixed.
Page 8 of 12 Enclosure
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 are qualified for detection when personnel to reflect the 100% detection acceptance demonstrations satisfy the acceptance cri-criteria of procedures versus personnel and teria of Table VIII S10-1 for both detection equipment contained in new paragraph 4.0 and false calls.
and the use of 1.5X rather than 2X un-flawed grading units contained in new paragraph 3.1(a)(2). Note, the-modified table maintains the screening criteria of the original Table VIII-S2-1.
2.2 Length Sizing Test 3.2 Length Sizing Test Renumbered (a) The length sizing test may be conducted (a) Each reported circumferential flaw in Provides consistency between Supplement separately or in conjunction with the detec-the detection test shall be length sized.
10 and the recent revision to Supplement 2 tion test.
(Reference BC 00-755).
Page 9 of 12 Enclosure
SUPPLEMENT 10 - QUALIFICATION REQUIREMENTS FOR DISSIMILAR METAL PIPING WELDS Current Requirement Propsed Change Reasoning (b) When the length sizing test is conducted Change made to ensure security of samples, (b) When the length sizing test is conducted in conjunction with the detection test, and consistent with the recent revision to Sup-in conjunction with the detection test, and less than ten circumferential flaws are de-plement 2 (Reference BC 00-755).
less than ten circumferential flaws are de-tected, additional specimens shall be
- tected, 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 dif-a flaw to be sized shall be identified to the candidate. The candidate shall determine ferent concepts and are not intended to be candidate. The candidate shall determine the length of the flaw in each region.
equal or interchangeable.
the length of the flaw in each region.
(c) For a separate length sizing test, the re-Change made to ensure security of samples, (c) For a separate length sizing test, the re-gions of each specimen containing a flaw to consistent with the recent revision to Sup-gions of each specimen containing a flaw to be sized may be identified to the candidate.
plement 2 (Reference BC 00-755).
be sized shall be identified to the candidate.
The candidate shall determine the length of The candidate shall determine the length of the flaw in each region.
the flaw in each region.
(d) Examination procedures, equipment, 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 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 con-Change made to ensure security of samples, flaws shall be sized at a specific location on ducted separately or in conjunction with consistent with the recent revision to Sup-the surface of the specimen identified to the the detection test. For a separate depth plement 2 (Reference BC 00-755).
candidate.
sizing test, the regions of each specimen containing a flaw to be sized may be I identified to the candidate. The candidate Page 10 of 12 Enclosure
SUPPLEMENT 10 - QUALIFICATION REQUIREMENTS FOR DISSIMILAR METAL PIPING WELDS Current Requirement Proposed Change Reasoning 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 con-Change made to be consistent with the re-each specimen containing a flaw to be sized ducted in conjunction with the detection cent revision to Supplement 2 (Reference shall be identified to the candidate. The test, and less than ten flaws are detected, BC 00-755).
candidate shall determine the maximum additional specimens shall be provided to depth of the flaw in each region.
the candidate such that at least ten flaws Changes made to ensure security of sam-are sized. The regions of each specimen ples, consistent with the recent revision to containing a flaw to be sized may be identi-Supplement 2 (Reference BC 00-7-55).
fied 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). Metri-and personnel are qualified for depth sizing cated.
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. Exami-Moved to new paragraph 3.1(b), reference nation 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 demonstra-and the reduction in unflawed grading units tion satisfy the acceptance criteria of Table from 2X to 1.5X.
V1II-S2-1 for both detection and false calls.
3.2 Sizing Acceptance Criteria Deleted as a separate category. Moved to new paragraph on length 3.2 and depth 3.3 (a) Examination procedures, equipment, Moved to new paragraph 3.2(d), included Page 11 of 12 Enclosure
SUPPLEMENT 10 - QUALIFICATION REQUIREMENTS FOR DISSIMILAR METAL PIPING WELDS Current Requirement Proposed Change Reasoning and personnel are qualified for length sizing word "when" as an editorial change.
the RMS error of the flaw length measure-ments, as compared to the true flaw lengths, is less than or equal to 0.75 inch.
(b) Examination procedures, equipment, Moved to new paragraph 3.3(c) and personnel are qualified for depth sizing when the RMS error of the flaw depth measurements, as compared to the true flaw depths, is less than or equal to 0.125 in.
4.0 PROCEDURE QUALIFICATION New Procedure qualifications shall include the New. Based on experience gained in con-following additional requirements.
ducting qualifications, the equivalent of 3 (a) The specimen set shall include the personnel sets (i.e., a minimum of 30 flaws) equivalent of at least three personnel sets.
is required to provide enough flaws to ade-Successful personnel demonstrations may quately test the capabilities of the be combined to satisfy these require-procedure. Combining successful demon-ments.
strations allows a variety of examiners to be (b) Detectability of all flaws within the used to qualify the procedure. Detectability scope of the procedure shall be demon-of each flaw within the scope of the proce-strated. Length and depth sizing shall dure is required to ensure acceptable meet the requirements of paragraph 3.2 personnel pass rate. The last sentence is and 3.3.
equivalent to the previous requirements and (c) At least one successful personnel is satisfactory for expanding the essential demonstration has been performed.
variables of a previously qualified proce-(d) To qualify new values of essential dure variables, at least one personnel qualifica-I tion set is required.
II TABLE VII-S#-
PERFORMANCE DEMONSTRATION DETECTION TEST ACCEPTANCE CRITERIA Page 12 of 12 Enclosure