View source for SVPLTR 04-0024, Relief Request CR-26, Inservice Inspection Program Relief Regarding Examination Coverage for Third 1 0-Year Inservice Inspection Interval

{{Adams
| number = ML041320487
| issue date = 05/04/2004
| title = Relief Request CR-26, Inservice Inspection Program Relief Regarding Examination Coverage for Third 1 0-Year Inservice Inspection Interval
| author name = Bost D
| author affiliation = Exelon Generation Co, LLC, Exelon Nuclear
| addressee name = 
| addressee affiliation = NRC/Document Control Desk, NRC/NRR
| docket = 05000237, 05000249
| license number = DPR-019, DPR-025
| contact person = 
| case reference number = SVPLTR: #04-0024
| document type = Letter type:SVPLTR
| page count = 10
| project = 
| stage = Request
}}

=Text=
{{#Wiki_filter: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.
Revision 0}}