ML12341A278
| ML12341A278 | |
| Person / Time | |
|---|---|
| Site: | San Onofre  |
| Issue date: | 12/04/2012 |
| From: | St.Onge R Southern California Edison Co |
| To: | Document Control Desk, Office of Nuclear Reactor Regulation |
| References | |
| Download: ML12341A278 (50) | |
Text
ISOUTHERN EDISON CALIFORNIA Richard J. St. Onge Director, Nuclear Regulatory Affairs and Emergency Planning An EDISON INTERNATIONAL'& Company December 4, 2012 10 CFR 50.55a U. S. Nuclear Regulatory Commission Attn: Document Control Desk Washington, DC 20555-0001
SUBJECT:
Docket Nos. 50-361 and 50-362 Relief Request: American Society of Mechanical Engineers (ASME)
Code Case N-770-1 San Onofre Nuclear Generating Station (SONGS), Units 2 and 3
Dear Sir or Madam:
Pursuant to 10 CFR 50.55a(a)(3)(ii), Southern California Edison (SCE) requests relief from the requirement of 10 CFR 50.55a(g)(6)(ii)(F)(3) that essentially 100% coverage be achieved for the required baseline volumetric examination specified in ASME Code Case N-770-1. The details and justification for this request are provided in the enclosures to this letter.
SCE requests approval of this relief to support the SONGS Unit 2 cycle 18 and SONGS Unit 3 cycle 17 refueling outages. These refueling outages will be the first refueling after baseline examination requirements of 10 CFR 50.55a(g)(6)(ii)(F) are applicable.
The next refueling outages are not expected to occur prior to January 2014.
This letter and the enclosures contain no new commitments. Should you have any questions, please contact the Manager of Plant Licensing, Ms. Linda T. Conklin at (949) 368-9443.
Sincerely,
Enclosures:
(1) Proposed Alternative in Accordance with 10 CFR 50.55a(a)(3)(ii), Hardship or Unusual Difficulty without Compensating Increase in Level of Quality or Safety (2) Volumetric Examination Coverage of SONGS Units 2 & 3 Dissimilar Metal Weld Configurations cc: E. E Collins, Regional Administrator, NRC Region IV R. Hall, NRC Project Manager, SONGS Units 2 and 3 B. Benney, NRC Project Manager, SONGS Units 2 and 3 G. G. Warnick, NRC Senior Resident Inspector, SONGS Units 2 and 3 P.O. Box 128 Akoc-r San Clemente, CA 92672
Enclosure 1 San Onofre Nuclear Generation Station (SONGS) Units 2 and 3 Proposed Alternative in Accordance with 10 CFR 50.55a(a)(3)(ii)
Hardship or Unusual Difficulty without Compensating Increase in Level of Quality or Safety
Enclosure 1 SONGS Units 2 and 3 Proposed Alternative in Accordance with 10 CFR 50.55a(a)(3)(ii)
Hardship or Unusual Difficulty without Compensating Increase in Level of Quality or Safety
- 1. ASME Code Component(s) Affected The Class 1 pressure retaining dissimilar metal piping welds containing Alloy 82/182 listed in tables 2 and 3 are subject to American Society of Mechanical Engineers (ASME) Code Case N-770-1, Table 1, Examination Category, Inspection Item B - Unmitigated butt weld at cold leg operating temperature
- 2. Applicable Code Edition and Addenda The ASME Boiler and Pressure Vessel Code, Rules for Inservice Inspection of Nuclear Power Plant Components,Section XI, 1995 Edition with Addenda through 1996 [1] as amended by 10 CFR 50.55a [2] is the code of record for the San Onofre Nuclear Generation Station (SONGS) Units 2 and 3, third 10-year In-service Inspection (ISI) interval.
10 CFR 50.55a(g)(6)(ii)(F)(1), effective date August 22, 2011, requires "licensees of existing, operating pressurized-water reactors as of July 21, 2011 shall implement the requirements of ASME Code Case N-770-1, subject to the conditions specified in paragraphs (g)(6)(ii)(F)(2) through (g)(6)(ii)(F)(10) of this section, by the first refueling outage after August 22, 2011 "
Additionally, 10 CFR 50.55a(g)(6)(ii)(F)(3) states that the baseline examinations for welds in Code Case N-770- 1, Table 1, Inspection Item B, "shallbe completed by the end of the next refueling outage after January20, 2012. Previous examinations of these welds can be creditedfor baseline examinations if they were performed within the re-inspectionperiod for the weld item in Table 1 using Section X1, Appendix VIII requirementsand met the Code required examination volume of essentially 100 percent. Otherprevious examinations that do not meet these requirementscan be used to meet the baseline examination requirement, provided NRC approval of alternative inspection requirements in accordancewith paragraphs(a)(3)(i) or (a)(3)(ii) of this section is grantedprior to the end of the next refueling outage after January20, 2012."
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Enclosure 1 SONGS Units 2 and 3 Proposed Alternative in Accordance with 10 CFR 50.55a(a)(3)(ii)
Hardship or Unusual Difficulty without Compensating Increase in Level of Quality or Safety
- 3. Applicable Code Requirement ASME Code Case N-770-1 as Amended by 10 CFR 50.55a(g)(6)(ii)(F)
CLASS 1 PWR Pressure Retaining Dissimilar Metal Piping and Vessel Nozzle Butt Welds Containing Alloy 82/182 Parts Examined Inspection Extent and Frequency of Examination Item Unmitigated butt weld Bare metal visual examination once per interval at Cold Leg operating B temperature Essentially 100% volumetric examination for
(-2410) axial and circumferential flaws in accordance with the applicable requirements of ASME
> 525°F (274°C) Section XI, Appendix VIII, every second
< 580'F (304 0 C) inspection period not to exceed 7 years. Baseline examinations shall be completed by the end of the next refueling outage after January 20, 2012.
As defined by ASME Code Case N-460 [3] essentially 100% means greater than 90% of the examination volume of each weld where reduction in coverage is due to interference by another component or part geometry.
ASME Section X1, Appendix VIII, Supplement 10, "Qualification Requirements for Dissimilar Metal Piping Welds" is applicable to dissimilar metal welds without cast materials. ASME Section Xl, Appendix VIII, Supplement 9 states that the qualification requirements for the examination of cast stainless steel are "in the course of preparation".
- 4. Reason for Request Southern California Edison (SCE) is requesting permission to utilize the Ultrasonic examinations performed in accordance with MRP-139 [4] during the October 2009 SONGS Unit-2 cycle- 16, and the October-November 2010 SONGS Unit-3 Cycle- 16 refueling outages to satisfy the baseline examination requirements of 10 CFR 50.55a(g)(6)(ii)(F)(3).
Those examinations will have been performed within the re-inspection period for the ASME Code Case N-770-1, Inspection Item B welds for the proposed duration of this Relief.
However, the examinations did not satisfy the required volume coverage of ASME Code Case N-770-1, as amended by 10 CFR 50.55a(g)(6)(ii)(F)(3) due to the weld configuration and permanent obstructions. These scanning limitations prohibited essentially 100%
examination coverage of the required volume. Additional weld surface conditioning would 2
Enclosure 1 SONGS Units 2 and 3 Proposed Alternative in Accordance with 10 CFR 50.55a(a)(3)(ii)
Hardship or Unusual Difficulty without Compensating Increase in Level of Quality or Safety not improve the examination coverage. No SONGS refueling outages have initiated after January 9, 2012.
10 CFR 50.55a(g)(6)(ii)(F)(4) provides the following exception to ASME Code Case N-770-1, "the axial examination coverage requirements of -2500(c) may not be considered to be satisfied unless essentially 100 percent coverage is achieved."
Relief is requested from the 10 CFR 50.55a(g)(6)(ii)(F)(4) exception to ASME Code Case N-770-1 that essentially 100% coverage be achieved for the baseline volumetric examinations.
- 5. Proposed Alternative and Basis for Use Proposed Alternative
- 1) Conduct ultrasonic examinations in accordance with 10 CFR 50.55a(g)(6)(ii)(F) to the maximum extent possible.
- 2) Perform periodic system pressure tests in accordance with ASME Section XI Category B-P, Table IWB-2500-1.
- 3) Perform bare metal visual examinations of the Inspection Item B welds in accordance with ASME Code Case N-722-1 and N-770-1. These examinations were last performed during the SONGS Units 2 and 3 cycle 16 Refueling outages. No evidence of leakage from these components has been observed.
- 4) Perform engineering walkdowns of Class 1, Boric Acid systems inside containment during each refueling outage. This walkdown is performed to look for system anomalies that could indicate degradation or affect plant performance. These examinations identified no evidence of leakage for these components.
The combination of these examinations provides confidence that an acceptable level of quality and safety has been maintained.
Basis Each SONGS unit employs four reactor coolant pumps. Each reactor coolant pump suction and discharge pipe consists of a 30-inch inside diameter mill-clad SA-516, Grade 70 carbon steel pipe joined to a SA-35 1, Grade CF8M cast stainless steel safe end using an unmitigated Alloy 182 dissimilar metal weld. In addition, each SONGS unit employs four carbon steel SA-182 forged Emergency Core Cooling System (ECCS) injection nozzles joined to a SA-35 1, Grade CF8M cast stainless steel safe end also using an unmitigated Alloy 182 dissimilar metal weld. All twelve dissimilar metal welds in each SONGS unit are categorized in Code Case N-770-1 as Inspection Item-B.
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Enclosure 1 SONGS Units 2 and 3 Proposed Alternative in Accordance with 10 CFR 50.55a(a)(3)(ii)
Hardship or Unusual Difficulty without Compensating Increase in Level of Quality or Safety All of the welds covered by this relief request are found in cold leg temperature (T-cold) regions of the system. This means there is a lower probability of Primary Water Stress Corrosion Cracking (PWSCC) crack initiation, and a slower crack growth rate. These welds are also very highly flaw tolerant, as demonstrated in the MRP-109 report.[5]. No service-induced flaws have been found in similar large diameter cold leg welds, even though most plants of interest have been in service for over 25 years. [6,7]
During each of the SONGS Unit-2 and 3 cycle 16 refueling outages, volumetric examinations were performed on the eight (8) reactor coolant pump inlet/outlet pipe safe end dissimilar welds and on the four (4) cold leg ECCS inject nozzle dissimilar metal safe end welds utilizing a conventional non-encoded Ultrasonic (UT) technique. These examinations typically employed a team scanning approach. The proposed baseline examinations were all performed by a qualified Level III examiner. In all cases, the examinations were performed from the carbon steel side of the weld. No reportable indications were detected in these examinations.
The examination probes, instrumentation and procedures, were qualified through the Electric Power Research Institute (EPRI) Performance Demonstration Initiative (PDI) blind demonstration process in accordance with the requirements of ASME Section XI, Appendix VIII, Supplement 10 consistent with Revision C of PDI Generic Procedure for the Ultrasonic Examination of Dissimilar Metal welds, PDI-UT-10. This qualification did not use site specific mockups. Examination personnel were qualified through the PDI program.
Individual examiner qualifications may not have included examination of the representative mockups for the specific component examinations subject to this request.
These welds had previously been examined during the second ISI Interval for SONGS Units 2 and 3. Those prior examinations employed conventional non-encoded techniques consistent with the 1989 Edition of ASME Section XI, Appendix III. No recordable indications were detected in those previous examinations.
In addition to these ultrasonic examinations, a complete bare metal visual examination was performed in accordance with ASME Code Case N-722.
Prior to the 10 CFR 50.55a(g)(6)(ii)(F) effective date of August 22, 2011, the Materials Reliability Program (MRP) issued "Primary System Piping Butt Weld Inspection and Evaluation Guidelines (MRP-139)" that guidance included mandatory elements per the implementation protocol of the Nuclear Energy Institute (NEI) 03-08 initiative. That MRP guideline provided a strategy to manage degradation of butt welds with alloy 82/182 in primary system piping that are 1" nominal pipe size or greater and exposed to temperatures greater than or equal to cold leg temperature. The guideline was structured to categorize weld inspections to acknowledge mitigation, temperature, safety significance of flaw orientation, and inspection capabilities. The guideline defined examination locations on the piping, examination requirements for various weld categories, and extent of examination for 4
Enclosure 1 SONGS Units 2 and 3 Proposed Alternative in Accordance with 10 CFR 50.55a(a)(3)(ii)
Hardship or Unusual Difficulty without Compensating Increase in Level of Quality or Safety each location. Finally, the guideline provided evaluation procedures to determine acceptance of flaws, justification for mitigation actions, and changing examination categories.
The weld examination volume required by MRP-139[4] is the same as in ASME Code Case N-770-1 for unmitigated cold leg dissimilar metal welds except that examination of Cast Austenitic Stainless Steel (CASS) material within the described volume is not required.
MRP-139 delineated acceptable coverage of the required examination volume to be calculated separately for axial and circumferential flaw orientations using the actual weld configuration and the procedure's essential variables. Coverage calculations could be made by manual plotting or by using computer-aided design (CAD) or other software that models the procedure's beam angles and scan plans. The inspection was considered complete when, using the qualified procedure and personnel, the coverage for both axial and circumferential flaws was greater than 90% of the required examination volume.
If >90% coverage for circumferential or axial flaws using qualified personnel and procedures was not attained then the following supplemental actions were required:
- If greater than 90% coverage for circumferential flaws could not be met, then an evaluation to demonstrate flaw tolerance within the missed examination volume, and a supplemental visual weld examination schedule during subsequent refueling outages was required. In addition, enhanced Reactor Coolant System (RCS) leakage monitoring consistent with existing Pressurized Water Reactor Owners Group guidelines under NEI 03-08 was required.
- If greater than 90% coverage for axial flaws could not be met, but greater than 90%
coverage was obtained for circumferential flaws, then the examination for axial flaws would be completed to achieve the maximum coverage possible with limitations noted in the examination report.
Each weld addressed in this Relief Request includes a CASS safe end within the examination volume. There currently is no available Appendix VIII supplement for examination of CASS. MRP-139 revision 1 allowed exclusion of CASS material from required examination volumes. The cycle 16 refueling outage examinations coverage for axial flaws in the subject welds did not attain the MRP- 139[4] requirement of >90%. The cycle-16 refueling outage examinations did meet MRP-139 [4] coverage requirements for circumferential flaws except for the reactor coolant pump discharge welds in coolant loops IA, 1B and 2A. In accordance with the MRP-139[4] requirements, SCE documented the examination limitations and implemented visual examinations, leakage monitoring, and performed analysis of the Reactor Coolant Pump (RCP) discharge welds to validate flaw tolerance results consistent with the MRP-109 conclusions.
Table-I shows the combined axial and circumferential flaw examination coverage achieved for the ASME Code Case N-770-1 and for the PWSCC susceptible materials within that volume. Transducer skewing was used in accordance with PDI-UT-10 requirements; however no examination credit has been taken for volumes that were examined only by 5
Enclosure 1 SONGS Units 2 and 3 Proposed Alternative in Accordance with 10 CFR 50.55a(a)(3)(ii)
Hardship or Unusual Difficulty without Compensating Increase in Level of Quality or Safety transducer skewing. Paragraph 2500(b) of ASME Code Case N-770-1 addresses treatment of CASS within the required examination volume. Examinations conducted using Appendix VIII qualified procedures provide reasonable assurance for the detection of flaws within the cast side of dissimilar metal welds, even though there is no approved Appendix VIII supplement for these materials.
The examination coverage reported in Table-I for ASME Code Case N-770-1 reflects credit for the CASS volume that was interrogated using Appendix VIII, Supplement-10 methods as described in paragraph 2500 (b) of the Code Case. Table 1 also reports examination coverage within the PWSCC susceptible material (exclusive of CASS, Carbon Steel and Stainless Steel cladding). As documented in the table, examination volume requirements could not be met.
Table-i ASME Code Case N-770-1 PWSCC Susceptible Material Examination Coverage Examination Coverage RCP Suction (Typical of All 4)
RCP Discharge 45.2% 38.7%
Unit 2 & 3 loop 1A RCP Discharge 50.5% 44.0%
Unit 2 & 3 loop 1B RCP Discharge 50.5% 44.0%
Unit 2 & 3 loop 2A RCP Discharge 55.8% 49.3%
Unit 2 & 3 loop 2B Cold Leg ECCS (Typical of All 4)
(1) The listed N-770-1 values credit coverage for CASS volumes that were examined using methods that were qualified in accordance with ASME Section XI, Appendix VIII, for Supplement 10 application Enclosure (2) provides the Ultrasonic examination coverage analysis for SONGS Units 2 and 3. The amount of coverage that could be credited was determined in accordance with the qualified examination procedure utilizing weld design drawings and field obtained contours. Tables 2 and 3 summarize the axial and circumferential flaw examination coverage for Code Case N-770-1 paragraph 2500(b), and for the PWSCC susceptible volumes for SONGS Units 2 and 3, respectively.
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Enclosure 1 SONGS Units 2 and 3 Proposed Alternative in Accordance with 10 CFR 50.55a(a)(3)(ii)
Hardship or Unusual Difficulty without Compensating Increase in Level of Quality or Safety Table 2 SONGS Unit-2 Volumetric Examination Coverage Cold Leg Last Next N-770-1 Coverage Susceptible Volume Coverage Weld Location ISI weld ID Examination Required ) Axial Circ. Axial Circ.
Examination Flaws Flaws (3) Flaws Flaws C.L. 1A 02-009-012 Oct 2009 Oct 2016 32.0% 89.8% (2) 29.3 100%
ECCS 1B 02-011-011 Oct 2009 Oct 2016 32.0% 89.8% (2) 29.3 100%
2A 02-013-011 Oct 2009 Oct 2016 32.0% 89.8% (2) 29.3 100%
2B 02-015-010 Oct 2009 Oct 2016 32.0% 89.8% (2) 29.3 100%
C.L RCP 1A 02-008-002 Oct 2009 Oct 2016 23.1% 100% 10.4% 100%
Suction 1B 02-010-002 Oct 2009 Oct 2016 23.1% 100% 10.4% 100%
2A 02-012-002 Oct 2009 Oct 2016 23.1% 100% 10.4% 100%
2B 02-014-002 Oct 2009 Oct 2016 23.1% 100% 10.4% 100%
C.L. RCP 1A 02-009-002 Oct 2009 Oct 2016 20.2% 70.3% 7.9% 70.3%
Discharge 1B 02-011-002 Oct 2009 Oct 2016 20.2% 80.8% 7.9% 80.8%
2A 02-013-002 Oct 2009 Oct 2016 20.2% 80.8% 7.9% 80.8%
2B 02-015-002 Oct 2009 Oct 2016 20.2% 91.4% 7.9% 91.4%
Notes
- 1. N-770-1 re-inspection period for Inspection Item B is every second inspection period not to exceed 7-years
- 3. Values include CASS volumes examined using methods qualified in accordance with Appendix VIII, Supplement 10 7
Enclosure 1 SONGS Units 2 and 3 Proposed Alternative in Accordance with 10 CFR 50.55a(a)(3)(ii)
Hardship or Unusual Difficulty without Compensating Increase in Level of Quality or Safety Table 3 SONGS Unit-3 Volumetric Examination Coverage Cold Leg Last Next N-770-1 Coverage Susceptible Volume Coverage Weld Location ISI weld ID Examination Required (1) Axial Circ. Axial Circ.
Examination Flaws Flaws (3) Flaws Flaws C.L. 1A 03-011-011 Oct 2010 Oct 2017 32.0% 89.8% (2) 29.3 100%
ECCS 1B 03-009-012 Nov 2010 Nov 2017 32.0% 89.8% (2) 29.3 100%
2A 03-015-010 Nov 2010 Nov 2017 32.0% 89.8% (2) 29.3 100%
2B 03-013-011 Nov 2010 Nov 2017 32.0% 89.8% (2) 29.3 100%
C.L. RCP 1A 03-010-002 Oct 2010 Oct 2017 23.1% 100% 10.4% 100%
Suction 1B 03-008-002 Oct 2010 Oct 2017 23.1% 100% 10.4% 100%
2A 03-014-002 Oct 2010 Oct 2017 23.1% 100% 10.4% 100%
2B 03-012-002 Oct 2010 Oct 2017 23.1% 100% 10.4% 100%
C.L. RCP 1A 03-011-002 Oct 2010 Oct 2017 20.2% 70.3% 7.9% 70.3%
Discharge 1B 03-009-002 Nov 2010 Nov 2017 20.2% 80.8% 7.9% 80.8%
2A 03-015-002 Nov 2010 Nov 2017 20.2% 80.8% 7.9% 80.8%
2B 03-013-002 Nov 2010 Nov 2017 20.2% 91.4% 7.9% 91.4%
Notes
- 1. N-770-1 re-inspection period for Inspection Item B is every second inspection period not to exceed 7-years
- 3. Values include CASS volumes examined using methods qualified in accordance with Appendix VIII, Supplement 10 Tables 2 and 3 show that examination coverage for axial flaws in RCP suction, RCP discharge and ECCS injection nozzle welds were significantly impacted by design weld geometries. Examination for circumferential flaws in ECCS injection and RCP suction welds were limited only in non PWSCC susceptible CASS material. However, examination coverage for circumferential flaws in RCP discharge welds was obstructed by Resistance Temperature Detector (RTD) thermowells and by pressurizer spray and charging pipe nozzles. This obstruction precluded full examination of the PWSCC susceptible material for circumferential flaws in RCP discharge piping welds.
As identified in MRP-109 [5], the axial flaw(s) that could result from a PWSCC mechanism in the susceptible alloy 82/182 butt weld are not safety significant because critical axial flaw lengths exceed the PWSCC susceptible axial weld lengths by significant margins.
Specifically, the critical axial flaw length for an RCP inlet or outlet alloy 82/182 butt weld is 38.2" (MRP-109 Table 5-2) which exceeds the actual widths of 1.4" - 3.0" for the SONGS Units 2 and 3 RCP inlet and outlet welds. MRP-109 also addressed Combustion Engineering ECCS Safety Injection nozzle dissimilar metal welds. Critical flaw size analyses were performed and reported for welds considered to be limiting. Table 5-2 of MRP- 109 does not specifically provide the critical axial flaw length for ECCS Safety Injection nozzles. However, it can be concluded from this table that the axial weld lengths 8
Enclosure 1 SONGS Units 2 and 3 Proposed Alternative in Accordance with 10 CFR 50.55a(a)(3)(ii)
Hardship or Unusual Difficulty without Compensating Increase in Level of Quality or Safety of 1.6"-2.5" for ECCS nozzles at SONGS are substantially shorter than the most limiting reported critical axial flaw length of 7.2" for all Combustion Engineering designed welds.
In conclusion, an undetected, critical PWSCC axial flaw in an ECCS Safety Injection nozzle or an RCP suction or discharge weld is not credible and therefore plant modifications to improve axial flaw examination coverage would not result in an increase in safety.
Examinations of the 115" circumference RCP discharge welds resulted in circumferential flaw examination gaps caused by RTD and attached piping obstructions. The maximum obstructed circumferential length of 12.1" results from pressurizer spray and charging line attachments (Enclosure 2). The minimum critical circumferential flaw length calculated for these welds is 38.2" as shown in MRP-109 Table 5-2. The MRP-190 Table 5-5 report and confirmatory analyses required by MRP- 139[4] demonstrate that the time required for an undetected PWSCC to grow from a readily detectable through wall leakage rate, to the critical length, is well in excess of the Code Case N-770-1 re-inspection interval. Therefore an undetected critical PWSCC circumferential flaw in an RCP discharge weld is not credible and improving the exam axial flaw examination volume coverage would not result in an increase in safety.
As stated above, the initiation and growth of a safety significant flaw in a cold leg alloy 82/182 dissimilar metal butt weld is extremely unlikely. However, as an added measure of safety, the industry imposed an NEI-03-08 "needed" requirement, to improve their RCS leak detection capability in part due to the concern with PWSCC. SONGS Units 2 and 3 have adopted the standardized approach to measuring RCS leak rate in WCAP- 16423 [8] and the action levels in WCAP-16465 [9]. These enhanced leak rate monitoring and detection capabilities ensure that if a PWSCC flaw were to grow through wall, although unlikely, it would be detected prior to reaching a safety significant size.
Examination coverage was limited by permanent obstructions and by the design geometry of the outer diameter weld surface. There are no currently qualified procedures or surface conditioning that would substantially improve examination coverage beyond that attained during the cycle- 16 refueling outages. However, the EPRI NDE Center has established initiatives to improve examination technology and procedures. SCE is committed through the PDI program and NEI 03-08 to support and implement examination improvements as they become available.
Therefore, the refueling outage 16 examinations performed to meet MRP-139 combined with the periodic system pressure tests, N-770-1 visual examinations, leakage monitoring and outage system walk downs provide an acceptable level of quality and safety for identifying degradation from PWSCC prior to a safety significant flaw developing.
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Enclosure 1 SONGS Units 2 and 3 Proposed Alternative in Accordance with 10 CFR 50.55a(a)(3)(ii)
Hardship or Unusual Difficulty without Compensating Increase in Level of Quality or Safety
- 6. Duration of Proposed Alternative The requested duration of this relief request is until the first required re-inspection as specified in Code Case N-770-1 for Inspection Items B. As established in Code Case N-770-1, the next re-inspection would be required in the second inspection period following the baseline examination not to exceed 7 years. ASME Section XI, IWA paragraph 2430(e) provides that for plants that are out of service continuously for 6 months or more, the inspection interval during which the outage occurred may be extended for a period equivalent to the outage and the pattern of successive intervals extended accordingly. Since both SONGS Units 2 and 3 have been in outages that exceed 6-months, the requested duration may be extended in accordance with this Code provision.
- 7. References
- 1. ASME Section XI, "Rules For Inservice Inspection of Nuclear Power Plant components,"
1995 Edition with Addenda through 1996.
- 2. Nuclear Regulatory Commission Federal Register part II, Vol. 76, No. 119, effective date August 22, 2011, 10 CFR part 50 Industry Codes and Standards; Amended Requirements; Final Rule.
- 3. ASME Section Xl, Division 1, Code Case N-460, "Alternative Examination Coverage or Class 1 and Class 2 Welds, Section Xl, Division 1."
- 4. Material Reliability Program: Primary System Piping Butt Weld Inspection and evaluation Guideline (MRP-139, Revision 1), EPRI, Palo Alto, CA: 2008. 1015009.
- 5. Material Reliability Program, Alloy 82/182 Pipe Butt Weld Safety Assessment for US PWR Plant Designs (MRP-109): Westinghouse and CE Design Plants, EPRI, Palo Alto, CA: 2005. 1009804.
- 6. "Changing Frequency of Inspections for PWSCC Susceptible Welds at Cold Leg Temperatures", in Proceedings of 2011 ASME Pressure Vessels and Piping Conference, July 17-21, 2011, Baltimore, Maryland, USA.
- 7. "Technical Basis for a Flaw tolerance Option for Code Case N-770-1 for Large diameter Cold Leg Piping to Main Coolant Pump Welds, with Obstructions", in Proceedings of 2010 ASME Pressure Vessels and Piping Division Conference, July 2010, Bellevue, WA, USA.
- 8. WCAP-16423-NP, Rev. 0, "Pressurized Water Reactor Owners Group Standard Process and Methods for Calculating RCS Leak Rate for Pressurized Water Reactors,"
Westinghouse Electric Co., September 2006.
10
Enclosure 1 SONGS Units 2 and 3 Proposed Alternative in Accordance with 10 CFR 50.55a(a)(3)(ii)
Hardship or Unusual Difficulty without Compensating Increase in Level of Quality or Safety
- 9. WCAP-16465-NP, Rev. 0, "Pressurized Water Reactor Owners Group Standard RCS Leakage Action Levels and Response Guidelines for Pressurized Water Reactors,"
Westinghouse Electric Co., September 2006.
11
Enclosure 2 San Onofre Nuclear Generation Station (SONGS) Units 2 and 3 Volumetric Examination Coverage of SONGS Unit 2 & 3 Dissimilar Weld Configurations
I Enclosure 2 Volumetric Examination Coverage of SONGS Unit 2 & 3 WFow ControlCompany Dissimilar Metal Weld Configurations LMT Required Volumetric Examination Coverage of San Onofre Unit 2 & 3 Dissimilar Metal Weld Configurations
References:
o Code Case N-770-1, "Alternative Examination Requirements and Acceptance Standards for Class 1 PWR Piping and Vessel Nozzle Butt Welds Fabricated with UNS N06082 or UNS W86182 Weld Filler Material With or Without Application of Listed Mitigation Activities, Section Xl, Division 1."
FIG- 1 EXAM[NATION VOLUME IN WELDS NPS 2 (DN 50) OR LARGER Prof-le of val*,e body.
vessel nozzle, or pu**p connecti"n F --T TE C-D-E-F GhIN E RAL NJOT E: When weid end butwinrg is preset, an both sides the exaimfnatiee suiface and vokimee shalt be imastoed ifret the erd of both buaseirlrg It may indmi* remnant ailreplaced ad& and m"~ appear att~ciaiIIy deep an espesed surfaces due to fabricatioan ptwmeses gf~uteriri3 thicloses weq be dtletrayined fromi mndacsftu'r's c&'awiri or aisined ts bie ýTi. If the taro dimmmnioa is sanknotin.
1
I Enclosure 2 CUR7TISS Volumetric Examination Coverage of SONGS Unit 2 & 3 Flow Control Company Dissimilar Metal Weld Configurations L.MT References continued:
o 10 CFR 50.55a(g)(6)(ii)(F)(1) o Licensees of existing, operating pressurized water reactors as of July 21, 2011, shall implement the requirements of ASME Code Case N-770-1, subject to the conditions specified in paragraphs (g)(6)(ii)(F)(2) through (g)(6)(ii)(F)(1O) of this section, by the first refueling outage after August 22, 2011.
o 10 CFR 50.55a(g)(6)(ii)(F)(3) o Baseline examinations for welds in Table 1, Inspection Items A-1, A-2, and B, shall be completed by the end of the next refueling outage after January 20, 2012. Previous examinations of these welds can be credited for baseline examinations if they were performed within the re-inspection period for the weld item in Table 1 using Section Xl, Appendix VIII requirements and met the Code required examination volume of essentially 100 percent. Other previous examinations that do not meet these requirements can be used to meet the baseline examination requirement, provided NRC approval of alternative inspection requirements in accordance with paragraphs (a)(3)(i) or (a)(3)(ii) of this section is granted prior to the end of the next refueling outage after January 20, 2012.
> Scope:
o San Onofre 2 & 3 currently has three (3) configurations whereas essentially 100% examination coverage is not achievable per the conditions set forth by final rulemaking as it regards to Code Case N-770-1.
Configuration Inspection Examination Requirement/ Figure NO. N-770-1 (conditionedby 10CFR50.55a) PWSCC Susceptible Material Item # Required Examination Coverage Achievable Examination Coverage Achievable RCP Suction B Figure 1 61.5% 55.2%
RCP Discharge B Figure 1 A : 45.2% B : 50.5% C : 50.5% D : 55.8% A: 38.7% B : 44.0% C : 44.0% D : 49.3%
Cold Leg ECCS B Figure 1 60.9% 64.7%
2
I Enclosure 2 CURT1S$ Volumetric Examination Coverage of SONGS Unit 2 & 3 FlwWRIGHT" Control Company LMT Dissimilar Metal Weld Configurations Reactor Coolant Pump (RCP) SUCTION PHOTOGRAPH TYPICAL - ALL CONFIGURATIONS 3
I Enclosure 2 CUTIMSS Volumetric Examination Coverage of SONGS Unit 2 & 3 LMT Dissimilar Metal Weld Configurations RCP SUCTION N-770-1 REQUIRED COVERAGE [ 2.73 in2 ]
C-D-E-F TYPICAL OF ALL RCP SUCTION WELD CONFIGURATIONS Inservice Inspection (ISI) Weld Identification Associated RCP POOl P002 P003 P004 SONGS-2 02-008-002 02-014-002 02-010-002 02-012-002 SONGS-3 03-010-002 03-012-002 03-008-002 03-014-002 Alloy 182 Weld A
C D 2.73 sq in SA-516 Gr. 70 Elbow SA-351 Gr. CF8M CASS Safe End
- F E 4
I Enclosure 2 MWRIGHT Volumetric Examination Coverage of SONGS Unit 2 & 3
. Flow Control Company LMT Dissimilar Metal Weld Configurations RCP SUCTION COVERAGE CALCULATIONS
{Axial Scan Direction}
Uloy 182 Weld C, ,D 2.73 sq in achieved 45/60 SA-516 Gr. 70 Elbow SA r. CF8M CASS Safe End 5
I Enclosure 2 CURIr7SS WRIGHT Volumetric Examination Coverage of SONGS Unit 2 & 3 Flw Control Company LMT Dissimilar Metal Weld Configurations RCP SUCTION COVERAGE CALCULATIONS
{Circumferential Scan Direction)
Alloy 182 Weld A
0.63 sq in achicved 45 C -D ,1+
SA-516 Gr. 70 Elbow SA-351 Gr. CF8M CASS Safe End 6
I Enclosure 2 CURMS$
Volumetric Examination Coverage of SONGS Unit 2 & 3 Control Company Dissimilar Metal Weld Configurations LMT RCP SUCTION COVERAGE CALCULATIONS TYPICAL - ALL CONFIGURATIONS Coverage calculations are based on American Society of Mechanical Engineers (ASME) Code Case N-770-1, Table-1 required examination volume {C-D-E-F}. All dimensions are derived from actual field measurements of the referenced configuration(s) and appropriate ultrasonic beam path(s) utilized for examination(s).
X = PERCENTAGE OF REQUIRED EXAMINATION COVERAGE ACHIEVED 2
R = N-770-1 REQUIRED EXAMINATION CROSS-SECTIONAL AREA (2.73 in ) 2 A = ACHIEVED EXAMINATION CROSS-SECTIONAL COVERAGE IN THE AXIAL SCAN DIRECTION (2.73 in )
AC = CIRCUMFERENTIAL LENGTH OF UNOBSTRUCTED COVERAGE IN THE AXIAL SCAN DIRECTION (115 in) 2 C = ACHIEVED EXAMINATION CROSS-SECTIONAL COVERAGE IN THE CIRCUMFERENTIAL SCAN DIRECTION (0.63 in )
CC = CIRCUMFERENTIAL LENGTH OF UNOBSTRUCTED COVERAGE IN THE CIRCUMFERENTIAL SCAN DIRECTION (115 in)
WC = TOTAL WELD CIRCUMFERENCE (115 in) in)
(2.73 nzn)(11S in) +(0.63 in 2)(115 SX=
2(2.73 in 2 ) X (115 in) 3 in 386.4 627.9 in3 7
I Enclosure 2 CURTiSS Volumetric Examination Coverage of SONGS Unit 2 & 3 MWRIGHT
'_))Flow Control Companyr LMT Dissimilar Metal Weld Configurations
- X = 0.615 (61.5%)
RCP SUCTION PRIMARY WATER STRESS CORROSION CRACKING (PWSCC) SUSCEPTIBLE MATERIAL ONLY [1.54 in2 ]
C-D-E-F Alloy 182 Weld C D 1.54 sqin SA-516 Gr. 70 Elbow A>1 SA-351 Gr. CF8M CASS Safe End F
8
I Enclosure 2 CURTISS Volumetric Examination Coverage of SONGS Unit 2 & 3 WRIGHT
=6Flow ControlCompany Dissimilar Metal Weld Configurations LMT RCP SUCTION PWSCC SUSCEPTIBLE MATERIAL ONLY COVERAGE CALCULATIONS
{Axial Scan Direction}
... Alloy 182 Weld A
r 1.54 sq in achieved 45/60 SA-516 Gr. 70 Elbow
\.SA- -Gr. CF8M CASS Safe End 1.
9
I Enclosure 2 0t" W RI H Volumetric Examination Coverage of SONGS Unit 2 & 3 4tFiow ControlCompany Dissimilar Metal Weld Configurations LMT RCP SUCTION PWSCC SUSCEPTIBLE MATERIAL ONLY COVERAGE CALCULATIONS
{Circumferential Scan Direction)
Alloy 182 WvVeld C D 0.16 sq in achieved 45 SA-516 Gr. 70 Elbow I m
SA-351 Gr. CF8M CASS Safe End F
10
I Enclosure 2 CUR77SS Volumetric Examination Coverage of SONGS Unit 2 & 3
\ WRIGLMT
~~w Control Company LMT Dissimilar Metal Weld Configurations RCP SUCTION COVERAGE CALCULATIONS IN SUSCEPTABLE VOLUME ONLY TYPICAL - ALL CONFIGURATIONS
> Coverage calculations are based on the susceptible weld volume estimated from design drawings and ultrasonic beam paths utilized for examination(s).
x = (A) (AC)+(C)(CC) 2(R) (Wc)
X = PERCENTAGE OF PWSCC SUSCEPTIBLE WELD VOLUME COVERAGE ACHIEVED R = CROSS-SECTIONAL AREA OFSUSCEPTIBLE WELD VOLUME (1.54 in2) 2 A = ACHIEVED EXAMINATION CROSS-SECTIONAL COVERAGE IN THE AXIAL SCAN DIRECTION (1.54 in )
AC = CIRCUMFERENTIAL LENGTH OF UNOBSTRUCTED COVERAGE IN THE AXIAL SCAN DIRECTION (115 in)
C = ACHIEVED EXAMINATION CROSS-SECTIONAL COVERAGE IN THE CIRCUMFERENTIAL SCAN DIRECTION (0.16 in2 )
CC = CIRCUMFERENTIAL LENGTH OF UNOBSTRUCTED COVERAGE IN THE CIRCUMFERENTIAL SCAN DIRECTION ( 115 in)
WC = TOTAL WELD CIRCUMFERENCE(115 in) 2 X=- (1.S4 inZ)(IIS in) +(0.16 in )(11S in) 2(1.54 in 2 ) x (115 in) 3 in 195.5 354.2 in2 SX = 0.552 (55.2%)
11
I Enclosure 2 6URTNSS t*WRIGHT Flow ControlCompany Volumetric Examination Coverage of SONGS Unit 2 & 3 Dissimilar Metal Weld Configurations LMT RCP DISCHARGE PHOTOGRAPH NOTE RESISTANCE TEMPERATURE DETECTOR (RTD) OBSTRUCTION OF AXIAL SCANS (CONFIGURATION B&C) 12
I Enclosure 2 CUR7TIS5 Volumetric Examination Coverage of SONGS Unit 2 & 3 afiFow WRIGHTL Control Company LMT Dissimilar Metal Weld Configurations CONFIGURATION "A" SHOWING OBSTRUCTIONS TO AXIAL SCAN OF RCP DISCHARGE NET AXIAL SCAN OBSTRUCTION IS 34.1 INCHES OF THE TOTAL 115 INCH PIPE CIRCUMFERENCE Associated RCP Pool SONGS-2 02-009-002 SONGS-3 03-011-002 12.1 12.1 in in 13
I Enclosure 2 CUR T7SS Volumetric Examination Coverage of SONGS Unit 2 & 3 w Control Company Dissimilar Metal Weld Configurations LMTI CONFIGURATION "B" AND "C" SHOWING OBSTRUCTIONS TO AXIAL SCAN OF RCP DISCHARGE NET AXIAL SCAN OBSTRUCTION IS 22.0 INCHES OF THE TOTAL 115 INCH PIPE CIRCUMFERENCE Associated RCP P003 P004 SONGS-2 02-011-002 02-013-002 SONGS-3 03-009-002 03-015-002 3.3 in SPRAYCHARING INLEI7 SpPRAYI 12.1in 12.1 14
I Enclosure 2 CU~rrTSS LWRIGHT Volumetric Examination Coverage of SONGS Unit 2 & 3 Fow Control Company LMT Dissimilar Metal Weld Configurations CONFIGURATION "D" SHOWING OBSTRUCTIONS TO AXIAL SCAN OF RCP DISCHARGE NET AXIAL SCAN OBSTRUCTION IS 9.9 INCHES OF THE TOTAL 115 INCH PIPE CIRCUMFERENCE RCP Location P002 SONGS-2 02-015-002 SONGS-3 03-013-002 333 in RTDI) 15
I Enclosure 2 CUATWS$
Volumetric Examination Coverage of SONGS Unit 2 & 3 Flow Control Company Dissimilar Metal Weld Configurations LMT RCP DISCHARGE N-770-1 REQUIRED COVERAGE [2.52 in2]
C-D-E-F TYPICAL - ALL CONFIGURATIONS I' Alloy 182 Weld C
inD
......2.52 sq SA- 516 Gr. 70 Pipe SA-351 Gr. CF8M CASS Safe End
.. .F...
16
I Enclosure 2 CUMn7SS Volumetric Examination Coverage of SONGS Unit 2 & 3 SFlow Control Company Dissimilar Metal Weld Configurations LMT RCP DISCHARGE COVERAGE CALCULATIONS
{Axial Scan Direction}
Alloy 182 Weld A
C D 2.52 sq in achicved 45/60 SA-516 Gr. 70 Pipe
-SA- r. CF8M CASS Safe End F
17
I Enclosure 2 CURTISS Volumetric Examination Coverage of SONGS Unit 2 & 3 Flw Control Company LWRIGHT Dissimilar Metal Weld Configurations LMT RCP DISCHARGE COVERAGE CALCULATIONS
{Circumferential Scan Direction}
Alloy 182 Weld A
C 0.51 sq in achieved 45 SA-516 Gr. 70 Pipe SA-351 Gr. CF8M CASS Safe End
- F E 18
I Enclosure 2 CURT7SS LWRIGHT Volumetric Examination Coverage of SONGS Unit 2 & 3
- ) Flow Control Companyr LMT Dissimilar Metal Weld Configurations RCP DISCHARGE COVERAGE CALCULATIONS CONFIGURATION 'A' Coverage calculations are based on ASME Code Case N-770-1, Table I required examination volume {C-D-E-F}. All dimensions are derived from actual field measurements of the referenced configuration(s) and appropriate ultrasonic beam path(s) utilized for examination(s).
X = PERCENTAGE OF REQUIRED EXAMINATION COVERAGE ACHIEVED R = N-770-1 REQUIRED EXAMINATION CROSS-SECTIONAL AREA (2.52 in2) 2 A = ACHIEVED EXAMINATION CROSS-SECTIONAL COVERAGE IN THE AXIAL SCAN DIRECTION (2.52 in )
AC = CIRCUMFERENTIAL LENGTH OF UNOBSTRUCTED COVERAGE IN THE AXIAL SCAN DIRECTION (80.9 in) 2 C = ACHIEVED EXAMINATION CROSS-SECTIONAL COVERAGE IN THE CIRCUMFERENTIAL SCAN DIRECTION (0.51 in )
CC = CIRCUMFERENTIAL LENGTH OF UNOBSTRUCTED COVERAGE IN THE CIRCUMFERENTIAL SCAN DIRECTION (115 in)
WC = TOTAL WELD CIRCUMFERENCE (115 in)
Sx - (2.52 in2})(9.9 im)+
2 2
(o.5 1 in )(,15 2(2.S2 i-n ) X (1 IS in) in) x = 262.5 ina 579.6 in3
- X = 0.452 (45.2%)
19
I Enclosure 2 CURTiSS MWRIGHT Volumetric Examination Coverage of SONGS Unit 2 & 3
- ._)Flow Control Company LMT Dissimilar Metal Weld Configurations RCP DISCHARGE COVERAGE CALCULATIONS CONFIGURATION 'B' & 'C' Coverage calculations are based on ASME Code Case N-770-1, Table 1 required examination volume {C-D-E-F}. All dimensions are derived from actual field measurements of the referenced configuration(s) and appropriate ultrasonic beam path(s) utilized for examination(s).
X = PERCENTAGE OF REQUIRED EXAMINATION COVERAGE ACHIEVED R = N-770-1 REQUIRED EXAMINATION CROSS-SECTIONAL AREA (2.52 in 2)
(2.52 in2)
A = ACHIEVED EXAMINATION CROSS-SECTIONAL COVERAGE IN THE AXIAL SCAN DIRECTION AC = CIRCUMFERENTIAL LENGTH OF UNOBSTRUCTED COVERAGE IN THE AXIAL SCAN DIRECTION (93.0 in) 2 C = ACHIEVED EXAMINATION CROSS-SECTIONAL COVERAGE IN THE CIRCUMFERENTIAL SCAN DIRECTION (0.51 in )
CC= CIRCUMFERENTIAL LENGTH OF UNOBSTRUCTED COVERAGE IN THE CIRCUMFERENTIAL SCAN DIRECTION (115 in)
WC = TOTAL WELD CIRCUMFERENCE (115 in)
- X=[2.52 in7)( 93 .0 in) + o(.5 Ii, 2
2(2.52 in ) x (115 in) 2 1(115 in) 2 293.0 in 1
579.6 in SX = 0.505 (50.5 %)
20
I Enclosure 2 Volumetric Examination Coverage of SONGS Unit 2 & 3
\ Fiow ControlCompany Dissimilar Metal Weld Configurations LMT RCP DISCHARGE COVERAGE CALCULATIONS CONFIGURATION 'D' Coverage calculations are based on ASME Code Case N-770-1, Table 1 required examination volume {C-D-E-F}. All dimensions are derived from actual field measurements of the referenced configuration(s) and appropriate ultrasonic beam path(s) utilized for examination(s).
X -- (A)(AC)+(C)(CC) 2 (R) (W0 X = PERCENTAGE OF REQUIRED EXAMINATION COVERAGE ACHIEVED R = N-770-1 REQUIRED EXAMINATION CROSSECTIONAL AREA (2.52 in2)
A = ACHIEVED EXAMINATION CROSS-SECTIONAL COVERAGE IN THE AXIAL SCAN DIRECTION (2.52 in 2)
AC = CIRCUMFERENTIAL LENGTH OF UNOBSTRUCTED COVERAGE IN THE AXIAL SCAN DIRECTION (105.1 in)
C = ACHIEVED EXAMINATION CROSS-SECTIONAL COVERAGE IN THE CIRCUMFERENTIAL SCAN DIRECTION (0.51 in 2)
CC = CIRCUMFERENTIAL LENGTH OF UNOBSTRUCTED COVERAGE IN THE CIRCUMFERENTIAL SCAN DIRECTION (115 in)
WC = TOTAL WELD CIRCUMFERENCE (115 in) 1(115 in)
- x - [2.52 in;)(1OS.1 in)2 (0.51 inZ 2(2.52 i ))x (115 in)
Sx= 323.5 in2 579.6 ina X
X = 0.5 58 (55.8 %)
21
I Enclosure 2 CUR7lSS "L WRIGHT Volumetric Examination Coverage of SONGS Unit 2 & 3
- )FIow Control Company LMT Dissimilar Metal Weld Configurations RCP DISCHARGE PWSCC SUSCEPTIBLE MATERIAL ONLY [1.4 in2]
C-D-E-F Alloy 182 Weld C D
+4ý 21.4 sq in SA-516 Gr. 70 Pipe SA-351 Gr. CF8M CASS Safe End E
22
Enclosure 2 6URTISS I Volumetric Examination Coverage of SONGS Unit 2 & 3
- .)Flow Control Company~
LWRIGHT Dissimilar Metal Weld Configurations LMT RCP DISCHARGE PWSCC SUSCEPTIBLE MATERIAL ONLY COVERAGE CALCULATIONS
{Axial Scan Direction}
Alloy 182 Weld A
C D 1.4 sq in achieved 45/60 SA 516 Gr. 70 Pipe 8M CASS Safe End E S-A--351 Gr. Cf r
23
I Enclosure 2 CURTiSS LWRIGHT Volumetric Examination Coverage of SONGS Unit 2 & 3 Fow Control Companyr LMT Dissimilar Metal Weld Configurations RCP DISCHARGE PWSCC SUSCEPTIBLE MATERIAL ONLY COVERAGE CALCULATIONS
{Circumferential Scan Direction}
Alloy 182 Weld
'low D
0.11 sq in achieved 45 SA-516 Gr. 70 Pipe m
SA-351 Gr. CF8M CASS Safe End F
24
I Enclosure 2 CUR TYSS Volumetric Examination Coverage of SONGS Unit 2 & 3 MWRIGHT
- .)iFlow Control Company LMT Dissimilar Metal Weld Configurations RCP DISCHARGE COVERAGE CALCULATIONS IN SUSCEPTABLE VOLUME ONLY CONFIGURATION 'A' Coverage calculations are based on the susceptible weld volume estimated from design drawings and ultrasonic beam paths utilized for examination(s).
>X = (A)(AC)+(C)(CC) 2(R) (WC)
X = PERCENTAGE OF PWSCCSUSCEPTIBLE WELD VOLUME COVERAGE ACHIEVED R = CROSS-SECTIONAL AREA OF SUSCEPTIBLE WELD VOLUME (1.4 in2)
A = ACHIEVED EXAMINATION CROSS-SECTIONAL COVERAGE IN THE AXIAL SCAN DIRECTION (1.4 in2)
AC = CIRCUMFERENTIAL LENGTH OF UNOBSTRUCTED COVERAGE IN THE AXIAL SCAN DIRECTION (80.9 in)
C = ACHIEVED EXAMINATION CROSS-SECTIONAL COVERAGE IN THE CIRCUMFERENTIAL SCAN DIRECTION (0.1 in2)
CC = CIRCUMFERENTIAL LENGTH OF UNOBSTRUCTED COVERAGE IN THE CIRCUMFERENTIAL SCAN DIRECTION (115 in)
WC = TOTAL WELD CIRCUMFERENCE (115 in) 2 in 2 )(80.9 inn) +(O.1 in S(1.4 }(115 in) 2 2(1.4 in ) x (1 S in).
in3
~124.8 ina X-322
- X = 0.387 (38.7%)
25
I Enclosure 2 CURT7SS Volumetric Examination Coverage of SONGS Unit 2 & 3
~4 WRIGHT L lw Control Company LMT Dissimilar Metal Weld Configurations RCP DISCHARGE COVERAGE CALCULATIONS IN SUSCEPTABLE VOLUME ONLY CONFIGURATION 'B' & 'C'
> Coverage calculations are based on the susceptible weld volume estimated from design drawings and ultrasonic beam paths utilized for examination(s).
> X (A) (AC)+(C)(CC) 2(R) (WC)
X = PERCENTAGE OF PWSCC SUSCEPTIBLE WELD VOLUME COVERAGE ACHIEVED R = CROSS-SECTIONAL AREA OF SUSCEPTIBLE WELD VOLUME (1.4 in2)
A = ACHIEVED EXAMINATION CROSS-SECTIONAL COVERAGE IN THE AXIAL SCAN DIRECTION (1.4 in2)
AC = CIRCUMFERENTIAL LENGTH OF UNOBSTRUCTED COVERAGE IN THE AXIAL SCAN DIRECTION (93.0 in)
C = ACHIEVED EXAMINATION CROSS-SECTIONAL COVERAGE IN THE CIRCUMFERENTIAL SCAN DIRECTION (0.1 in2)
CC= CIRCUMFERENTIAL LENGTH OF UNOBSTRUCTED COVERAGE IN THE CIRCUMFERENTIAL SCAN DIRECTION (115 in)
WC = TOTAL WELD CIRCUMFERENCE (115 in) in 2 )(93.o in) +(o.1 in 2 }(11s in)
S(1.4 2(1.4 in 2 )x (115 in) 3 Mn 141.7 322.0 MnR SX = 0.440 (44.0 %)
26
I Enclosure 2 CURTISS Volumetric Examination Coverage of SONGS Unit 2 & 3 C)"VWRIGHT Flow ControlCompany Dissimilar Metal Weld Configurations LMT RCP DISCHARGE COVERAGE CALCULATIONS IN SUSCEPTABLE VOLUME ONLY CONFIGURATION 'D' Coverage calculations are based on the susceptible weld volume estimated from design drawings and ultrasonic beam paths utilized for examination(s).
X = PERCENTAGE OF PWSCCSUSCEPTIBLE WELD VOLUME COVERAGE ACHIEVED R = CROSS-SECTIONAL AREA OF SUSCEPTIBLE WELD VOLUME (1.4 in 2)
A = ACHIEVED EXAMINATION CROSS-SECTIONAL COVERAGE IN THE AXIAL SCAN DIRECTION (1.4 in2)
AC = CIRCUMFERENTIAL LENGTH OF UNOBSTRUCTED COVERAGE IN THE AXIAL SCAN DIRECTION (105.1 in)
C = ACHIEVED EXAMINATION CROSS-SECTIONAL COVERAGE IN THE CIRCUMFERENTIAL SCAN DIRECTION (0.1 in2)
CC = CIRCUMFERENTIAL LENGTH OF UNOBSTRUCTED COVERAGE IN THE CIRCUMFERENTIAL SCAN DIRECTION (115 in)
WC = TOTAL WELD CIRCUMFERENCE (115 in)
=1.4 in 2 )(1O5.1 fn)+(o.1 ,n 2 )(115 in) 2(1.4 itn 2 )r (115 in) 3 in 158.6 322.0 in3 XX= 0.493 (49.3%)
27
I Enclosure 2 CUR Tls$
t*WR/GHT Volumetric Examination Coverage of SONGS Unit 2 & 3
)FIow ControlCompany Dissimilar Metal Weld Configurations LMT COLD LEG EMERGENCY CORE COOLING SYSTEM (ECCS) INJECTION NOZZLE PHOTOGRAPH TYPICAL - ALL CONFIGURATIONS 28
I Enclosure 2 CURTI7S Volumetric Examination Coverage of SONGS Unit 2 & 3 LWRIGHT
- .;Flow Control Companyr LMT Dissimilar Metal Weld Configurations COLD LEG ECCS INJECTION NOZZLE N-770-1 REQUIRED COVERAGE [1.28 in2]
C-D-E-F TYPICAL - ALL CONFIGURATIONS ISI Weld Identification Associated RCP POOl P002 P003 P004 SONGS-2 02-009-012 02-015-010 02-011-011 02-013-011 SONGS-3 03-011-011 03-013-011 03-009-012 03-015-010 Alloy 182 Weld C A 351 Gr. CF8M CASS Safe End SAN508 C:1. 2 Noz'lc I sq in F
TE 29
I Enclosure 2 OiWRIGHT Volumetric Examination Coverage of SONGS Unit 2 & 3 Flw Control Company Dissimilar Metal Weld Configurations LMT COLD LEG ECCS INJECTION NOZZLE COVERAGE CALCULATIONS
{Axial Scan Direction)
(Combined 450/600 Coverage - 1.15 in2)
Alloy 182 Weld SA-351 Gr. CF8M CASS Safe End SA-508 Cl. 2 Nozzle \\C D 1-.02 sq in achicvcdl 45 E
Alloy 182 Weld SA-351 Gr. CF8M CASS Safe End SA-508 C1.*2-INoz._
0=A C .
D 1.28 sq in achic'ed 60 F
E 30
I Enclosure 2 CUR "155 Volumetric Examination Coverage of SONGS Unit 2 & 3 f* *)Flow WRIGHT Control Company Dissimilar Metal Weld Configurations LMT COLD LEG ECCS INJECTION NOZZLE COVERAGE CALCULATIONS
{Axial Scan Direction)
Alloy 182 Weld SA-508 Cl. 2 Nozzle 0.43 sq in achieved 45 C /SA-351 ýD Gr. CF8M CASS Safe End F
31
I Enclosure 2 CURTISS Volumetric Examination Coverage of SONGS Unit 2 & 3 LWRIGHT
\.))Flow Control Company LMT Dissimilar Metal Weld Configurations COLD LEG ECCS INJECTION NOZZLE COVERAGE CALCULATIONS TYPICAL- ALL CONFIGURATIONS
> Coverage calculations are based on ASME Code Case N-770-1, Table-1 required examination volume {C-D-E-F}. All dimensions are derived from actual field measurements of the referenced configuration(s) and appropriate ultrasonic beam path(s) utilized for examination(s).
>x = (A)(AC)+(C)(C 2(R) (Wo X = PERCENTAGE OF REQUIRED EXAMINATION COVERAGE ACHIEVED R = N-770-1 REQUIRED EXAMINATION CROSS-SECTIONAL AREA (1.28 in2) 2 A = ACHIEVED EXAMINATION CROSS-SECTIONAL COVERAGE IN THE AXIAL SG4N DIRECTION (1.15 in )
AC = CIRCUMFERENTIAL LENGTH OF UNOBSTRUCTED COVERAGE IN THE AXIAL SCAN DIRECTION (41 in) 2 C= ACHIEVED EXAMINATION CROSS-SECTIONAL COVERAGE IN THE CIRCUMFERENTIAL SCAN DIRECTION ( 0.43 in )
CC = CIRCUMFERENTIAL LENGTH OF UNOBSTRUCTED COVERAGE IN THE CIRCUMFERENTIAL SCAN DIRECTION (41 in)
WC = TOTAL WELD CIRCUMFERENCE(41 in)
[1.15 inz)(41 in) +(0.41 inz )(41 in) 2(1.29 inz)x (41 in) ins 63.96 104.96 im2
- X = 0.609 (60.9%)
32
I Enclosure 2 CUJTIS$ Volumetric Examination Coverage of SONGS Unit 2 & 3
- i Flow Control Company LMT Dissimilar Metal Weld Configurations COLD LEG ECCS INJECTION NOZZLE PWSCC SUSCEPTIBLE MATERIAL ONLY [0.75 in 2]
C-D-E-F TYPICAL - ALL CONFIGURATIONS Alloy 182 Weld SA-351 Gr. CF8M CASS Safe End SA-508 Cl. 2 Nozzle C
33
I Enclosure 2 CURTISS Volumetric Examination Coverage of SONGS Unit 2 & 3 OWRIGHT Flow ControlCompany Dissimilar Metal Weld Configurations LMT COLD LEG ECCS INJECTION NOZZLE PWSCC SUSCEPTIBLE MATERIAL ONLY COVERAGE CALCULATIONS
{Axial Scan Direction)
Alloy 182 Weld SA-351 Gr. CF8M CASS Safe End SA- 508 C 1.2 N\C" SA-08 No -. \\ I1n 0.75 sq in achieved 45 / 60
",\ NN\
1 34
I Enclosure 2 Cur Volumetric Examination Coverage of SONGS Unit 2 & 3
) MIow ControlCompany Dissimilar Metal Weld Configurations LMT COLD LEG ECCS INJECTION NOZZLE PWSCC SUSCEPTIBLE MATERIAL ONLY COVERAGE CALCULATIONS
{Circumferential Scan Direction}
Alloy 182 Weld SA- 508 Cl. 2 Nozle SA-351 Gr. CF8M CASS Safe End 0.22 sq in achievcd 45 C,-4 t
35
I Enclosure 2 CUR7TISS Volumetric Examination Coverage of SONGS Unit 2 & 3 MWRIGHT
\*)Flow Control Company LMT Dissimilar Metal Weld Configurations COLD LEG ECCS INJECTION NOZZLE COVERAGE CALCULATIONS TYPICAL - ALL CONFIGURATIONS Coverage calculations are based on the susceptible weld volume estimated from design drawings and ultrasonic beam paths utilized for examination(s).
X -- (A)(AC)+(C)(CC) 2(R) (WC)
X = PERCENTAGE OF PWSCC SUSCEPTIBLE WELD VOLUME COVERAGE ACHIEVED R = CROSS-SECTIONAL AREA OF SUSCEPTIBLE WELD VOLUME (0. 75 in2)
A = ACHIEVED EXAMINATION CROSS-SECTIONAL COVERAGE IN THE AXIAL SCAN DIRECTION (0.75 in2)
AC = CIRCUMFERENTIAL LENGTH OF UNOBSTRUCTED COVERAGE IN THE AXIAL SCAN DIRECTION (41 in)
C = ACHIEVED EXAMINATION CROSS-SECTIONAL COVERAGE IN THE CIRCUMFERENTIAL SCAN DIRECTION (0.22 in2)
CC = CIRCUMFERENTIAL LENGTH OF UNOBSTRUCTED COVERAGE IN THE CIRCUMFERENTIAL SCAN DIRECTION (41 in)
WC = TOTAL WELD CIRCUMFERENCE(41 in)
S0.75 in2)(41 in)+(0.22 an2 )(41 in) 2(0.75 in2 ) x (41 in) 2 39.77 in 61.5 in2
- X = 0.647 (64.7%)
36