SVPLTR 04-0024, Relief Request CR-26, Inservice Inspection Program Relief Regarding Examination Coverage for Third 1 0-Year Inservice Inspection Interval
| ML041320487 | |
| Person / Time | |
|---|---|
| Site: | Dresden  |
| Issue date: | 05/04/2004 |
| From: | Bost D Exelon Generation Co, Exelon Nuclear |
| To: | Document Control Desk, Office of Nuclear Reactor Regulation |
| References | |
| SVPLTR: #04-0024 | |
| Download: ML041320487 (10) | |
Text
o IExelon Exelon Generation Company, LLC Dresden Nuclear Power Station www.exeloncorp.com Nuclear 6500 North Dresden Road Morris, IL 60450-9765 10 CFR 50.55a May 4, 2004 SVPLTR: #04-0024 U. S. Nuclear Regulatory Commission ATTN: Document Control Desk Washington, D.C. 20555-0001 Dresden Nuclear Power Station, Units 2 and 3 Facility Operating License Nos. DPR-1 9 and DPR-25 NRC Docket Nos. 50-237 and 50-249
Subject:
Relief Request CR-26, Inservice Inspection Program Relief Regarding Examination Coverage for Third 10-Year Inservice Inspection Interval
Reference:
- 1) Letter from L. W. Rossbach (U. S. NRC) to 0. D. Kingsley (Exelon Generation Company, LLC), "Exemption from the Requirements of 10 CFR 50.55a(g)(6)(ii)(A)(2), Inservice Examination of the Reactor Pressure Vessel,"
dated September 28, 2001
- 2) Letter from A. J. Mendiola (U. S. NRC) to J. L. Skolds (Exelon Generation Company, LLC), "Relief Request CR-25 for Third 10-Year Inservice Inspection Interval," dated July 1, 2003 In accordance with 10 CFR 50.55a, "Codes and Standards," paragraph (g)(5)(iii), Dresden Nuclear Power Station (DNPS) is requesting relief from American Society of Mechanical Engineers (ASME) Boiler and Pressure Vessel Code, Section Xl, "Rules for Inservice Inspection of Nuclear Power Plant Components," on the basis that compliance with the specified requirements is impractical due to plant design. DNPS is submitting this relief request for those ASME Section Xl weld examinations performed during the Third 10-Year Inservice Inspection Interval where the inspection coverage achieved was less than or equal to 90%. Specifically, this includes examinations completed during the third period of the Third 10-Year Inservice Inspection Interval for both Units 2 and 3.
The proposed relief request is for the third period of the Third 10-Year Inservice Inspection Interval for both Units 2 and 3. For Unit 2, the Third 10-Year Inservice Inspection Interval began on March 1, 1992, and ended on September 30, 2003. All scheduled Unit 2 ASME Section Xl examinations were completed prior to September 30, 2003, with the exception of Examination Category B-A reactor vessel shell welds and Examination Category B-O control rod drive housing welds. Approval to delay both groups of welds was provided by the NRC in References 1 and 2 respectively. Examination Category B-A and B-O examinations were completed during the Unit 2 refueling outage, which began on October 14, 2003, and was completed on 1)ICqL
May 4, 2004 U.S. Nuclear Regulatory Commission Page 2 November 11, 2003. A relief for the Examination Category B-A longitudinal reactor vessel shell welds is being submitted under separate cover.
For Unit 3, the Third 10-Year Inservice Inspection Interval began on March 1,1992, and ended on October 31, 2003. All scheduled Unit 3 ASME Section Xl examinations were completed prior to October 31, 2003, with the exception of Examination Category B-A reactor vessel shell welds.
Approval to delay examinations was provided by the NRC in Reference 1. The remaining Examination Category B-A longitudinal reactor weld shell welds are scheduled to be completed during the upcoming Unit 3 refueling outage currently scheduled to begin on October 26, 2004, and a separate relief request will be submitted.
Should you have any questions concerning his letter, please contact Mr. Jeff Hansen at (815) 416-2800.
Respectfully, Danny 4 Site Vice President Dresden Nuclear Power Station
Attachment:
10 CFR 50.55a Request Number CR-26 cc: Regional Administrator - NRC Region IlIl NRC Senior Resident Inspector - Dresden Nuclear Power Station
ATTACHMENT 10 CFR 50.55a Request Number CR-26 Relief Requested In Accordance with 10 CFR 50.55a(g)(5)(iii)
Page 1 of 8 ASME Code Components Affected Components affected are American Society of Mechanical Engineers (ASME) Boiler and Pressure Vessel Code (Code), Section Xl, Class 1 and 2 components specified in Table CR-26.1 and CR-26.2.
Applicable Code Edition and Addenda
The applicable ASME Code, Section Xl, for Dresden Nuclear Power Station (DNPS), Units 2 and 3 Third 10-Year Inservice Inspection Interval is the 1989 Edition.
Applicable Code Requirement
Subarticle IWB-2500 states in part "Components shall be examined and tested as specified in Table IWB-2500-1." Table IWB-2500-1 requires a volumetric examination or a surface and volumetric examination be performed on the component based on Category and Item Number.
The applicable examination area or volume and method required is as shown below from Table IWB-2500-1:
Examination Item Examination Requirements/ Examination Method Category Number Figure Number B-A B1.30 IWB-2500-4 Volumetric B-D B3.90 IWB-2500-7(a) Volumetric IWB-2500-7(b)
B-D B3.100 IWB-2500-7(a) Volumetric IWB-2500-7(b)
B-M-1 IB12.40 IWB-2500-17 Volumetric Subarticle IWC-2500 states in part "Components shall be examined and pressure tested as specified in Table IWC-2500-1." Table IWC-2500-1 requires a surface examination or a surface and volumetric examination be performed on the component based on Category and Item Number. The applicable examination area or volume and method required is as shown below from Table IWC-2500-1:
Examination Item Examination Requirements Examination Method Category Number /Figure Number C-B C2.21 IWC-2500-4(b) Surface & Volumetric C-C C3.20 IWC-2500-5(a) Surface I _ _ _I_ _ I_ IWC-2500-5(b) II Entire volume or area required is defined by ASME Section Xl Code Case N-460, "Alternative Examination Coverage for Class 1 and Class 2 Welds,Section XI, Division 1." Code Case N-460 states in part, "...when the entire examination volume or area cannot be examined...a reduction in examination coverage.. .may be accepted provided the reduction in coverage for Revision 0
ATTACHMENT 10 CFR 50.55a Request Number CR-26 Relief Requested In Accordance with 10 CFR 50.55a(g)(5)(iii)
Page 2 of 8 that weld is less than 10%." DNPS invokes Code Case N-460 for use during the Third 10-Year Inservice Inspection Interval.
NRC Information Notice 98-42, "Implementation of 10 CFR 50.55a(g) Inservice Inspection Requirements," termed the reduction in coverage of less than 10% to be "essentially 100 percent." Information Notice 98-42 states in part, "The NRC has adopted and further refined the definition of "essentially 100 percent" to mean "greater than 90 percent"...has been applied to all examinations of welds or other areas required by ASME Section Xl."
Impracticality of Compliance DNPS, Units 2 and 3, obtained Construction Permits CPPR-18 and CPPR-22 on January 10, 1966 and October 14, 1966, respectively. The piping systems and associated components were designed and fabricated before the examination requirements of ASME Section Xl were formalized and published. Since this plant was not specifically designed to meet the requirements of ASME Section Xl, full compliance is not feasible or practical within the limits of the current plant design.
Physical obstructions imposed by design, geometry and materials of construction are typical of vessel appurtenances and sacrificial shield, insulation support rings, structural and component support members, adjacent component weldments in close proximity, unique component configurations and dissimilar metal weldments.
Burden Caused by Compliance Compliance with the examination requirements of ASME Section XI would require modification of plant components to remove obstructions, redesigning of plant systems, and replace components where geometry is inherent to component design.
Proposed Alternative and Basis for Use Proposed Alternative In accordance with 10 CFR 50.55a(g)(5)(iii), relief is requested on the basis that the required "essentially 100%" coverage examination is impractical due to physical obstructions and limitations imposed by design, geometry and materials of construction for the components of Table CR-26.1 and Table CR-26.2.
DNPS will continue to perform best effort examinations in order to achieve the maximum amount of coverage. Additionally, a VT-2 examination performed on the subject components during system pressure test per examination category B-P each refueling outage and category C-H each inspection period is performed.
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ATTACHMENT 10 CFR 50.55a Request Number CR-26 Relief Requested In Accordance with 10 CFR 50.55a(g)(5)(iii)
Page 3 of 8 Basis For Use Improved examination techniques have been progressively upgraded during this interval to augment the required Section Xi examinations. EGC has used the Electric Power Research Institute (EPRI), the Performance Demonstration Initiative (PDI), Inservice Inspection vendors and other industry sources to encourage the development of and provide an awareness of improved examination techniques to enhance coverage and flaw detection commensurate with radiation dose reduction.
EGC examination procedures are revised on a continuing basis to incorporate proven techniques for a higher level of safety and quality as they become available. The examinations and techniques used today exceed the examinations conducted in the past on each component.
All components received as a minimum, the required examination(s) applicable to the extent practical due to the limited or lack of access available. The examinations conducted, confirmed satisfactory results evidencing no unacceptable flaws present, even though "essentially 100%"
coverage was not attained. EGC has concluded that if any active degradation mechanisms were to exist in the subject welds, those degradations would have been identified in the examinations performed.
Based on the above, with our earlier design, the underlying objectives of the code required volumetric and surface examinations have been met. The examinations were completed to the extent practical and evidenced no unacceptable flaws present. Additionally, a VT-2 examination performed on the subject components during system pressure test per examination category B-P each refueling outage and category C-H each period provides additional assurance that the structural integrity of the subject components is maintained.
Duration of Proposed Alternative Relief is requested for the Third 10-Year Inservice Inspection Interval of the Inservice Inspection Program for DNPS Units 2 and 3.
Precedents The NRC has previously approved similar relief for Quad Cities Nuclear Power Station, Units 1 and 2, and Dresden Nuclear Power Station, Units 2 and 3. The NRC granted relief for Quad Cities Nuclear Power Station in Reference 1, and the Dresden Nuclear Power Station in Reference 2.
References
- 1. Letter from U. S. NRC to 0. D. Kingsley (Commonwealth Edison Company), "Quad Cities, Units 1 and 2 - Relief Request CR-32 for Third 10-Year Inservice Inspection Interval," dated September 6, 2000 Revision 0
ATTACHMENT 10 CFR 50.55a Request Number CR-26 Relief Requested In Accordance with 10 CFR 50.55a(g)(5)(iii)
Page 4 of 8
- 2. Letter from U. S. NRC to Mr. John L. Skolds (Exelon Generation Company, LLC), "Dresden Nuclear Power Station, Units 2 and 3 - Relief Request CR-24 For Third 10-Year Inservice Inspection Interval," dated January 8, 2003 Revision 0
ATTACHMENT 10 CFR 50.55a Request Number CR-26 Relief Requested In Accordance with 10 CFR 50.55a(g)(5)(iii)
Page 5 of 8 TABLE CR-26.1 UNIT 2 COMPONENTS WITH LESS THAN "ESSENTIALLY 100%" COVERAGE Section XI Component Component Component Condition Limiting Examination Category System Number Description Coverage &
& & Coverage Item No. Line Percent B-A RPV SHELL 2-SC4-FLG SHELL TO REACTOR VESSEL TO UT B1.30 FLANGE FLANGE 88 CONFIGURATION.
B-D RPV N1B-2 NOZZLE TO NOZZLE, RADIUS BLEND UT B3.90 NOZZLE VESSEL WELD AND WELD 20.07 CONFIGURATION.
B-D RPV N2G-2 NOZZLE TO NOZZLE, RADIUS BLEND UT B3.90 NOZZLE VESSEL WELD AND WELD 20.85 CONFIGURATION.
B-D RPV N2H-2 NOZZLE TO NOZZLE, RADIUS BLEND UT B3.90 NOZZLE VESSEL WELD AND WELD 20.85 CONFIGURATION.
B-D RPV N2J-2 NOZZLE TO NOZZLE, RADIUS BLEND UT B3.90 NOZZLE VESSEL WELD AND WELD 20.85 CONFIGURATION.
B-D RPV N2K-2 NOZZLE TO NOZZLE, RADIUS BLEND UT B3.90 NOZZLE VESSEL WELD AND WELD 20.85 CONFIGURATION.
B-D RPV N3A-2 NOZZLE TO NOZZLE, RADIUS BLEND UT B3.90 NOZZLE VESSEL WELD AND WELD 62.5 CONFIGURATION.
B-D RPV N3B-2 NOZZLE TO NOZZLE, RADIUS BLEND UT B3.90 NOZZLE VESSEL WELD AND WELD 62.5 CONFIGURATION.
B-D RPV N3C-2 NOZZLE TO NOZZLE, RADIUS BLEND UT B3.90 NOZZLE VESSEL WELD AND WELD 62.5 CONFIGURATION.
B-D RPV N3D-2 NOZZLE TO NOZZLE, RADIUS BLEND UT B3.90 NOZZLE VESSEL WELD AND WELD 62.5 CONFIGURATION.
B-D RPV N5A-2 NOZZLE TO NOZZLE, RADIUS BLEND UT B3.90 NOZZLE VESSEL WELD AND WELD 20.06 CONFIGURATION.
B-D RPV N8-2 NOZZLE TO NOZZLE, RADIUS BLEND UT B3.90 NOZZLE VESSEL WELD AND WELD 47.24 CONFIGURATION.
B-D RPV N18A-2 NOZZLE TO NOZZLE, RADIUS BLEND UT B3.90 NOZZLE VESSEL WELD AND WELD 20.4 CONFIGURATION.
B-D RPV N18B-2 NOZZLE TO NOZZLE, RADIUS BLEND UT B3.90 NOZZLE VESSEL WELD AND WELD 20.4 CONFIGURATION.
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ATTACHMENT 10 CFR 50.55a Request Number CR-26 Relief Requested In Accordance with 10 CFR 50.55a(g)(5)(iii)
Page 6 of 8 TABLE CR-26.1 UNIT 2 COMPONENTS WITH LESS THAN "ESSENTIALLY 100%" COVERAGE Section Xi Component Component Component Condition Limiting Examination Category System Number Description Coverage &
& & Coverage Item No. Line Percent B-D RPV N12-2 NOZZLE TO NOZZLE, RADIUS BLEND UT B3.90 NOZZLE VESSEL WELD AND WELD 75.31 CONFIGURATION.
B-D RPV N20B-2 NOZZLE TO NOZZLE, RADIUS BLEND UT B3.90 NOZZLE VESSEL WELD AND WELD 75.32 CONFIGURATION.
B-D RPV N8-1 NOZZLE INNER NOZZLE, RADIUS BLEND UT B3.100 NOZZLE RADIUS SECTION AND WELD 83.6 CONFIGURATION.
B-D RPV N18A-1 NOZZLE INNER NOZZLE, RADIUS BLEND UT B3.100 NOZZLE RADIUS SECTION AND WELD 83.6 CONFIGURATION.
B-D RPV N18B-1 NOZZLE INNER NOZZLE, RADIUS BLEND UT B3.100 NOZZLE RADIUS SECTION AND WELD 83.6 CONFIGURATION.
B-M-1 MS ERV 2/3-203- VALVE BODY INTERNAL CAGE RT B12.40 3B/C/D/E WELD INTERFERENCE 86.32 C-C CRD M-1152D-1201 INTEGRALLY BOX GUIDE & BRANCH MT C3.20 0318A-20 WELDED LINE INTERFERENCE 82 ATTACHMENT WITH SHEAR LUG ATTACHMENT.
C-C CRD M-1152D-1251 INTEGRALLY BOX GUIDE & BRANCH MT C3.20 03188-20 WELDED LINE INTERFERENCE 62.5 ATTACHMENT WITH SHEAR LUG ATTACHMENT.
C-C HPCI M-1151D-10 INTEGRALLY BOX GUIDE MT C3.20 2304-14 WELDED INTERFERENCE WITH 81.63 ATTACHMENT SHEAR LUG ATTACHMENT.
C-C ISCO M-1163D-261 INTEGRALLY PIPE CLAMP PT C3.20 1302-14 WELDED INTERFERENCE WITH 75 ATTACHMENT SHEAR LUG ATTACHMENT.
C-C ISCO M-1163D-254 INTEGRALLY PIPE CLAMP PT C3.20 1303-12 WELDED INTERFERENCE WITH 78 ATTACHMENT SHEAR LUG ATTACHMENT.
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ATTACHMENT 10 CFR 50.55a Request Number CR-26 Relief Requested In Accordance with 10 CFR 50.55a(g)(5)(iii)
Page 7 of 8 TABLE CR-26.2 UNIT 3 COMPONENTS WITH LESS THAN "ESSENTIALLY 100%" COVERAGE Section Xi Component Component Component Condition Limiting Examination Category System Number Description Coverage &
& & Coverage Item No. Line Percent B-D RPV N2A-2 NOZZLE TO NOZZLE, RADIUS BLEND UT B3.90 NOZZLE VESSEL WELD AND WELD 20.85 CONFIGURATION.
B-D RPV N2C-2 NOZZLE TO NOZZLE, RADIUS BLEND UT B3.90 NOZZLE VESSEL WELD AND WELD 20.85 CONFIGURATION.
B-D RPV N2F-2 NOZZLE TO NOZZLE, RADIUS BLEND UT B3.90 NOZLE VESSEL WELD AND WELD 20.85 CONFIGURATION.
B-D RPV N2H-2 NOZZLE TO NOZZLE, RADIUS BLEND UT B3.90 NOZZLE VESSEL WELD AND WELD 20.85 CONFIGURATION.
B-D RPV N2J-2 NOZZLE TO NOZZLE, RADIUS BLEND UT B3.90 NOZZLE VESSEL WELD AND WELD 20.85 CONFIGURATION.
B-D RPV N2K-2 NOZZLE TO NOZZLE, RADIUS BLEND UT B3.90 NOZZLE VESSEL WELD AND WELD 20.85 CONFIGURATION.
B-D RPV N3A-2 NOZZLE TO NOZZLE, RADIUS BLEND UT B3.90 NOZZLE VESSEL WELD AND WELD 62.5 CONFIGURATION.
B-D RPV N3B-2 NOZZLE TO NOZZLE, RADIUS BLEND UT B3.90 NOZZLE VESSEL WELD AND WELD 62.5 CONFIGURATION.
B-D RPV N9-2 NOZZLE TO NOZZLE, RADIUS BLEND UT B3.90 NOZZLE VESSEL WELD AND WELD 44 CONFIGURATION.
B-D RPV N20A-2 NOZZLE TO NOZZLE, RADIUS BLEND UT B3.90 NOZZLE VESSEL WELD AND WELD 75.32 CONFIGURATION.
B-D RPV N20B-2 NOZZLE TO NOZZLE, RADIUS BLEND UT B3.90 NOZZLE VESSEL WELD AND WELD 75.32 CONFIGURATION.
B-M-1 MS ERV 2/3-203- VALVE BODY INTERNAL CAGE RT B12.40 3B/C/D/E WELD INTERFERENCE 86.46 C-B 1SCO 8-8 NOZZLE TO NOZZLE, RADIUS BLEND UT C2.21 1303A-8 SHELL WELD AND WELD 44.56
__ CONFIGURATION.
C-B ISCO 8-9 NOZZLE TO NOZZLE, RADIUS BLEND UT C2.21 13038-8 SHELL WELD AND WELD 44.56 CONFIGURATION.
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ATTACHMENT 10 CFR 50.55a Request Number CR-26 Relief Requested In Accordance with 10 CFR 50.55a(g)(5)(iii)
Page 8 of 8 TABLE CR-26.2 UNIT 3 COMPONENTS WITH LESS THAN "ESSENTIALLY 100%" COVERAGE Section Xi Component Component Component Condition Limiting Examination Category System Number Description Coverage &
& & Coverage Item No. Line Percent C-C CRD M-1188D-1001 INTEGRALLY BOX GUIDE MT C3.20 0409B-20 WELDED INTERFERENCE WITH 79.66 ATTACHMENT SHEAR LUG ATTACHMENT.
C-C ISCO M-1199D-261 INTEGRALLY PIPE CLAMP PT C3.20 1302-14 WELDED INTERFERENCE WITH 77.16 ATTACHMENT SHEAR LUG ATTACHMENT.
C-C CORE SPRAY M-3409-26 INTEGRALLY BOX GUIDE MT C3.20 1403-12 WELDED INTERFERENCE WITH 88.24 ATTACHMENT SHEAR LUG ATTACHMENT.
C-C CORE SPRAY M-3408-08 INTEGRALLY PIPE CLAMP MT C3.20 1404-12 WELDED INTERFERENCE WITH 78.72 ATTACHMENT SHEAR LUG ATTACHMENT.
C-C CORE SPRAY M-3408-10 INTEGRALLY BOX GUIDE MT C3.20 1404-12 WELDED INTERFERENCE WITH 85.7 ATTACHMENT SHEAR LUG ATTACHMENT.
C-C LPCI M-3414-10 INTEGRALLY BOX GUIDE MT C3.20 1504-18 WELDED INTERFERENCE WITH 85.71 ATTACHMENT SHEAR LUG ATTACHMENT.
C-C HPCI M-1187D-86 INTEGRALLY PIPE CLAMP MT C3.20 2304-14 WELDED INTERFERENCE WITH 83.33 ATTACHMENT SHEAR LUG ATTACHMENT.
C-C HPCI M-3412-03 INTEGRALLY PIPE CLAMP MT C3.20 2306-24 WELDED INTERFERENCE WITH 85.71 ATTACHMENT SHEAR LUG ATTACHMENT.
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