ML032310438
| ML032310438 | |
| Person / Time | |
|---|---|
| Site: | Nine Mile Point  |
| Issue date: | 08/08/2003 |
| From: | Katz P Constellation Energy Group |
| To: | Document Control Desk, Office of Nuclear Reactor Regulation |
| References | |
| NMPIL 1711 | |
| Download: ML032310438 (29) | |
Text
P.O. Box 63 Lycorning, New York 13093 Consellaton Energy Group Nine Mile Point Nuclear Station August 8, 2003 NMP1L 1711 U.S. Nuclear Regulatory Commission Attn.: Document Control Desk Washington, DC 20555-0001
SUBJECT:
Nine Mile Point Units 1 and 2 Docket Nos. 50-220 and 50410 License Nos. DPR-63 and NPF-69 Request for Relief from Qualification Requirements for Dissimilar Metal Piping Welds Gentlemen:
Nine Mile Point Nuclear Station, LLC (NMPNS) is submitting inservice inspection relief requests ISI-24A and ISI-24B for Nine Mile Point Unit 1 (NMP 1) and Unit 2 (NMP2),
respectively. Upon NRC approval, these relief requests will allow utilization of the performance demonstration initiative (PDI) program as an alternative to the American Society of Mechanical Engineers Boiler and Pressure Vessel Code (ASME Code), 1995 Edition with 1996 Addenda, Section X1, Appendix VIII, Supplement 10 requirements for dissimilar metal piping weld examinations. Relief is being requested in accordance with 10CFR50.55a(a)(3)(i) on the basis that the proposed alternative will provide an acceptable level of quality and safety. By letter dated June 23, 2003, the NRC approved similar relief requests for Florida Power and Light Company's St. Lucie Nuclear Plant, Units 1 and 2.
Relief requests ISI-24A and ISI-24B (included as Attachments 1 and 2) are based on Revision 1 of the Generic Requests for Relief for Supplement 10, as developed by PDI. The Enclosure cited in each relief request (included as Attachment 3) was prepared by PDI to compare the Supplement 10 requirements with the PDI proposed alternative requirements. Changes between the Supplement 10 requirements and the PDI proposed alternative requirements are highlighted by bold or "lined-through" text in the PDI proposed requirements.
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Page 2 NMP1L 1711 NMPNS requests NRC approval of relief requests ISI-24A and ISI-24B by February 15, 2004, to support weld examinations planned for NMP2 during the Spring 2004 refueling outage (RFO9).
Very truly yours, Peter E. Katz /
Vice President Nine MI Point BSMJlAA/jm Attachments cc: Mr. H. J. Miller, NRC Regional Administrator, Region I Mr. G. K. Hunegs, NRC Senior Resident Inspector Mr. P. S. Tam, Senior Project Manager, NRR (2 copies)
ATTACHMENT 1 (Relief Request ISI-24A for Nine Mile Point Unit 1)
NINE MILE POINT UNIT 1 THIRD INSERVICE INSPECTION INTERVAL RELIEF REQUEST ISI-24A A. COMPONENT IDENTIFICATION System: Various Systems Class: Quality Group A, ASME Code Class 1 Component
Description:
Pressure Retaining Piping Welds subject to examination using procedures, personnel, and equipment qualified to ASME Section XI, Appendix Vil, Supplement 10 criteria Component Identification: Attachment 1 provides a list of applicable dissimilar metal welds B. ASME CODE SECTION Xl REQUIREMENTS ASME Section XI, 1995 Edition with 1996 Addenda, Appendix Vill, Supplement 10, "Qualification Requirements For Dissimilar Metal Piping Welds."
The following paragraphs or statements are from ASME Section Xl, Appendix Vill, 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 aflaw 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.
R3 IS124A-1 OF ISI24A-8
NINE MILE POINT UNIT 1 THIRD INSERVICE INSPECTION INTERVAL RELIEF REQUEST ISI-24A Item 11 - Table VilI-S2-1 provides the false call criteria when the number of unflawed grading units is at least twice the number of flawed grading units.
Item 12 - Paragraph 3.2(b) states - Examination procedures, 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.
C. RELIEF REQUESTED Pursuant to 10 CFR 50.55a(a)(3)(i), Nine Mile Point Nuclear Station, LLC (NMPNS) requests relief to use the proposed alternative Performance Demonstration Initiative (PDI) Program described below in lieu of the ASME Code Section Xl, Appendix Vil, Supplement 10 requirements on the basis that the proposed alternative will provide an acceptable level of quality and safety for examination of the affected welds.
A copy of the proposed revision to Supplement 10 is attached as an Enclosure. 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.
In addition, NMPNS requests relief from the depth sizing less than or equal to 0.125 inch RMS error.
D. 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 % 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) 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 R3 ISI24A-2 OF ISI24A-8
NINE MILEPOINT UNIT 1 THIRD INSERVICE INSPECTION INTERVAL RELIEF REQUEST ISI-24A base material, must now travel through weld material on at least one side, producing an unrealistic flaw response. Inaddition, 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.
icn M hanical fatigue crack I areaI ~~~In Base material Item 3 - The proposed alternative to Paragraph 1.1 (d)(1) states:
"At least 80% of the flaws shall be contained wholly in weld or buttering material. At least one and a maximum of 10% of the flaws shall be in ferritic base material. At least one and a maximum of 10%
of the flaws shall be In austenitic base material."
Technical Basis - Under the current Code, as few as 25% of the flaws are contained in austenitic weld or buttering material. 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 Vill-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-Sl 0-1 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%
R3 IS124A-3 OF IS124A-8
NINE MILE POINT UNIT 1 THIRD INSERVICE INSPECTION INTERVAL RELIEF REQUEST ISI-24A 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 "regions" while detection uses the term "grading unitse - the two terms define different concepts and are not intended to be equal or interchangeable). To ensure security of the samples, the proposed alternative modifies the first "shall" to a "may" to allow the test administrator the option of not identifying specifically where a flaw is located.
This is consistent with the recent revision to Supplement 2.
Items 9 and 10 - The proposed alternative to Paragraph 2.3(a) and 2.3(b) state:
"... regions of each specimen containing a flaw to be sized may be identified to the candidate."
Technical Basis - The current Code requires that a large number of flaws be sized at a specific location.
The proposed alternative changes the "shall to a "may" which modifies this from a specific area to a more generalized region to ensure security of samples. This is consistent with the recent revision to Supplement 2. It also incorporates terminology from length sizing for additional clarity.
R3 ISI24A-4 OF ISI24A-8
NINE MILE POINT UNIT 1 THIRD INSERVICE INSPECTION INTERVAL RELIEF REQUEST ISI-24A Item 11 - The proposed alternative modifies the acceptance criteria of Table VlIlI-S2-1 as follows:
10 TABLE VIII-S2-1 PERFORMANCE DEMONSTRATION DETECTION TEST ACCEPTANCE CRITERIA Detection Test Acceptance Criteria False Call Test Acceptance Criteria No. of Flawed Minimum Detection No. of Unflawed Maximum Number of False Grading Units Criteria Grading Units Calls b b id -t 7 14 6 F~~ iC 2 7 InR 10 8 26 15 e 2 11 9 22- 17 93 12 9 e4 18 8 3 13 10 26 20 4 3 14 10 26- 21 5- 3 15 11 66 23 16 12. -82 24 6- 4 17 12 34 26 6 4 18 13 96 27 19 13 86 29 20 14 48 30 a 5 Technical Basis - The proposed alternative is identified as new Table VlIl-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 has reviewed the statistical significance of these revisions and offered the revised Table VIII-Sl 0-1.
Item 12 - The proposed alternative to Paragraph 3.2(b) states:
'Examination procedures, 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."
Technical Basis - The industry is in the process of qualifying personnel to Supplement 10; however, as of March 14, 2003, Nine Mile Point Nuclear Station was informed that personnel qualifying to the Supplement 10 procedures have not been successful in achieving the 0.125 inch RMS criteria for depth sizing. Industry personnel have only been capable of achieving an accuracy of 0.155 in. RMS.
R3 ISI24A-5 OF ISI24A-8
NINE MILE POINT UNIT 1 THIRD INSERVICE INSPECTION INTERVAL RELIEF REQUEST ISI-24A E. ALTERNATIVE EXAMINATIONS As an alternate to the requirements of ASME Section Xi, 1995 Edition, 1996 Addenda, Appendix Vil, Supplement 10, NMPNS proposes to use the PDI Program alternative as described in the Enclosure.
NMPNS also proposes that if a flaw is detected during the performance of an ultrasonic examination, the flaw will be sized using the depth sizing of a 0.155 inch RMS value determined during the PDI performance demonstration. In addition NMPNS proposes to take into account the increase in allowable depth sizing error, by adding the difference between the ASME Code required 0.125 inch RMS error and the demonstrated 0.155 inch RMS error to measurements acquired from actual flaw sizing. Specifically, 0.030 inches will be added to the measured flaw size when performing fracture mechanics calculations.
F. IMPLEMENTATION SCHEDULE The remainder of the Third Ten-Year Inservice Inspection Interval for Unit 1 (December 26, 1999 through December 25, 2009)
G. ATTACHMENTS Attachment 1 List of Applicable Dissimilar Metal Welds Enclosure Comparison of the ASME Code, Section Xl, Supplement 10 current requirements to the proposed changes.
R3 lSI24A-6 OF IS124A-8
NINE MILE POINT UNIT 1 THIRD INSERVICE INSPECTION INTERVAL RELIEF REQUEST ISI-24A Attachment 1 List of Applicable Dissimilar Metal Welds System Weld Weld Description System Weld Weld Description Identification Identification 00.0 RV-WD-01 Nozzle N7A to Flange 32.0 Reactor 32-WD-208 Nozzle N2E to Safe End Closure Head Recirculation 00.0 RV-WD-013 Nozzle N7B to Flange 32.0 Reactor 32-WD-002 Nozzle N1A to Safe End Closure Head Recirculation 00.0 RV-WD-015 Nozzle N7C to Flange 32.0 Reactor 32-WD-045 Nozzle N1B to Safe End Closure Head Recirculation 00.0 RV-WD-017 Nozzle N7D to Flange 32.0 Reactor 32-WD-085 Nozzle N1C to Safe End Closure Head Recirculation 00.0 RV-WD-019 Nozzle N7E to Flange 32.0 Reactor 32-WD-125 Nozzle N1 D to Safe End Closure Head Recirculation 00.0 RV-WD-021 Nozzle N7F to Flange 32.0 Reactor 32-WD-167 Nozzle N1 E to Safe End Closure Head Recirculation 00.0 RV-WD-023 Nozzle N7G to Flange 33.0 Reactor Water 33-WD-004 Pipe to Pipe Bend Closure Head Clean-Up 00.0 RV-WD-025 Nozzle N7H to Flange 33.0 Reactor Water 33-WD-014 Pipe to Pipe Closure Head Clean-Up 00.0 RV-WD-027 Nozzle N7J to Flange 36.0 Reactor 36-WD-003 Nozzle NI3A to Safe End Closure Head Instrumentation 00.0 RV-WD-029 Nozzle N7K to Flange 36.0 Reactor 36-WD-073 Nozzle N13B to Safe End Closure Head Instrumentation 00.0 RV-WD-031 Nozzle N7M to Flange 36.0 Reactor 36-WD-141 Nozzle N14A to Safe End Closure Head Instrumentation 00.0 RV-WD-033 Nozzle N7N to Flange 36.0 Reactor 36-WD-315 Nozzle N14B to Safe End Closure Head Instrumentation 00.0 RV-WD-035 Nozzle N7P to Flange 36.0 Reactor 36-WD-538 Nozzle N15A to Safe End Closure Head Instrumentation 00.0 RV-WD-037 Nozzle N7R to Flange 36.0 Reactor 36-WD-705 Nozzle N15B to Safe End Closure Head Instrumentation 00.0 RV-WD-039 Nozzle N7S to Flange 36.0 Reactor 36-WD-1000 Nozzle N16B to Safe End Closure Head Instrumentation 00.0 RV-WD-041 Nozzle N7T to Flange 36.0 Reactor 36-WD-924 Nozzle NI6A to Safe End Closure Head Instrumentation 00.0 RV-WD-043 Nozzle N7U to Flange 36.0 Reactor 36-WD-1074 Closure Head Nozzle N7i Closure Head Instrumentation to Flange 32.0 Reactor 32-WD-042 Nozzle N2A to Safe End 36.0 Reactor 36-WD-1 136 Nozzle N17B to Safe End Recirculation Instrumentation 32.0 Reactor 32-WD-082 Nozzle N2B to Safe End 37.0 Reactor Head 37-WD-002 Nozzle N8 to Flange Recirculation Vent 32.0 Reactor 32-WD-122 Nozzle N2C to Safe End 39.0 Emergency 39-WD-002 Nozzle N5A to Safe End Recirculation Condenser R3 IS124A-7 OF IS124A-8
NINE MILE POINT UNIT 1 THIRD INSERVICE INSPECTION INTERVAL RELIEF REQUEST ISI-24A Attachment 1 List of Applicable Dissimilar Metal Welds System Weld Weld Description System Weld Weld Description Identification Identification 32.0 Reactor 32-WD-164 Nozzle N2D to Safe End 39.0 Emergency 39-WD-090 Nozzle N5B to Safe End Recirculation Condenser 40.0 Reactor 40-WD-039 Nozzle N6A to Safe End 42.1 Liquid Poison 42.1-WD-034 Nozzle N12 to Safe End Core Spray 40.0 Reactor 40-WD-080 Nozzle N6B to Safe End 44.1 Control Rod 44.1-WD-017 Nozzle N9 to Safe End Core Spray Drive L ___________________ _______________________________________________
F= ,.__________________ _-________________
[ _______________________________________________
R3 IS124A-8 OF IS124A-8
ATTACHMENT 2 (Relief Request ISI-24B for Nine Mile Point Unit 2 )
NINE MILE POINT UNIT 2 SECOND INSERVICE INSPECTION INTERVAL RELIEF REQUEST ISI-24B A. COMPONENT IDENTIFICATION System: Various Systems Class: ASME Code Class 1 Component
Description:
Pressure Retaining Piping Welds subject to examination using procedures, personnel, and equipment qualified to ASME Section Xl, Appendix VIII, Supplement 10 criteria Component Identification: Attachment 1 provides a list of applicable dissimilar metal welds B. ASME CODE SECTION Xl REQUIREMENTS ASME Section XI, 1995 Edition with 1996 Addenda, Appendix Vil, Supplement 10, 'Qualification Requirements For Dissimilar Metal Piping Welds."
The following paragraphs or statements are from ASME Section Xl, Appendix Vil, 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.
ISI24B-1 OF ISI24B-7
NINE MILE POINT UNIT 2 SECOND INSERVICE INSPECTION INTERVAL RELIEF REQUEST ISI-24B Item 11 - Table Vlll-S2-1 provides the false call criteria when the number of unflawed grading units is at least twice the number of flawed grading units.
Item 12 - Paragraph 3.2(b) states - Examination procedures, 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.
C. RELIEF REQUESTED Pursuant to 10 CFR 50.55a(a)(3)(i), Nine Mile Point Nuclear Station, LLC (NMPNS) requests relief to use the proposed alternative Performance Demonstration Initiative (PDI) Program described below in lieu of the ASME Code, Section Xl, Appendix Vil, Supplement 10 requirements on the basis that the proposed alternative will provide an acceptable level of quality and safety for examination of the affected welds.
A copy of the proposed revision to Supplement 10 isattached as an Enclosure. 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.
In addition, NMPNS requests relief from the depth sizing less than or equal to 0.125 inch RMS error.
D. 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 'A2In. (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 isto 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)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 A3 IS124B-2 OF IS124B-7
NINE MILE POINT UNIT 2 SECOND INSERVICE INSPECTION INTERVAL RELIEF REQUEST ISI-24B response. Inaddition, 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.
l ~adn Mechanical fatigue crack (areal ~~~~in Base material Item 3 - The proposed alternative to Paragraph 1.1 (d)(1) states:
"At least 80% of the flaws shall be contained wholly in weld or buttering material. At least one and a maximum of 10% of the flaws shall be in ferritic base material. At least one and a maximum of 10%
of the flaws shall be in austenitic base material."
Technical Basis - Under the current Code, as few as 25% of the flaws are contained in austenitic weld or buttering material. 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 Vill-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-Sl 0-1 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 Vill-Sl 0-1.
Item 5 - The proposed alternative to the flaw distribution requirements of Paragraph 1.2(c)(1) (detection) and 1.3(c) (length) is to use the Paragraph 1.4(b) (depth) distribution table (see below) for all qualifications.
Flaw Depth Minimum
(% Wall Thickness) Number of Flaws 10-30% 20%
31-60% 20%
61-100% 20%
R3 ISI24B-3 OF ISI24B-7
NINE MILE POINT UNIT 2 SECOND INSERVICE INSPECTION INTERVAL RELIEF REQUEST ISI-24B 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 "regions" while detection uses the term "grading units" - the two terms define different concepts and are not intended to be equal or interchangeable). To ensure security of the samples, the proposed alternative modifies the first "shall" to a "may" to allow the test administrator the option of not identifying specifically where a flaw is located.
This is consistent with the recent revision to Supplement 2.
Items 9 and 10 - The proposed alternative to Paragraph 2.3(a) and 2.3(b) state:
"... regions of each specimen containing a flaw to be sized may be identified to the candidate."
Technical Basis - The current Code requires that a large number of flaws be sized at a specific location.
The proposed alternative changes the "shall" to a "may" which modifies this from a specific area to a more generalized region to ensure security of samples. This is consistent with the recent revision to Supplement 2. It also incorporates terminology from length sizing for additional clarity.
R3 ISI24B-4 OF ISI24B-7
NINE MILE POINT UNIT 2 SECOND INSERVICE INSPECTION INTERVAL RELIEF REQUEST ISI-24B Item 11 - The proposed alternative modifies the acceptance criteria of Table Vill-S2-1 as follows:
10 TABLE Vil-S2-11 PERFORMANCE DEMONSTRATION DETECTION TEST ACCEPTANCE CRITERIA Detection Test Acceptance Criteria False Call Test Acceptance Criteria No. of Flawed Minimum Detection No. of Unflawed Maximum Number of False Grading Units Criteria Grading Units Calls C C 412 1 7 C 14 1 I7 1- -
10 8 e2 15 62 11 9 22- 17 83 12 9 e4 18 8 3 13 10 26 20 4 3 14 10 26- 21 6-3 15 11 68 23 6 3 16 12 Be 24 6-4 17 12 84 26 6 4 18 13 86 27 19 13 Be 29 20 14 48 30 6 5 Technical Basis - The proposed alternative is identified as new Table Vill-Sl 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 has reviewed the statistical significance of these revisions and offered the revised Table Vill-S10-1.
Item 12 - The proposed alternative to Paragraph 3.2(b) states:
'Examination procedures, 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."
Technical Basis - The industry is in the process of qualifying personnel to Supplement 10; however, as of March 14, 2003, Nine Mile Point Nuclear Station was informed that personnel qualifying to the Supplement 10 procedures have not been successful in achieving the 0.125 inch RMS criteria for depth sizing. Industry personnel have only been capable of achieving an accuracy of 0.155 in. RMS.
R3 IS124B-5 OF IS124B-7
NINE MILE POINT UNIT 2 SECOND INSERVICE INSPECTION INTERVAL RELIEF REQUEST ISI-24B E. ALTERNATIVE EXAMINATIONS As an alternate to the requirements of ASME Section Xl, 1995 Edition, 1996 Addenda, Appendix Vill, Supplement 10, NMPNS proposes to use the PDI Program alternative as described in the Enclosure.
NMPNS also proposes that if a flaw is detected during the performance of an ultrasonic examination, the flaw will be sized using the depth sizing of a 0.155 inch RMS value determined during the PDI performance demonstration. In addition NMPNS proposes to take into account the increase in allowable depth sizing error, by adding the difference between the ASME Code required 0.125 inch RMS error and the demonstrated 0.155 inch RMS error to measurements acquired from actual flaw sizing. Specifically, 0.030 inches will be added to the measured flaw size when performing fracture mechanics calculations.
F. IMPLEMENTATION SCHEDULE The remainder of the Second Ten-Year Inservice Inspection Interval for Unit 2 (April 5, 1998 through April 4, 2008)
G. ATTACHMENTS Attachment 1 List of Applicable Dissimilar Metal Welds Enclosure Comparison of the ASME Code, Section Xl, Supplement 10 current requirements to the proposed changes.
R3 ISI24B-6 OF ISI24B-7
NINE MILE POINT UNIT 2 SECOND INSERVICE INSPECTION INTERVAL RELIEF REQUEST ISI-24B Attachment 1 List of Applicable Dissimilar Metal Welds System Weld Identification Weld Description ISC - Reactor Vessel Instrument 21SC-102CDA-FW001 NOZ SOC WELD @ N14B ISC - Reactor Vessel Instrument 21SC-102CDA-FW005 NOZ SOC WELD @ N14C ISC - Reactor Vessel Instrument 21SC-1 04CDA-FWOO1 NOZ SOC WELD @ N13B ISC - Reactor Vessel Instrument 21SC-105CDA-FW001 NOZ SOC WELD @ N14A ISC - Reactor Vessel Instrument 21SC-105CDA-FW007 NOZ SOC WELD @ N14D ISC - Reactor Vessel Instrument 21SC-107CDA-FW001 NOZ SOC WELD @ N13A ISC - Reactor Vessel Instrument 21SC-208CDA-FW001 NOZ SOC WELD @ N12B ISC - Reactor Vessel Instrument 21SC-210CDA-FW001 NOZ SOC WELD @ N12C ISC - Reactor Vessel Instrument 21SC-215CDA-FW001 NOZ SOC WELD @ N12D ISC - Reactor Vessel Instrument 21SC-217CDA-FW001 NOZ SOC WELD @ N12A RCS - Reactor Recirculation 2RPV-KBOi NOZ/SE @ N1A Az 000 RECIRC OUTLET RCS - Reactor Recirculation 2RPV-KBO2 NOZ/SE @ N1 B Az 180 RECIRC OUTLET RCS - Reactor Recirculation 2RPV-KBO3 - NOZISE @ N2A Az 030 RECIRC INLET RCS - Reactor Recirculation 2RPV-KB04 NOZ/SE @ N2B Az 060 RECIRC INLET RCS - Reactor Recirculation 2RPV-KBO5 NOZISE @ N2C Az 090 RECIRC INLET RCS - Reactor Recirculation 2RPV-KBO6 NOZ/SE @ N2D Az 120 RECIRC INLET RCS - Reactor Recirculation 2RPV-KBO7 NOZ/SE @ N2E Az 150 RECIRO INLET RCS - Reactor Recirculation 2RPV-KBO8 NOZ/SE @ N2F Az 210 RECIRC INLET RCS - Reactor Recirculation 2RPV-KBO9 NOZ/SE @ N2G Az 240 RECIRC INLET RCS - Reactor Recirculation 2RPV-KB1 0 NOZ/SE @ N2H Az 270 RECIRC INLET RCS - Reactor Recirculation 2RPV-KB1 1 NOZ/SE @ N2J Az 300 RECIRC INLET RCS - Reactor Recirculation 2RPV-KB12 NOZ/SE @ N2K Az 330 RECIRC INLET FWS - Feedwater 2RPV-KB1 7 NOZ/SE @ N4A Az 030 FEEDWATER FWS - Feedwater 2RPV-KB18 NOZ/SE @ N4B Az 090 FEEDWATER FWS - Feedwater 2RPV-KB19 NOZ/SE @ N4C Az 150 FEEDWATER FWS - Feedwater 2RPV-KB21 NOZ/SE @ N4E Az 270 FEEDWATER FWS - Feedwater 2RPV-KB22 NOZ/SE @ N4F Az 330 FEEDWATER CLS - Low Pressure Core Spray 2RPV-KB23 NOZJSE @ N5 Az 120 LOW PRESS CS RHS - Residual Heat Removal 2RPV-KB24 NOZ/SE @ N6A Az 045 RHR-LPCI RHS - Residual Heat Removal 2RPV-KB25 NOZ/SE @ N6B Az 135 RHR-LPCI RHS - Residual Heat Removal 2RPV-KB26 NOZ/SE @ N6C Az 315 RHR-LPCI ISC- Reactor Vessel Instrument 2RPV-KB29 NOZ/SE @ N9A Az 105 JET PUMP INSTR ISC- Reactor Vessel Instrument 2RPV-KB30 NOZ/SE @ N9B Az 285 JET PUMP INSTR CHS - High Pressure Core Spray 2RPV-KB32 NOZ/SE @ N16 Az 240 HIGH PRESS CS ISC - Reactor Vessel Instrument 2RPV-KB34 NOZ/SE @ N11 BOTTOM HEAD CLS - Low Pressure Core Spray 2RPV-KC23 SE/SEEX @ N5 Az 120 LOW PRESS CS RHS Residual Heat Removal 2RPV-KC24 SE/SEEX @ N6A Az 045 RHR-LPCI RHS Residual Heat Removal 2RPV-KC25 SE/SEEX @ N6B Az 135 RHR-LPCI RHS Residual Heat Removal 2RPV-KC26 SE/SEEX @ N6C Az 315 RHR-LPCI ISC- Reactor Vessel Instrument 2RPV-KC29 SE/PENSEAL N9A Az 105 JETPMP INSTR ISC- Reactor Vessel Instrument 2RPV-KC30 SE/PENSEAL N9B Az 285 JETPMP INSTR CHS - High Pressure Core Spray 2RPV-KC32 SE/SEEX @ N1 6 Az 240 HIGH PRESS CS R3 IS124B-7 OF IS124B-7
ATTACHMENT 3 (Enclosure to Relief Requests ISI-24A and ISI-24B)
SUPPLEMENT 10- QUALIFICATION REQUIREMENTS FOR DISSIMILAR METAL PIPING WELDS Current Requirement Proposed Change Reasoning 1.0 SCOPE Supplement 10 Is applicable to dissimilar metal piping A scope statement provides added clarity regarding the welds examined from either the inside or outside applicable range of each individual Supplement. The surface. Supplement 10 Is not applicable to piping exclusion of CRC provides consistency between welds containing supplemental corrosion resistant Supplement 10 and the recent revision to Supplement 2 clad (CRC) applied to mitigate Intergranular Stress (Reference BC 00-755). Note, an additional change Corrosion Cracking (IGSCC). 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 requirements No Change requirements listed herein, unless a set of specimens is listed herein, unless a set of specimens is designed to designed to accommodate specific limitations stated in accommodate specific limitations stated in the scope of the scope of the examination procedure (e.g., pipe size, the examination procedure (e.g., pipe size, weld joint weld joint configuration, access limitations). The same configuration, access limitations). The same specimens specimens may be used to demonstrate both detection may be used to demonstrate both detection and sizing and sizing qualification. qualification.
1.1 General. The specimen set shall conform to the 2.1 General. The specimen set shall conform to the Renumbered following requirements. following requirements.
(a)The minimum number of flaws in a test set shall be New; changed minimum number of flaws to 10 so ten sample set size for detection is consistent with length and depth sizing.
(a)Specimens shall have sufficient volume to minimize (b) Specimens shall have sufficient volume to minimize Renumbered spurious reflections that may interfere with the spurious reflections that may interfere with the interpretation process. interpretation process.
(b)The specimen set shall Include the minimum and (c) The specimen set shall include the minimum and Renumbered, metricated, the change inpipe diameter maximum pipe diameters and thicknesses for which the maximum pipe diameters and thicknesses for which the tolerance provides consistency between Supplement 10 examination procedure is applicable. Pipe diameters examination procedure Isapplicable. Pipe diameters and the recent revision to Supplement 2 (Reference BC within a range of 0.9 to 1.5 times a nominal diameter within a range of 1/2 In.(13 mm) of the nominal diameter 00-755) shall be considered equivalent. Pipe diameters larger shall be considered equivalent. Pipe diameters larger than than 24 in. shall be considered to be flat. When a range 24 In.(610 mm) shall be considered to be flat. When a of thicknesses Isto be examined, a thickness tolerance range of thicknesses Isto be examined, a thickness of *25% Is acceptable. tolerance of +/-25% Is acceptable.
(c)The specimen set shall Include examples of the (d)The specimen set shall include examples of the Renumbered, changed "condition" to "conditlons" following fabrication condition: following fabrication conditions:
Page I of 9 Enclosure
SUPPLEMENT 10 - QUALIFICATION REQUIREMENTS FOR DISSIMILAR METAL PIPING WELDS Current Requirement Proposed Change Reasoning (1) geometric conditions that normally require (1) geometric and material conditions that normally Clarification, some of the Items listed relate to material discrimination from flaws (e.g., counterbore or weld root require discrimination from flaws (e.g., counterbore or conditions rather than geometric conditions. Weld repair conditions, cladding, weld buttering, remnants of weld root conditions, cladding, weld buttering, remnants of areas were added as a result of recent field experiences.
previous welds' adjacent welds In close proximity); previous welds, adjacent welds In close proximity, and weld repair areas);
(2) typical limited scanning surface conditions (e.g.. (2) typical limited scanning surface conditions (e.g., weld Differentiates between ID and OD scanning surface diametrical shrink, single-side access due to nozzle and crowns, diametrical shrink, single-side access due to limitations. Requires that ID and OD qualifications be safe end external tapers). nozzle and safe end external tapers for outside surface conducted independently (Note, new paragraph 2.0 examinations; and Internal tapers, exposed weld (identical to old paragraph 1.0) provides for altematives roots, and cladding conditions for Inside surface when 'a set of specimens is designed to accommodate examinations). Qualification requirements shall be specific limitations stated in the scope of the satisfied separately for outside surface and Inside examination procedure.").
surface examinations.
(d) All flaws In the specimen set shall be cracks. Deleted this requirement, because new paragraph 2.3 below provides for the use of *altemative flaws' in lieu of cracks.
(1) At least 50% of the cracks shall be in austenitic 2.2 Flaw Location. At least 80% of the flaws shall be Renumbered and re-titled. Flaw location percentages material. At least 50% of the cracks In austenitic contained wholly in weld or buttering material. At least one redistributed because field experience indicates that material shall be contained wholly in weld or buttering and a maximum of 10% of the flaws shall be in ferrItic flaws contained in weld or buttering material are material. At least 10% of the cracks shall be in ferritic base material. At least one and a maximum of 10% of probable and represent the more stringent ultrasonic material. The remainder of the cracks may be in either the flaws shall be In austenitic base material. detection scenario.
austenitic or ferritic material.
(2) At least 50% of the cracks In austenitic base 2.3 Flaw Type. Renumbered and re-titled. Altemative flaws are required material shall be either IGSCC or thermal fatigue (a) At least 60% of the flaws shall be cracks, the for placing axial flaws in the HAZ of the weld and other-cracks. At least 50% of the cracks In ferritic material remainder shall be alternative flaws. Specimens with areas where implantation of a crack produces shall be mechanically or thermally induced fatigue IGSCC shall be used when available. Alternative flaws, metallurgical conditions that result in an unrealistic cracks. If used, shall provide crack-like reflective ultrasonic response. This is consistent with the recent characteristics and shall be limited to the case where revision to Supplement 2 (Reference BC 00-755).
implantation of cracks produces spurious reflectors that are uncharacteristic of actual flaws. Alternative The 40% limit on alternative flaws is needed to support flaw mechanisms shall have a tip width of less than or the requirement for up to 70% axial flaws. Metricated equal to 0.002 In. (.05 mm).
(3) At least 50% of the cracks shall be coincident with (b) At least 50% of the flaws shall be coincident with Renumbered. Due to Inclusion of alternative flaws', use areas described in (c) above. areas described in 2.1 (d) above. of "cracks" is no longer appropriate.
Page 2 of 9 Enclosure
SUPPLEMENT 10-QUALIFICATION REQUIREMENTS FOR DISSIMILAR METAL PIPING WELDS Current Requirement Proposed Change Reasoning 2.4 Flaw Depth. All flaw depths shall be greater than 10% Moved from old paragraph 1.3(c) and 1.4 and re-titled.
of the nominal pipe wall thickness. Flaw depths shall Consistency between detection and sizing specimen set exceed the nominal clad thickness when placed In requirements (e.g.. 20% vs. 1/3 flaw depth Increments, cladding. Flaws In the sample set shall be distributed e.g., original paragraph 1.3(c))
as follows:
Flaw Depth Minimum
(% WaU 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 shall Renumbered and re-titled and moved to paragraph Include detection specimens that meet the following 3.1 (a). No other changes requirements.
(a) Specimens shall be divided into grading units. Each Renumbered to paragraph 3.1(a)(1). No other changes.
grading unit shall 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.
(b) Detection sets shall be selected from Table VlIl-S2- Moved to new paragraph 3.1 (a)(2).
- 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 following criteria Flaw depth requirements moved to new paragraph 2.4, for flaw depth, orientation, and type. flaw orientation requirements moved to new paragraph 2.5, flaw type requirements moved to new paragraph
__________ _ _ _ _2.3,
___ 'Flaw Type."
Page 3 of 9 Enclosure
SUPPLEMENT 10-QUALIFICATION REQUIREMENTS FOR DISSIMILAR SUMETAL PIPING WELDS Q E Current Requirement ProposedChange Reasoning (1) All flaw depths shall be greater than 10% of the Deleted, for consistency In sample sets the depth nominal pipe wall thickness. At least 1/3 of the flaws, distribution Is the same 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 70% of the flaws, 2.5 Flaw Orlentatlon. Note, this distribution is applicable for detection and rounded to the next higher whole number, shall be (a) At least 30% and no more than 70% of the flaws, depth sizing. Paragraph 2.5(b)(1) requires that all length-oriented axially. The remainder of the flaws shall be rounded to the next higher whole number, shall be sizing flaws be oriented circumferentially.
oriented circumferentially. oriented axially. The remainder of the flaws shall be oriented circumferentlally.
-1 1.3 Length Sizing Specimens. The specimen set shall Renumbered and re-titled and moved to new paragraph - I Include length sizing specimens that meet the following 3.2 I requirements. I (a)All length sizing flaws shall be oriented Moved, included in new paragraph 3.2(a) i circumferentially.
'I (b) The minimum number of flaws shall be ten. Moved, Included in new paragraph 2.1 above (c) All flaw depths shall be greater than 10% of the Moved, included in new paragraph 2.4 above after I nominal pipe wall thickness. At least 1/3 of the flaws, revision for consistency 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 specimen set shall Moved, included in new paragraphs 2.1, 2.3, 2.4 include depth sizing specimens that meet the following requirements.
(a)The minimum number of flaws shall be ten. Moved, included In new paragraph 2.1 (b) Flaws in the sample set shall not be wholly Moved, potential conflict with old paragraph 1.2(c)(1);
contained within cladding and shall be distributed as 'However, flaw depths shall exceed the nominal clad follows: thickness when placed In cladding.". Revised for clarity and included in new paragraph 2.4 Page 4 of 9 Enclosure
SUPPLEMENT 10- QUALIFICATION REQUIREMENTS FOR DISSIMILAR METAL PIPING WELDS Current Requirement Proposed Change Reasoning Flaw Depth Minimum Moved, included in paragraph 2.4 for consistent
(%Wall Thickness) Number of Flaws applicability to detection and sizing samples.
10-30% 20%
31-60% 20%
61-100% 20%
The remaining flaws shall be Inany of the above categories.
(b) Sizing Specimen sets shall meet the following Added for clarity 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 In 2.5(a). Included for clarity. Previously addressed 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 identification shall be For qualifications from the outside surface, the Differentiate between qualifications conducted from the concealed from the candidate. All examinations shall be specimen Inside surface and Identification shall be outside and Inside surface.
completed prior to grading the results and presenting concealed from the candidate. When qualificatIons are the results to the candidate. Divulgence of particular performed from the Inside surface, the flaw location specimen results or candidate viewing of unmasked and specimen Identification shall be obscured to specimens after the performance demonstration is maintain a "blind test." All examinations shall be prohibited. completed prior to grading the results and presenting the results to the candidate. Divulgence of particular specimen results or candidate viewing of unmasked specimens after the performance demonstration Isprohibited.
2.1 DetectIon Test. Flawed and unflawed grading units 3.1 Detection Qualification. Renumbered, moved text to paragraph 3.1 (a)(3) shall be randomly mixed (a)The specimen set shall include detection specimens Renumbered, moved from old paragraph 1.2.
that meet the following requirements.
Page 5 of 9 Enclosure
SUPPLEMENT 10- QUALIFICATION REQUIREMENTS FOR DISSIMILAR METAL PIPING WELDS Current Requirement Proposed Change Reasoning (1) Specimens shall be divided into grading units. Each Renumbered, moved from old paragraph 1.2(a).
grading unit shall include at least 3 in. (76 mm) of weld Metricated. No other changes.
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 Table Vill-S1O-1. Moved from old paragraph 1.2(b). Table revised to The number of unflawed grading units shall be at least reflect a change in the minimum sample set to 10 andc one and a half times the number of flawed grading units. the application of equivalent statistical false call parameters to the reduction In unflawed grading units.
Human factors due to large sample size.
(3) flawed and unflawed grading units shall be randomly Moved from old paragraph 2.1 mixed.
(b) Examination equipment and personnel are qualified for Moved from old paragraph 3.1. Modified to reflect the detection when personnel demonstrations satisfy the 100% detection acceptance criteria of procedures acceptance criteria of Table ViIl S1O-1 for both detection versus personnel and equipment contained in new and false calls. paragraph 4.0 and the use of 1.5X rather than 2X unflawed grading units contained in new paragraph 3.1 (a)(2). Note, the modified table maintains the screening criteria of the original Table VIII-S2-1.
2.2 Length Sizing Test 3.2 Length Sizing Test Renumbered (a) The length sizing test may be conducted separately (a) Each reported circumferential flaw In the detection Provides consistency between Supplement 10 and the--
or in conjunction with the detection test. test shall be length sized. recent revision to Supplement 2 (Reference BC 00-755).
(b) When the length sizing test is conducted in (b) When the length sizing test is conducted in conjunction Change made to ensure security of samples, consistent conjunction with the detection test, and less than ten with the detection test, and less than ten circumferential with the recent revision to Supplement 2 (Reference BC circumferential flaws are detected, additional specimens flaws are detected, additional specimens shall be provided 00-755).
shall be provided to the candidate such that at least ten to the candidate such that at least ten flaws are sized. The flaws are sized. The regions containing a flaw to be regions containing a flaw to be sized may be identified to Note, length and depth sizing use the term 'reglons' sized shall be identified to the candidate. The candidate the candidate. The candidate shall determine the length of while detection uses the term grading units." The two shall determine the length of the flaw in each region. the flaw in each region. terms define different concepts and are not intended to be equal or interchangeable.
(c) For a separate length sizing test, the regions of each (c) For a separate length sizing test, the regions of each Change made to ensure security of samples, consistent specimen containing a flaw to be sized shall be specimen containing a flaw to be sized may be identifIed with the recent revision to Supplement 2 (Reference BC identified to the candidate. The candidate shall to the candidate. The candidate shall determine the length 00-755).
determine the length of the flaw in each region of the flaw in each region.
Page 6 of 9 Enclosure
SUPPLEMENT 10- QUALIFICATION REQUIREMENTS FOR DISSIMILAR METAL PIPING WELDS Current Requirement Proposed Change Reasoning (d) Examination procedures, equipment, and personnel Moved from old paragraph 3.2(a) includes Inclusion of are qualified for length sizing when the RMS error of the 'when' as an editorial change.
flaw length measurements, as compared to the true flaw Metricated.
lengths, Isless than or equal to 0.75 in. (19 mm).
2.3 Depth Sizing Test 3.3 Depth Sizing Test Renumbered (a) For the depth sizing test, 80% of the flaws shall be (a)The depth sizing test may be conducted separately Change made to ensure security of samples, consistent sized at a specific location on the surface of the or In conjunction with the detection test For a with the recent revision to Supplement 2 (Reference BC specimen identified to the candidate. separate depth sizing test, the regions of each 00-755).
specimen containing a flaw to be sized may be Identifled to the candidate. The candidate shall determine the maximum depth of the flaw In each region.
(b) For the remaining flaws, the regions of each (b) When the depth sizing test Is conducted In Change made to be consistent with the recent revision specimen containing a flaw to be sized shall be conjunction with the detection test, and less than ten to Supplement 2 (Reference BC 00-755).
identified to the candidate. The candidate shall flaws are detected, additional specimens shall be determine the maximum depth of the flaw In each provided to the candidate such that at least ten flaws Changes made to ensure security of samples, region. are sized. The regions of each specimen containing a consistent with the recent revision to Supplement 2 flaw to be sized may be identified to the candidate. The (Reference BC 00-755).
candidate shall determine the maximum depth of the flaw in each region.
(c) Examination procedures, equipment, and personnel Moved from old paragraph 3.2(b). Metricated.
are qualified for depth sizing when the RMS error of the flaw depth measurements, as compared to the true flaw depths, is less than or equal to 0.125 in. (3 mm).
Delete as a separate category. Moved to new paragraph 3.0 ACCEPTANCE CRITERIA detection (3.1) and sizing 3.2 and 3.3 3.1 Detection Acceptance Criteria. Examination Moved to new paragraph 3.1 (b), reference changed to procedures, equipment, and personnel are qualified for Table SIO from S2 because of the change in the detection when the results of the performance minimum number of flaws and the reduction in unflawed demonstration satisfy the acceptance criteria of Table grading units from 2X to 1.5X.
Vill-S2-1 for both detection and false calls.
3.2 Sizing Acceptance Criteria Deleted as a separate category. Moved to new paragraph on length 3.2 and depth 3.3 (a) Examination procedures, equipment, and personnel Moved to new paragraph 3.2(d), Included word 'when' are qualified for length sizing the RMS error of the flaw as an editorial change.
length measurements, as compared to the true flaw lengths, is less than or equal to 0.75 Inch.
Page 7 of 9 Enclosure
SUPPLEMENT 10 - QUALIFICATION REQUIREMENTS FOR DISSIMILAR METAL PIPING WELDS Current Requirement Proposed Change Reasoning (b)Examination procedures, equipment, and personnel Moved to new paragraph 3.3(c) 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 following New. Based on experience gained inconducting additional requirements. qualifications, the equivalent of 3 personnel sets (i.e., a (a)The specimen set shall Include the equivalent of at minimum of 30 flaws) is required to provide enough least three personnel sets. Successful personnel flaws to adequately test the capabilities of the demonstrations may be combined to satisfy these procedure. Combining successful demonstrations requirements. allows a variety of examiners to be used to qualify the (b) Detectability of all flaws within the scope of the procedure. Detectability of each flaw within the scope of procedure shall be demonstrated. Length and depth the procedure is required to ensure an acceptable sizing shall meet the requirements of paragraph 3.2 personnel pass rate. The last sentence is equivalent to and 3.3. the previous requirements and is satisfactory for (c) At least one successful personnel demonstration expanding the essential variables of a previously has been performed. qualified procedure (d) To qualify new values of essential variables, at least one personnel qualification set Is required.
Page 8 of 9 Enclosure
SUPPLEMENT 10 - QUALIFICATION REQUIREMENTS FOR DISSIMILAR METAL PIPING WELDS Current Requirement I Proposed Change I ReasonIn I 10 TABLE Vill-S2-1 PERFORMANCE DEMONSTRATION DETECTION TEST ACCEPTANCE CRITERIA Detection Test False Call test Acceptance Criteria Acceptance Criteria No. of Minimum No. of Maximum Flawed Detection Unflawed Number of Grading Criteria Grading False Calls Units Units C G 12 1
_4 10 8 :2 15 8 2 11 9 2- 17 8-3 12 9 24 18 8 3 13 10 26-20 4 3 14 10 26 21 63 15 11 80 23 63 16 12 82 24 6 4 17 12 84 26 fi 4 18 13 86 27 4 19 13 86-29 20 14 4J-30 685 Page 9 of 9 Enclosure