ML12076A027: Difference between revisions
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| number = ML12076A027 | | number = ML12076A027 | ||
| issue date = 03/06/2012 | | issue date = 03/06/2012 | ||
| title = | | title = Relief Requests for Limited Coverage Inspections Response to Request for Additional Information | ||
| author name = Gebbie J | | author name = Gebbie J | ||
| author affiliation = Indiana Michigan Power Co | | author affiliation = Indiana Michigan Power Co | ||
| addressee name = | | addressee name = | ||
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=Text= | =Text= | ||
{{#Wiki_filter:z INDIANA MICHIGAN Indiana Michigan Power POWER* One Cook Place Bridgman, | {{#Wiki_filter:z INDIANA MICHIGAN Indiana Michigan Power POWER* One Cook Place Bridgman, M149106 A unit ofAmerican ElectricPower Indiana MichiganPower.com March 6, 2012 AEP-NRC-2012-2 10 CFR 50.4 Docket Nos.: 50-315 50-316 U. S. Nuclear Regulatory Commission ATTN: Document Control Desk Washington, D. C. 20555-0001 Donald C. Cook Nuclear Plant Units 1 and 2 RELIEF REQUESTS FOR LIMITED COVERAGE INSPECTIONS RESPONSE TO REQUEST FOR ADDITIONAL INFORMATION | ||
==References:== | ==References:== | ||
: 1. Letter from J. P. Gebbie, Indiana Michigan Power Company, to U. S. Nuclear Regulatory Commission Document Control Desk, "Donald C. Cook Nuclear Plant Units 1 and 2, Relief Requests for Limited Coverage Examinations Performed in the Third 10-Year Inspection Interval," AEP-NRC-2011-23, dated April 8, 2011, Agencywide Documents Access and Management System (ADAMS) Accession No. | : 1. Letter from J. P. Gebbie, Indiana Michigan Power Company, to U. S. Nuclear Regulatory Commission Document Control Desk, "Donald C. Cook Nuclear Plant Units 1 and 2, Relief Requests for Limited Coverage Examinations Performed in the Third 10-Year Inspection Interval," AEP-NRC-2011-23, dated April 8, 2011, Agencywide Documents Access and Management System (ADAMS) Accession No. ML11110A042 | ||
By Reference 2, the NRC communicated a draft Request for Additional Information (RAI) to I&M for information needed to complete the relief request evaluation. | : 2. Memorandum from P. S. Tam, U. S. Nuclear Regulatory Commission, to H. L. Etheridge, Indiana Michigan Power Company, "D. C. Cook - Draft RAI on Proposed Relief Requests ISIR-33 thru ISIR-42 (TAC Nos. ME6087, ME6088)," October 21, 2011, ADAMS Accession No. ML112940700 By Reference 1, Indiana Michigan Power Company (I&M), the licensee for Donald C. Cook Nuclear Plant (CNP) Units 1 and 2, requested relief from American Society of Mechanical Engineers Boiler and Pressure Code requirements for various in-service inspection (ISI) activities on the basis that the required examination coverage is impractical due to physical obstructions and limitations imposed by design, geometry, and materials of construction of the subject components. By Reference 2, the NRC communicated a draft Request for Additional Information (RAI) to I&M for information needed to complete the relief request evaluation. | ||
Via a teleconference on October 31, 2011, and e-mail exchanges with the NRC Licensing Project Manager on January 31 and February 14, 2012, a due date of March 7, 2012 was established. | Via a teleconference on October 31, 2011, and e-mail exchanges with the NRC Licensing Project Manager on January 31 and February 14, 2012, a due date of March 7, 2012 was established. | ||
U. S. Nuclear Regulatory Commission AEP-NRC-2012-2 Page 2 I&M's response to the RAI is provided as Enclosure 1 to this letter. A revised copy of Relief Requests (RR) ISIR-33 through ISIR-42, without the pages of the Supporting Documentation sections in the RRs provided in Reference 1, is provided as Enclosure 2 to assist in your review.There are no new or revised regulatory commitments made as a part of this submittal. | |||
Should you have any questions, please contact Mr. Michael K. Scarpello, Regulatory Affairs Manager, at (269) 466-2649.Sincerely, Joel P. Gebbie Site Vice President JRW/jen | U. S. Nuclear Regulatory Commission AEP-NRC-2012-2 Page 2 I&M's response to the RAI is provided as Enclosure 1 to this letter. A revised copy of Relief Requests (RR) ISIR-33 through ISIR-42, without the pages of the Supporting Documentation sections in the RRs provided in Reference 1, is provided as Enclosure 2 to assist in your review. | ||
There are no new or revised regulatory commitments made as a part of this submittal. Should you have any questions, please contact Mr. Michael K. Scarpello, Regulatory Affairs Manager, at (269) 466-2649. | |||
Sincerely, Joel P. Gebbie Site Vice President JRW/jen | |||
==Enclosures:== | ==Enclosures:== | ||
: 1. Response to Request for Additional Information | : 1. Response to Request for Additional Information | ||
: 2. Revised Relief Requests ISIR-33 through ISIR-42 c: J. T. King, MPSC S. M. Krawec, AEP Ft. Wayne, w/o enclosures MDEQ -WHMD/RPS NRC Resident Inspector C. D. Pederson, NRC Region III P. S. Tam, NRC Washington, DC | : 2. Revised Relief Requests ISIR-33 through ISIR-42 c: J. T. King, MPSC S. M. Krawec, AEP Ft. Wayne, w/o enclosures MDEQ - WHMD/RPS NRC Resident Inspector C. D. Pederson, NRC Region III P. S. Tam, NRC Washington, DC to AEP-NRC-2012-2 Page I RESPONSE TO REQUEST FOR ADDITIONAL INFORMATION FOR RELIEF REQUESTS FOR LIMITED COVERAGE EXAMINATION RELIEF REQUESTS ISIR-33 THROUGH ISIR 42 | ||
==References:== | ==References:== | ||
: 1. Letter from J. P. Gebbie, Indiana Michigan Power Company, to U. S. Nuclear Regulatory Commission Document Control Desk, "Donald C. Cook Nuclear Plant Units 1 and 2, Relief Requests for Limited Coverage Examinations Performed in the Third 10-Year Inspection Interval," AEP-NRC-2011-23, dated April 8, 2011, Agencywide Documents Access and Management System (ADAMS) Accession Number | : 1. Letter from J. P. Gebbie, Indiana Michigan Power Company, to U. S. Nuclear Regulatory Commission Document Control Desk, "Donald C. Cook Nuclear Plant Units 1 and 2, Relief Requests for Limited Coverage Examinations Performed in the Third 10-Year Inspection Interval," AEP-NRC-2011-23, dated April 8, 2011, Agencywide Documents Access and Management System (ADAMS) Accession Number ML11110A042 By Reference 1, Indiana Michigan Power Company (I&M), the licensee for Donald C. Cook Nuclear Plant (CNP) Units 1 and 2, submitted Requests for Relief, ISIR-33 thru ISIR-42, from the requirements of the American Society of Mechanical Engineers (ASME) Boiler and Pressure Vessel Code, Section Xl, for CNP Units 1 and 2. The requests for relief apply to the third 10-year inservice inspection interval, in which I&M adopted the 1989 Edition with no Addenda of ASME Code Section Xl as the Code of Record. | ||
I&M's response to the request for additional information (RAI) is provided below. As a separate enclosure to this letter (Enclosure 2), the revised Relief Requests (RRs) ISIR-33 through ISIR-42 are provided with the applicable information indicated in the I&M response below, with the exception of the pages of the Supporting Documentation sections in the RRs provided in Reference 1.NRC Item I -Generic Questions for RRs ISIR-33 through ISIR-42 The licensee did not identify the request for relief that was requested for each CNP, Unit.Designate the CNP Unit or Units for each request for relief.Where both a surface examination and volumetric examinations were required by the ASME Code, provide the results of the surface examinations for each relief request, if it applies. State if any indications were identified. | The NRC staff reviewed the submitted information and determined that additional information was needed to complete the evaluation. I&M's response to the request for additional information (RAI) is provided below. As a separate enclosure to this letter (Enclosure 2), the revised Relief Requests (RRs) ISIR-33 through ISIR-42 are provided with the applicable information indicated in the I&M response below, with the exception of the pages of the Supporting Documentation sections in the RRs provided in Reference 1. | ||
State for each examination if ASME Code, Section XI, Appendix VIII methodology was used for the welds contained in RRs ISIR-34 through ISIR-42.For RRs ISIR-33 through ISIR-42 state whether or not any indications were identified during the examinations. | NRC Item I - Generic Questions for RRs ISIR-33 through ISIR-42 The licensee did not identify the request for relief that was requested for each CNP, Unit. | ||
If any, state the disposition of the indications. | Designate the CNP Unit or Units for each request for relief. | ||
Where both a surface examination and volumetric examinations were required by the ASME Code, provide the results of the surface examinations for each relief request, if it applies. State if any indications were identified. | |||
State for each examination if ASME Code, Section XI, Appendix VIII methodology was used for the welds contained in RRs ISIR-34 through ISIR-42. | |||
For RRs ISIR-33 through ISIR-42 state whether or not any indications were identified during the examinations. If any, state the disposition of the indications. | |||
I&M Response to NRC Item 1 A new column was added to each Table 1 in RRs ISIR-33 through ISIR-42 to identify the applicable CNP unit. | I&M Response to NRC Item 1 A new column was added to each Table 1 in RRs ISIR-33 through ISIR-42 to identify the applicable CNP unit. | ||
to AEP-NRC-2012-2 Page 2 Examinations that required both a surface and volumetric examination are contained within RR ISIR-35 (component IDs 2-RC-26 and 2-RC-27 only), RR ISIR-36, and RR ISIR-37. These examinations are described in Section 6 of RR ISIR-35 (as revised), RR ISIR-36, and RR ISIR-37. There were no surface indications identified. | |||
With the exception of ISIR-40, which is a relief request for less than 100% of the Surface Area, the column titled "Ultrasonic Examination Coverage Attained (%)" in Table 1 of each relief request was revised to indicate whether a PDI qualified examination was performed by adding"PDI (YIN)". Components examined using Appendix VIII methodology, as modified by the Performance Demonstration Initiative and 10 CFR 50.55a, are annotated with "Y". Those annotated with "N" have a parenthetical reference to the examination requirement. | With the exception of ISIR-40, which is a relief request for less than 100% of the Surface Area, the column titled "Ultrasonic Examination Coverage Attained (%)" in Table 1 of each relief request was revised to indicate whether a PDI qualified examination was performed by adding "PDI (YIN)". Components examined using Appendix VIII methodology, as modified by the Performance Demonstration Initiative and 10 CFR 50.55a, are annotated with "Y". Those annotated with "N" have a parenthetical reference to the examination requirement. | ||
For all relief requests, the column titled "Remarks" in Table 1 identifies if there were any indications and also provides the disposition. | For all relief requests, the column titled "Remarks" in Table 1 identifies if there were any indications and also provides the disposition. | ||
NRC Item 2 -RR ISIR-33 ASME Code, Section XI, Examination Category B-A. Items B1.11, B1.12, B1.21, B1.22, and B1.30 Pressure Retaining Welds in Reactor Pressure Vessel and ASME Code, Section XI, Examination Category B-D, Item 3.90 Based on the limited descriptions and sketches provided in the submittal, it appears that examinations for ASME Code, Section, Xl, Table IWB 2500-1, Category B-A, Items B1.11, B1.12, B1.21, and B1.22 were performed from the inside surface of the reactor pressure vessel (RPV). State whether access to the subject welds from the outside of the RPV is possible, and discuss the potential for increasing ASME Code volumetric coverage by applying examinations from the outside surface of the RPV.Discuss whether other welds in ASME Code, Section XI, Examination Category B-A have been examined to the full, ASME Code-required volumetric extent, whether any indications were found as a result of these examinations, and the final disposition of the indications. | NRC Item 2 - RR ISIR-33 ASME Code, Section XI, Examination Category B-A. Items B1.11, B1.12, B1.21, B1.22, and B1.30 Pressure Retaining Welds in Reactor Pressure Vessel and ASME Code, Section XI, Examination Category B-D, Item 3.90 Based on the limited descriptions and sketches provided in the submittal, it appears that examinations for ASME Code, Section, Xl, Table IWB 2500-1, Category B-A, Items B1.11, B1.12, B1.21, and B1.22 were performed from the inside surface of the reactor pressure vessel (RPV). State whether access to the subject welds from the outside of the RPV is possible, and discuss the potential for increasing ASME Code volumetric coverage by applying examinations from the outside surface of the RPV. | ||
Discuss whether other welds in ASME Code, Section XI, Examination Category B-A have been examined to the full, ASME Code-required volumetric extent, whether any indications were found as a result of these examinations, and the final disposition of the indications. | |||
I&M Response to NRC Item 2 Access to the exterior of the reactor vessel is not practical due to higher radiation exposure and limited access for personnel and equipment caused by the close proximity of building structures/concrete and installed insulation and insulation support members. Greater coverage is achieved via the inside surface and results in less radiation exposure to personnel. | I&M Response to NRC Item 2 Access to the exterior of the reactor vessel is not practical due to higher radiation exposure and limited access for personnel and equipment caused by the close proximity of building structures/concrete and installed insulation and insulation support members. Greater coverage is achieved via the inside surface and results in less radiation exposure to personnel. | ||
Additionally, some of the same interferences that exist for examination from the inside of the vessel are also present on the outside of the vessel (such as the bottom mounted instrument penetrations). | Additionally, some of the same interferences that exist for examination from the inside of the vessel are also present on the outside of the vessel (such as the bottom mounted instrument penetrations). Therefore, I&M does not consider that additional volumetric coverage can be attained without significant additional radiation exposure and additional resources to modify existing structures to allow for access. | ||
Therefore, I&M does not consider that additional volumetric coverage can be attained without significant additional radiation exposure and additional resources to modify existing structures to allow for access.Twenty ASME Category B-A welds received examination during the Third ISI Interval. | Twenty ASME Category B-A welds received examination during the Third ISI Interval. Ten had coverage greater than 90%. There were no indications in the twenty ASME Category B-A welds that were examined. | ||
Ten had coverage greater than 90%. There were no indications in the twenty ASME Category B-A welds that were examined. | to AEP-NRC-2012-2 Page 3 NRC Item 3 - RR ISIR-36 ASME Code, Section Xl, Examination Category B-F Pressure Retaining Welds The difficulties on obtaining coverage in these welds seem to be caused by the use of fixed-angle probes with a limited area available for scanning. Provide a discussion on alternative examination methods and techniques such as phased-array ultrasonic (UT) techniques (line scan or raster) that cover many angles that can be used to obtain greater coverage for welds covered in ISIR-36 I&M Response to NRC Item 3 When these examinations were performed, Phased Array (PA) techniques were not yet qualified under the Performance Demonstration Initiative (PDI) and were therefore not available for use. Use of radiography would pose a significant hardship due to the impact on resources. | ||
Provide a discussion on alternative examination methods and techniques such as phased-array ultrasonic (UT)techniques (line scan or raster) that cover many angles that can be used to obtain greater coverage for welds covered in ISIR-36 I&M Response to NRC Item 3 When these examinations were performed, Phased Array (PA) techniques were not yet qualified under the Performance Demonstration Initiative (PDI) and were therefore not available for use. Use of radiography would pose a significant hardship due to the impact on resources. | |||
Radiography would require evacuation of containment during refueling outages for extended periods of time. Additionally, radiography has not been demonstrated as an equivalent technique to PDI qualified examinations. | Radiography would require evacuation of containment during refueling outages for extended periods of time. Additionally, radiography has not been demonstrated as an equivalent technique to PDI qualified examinations. | ||
NRC Item 4 -RR ISIR-37 ASME Code, Section Xl, Examination Category B-J Pressure Retaining Welds in Piping Identify the system(s), and nominal pipe diameters or components for welds 1-RH-28-05F, 1-SI-22-18F, 1-SI-23-17F, I-RC-5-011F, 1-SI-33-23S, 2-RC-22-01, and 2-RC-28-23. | NRC Item 4 - RR ISIR-37 ASME Code, Section Xl, Examination Category B-J Pressure Retaining Welds in Piping Identify the system(s), and nominal pipe diameters or components for welds 1-RH-28-05F, 1-SI-22-18F, 1-SI-23-17F, I-RC-5-011F, 1-SI-33-23S, 2-RC-22-01, and 2-RC-28-23. | ||
State the material of construction of the piping, valves, and Tees. Identify the dissimilar metal welds, if any in Table I of RR ISIR-37.I&M ResDonse to NRC Item 4 The table below provides the information requested above: Weld ID System Nominal Pipe Materials DM Weld (Y/N)Size (NPS)1-RH-28-05F Residual Heat 14.0" NPS Both Stainless N Pipe to Pipe | State the material of construction of the piping, valves, and Tees. Identify the dissimilar metal welds, if any in Table I of RR ISIR-37. | ||
a) As applicable, describe NDE equipment (UT scanning apparatus) and details of the listed obstructions (size, shape, proximity to the weld, etc.) to demonstrate accessibility limitations. | I&M ResDonse to NRC Item 4 The table below provides the information requested above: | ||
Discuss whether alternative methods or advanced technologies could be employed to maximize ASME Code coverage.b) Fully clarify the wave modality and insonification angles used for all ultrasonic examinations. | Weld ID System Nominal Pipe Materials DM Weld (Y/N) | ||
Size (NPS) 1-RH-28-05F Residual Heat 14.0" NPS Both Stainless N Removal Steel Pipe to Pipe Type 316 1-SI-22-18F Safety Injection 6.0" NPS Both Stainless N Pipe to Valve Steel Type 316 to AEP-NRC-2012-2 Page 4 Weld ID System Nominal Pipe Materials DM Weld (Y/N) | |||
Size (NPS) 1-SI-23-17F Safety Injection 6.0" NPS Both Stainless N Steel Pipe to valve Type 316 1-RC-5-01F Reactor 14.0" NPS Pipe Stainless N Coolant Steel Branch to Pipe Type 316 Branch - | |||
SA-351 Grade CF8M 1-SI-33-23S Safety Injection 10.0" NPS Pipe - Stainless N Steel Tee to Pipe Type 316 Tee - SA-403 Grade WP 316 2-RC-22-01 Reactor 6.0" NPS Pipe Stainless N Coolant Steel Safe End to Elbow Type 316/ Safe End - SA-351 Grade CF8M 2-RC-28-23 Reactor 4.0" NPS Both Stainless N Coolant Steel Tee to Pipe Type 316 2-SI-56-19 Safety Injection 10.0" NPS Pipe and Tee N Stainless Steel Tee to Pipe Type 316 2-RH-33-01 Residual Heat 14.0" NPS Pipe and Tee N Removal Stainless Steel Tee to Pipe Type 316 to AEP-NRC-2012-2 Page 5 Weld ID System Nominal Pipe Materials DM Weld (Y/N) | |||
Size (NPS) 2-RC-17-08N Reactor 27.5" Inside Branch: N Branch to Pipe Coolant Diameter to Stainless Steel 10.0" NPS WP 316 Pipe: Cast Austenitic Stainless Steel SA-351 Grade CF8M NRC Item 5 - RR ISIR-38 ASME Code, Section X1I Examination Category C-A Pressure Retaining Pressure Vessels Please submit detailed and specific information to support the bases for limited volumetric coverage in ASME Code, Section XI, Examination Category C-A components, and therefore, demonstrate impracticality. | |||
a) As applicable, describe NDE equipment (UT scanning apparatus) and details of the listed obstructions (size, shape, proximity to the weld, etc.) to demonstrate accessibility limitations. Discuss whether alternative methods or advanced technologies could be employed to maximize ASME Code coverage. | |||
b) Fully clarify the wave modality and insonification angles used for all ultrasonic examinations. | |||
Please also state the materials of construction and the wall thickness for the Residual Heat Removal heat exchanger. | Please also state the materials of construction and the wall thickness for the Residual Heat Removal heat exchanger. | ||
Identify the system(s) and component(s) for the welds contained in Table 1 of RR ISIR-38 I&M Response to NRC Item 5 Details and specific information for each limitation on each Component ID are contained in Table 1 and in the Supporting Documentation section of the RR submitted by Reference | Identify the system(s) and component(s) for the welds contained in Table 1 of RR ISIR-38 I&M Response to NRC Item 5 Details and specific information for each limitation on each Component ID are contained in Table 1 and in the Supporting Documentation section of the RR submitted by Reference 1. The column titled "Remarks" in Table 1 of the RR provides a brief description of the limitation(s) for each component. The Supporting Documentation section for this RR provides details, in the form of Nondestructive Examination (NDE) datasheets, for each component of the area not scanned due to the limitation. | ||
a) With the exception of STM-24-04, the NDE equipment used was standard manual ultrasonic scopes, transducers and wedges. STM-24-04 was examined using the vendor's Autoscan 2000 (an electro-mechanical track-guided system) equipment and the Micro-Tomoscan data acquisition system. When these examinations were performed, to AEP-NRC-2012-2 Page 6 no advanced ultrasonic or radiographic techniques were qualified for use; therefore, no alternative examinations were explored. An annotated picture has been added to RR ISIR-38, Supporting Documentation section, to provide additional detail of the obstructions for component W-CTSHEX. An annotated excerpt of a plant construction drawing has been added to RR ISIR-38, Supporting Documentation section, to provide additional detail of the obstructions for component 2-BIT-A. For component STM-24-04, there are no pictures or plant drawings available that can provide additional details of the obstructions beyond what has already been provided in RR ISIR-38 by Reference 1. | |||
The Supporting Documentation section for this RR provides details, in the form of Nondestructive Examination (NDE) datasheets, for each component of the area not scanned due to the limitation. | b) A summary of the wave modality and insonification angles are provided in the table below. | ||
a) With the exception of STM-24-04, the NDE equipment used was standard manual ultrasonic scopes, transducers and wedges. STM-24-04 was examined using the vendor's Autoscan 2000 (an electro-mechanical track-guided system) equipment and the Micro-Tomoscan data acquisition system. When these examinations were performed, | Component ID Insonification Angle Wave Mode* | ||
An annotated picture has been added to RR ISIR-38, Supporting Documentation section, to provide additional detail of the obstructions for component W-CTSHEX. | W-CTSHEX 00 L, 450 S, 600 L 2-BIT-A 0° L, 450 S, 600 S STM-24-04 450 S, 600 S | ||
An annotated excerpt of a plant construction drawing has been added to RR ISIR-38, Supporting Documentation section, to provide additional detail of the obstructions for component 2-BIT-A. For component STM-24-04, there are no pictures or plant drawings available that can provide additional details of the obstructions beyond what has already been provided in RR ISIR-38 by Reference 1.b) A summary of the wave modality and insonification angles are provided in the table below.Component ID Insonification Angle Wave Mode*W-CTSHEX 00 L, 450 S, 600 L 2-BIT-A 0° L, 450 S, 600 S STM-24-04 450 S, 600 S* L= Longitudinal, S= Shear There is no request for relief for any examination on any Residual Heat Removal Heat Exchanger at CNP.W-CTSHEX is the West Containment Spray System Heat Exchanger and is constructed of Carbon Steel with Stainless Steel Cladding.2-BIT-A is the Unit 2 Boron Injection Tank in Safety Injection portion of the Emergency Core Cooling System and is constructed of carbon steel with stainless steel cladding.STM-24-04 is the Unit 2 #4 Steam Generator and is constructed of carbon steel with stainless steel cladding.NRC Item 6 -RR ISIR-39 ASME Code, Section Xl, Examination Category C-B Pressure Nozzle Welds in Vessels Identify the system(s) and component(s) for the welds contained in Table 1 of RR ISIR-39.I&M Response to NRC Item 6 The one component in RR ISIR-39 is STM-14-FWN, which is the Unit 1 #4 Steam Generator Feedwater Nozzle to Shell weld. | * L= Longitudinal, S= Shear There is no request for relief for any examination on any Residual Heat Removal Heat Exchanger at CNP. | ||
Enclosure 1 to AEP-NRC-2012-2 Page 7 NRC Item 7 -RR ISIR-40 ASME Code, Section Xl, Category C-C Integral Attachments for Vessels, Piping Pumps, and Valves Table I of RR ISIR-40 describes the examination performed as "UT" while the supporting documentation shows that dye penetrant (PT) examinations were performed. | W-CTSHEX is the West Containment Spray System Heat Exchanger and is constructed of Carbon Steel with Stainless Steel Cladding. | ||
Clarify Table I of RR ISIR-40. Does Table I of RR ISIR-40 contain a typographical error or were UT examinations performed on the subject welds?State the materials of construction for the welds and attachments. | 2-BIT-A is the Unit 2 Boron Injection Tank in Safety Injection portion of the Emergency Core Cooling System and is constructed of carbon steel with stainless steel cladding. | ||
Identify the system(s) and components for the subject welds in Table I of RR ISIR-40.I&M Response to NRC Item 7 There was a typographical error in Section 3. RR ISIR-40 Section 3 should have identified that the relief was for limitations preventing 100% surface examination of the required area and not a volumetric examination. | STM-24-04 is the Unit 2 #4 Steam Generator and is constructed of carbon steel with stainless steel cladding. | ||
The remaining Sections of the relief correctly identify the surface method and the impracticality for the surface examination. | NRC Item 6 - RR ISIR-39 ASME Code, Section Xl, Examination Category C-B Pressure Nozzle Welds in Vessels Identify the system(s) and component(s) for the welds contained in Table 1 of RR ISIR-39. | ||
RR ISIR-40 has been corrected to reflect this.The materials for all welds and attachments are carbon steel. For all welds in Table 1 of RR ISIR-40, the system is Main Steam. The components for the welds are described in the"Weld Description" column of Table 1 of RR ISIR-40. The component for 1-MS-6-11S-PS is main steam piping. The component for MSIV-MRV-230-S2 is a support for a main steam isolation valve.NRC Item 8 -RR ISIR-41 ASME Code, Section Xl, C-F-1 Pressure Retaining Welds in Austenitic Stainless Steel of High Alloy Piping Identify the system(s), and nominal pipe diameters or components for welds 1 -CTS-2-18F, 1-SI-2-42S, I-SI-24-06F, I -SI-30-08F, 1-SI-11A-01S, 1-SI-11-01S, I-S1-11-05F, I-SI-74-01F, 2-SI-42-OIS, and 2-SI-42-03F. | I&M Response to NRC Item 6 The one component in RR ISIR-39 is STM-14-FWN, which is the Unit 1 #4 Steam Generator Feedwater Nozzle to Shell weld. | ||
The diagram for weld 1-SI-24-06F appears to be incorrect or mislabeled. | |||
Where one would expect the diagram for 1-SI-24-06F (Pages 186 and 187 of the licensee's submittal dated April 8, 2011) there are two diagrams labeled 1-S1-152N with image dates of 12/30/1899 and 04/14/1997. (No relief is requested for I-S1-152N.) | Enclosure 1 to AEP-NRC-2012-2 Page 7 NRC Item 7 - RR ISIR-40 ASME Code, Section Xl, Category C-C Integral Attachments for Vessels, Piping Pumps, and Valves Table I of RR ISIR-40 describes the examination performed as "UT" while the supporting documentation shows that dye penetrant (PT) examinations were performed. Clarify Table I of RR ISIR-40. Does Table I of RR ISIR-40 contain a typographical error or were UT examinations performed on the subject welds? | ||
Clarify and provide a diagram or photograph identifying weld 1-SI-24-06F. | State the materials of construction for the welds and attachments. | ||
It appears that additional coverage could be obtained for welds 1-SI-11A-01S or 1-SI-11-01S by unbolting the pipe and examining them from the inner-diameter. | Identify the system(s) and components for the subject welds in Table I of RR ISIR-40. | ||
Are there any plans to unbolt either of these fixtures in future inspection periods?State the material of construction of the piping, valves, elbows, flange, and tees. Identify the dissimilar metal welds in Table I of RR ISIR-41, if any. | I&M Response to NRC Item 7 There was a typographical error in Section 3. RR ISIR-40 Section 3 should have identified that the relief was for limitations preventing 100% surface examination of the required area and not a volumetric examination. The remaining Sections of the relief correctly identify the surface method and the impracticality for the surface examination. RR ISIR-40 has been corrected to reflect this. | ||
The materials for all welds and attachments are carbon steel. For all welds in Table 1 of RR ISIR-40, the system is Main Steam. The components for the welds are described in the "Weld Description" column of Table 1 of RR ISIR-40. The component for 1-MS-6-11S-PS is main steam piping. The component for MSIV-MRV-230-S2 is a support for a main steam isolation valve. | |||
A new image is provided, in the Supporting Documentation section of RR ISIR-41, which clearly identifies the location of 1-SI-24-06F on the image. For reference, 1-SI-1 52N is the label for the check valve in the image.There are no plans to disassemble any portion of the piping system to examine 1-SI-1i1A-01S or 1-SI-11-01S from the inner diameter.There are no dissimilar metal welds contained in RR-ISIR-41. | NRC Item 8 - RR ISIR-41 ASME Code, Section Xl, C-F-1 Pressure Retaining Welds in Austenitic Stainless Steel of High Alloy Piping Identify the system(s), and nominal pipe diameters or components for welds 1 -CTS-2-18F, 1-SI-2-42S, I-SI-24-06F, I -SI-30-08F, 1-SI-11A-01S, 1-SI-11-01S, I-S1-11-05F, I-SI-74-01F, 2-SI-42-OIS, and 2-SI-42-03F. | ||
NRC Item 9 -RR ISIR-42 ASME Code. Section Xl. Examination Cateqorv R-A. Items R1111.R1.16, and R.120 Submit detailed and specific information to support the bases for limited volumetric coverage in ASME Code, Section XI, Examination Category R-A piping welds, and therefore, demonstrate impracticality. | The diagram for weld 1-SI-24-06F appears to be incorrect or mislabeled. Where one would expect the diagram for 1-SI-24-06F (Pages 186 and 187 of the licensee's submittal dated April 8, 2011) there are two diagrams labeled 1-S1-152N with image dates of 12/30/1899 and 04/14/1997. (No relief is requested for I-S1-152N.) Clarify and provide a diagram or photograph identifying weld 1-SI-24-06F. | ||
As applicable, describe NDE equipment (UT scanning apparatus). | It appears that additional coverage could be obtained for welds 1-SI-11A-01S or 1-SI-11-01S by unbolting the pipe and examining them from the inner-diameter. Are there any plans to unbolt either of these fixtures in future inspection periods? | ||
Discuss whether alternative methods or advanced technologies could be employed to maximize ASME Code coverage.Fully clarify, in a table, the wave modality and insonification angles used for all UT examinations | State the material of construction of the piping, valves, elbows, flange, and tees. Identify the dissimilar metal welds in Table I of RR ISIR-41, if any. | ||
The misidentification of the welds can result in delays in finishing the safety evaluation if it is not discovered in a timely fashion. Please review the inspection categories for these welds and confirm that all of the welds as shown in Table I of ISIR-42 are properly identified as per ASME Code Case N-716. [ASME Code Case N-716 has not been approved for use in RG-1.147, Revision 15. Licensees base their RI-ISI inspection sample size and examination methodology on Table I of ASME Code Case N-716.]Discuss whether additional or alternative welds could have been examined to augment the reduced volumetric coverage resulting from the limited examinations of the subject welds.Identify the system(s), and nominal pipe diameters or components for welds 2-SI-569-49S, 2-SI-569-53S, and 2-SI-569-54S. | to AEP-NRC-2012-2 Page 8 I&M Response to NRC Item 8 The Requested Systems, Nominal Pipe Sizes, and materials are provided in the table below. | ||
State the material of construction of the piping, valves, elbows, flange, welds, and tees.Identify the dissimilar metal welds in Table I of RR-42, if any.Photographs were provided for welds 2-RC-22-24, 2-RC-23-12, and 2-RC-24-09; however, these photographs do not identify which welds in the images correspond to the welds in question. | Component ID System Nominal Pipe Size Material (NPS) 1-CTS-2-18F Containment Spray 6.0 SS Type 304 1-SI-2-42S Safety Injection 12.0 SS Type 316 1-SI-24-06F Safety Injection 8.0 SS Type 316 1-SI-30-08F Safety Injection 10.0 SS Type 316 1 -SI-11A-01S Safety Injection 2.5 SS Type 304 1-SI-11-01S Safety Injection 2.5 SS Type 304 1-SI-11-05F Safety Injection 4.0 SS Type 304 1-SI-74-01F Safety Injection 4.0 SS Type 316 2-SI-42-01S Safety Injection 2.5 SS Type 304 2-SI-42-03F Safety Injection 4.0 SS Type 304 The image labeled 1-SI-152N was intended as an aid to location orientation for the pipe to tee weld (1-SI-24-06F). A new image is provided, in the Supporting Documentation section of RR ISIR-41, which clearly identifies the location of 1-SI-24-06F on the image. For reference, 1-SI-1 52N is the label for the check valve in the image. | ||
Please identify which welds in the photographs correspond to welds 2-RC-22-24, 2-RC-23-12, and 2-RC-24-09. | There are no plans to disassemble any portion of the piping system to examine 1-SI-1i1A-01S or 1-SI-11-01S from the inner diameter. | ||
I&M Response to NRC Item 9 Each component has detailed and specific descriptions of each limitation in the supporting documentation. | There are no dissimilar metal welds contained in RR-ISIR-41. | ||
RR ISIR-42 requests relief from the requirement for 100% volumetric examination coverage. | NRC Item 9 - RR ISIR-42 ASME Code. Section Xl. Examination Cateqorv R-A. Items R1111. | ||
Twenty-one of the twenty-three components have only one side of the austenitic weld accessible, and therefore only half of the coverage can be credited, which demonstrates impracticality. | R1.16, and R.120 Submit detailed and specific information to support the bases for limited volumetric coverage in ASME Code, Section XI, Examination Category R-A piping welds, and therefore, demonstrate impracticality. | ||
Component IDs 2-SI-57-19 and 2-SI-57-22 were further limited by bevels adjacent to the weld toes. The remaining component IDs have interferences created by either a permanently installed structural pipe restraint (2-SI-56-10) or a bevel at the weld toe (1-RC-8-02S) which demonstrates impracticality. | As applicable, describe NDE equipment (UT scanning apparatus). Discuss whether alternative methods or advanced technologies could be employed to maximize ASME Code coverage. | ||
Each component has specific descriptions of each limitation in the column titled "Remarks" in Table 1 of ISIR-42. Additional detail is also provided in the Supporting Documentation section of RR ISIR-42 of Reference 1.When these examinations were performed, PA techniques were not yet qualified under the PDI and were therefore not available for use. Additionally, PA cannot overcome certain limitations such as material (CASS), physical obstructions, or prohibitions against crediting more than 50%of examination coverage when only one side of an austenitic weld is accessible. | Fully clarify, in a table, the wave modality and insonification angles used for all UT examinations to AEP-NRC-2012-2 Page 9 Confirm whether the examinations listed for all ASME Code, Section Xl, Examination Category R-A welds were conducted in accordance with the performance demonstration requirements of ASME Code, Section XI, Appendix VIII. | ||
Radiography techniques have not been demonstrated as an equivalent volumetric technique to PDI qualified | The NRC staff has had recent difficulties with risk-informed relief requests in that multiple licensees have misidentified the inspection categories for welds in several relief requests. The misidentification of the welds can result in delays in finishing the safety evaluation if it is not discovered in a timely fashion. Please review the inspection categories for these welds and confirm that all of the welds as shown in Table I of ISIR-42 are properly identified as per ASME Code Case N-716. [ASME Code Case N-716 has not been approved for use in RG-1.147, Revision 15. Licensees base their RI-ISI inspection sample size and examination methodology on Table I of ASME Code Case N-716.] | ||
The size, shape, and proximity of obstructions are described in the NDE datasheets for each component. | Discuss whether additional or alternative welds could have been examined to augment the reduced volumetric coverage resulting from the limited examinations of the subject welds. | ||
At the time of the examinations, no advanced ultrasonic or radiographic techniques were qualified for use;therefore, no alternative examinations were explored.All wave modes and insonification angles were previously identified in the component NDE Datasheet, which were provided in the Supporting Documentation section of RR ISIR-42 by Reference | Identify the system(s), and nominal pipe diameters or components for welds 2-SI-569-49S, 2-SI-569-53S, and 2-SI-569-54S. | ||
State the material of construction of the piping, valves, elbows, flange, welds, and tees. | |||
Component ID Insonification Angle(s) Wave Mode*1 -CS-96-60F | Identify the dissimilar metal welds in Table I of RR-42, if any. | ||
Aspects evaluated for weld selection included, but was not limited to, access, previous history, radiological exposure, industry operating experience, and system operation. | Photographs were provided for welds 2-RC-22-24, 2-RC-23-12, and 2-RC-24-09; however, these photographs do not identify which welds in the images correspond to the welds in question. Please identify which welds in the photographs correspond to welds 2-RC-22-24, 2-RC-23-12, and 2-RC-24-09. | ||
When confronted with a limitation on a weld, an evaluation is made to determine if a replacement weld can be substituted for the weld experiencing a limitation. | I&M Response to NRC Item 9 Each component has detailed and specific descriptions of each limitation in the supporting documentation. RR ISIR-42 requests relief from the requirement for 100% volumetric examination coverage. Twenty-one of the twenty-three components have only one side of the austenitic weld accessible, and therefore only half of the coverage can be credited, which demonstrates impracticality. Component IDs 2-SI-57-19 and 2-SI-57-22 were further limited by bevels adjacent to the weld toes. The remaining component IDs have interferences created by either a permanently installed structural pipe restraint (2-SI-56-10) or a bevel at the weld toe (1-RC-8-02S) which demonstrates impracticality. Each component has specific descriptions of each limitation in the column titled "Remarks" in Table 1 of ISIR-42. Additional detail is also provided in the Supporting Documentation section of RR ISIR-42 of Reference 1. | ||
There are many considerations that must be evaluated before a weld can be substituted, such as whether the substituted weld is subject to the same degradation mechanism, whether additional coverage can be achieved on the substitute weld, whether additional resources such as weld prep, insulation removal and scaffolding are required. | When these examinations were performed, PA techniques were not yet qualified under the PDI and were therefore not available for use. Additionally, PA cannot overcome certain limitations such as material (CASS), physical obstructions, or prohibitions against crediting more than 50% | ||
Additionally, welds with similar or more limiting limitations are not substituted. | of examination coverage when only one side of an austenitic weld is accessible. Radiography techniques have not been demonstrated as an equivalent volumetric technique to PDI qualified to AEP-NRC-2012-2 Page 10 examinations and would be a significant hardship on resources due to the required evacuation of work areas for extended periods of time. | ||
Therefore, typically the weld originally selected is the best fit. | The NDE equipment used was standard ultrasonic scopes, transducers, and wedges that were authorized for use by the PDI at the time of the examinations. The size, shape, and proximity of obstructions are described in the NDE datasheets for each component. At the time of the examinations, no advanced ultrasonic or radiographic techniques were qualified for use; therefore, no alternative examinations were explored. | ||
All wave modes and insonification angles were previously identified in the component NDE Datasheet, which were provided in the Supporting Documentation section of RR ISIR-42 by Reference 1. The table below provides a summary of the wave modes and insonification angles for each component. | |||
Additionally, impact to personnel and equipment safety is also considered. | Component ID Insonification Angle(s) Wave Mode* | ||
Based on these considerations, no additional or alternative welds were examined.The nominal pipe diameter for 2-SI-569-49S, 2-SI-569-53S, and 2-SI-569-54S is 1.5" and these welds are located in the Safety Injection system.All materials in RR ISIR-42 are Stainless Steel Type 304 or 316. There are no dissimilar metal welds contained in RR ISIR-42.The photographs provided for 2-RC-22-24, 2-RC-23-12, and 2-RC-24-09 were included for illustrative purposes only and not intended as the basis for the limitations. | 1-CS-96-60F 00 L, 45 0 S, 60°S 1-SI-29-19S 0°L, 45°S, 60°RL 1-SI-29-20S 0°L, 450 S, 60°RL 1-SI-29-23S 0°L, 450 S, 60°RL 1-SI-31-21S 0°L, 450 S, 60°RL 2-SI-57-19 0°L, 45 0 S, 600S, 60°RL 2-SI-57-21 0°L, 45 0 S, 600 S, 60°RL 2-SI-56-18 0°L, 45 0 S, 60 0S, 600 L 1-SI-548-45S 0°L, 3 0 °S, 450 S, 600 S, 1-RH-30-06F 45°S, 60 0 S, 60°RL 1-RC-8-02S 45S, 600 S 1-SI-29-26F 45 0 S, 60 0 S, 60°RL 1-SI-33-26F 450S, 60 0 S, 60°RL 2-RC-22-24 0°L, 45 0S, 600 L, 700S to AEP-NRC-2012-2 Page 11 Component ID Insonification Angle(s) Wave Mode* | ||
It was thought that a visual perspective would be helpful in understanding the configuration. | 2-RC-23-12 0°L, 45°S, 600 L, 70°S 2-RC-24-09 0°L, 45 0S, 600 L, 700S 2-SI-569-49S 450S 2-SI-569-53S 45 0 S 2-SI-569-54S 450S 2-SI-57-22 0°L, 450S, 600S, 60°RL 2-SI-56-10 0°L, 450S, 600S, 600L 2-SI-78-01 450S, 600S, 60-L 2-SI-56-22 0°L, 450S, 600S, 60°L | ||
Annotated drawings have been added to the Supporting Documentation section of RR ISIR-42 for 2-RC-22-24, 2-RC-23-12, and 2-RC-24-09 with the applicable weld locations identified. | *L= Longitudinal, S= Shear and RL = Refracted Longitudinal As previously stated in Sections 2, 3, 4, and 6 of RR ISIR-42 by Reference 1, the examinations were performed using qualified Appendix VIII examinations (as modified by the PDI and 10 CFR 50.55a). | ||
Enclosure 2 to AEP-NRC-2012-2 REVISED INSERVICE INSPECTION RELIEF REQUESTS ISIR-33 THROUGH ISIR-42 | All of the welds in Table 1 of RR ISIR-42 have been verified to be in the correct inspection category of ASME Code Case N-716. | ||
The weld selection process for CNP was accomplished during the development of the Risk-Informed Inservice Inspection (RI-ISI) program using an expert panel of operations, radiation protection, scaffold/insulation, system engineering, NDE, and ISI personnel. Aspects evaluated for weld selection included, but was not limited to, access, previous history, radiological exposure, industry operating experience, and system operation. | |||
When confronted with a limitation on a weld, an evaluation is made to determine if a replacement weld can be substituted for the weld experiencing a limitation. There are many considerations that must be evaluated before a weld can be substituted, such as whether the substituted weld is subject to the same degradation mechanism, whether additional coverage can be achieved on the substitute weld, whether additional resources such as weld prep, insulation removal and scaffolding are required. Additionally, welds with similar or more limiting limitations are not substituted. Therefore, typically the weld originally selected is the best fit. | |||
to AEP-NRC-2012-2 Page 12 The process of identifying additional welds for examination during a refueling outage to accommodate a potential increase in weld coverage employs the risk-informed approach and its limitations. Additionally, impact to personnel and equipment safety is also considered. Based on these considerations, no additional or alternative welds were examined. | |||
The nominal pipe diameter for 2-SI-569-49S, 2-SI-569-53S, and 2-SI-569-54S is 1.5" and these welds are located in the Safety Injection system. | |||
All materials in RR ISIR-42 are Stainless Steel Type 304 or 316. There are no dissimilar metal welds contained in RR ISIR-42. | |||
The photographs provided for 2-RC-22-24, 2-RC-23-12, and 2-RC-24-09 were included for illustrative purposes only and not intended as the basis for the limitations. It was thought that a visual perspective would be helpful in understanding the configuration. Annotated drawings have been added to the Supporting Documentation section of RR ISIR-42 for 2-RC-22-24, 2-RC-23-12, and 2-RC-24-09 with the applicable weld locations identified. | |||
Enclosure 2 to AEP-NRC-2012-2 REVISED INSERVICE INSPECTION RELIEF REQUESTS ISIR-33 THROUGH ISIR-42 to AEP-NRC-2012-2 Page 1 RELIEF REQUEST ISIR-33 EXAMINATION CATEGORY B-A PRESSURE RETAINING WELDS IN REACTOR VESSEL and EXAMINATION CATEGORY B-D FULL PENETRATION WELDS OF NOZZLES IN VESSELS - INSPECTION PROGRAM B (Reactor Vessel only) to AEP-NRC-2012-2 Page 2 RELIEF REQUEST ISIR-33 Relief Request In Accordance with 10 CFR 50.55a(g)(5)(iii) | |||
Inservice Inspection Impracticality | Inservice Inspection Impracticality | ||
: 1. ASME Code Components Affected ASME Code Class: Examination Category: | : 1. ASME Code Components Affected ASME Code Class: Code Class 1 Examination Category: B-A, Pressure Retaining Welds in Reactor Vessel B-D, Full Penetration Welds of Nozzles in Vessels - Inspection Program B (Reactor Vessel only) | ||
Listed in Table 1 2. Applicable Code Addition and Addenda ASME Section Xl, 1989 Edition, No addenda 3. Applicable Code Requirement ASME Section XI, 1989 Edition, Examination Category B-A requires volumetric examination of 100 percent of the weld volume as defined in ASME Section XI Table IWB-2500-1 and shown in Figures IWB-2500-1, IWB-2500-2 and IWB- 2500-3. The alternative requirements of ASME Section Xl, Code Case N-460, approved for use in Regulatory Guide 1 .147 Rev. 15, allows credit for essentially 100 percent coverage of the weld provided greater than 90 percent of the required volume has been examined.4. Impracticality of Compliance Pursuant to 10 CFR 50.55a(g)(5)(iii), relief is requested from the essentially 100 percent volumetric examination coverage requirement for the subject Welds. Due to the design of the reactor vessel, geometric configuration and permanent obstructions limit the volumetric examination coverage of the subject welds.During the second 10-year reactor pressure vessel examination, the best available technology was utilized in performing the automated ultrasonic examination. | Item Numbers: B 1.11, Shell Welds - Circumferential B1.12, Shell Welds - Longitudinal B1 .21, Head Welds - Circumferential B1.22, Head Welds - Meridional B3.90, Reactor Vessel - Nozzle to Vessel Welds Component Identification: Listed in Table 1 | ||
The examinations were performed with equipment, procedures and personnel qualified in accordance with the requirements of ASME Section Xl, Appendix VIII, 1995 Edition thru 1996 Addenda as modified by the Performance Demonstration Initiative (PDI) program. | : 2. Applicable Code Addition and Addenda ASME Section Xl, 1989 Edition, No addenda | ||
This is impractical due to the cost, additional radiation exposure and impact to plant equipment. | ===3. Applicable Code Requirement=== | ||
: 6. Proposed Alternative and Basis for Use The subject welds received a volumetric examination on the accessible portions of the subject welds to the maximum extent practical given the limitations caused by the geometric configuration and permanent obstructions. | ASME Section XI, 1989 Edition, Examination Category B-A requires volumetric examination of 100 percent of the weld volume as defined in ASME Section XI Table IWB-2500-1 and shown in Figures IWB-2500-1, IWB-2500-2 and IWB- 2500-3. The alternative requirements of ASME Section Xl, Code Case N-460, approved for use in Regulatory Guide 1 .147 Rev. 15, allows credit for essentially 100 percent coverage of the weld provided greater than 90 percent of the required volume has been examined. | ||
Additionally, a visual examination (VT-2) is performed at the end of each refueling outage during the system leakage tests as required by Section Xl, IWB-2500-1, Category B-P.Based upon the examination volumes that were obtained with acceptable results along with the visual (VT-2) examination performed each refueling outage, it is reasonable to conclude that service induced degradation would be detected. | : 4. Impracticality of Compliance Pursuant to 10 CFR 50.55a(g)(5)(iii), relief is requested from the essentially 100 percent volumetric examination coverage requirement for the subject Welds. Due to the design of the reactor vessel, geometric configuration and permanent obstructions limit the volumetric examination coverage of the subject welds. | ||
Therefore, these proposed alternatives provide an acceptable level of quality and safety by providing reasonable assurance of structural integrity of the subject welds.7. Period for Which Relief is Requested The relief is requested for the Third 10-year inspection interval for D.C. Cook Units 1 and 2, which began on July 1, 1996 and ended April 9, 2010 at the conclusion of the Unit 1 Cycle 23 Refueling Outage. Significant long-term outages (greater than six months) occurred multiple times during the interval and the interval was extended as allowed by IWA-2430(e) and by IWA-2430(d) to accommodate interva.l planning and scheduling. | During the second 10-year reactor pressure vessel examination, the best available technology was utilized in performing the automated ultrasonic examination. The examinations were performed with equipment, procedures and personnel qualified in accordance with the requirements of ASME Section Xl, Appendix VIII, 1995 Edition thru 1996 Addenda as modified by the Performance Demonstration Initiative (PDI) program. | ||
to AEP-NRC-2012-2 Page 3 Several interferences and vessel geometries prevent full volumetric examination coverage, including the 58 permanent incore instrument nozzles penetrating the bottom head and six core support lugs permanently attached to the vessel interior limiting the access to the lower head welds. The close proximity of the inlet nozzle and outlet nozzle boss limits the ultrasonic scanning of the upper shell longitudinal seam welds. The flange to vessel configuration, specimen slots, and keyways also hinder access. These noted obstructions prevent achieving the essentially.100 percent volumetric examination coverage required by code. Also, Nozzle to Vessel geometry, vessel saddle effect, and adjacent outlet nozzle protrusion limited access for achieving 100 percent volumetric examination coverage for the Nozzle to Vessel welds. | |||
The limitations 1 1-RPV-A Shell to Flange B1.30 84.44NY are due to flange configuration, specimen slots, and keyways at 0, 90, 180, and 270 degrees. No recordable indications detected.The completed examination was limited to 82.60%Lower Shell to Bottom coverage due to the configuration. | The limitations and the actual examination coverage attained for each weld for which relief is requested are noted in the Table 1. | ||
The limitations Head are due to six core support lugs. No recordable indications detected.The completed examination was limited to 38.4%1 1-RPV-E Dollar Plate B1.21 38.4/Y coverage due to the configuration. | : 5. Burden Caused by Compliance To increase examination coverage on the subject welds requires a significant design modification or replacement of components with a different design to eliminate the noted obstructions. This is impractical due to the cost, additional radiation exposure and impact to plant equipment. | ||
The limitation is due to the bottom mounted | : 6. Proposed Alternative and Basis for Use The subject welds received a volumetric examination on the accessible portions of the subject welds to the maximum extent practical given the limitations caused by the geometric configuration and permanent obstructions. Additionally, a visual examination (VT-2) is performed at the end of each refueling outage during the system leakage tests as required by Section Xl, IWB-2500-1, Category B-P. | ||
Based upon the examination volumes that were obtained with acceptable results along with the visual (VT-2) examination performed each refueling outage, it is reasonable to conclude that service induced degradation would be detected. Therefore, these proposed alternatives provide an acceptable level of quality and safety by providing reasonable assurance of structural integrity of the subject welds. | |||
: 7. Period for Which Relief is Requested The relief is requested for the Third 10-year inspection interval for D.C. Cook Units 1 and 2, which began on July 1, 1996 and ended April 9, 2010 at the conclusion of the Unit 1 Cycle 23 Refueling Outage. Significant long-term outages (greater than six months) occurred multiple times during the interval and the interval was extended as allowed by IWA-2430(e) and by IWA-2430(d) to accommodate interva.l planning and scheduling. | |||
The limitation Degrees is due to the core support lug. No recordable indications detected.Lower Shell The completed examination was limited to 78.29%1 1-RPV-VC2 Longitudinal at 180 B1.12 78.29/Y coverage due to the configuration. | to AEP-NRC-2012-2 Page 4 Table 1 to Relief Request ISIR-33 Ultrasonic CNP Item Examination Cvrg eak Weld Description Number Coverage Remarks Unit Component ID. Attained (%)/ | ||
The limitation Degrees is due to the core support lug. No recordable indications detected.Lower Shell The completed examination was limited to 78.29%1 1-RPV-VC3 Longitudinal at 300 B1.12 78.29/Y coverage due to the configuration. | PDI (Y/N) | ||
The limitation Degrees is due to the core support lug. No recordable I I I indications detected. | The completed examination was limited to 84.4% | ||
coverage due to the configuration. The limitations 1 1-RPV-A Shell to Flange B1.30 84.44NY are due to flange configuration, specimen slots, and keyways at 0, 90, 180, and 270 degrees. No recordable indications detected. | |||
The limitation Degrees is due to bottom mounted instrumentation penetrations. | The completed examination was limited to 82.60% | ||
No recordable indications detected.Lower Head The completed examination was limited to 73.26%1 1-LHM-02 Meridional at 90 B1.22 73.26/Y coverage due to the configuration. | Lower Shell to Bottom coverage due to the configuration. The limitations Head are due to six core support lugs. No recordable indications detected. | ||
The limitation Degrees is due to bottom mounted instrumentation penetrations. | The completed examination was limited to 38.4% | ||
No recordable indications detected.Lower Head The completed examination was limited to 88.1%1 1-LHM-05 Meridional at 270 B1.22 88.11Y coverage due to the configuration. | 1 1-RPV-E Dollar Plate B1.21 38.4/Y coverage due to the configuration. The limitation is due to the penetrations. bottom mounted No recordable indications instrument detected. | ||
The limitation Degrees is due to bottom mounted instrumentation penetrations. | Lower Shell The completed examination was limited to 78.29% | ||
No recordable indications detected.Lower Head The completed examination was limited to 74.5%1 1-LHM-06 Meridional at 330 B1.22 74.5/Y coverage due to the configuration. | 1 1-RPV-VC1 Longitudinal at 60 B1.12 78.29/Y coverage due to the configuration. The limitation Degrees is due to the core support lug. No recordable indications detected. | ||
The limitation Degrees is due to bottom mounted instrumentation penetrations. | Lower Shell The completed examination was limited to 78.29% | ||
No recordable indications detected.The completed examination was limited to 71.08%coverage due to the configuration. | 1 1-RPV-VC2 Longitudinal at 180 B1.12 78.29/Y coverage due to the configuration. The limitation Degrees is due to the core support lug. No recordable indications detected. | ||
The limitation 1-N3B Outlet Nozzle to Shell B3.90 71.08N is | Lower Shell The completed examination was limited to 78.29% | ||
Two subsurface indications were detected and evaluated as acceptable to IWB-3512-1. | 1 1-RPV-VC3 Longitudinal at 300 B1.12 78.29/Y coverage due to the configuration. The limitation Degrees is due to the core support lug. No recordable I I I indications detected. | ||
The completed examination was limited to 71.08%coverage due to the configuration. | to AEP-NRC-2012-2 Page 5 Ultrasonic Unit Component ID Weld Description Examination Number Coverage Remarks Attained (%)/ | ||
The limitation 1-N4B Outlet Nozzle to Shell B3.90 71.08N is due to nozzle geometry, vessel saddle effect, at 158 Degrees and adjacent outlet nozzle protrusion. | PDI (Y/N) | ||
One subsurface indication was detected and evaluated as acceptable to IWB-3512-1. | Lower Head The completed examination was limited to 79.0% | ||
1 1-LHM-01 Meridional at 30 B1.22 79.0/ coverage due to the configuration. The limitation Degrees is due to bottom mounted instrumentation penetrations. No recordable indications detected. | |||
The limitation 1-N1B Outlet Nozzle to Shell at B3.90 71.08NY is due to nozzle geometry, vessel saddle effect 202 Degrees and adjacent outlet nozzle protrusion. | Lower Head The completed examination was limited to 73.26% | ||
Six subsurface indications were detected and evaluated as acceptable to IWB-3512-1. | 1 1-LHM-02 Meridional at 90 B1.22 73.26/Y coverage due to the configuration. The limitation Degrees is due to bottom mounted instrumentation penetrations. No recordable indications detected. | ||
The completed examination was limited to 71.08%coverage due to the configuration. | Lower Head The completed examination was limited to 88.1% | ||
The limitation 1-N2B Outlet Nozzle to Shell at B3.90 71.08/Y is due to nozzle geometry, vessel saddle effect 338 Degrees and adjacent outlet nozzle protrusion. | 1 1-LHM-05 Meridional at 270 B1.22 88.11Y coverage due to the configuration. The limitation Degrees is due to bottom mounted instrumentation penetrations. No recordable indications detected. | ||
Eight subsurface indications were detected and evaluated as acceptable to IWB-3512-1. | Lower Head The completed examination was limited to 74.5% | ||
1 1-LHM-06 Meridional at 330 B1.22 74.5/Y coverage due to the configuration. The limitation Degrees is due to bottom mounted instrumentation penetrations. No recordable indications detected. | |||
The completed examination was limited to 71.08% | |||
coverage due to the configuration. The limitation 1-N3B Outlet Nozzle to Shell B3.90 71.08N is at 22 Degrees anddueadjacent to nozzleoutlet geometry, nozzlevessel saddle effect, protrusion. Two subsurface indications were detected and evaluated as acceptable to IWB-3512-1. | |||
The completed examination was limited to 71.08% | |||
coverage due to the configuration. The limitation 1-N4B Outlet Nozzle to Shell B3.90 71.08N is due to nozzle geometry, vessel saddle effect, at 158 Degrees and adjacent outlet nozzle protrusion. One subsurface indication was detected and evaluated as acceptable to IWB-3512-1. | |||
to AEP-NRC-2012-2 Page 6 Ultrasonic Examination CNP Component ID Weld Description Item Coverage Remarks Unit Number Attained | |||
(%)I PDI (Y/N) | |||
The completed examination was limited to 71.08% | |||
coverage due to the configuration. The limitation 1-N1B Outlet Nozzle to Shell at B3.90 71.08NY is due to nozzle geometry, vessel saddle effect 202 Degrees and adjacent outlet nozzle protrusion. Six subsurface indications were detected and evaluated as acceptable to IWB-3512-1. | |||
The completed examination was limited to 71.08% | |||
coverage due to the configuration. The limitation 1-N2B Outlet Nozzle to Shell at B3.90 71.08/Y is due to nozzle geometry, vessel saddle effect 338 Degrees and adjacent outlet nozzle protrusion. Eight subsurface indications were detected and evaluated as acceptable to IWB-3512-1. | |||
to AEP-NRC-2012-2 Page 7 RELIEF REQUEST ISIR-33 EXAMINATION CATEGORY B-A PRESSURE RETAINING WELDS IN REACTOR VESSEL And EXAMINATION CATEGORY B-D FULL PENETRATION WELDS OF NOZZLES IN VESSELS - INSPECTION PROGRAM B (Reactor Vessel only) | |||
SUPPORTING DOCUMENTATION IS PROVIDED BY I&M LETTER DATED APRIL 8, 2011 ADAMS ACCESSION NO. ML11110A042 to AEP-NRC-2012-2 Page 8 RELIEF REQUEST ISIR-34 EXAMINATION CATEGORY B-B PRESSURE RETAINING WELDS IN VESSELS OTHER THAN REACTOR VESSELS to AEP-NRC-2012-2 Page 9 RELIEF REQUEST ISIR-34 Relief Request In Accordance with 10 CFR 50.55a(g)(5)(iii) | |||
Inservice Inspection Impracticality | Inservice Inspection Impracticality | ||
: 1. ASME Code Components Affected ASME Code Class: Code Class 1 Examination Category: | : 1. ASME Code Components Affected ASME Code Class: Code Class 1 Examination Category: B-B, Pressure Retaining Welds in Vessels Other Than Reactor Vessels Item Numbers: B2.40, Steam Generators (Primary Side) - Tubesheet to Head Component Identification: Listed in Table 1 | ||
B-B, Pressure Retaining Welds in Vessels Other Than Reactor Vessels Item Numbers: B2.40, Steam Generators (Primary Side) -Tubesheet to Head Component Identification: | |||
Listed in Table 1 2. Applicable Code Edition and Addenda ASME Section Xl, 1989 Edition, No addenda 3. Applicable Code Requirement ASME Section XI, 1989 Edition, Examination Category B-B requires volumetric examination of 100 percent of the weld volume as defined in Table IWB-2500-1 and shown in Figures IWB-2500-1 and IWB-2500-6. | ===2. Applicable Code Edition and Addenda=== | ||
The alternative requirements of ASME Section XI, Code Case N-460, approved for use in Regulatory Guide 1.147, Revision 15, allows credit for essentially 100 percent coverage of the welds provided greater than 90 percent of the required volume has been examined.4. Impracticality of Compliance Pursuant to 10 CFR 50.55a(g)(5)(iii), relief is requested from the essentially 100 percent volumetric examination coverage requirement for the subject welds due to the geometric configuration and permanent obstructions which limit the volumetric examination coverage of the subject welds.The Steam Generator Tubesheet to Head Weld (2-24-01) was limited to 72% coverage due to the configuration. | ASME Section Xl, 1989 Edition, No addenda | ||
Examination coverage was limited due to the proximity of welded pads, nozzles, adjacent piping, hand-hole openings, permanent support brackets, and permanent electrical conduits.These noted obstructions prevent achieving the essentially 100 percent volume examination coverage required by code.The limitations and the actual examination coverage attained for each weld for which relief is requested are noted in Table 1. | |||
===3. Applicable Code Requirement=== | |||
Additionally, to increase examination coverage on the subject weld would require a significant design modification or replacement of components with a different design to eliminate the noted obstructions. | ASME Section XI, 1989 Edition, Examination Category B-B requires volumetric examination of 100 percent of the weld volume as defined in Table IWB-2500-1 and shown in Figures IWB-2500-1 and IWB-2500-6. The alternative requirements of ASME Section XI, Code Case N-460, approved for use in Regulatory Guide 1.147, Revision 15, allows credit for essentially 100 percent coverage of the welds provided greater than 90 percent of the required volume has been examined. | ||
This is impractical due to the cost, additional radiation exposure, and impact to plant equipment. | : 4. Impracticality of Compliance Pursuant to 10 CFR 50.55a(g)(5)(iii), relief is requested from the essentially 100 percent volumetric examination coverage requirement for the subject welds due to the geometric configuration and permanent obstructions which limit the volumetric examination coverage of the subject welds. | ||
: 6. Proposed Alternative and Basis for Use The subject welds received a volumetric examination on the accessible portions of the subject welds to the maximum extent practical given the limitations caused by the geometric configuration and permanent obstructions. | The Steam Generator Tubesheet to Head Weld (2-24-01) was limited to 72% coverage due to the configuration. Examination coverage was limited due to the proximity of welded pads, nozzles, adjacent piping, hand-hole openings, permanent support brackets, and permanent electrical conduits. | ||
Additionally, a visual examination (VT-2) is performed at the end of each refueling outage during the system leakage tests as required by Section Xl, IWB-2500-1, Category B-P.Based upon the examination volumes that were obtained with acceptable results, along with the visual (VT-2) examination performed each refueling outage, it is reasonable to conclude that service induced degradation would be detected. | These noted obstructions prevent achieving the essentially 100 percent volume examination coverage required by code. | ||
Therefore, these proposed alternatives provide an acceptable level of quality and safety by providing reasonable assurance of structural integrity of the subject welds.7. Period for Which Relief is Requested The relief is requested for the Third 10-year inspection interval for Donald C. Cook Nuclear Plant Units 1 and 2, which began on July 1, 1996, and ended April 9, 2010, at the conclusion of the Unit 1 Cycle 23 Refueling Outage. Significant long-term outages (greater than six months) occurred multiple times during the interval and the interval was extended as allowed by IWA-2430(e) and by IWA-2430(d) to accommodate interval planning and scheduling. | The limitations and the actual examination coverage attained for each weld for which relief is requested are noted in Table 1. | ||
to AEP-NRC-2012-2 Page 10 | |||
Examination o72.0/N (per coverage was limited due to the proximity of welded | : 5. Burden Caused by Compliance To increase the examination coverage for STM-24-01 requires removal and reinstallation of insulation support ring mounting pads by cutting the mounting pad welds and then reinstalling the mounting pads by welding following completion of the examination. Additionally, to increase examination coverage on the subject weld would require a significant design modification or replacement of components with a different design to eliminate the noted obstructions. This is impractical due to the cost, additional radiation exposure, and impact to plant equipment. | ||
One subsurface indication was detected and evaluated as acceptable to IWB-3512-1. | : 6. Proposed Alternative and Basis for Use The subject welds received a volumetric examination on the accessible portions of the subject welds to the maximum extent practical given the limitations caused by the geometric configuration and permanent obstructions. Additionally, a visual examination (VT-2) is performed at the end of each refueling outage during the system leakage tests as required by Section Xl, IWB-2500-1, Category B-P. | ||
Based upon the examination volumes that were obtained with acceptable results, along with the visual (VT-2) examination performed each refueling outage, it is reasonable to conclude that service induced degradation would be detected. Therefore, these proposed alternatives provide an acceptable level of quality and safety by providing reasonable assurance of structural integrity of the subject welds. | |||
: 7. Period for Which Relief is Requested The relief is requested for the Third 10-year inspection interval for Donald C. Cook Nuclear Plant Units 1 and 2, which began on July 1, 1996, and ended April 9, 2010, at the conclusion of the Unit 1 Cycle 23 Refueling Outage. Significant long-term outages (greater than six months) occurred multiple times during the interval and the interval was extended as allowed by IWA-2430(e) and by IWA-2430(d) to accommodate interval planning and scheduling. | |||
to AEP-NRC-2012-2 Page 11 Table 1 to Relief Request ISIR-34 Ultrasonic Examination CNP Component ID Weld Description Item Coverage Unit Number Attained | |||
(%)I PDI (Y/N) | |||
The completed examination was limited to 72% | |||
coverage due to the configuration. Examination o72.0/N (per coverage was limited due to the proximity of welded STM- Shell 2 Tubesheet to 1Lower B2.40 7 4per pads, nozzles, adjacent piping, hand-hole openings, Section V) permanent support brackets, and permanent electrical conduits. One subsurface indication was detected and evaluated as acceptable to IWB-3512-1. | |||
to AEP-NRC-2012-2 Page 12 RELIEF REQUEST ISIR-34 EXAMINATION CATEGORY B-B PRESSURE RETAINING WELDS IN VESSELS OTHER THAN REACTOR VESSELS SUPPORTING DOCUMENTATION IS PROVIDED BY I&M LETTER DATED APRIL 8, 2011 ADAMS ACCESSION NO. ML11111OA042 to AEP-NRC-2012-2 Page 13 RELIEF REQUEST ISIR-35 EXAMINATION CATEGORY B-D FULL PENETRATION WELDS OF NOZZLES IN VESSELS - INSPECTION PROGRAM B to AEP-NRC-2012-2 Page 14 RELIEF REQUEST ISIR-35 Relief Request In Accordance with 10 CFR 50.55a(g)(5)(iii) | |||
Inservice Inspection Impracticality | Inservice Inspection Impracticality | ||
: 1. ASME Code Components Affected ASME Code Class: Code Class 1 Examination Category: | : 1. ASME Code Components Affected ASME Code Class: Code Class 1 Examination Category: B-D, Full Penetration Welds of Nozzles in Vessels - Inspection Program B Item Numbers: B3. 110, Pressurizer, Nozzle to Vessel Welds B3.140, Steam Generators (Primary Side) - Nozzle Inside Radius Section (IRS) | ||
B-D, Full Penetration Welds of Nozzles in Vessels -Inspection Program B Item Numbers: B3. 110, Pressurizer, Nozzle to Vessel Welds B3.140, Steam Generators (Primary Side) -Nozzle Inside Radius Section (IRS)Component Identification: | Component Identification: Listed in Table 1 | ||
Listed in Table 1 2. Applicable Code Edition and Addenda ASME Section Xl, 1989 Edition, No addenda 3. Applicable Code Requirement ASME Section Xl, 1989 Edition, Examination Category B-D requires volumetric examination of 100 percent of the weld volume as defined in Table IWB-2500-1 and shown in Figures IWB-2500-7(a) thru (d) as applicable. | |||
The alternative requirements of ASME Section Xl, Code Case N-460, approved for use in Regulatory Guide 1.147, Revision 15, allows credit for essentially 100 percent coverage of the welds provided greater than 90 percent of the required volume has been examined.4. Impracticality of Compliance Pursuant to 10 CFR 50.55a(g)(5)(iii), relief is requested from the essentially 100 percent volumetric examination coverage requirement for the subject welds due to the geometric configuration and permanent obstructions which limit the volumetric examination coverage of the subject welds.The Steam Generator Inner Radius examinations (STM-12-1-IRS, STM-12-O-IRS, STM-14-1-IRS and STM-14-0-IRS) were limited to 34.9%, 36.8%, 40.9% and 25% coverage, respectively. | ===2. Applicable Code Edition and Addenda=== | ||
Due to the component geometry, no coverage of the inner radius region can be effectively obtained by scanning from the shell side. No contact could be maintained in the blend radius area.Additionally, the pressurizer Nozzle to Vessel welds (2-RC-26 and 2-RC-27) were each limited to 75% coverage. | ASME Section Xl, 1989 Edition, No addenda | ||
Examination limitations were due to the contour of the weld on the nozzle side, where 50% coverage was achieved for both the 45 and 60 degree axial scans. | |||
===3. Applicable Code Requirement=== | |||
This is impractical due to the cost, additional radiation exposure, and impact to plant equipment. | ASME Section Xl, 1989 Edition, Examination Category B-D requires volumetric examination of 100 percent of the weld volume as defined in Table IWB-2500-1 and shown in Figures IWB-2500-7(a) thru (d) as applicable. The alternative requirements of ASME Section Xl, Code Case N-460, approved for use in Regulatory Guide 1.147, Revision 15, allows credit for essentially 100 percent coverage of the welds provided greater than 90 percent of the required volume has been examined. | ||
: 6. Proposed Alternative and Basis for Use The subject welds received a volumetric examination on the accessible portions of the subject welds to the maximum extent practical. | : 4. Impracticality of Compliance Pursuant to 10 CFR 50.55a(g)(5)(iii), relief is requested from the essentially 100 percent volumetric examination coverage requirement for the subject welds due to the geometric configuration and permanent obstructions which limit the volumetric examination coverage of the subject welds. | ||
Additionally, welds 2-RC-26 and 2-RC-27 received a Surface Examination. | The Steam Generator Inner Radius examinations (STM-12-1-IRS, STM-12-O-IRS, STM-14-1-IRS and STM-14-0-IRS) were limited to 34.9%, 36.8%, 40.9% and 25% coverage, respectively. Due to the component geometry, no coverage of the inner radius region can be effectively obtained by scanning from the shell side. No contact could be maintained in the blend radius area. | ||
Further, a visual examination (VT-2) is performed at the end of each refueling outage during the system leakage tests as required by Section Xl, IWB-2500-1, Category B-P.Based upon the examination volumes that were obtained with acceptable results, along with the visual (VT-2) examination performed each refueling outage, it is reasonable to conclude that service induced degradation would be detected. | Additionally, the pressurizer Nozzle to Vessel welds (2-RC-26 and 2-RC-27) were each limited to 75% coverage. Examination limitations were due to the contour of the weld on the nozzle side, where 50% coverage was achieved for both the 45 and 60 degree axial scans. | ||
Therefore, these proposed alternatives provide an acceptable level of quality and safety by providing reasonable assurance of structural integrity of the subject welds.7. Period for Which Relief is Requested The relief is requested for the Third 10-year inspection interval for Donald C. Cook Nuclear Plant Units 1 and 2, which began on July 1, 1996, and ended April 9, 2010, at the conclusion of the Unit 1 Cycle 23 Refueling Outage. Significant long-term outages (greater than six months) occurred multiple times during the interval and the interval was extended as allowed by IWA-2430(e) and by IWA-2430(d) to accommodate interval planning and scheduling. | to AEP-NRC-2012-2 Page 15 These noted obstructions prevent achieving the essentially 100 percent volumetric examination coverage required by code. | ||
The limitations and the actual examination coverage attained for each weld for which relief is requested are noted in Table 1. | |||
Due to the Inlet Nozzle Inside 40.9/N-(per component geometry, no coverage of the inner radius STM-14-1-IRS Radius Section B3.140 Article 4 of region can be effectively obtained by scanning from Section V) the shell side. No contact could be maintained in the blend radius area. No recordable indications detected.The completed examination was limited to 25%coverage due to the configuration. | : 5. Burden Caused by Compliance To increase examination coverage on the subject weld would require a significant design modification or replacement of components with a different design to eliminate the noted obstructions. This is impractical due to the cost, additional radiation exposure, and impact to plant equipment. | ||
Due to the 25.0/N (per component geometry, no coverage of the inner radius IRSTRadOut Secions B3.140 Article 4 of region can be effectively obtained by scanning from | : 6. Proposed Alternative and Basis for Use The subject welds received a volumetric examination on the accessible portions of the subject welds to the maximum extent practical. Additionally, welds 2-RC-26 and 2-RC-27 received a Surface Examination. Further, a visual examination (VT-2) is performed at the end of each refueling outage during the system leakage tests as required by Section Xl, IWB-2500-1, Category B-P. | ||
Due to the 34.9/N (per component geometry, no coverage of the inner radius STM-12-1-IRS Radius Section B3.140 Article 4 of region can be effectively obtained by scanning from Section V) the shell side. No contact could be maintained in the blend radius area. No recordable indications detected. | Based upon the examination volumes that were obtained with acceptable results, along with the visual (VT-2) examination performed each refueling outage, it is reasonable to conclude that service induced degradation would be detected. Therefore, these proposed alternatives provide an acceptable level of quality and safety by providing reasonable assurance of structural integrity of the subject welds. | ||
: 7. Period for Which Relief is Requested The relief is requested for the Third 10-year inspection interval for Donald C. Cook Nuclear Plant Units 1 and 2, which began on July 1, 1996, and ended April 9, 2010, at the conclusion of the Unit 1 Cycle 23 Refueling Outage. Significant long-term outages (greater than six months) occurred multiple times during the interval and the interval was extended as allowed by IWA-2430(e) and by IWA-2430(d) to accommodate interval planning and scheduling. | |||
Due to the 36.8/N (per component geometry, no coverage of the inner radius 1 STMRadiO-ue N ecions B3.140 Article 4 of region can be effectively obtained by scanning from | to AEP-NRC-2012-2 Page 16 Table 1 to Relief Request ISIR-35 Ultrasonic Examination CNP Unit Component ID Weld Description Item Number Coverage Remarks Attained (%)/ | ||
Exam limitations 2 2-RC-26 Upper Head to Relief B3.110 75.0/ (per Article were due to the contour of the weld on the nozzle Nozzle 4 of Section V) side, where 50% coverage was achieved for both the 45 and 60 degree axial scans. No recordable indications detected.The completed examination was limited to 75%coverage due to the configuration. | PDI (Y/N) | ||
Exam limitations 2 2-RC-27 Upper Head to Relief B3.1 10 75.0/ (per Article were due to the contour of the weld on the nozzle Nozzle 4 of Section V) side, where 50% coverage was achieved for both the 45 and 60 degree axial scans. No recordable indications detected. | The completed examination was limited to 40.9% | ||
coverage due to the configuration. Due to the Inlet Nozzle Inside 40.9/N-(per component geometry, no coverage of the inner radius STM-14-1-IRS Radius Section B3.140 Article 4 of region can be effectively obtained by scanning from Section V) the shell side. No contact could be maintained in the blend radius area. No recordable indications detected. | |||
The completed examination was limited to 25% | |||
coverage due to the configuration. Due to the 25.0/N (per component geometry, no coverage of the inner radius IRSTRadOut IRS Radius Secions Section B3.140 Article 4 of region can be effectively obtained by scanning from Section V) the shell side. No contact could be maintained in the blend radius area. No recordable indications detected. | |||
The completed examination was limited to 34.9% | |||
coverage due to the configuration. Due to the 34.9/N (per component geometry, no coverage of the inner radius STM-12-1-IRS Radius Section B3.140 Article 4 of region can be effectively obtained by scanning from Section V) the shell side. No contact could be maintained in the blend radius area. No recordable indications detected. | |||
to AEP-NRC-2012-2 Page 17 Ultrasonic CNP ompoent tem Examination CNP Component Weld Description Itemb Coverage Remarks Unit ID Number Cvrg Attained (%)/ | |||
PDI (Y/N) | |||
The completed examination was limited to 36.8% | |||
coverage due to the configuration. Due to the 36.8/N (per component geometry, no coverage of the inner radius 1 STMRadiO-IRS ue N Section Radius ecions B3.140 Article 4 of region can be effectively obtained by scanning from Section V) the shell side. No contact could be maintained in the blend radius area. No recordable indications detected. | |||
The completed examination was limited to 75% | |||
coverage due to the configuration. Exam limitations 2 2-RC-26 Upper Head to Relief B3.110 75.0/ (per Article were due to the contour of the weld on the nozzle Nozzle 4 of Section V) side, where 50% coverage was achieved for both the 45 and 60 degree axial scans. No recordable indications detected. | |||
The completed examination was limited to 75% | |||
coverage due to the configuration. Exam limitations 2 2-RC-27 Upper Head to Relief B3.1 10 75.0/ (per Article were due to the contour of the weld on the nozzle Nozzle 4 of Section V) side, where 50% coverage was achieved for both the 45 and 60 degree axial scans. No recordable indications detected. | |||
to AEP-NRC-2012-2 Page 18 RELIEF REQUEST ISIR-35 EXAMINATION CATEGORY B-D FULL PENETRATION WELDS OF NOZZLES IN VESSELS - INSPECTION PROGRAM B SUPPORTING DOCUMENTATION IS PROVIDED BY I&M LETTER DATED APRIL 8, 2011 ADAMS ACCESSION NO. ML11110A042 to AEP-NRC-2012-2 Page 19 RELIEF REQUEST ISIR-36 EXAMINATION CATEGORY B-F PRESSURE RETAINING DISSIMILAR METAL WELDS to AEP-NRC-2012-2 Page 20 RELIEF REQUEST ISIR-36 Relief Request In Accordance with 10 CFR 50.55a(g)(5)(iii) | |||
Inservice Inspection Impracticality | Inservice Inspection Impracticality | ||
: 1. ASME Code Components Affected ASME Code Class: Code Class 1 Examination Category: | : 1. ASME Code Components Affected ASME Code Class: Code Class 1 Examination Category: B-F, Pressure Retaining Dissimilar Metal Welds Item Numbers: B5.70, Steam Generator, Nozzle to Safe End Butt Welds Component Identification: Listed in Table 1 | ||
B-F, Pressure Retaining Dissimilar Metal Welds Item Numbers: B5.70, Steam Generator, Nozzle to Safe End Butt Welds Component Identification: | |||
Listed in Table 1 2. Applicable Code Edition and Addenda ASME Section XI, 1989 Edition, No addenda 3. Applicable Code Requirement ASME Section Xl, 1989 Edition, Examination Category B-F requires volumetric examination of 100 percent of the weld volume as defined in Table IWB-2500-1 and shown in Figure IWB-2500-8. | ===2. Applicable Code Edition and Addenda=== | ||
The alternative requirements of ASME Section XI, Code Case N-460, approved for use in Regulatory Guide 1.147, Revision 15, allows credit for essentially 100 percent coverage of the welds provided greater than 90 percent of the required volume has been examined.4. Impracticality of Compliance Pursuant to 10 CFR 50.55a(g)(5)(iii), relief is requested from the essentially 100 percent volumetric examination coverage requirement for the subject welds due to the geometric configuration and permanent obstructions which limit the volumetric examination coverage of the subject welds.The Steam Generator Nozzle to Safe End examinations (STM-12-02R, STM-12-03R, STM-14-02R, and STM-14-03R) were limited to 25.72%, 23.92%, 25.72%, and 23.9%coverage respectively due to the component geometry. | ASME Section XI, 1989 Edition, No addenda | ||
Coverage was limited due to tapers, weld contours, and depressions on some of the nozzles.The Safe End to Elbow examinations (STM-22-02, STM-22-03, STM-23-02, and STM-23-03) were limited to 19.5%, 19.5%, 19.5% and 19.5% coverage respectively due to limitations encountered with the contour of the weld along with depressions on the nozzle side of the weld and the CASS Elbow material.These noted obstructions prevent achieving the essentially 100 percent volume examination coverage required by code. | |||
===3. Applicable Code Requirement=== | |||
Appendix VIII qualified (PDI) procedures have demonstrated that sound beams may potentially be attenuated and distorted when required to pass through austenitic weld metal. However, the PDI qualified methods employ the best available technology for maximizing examination coverage of these types of welds. For the components listed in this relief request, examination was extended to the far side of the weld to the extent permitted by geometry as qualified through PDI. Indiana Michigan Power Company (I&M) has used the best available techniques to examine the subject piping welds.To improve upon these examination coverage percentages, modification and/or replacement of the component would be required. | ASME Section Xl, 1989 Edition, Examination Category B-F requires volumetric examination of 100 percent of the weld volume as defined in Table IWB-2500-1 and shown in Figure IWB-2500-8. The alternative requirements of ASME Section XI, Code Case N-460, approved for use in Regulatory Guide 1.147, Revision 15, allows credit for essentially 100 percent coverage of the welds provided greater than 90 percent of the required volume has been examined. | ||
No alternative testing is proposed at this time. I&M has examined the subject welds to the extent practical and will continue to perform pressure testing on the subject welds as required by the Code. I&M also performed surface examinations of 100% of the required area without limitations. | : 4. Impracticality of Compliance Pursuant to 10 CFR 50.55a(g)(5)(iii), relief is requested from the essentially 100 percent volumetric examination coverage requirement for the subject welds due to the geometric configuration and permanent obstructions which limit the volumetric examination coverage of the subject welds. | ||
Additionally, for the welds consisting of CASS Elbow material (STM-22-02, STM-22-03, STM-23-02 and STM-23-03), there are currently no Appendix VIII PDI qualified procedures to inspect Cast Austenitic Stainless Steel (CASS) materials. | The Steam Generator Nozzle to Safe End examinations (STM-12-02R, STM-12-03R, STM-14-02R, and STM-14-03R) were limited to 25.72%, 23.92%, 25.72%, and 23.9% | ||
The Steam Generator Inlet and Outlet nozzle configuration includes an austenitic stainless steel safe-end welded to a cast austenitic stainless steel elbow. The Appendix VIII procedure qualified for the examination of austenitic stainless steel welds from the Outside Diameter surface was used to perform a best effort examination of the CASS elbow material.To increase examination coverage on the subject weld would require a significant design modification or replacement of components with a different design or material to eliminate the noted obstructions or material limitations. | coverage respectively due to the component geometry. Coverage was limited due to tapers, weld contours, and depressions on some of the nozzles. | ||
This is impractical due to the cost, additional radiation exposure, and impact to plant equipment. | The Safe End to Elbow examinations (STM-22-02, STM-22-03, STM-23-02, and STM-23-03) were limited to 19.5%, 19.5%, 19.5% and 19.5% coverage respectively due to limitations encountered with the contour of the weld along with depressions on the nozzle side of the weld and the CASS Elbow material. | ||
: 6. Proposed Alternative and Basis for Use The subject welds received a volumetric examination on the accessible portions of the subject welds to the maximum extent practical. | These noted obstructions prevent achieving the essentially 100 percent volume examination coverage required by code. | ||
Each weld also received a surface examination without limitations. | to AEP-NRC-2012-2 Page 21 The limitations and the actual examination coverage attained for each weld for which relief is requested are noted in Table 1. | ||
Additionally, a visual examination (VT-2) is performed at the end of each refueling outage during the system leakage tests as required by Section Xl, IWB-2500-1, Category B-P.Based upon the examination volumes that were obtained with acceptable results along with the completed surface examination and the visual (VT-2) examination performed each refueling outage, it is reasonable to conclude that service induced degradation would be | : 5. Burden Caused by Compliance Class 1 piping and components are often designed with welded joints such as nozzle-to-pipe, pipe-to valve, and pipe-to-pump which can physically obstruct a large portion of the required examination volume. For the welds listed in Table 1, the examinations were performed after the 10 CFR 50.55a mandatory implementation date (November 22, 2002) for Appendix VIII of Section Xl. The provided code coverage percentages reflect what is currently allowed by qualified Appendix VIII techniques. Appendix VIII qualified (PDI) procedures have demonstrated that sound beams may potentially be attenuated and distorted when required to pass through austenitic weld metal. However, the PDI qualified methods employ the best available technology for maximizing examination coverage of these types of welds. For the components listed in this relief request, examination was extended to the far side of the weld to the extent permitted by geometry as qualified through PDI. Indiana Michigan Power Company (I&M) has used the best available techniques to examine the subject piping welds. | ||
Therefore, these proposed alternatives provide an acceptable level of quality and safety by providing reasonable assurance of structural integrity of the subject welds.7. Period for Which Relief is Requested The relief is requested for the Third 10-year inspection interval for Donald C. Cook Nuclear Plant Units 1 and 2, which began on July 1, 1996, and ended April 9, 2010, at the conclusion of the Unit 1 Cycle 23 Refueling Outage. Significant long-term outages (greater than six months) occurred multiple times during the interval and the interval was extended as allowed by IWA-2430(e) and by IWA-2430(d) to accommodate interval planning and scheduling. | To improve upon these examination coverage percentages, modification and/or replacement of the component would be required. No alternative testing is proposed at this time. I&M has examined the subject welds to the extent practical and will continue to perform pressure testing on the subject welds as required by the Code. I&M also performed surface examinations of 100% of the required area without limitations. | ||
Additionally, for the welds consisting of CASS Elbow material (STM-22-02, STM-22-03, STM-23-02 and STM-23-03), there are currently no Appendix VIII PDI qualified procedures to inspect Cast Austenitic Stainless Steel (CASS) materials. The Steam Generator Inlet and Outlet nozzle configuration includes an austenitic stainless steel safe-end welded to a cast austenitic stainless steel elbow. The Appendix VIII procedure qualified for the examination of austenitic stainless steel welds from the Outside Diameter surface was used to perform a best effort examination of the CASS elbow material. | |||
The 1 02R Nozzle B5.70 25.72NY limited coverage of this weld is due to the configuration of the taper transition of the safe end. No recordable indications detected.The completed examination was limited to STMI Safe End to Inlet 23.92% coverage due to the configuration. | To increase examination coverage on the subject weld would require a significant design modification or replacement of components with a different design or material to eliminate the noted obstructions or material limitations. This is impractical due to the cost, additional radiation exposure, and impact to plant equipment. | ||
The 1 03R Nozzle B5.70 23.92/Y limited coverage of this weld is due to the configuration of the taper transition of the safe end. No recordable indications detected.The completed examination was limited to STM Safe End to Inlet 25.72% coverage due to the configuration. | : 6. Proposed Alternative and Basis for Use The subject welds received a volumetric examination on the accessible portions of the subject welds to the maximum extent practical. Each weld also received a surface examination without limitations. Additionally, a visual examination (VT-2) is performed at the end of each refueling outage during the system leakage tests as required by Section Xl, IWB-2500-1, Category B-P. | ||
The 1 02R Nozzle B5.70 25.72/Y limited coverage of this weld is due to the configuration of the taper transition of the safe end. No recordable indications detected.The completed examination was limited to 23.9%STM Safe End to Inlet coverage due to the configuration. | Based upon the examination volumes that were obtained with acceptable results along with the completed surface examination and the visual (VT-2) examination performed each refueling outage, it is reasonable to conclude that service induced degradation would be to AEP-NRC-2012-2 Page 22 detected. Therefore, these proposed alternatives provide an acceptable level of quality and safety by providing reasonable assurance of structural integrity of the subject welds. | ||
The limited 1 03R Nozzle B5.70 23.9/Y coverage of this weld is due to the configuration of the taper transition of the safe end. No recordable indications detected.The completed examination was limited to 19.5%coverage due to the configuration. | : 7. Period for Which Relief is Requested The relief is requested for the Third 10-year inspection interval for Donald C. Cook Nuclear Plant Units 1 and 2, which began on July 1, 1996, and ended April 9, 2010, at the conclusion of the Unit 1 Cycle 23 Refueling Outage. Significant long-term outages (greater than six months) occurred multiple times during the interval and the interval was extended as allowed by IWA-2430(e) and by IWA-2430(d) to accommodate interval planning and scheduling. | ||
Limitations Elbow to Inlet were encountered due the contour of the weld Nozzle along with depressions on the nozzle side of the weld and the CASS Elbow material. | to AEP-NRC-2012-2 Page 23 Table 1 to Relief Request ISIR-36 Ultrasonic CNP Component Weld Item Examination Coverage Remarks Unit ID Description Number Attained (%)/ | ||
No relevant indications detected. | PDI (Y/N) | ||
The completed examination was limited to STMI Safe End to Inlet 25.72% coverage due to the configuration. The 1 02R Nozzle B5.70 25.72NY limited coverage of this weld is due to the configuration of the taper transition of the safe end. No recordable indications detected. | |||
Limitations were encountered due the contour | The completed examination was limited to STMI Safe End to Inlet 23.92% coverage due to the configuration. The 1 03R Nozzle B5.70 23.92/Y limited coverage of this weld is due to the configuration of the taper transition of the safe end. No recordable indications detected. | ||
No relevant indications detected.The completed examination was limited to 19.5%coverage due to the configuration. | The completed examination was limited to STM Safe End to Inlet 25.72% coverage due to the configuration. The 1 02R Nozzle B5.70 25.72/Y limited coverage of this weld is due to the configuration of the taper transition of the safe end. No recordable indications detected. | ||
Limitations were encountered due the contour | The completed examination was limited to 23.9% | ||
No relevant indications detected.The completed examination was limited to 19.5%coverage due to the configuration. | STM Safe End to Inlet coverage due to the configuration. The limited 1 03R Nozzle B5.70 23.9/Y coverage of this weld is due to the configuration of the taper transition of the safe end. No recordable indications detected. | ||
Limitations were encountered due the contour | The completed examination was limited to 19.5% | ||
No relevant indications detected. | coverage due to the configuration. Limitations Elbow to Inlet were encountered due the contour of the weld Nozzle along with depressions on the nozzle side of the weld and the CASS Elbow material. No relevant indications detected. | ||
to AEP-NRC-2012-2 Page 24 Ultrasonic CNP Component WItem Examination Unit ID Weld Description Number Coverage Attained (M)Y PDI (Y/N) | |||
The completed examination was limited to 19.5% | |||
coverage due to the configuration. Limitations 19.5/Y were wr encountered nonee due u the h contour otu offtewl the weld 2 STM-22-03 Elbow to Inlet Nozzle B5.70 along with depressions on the nozzle side of the weld and the CASS Elbow material. No relevant indications detected. | |||
The completed examination was limited to 19.5% | |||
coverage due to the configuration. Limitations 19.5/Y were wr encountered nonee due u the h contour otu offtewl the weld 2 STM-23-02 Elbow to Inlet Nozzle B5.70 along with depressions on the nozzle side of the weld and the CASS Elbow material. No relevant indications detected. | |||
The completed examination was limited to 19.5% | |||
coverage due to the configuration. Limitations B5.70 were encountered due the contour offtewl 19.5N/eeecutrddethYotu the weld 2 STM-23-03 Outlet Nozzle to Elbow along with depressions on the nozzle side of the weld and the CASS Elbow material. No relevant indications detected. | |||
to AEP-NRC-2012-2 Page 25 RELIEF REQUEST ISIR-36 EXAMINATION CATEGORY B-F PRESSURE RETAINING DISSIMILAR METAL WELDS SUPPORTING DOCUMENTATION IS PROVIDED BY I&M LETTER DATED APRIL 8, 2011 ADAMS ACCESSION NO. ML1111OA042 to AEP-NRC-2012-2 Page 26 RELIEF REQUEST ISIR-37 EXAMINATION CATEGORY B-J PRESSURE RETAINING WELDS IN PIPING to AEP-NRC-2012-2 Page 27 RELIEF REQUEST ISIR-37 Relief Request In Accordance with 10 CFR 50.55a(g)(5)(iii) | |||
Inservice Inspection Impracticality | |||
: 1. ASME Code Components Affected ASME Code Class: Code Class 1 Examination Category: B-J, Pressure Retaining Welds in Piping Item Numbers: B9.1 1, NPS 4 and Larger, Circumferential Welds B9.31, Branch Pipe Connection Welds, NPS 4 or Larger Component Identification: Listed in Table 1 | |||
===2. Applicable Code Edition and Addenda=== | |||
ASME Section XI, 1989 Edition, No addenda | |||
===3. Applicable Code Requirement=== | |||
ASME Section Xl, 1989 Edition, Examination Category B-J requires volumetric examination of 100 percent of the weld volume as defined in Table IWB-2500-1 and shown in Figures IWB-2500-8, or IWB-2500-9, -10 or -11. The alternative requirements of ASME Section Xl, Code Case N-460, approved for use in Regulatory Guide 1.147, Revision 15, allows credit for essentially 100 percent coverage of the welds provided greater than 90 percent of the required volume has been examined. | |||
: 4. Impracticality of Compliance Pursuant to 10 CFR 50.55a(g)(5)(iii), relief is requested from the essentially 100 percent volumetric examination coverage requirement for the subject welds due to the geometric configuration and permanent obstructions which limit the volumetric examination coverage of the subject welds. | |||
Due to the component geometry coverage was limited due to tapers, bevels, weld contours, and joint configurations. | |||
These noted obstructions prevent achieving the essentially 100 percent volume examination coverage required by code. | |||
The limitations and the actual examination coverage attained for each weld for which relief is requested are noted in Table 1. | |||
to AEP-NRC-2012-2 Page 28 | |||
: 5. Burden Caused by Compliance During ultrasonic examination of the piping welds listed in Table 1 of this relief request, 100 percent coverage of the required examination volume could not be obtained. Class 1 piping and components are often designed with welded joints such as nozzle-to-pipe, pipe-to-valve, and pipe-to-pump which can physically obstruct a large portion of the required examination volume. For the welds listed in Table 1, the examinations were performed using Appendix VIII of Section Xl as modified by the PDI program. The provided code coverage percentages reflect what is allowed by qualified Appendix VIII techniques. Appendix VIII qualified PDI procedures have demonstrated that sound beams may potentially be attenuated and distorted when required to pass through austenitic weld metal. However, the PDI qualified methods employ the best available technology for maximizing examination coverage of these types of welds. For all the components listed in this relief request, examination was extended to the far side of the weld to the extent permitted by geometry, but this portion of the examination is not included in the reported coverage for welds examined under PDI and Appendix VIII rules. Indiana Michigan Power Company (I&M) has used the best available techniques to examine the subject piping welds. To improve upon these examination coverage percentages, modification and/or replacement of the component would be required. | |||
No alternative testing is proposed at this time. I&M has examined the subject welds to the extent practical and will continue to perform pressure testing on the subject welds as required by the Code. | |||
To increase examination coverage on the subject weld would require a significant design modification or replacement of components with a different design or material to eliminate the noted obstructions or material limitations. This is impractical due to the cost, additional radiation exposure and impact to plant equipment. | |||
: 6. Proposed Alternative and Basis for Use The subject welds received a volumetric examination on the accessible portions of the subject welds to the maximum extent practical. Each weld also received a surface examination without limitations. Additionally, a visual examination (VT-2) is performed at the end of each refueling outage during the system leakage tests as required by Section Xl, IWB-2500-1, Category B-P. | |||
Based upon the examination volumes that were obtained with acceptable results along with the completed surface examination and the visual (VT-2) examination performed each refueling outage, it is reasonable to conclude that service induced degradation would be detected if present. Therefore, these proposed alternatives provide an acceptable level of quality and safety by providing reasonable assurance of structural integrity of the subject welds. | |||
to AEP-NRC-2012-2 Page 29 | |||
: 7. Period for Which Relief is Requested The relief is requested for the Third 10-year inspection interval for Donald C. Cook Nuclear Plant Units 1 and 2, which began on July 1, 1996, and ended April 9, 2010, at the conclusion of the Unit 1 Cycle 23 Refueling Outage. Significant long-term outages (greater than six months) occurred multiple times during the interval and the interval was extended as allowed by IWA-2430(e) and by IWA-2430(d) to accommodate interval planning and scheduling. | |||
to AEP-NRC-2012-2 Page 30 Table 1 to Relief Request ISIR-37 Ultrasonic CNP Component Weld Item Examination Coverage Remarks Unit ID Description Number Attained (%)/ | |||
PDI (Y/N) | |||
The completed examination was limited to 50% | |||
1-RH coverage due to the configuration. The configuration 1 05F Pipe to Pipe B9.11 50.0/Y prevents examination on the penetration side due to the bevel and the contour of the ID and OD. No relevant indications detected. | |||
The completed examination was limited to 50% | |||
coverage due to the configuration. The coverage 1 1-SI-22-18F Pipe to B9.11 50.0/Y limitation was due to the OD bevel configuration on the Valve valve side of the weld. No relevant indications detected. | |||
The completed examination was limited to 50% | |||
coverage due to the configuration. The coverage 1 1-SI-23-17F Pipe to B9.11 50.0/Y limitation was due to the OD bevel configuration on the Valve valve side of the weld. No relevant indications detected. | |||
The completed examination was limited to 50% | |||
Branch to coverage due to the configuration. The exam limitation 1 1-RC-5-01F Pipe B9.11 50.0/Y was due to the proximity of the branch connection to the branch side weld. No relevant indications detected. | |||
The completed examination was limited to 50% | |||
coverage due to the configuration. The configuration 1 1-SI-33-23S Tee to Pipe B9.11 50.0/Y prevents examination on the tee side due to the sharp bevel adjacent to the tee side weld toe. No relevant indications detected. | |||
to AEP-NRC-2012-2 Page 31 Ultrasonic CNP Component Weld Item Examination Coverage Remarks Unit ID Description Number Attained (%)/ | |||
PDI (Y/N) | |||
The completed examination was limited to 65% | |||
2 2-RC-22-01 Safe End to B9.11 65.0Y coverage due to the configuration. The configuration Elbow prevents examination due to the geometry of the safe end. No relevant indications detected. | |||
The completed examination was limited to 66.7% | |||
coverage due to the configuration. The configuration 2 2-RC-28-23 Tee to Pipe B9.11 66.7/Y prevents examination on the tee side due to the sharp bevel adjacent to the tee side weld toe. No relevant indications detected. | |||
The completed examination was limited to 50% | |||
coverage due to the configuration. The configuration 2 2-SI-56-19 Tee to Pipe B9.11 50.O0Y prevents examination on the tee side due to the sharp bevel adjacent to the tee side weld toe. No relevant indications detected. | |||
The completed examination was limited to 50% | |||
Branch to coverage due to the configuration. The configuration 2 2-RH-33-01 Pipe B9.11 50.O/Y prevents examination on the tee side due to the sharp bevel adjacent to the tee side weld toe. No relevant indications detected. | |||
The completed examination was limited to 34% | |||
coverage due to the configuration. Limitations were based on the joint configuration. No axial scans were 2-RC Branch to performed on the downstream side of the weld along 2 08N Brnc B9.31 34.O0Y with no circumferential scans on the branch connection 08N Pipe weld due to the contour of the weld. In addition, circumferential scans could only be performed on the branch connection base material. No relevant indications detected. | |||
to AEP-NRC-2012-2 Page 32 RELIEF REQUEST ISIR-37 EXAMINATION CATEGORY B-J PRESSURE RETAINING WELDS IN PIPING SUPPORTING DOCUMENTATION IS PROVIDED BY I&M LETTER DATED APRIL 8, 2011 ADAMS ACCESSION NO. ML11110A042 to AEP-NRC-2012-2 Page 33 RELIEF REQUEST ISIR-38 EXAMINATION CATEGORY C-A PRESSURE RETAINING WELDS IN PRESSURE VESSELS to AEP-NRC-2012-2 Page 34 RELIEF REQUEST ISIR-38 Relief Requested In Accordance with 10 CFR 50.55a(g)(5)(iii) - | |||
Inservice Inspection Impracticality | Inservice Inspection Impracticality | ||
: 1. ASME Code Components Affected ASME Code Class: Code Class | : 1. ASME Code Components Affected ASME Code Class: Code Class 2 Examination Category: C-A, Pressure Retaining Welds in Pressure Vessels Item Numbers: C1.10, Shell Circumferential Welds C1.20, Head Circumferential Welds C1.30, Tubesheet to Shell Weld Component Identification: Listed in Table 1 | ||
Listed in Table 1 2. Applicable Code Edition and Addenda ASME Section | ===2. Applicable Code Edition and Addenda=== | ||
These noted obstructions prevent achieving the essentially 100 percent volume examination coverage required by code.The limitations and the actual examination coverage attained for each weld for which relief is requested are noted in Table 1. | ASME Section Xl, 1989 Edition, No addenda | ||
===3. Applicable Code Requirement=== | |||
ASME Section Xl, 1989 Edition, Examination Category C-A requires volumetric examination of 100 percent of the weld volume as defined in Table IWC-2500-1 and shown in Figures IWC-2500-1 or IWC-2500-2 as applicable. The alternative requirements of ASME Section Xl, Code Case N-460, approved for use in Regulatory Guide 1.147, Revision 15, allows credit for essentially 100 percent coverage of the welds provided greater than 90 percent of the required volume has been examined. | |||
: 4. Impracticality of Compliance Pursuant to 10 CFR 50.55a(g)(5)(iii), relief is requested from the essentially 100 percent volumetric examination coverage requirement for the subject weld due to the geometric configuration and permanent obstructions which limit the volumetric examination coverage of the subject welds. | |||
These noted obstructions prevent achieving the essentially 100 percent volume examination coverage required by code. | |||
The limitations and the actual examination coverage attained for each weld for which relief is requested are noted in Table 1. | |||
to AEP-NRC-2012-2 Page 35 5, Burden Caused by Compliance To increase examination coverage on the subject welds requires removal of the permanently welded pads, supports, electrical supports, adjacent piping and nozzles or replacement of the heat exchanger with a design that would allow for complete examination coverage of the subject weld. This option to meet the 100 percent code examination requirement is considered impractical due to the cost, increased radiation exposure and impact to plant equipment. | |||
6, Proposed Alternative and Basis for Use The subject welds received a volumetric examination utilizing the best available techniques on the accessible portions of welds to the extent practical. Additionally, a visual (VT-2) examination is performed during each inspection period during the system leakage tests as required by Section Xl, Table IWC-2500-1, Category C-H. | |||
Based upon the examination volumes that were attained with acceptable results along with the visual (VT-2) examination performed each inspection period, it is reasonable to conclude that service induced degradation would be detected. Therefore, these proposed alternatives provide an acceptable level of quality and safety by providing reasonable assurance of structural integrity of the subject welds. | |||
The | : 7. Period for Which Relief is Requested The relief is requested for the Third 10-year inspection interval for Donald C. Cook Nuclear Plant Units 1 and 2, which began on July 1, 1996, and ended April 9, 2010, at the conclusion of the Unit 1 Cycle 23 Refueling Outage. Significant long-term outages (greater than six months) occurred multiple times during the interval and the interval was extended as allowed by IWA-2430(e) and by IWA-2430(d) to accommodate interval planning and scheduling. | ||
to AEP-NRC-2012-2 Page 36 Table 1 to Relief Request ISIR-38 Ultrasonic CNP Component Weld Item Examination Coverage Remarks Unit ID Description Number Attained (%)/ | |||
PDI (Y/N) | |||
The completed examination was limited to 48.1% | |||
coverage due to the configuration. The examination Shell to was single sided due to the proximity of the flange and 2 W-CTSHEX-2 Flange C1.10 48.1/Y its associated bolting. Exam limitation on the accessible side was due to the inlet and outlet nozzles restricting access for an 11" area of the weld. No relevant indications detected. | |||
The completed examination was limited to 80.5% | |||
Shell to Lower C80.5/N (per Article 4 of coverage due to the configuration. The examination 2 2-BIT-A SHell t01.20 8 (e rtic 4 limitation was due to four leg supports located along Head Section V) the weld from 0 degrees at 18"-26", 62"-70", 99"-107", | |||
and 142"-150". No relevant indications detected. | |||
The completed examination was limited to 85% | |||
coverage due to the configuration. Examination Tube Sheet to 85.0/ N (per Article 4 of coverage was limited due to the proximity of welded Stub Barrel Section V) pads, nozzles, adjacent piping, hand hole openings, permanent support brackets and permanent electrical conduits. No relevant indications detected. | |||
to AEP-NRC-2012-2 Page 37 RELIEF REQUEST ISIR-38 EXAMINATION CATEGORY C-A PRESSURE RETAINING WELDS IN PRESSURE VESSELS SUPPORTING DOCUMENTATION IS PROVIDED BY I&M LETTER DATED APRIL 8, 2011 ADAMS ACCESSION NO. ML11110A042 AND THE FOLLOWING TWO PAGES to AEP-NRC-2012-2 Page 38 LIMITATION SKETCH For FLANGE to SHELL WELD W-CTSHEX-2 to AEP-NRC-2012-2 Page 39 | |||
-/7INLE.T CONN.I t.F..ThL sr'o£5a..ccs'oL* _t,. | |||
MATMLN .1*i,8 I | |||
,'ITiL.- | |||
.-_.G TO BF F- ^I,-F_.L. | |||
rn7vp Limitations for Shell to Lower Head Weld 2-BIT-A to AEP-NRC-2012-2 Page 40 RELIEF REQUEST ISIR-39 EXAMINATION CATEGORY C-B PRESSURE RETAINING NOZZLE WELDS IN VESSELS to AEP-NRC-2012-2 Page 41 RELIEF REQUEST ISIR-39 Relief Request In Accordance with 10 CFR 50.55a(g)(5)(iii) | |||
Inservice Inspection Impracticality | Inservice Inspection Impracticality | ||
: 1. ASME Code Components Affected ASME Code Class: Code Class 2 Examination Category: | : 1. ASME Code Components Affected ASME Code Class: Code Class 2 Examination Category: C-B, Pressure Retaining Nozzle Welds in Vessels Item Numbers: C2.21, Nozzles Without Reinforcing Plate in Vessels > 1/ inch Nominal Thickness, Nozzle to Shell (or Head) Weld Component Identification: Listed in Table 1 | ||
C-B, Pressure Retaining Nozzle Welds in Vessels Item Numbers: C2.21, Nozzles Without Reinforcing Plate in Vessels > 1/ inch Nominal Thickness, Nozzle to Shell (or Head) Weld Component Identification: | |||
Listed in Table 1 2. Applicable Code Edition and Addenda ASME Section Xl, 1989 Edition, No addenda 3. Applicable Code Requirement ASME Section Xl, 1989 Edition, Examination Category C-B requires volumetric examination of 100 percent of the weld volume as defined in Table IWC-2500-1 and shown in Figures IWC-2500-4(a) or IWC-2500-4(b) as applicable. | ===2. Applicable Code Edition and Addenda=== | ||
The alternative requirements of ASME Section Xl, Code Case N-460, approved for use in Regulatory Guide 1.147, Revision 15, allows credit for essentially 100 percent coverage of the welds provided greater than 90 percent of the required volume has been examined.4. Impracticality of Compliance Pursuant to 10 CFR 50.55a(g)(5)(iii), relief is requested from the essentially 100 percent volumetric examination coverage requirement for the subject welds due to the geometric configuration and permanent obstructions which limits the volumetric examination coverage of the subject welds.Due to the component geometry, coverage was limited due to tapers, bevels, weld contours, and joint configurations. | ASME Section Xl, 1989 Edition, No addenda | ||
These noted obstructions prevent achieving the essentially 100 percent volume examination coverage required by code.The limitations and the actual examination coverage attained for each weld for which relief is requested are noted in Table 1. | |||
===3. Applicable Code Requirement=== | |||
: 6. Proposed Alternative and Basis for Use The subject welds received a volumetric examination utilizing the best available techniques on the accessible portions of welds to the extent practical. | ASME Section Xl, 1989 Edition, Examination Category C-B requires volumetric examination of 100 percent of the weld volume as defined in Table IWC-2500-1 and shown in Figures IWC-2500-4(a) or IWC-2500-4(b) as applicable. The alternative requirements of ASME Section Xl, Code Case N-460, approved for use in Regulatory Guide 1.147, Revision 15, allows credit for essentially 100 percent coverage of the welds provided greater than 90 percent of the required volume has been examined. | ||
Additionally, a surface examination without any limitations was performed along with a visual (VT-2) examination that is performed during each inspection period during the system leakage tests as required by Section Xl, Table IWC-2500-1, Category C-H.Based upon the examination volumes that were attained along with acceptable results and the acceptable surface examination that was performed and the visual (VT-2) examination performed each inspection period, it is reasonable to conclude that service induced degradation would be detected. | : 4. Impracticality of Compliance Pursuant to 10 CFR 50.55a(g)(5)(iii), relief is requested from the essentially 100 percent volumetric examination coverage requirement for the subject welds due to the geometric configuration and permanent obstructions which limits the volumetric examination coverage of the subject welds. | ||
Therefore, these proposed alternatives provide an acceptable level of quality and safety by providing reasonable assurance of structural integrity of the subject welds.7. Period for Which Relief is Requested The relief is requested for the Third 10-year inspection interval for Donald C. Cook Nuclear Plant Units 1 and 2, which began on July 1, 1996, and ended April 9, 2010, at the conclusion of the Unit 1 Cycle 23 Refueling Outage. Significant long-term outages (greater than six months) occurred multiple times during the interval and the interval was extended as allowed by IWA-2430(e) and by IWA-2430(d) to accommodate interval planning and scheduling. | Due to the component geometry, coverage was limited due to tapers, bevels, weld contours, and joint configurations. | ||
These noted obstructions prevent achieving the essentially 100 percent volume examination coverage required by code. | |||
The coverage STM Nozzle to Shell C2.21 46.5/N (per Article 4 of limitation was due to the proximity of insulation and a FWN Section V) metal strap at top-dead-center and at bottom-dead-center due to the shell weld. No relevant indications detected. | The limitations and the actual examination coverage attained for each weld for which relief is requested are noted in Table 1. | ||
to AEP-NRC-2012-2 Page 42 | |||
: 5. Burden Caused by Compliance To increase examination coverage on the subject welds requires removal of significant portions of insulation and its supporting elements and redesign of the blend radius of the nozzle to shell weld with a design that would allow for complete examination coverage of the subject weld. This option to meet the 100 percent code examination requirement is considered impractical due to the cost, increased radiation exposure and impact to plant equipment. | |||
: 6. Proposed Alternative and Basis for Use The subject welds received a volumetric examination utilizing the best available techniques on the accessible portions of welds to the extent practical. Additionally, a surface examination without any limitations was performed along with a visual (VT-2) examination that is performed during each inspection period during the system leakage tests as required by Section Xl, Table IWC-2500-1, Category C-H. | |||
Based upon the examination volumes that were attained along with acceptable results and the acceptable surface examination that was performed and the visual (VT-2) examination performed each inspection period, it is reasonable to conclude that service induced degradation would be detected. Therefore, these proposed alternatives provide an acceptable level of quality and safety by providing reasonable assurance of structural integrity of the subject welds. | |||
: 7. Period for Which Relief is Requested The relief is requested for the Third 10-year inspection interval for Donald C. Cook Nuclear Plant Units 1 and 2, which began on July 1, 1996, and ended April 9, 2010, at the conclusion of the Unit 1 Cycle 23 Refueling Outage. Significant long-term outages (greater than six months) occurred multiple times during the interval and the interval was extended as allowed by IWA-2430(e) and by IWA-2430(d) to accommodate interval planning and scheduling. | |||
to AEP-NRC-2012-2 Page 43 Table 1 to Relief Request ISIR-39 Ultrasonic CNP Component Weld Item Examination Unit ID Description Number Coverage Attained Remarks PDI (Y/N) | |||
The completed examination was limited to 46.5% | |||
coverage due to the configuration. The coverage STM Nozzle to Shell C2.21 46.5/N (per Article 4 of limitation was due to the proximity of insulation and a FWN Section V) metal strap at top-dead-center and at bottom-dead-center due to the shell weld. No relevant indications detected. | |||
to AEP-NRC-2012-2 Page 44 RELIEF REQUEST ISIR-39 EXAMINATION CATEGORY C-B PRESSURE RETAINING NOZZLE WELDS IN VESSELS SUPPORTING DOCUMENTATION IS PROVIDED BY I&M LETTER DATED APRIL 8, 2011 ADAMS ACCESSION NO. ML11110A042 to AEP-NRC-2012-2 Page 45 RELIEF REQUEST ISIR-40 EXAMINATION CATEGORY C-C INTEGRAL ATTACHMENTS FOR VESSELS, PIPING, PUMPS AND VALVES to AEP-NRC-2012-2 Page 46 RELIEF REQUEST ISIR-40 Relief Request In Accordance with 10 CFR 50.55a(g)(5)(iii) | |||
Inservice Inspection Impracticality | Inservice Inspection Impracticality | ||
: 1. ASME Code Components Affected ASME Code Class: Code Class 2 Examination Category: | : 1. ASME Code Components Affected ASME Code Class: Code Class 2 Examination Category: C-C, Integral Attachments for Vessels, Piping, Pumps and Valves Item Numbers: C3.20, Pumps, Integrally Welded Attachments C3.40, Valves, Integrally Welded Attachments Component Identification: Listed in Table 1 | ||
C-C, Integral Attachments for Vessels, Piping, Pumps and Valves Item Numbers: C3.20, Pumps, Integrally Welded Attachments C3.40, Valves, Integrally Welded Attachments Component Identification: | |||
Listed in Table 1 2. Applicable Code Edition and Addenda ASME Section Xl, 1989 Edition, No addenda 3. Applicable Code Requirement ASME Section Xl, 1989 Edition, Examination Category C-C requires surface examination of 100 percent of the weld as defined in Table IWC-2500-1 and shown in Figure IWC-2500-5. | ===2. Applicable Code Edition and Addenda=== | ||
The alternative requirements of ASME Section Xl, Code Case N-460, approved for use in Regulatory Guide 1.147, Revision 15, allows credit for essentially 100 percent coverage of the weld provided greater than 90 percent of the required area has been examined.4. Impracticality of Compliance Pursuant to 10 CFR 50.55a(g)(5)(iii), relief is requested from the essentially 100 percent surface examination coverage requirement for the subject Weld due to the permanently attached support orientation and permanently embedded bolting obstructions which limits the surface examination coverage of the subject weld.These noted obstructions prevent achieving the essentially 100 percent volume examination coverage required by code.The limitations and the actual examination coverage attained for each weld for which relief is requested are noted in Table 1.5. Burden Caused by Compliance To increase the examination coverage on the subject. weld requires removal of the permanent structural steel support member by physically cutting the support members apart and replacing the support members by re-welding following the completion of the surface examination. | ASME Section Xl, 1989 Edition, No addenda | ||
Removal of the permanently welded support members is considered to be | |||
: 6. Proposed Alternative and Basis for Use The subject welds received a surface examination utilizing the best available techniques on the accessible portions of welds to the extent practical. | ===3. Applicable Code Requirement=== | ||
Additionally, a visual (VT-2)examination is performed during each inspection period during the system leakage tests as required by Section Xl, Table IWC-2500-1, Category C-H.Based upon the examination volumes that were attained along with acceptable results and the acceptable visual (VT-2) examination performed each inspection period, it is reasonable to conclude that service induced degradation would be detected. | ASME Section Xl, 1989 Edition, Examination Category C-C requires surface examination of 100 percent of the weld as defined in Table IWC-2500-1 and shown in Figure IWC-2500-5. | ||
Therefore, these proposed alternatives provide an acceptable level of quality and safety by providing reasonable assurance of structural integrity of the subject welds.7. Period for Which Relief is Requested The relief is requested for the Third 10-year inspection interval for Donald C. Cook Nuclear Plant Units 1 and 2, which began on July 1, 1996, and ended April 9, 2010, at the conclusion of the Unit 1 Cycle 23 Refueling Outage. Significant long-term outages (greater than six months) occurred multiple times during the interval and the interval was extended as allowed by IWA-2430(e) and by IWA-2430(d) to accommodate interval planning and scheduling. | The alternative requirements of ASME Section Xl, Code Case N-460, approved for use in Regulatory Guide 1.147, Revision 15, allows credit for essentially 100 percent coverage of the weld provided greater than 90 percent of the required area has been examined. | ||
: 4. Impracticality of Compliance Pursuant to 10 CFR 50.55a(g)(5)(iii), relief is requested from the essentially 100 percent surface examination coverage requirement for the subject Weld due to the permanently attached support orientation and permanently embedded bolting obstructions which limits the surface examination coverage of the subject weld. | |||
Base metal examinations were limited 11 S-PS Pipe due to inner and outer cooler interference. | These noted obstructions prevent achieving the essentially 100 percent volume examination coverage required by code. | ||
No Attachment relevant indications detected.The completed examination was limited to 83.3%coverage due to the configuration. | The limitations and the actual examination coverage attained for each weld for which relief is requested are noted in Table 1. | ||
The limitation on MSIV-MRV-Integrally the extent of the coverage for the bottom horizontal 230-S2 Welded 03.40 83.3/Not Applicable attachment weld was based on the orientation of the Support attached support in relation to the weld. No relevant indications detected. | : 5. Burden Caused by Compliance To increase the examination coverage on the subject. weld requires removal of the permanent structural steel support member by physically cutting the support members apart and replacing the support members by re-welding following the completion of the surface examination. Removal of the permanently welded support members is considered to be to AEP-NRC-2012-2 Page 47 impractical based due to increased cost, potential for increased radiation exposure, and impact to plant equipment. | ||
: 6. Proposed Alternative and Basis for Use The subject welds received a surface examination utilizing the best available techniques on the accessible portions of welds to the extent practical. Additionally, a visual (VT-2) examination is performed during each inspection period during the system leakage tests as required by Section Xl, Table IWC-2500-1, Category C-H. | |||
Based upon the examination volumes that were attained along with acceptable results and the acceptable visual (VT-2) examination performed each inspection period, it is reasonable to conclude that service induced degradation would be detected. Therefore, these proposed alternatives provide an acceptable level of quality and safety by providing reasonable assurance of structural integrity of the subject welds. | |||
: 7. Period for Which Relief is Requested The relief is requested for the Third 10-year inspection interval for Donald C. Cook Nuclear Plant Units 1 and 2, which began on July 1, 1996, and ended April 9, 2010, at the conclusion of the Unit 1 Cycle 23 Refueling Outage. Significant long-term outages (greater than six months) occurred multiple times during the interval and the interval was extended as allowed by IWA-2430(e) and by IWA-2430(d) to accommodate interval planning and scheduling. | |||
to AEP-NRC-2012-2 Page 48 Table 1 to Relief Request ISIR-40 Ultrasonic Examination CNP Component Weld Item Covrage AtainetiRa Remarks Unit ID Description Number CoveragePDIAttained (Y/N) | |||
Integrally The completed examination was limited to 64% due to 1-MS Welded C3.20 64/Not Applicable configuration. Base metal examinations were limited 11 S-PS Pipe due to inner and outer cooler interference. No Attachment relevant indications detected. | |||
The completed examination was limited to 83.3% | |||
coverage due to the configuration. The limitation on MSIV-MRV- Integrally the extent of the coverage for the bottom horizontal 230-S2 Welded 03.40 83.3/Not Applicable attachment weld was based on the orientation of the Support attached support in relation to the weld. No relevant indications detected. | |||
to AEP-NRC-2012-2 Page 49 RELIEF REQUEST ISIR-40 EXAMINATION CATEGORY C-C INTEGRAL ATTACHMENTS FOR VESSELS, PIPING, PUMPS AND VALVES SUPPORTING DOCUMENTATION IS PROVIDED BY I&M LETTER DATED APRIL 8, 2011 ADAMS ACCESSION NO. ML11111OA042 to AEP-NRC-2012-2 Page 50 RELIEF REQUEST ISIR-41 EXAMINATION CATEGORY C-F-1 PRESSURE RETAINING WELDS IN AUSTENITIC STAINLESS STEEL OR HIGH ALLOY PIPING to AEP-NRC-2012-2 Page 51 RELIEF REQUEST ISIR-41 Relief Request In Accordance with 10 CFR 50.55a(g)(5)(iii) | |||
Inservice Inspection Impracticality | Inservice Inspection Impracticality | ||
: 1. ASME Code Components Affected ASME Code Class: Code Class 2 Examination Category: | : 1. ASME Code Components Affected ASME Code Class: Code Class 2 Examination Category: C-F-i, Item Numbers: C5.1 1, Piping Welds > 3/8 inch Nominal Wall Thickness for Piping | ||
C-F-i, Item Numbers: C5.1 1, Piping Welds > 3/8 inch Nominal Wall Thickness for Piping> NPS 4, Circumferential Weld C5.21, Piping Welds > 1/5 inch Nominal Wall Thickness for Piping> NPS 2 and < NPS 4, Circumferential Weld Component Identification: | > NPS 4, Circumferential Weld C5.21, Piping Welds > 1/5 inch Nominal Wall Thickness for Piping | ||
Listed in Table 1 2. Applicable Code Edition and Addenda ASME Section Xl, 1989 Edition, No addenda Austenitic piping welds with single side access subject to ultrasonic examination with Supplement 2 of Appendix VIll to the 1995 Edition with 1996 Addenda of ASME Section XI.3. Applicable Code Requirement ASME Section Xl, 1989 Edition, Examination Category C-F-1 requires volumetric examination of 100 percent of the weld volume as defined in Table IWC-2500-1 and shown in Figure IWC-2500-7. | > NPS 2 and < NPS 4, Circumferential Weld Component Identification: Listed in Table 1 | ||
The alternative requirements of ASME Section Xl, Code Case N-460, approved for use in Regulatory Guide 1.147, Revision 15, allows credit for essentially 100 percent coverage of the welds provided greater than 90 percent of the required volume has been examined.10 CFR 50.55a(b)(2)(xv)(A), requires the following examination coverage criteria when applying Supplement 2 to Appendix VIII: (1) Piping must be examined in two axial directions and when examination in the circumferential direction is required, the circumferential examination must be performed in two directions, provided access is available. | |||
===2. Applicable Code Edition and Addenda=== | |||
ASME Section Xl, 1989 Edition, No addenda Austenitic piping welds with single side access subject to ultrasonic examination with Supplement 2 of Appendix VIll to the 1995 Edition with 1996 Addenda of ASME Section XI. | |||
===3. Applicable Code Requirement=== | |||
ASME Section Xl, 1989 Edition, Examination Category C-F-1 requires volumetric examination of 100 percent of the weld volume as defined in Table IWC-2500-1 and shown in Figure IWC-2500-7. The alternative requirements of ASME Section Xl, Code Case N-460, approved for use in Regulatory Guide 1.147, Revision 15, allows credit for essentially 100 percent coverage of the welds provided greater than 90 percent of the required volume has been examined. | |||
10 CFR 50.55a(b)(2)(xv)(A), requires the following examination coverage criteria when applying Supplement 2 to Appendix VIII: | |||
(1) Piping must be examined in two axial directions and when examination in the circumferential direction is required, the circumferential examination must be performed in two directions, provided access is available. | |||
(2) Where examination from both sides is not possible, full coverage credit may be claimed from a single side for ferritic welds. Where examination from both sides is not possible on austenitic welds, full coverage credit from a single side may be claimed only after completing a successful single sided Appendix VIII demonstration using flaws on the opposite side of the weld. | (2) Where examination from both sides is not possible, full coverage credit may be claimed from a single side for ferritic welds. Where examination from both sides is not possible on austenitic welds, full coverage credit from a single side may be claimed only after completing a successful single sided Appendix VIII demonstration using flaws on the opposite side of the weld. | ||
to AEP-NRC-2012-2 Page 52 10 CFR 50.55a(b)(2)(xvi)(B), requires that examinations performed from one side of a ferritic or stainless steel pipe weld must be conducted with equipment, procedures, and personnel that have demonstrated proficiency with single side examinations. To demonstrate equivalency to the two sided examinations, the demonstration must be performed to the requirements of Appendix VIII as modified by this paragraph and 10 CFR 50.55a(b)(2)(xv)(A). | |||
To demonstrate equivalency to the two sided examinations, the demonstration must be performed to the requirements of Appendix VIII as modified by this paragraph and 10 CFR 50.55a(b)(2)(xv)(A). | : 4. Impracticality of Compliance Pursuant to 10 CFR 50.55a(g)(5)(iii), relief is requested from the essentially 100 percent volumetric examination coverage requirement for austenitic piping welds with single side access. | ||
: 4. Impracticality of Compliance Pursuant to 10 CFR 50.55a(g)(5)(iii), relief is requested from the essentially 100 percent volumetric examination coverage requirement for austenitic piping welds with single side access.There are currently no Performance Demonstration Initiative (PDI) qualified single side examination procedures that demonstrate equivalency to two-sided examination procedures on austenitic piping welds. Current technology, is not capable of reliably detecting or sizing flaws on the far side of an austenitic weld for configurations common to United States nuclear applications. | There are currently no Performance Demonstration Initiative (PDI) qualified single side examination procedures that demonstrate equivalency to two-sided examination procedures on austenitic piping welds. Current technology, is not capable of reliably detecting or sizing flaws on the far side of an austenitic weld for configurations common to United States nuclear applications. | ||
PDI Performance Demonstration Qualification Summary (PDQS) certificates for austenitic piping list the limitation that single side examination is performed on a best effort basis. The best effort qualification is provided in place of a complete single side qualification to demonstrate that the examiners qualification and the subsequent weld examination is based on application of the best available technology. | PDI Performance Demonstration Qualification Summary (PDQS) certificates for austenitic piping list the limitation that single side examination is performed on a best effort basis. The best effort qualification is provided in place of a complete single side qualification to demonstrate that the examiners qualification and the subsequent weld examination is based on application of the best available technology. | ||
When the examination area is limited to one side of an austenitic weld, examination coverage does not comply with 10 CFR 50.55a(b)(2)(xv)(A) and proficiency demonstrations do not comply with 10 CFR 50.55a(b)(2)(xvi)(B) and full coverage credit may not be claimed.Based on the configuration limited to single side access, relief is requested from the essentially 100 percent surface examination coverage requirements for the subject piping welds listed in Table 1. Note that examination coverage listed is that attained during examination with no credit taken for the far side of each weld in which examination from that side could not be performed. | When the examination area is limited to one side of an austenitic weld, examination coverage does not comply with 10 CFR 50.55a(b)(2)(xv)(A) and proficiency demonstrations do not comply with 10 CFR 50.55a(b)(2)(xvi)(B) and full coverage credit may not be claimed. | ||
Pursuant to 10 CFR 50.55a(g)(5)(iii), relief is requested from the essentially 100 percent volumetric examination coverage requirement for the subject welds due to the geometric configuration and permanent obstructions which limit the volumetric examination coverage of the subject welds.The limitations and the actual examination coverage attained for each weld for which relief is requested are noted in Table 1. | Based on the configuration limited to single side access, relief is requested from the essentially 100 percent surface examination coverage requirements for the subject piping welds listed in Table 1. Note that examination coverage listed is that attained during examination with no credit taken for the far side of each weld in which examination from that side could not be performed. | ||
Pursuant to 10 CFR 50.55a(g)(5)(iii), relief is requested from the essentially 100 percent volumetric examination coverage requirement for the subject welds due to the geometric configuration and permanent obstructions which limit the volumetric examination coverage of the subject welds. | |||
: 6. Proposed Alternative and Basis for Use The subject welds received a volumetric examination to the maximum extent practical utilizing the best available techniques, as qualified through the Performance Demonstration Initiative (PDI) for Supplement 2 with demonstrated best effort for single sided examination, from the accessible side of the weld. Additionally, a surface examination without limitations was performed on each weld. Further, a visual (VT-2) examination is performed each inspection period during the system leakage tests as required by Section XI, Table IWC-2500-1, Category C-H.Based upon the examination volumes that were obtained with acceptable results along with the completed surface examination and the visual (VT-2) examination performed each inspection period, it is reasonable to conclude that service induced degradation would be detected if present. Therefore, these proposed alternatives provide an acceptable level of quality and safety by providing reasonable assurance of structural integrity of the subject welds.7. Period for Which Relief is Requested The relief is requested for the Third 10-year inspection interval for Donald C. Cook Nuclear Plant Units 1 and 2, which began on July 1, 1996, and ended April 9, 2010, at the conclusion of the Unit 1 Cycle 23 Refueling Outage. Significant long-term outages (greater than six months) occurred multiple times during the interval and the interval was extended as allowed by IWA-2430(e) and by IWA-2430(d) to accommodate interval planning and scheduling. | The limitations and the actual examination coverage attained for each weld for which relief is requested are noted in Table 1. | ||
to AEP-NRC-2012-2 Page 53 | |||
The flange side is limited by the O.D. contour and flange bolting. No relevant indications detected.The completed examination was limited to 50%coverage due to the configuration. | : 5. Burden Caused by Compliance Compliance with code requirements requires extensive modification or replacement of components with a design that allows examination from both sides of the weld. This option to meet the required 100 percent volume examination coverage is considered impractical based on the cost, additional radiation exposure and impact to plant equipment. | ||
The configuration 1 50.O/Y prevents examination from the pump side due to its severe taper and the proximity of the pump casing to the weld. No relevant indications detected.The completed examination was limited to 78%coverage due to the configuration. | : 6. Proposed Alternative and Basis for Use The subject welds received a volumetric examination to the maximum extent practical utilizing the best available techniques, as qualified through the Performance Demonstration Initiative (PDI) for Supplement 2 with demonstrated best effort for single sided examination, from the accessible side of the weld. Additionally, a surface examination without limitations was performed on each weld. Further, a visual (VT-2) examination is performed each inspection period during the system leakage tests as required by Section XI, Table IWC-2500-1, Category C-H. | ||
The configuration 1 78.O/Y prevents examination due to the welds location inside of the box restraint surrounding the pipe. No relevant indications detected.The completed examination was limited to 50%coverage due to the configuration. | Based upon the examination volumes that were obtained with acceptable results along with the completed surface examination and the visual (VT-2) examination performed each inspection period, it is reasonable to conclude that service induced degradation would be detected if present. Therefore, these proposed alternatives provide an acceptable level of quality and safety by providing reasonable assurance of structural integrity of the subject welds. | ||
The configuration 1 50.O/Y prevents examination on the tee side due to the sharp bevel adjacent to the tee side weld toe. No relevant indications detected.The completed examination was limited to 50%coverage due to the configuration. | : 7. Period for Which Relief is Requested The relief is requested for the Third 10-year inspection interval for Donald C. Cook Nuclear Plant Units 1 and 2, which began on July 1, 1996, and ended April 9, 2010, at the conclusion of the Unit 1 Cycle 23 Refueling Outage. Significant long-term outages (greater than six months) occurred multiple times during the interval and the interval was extended as allowed by IWA-2430(e) and by IWA-2430(d) to accommodate interval planning and scheduling. | ||
The examination 1 50.0/Y limitation is caused by the OD bevel on the valve, which is in proximity to the weld toe on the valve side.No relevant indications detected. | to AEP-NRC-2012-2 Page 54 Table 1 to Relief Request ISIR-41 Ultrasonic Examination ier Coverage Attained Remarks PDI (Y/N) | ||
The completed examination was limited to 50% | |||
Full coverage was 1 1-SI-34-1 1F Elbow to Valve C5.11 50.0/h not obtainable due to the bevel at the weld toe on the valve side of the weld. No relevant indications detected.The completed examination was limited to 50%2-(3TS coverage due to the configuration. | 1 50.0ON coverage due to the configuration. The flange side is limited by the O.D. contour and flange bolting. No relevant indications detected. | ||
The configuration 2 04F Pipe to Valve 05.11 50.0/Y prevents examination from the valve side due to its severe taper and close proximity of the valve to the weld. No relevant indications detected.The completed examination was limited to 50%coverage due to the configuration. | The completed examination was limited to 50% | ||
The configuration 1-SI-1i1A-Flange to Elbow C5.21 50.0/ of the reducing elbow to flange leads to a limited 01S examination based on the taper of the flange face and its proximity to the weld. No relevant indications detected.The completed examination was limited to 50%coverage due to the configuration. | coverage due to the configuration. The configuration 1 50.O/Y prevents examination from the pump side due to its severe taper and the proximity of the pump casing to the weld. No relevant indications detected. | ||
The configuration 1 1-SI-1 1-01S Flange to Elbow C5.21 50./Y of the elbow to flange leads to a limited examination based on the taper of the flange face and its proximity to the weld. No relevant indications detected.The completed examination was limited to 49%coverage due to the configuration. | The completed examination was limited to 78% | ||
The configuration prevents examination from the valve side due to its 1 1-SI-1 1-05F Pipe to Valve C5.21 49.0/Y severe taper and the close proximity of the valve. A portion of the pipe side is obstructed due to the proximity of the integrally welded pipe support. No relevant indications detected. | coverage due to the configuration. The configuration 1 78.O/Y prevents examination due to the welds location inside of the box restraint surrounding the pipe. No relevant indications detected. | ||
The completed examination was limited to 50% | |||
The configuration 1-SI-74-01F Elbow C5.21 50.0/Y prevents examination from the penetration side due to the OD surface contour and the proximity of the penetration. | coverage due to the configuration. The configuration 1 50.O/Y prevents examination on the tee side due to the sharp bevel adjacent to the tee side weld toe. No relevant indications detected. | ||
No relevant indications detected.The completed examination was limited to 50%coverage due to the configuration. | The completed examination was limited to 50% | ||
The configuration 2 2-SI-42-01S Flange to Elbow C5.21 50.0/Y prevents examination from the flange side due to its severe taper and close proximity of the flange taper to the weld. No relevant indications detected.The completed examination was limited to 46.5%coverage due to the configuration. | coverage due to the configuration. The examination 1 50.0/Y limitation is caused by the OD bevel on the valve, which is in proximity to the weld toe on the valve side. | ||
The configuration prevents examination from the valve side due to its 2 2-SI-42-03F Pipe to Valve C5.21 46.5/Y severe taper and close proximity of the valve to the weld. Additionally, a portion of the examination area was obstructed due to a branch connection in the piping. No relevant indications detected.The completed examination was limited to 50%coverage due to the configuration. | No relevant indications detected. | ||
The configuration 2 2-SI-73-02S Elbow to Pipe C5.21 50.0/Y prevents examination from the elbow side due to its severe taper and close proximity of the elbow to the weld. No relevant indications detected.The completed examination was limited to 50%coverage due to the configuration. | to AEP-NRC-2012-2 Page 55 Ultrasonic Examination Remarks CNP Component Weld Item Coverage Attained Unit ID Description Number (%)i PDI (YIN) | ||
The configuration 2 2-SI-81-01F Valve to Elbow C5.21 50.0/Y prevents examination from the valve side due to its severe taper and close proximity of the valve to the weld. No relevant indications detected. | The completed examination was limited to 50% | ||
coverage due to the configuration. Full coverage was 1 1-SI-34-1 1F Elbow to Valve C5.11 50.0/h not obtainable due to the bevel at the weld toe on the valve side of the weld. No relevant indications detected. | |||
The completed examination was limited to 50% | |||
2-(3TS coverage due to the configuration. The configuration 2 04F Pipe to Valve 05.11 50.0/Y prevents examination from the valve side due to its severe taper and close proximity of the valve to the weld. No relevant indications detected. | |||
The completed examination was limited to 50% | |||
coverage due to the configuration. The configuration 1-SI-1i1A- Flange to Elbow C5.21 50.0/ of the reducing elbow to flange leads to a limited 01S examination based on the taper of the flange face and its proximity to the weld. No relevant indications detected. | |||
The completed examination was limited to 50% | |||
coverage due to the configuration. The configuration 1 1-SI-1 1-01S Flange to Elbow C5.21 50./Y of the elbow to flange leads to a limited examination based on the taper of the flange face and its proximity to the weld. No relevant indications detected. | |||
The completed examination was limited to 49% | |||
coverage due to the configuration. The configuration prevents examination from the valve side due to its 1 1-SI-1 1-05F Pipe to Valve C5.21 49.0/Y severe taper and the close proximity of the valve. A portion of the pipe side is obstructed due to the proximity of the integrally welded pipe support. No relevant indications detected. | |||
to AEP-NRC-2012-2 Page 56 Ultrasonic CNP Component Weld Item Examination Unit ID Description Number Coverage Attained Remarks PDI (Y/N) | |||
The completed examination was limited to 50% | |||
Penetration to coverage due to the configuration. The configuration 1-SI-74-01F Elbow C5.21 50.0/Y prevents examination from the penetration side due to the OD surface contour and the proximity of the penetration. No relevant indications detected. | |||
The completed examination was limited to 50% | |||
coverage due to the configuration. The configuration 2 2-SI-42-01S Flange to Elbow C5.21 50.0/Y prevents examination from the flange side due to its severe taper and close proximity of the flange taper to the weld. No relevant indications detected. | |||
The completed examination was limited to 46.5% | |||
coverage due to the configuration. The configuration prevents examination from the valve side due to its 2 2-SI-42-03F Pipe to Valve C5.21 46.5/Y severe taper and close proximity of the valve to the weld. Additionally, a portion of the examination area was obstructed due to a branch connection in the piping. No relevant indications detected. | |||
The completed examination was limited to 50% | |||
coverage due to the configuration. The configuration 2 2-SI-73-02S Elbow to Pipe C5.21 50.0/Y prevents examination from the elbow side due to its severe taper and close proximity of the elbow to the weld. No relevant indications detected. | |||
The completed examination was limited to 50% | |||
coverage due to the configuration. The configuration 2 2-SI-81-01F Valve to Elbow C5.21 50.0/Y prevents examination from the valve side due to its severe taper and close proximity of the valve to the weld. No relevant indications detected. | |||
to AEP-NRC-2012-2 Page 57 RELIEF REQUEST ISIR-41 EXAMINATION CATEGORY C-F-1 PRESSURE RETAINING WELDS IN AUSTENITIC STAINLESS STEEL OR HIGH ALLOY PIPING SUPPORTING DOCUMENTATION IS PROVIDED BY I&M LETTER DATED APRIL 8, 2011 ADAMS ACCESSION NO. ML11110A042 AND THE FOLLOWING PAGE to AEP-NRC-2012-2 Page 58 1-SI-24-06F 1-SI-1 52N Pipe to Tee Check Valve Weld Location Sketch for 1-SI-24-06F to AEP-NRC-2012-2 Page 59 RELIEF REQUEST ISIR-42 | |||
. EXAMINATION CATEGORY R-A RISK INFORMED PIPING EXAMINATIONS to AEP-NRC-2012-2 Page 60 RELIEF REQUEST ISIR-42 Relief Request In Accordance with 10 CFR 50.55a(g)(5)(iii) | |||
Inservice Inspection Impracticality | Inservice Inspection Impracticality | ||
: 1. ASME Code Components Affected ASME Code Class: Code Class 1 and 2 Examination Category: | : 1. ASME Code Components Affected ASME Code Class: Code Class 1 and 2 Examination Category: R-A, Risk Informed Piping Examinations Item Numbers: R1. 11, Elements Subject to Thermal Fatigue R1.16, Elements Subject to Intergranular or Transgranular Stress Corrosion Cracking (IGSCC or TGSCC) | ||
R-A, Risk Informed Piping Examinations Item Numbers: R1. 11, Elements Subject to Thermal Fatigue R1.16, Elements Subject to Intergranular or Transgranular Stress Corrosion Cracking (IGSCC or TGSCC)R1.20, Elements Not Subject to a Degradation Mechanism Component Identification: | R1.20, Elements Not Subject to a Degradation Mechanism Component Identification: Listed in Table 1 | ||
Listed in Table 1 2. Applicable Code Edition and Addenda ASME Section Xl, 1989 Edition, No addenda Austenitic piping welds with single side access subject to ultrasonic examination with Supplement 2 of Appendix VIII to the 1995 Edition with 1996 Addenda of ASME Section XI.3. Applicable Code Requirement The examination requirements for Class 1 and 2 piping welds are governed by the Risk Informed Inservice Inspection program that was approved by the NRC in a Safety Evaluation Report dated September 28, 2007 (ADAMS Accession No. ML072620553). | |||
This program was developed in accordance with ASME Section Xl Code Case N-716, Alternative Piping Classification and Examination Requirements. | ===2. Applicable Code Edition and Addenda=== | ||
Table 1, Examination Category R-A, of Code Case N-716 requires 100 percent of the examination location to be examined. | ASME Section Xl, 1989 Edition, No addenda Austenitic piping welds with single side access subject to ultrasonic examination with Supplement 2 of Appendix VIII to the 1995 Edition with 1996 Addenda of ASME Section XI. | ||
The alternative requirements of ASME Section Xl, Code Case N-460, approved for use in Regulatory Guide 1.147, Revision 15, allow credit for essentially 100 percent coverage of the weld provided greater than 90 percent of the required volume has been examined.10 CFR 50.55a(b)(2)(xv)(A), requires the following examination coverage when applying Supplement 2 to Appendix VIII: (1) Piping must be examined in two axial directions and when examination in the circumferential direction is required, the circumferential examination must be performed in two directions, provided access is available. | |||
(2) Where examination from both sides is not possible, full coverage credit may be claimed from a single side for ferritic welds. Where examination from both sides is not possible on austenitic welds, full coverage credit from a single side may be claimed only | ===3. Applicable Code Requirement=== | ||
To demonstrate equivalency to the two sided examinations, the demonstration must be performed to the requirements of Appendix VIII as modified by this paragraph and 10 CFR 50.55a(b)(2)(xv)(A). | The examination requirements for Class 1 and 2 piping welds are governed by the Risk Informed Inservice Inspection program that was approved by the NRC in a Safety Evaluation Report dated September 28, 2007 (ADAMS Accession No. ML072620553). This program was developed in accordance with ASME Section Xl Code Case N-716, Alternative Piping Classification and Examination Requirements. Table 1, Examination Category R-A, of Code Case N-716 requires 100 percent of the examination location to be examined. The alternative requirements of ASME Section Xl, Code Case N-460, approved for use in Regulatory Guide 1.147, Revision 15, allow credit for essentially 100 percent coverage of the weld provided greater than 90 percent of the required volume has been examined. | ||
: 4. Impracticality of Compliance Pursuant to 10 CFR 50.55a(g)(5)(iii), relief is requested from the 100 percent volumetric examination coverage requirement for austenitic piping welds with single side access.There are currently no Performance Demonstration Initiative (PDI) qualified single side examination procedures that demonstrate equivalency to two-sided examination procedures on austenitic piping welds. Current technology is not capable of reliably detecting or sizing flaws on the far side of an austenitic weld for configurations common to United States nuclear applications. | 10 CFR 50.55a(b)(2)(xv)(A), requires the following examination coverage when applying Supplement 2 to Appendix VIII: | ||
(1) Piping must be examined in two axial directions and when examination in the circumferential direction is required, the circumferential examination must be performed in two directions, provided access is available. | |||
(2) Where examination from both sides is not possible, full coverage credit may be claimed from a single side for ferritic welds. Where examination from both sides is not possible on austenitic welds, full coverage credit from a single side may be claimed only to AEP-NRC-2012-2 Page 61 after completing a successful single side Appendix VIII demonstration using flaws on the opposite side of the weld. | |||
10 CFR 50.55a(b)(2)(xvi)(B), requires that examinations performed from one side of a stainless steel pipe weld must be conducted with equipment, procedures, and personnel that have demonstrated proficiency with single side examinations. To demonstrate equivalency to the two sided examinations, the demonstration must be performed to the requirements of Appendix VIII as modified by this paragraph and 10 CFR 50.55a(b)(2)(xv)(A). | |||
: 4. Impracticality of Compliance Pursuant to 10 CFR 50.55a(g)(5)(iii), relief is requested from the 100 percent volumetric examination coverage requirement for austenitic piping welds with single side access. | |||
There are currently no Performance Demonstration Initiative (PDI) qualified single side examination procedures that demonstrate equivalency to two-sided examination procedures on austenitic piping welds. Current technology is not capable of reliably detecting or sizing flaws on the far side of an austenitic weld for configurations common to United States nuclear applications. | |||
PDI Performance Demonstration Qualification Summary (PDQS) certificates for austenitic piping list the limitation that single side examination is performed on a best effort basis. The best effort qualification is provided in place of a complete single side qualification to demonstrate that the examiners qualification and the subsequent weld examination is based on application of the best available technology. | PDI Performance Demonstration Qualification Summary (PDQS) certificates for austenitic piping list the limitation that single side examination is performed on a best effort basis. The best effort qualification is provided in place of a complete single side qualification to demonstrate that the examiners qualification and the subsequent weld examination is based on application of the best available technology. | ||
When the examination area is limited to one side of an austenitic weld, examination coverage does not comply with 10 CFR 50.55a(b)(2)(xv)(A) and proficiency demonstrations do not comply with 10 CFR 50.55a(b)(2)(xvi)(B) and full coverage credit may not be claimed.Based on the configuration limited to single side access, relief is requested on complying with the 100 percent required examination coverage for the piping welds listed in Table 1. Note that examination coverage listed is that which was obtained during examination with no credit taken for the far side of each weld when only single-sided access was attainable. | When the examination area is limited to one side of an austenitic weld, examination coverage does not comply with 10 CFR 50.55a(b)(2)(xv)(A) and proficiency demonstrations do not comply with 10 CFR 50.55a(b)(2)(xvi)(B) and full coverage credit may not be claimed. | ||
Other welds in Table 1 have physical limitations that prevented full access from both sides of the weld. These limitations include pipe support members, transition areas on elbows, tapers and other geometric interferences. | Based on the configuration limited to single side access, relief is requested on complying with the 100 percent required examination coverage for the piping welds listed in Table 1. Note that examination coverage listed is that which was obtained during examination with no credit taken for the far side of each weld when only single-sided access was attainable. | ||
Compliance with code requirements would require extensive modification or replacement of components with a design that allows examination from both sides of the weld.5. Burden Caused by Compliance Compliance with code requirements requires extensive modification or replacement of components with a design that allows examination from both sides of the weld.This option to meet the required 100 percent volume examination coverage is considered impractical based on the cost, additional radiation exposure and impact to plant equipment | Other welds in Table 1 have physical limitations that prevented full access from both sides of the weld. These limitations include pipe support members, transition areas on elbows, tapers and other geometric interferences. Compliance with code requirements would require extensive modification or replacement of components with a design that allows examination from both sides of the weld. | ||
: 5. Burden Caused by Compliance Compliance with code requirements requires extensive modification or replacement of components with a design that allows examination from both sides of the weld. | |||
The exam 50.O0Y limitation was due to the geometry of the branch limiting access from the downstream side. No relevant indications detected.The completed examination was limited to 50%coverage due to the configuration. | This option to meet the required 100 percent volume examination coverage is considered impractical based on the cost, additional radiation exposure and impact to plant equipment to AEP-NRC-2012-2 Page 62 | ||
The configuration 50.O0Y prevents examination on the tee side, downstream, due to the sharp bevel adjacent to the tee side weld toe. No relevant indications detected.The completed examination was limited to 50%coverage due to the configuration. | : 6. Proposed Alternative and Basis for Use The subject welds received a volumetric examination to the maximum extent practical utilizing the best available techniques, as qualified through the Performance Demonstration Initiative (PDI) for Supplement 2 with demonstrated best effort for single sided examination, from the accessible side of the weld. Additionally, a surface examination without limitations was performed on each weld. Further, a visual (VT-2) examination is performed each inspection period during the system leakage tests as required by Section Xl, Table IWC-2500-1, Category C-H. | ||
The configuration 50.0/Y prevents examination on the tee side due to the sharp bevel adjacent to the tee side weld toe. No relevant indications detected.The completed examination was limited to 50%coverage due to the configuration. | Based upon the examination volumes that were obtained with acceptable results along with the completed surface examination and the visual (VT-2) examination performed each inspection period, it is reasonable to conclude that service induced degradation would be detected if present. Therefore, these proposed alternatives provide an acceptable level of quality and safety by providing reasonable assurance of structural integrity of the subject welds. | ||
The configuration 50.O0Y prevents examination on the tee side due to the sharp bevel adjacent to the tee side weld toe. No relevant indications detected.The completed examination was limited to 50%coverage due to the configuration. | : 7. Period for Which Relief is Requested The relief is requested for the Third 10-year inspection interval for Donald C. Cook Nuclear Plant Units 1 and 2, which began on July 1, 1996, and ended April 9, 2010, at the conclusion of the Unit 1 Cycle 23 Refueling Outage. Significant long-term outages (greater than six months) occurred multiple times during the interval and the interval was extended as allowed by IWA-2430(e) and by IWA-2430(d) to accommodate interval planning and scheduling. | ||
The configuration 50.0/Y prevents examination on the tee side due to the sharp bevel adjacent to the tee side weld toe. No relevant indications detected. | to AEP-NRC-2012-2 Page 63 Table 1 to Relief Request ISIR-42 Coverage Attained (%)I Remarks PDI (Y/N) | ||
The completed examination was limited to 50% | |||
The configuration 2-SI-57-19 prevents examination on the tee side due to the sharp 2 (Class 1) Pipe to Tee R1.16 36.8/Y bevel adjacent to the tee side weld toe (single side exam = 50.0%). Additional coverage was missed due to the weld contour (13.2%). No relevant indications detected.The completed examination was limited to 50.0%2-SI-57-21 coverage due to the configuration. | coverage due to the configuration. The exam 50.O0Y limitation was due to the geometry of the branch limiting access from the downstream side. No relevant indications detected. | ||
The configuration 2 (Class 1) Elbow to Tee RI. 16 50.0/Y prevents examination on the tee side due to the sharp bevel adjacent to the tee side weld toe (single side exam = 50.0%). No relevant indications detected.The completed examination was limited to 50.0%2-SI-56-18 coverage due to the configuration. | The completed examination was limited to 50% | ||
The configuration 2 (Class 1 ) Elbow to Tee RI. 16 50.0/Y prevents examination on the tee side due to the sharp bevel adjacent to the tee side weld toe (single side exam = 50.0%). No relevant indications detected.The completed examination was limited to 50%1-SI-548-coverage due to the configuration. | coverage due to the configuration. The configuration 50.O0Y prevents examination on the tee side, downstream, due to the sharp bevel adjacent to the tee side weld toe. No relevant indications detected. | ||
Full coverage was 1 45S (Class Valve to Pipe R1.20 50.0/Y not obtainable due to the bevel at the weld toe on the 1) valve side of the weld. No relevant indications detected.The completed examination was limited to 50%1-RH Elbow to coverage due to the configuration. | The completed examination was limited to 50% | ||
Full coverage was 1 06F (Class Valve R1.20 50.0/ not obtainable due to the bevel at the weld toe on the 2) valve side of the weld. No relevant indications detected. | coverage due to the configuration. The configuration 50.0/Y prevents examination on the tee side due to the sharp bevel adjacent to the tee side weld toe. No relevant indications detected. | ||
The completed examination was limited to 50% | |||
Full coverage was S (Class 1) Elbow to Pipe R1.20 89.7NY not obtainable due to the bevel at the weld toe on the valve side of the weld. No relevant indications detected.The completed examination was limited to 50%1-SI-29-26F coverage due to the configuration. | coverage due to the configuration. The configuration 50.O0Y prevents examination on the tee side due to the sharp bevel adjacent to the tee side weld toe. No relevant indications detected. | ||
Full coverage was I (Class 1) Elbow to Pipe R1.20 50.O/Y not | The completed examination was limited to 50% | ||
Full coverage was (Class 1) Elbow not obtainable due to the Nozzle taper at the weld toe.No relevant indications detected.The completed examination was limited to 50%2-RC-22-24 Elbow to coverage due to the configuration. | coverage due to the configuration. The configuration 50.0/Y prevents examination on the tee side due to the sharp bevel adjacent to the tee side weld toe. No relevant indications detected. | ||
The configuration 2 (Class 1) Valve R1.20 50.0/Y prevents examination from the valve side due to the close proximity of the valve body to the weld. No relevant indications detected.The completed examination was limited to 50%2-RC-23-12 Elbow to coverage due to the configuration. | to AEP-NRC-2012-2 Page 64 CNP Component Weld Item Ultrasonic Examination ID Description Number Coverage Attained (%)I Remarks Unit PDI (Y/N) | ||
The configuration 2 (Class 1) Valve R1.20 50.O/Y prevents examination from the valve side due to the close proximity of the valve body to the weld. No relevant indications detected.The completed examination was limited to 50%2-RC-24-09 Elbow to coverage due to the configuration. | The completed examination was limited to 36.8% | ||
The configuration 2 (Class 1) Valve R1.20 50.0Y prevents examination from the valve side due to the close proximity of the valve body to the weld. No relevant indications detected. | coverage due to the configuration. The configuration 2-SI-57-19 prevents examination on the tee side due to the sharp 2 (Class 1) Pipe to Tee R1.16 36.8/Y bevel adjacent to the tee side weld toe (single side exam = 50.0%). Additional coverage was missed due to the weld contour (13.2%). No relevant indications detected. | ||
The completed examination was limited to 50.0% | |||
The configuration 12 prevents examination from the Socket Welded fitting side. No relevant indications detected.2-SI-569-The completed examination was limited to 50%2 53S (Class Elbow to Pipe R1.20 50.0/ coverage due to the configuration. | 2-SI-57-21 coverage due to the configuration. The configuration 2 (Class 1) Elbow to Tee RI. 16 50.0/Y prevents examination on the tee side due to the sharp bevel adjacent to the tee side weld toe (single side exam = 50.0%). No relevant indications detected. | ||
The configuration | The completed examination was limited to 50.0% | ||
: 1) prevents examination from the Socket Welded fitting side. No relevant indications detected.2-SI-569-The completed examination was limited to 50%2 54S (Class Elbow to Pipe R1.20 50.O0Y coverage due to the configuration. | 2-SI-56-18 coverage due to the configuration. The configuration 2 (Class 1 ) Elbow to Tee RI. 16 50.0/Y prevents examination on the tee side due to the sharp bevel adjacent to the tee side weld toe (single side exam = 50.0%). No relevant indications detected. | ||
The configuration prevents examination from the Socket Welded fitting 1) side. No relevant indications detected.The completed examination was limited to 48.4%coverage due to the configuration. | The completed examination was limited to 50% | ||
The configuration 2-SI-57-22 prevents examination on the tee side due to the sharp 2 (Class 1) Tee to Pipe R1.16 48.4/Y bevel adjacent to the tee side weld toe (single side exam = 50.0%). Additional coverage was missed due to the weld contour (1.6%). No relevant indications detected.The completed examination was limited to 66.2%2-SI-56-10 coverage due to the configuration. | 1-SI-548- coverage due to the configuration. Full coverage was 1 45S (Class Valve to Pipe R1.20 50.0/Y not obtainable due to the bevel at the weld toe on the | ||
The configuration 2 (Class 1) Pipe to Elbow R1.20 66.2NY prevents examination of 100% of the required area due to the presence of. a permanent support which limited access. No relevant indications detected.The completed examination was limited to 50%2-SI-78-01 Valve to coverage due to the configuration. | : 1) valve side of the weld. No relevant indications detected. | ||
The configuration 2 (Class 1) Elbow R1.20 50.0K prevents examination from the valve side due to its severe taper and close proximity of the valve to the weld. No relevant indications detected. | The completed examination was limited to 50% | ||
1-RH Elbow to coverage due to the configuration. Full coverage was 1 06F (Class Valve R1.20 50.0/ not obtainable due to the bevel at the weld toe on the | |||
The exam 2 (Class 1) Branch R1.20 50.0/Y limitation was due to the geometry of the branch limiting access from the upstream side. No relevant indications detected. | : 2) valve side of the weld. No relevant indications detected. | ||
to AEP-NRC-2012-2 Page 65 CNP Component Weld CNP Wel Item ompnen Itm Ultrasonic Examination Cverge Ataied %)/Remarks Unit ID Description Number Coverage Attained (N)I PDI (YIN) | |||
The completed examination was limited to 89.7% | |||
1-RC-8-02S coverage due to the configuration. Full coverage was S (Class 1) Elbow to Pipe R1.20 89.7NY not obtainable due to the bevel at the weld toe on the valve side of the weld. No relevant indications detected. | |||
The completed examination was limited to 50% | |||
1-SI-29-26F coverage due to the configuration. Full coverage was I (Class 1) Elbow to Pipe R1.20 50.O/Y not valveobtainable side of due the toweld. | |||
the bevel at the weld toe on the No relevant indications detected. | |||
The completed examination was limited to 50% | |||
1-SI-33-26F Nozzle to R1.20 50.0/ coverage due to the configuration. Full coverage was (Class 1) Elbow not obtainable due to the Nozzle taper at the weld toe. | |||
No relevant indications detected. | |||
The completed examination was limited to 50% | |||
2-RC-22-24 Elbow to coverage due to the configuration. The configuration 2 (Class 1) Valve R1.20 50.0/Y prevents examination from the valve side due to the close proximity of the valve body to the weld. No relevant indications detected. | |||
The completed examination was limited to 50% | |||
2-RC-23-12 Elbow to coverage due to the configuration. The configuration 2 (Class 1) Valve R1.20 50.O/Y prevents examination from the valve side due to the close proximity of the valve body to the weld. No relevant indications detected. | |||
The completed examination was limited to 50% | |||
2-RC-24-09 Elbow to coverage due to the configuration. The configuration 2 (Class 1) Valve R1.20 50.0Y prevents examination from the valve side due to the close proximity of the valve body to the weld. No relevant indications detected. | |||
to AEP-NRC-2012-2 Page 66 Item Ultrasonic Co nic Examination Exainatior CNP Component Weld Unit ID Description Number overage Attained)Remarks PDI (YIN) 2-SI-569- The completed examination was limited to 50% | |||
2 49S (Class Tee to Pipe R1.20 50.0/N coverage due to the configuration. The configuration 12 prevents examination from the Socket Welded fitting side. No relevant indications detected. | |||
2-SI-569- The completed examination was limited to 50% | |||
2 53S (Class Elbow to Pipe R1.20 50.0/ coverage due to the configuration. The configuration | |||
: 1) prevents examination from the Socket Welded fitting side. No relevant indications detected. | |||
2-SI-569- The completed examination was limited to 50% | |||
2 54S (Class Elbow to Pipe R1.20 50.O0Y coverage due to the configuration. The configuration prevents examination from the Socket Welded fitting | |||
: 1) side. No relevant indications detected. | |||
The completed examination was limited to 48.4% | |||
coverage due to the configuration. The configuration 2-SI-57-22 prevents examination on the tee side due to the sharp 2 (Class 1) Tee to Pipe R1.16 48.4/Y bevel adjacent to the tee side weld toe (single side exam = 50.0%). Additional coverage was missed due to the weld contour (1.6%). No relevant indications detected. | |||
The completed examination was limited to 66.2% | |||
2-SI-56-10 coverage due to the configuration. The configuration 2 (Class 1) Pipe to Elbow R1.20 66.2NY prevents examination of 100% of the required area due to the presence of. a permanent support which limited access. No relevant indications detected. | |||
The completed examination was limited to 50% | |||
2-SI-78-01 Valve to coverage due to the configuration. The configuration 2 (Class 1) Elbow R1.20 50.0K prevents examination from the valve side due to its severe taper and close proximity of the valve to the weld. No relevant indications detected. | |||
to AEP-NRC-2012-2 Page 67 Ultrasonic Examination a CNP Component Weld Item Covrage ExainatiR Unit ID Description Number Coverage Attained Remarks PDI (Y/N) | |||
The completed examination was limited to 50% | |||
2-SI-56-22 Elbow to coverage due to the configuration. The exam 2 (Class 1) Branch R1.20 50.0/Y limitation was due to the geometry of the branch limiting access from the upstream side. No relevant indications detected. | |||
to AEP-NRC-2012-2 Page 68 RELIEF REQUEST ISIR-42 EXAMINATION CATEGORY R-A RISK INFORMED PIPING EXAMINATIONS SUPPORTING DOCUMENTATION IS PROVIDED BY I&M LETTER DATED APRIL 8, 2011 ADAMS ACCESSION NO. ML1111OA042 AND THE FOLLOWING THREE PAGES to AEP-NRC-2012-2 Page 69 (REF) | |||
'. ý" Iýr .- I-to AEP-NRC-2012-2 Page 70 SUPPORT 2-GRC-S6e3 ON ELBOW - | |||
(REF) | |||
(REF) 3" SCH. | |||
160 SMLS. | |||
S. S PIPE DETAIL "B" LOOKING EAST Location of Elbow to Valve Weld 2-RC-23-12 to AEP-NRC-2012-2 Page 71 7 | |||
N, I I I I I I I A | |||
Ad. | |||
Location of Elbow to Valve Weld 2-RC-24-09}} |
Latest revision as of 17:16, 6 February 2020
ML12076A027 | |
Person / Time | |
---|---|
Site: | Cook |
Issue date: | 03/06/2012 |
From: | Gebbie J Indiana Michigan Power Co |
To: | Document Control Desk, Office of Nuclear Reactor Regulation |
References | |
AEP-NRC-2012-2 | |
Download: ML12076A027 (86) | |
Text
z INDIANA MICHIGAN Indiana Michigan Power POWER* One Cook Place Bridgman, M149106 A unit ofAmerican ElectricPower Indiana MichiganPower.com March 6, 2012 AEP-NRC-2012-2 10 CFR 50.4 Docket Nos.: 50-315 50-316 U. S. Nuclear Regulatory Commission ATTN: Document Control Desk Washington, D. C. 20555-0001 Donald C. Cook Nuclear Plant Units 1 and 2 RELIEF REQUESTS FOR LIMITED COVERAGE INSPECTIONS RESPONSE TO REQUEST FOR ADDITIONAL INFORMATION
References:
- 1. Letter from J. P. Gebbie, Indiana Michigan Power Company, to U. S. Nuclear Regulatory Commission Document Control Desk, "Donald C. Cook Nuclear Plant Units 1 and 2, Relief Requests for Limited Coverage Examinations Performed in the Third 10-Year Inspection Interval," AEP-NRC-2011-23, dated April 8, 2011, Agencywide Documents Access and Management System (ADAMS) Accession No. ML11110A042
- 2. Memorandum from P. S. Tam, U. S. Nuclear Regulatory Commission, to H. L. Etheridge, Indiana Michigan Power Company, "D. C. Cook - Draft RAI on Proposed Relief Requests ISIR-33 thru ISIR-42 (TAC Nos. ME6087, ME6088)," October 21, 2011, ADAMS Accession No. ML112940700 By Reference 1, Indiana Michigan Power Company (I&M), the licensee for Donald C. Cook Nuclear Plant (CNP) Units 1 and 2, requested relief from American Society of Mechanical Engineers Boiler and Pressure Code requirements for various in-service inspection (ISI) activities on the basis that the required examination coverage is impractical due to physical obstructions and limitations imposed by design, geometry, and materials of construction of the subject components. By Reference 2, the NRC communicated a draft Request for Additional Information (RAI) to I&M for information needed to complete the relief request evaluation.
Via a teleconference on October 31, 2011, and e-mail exchanges with the NRC Licensing Project Manager on January 31 and February 14, 2012, a due date of March 7, 2012 was established.
U. S. Nuclear Regulatory Commission AEP-NRC-2012-2 Page 2 I&M's response to the RAI is provided as Enclosure 1 to this letter. A revised copy of Relief Requests (RR) ISIR-33 through ISIR-42, without the pages of the Supporting Documentation sections in the RRs provided in Reference 1, is provided as Enclosure 2 to assist in your review.
There are no new or revised regulatory commitments made as a part of this submittal. Should you have any questions, please contact Mr. Michael K. Scarpello, Regulatory Affairs Manager, at (269) 466-2649.
Sincerely, Joel P. Gebbie Site Vice President JRW/jen
Enclosures:
- 1. Response to Request for Additional Information
- 2. Revised Relief Requests ISIR-33 through ISIR-42 c: J. T. King, MPSC S. M. Krawec, AEP Ft. Wayne, w/o enclosures MDEQ - WHMD/RPS NRC Resident Inspector C. D. Pederson, NRC Region III P. S. Tam, NRC Washington, DC to AEP-NRC-2012-2 Page I RESPONSE TO REQUEST FOR ADDITIONAL INFORMATION FOR RELIEF REQUESTS FOR LIMITED COVERAGE EXAMINATION RELIEF REQUESTS ISIR-33 THROUGH ISIR 42
References:
- 1. Letter from J. P. Gebbie, Indiana Michigan Power Company, to U. S. Nuclear Regulatory Commission Document Control Desk, "Donald C. Cook Nuclear Plant Units 1 and 2, Relief Requests for Limited Coverage Examinations Performed in the Third 10-Year Inspection Interval," AEP-NRC-2011-23, dated April 8, 2011, Agencywide Documents Access and Management System (ADAMS) Accession Number ML11110A042 By Reference 1, Indiana Michigan Power Company (I&M), the licensee for Donald C. Cook Nuclear Plant (CNP) Units 1 and 2, submitted Requests for Relief, ISIR-33 thru ISIR-42, from the requirements of the American Society of Mechanical Engineers (ASME) Boiler and Pressure Vessel Code, Section Xl, for CNP Units 1 and 2. The requests for relief apply to the third 10-year inservice inspection interval, in which I&M adopted the 1989 Edition with no Addenda of ASME Code Section Xl as the Code of Record.
The NRC staff reviewed the submitted information and determined that additional information was needed to complete the evaluation. I&M's response to the request for additional information (RAI) is provided below. As a separate enclosure to this letter (Enclosure 2), the revised Relief Requests (RRs) ISIR-33 through ISIR-42 are provided with the applicable information indicated in the I&M response below, with the exception of the pages of the Supporting Documentation sections in the RRs provided in Reference 1.
NRC Item I - Generic Questions for RRs ISIR-33 through ISIR-42 The licensee did not identify the request for relief that was requested for each CNP, Unit.
Designate the CNP Unit or Units for each request for relief.
Where both a surface examination and volumetric examinations were required by the ASME Code, provide the results of the surface examinations for each relief request, if it applies. State if any indications were identified.
State for each examination if ASME Code,Section XI, Appendix VIII methodology was used for the welds contained in RRs ISIR-34 through ISIR-42.
For RRs ISIR-33 through ISIR-42 state whether or not any indications were identified during the examinations. If any, state the disposition of the indications.
I&M Response to NRC Item 1 A new column was added to each Table 1 in RRs ISIR-33 through ISIR-42 to identify the applicable CNP unit.
to AEP-NRC-2012-2 Page 2 Examinations that required both a surface and volumetric examination are contained within RR ISIR-35 (component IDs 2-RC-26 and 2-RC-27 only), RR ISIR-36, and RR ISIR-37. These examinations are described in Section 6 of RR ISIR-35 (as revised), RR ISIR-36, and RR ISIR-37. There were no surface indications identified.
With the exception of ISIR-40, which is a relief request for less than 100% of the Surface Area, the column titled "Ultrasonic Examination Coverage Attained (%)" in Table 1 of each relief request was revised to indicate whether a PDI qualified examination was performed by adding "PDI (YIN)". Components examined using Appendix VIII methodology, as modified by the Performance Demonstration Initiative and 10 CFR 50.55a, are annotated with "Y". Those annotated with "N" have a parenthetical reference to the examination requirement.
For all relief requests, the column titled "Remarks" in Table 1 identifies if there were any indications and also provides the disposition.
NRC Item 2 - RR ISIR-33 ASME Code,Section XI, Examination Category B-A. Items B1.11, B1.12, B1.21, B1.22, and B1.30 Pressure Retaining Welds in Reactor Pressure Vessel and ASME Code,Section XI, Examination Category B-D, Item 3.90 Based on the limited descriptions and sketches provided in the submittal, it appears that examinations for ASME Code, Section, Xl, Table IWB 2500-1, Category B-A, Items B1.11, B1.12, B1.21, and B1.22 were performed from the inside surface of the reactor pressure vessel (RPV). State whether access to the subject welds from the outside of the RPV is possible, and discuss the potential for increasing ASME Code volumetric coverage by applying examinations from the outside surface of the RPV.
Discuss whether other welds in ASME Code,Section XI, Examination Category B-A have been examined to the full, ASME Code-required volumetric extent, whether any indications were found as a result of these examinations, and the final disposition of the indications.
I&M Response to NRC Item 2 Access to the exterior of the reactor vessel is not practical due to higher radiation exposure and limited access for personnel and equipment caused by the close proximity of building structures/concrete and installed insulation and insulation support members. Greater coverage is achieved via the inside surface and results in less radiation exposure to personnel.
Additionally, some of the same interferences that exist for examination from the inside of the vessel are also present on the outside of the vessel (such as the bottom mounted instrument penetrations). Therefore, I&M does not consider that additional volumetric coverage can be attained without significant additional radiation exposure and additional resources to modify existing structures to allow for access.
Twenty ASME Category B-A welds received examination during the Third ISI Interval. Ten had coverage greater than 90%. There were no indications in the twenty ASME Category B-A welds that were examined.
to AEP-NRC-2012-2 Page 3 NRC Item 3 - RR ISIR-36 ASME Code, Section Xl, Examination Category B-F Pressure Retaining Welds The difficulties on obtaining coverage in these welds seem to be caused by the use of fixed-angle probes with a limited area available for scanning. Provide a discussion on alternative examination methods and techniques such as phased-array ultrasonic (UT) techniques (line scan or raster) that cover many angles that can be used to obtain greater coverage for welds covered in ISIR-36 I&M Response to NRC Item 3 When these examinations were performed, Phased Array (PA) techniques were not yet qualified under the Performance Demonstration Initiative (PDI) and were therefore not available for use. Use of radiography would pose a significant hardship due to the impact on resources.
Radiography would require evacuation of containment during refueling outages for extended periods of time. Additionally, radiography has not been demonstrated as an equivalent technique to PDI qualified examinations.
NRC Item 4 - RR ISIR-37 ASME Code, Section Xl, Examination Category B-J Pressure Retaining Welds in Piping Identify the system(s), and nominal pipe diameters or components for welds 1-RH-28-05F, 1-SI-22-18F, 1-SI-23-17F, I-RC-5-011F, 1-SI-33-23S, 2-RC-22-01, and 2-RC-28-23.
State the material of construction of the piping, valves, and Tees. Identify the dissimilar metal welds, if any in Table I of RR ISIR-37.
I&M ResDonse to NRC Item 4 The table below provides the information requested above:
Weld ID System Nominal Pipe Materials DM Weld (Y/N)
Size (NPS) 1-RH-28-05F Residual Heat 14.0" NPS Both Stainless N Removal Steel Pipe to Pipe Type 316 1-SI-22-18F Safety Injection 6.0" NPS Both Stainless N Pipe to Valve Steel Type 316 to AEP-NRC-2012-2 Page 4 Weld ID System Nominal Pipe Materials DM Weld (Y/N)
Size (NPS) 1-SI-23-17F Safety Injection 6.0" NPS Both Stainless N Steel Pipe to valve Type 316 1-RC-5-01F Reactor 14.0" NPS Pipe Stainless N Coolant Steel Branch to Pipe Type 316 Branch -
SA-351 Grade CF8M 1-SI-33-23S Safety Injection 10.0" NPS Pipe - Stainless N Steel Tee to Pipe Type 316 Tee - SA-403 Grade WP 316 2-RC-22-01 Reactor 6.0" NPS Pipe Stainless N Coolant Steel Safe End to Elbow Type 316/ Safe End - SA-351 Grade CF8M 2-RC-28-23 Reactor 4.0" NPS Both Stainless N Coolant Steel Tee to Pipe Type 316 2-SI-56-19 Safety Injection 10.0" NPS Pipe and Tee N Stainless Steel Tee to Pipe Type 316 2-RH-33-01 Residual Heat 14.0" NPS Pipe and Tee N Removal Stainless Steel Tee to Pipe Type 316 to AEP-NRC-2012-2 Page 5 Weld ID System Nominal Pipe Materials DM Weld (Y/N)
Size (NPS) 2-RC-17-08N Reactor 27.5" Inside Branch: N Branch to Pipe Coolant Diameter to Stainless Steel 10.0" NPS WP 316 Pipe: Cast Austenitic Stainless Steel SA-351 Grade CF8M NRC Item 5 - RR ISIR-38 ASME Code, Section X1I Examination Category C-A Pressure Retaining Pressure Vessels Please submit detailed and specific information to support the bases for limited volumetric coverage in ASME Code,Section XI, Examination Category C-A components, and therefore, demonstrate impracticality.
a) As applicable, describe NDE equipment (UT scanning apparatus) and details of the listed obstructions (size, shape, proximity to the weld, etc.) to demonstrate accessibility limitations. Discuss whether alternative methods or advanced technologies could be employed to maximize ASME Code coverage.
b) Fully clarify the wave modality and insonification angles used for all ultrasonic examinations.
Please also state the materials of construction and the wall thickness for the Residual Heat Removal heat exchanger.
Identify the system(s) and component(s) for the welds contained in Table 1 of RR ISIR-38 I&M Response to NRC Item 5 Details and specific information for each limitation on each Component ID are contained in Table 1 and in the Supporting Documentation section of the RR submitted by Reference 1. The column titled "Remarks" in Table 1 of the RR provides a brief description of the limitation(s) for each component. The Supporting Documentation section for this RR provides details, in the form of Nondestructive Examination (NDE) datasheets, for each component of the area not scanned due to the limitation.
a) With the exception of STM-24-04, the NDE equipment used was standard manual ultrasonic scopes, transducers and wedges. STM-24-04 was examined using the vendor's Autoscan 2000 (an electro-mechanical track-guided system) equipment and the Micro-Tomoscan data acquisition system. When these examinations were performed, to AEP-NRC-2012-2 Page 6 no advanced ultrasonic or radiographic techniques were qualified for use; therefore, no alternative examinations were explored. An annotated picture has been added to RR ISIR-38, Supporting Documentation section, to provide additional detail of the obstructions for component W-CTSHEX. An annotated excerpt of a plant construction drawing has been added to RR ISIR-38, Supporting Documentation section, to provide additional detail of the obstructions for component 2-BIT-A. For component STM-24-04, there are no pictures or plant drawings available that can provide additional details of the obstructions beyond what has already been provided in RR ISIR-38 by Reference 1.
b) A summary of the wave modality and insonification angles are provided in the table below.
Component ID Insonification Angle Wave Mode*
W-CTSHEX 00 L, 450 S, 600 L 2-BIT-A 0° L, 450 S, 600 S STM-24-04 450 S, 600 S
- L= Longitudinal, S= Shear There is no request for relief for any examination on any Residual Heat Removal Heat Exchanger at CNP.
W-CTSHEX is the West Containment Spray System Heat Exchanger and is constructed of Carbon Steel with Stainless Steel Cladding.
2-BIT-A is the Unit 2 Boron Injection Tank in Safety Injection portion of the Emergency Core Cooling System and is constructed of carbon steel with stainless steel cladding.
STM-24-04 is the Unit 2 #4 Steam Generator and is constructed of carbon steel with stainless steel cladding.
NRC Item 6 - RR ISIR-39 ASME Code, Section Xl, Examination Category C-B Pressure Nozzle Welds in Vessels Identify the system(s) and component(s) for the welds contained in Table 1 of RR ISIR-39.
I&M Response to NRC Item 6 The one component in RR ISIR-39 is STM-14-FWN, which is the Unit 1 #4 Steam Generator Feedwater Nozzle to Shell weld.
Enclosure 1 to AEP-NRC-2012-2 Page 7 NRC Item 7 - RR ISIR-40 ASME Code, Section Xl, Category C-C Integral Attachments for Vessels, Piping Pumps, and Valves Table I of RR ISIR-40 describes the examination performed as "UT" while the supporting documentation shows that dye penetrant (PT) examinations were performed. Clarify Table I of RR ISIR-40. Does Table I of RR ISIR-40 contain a typographical error or were UT examinations performed on the subject welds?
State the materials of construction for the welds and attachments.
Identify the system(s) and components for the subject welds in Table I of RR ISIR-40.
I&M Response to NRC Item 7 There was a typographical error in Section 3. RR ISIR-40 Section 3 should have identified that the relief was for limitations preventing 100% surface examination of the required area and not a volumetric examination. The remaining Sections of the relief correctly identify the surface method and the impracticality for the surface examination. RR ISIR-40 has been corrected to reflect this.
The materials for all welds and attachments are carbon steel. For all welds in Table 1 of RR ISIR-40, the system is Main Steam. The components for the welds are described in the "Weld Description" column of Table 1 of RR ISIR-40. The component for 1-MS-6-11S-PS is main steam piping. The component for MSIV-MRV-230-S2 is a support for a main steam isolation valve.
NRC Item 8 - RR ISIR-41 ASME Code, Section Xl, C-F-1 Pressure Retaining Welds in Austenitic Stainless Steel of High Alloy Piping Identify the system(s), and nominal pipe diameters or components for welds 1 -CTS-2-18F, 1-SI-2-42S, I-SI-24-06F, I -SI-30-08F, 1-SI-11A-01S, 1-SI-11-01S, I-S1-11-05F, I-SI-74-01F, 2-SI-42-OIS, and 2-SI-42-03F.
The diagram for weld 1-SI-24-06F appears to be incorrect or mislabeled. Where one would expect the diagram for 1-SI-24-06F (Pages 186 and 187 of the licensee's submittal dated April 8, 2011) there are two diagrams labeled 1-S1-152N with image dates of 12/30/1899 and 04/14/1997. (No relief is requested for I-S1-152N.) Clarify and provide a diagram or photograph identifying weld 1-SI-24-06F.
It appears that additional coverage could be obtained for welds 1-SI-11A-01S or 1-SI-11-01S by unbolting the pipe and examining them from the inner-diameter. Are there any plans to unbolt either of these fixtures in future inspection periods?
State the material of construction of the piping, valves, elbows, flange, and tees. Identify the dissimilar metal welds in Table I of RR ISIR-41, if any.
to AEP-NRC-2012-2 Page 8 I&M Response to NRC Item 8 The Requested Systems, Nominal Pipe Sizes, and materials are provided in the table below.
Component ID System Nominal Pipe Size Material (NPS) 1-CTS-2-18F Containment Spray 6.0 SS Type 304 1-SI-2-42S Safety Injection 12.0 SS Type 316 1-SI-24-06F Safety Injection 8.0 SS Type 316 1-SI-30-08F Safety Injection 10.0 SS Type 316 1 -SI-11A-01S Safety Injection 2.5 SS Type 304 1-SI-11-01S Safety Injection 2.5 SS Type 304 1-SI-11-05F Safety Injection 4.0 SS Type 304 1-SI-74-01F Safety Injection 4.0 SS Type 316 2-SI-42-01S Safety Injection 2.5 SS Type 304 2-SI-42-03F Safety Injection 4.0 SS Type 304 The image labeled 1-SI-152N was intended as an aid to location orientation for the pipe to tee weld (1-SI-24-06F). A new image is provided, in the Supporting Documentation section of RR ISIR-41, which clearly identifies the location of 1-SI-24-06F on the image. For reference, 1-SI-1 52N is the label for the check valve in the image.
There are no plans to disassemble any portion of the piping system to examine 1-SI-1i1A-01S or 1-SI-11-01S from the inner diameter.
There are no dissimilar metal welds contained in RR-ISIR-41.
NRC Item 9 - RR ISIR-42 ASME Code. Section Xl. Examination Cateqorv R-A. Items R1111.
R1.16, and R.120 Submit detailed and specific information to support the bases for limited volumetric coverage in ASME Code,Section XI, Examination Category R-A piping welds, and therefore, demonstrate impracticality.
As applicable, describe NDE equipment (UT scanning apparatus). Discuss whether alternative methods or advanced technologies could be employed to maximize ASME Code coverage.
Fully clarify, in a table, the wave modality and insonification angles used for all UT examinations to AEP-NRC-2012-2 Page 9 Confirm whether the examinations listed for all ASME Code, Section Xl, Examination Category R-A welds were conducted in accordance with the performance demonstration requirements of ASME Code,Section XI, Appendix VIII.
The NRC staff has had recent difficulties with risk-informed relief requests in that multiple licensees have misidentified the inspection categories for welds in several relief requests. The misidentification of the welds can result in delays in finishing the safety evaluation if it is not discovered in a timely fashion. Please review the inspection categories for these welds and confirm that all of the welds as shown in Table I of ISIR-42 are properly identified as per ASME Code Case N-716. [ASME Code Case N-716 has not been approved for use in RG-1.147, Revision 15. Licensees base their RI-ISI inspection sample size and examination methodology on Table I of ASME Code Case N-716.]
Discuss whether additional or alternative welds could have been examined to augment the reduced volumetric coverage resulting from the limited examinations of the subject welds.
Identify the system(s), and nominal pipe diameters or components for welds 2-SI-569-49S, 2-SI-569-53S, and 2-SI-569-54S.
State the material of construction of the piping, valves, elbows, flange, welds, and tees.
Identify the dissimilar metal welds in Table I of RR-42, if any.
Photographs were provided for welds 2-RC-22-24, 2-RC-23-12, and 2-RC-24-09; however, these photographs do not identify which welds in the images correspond to the welds in question. Please identify which welds in the photographs correspond to welds 2-RC-22-24, 2-RC-23-12, and 2-RC-24-09.
I&M Response to NRC Item 9 Each component has detailed and specific descriptions of each limitation in the supporting documentation. RR ISIR-42 requests relief from the requirement for 100% volumetric examination coverage. Twenty-one of the twenty-three components have only one side of the austenitic weld accessible, and therefore only half of the coverage can be credited, which demonstrates impracticality. Component IDs 2-SI-57-19 and 2-SI-57-22 were further limited by bevels adjacent to the weld toes. The remaining component IDs have interferences created by either a permanently installed structural pipe restraint (2-SI-56-10) or a bevel at the weld toe (1-RC-8-02S) which demonstrates impracticality. Each component has specific descriptions of each limitation in the column titled "Remarks" in Table 1 of ISIR-42. Additional detail is also provided in the Supporting Documentation section of RR ISIR-42 of Reference 1.
When these examinations were performed, PA techniques were not yet qualified under the PDI and were therefore not available for use. Additionally, PA cannot overcome certain limitations such as material (CASS), physical obstructions, or prohibitions against crediting more than 50%
of examination coverage when only one side of an austenitic weld is accessible. Radiography techniques have not been demonstrated as an equivalent volumetric technique to PDI qualified to AEP-NRC-2012-2 Page 10 examinations and would be a significant hardship on resources due to the required evacuation of work areas for extended periods of time.
The NDE equipment used was standard ultrasonic scopes, transducers, and wedges that were authorized for use by the PDI at the time of the examinations. The size, shape, and proximity of obstructions are described in the NDE datasheets for each component. At the time of the examinations, no advanced ultrasonic or radiographic techniques were qualified for use; therefore, no alternative examinations were explored.
All wave modes and insonification angles were previously identified in the component NDE Datasheet, which were provided in the Supporting Documentation section of RR ISIR-42 by Reference 1. The table below provides a summary of the wave modes and insonification angles for each component.
Component ID Insonification Angle(s) Wave Mode*
1-CS-96-60F 00 L, 45 0 S, 60°S 1-SI-29-19S 0°L, 45°S, 60°RL 1-SI-29-20S 0°L, 450 S, 60°RL 1-SI-29-23S 0°L, 450 S, 60°RL 1-SI-31-21S 0°L, 450 S, 60°RL 2-SI-57-19 0°L, 45 0 S, 600S, 60°RL 2-SI-57-21 0°L, 45 0 S, 600 S, 60°RL 2-SI-56-18 0°L, 45 0 S, 60 0S, 600 L 1-SI-548-45S 0°L, 3 0 °S, 450 S, 600 S, 1-RH-30-06F 45°S, 60 0 S, 60°RL 1-RC-8-02S 45S, 600 S 1-SI-29-26F 45 0 S, 60 0 S, 60°RL 1-SI-33-26F 450S, 60 0 S, 60°RL 2-RC-22-24 0°L, 45 0S, 600 L, 700S to AEP-NRC-2012-2 Page 11 Component ID Insonification Angle(s) Wave Mode*
2-RC-23-12 0°L, 45°S, 600 L, 70°S 2-RC-24-09 0°L, 45 0S, 600 L, 700S 2-SI-569-49S 450S 2-SI-569-53S 45 0 S 2-SI-569-54S 450S 2-SI-57-22 0°L, 450S, 600S, 60°RL 2-SI-56-10 0°L, 450S, 600S, 600L 2-SI-78-01 450S, 600S, 60-L 2-SI-56-22 0°L, 450S, 600S, 60°L
- L= Longitudinal, S= Shear and RL = Refracted Longitudinal As previously stated in Sections 2, 3, 4, and 6 of RR ISIR-42 by Reference 1, the examinations were performed using qualified Appendix VIII examinations (as modified by the PDI and 10 CFR 50.55a).
All of the welds in Table 1 of RR ISIR-42 have been verified to be in the correct inspection category of ASME Code Case N-716.
The weld selection process for CNP was accomplished during the development of the Risk-Informed Inservice Inspection (RI-ISI) program using an expert panel of operations, radiation protection, scaffold/insulation, system engineering, NDE, and ISI personnel. Aspects evaluated for weld selection included, but was not limited to, access, previous history, radiological exposure, industry operating experience, and system operation.
When confronted with a limitation on a weld, an evaluation is made to determine if a replacement weld can be substituted for the weld experiencing a limitation. There are many considerations that must be evaluated before a weld can be substituted, such as whether the substituted weld is subject to the same degradation mechanism, whether additional coverage can be achieved on the substitute weld, whether additional resources such as weld prep, insulation removal and scaffolding are required. Additionally, welds with similar or more limiting limitations are not substituted. Therefore, typically the weld originally selected is the best fit.
to AEP-NRC-2012-2 Page 12 The process of identifying additional welds for examination during a refueling outage to accommodate a potential increase in weld coverage employs the risk-informed approach and its limitations. Additionally, impact to personnel and equipment safety is also considered. Based on these considerations, no additional or alternative welds were examined.
The nominal pipe diameter for 2-SI-569-49S, 2-SI-569-53S, and 2-SI-569-54S is 1.5" and these welds are located in the Safety Injection system.
All materials in RR ISIR-42 are Stainless Steel Type 304 or 316. There are no dissimilar metal welds contained in RR ISIR-42.
The photographs provided for 2-RC-22-24, 2-RC-23-12, and 2-RC-24-09 were included for illustrative purposes only and not intended as the basis for the limitations. It was thought that a visual perspective would be helpful in understanding the configuration. Annotated drawings have been added to the Supporting Documentation section of RR ISIR-42 for 2-RC-22-24, 2-RC-23-12, and 2-RC-24-09 with the applicable weld locations identified.
Enclosure 2 to AEP-NRC-2012-2 REVISED INSERVICE INSPECTION RELIEF REQUESTS ISIR-33 THROUGH ISIR-42 to AEP-NRC-2012-2 Page 1 RELIEF REQUEST ISIR-33 EXAMINATION CATEGORY B-A PRESSURE RETAINING WELDS IN REACTOR VESSEL and EXAMINATION CATEGORY B-D FULL PENETRATION WELDS OF NOZZLES IN VESSELS - INSPECTION PROGRAM B (Reactor Vessel only) to AEP-NRC-2012-2 Page 2 RELIEF REQUEST ISIR-33 Relief Request In Accordance with 10 CFR 50.55a(g)(5)(iii)
Inservice Inspection Impracticality
- 1. ASME Code Components Affected ASME Code Class: Code Class 1 Examination Category: B-A, Pressure Retaining Welds in Reactor Vessel B-D, Full Penetration Welds of Nozzles in Vessels - Inspection Program B (Reactor Vessel only)
Item Numbers: B 1.11, Shell Welds - Circumferential B1.12, Shell Welds - Longitudinal B1 .21, Head Welds - Circumferential B1.22, Head Welds - Meridional B3.90, Reactor Vessel - Nozzle to Vessel Welds Component Identification: Listed in Table 1
- 2. Applicable Code Addition and Addenda ASME Section Xl, 1989 Edition, No addenda
3. Applicable Code Requirement
ASME Section XI, 1989 Edition, Examination Category B-A requires volumetric examination of 100 percent of the weld volume as defined in ASME Section XI Table IWB-2500-1 and shown in Figures IWB-2500-1, IWB-2500-2 and IWB- 2500-3. The alternative requirements of ASME Section Xl, Code Case N-460, approved for use in Regulatory Guide 1 .147 Rev. 15, allows credit for essentially 100 percent coverage of the weld provided greater than 90 percent of the required volume has been examined.
- 4. Impracticality of Compliance Pursuant to 10 CFR 50.55a(g)(5)(iii), relief is requested from the essentially 100 percent volumetric examination coverage requirement for the subject Welds. Due to the design of the reactor vessel, geometric configuration and permanent obstructions limit the volumetric examination coverage of the subject welds.
During the second 10-year reactor pressure vessel examination, the best available technology was utilized in performing the automated ultrasonic examination. The examinations were performed with equipment, procedures and personnel qualified in accordance with the requirements of ASME Section Xl, Appendix VIII, 1995 Edition thru 1996 Addenda as modified by the Performance Demonstration Initiative (PDI) program.
to AEP-NRC-2012-2 Page 3 Several interferences and vessel geometries prevent full volumetric examination coverage, including the 58 permanent incore instrument nozzles penetrating the bottom head and six core support lugs permanently attached to the vessel interior limiting the access to the lower head welds. The close proximity of the inlet nozzle and outlet nozzle boss limits the ultrasonic scanning of the upper shell longitudinal seam welds. The flange to vessel configuration, specimen slots, and keyways also hinder access. These noted obstructions prevent achieving the essentially.100 percent volumetric examination coverage required by code. Also, Nozzle to Vessel geometry, vessel saddle effect, and adjacent outlet nozzle protrusion limited access for achieving 100 percent volumetric examination coverage for the Nozzle to Vessel welds.
The limitations and the actual examination coverage attained for each weld for which relief is requested are noted in the Table 1.
- 5. Burden Caused by Compliance To increase examination coverage on the subject welds requires a significant design modification or replacement of components with a different design to eliminate the noted obstructions. This is impractical due to the cost, additional radiation exposure and impact to plant equipment.
- 6. Proposed Alternative and Basis for Use The subject welds received a volumetric examination on the accessible portions of the subject welds to the maximum extent practical given the limitations caused by the geometric configuration and permanent obstructions. Additionally, a visual examination (VT-2) is performed at the end of each refueling outage during the system leakage tests as required by Section Xl, IWB-2500-1, Category B-P.
Based upon the examination volumes that were obtained with acceptable results along with the visual (VT-2) examination performed each refueling outage, it is reasonable to conclude that service induced degradation would be detected. Therefore, these proposed alternatives provide an acceptable level of quality and safety by providing reasonable assurance of structural integrity of the subject welds.
- 7. Period for Which Relief is Requested The relief is requested for the Third 10-year inspection interval for D.C. Cook Units 1 and 2, which began on July 1, 1996 and ended April 9, 2010 at the conclusion of the Unit 1 Cycle 23 Refueling Outage. Significant long-term outages (greater than six months) occurred multiple times during the interval and the interval was extended as allowed by IWA-2430(e) and by IWA-2430(d) to accommodate interva.l planning and scheduling.
to AEP-NRC-2012-2 Page 4 Table 1 to Relief Request ISIR-33 Ultrasonic CNP Item Examination Cvrg eak Weld Description Number Coverage Remarks Unit Component ID. Attained (%)/
PDI (Y/N)
The completed examination was limited to 84.4%
coverage due to the configuration. The limitations 1 1-RPV-A Shell to Flange B1.30 84.44NY are due to flange configuration, specimen slots, and keyways at 0, 90, 180, and 270 degrees. No recordable indications detected.
The completed examination was limited to 82.60%
Lower Shell to Bottom coverage due to the configuration. The limitations Head are due to six core support lugs. No recordable indications detected.
The completed examination was limited to 38.4%
1 1-RPV-E Dollar Plate B1.21 38.4/Y coverage due to the configuration. The limitation is due to the penetrations. bottom mounted No recordable indications instrument detected.
Lower Shell The completed examination was limited to 78.29%
1 1-RPV-VC1 Longitudinal at 60 B1.12 78.29/Y coverage due to the configuration. The limitation Degrees is due to the core support lug. No recordable indications detected.
Lower Shell The completed examination was limited to 78.29%
1 1-RPV-VC2 Longitudinal at 180 B1.12 78.29/Y coverage due to the configuration. The limitation Degrees is due to the core support lug. No recordable indications detected.
Lower Shell The completed examination was limited to 78.29%
1 1-RPV-VC3 Longitudinal at 300 B1.12 78.29/Y coverage due to the configuration. The limitation Degrees is due to the core support lug. No recordable I I I indications detected.
to AEP-NRC-2012-2 Page 5 Ultrasonic Unit Component ID Weld Description Examination Number Coverage Remarks Attained (%)/
PDI (Y/N)
Lower Head The completed examination was limited to 79.0%
1 1-LHM-01 Meridional at 30 B1.22 79.0/ coverage due to the configuration. The limitation Degrees is due to bottom mounted instrumentation penetrations. No recordable indications detected.
Lower Head The completed examination was limited to 73.26%
1 1-LHM-02 Meridional at 90 B1.22 73.26/Y coverage due to the configuration. The limitation Degrees is due to bottom mounted instrumentation penetrations. No recordable indications detected.
Lower Head The completed examination was limited to 88.1%
1 1-LHM-05 Meridional at 270 B1.22 88.11Y coverage due to the configuration. The limitation Degrees is due to bottom mounted instrumentation penetrations. No recordable indications detected.
Lower Head The completed examination was limited to 74.5%
1 1-LHM-06 Meridional at 330 B1.22 74.5/Y coverage due to the configuration. The limitation Degrees is due to bottom mounted instrumentation penetrations. No recordable indications detected.
The completed examination was limited to 71.08%
coverage due to the configuration. The limitation 1-N3B Outlet Nozzle to Shell B3.90 71.08N is at 22 Degrees anddueadjacent to nozzleoutlet geometry, nozzlevessel saddle effect, protrusion. Two subsurface indications were detected and evaluated as acceptable to IWB-3512-1.
The completed examination was limited to 71.08%
coverage due to the configuration. The limitation 1-N4B Outlet Nozzle to Shell B3.90 71.08N is due to nozzle geometry, vessel saddle effect, at 158 Degrees and adjacent outlet nozzle protrusion. One subsurface indication was detected and evaluated as acceptable to IWB-3512-1.
to AEP-NRC-2012-2 Page 6 Ultrasonic Examination CNP Component ID Weld Description Item Coverage Remarks Unit Number Attained
(%)I PDI (Y/N)
The completed examination was limited to 71.08%
coverage due to the configuration. The limitation 1-N1B Outlet Nozzle to Shell at B3.90 71.08NY is due to nozzle geometry, vessel saddle effect 202 Degrees and adjacent outlet nozzle protrusion. Six subsurface indications were detected and evaluated as acceptable to IWB-3512-1.
The completed examination was limited to 71.08%
coverage due to the configuration. The limitation 1-N2B Outlet Nozzle to Shell at B3.90 71.08/Y is due to nozzle geometry, vessel saddle effect 338 Degrees and adjacent outlet nozzle protrusion. Eight subsurface indications were detected and evaluated as acceptable to IWB-3512-1.
to AEP-NRC-2012-2 Page 7 RELIEF REQUEST ISIR-33 EXAMINATION CATEGORY B-A PRESSURE RETAINING WELDS IN REACTOR VESSEL And EXAMINATION CATEGORY B-D FULL PENETRATION WELDS OF NOZZLES IN VESSELS - INSPECTION PROGRAM B (Reactor Vessel only)
SUPPORTING DOCUMENTATION IS PROVIDED BY I&M LETTER DATED APRIL 8, 2011 ADAMS ACCESSION NO. ML11110A042 to AEP-NRC-2012-2 Page 8 RELIEF REQUEST ISIR-34 EXAMINATION CATEGORY B-B PRESSURE RETAINING WELDS IN VESSELS OTHER THAN REACTOR VESSELS to AEP-NRC-2012-2 Page 9 RELIEF REQUEST ISIR-34 Relief Request In Accordance with 10 CFR 50.55a(g)(5)(iii)
Inservice Inspection Impracticality
- 1. ASME Code Components Affected ASME Code Class: Code Class 1 Examination Category: B-B, Pressure Retaining Welds in Vessels Other Than Reactor Vessels Item Numbers: B2.40, Steam Generators (Primary Side) - Tubesheet to Head Component Identification: Listed in Table 1
2. Applicable Code Edition and Addenda
ASME Section Xl, 1989 Edition, No addenda
3. Applicable Code Requirement
ASME Section XI, 1989 Edition, Examination Category B-B requires volumetric examination of 100 percent of the weld volume as defined in Table IWB-2500-1 and shown in Figures IWB-2500-1 and IWB-2500-6. The alternative requirements of ASME Section XI, Code Case N-460, approved for use in Regulatory Guide 1.147, Revision 15, allows credit for essentially 100 percent coverage of the welds provided greater than 90 percent of the required volume has been examined.
- 4. Impracticality of Compliance Pursuant to 10 CFR 50.55a(g)(5)(iii), relief is requested from the essentially 100 percent volumetric examination coverage requirement for the subject welds due to the geometric configuration and permanent obstructions which limit the volumetric examination coverage of the subject welds.
The Steam Generator Tubesheet to Head Weld (2-24-01) was limited to 72% coverage due to the configuration. Examination coverage was limited due to the proximity of welded pads, nozzles, adjacent piping, hand-hole openings, permanent support brackets, and permanent electrical conduits.
These noted obstructions prevent achieving the essentially 100 percent volume examination coverage required by code.
The limitations and the actual examination coverage attained for each weld for which relief is requested are noted in Table 1.
to AEP-NRC-2012-2 Page 10
- 5. Burden Caused by Compliance To increase the examination coverage for STM-24-01 requires removal and reinstallation of insulation support ring mounting pads by cutting the mounting pad welds and then reinstalling the mounting pads by welding following completion of the examination. Additionally, to increase examination coverage on the subject weld would require a significant design modification or replacement of components with a different design to eliminate the noted obstructions. This is impractical due to the cost, additional radiation exposure, and impact to plant equipment.
- 6. Proposed Alternative and Basis for Use The subject welds received a volumetric examination on the accessible portions of the subject welds to the maximum extent practical given the limitations caused by the geometric configuration and permanent obstructions. Additionally, a visual examination (VT-2) is performed at the end of each refueling outage during the system leakage tests as required by Section Xl, IWB-2500-1, Category B-P.
Based upon the examination volumes that were obtained with acceptable results, along with the visual (VT-2) examination performed each refueling outage, it is reasonable to conclude that service induced degradation would be detected. Therefore, these proposed alternatives provide an acceptable level of quality and safety by providing reasonable assurance of structural integrity of the subject welds.
- 7. Period for Which Relief is Requested The relief is requested for the Third 10-year inspection interval for Donald C. Cook Nuclear Plant Units 1 and 2, which began on July 1, 1996, and ended April 9, 2010, at the conclusion of the Unit 1 Cycle 23 Refueling Outage. Significant long-term outages (greater than six months) occurred multiple times during the interval and the interval was extended as allowed by IWA-2430(e) and by IWA-2430(d) to accommodate interval planning and scheduling.
to AEP-NRC-2012-2 Page 11 Table 1 to Relief Request ISIR-34 Ultrasonic Examination CNP Component ID Weld Description Item Coverage Unit Number Attained
(%)I PDI (Y/N)
The completed examination was limited to 72%
coverage due to the configuration. Examination o72.0/N (per coverage was limited due to the proximity of welded STM- Shell 2 Tubesheet to 1Lower B2.40 7 4per pads, nozzles, adjacent piping, hand-hole openings,Section V) permanent support brackets, and permanent electrical conduits. One subsurface indication was detected and evaluated as acceptable to IWB-3512-1.
to AEP-NRC-2012-2 Page 12 RELIEF REQUEST ISIR-34 EXAMINATION CATEGORY B-B PRESSURE RETAINING WELDS IN VESSELS OTHER THAN REACTOR VESSELS SUPPORTING DOCUMENTATION IS PROVIDED BY I&M LETTER DATED APRIL 8, 2011 ADAMS ACCESSION NO. ML11111OA042 to AEP-NRC-2012-2 Page 13 RELIEF REQUEST ISIR-35 EXAMINATION CATEGORY B-D FULL PENETRATION WELDS OF NOZZLES IN VESSELS - INSPECTION PROGRAM B to AEP-NRC-2012-2 Page 14 RELIEF REQUEST ISIR-35 Relief Request In Accordance with 10 CFR 50.55a(g)(5)(iii)
Inservice Inspection Impracticality
- 1. ASME Code Components Affected ASME Code Class: Code Class 1 Examination Category: B-D, Full Penetration Welds of Nozzles in Vessels - Inspection Program B Item Numbers: B3. 110, Pressurizer, Nozzle to Vessel Welds B3.140, Steam Generators (Primary Side) - Nozzle Inside Radius Section (IRS)
Component Identification: Listed in Table 1
2. Applicable Code Edition and Addenda
ASME Section Xl, 1989 Edition, No addenda
3. Applicable Code Requirement
ASME Section Xl, 1989 Edition, Examination Category B-D requires volumetric examination of 100 percent of the weld volume as defined in Table IWB-2500-1 and shown in Figures IWB-2500-7(a) thru (d) as applicable. The alternative requirements of ASME Section Xl, Code Case N-460, approved for use in Regulatory Guide 1.147, Revision 15, allows credit for essentially 100 percent coverage of the welds provided greater than 90 percent of the required volume has been examined.
- 4. Impracticality of Compliance Pursuant to 10 CFR 50.55a(g)(5)(iii), relief is requested from the essentially 100 percent volumetric examination coverage requirement for the subject welds due to the geometric configuration and permanent obstructions which limit the volumetric examination coverage of the subject welds.
The Steam Generator Inner Radius examinations (STM-12-1-IRS, STM-12-O-IRS, STM-14-1-IRS and STM-14-0-IRS) were limited to 34.9%, 36.8%, 40.9% and 25% coverage, respectively. Due to the component geometry, no coverage of the inner radius region can be effectively obtained by scanning from the shell side. No contact could be maintained in the blend radius area.
Additionally, the pressurizer Nozzle to Vessel welds (2-RC-26 and 2-RC-27) were each limited to 75% coverage. Examination limitations were due to the contour of the weld on the nozzle side, where 50% coverage was achieved for both the 45 and 60 degree axial scans.
to AEP-NRC-2012-2 Page 15 These noted obstructions prevent achieving the essentially 100 percent volumetric examination coverage required by code.
The limitations and the actual examination coverage attained for each weld for which relief is requested are noted in Table 1.
- 5. Burden Caused by Compliance To increase examination coverage on the subject weld would require a significant design modification or replacement of components with a different design to eliminate the noted obstructions. This is impractical due to the cost, additional radiation exposure, and impact to plant equipment.
- 6. Proposed Alternative and Basis for Use The subject welds received a volumetric examination on the accessible portions of the subject welds to the maximum extent practical. Additionally, welds 2-RC-26 and 2-RC-27 received a Surface Examination. Further, a visual examination (VT-2) is performed at the end of each refueling outage during the system leakage tests as required by Section Xl, IWB-2500-1, Category B-P.
Based upon the examination volumes that were obtained with acceptable results, along with the visual (VT-2) examination performed each refueling outage, it is reasonable to conclude that service induced degradation would be detected. Therefore, these proposed alternatives provide an acceptable level of quality and safety by providing reasonable assurance of structural integrity of the subject welds.
- 7. Period for Which Relief is Requested The relief is requested for the Third 10-year inspection interval for Donald C. Cook Nuclear Plant Units 1 and 2, which began on July 1, 1996, and ended April 9, 2010, at the conclusion of the Unit 1 Cycle 23 Refueling Outage. Significant long-term outages (greater than six months) occurred multiple times during the interval and the interval was extended as allowed by IWA-2430(e) and by IWA-2430(d) to accommodate interval planning and scheduling.
to AEP-NRC-2012-2 Page 16 Table 1 to Relief Request ISIR-35 Ultrasonic Examination CNP Unit Component ID Weld Description Item Number Coverage Remarks Attained (%)/
PDI (Y/N)
The completed examination was limited to 40.9%
coverage due to the configuration. Due to the Inlet Nozzle Inside 40.9/N-(per component geometry, no coverage of the inner radius STM-14-1-IRS Radius Section B3.140 Article 4 of region can be effectively obtained by scanning from Section V) the shell side. No contact could be maintained in the blend radius area. No recordable indications detected.
The completed examination was limited to 25%
coverage due to the configuration. Due to the 25.0/N (per component geometry, no coverage of the inner radius IRSTRadOut IRS Radius Secions Section B3.140 Article 4 of region can be effectively obtained by scanning from Section V) the shell side. No contact could be maintained in the blend radius area. No recordable indications detected.
The completed examination was limited to 34.9%
coverage due to the configuration. Due to the 34.9/N (per component geometry, no coverage of the inner radius STM-12-1-IRS Radius Section B3.140 Article 4 of region can be effectively obtained by scanning from Section V) the shell side. No contact could be maintained in the blend radius area. No recordable indications detected.
to AEP-NRC-2012-2 Page 17 Ultrasonic CNP ompoent tem Examination CNP Component Weld Description Itemb Coverage Remarks Unit ID Number Cvrg Attained (%)/
PDI (Y/N)
The completed examination was limited to 36.8%
coverage due to the configuration. Due to the 36.8/N (per component geometry, no coverage of the inner radius 1 STMRadiO-IRS ue N Section Radius ecions B3.140 Article 4 of region can be effectively obtained by scanning from Section V) the shell side. No contact could be maintained in the blend radius area. No recordable indications detected.
The completed examination was limited to 75%
coverage due to the configuration. Exam limitations 2 2-RC-26 Upper Head to Relief B3.110 75.0/ (per Article were due to the contour of the weld on the nozzle Nozzle 4 of Section V) side, where 50% coverage was achieved for both the 45 and 60 degree axial scans. No recordable indications detected.
The completed examination was limited to 75%
coverage due to the configuration. Exam limitations 2 2-RC-27 Upper Head to Relief B3.1 10 75.0/ (per Article were due to the contour of the weld on the nozzle Nozzle 4 of Section V) side, where 50% coverage was achieved for both the 45 and 60 degree axial scans. No recordable indications detected.
to AEP-NRC-2012-2 Page 18 RELIEF REQUEST ISIR-35 EXAMINATION CATEGORY B-D FULL PENETRATION WELDS OF NOZZLES IN VESSELS - INSPECTION PROGRAM B SUPPORTING DOCUMENTATION IS PROVIDED BY I&M LETTER DATED APRIL 8, 2011 ADAMS ACCESSION NO. ML11110A042 to AEP-NRC-2012-2 Page 19 RELIEF REQUEST ISIR-36 EXAMINATION CATEGORY B-F PRESSURE RETAINING DISSIMILAR METAL WELDS to AEP-NRC-2012-2 Page 20 RELIEF REQUEST ISIR-36 Relief Request In Accordance with 10 CFR 50.55a(g)(5)(iii)
Inservice Inspection Impracticality
- 1. ASME Code Components Affected ASME Code Class: Code Class 1 Examination Category: B-F, Pressure Retaining Dissimilar Metal Welds Item Numbers: B5.70, Steam Generator, Nozzle to Safe End Butt Welds Component Identification: Listed in Table 1
2. Applicable Code Edition and Addenda
ASME Section XI, 1989 Edition, No addenda
3. Applicable Code Requirement
ASME Section Xl, 1989 Edition, Examination Category B-F requires volumetric examination of 100 percent of the weld volume as defined in Table IWB-2500-1 and shown in Figure IWB-2500-8. The alternative requirements of ASME Section XI, Code Case N-460, approved for use in Regulatory Guide 1.147, Revision 15, allows credit for essentially 100 percent coverage of the welds provided greater than 90 percent of the required volume has been examined.
- 4. Impracticality of Compliance Pursuant to 10 CFR 50.55a(g)(5)(iii), relief is requested from the essentially 100 percent volumetric examination coverage requirement for the subject welds due to the geometric configuration and permanent obstructions which limit the volumetric examination coverage of the subject welds.
The Steam Generator Nozzle to Safe End examinations (STM-12-02R, STM-12-03R, STM-14-02R, and STM-14-03R) were limited to 25.72%, 23.92%, 25.72%, and 23.9%
coverage respectively due to the component geometry. Coverage was limited due to tapers, weld contours, and depressions on some of the nozzles.
The Safe End to Elbow examinations (STM-22-02, STM-22-03, STM-23-02, and STM-23-03) were limited to 19.5%, 19.5%, 19.5% and 19.5% coverage respectively due to limitations encountered with the contour of the weld along with depressions on the nozzle side of the weld and the CASS Elbow material.
These noted obstructions prevent achieving the essentially 100 percent volume examination coverage required by code.
to AEP-NRC-2012-2 Page 21 The limitations and the actual examination coverage attained for each weld for which relief is requested are noted in Table 1.
- 5. Burden Caused by Compliance Class 1 piping and components are often designed with welded joints such as nozzle-to-pipe, pipe-to valve, and pipe-to-pump which can physically obstruct a large portion of the required examination volume. For the welds listed in Table 1, the examinations were performed after the 10 CFR 50.55a mandatory implementation date (November 22, 2002) for Appendix VIII of Section Xl. The provided code coverage percentages reflect what is currently allowed by qualified Appendix VIII techniques. Appendix VIII qualified (PDI) procedures have demonstrated that sound beams may potentially be attenuated and distorted when required to pass through austenitic weld metal. However, the PDI qualified methods employ the best available technology for maximizing examination coverage of these types of welds. For the components listed in this relief request, examination was extended to the far side of the weld to the extent permitted by geometry as qualified through PDI. Indiana Michigan Power Company (I&M) has used the best available techniques to examine the subject piping welds.
To improve upon these examination coverage percentages, modification and/or replacement of the component would be required. No alternative testing is proposed at this time. I&M has examined the subject welds to the extent practical and will continue to perform pressure testing on the subject welds as required by the Code. I&M also performed surface examinations of 100% of the required area without limitations.
Additionally, for the welds consisting of CASS Elbow material (STM-22-02, STM-22-03, STM-23-02 and STM-23-03), there are currently no Appendix VIII PDI qualified procedures to inspect Cast Austenitic Stainless Steel (CASS) materials. The Steam Generator Inlet and Outlet nozzle configuration includes an austenitic stainless steel safe-end welded to a cast austenitic stainless steel elbow. The Appendix VIII procedure qualified for the examination of austenitic stainless steel welds from the Outside Diameter surface was used to perform a best effort examination of the CASS elbow material.
To increase examination coverage on the subject weld would require a significant design modification or replacement of components with a different design or material to eliminate the noted obstructions or material limitations. This is impractical due to the cost, additional radiation exposure, and impact to plant equipment.
- 6. Proposed Alternative and Basis for Use The subject welds received a volumetric examination on the accessible portions of the subject welds to the maximum extent practical. Each weld also received a surface examination without limitations. Additionally, a visual examination (VT-2) is performed at the end of each refueling outage during the system leakage tests as required by Section Xl, IWB-2500-1, Category B-P.
Based upon the examination volumes that were obtained with acceptable results along with the completed surface examination and the visual (VT-2) examination performed each refueling outage, it is reasonable to conclude that service induced degradation would be to AEP-NRC-2012-2 Page 22 detected. Therefore, these proposed alternatives provide an acceptable level of quality and safety by providing reasonable assurance of structural integrity of the subject welds.
- 7. Period for Which Relief is Requested The relief is requested for the Third 10-year inspection interval for Donald C. Cook Nuclear Plant Units 1 and 2, which began on July 1, 1996, and ended April 9, 2010, at the conclusion of the Unit 1 Cycle 23 Refueling Outage. Significant long-term outages (greater than six months) occurred multiple times during the interval and the interval was extended as allowed by IWA-2430(e) and by IWA-2430(d) to accommodate interval planning and scheduling.
to AEP-NRC-2012-2 Page 23 Table 1 to Relief Request ISIR-36 Ultrasonic CNP Component Weld Item Examination Coverage Remarks Unit ID Description Number Attained (%)/
PDI (Y/N)
The completed examination was limited to STMI Safe End to Inlet 25.72% coverage due to the configuration. The 1 02R Nozzle B5.70 25.72NY limited coverage of this weld is due to the configuration of the taper transition of the safe end. No recordable indications detected.
The completed examination was limited to STMI Safe End to Inlet 23.92% coverage due to the configuration. The 1 03R Nozzle B5.70 23.92/Y limited coverage of this weld is due to the configuration of the taper transition of the safe end. No recordable indications detected.
The completed examination was limited to STM Safe End to Inlet 25.72% coverage due to the configuration. The 1 02R Nozzle B5.70 25.72/Y limited coverage of this weld is due to the configuration of the taper transition of the safe end. No recordable indications detected.
The completed examination was limited to 23.9%
STM Safe End to Inlet coverage due to the configuration. The limited 1 03R Nozzle B5.70 23.9/Y coverage of this weld is due to the configuration of the taper transition of the safe end. No recordable indications detected.
The completed examination was limited to 19.5%
coverage due to the configuration. Limitations Elbow to Inlet were encountered due the contour of the weld Nozzle along with depressions on the nozzle side of the weld and the CASS Elbow material. No relevant indications detected.
to AEP-NRC-2012-2 Page 24 Ultrasonic CNP Component WItem Examination Unit ID Weld Description Number Coverage Attained (M)Y PDI (Y/N)
The completed examination was limited to 19.5%
coverage due to the configuration. Limitations 19.5/Y were wr encountered nonee due u the h contour otu offtewl the weld 2 STM-22-03 Elbow to Inlet Nozzle B5.70 along with depressions on the nozzle side of the weld and the CASS Elbow material. No relevant indications detected.
The completed examination was limited to 19.5%
coverage due to the configuration. Limitations 19.5/Y were wr encountered nonee due u the h contour otu offtewl the weld 2 STM-23-02 Elbow to Inlet Nozzle B5.70 along with depressions on the nozzle side of the weld and the CASS Elbow material. No relevant indications detected.
The completed examination was limited to 19.5%
coverage due to the configuration. Limitations B5.70 were encountered due the contour offtewl 19.5N/eeecutrddethYotu the weld 2 STM-23-03 Outlet Nozzle to Elbow along with depressions on the nozzle side of the weld and the CASS Elbow material. No relevant indications detected.
to AEP-NRC-2012-2 Page 25 RELIEF REQUEST ISIR-36 EXAMINATION CATEGORY B-F PRESSURE RETAINING DISSIMILAR METAL WELDS SUPPORTING DOCUMENTATION IS PROVIDED BY I&M LETTER DATED APRIL 8, 2011 ADAMS ACCESSION NO. ML1111OA042 to AEP-NRC-2012-2 Page 26 RELIEF REQUEST ISIR-37 EXAMINATION CATEGORY B-J PRESSURE RETAINING WELDS IN PIPING to AEP-NRC-2012-2 Page 27 RELIEF REQUEST ISIR-37 Relief Request In Accordance with 10 CFR 50.55a(g)(5)(iii)
Inservice Inspection Impracticality
- 1. ASME Code Components Affected ASME Code Class: Code Class 1 Examination Category: B-J, Pressure Retaining Welds in Piping Item Numbers: B9.1 1, NPS 4 and Larger, Circumferential Welds B9.31, Branch Pipe Connection Welds, NPS 4 or Larger Component Identification: Listed in Table 1
2. Applicable Code Edition and Addenda
ASME Section XI, 1989 Edition, No addenda
3. Applicable Code Requirement
ASME Section Xl, 1989 Edition, Examination Category B-J requires volumetric examination of 100 percent of the weld volume as defined in Table IWB-2500-1 and shown in Figures IWB-2500-8, or IWB-2500-9, -10 or -11. The alternative requirements of ASME Section Xl, Code Case N-460, approved for use in Regulatory Guide 1.147, Revision 15, allows credit for essentially 100 percent coverage of the welds provided greater than 90 percent of the required volume has been examined.
- 4. Impracticality of Compliance Pursuant to 10 CFR 50.55a(g)(5)(iii), relief is requested from the essentially 100 percent volumetric examination coverage requirement for the subject welds due to the geometric configuration and permanent obstructions which limit the volumetric examination coverage of the subject welds.
Due to the component geometry coverage was limited due to tapers, bevels, weld contours, and joint configurations.
These noted obstructions prevent achieving the essentially 100 percent volume examination coverage required by code.
The limitations and the actual examination coverage attained for each weld for which relief is requested are noted in Table 1.
to AEP-NRC-2012-2 Page 28
- 5. Burden Caused by Compliance During ultrasonic examination of the piping welds listed in Table 1 of this relief request, 100 percent coverage of the required examination volume could not be obtained. Class 1 piping and components are often designed with welded joints such as nozzle-to-pipe, pipe-to-valve, and pipe-to-pump which can physically obstruct a large portion of the required examination volume. For the welds listed in Table 1, the examinations were performed using Appendix VIII of Section Xl as modified by the PDI program. The provided code coverage percentages reflect what is allowed by qualified Appendix VIII techniques. Appendix VIII qualified PDI procedures have demonstrated that sound beams may potentially be attenuated and distorted when required to pass through austenitic weld metal. However, the PDI qualified methods employ the best available technology for maximizing examination coverage of these types of welds. For all the components listed in this relief request, examination was extended to the far side of the weld to the extent permitted by geometry, but this portion of the examination is not included in the reported coverage for welds examined under PDI and Appendix VIII rules. Indiana Michigan Power Company (I&M) has used the best available techniques to examine the subject piping welds. To improve upon these examination coverage percentages, modification and/or replacement of the component would be required.
No alternative testing is proposed at this time. I&M has examined the subject welds to the extent practical and will continue to perform pressure testing on the subject welds as required by the Code.
To increase examination coverage on the subject weld would require a significant design modification or replacement of components with a different design or material to eliminate the noted obstructions or material limitations. This is impractical due to the cost, additional radiation exposure and impact to plant equipment.
- 6. Proposed Alternative and Basis for Use The subject welds received a volumetric examination on the accessible portions of the subject welds to the maximum extent practical. Each weld also received a surface examination without limitations. Additionally, a visual examination (VT-2) is performed at the end of each refueling outage during the system leakage tests as required by Section Xl, IWB-2500-1, Category B-P.
Based upon the examination volumes that were obtained with acceptable results along with the completed surface examination and the visual (VT-2) examination performed each refueling outage, it is reasonable to conclude that service induced degradation would be detected if present. Therefore, these proposed alternatives provide an acceptable level of quality and safety by providing reasonable assurance of structural integrity of the subject welds.
to AEP-NRC-2012-2 Page 29
- 7. Period for Which Relief is Requested The relief is requested for the Third 10-year inspection interval for Donald C. Cook Nuclear Plant Units 1 and 2, which began on July 1, 1996, and ended April 9, 2010, at the conclusion of the Unit 1 Cycle 23 Refueling Outage. Significant long-term outages (greater than six months) occurred multiple times during the interval and the interval was extended as allowed by IWA-2430(e) and by IWA-2430(d) to accommodate interval planning and scheduling.
to AEP-NRC-2012-2 Page 30 Table 1 to Relief Request ISIR-37 Ultrasonic CNP Component Weld Item Examination Coverage Remarks Unit ID Description Number Attained (%)/
PDI (Y/N)
The completed examination was limited to 50%
1-RH coverage due to the configuration. The configuration 1 05F Pipe to Pipe B9.11 50.0/Y prevents examination on the penetration side due to the bevel and the contour of the ID and OD. No relevant indications detected.
The completed examination was limited to 50%
coverage due to the configuration. The coverage 1 1-SI-22-18F Pipe to B9.11 50.0/Y limitation was due to the OD bevel configuration on the Valve valve side of the weld. No relevant indications detected.
The completed examination was limited to 50%
coverage due to the configuration. The coverage 1 1-SI-23-17F Pipe to B9.11 50.0/Y limitation was due to the OD bevel configuration on the Valve valve side of the weld. No relevant indications detected.
The completed examination was limited to 50%
Branch to coverage due to the configuration. The exam limitation 1 1-RC-5-01F Pipe B9.11 50.0/Y was due to the proximity of the branch connection to the branch side weld. No relevant indications detected.
The completed examination was limited to 50%
coverage due to the configuration. The configuration 1 1-SI-33-23S Tee to Pipe B9.11 50.0/Y prevents examination on the tee side due to the sharp bevel adjacent to the tee side weld toe. No relevant indications detected.
to AEP-NRC-2012-2 Page 31 Ultrasonic CNP Component Weld Item Examination Coverage Remarks Unit ID Description Number Attained (%)/
PDI (Y/N)
The completed examination was limited to 65%
2 2-RC-22-01 Safe End to B9.11 65.0Y coverage due to the configuration. The configuration Elbow prevents examination due to the geometry of the safe end. No relevant indications detected.
The completed examination was limited to 66.7%
coverage due to the configuration. The configuration 2 2-RC-28-23 Tee to Pipe B9.11 66.7/Y prevents examination on the tee side due to the sharp bevel adjacent to the tee side weld toe. No relevant indications detected.
The completed examination was limited to 50%
coverage due to the configuration. The configuration 2 2-SI-56-19 Tee to Pipe B9.11 50.O0Y prevents examination on the tee side due to the sharp bevel adjacent to the tee side weld toe. No relevant indications detected.
The completed examination was limited to 50%
Branch to coverage due to the configuration. The configuration 2 2-RH-33-01 Pipe B9.11 50.O/Y prevents examination on the tee side due to the sharp bevel adjacent to the tee side weld toe. No relevant indications detected.
The completed examination was limited to 34%
coverage due to the configuration. Limitations were based on the joint configuration. No axial scans were 2-RC Branch to performed on the downstream side of the weld along 2 08N Brnc B9.31 34.O0Y with no circumferential scans on the branch connection 08N Pipe weld due to the contour of the weld. In addition, circumferential scans could only be performed on the branch connection base material. No relevant indications detected.
to AEP-NRC-2012-2 Page 32 RELIEF REQUEST ISIR-37 EXAMINATION CATEGORY B-J PRESSURE RETAINING WELDS IN PIPING SUPPORTING DOCUMENTATION IS PROVIDED BY I&M LETTER DATED APRIL 8, 2011 ADAMS ACCESSION NO. ML11110A042 to AEP-NRC-2012-2 Page 33 RELIEF REQUEST ISIR-38 EXAMINATION CATEGORY C-A PRESSURE RETAINING WELDS IN PRESSURE VESSELS to AEP-NRC-2012-2 Page 34 RELIEF REQUEST ISIR-38 Relief Requested In Accordance with 10 CFR 50.55a(g)(5)(iii) -
Inservice Inspection Impracticality
- 1. ASME Code Components Affected ASME Code Class: Code Class 2 Examination Category: C-A, Pressure Retaining Welds in Pressure Vessels Item Numbers: C1.10, Shell Circumferential Welds C1.20, Head Circumferential Welds C1.30, Tubesheet to Shell Weld Component Identification: Listed in Table 1
2. Applicable Code Edition and Addenda
ASME Section Xl, 1989 Edition, No addenda
3. Applicable Code Requirement
ASME Section Xl, 1989 Edition, Examination Category C-A requires volumetric examination of 100 percent of the weld volume as defined in Table IWC-2500-1 and shown in Figures IWC-2500-1 or IWC-2500-2 as applicable. The alternative requirements of ASME Section Xl, Code Case N-460, approved for use in Regulatory Guide 1.147, Revision 15, allows credit for essentially 100 percent coverage of the welds provided greater than 90 percent of the required volume has been examined.
- 4. Impracticality of Compliance Pursuant to 10 CFR 50.55a(g)(5)(iii), relief is requested from the essentially 100 percent volumetric examination coverage requirement for the subject weld due to the geometric configuration and permanent obstructions which limit the volumetric examination coverage of the subject welds.
These noted obstructions prevent achieving the essentially 100 percent volume examination coverage required by code.
The limitations and the actual examination coverage attained for each weld for which relief is requested are noted in Table 1.
to AEP-NRC-2012-2 Page 35 5, Burden Caused by Compliance To increase examination coverage on the subject welds requires removal of the permanently welded pads, supports, electrical supports, adjacent piping and nozzles or replacement of the heat exchanger with a design that would allow for complete examination coverage of the subject weld. This option to meet the 100 percent code examination requirement is considered impractical due to the cost, increased radiation exposure and impact to plant equipment.
6, Proposed Alternative and Basis for Use The subject welds received a volumetric examination utilizing the best available techniques on the accessible portions of welds to the extent practical. Additionally, a visual (VT-2) examination is performed during each inspection period during the system leakage tests as required by Section Xl, Table IWC-2500-1, Category C-H.
Based upon the examination volumes that were attained with acceptable results along with the visual (VT-2) examination performed each inspection period, it is reasonable to conclude that service induced degradation would be detected. Therefore, these proposed alternatives provide an acceptable level of quality and safety by providing reasonable assurance of structural integrity of the subject welds.
- 7. Period for Which Relief is Requested The relief is requested for the Third 10-year inspection interval for Donald C. Cook Nuclear Plant Units 1 and 2, which began on July 1, 1996, and ended April 9, 2010, at the conclusion of the Unit 1 Cycle 23 Refueling Outage. Significant long-term outages (greater than six months) occurred multiple times during the interval and the interval was extended as allowed by IWA-2430(e) and by IWA-2430(d) to accommodate interval planning and scheduling.
to AEP-NRC-2012-2 Page 36 Table 1 to Relief Request ISIR-38 Ultrasonic CNP Component Weld Item Examination Coverage Remarks Unit ID Description Number Attained (%)/
PDI (Y/N)
The completed examination was limited to 48.1%
coverage due to the configuration. The examination Shell to was single sided due to the proximity of the flange and 2 W-CTSHEX-2 Flange C1.10 48.1/Y its associated bolting. Exam limitation on the accessible side was due to the inlet and outlet nozzles restricting access for an 11" area of the weld. No relevant indications detected.
The completed examination was limited to 80.5%
Shell to Lower C80.5/N (per Article 4 of coverage due to the configuration. The examination 2 2-BIT-A SHell t01.20 8 (e rtic 4 limitation was due to four leg supports located along Head Section V) the weld from 0 degrees at 18"-26", 62"-70", 99"-107",
and 142"-150". No relevant indications detected.
The completed examination was limited to 85%
coverage due to the configuration. Examination Tube Sheet to 85.0/ N (per Article 4 of coverage was limited due to the proximity of welded Stub Barrel Section V) pads, nozzles, adjacent piping, hand hole openings, permanent support brackets and permanent electrical conduits. No relevant indications detected.
to AEP-NRC-2012-2 Page 37 RELIEF REQUEST ISIR-38 EXAMINATION CATEGORY C-A PRESSURE RETAINING WELDS IN PRESSURE VESSELS SUPPORTING DOCUMENTATION IS PROVIDED BY I&M LETTER DATED APRIL 8, 2011 ADAMS ACCESSION NO. ML11110A042 AND THE FOLLOWING TWO PAGES to AEP-NRC-2012-2 Page 38 LIMITATION SKETCH For FLANGE to SHELL WELD W-CTSHEX-2 to AEP-NRC-2012-2 Page 39
-/7INLE.T CONN.I t.F..ThL sr'o£5a..ccs'oL* _t,.
MATMLN .1*i,8 I
,'ITiL.-
.-_.G TO BF F- ^I,-F_.L.
rn7vp Limitations for Shell to Lower Head Weld 2-BIT-A to AEP-NRC-2012-2 Page 40 RELIEF REQUEST ISIR-39 EXAMINATION CATEGORY C-B PRESSURE RETAINING NOZZLE WELDS IN VESSELS to AEP-NRC-2012-2 Page 41 RELIEF REQUEST ISIR-39 Relief Request In Accordance with 10 CFR 50.55a(g)(5)(iii)
Inservice Inspection Impracticality
- 1. ASME Code Components Affected ASME Code Class: Code Class 2 Examination Category: C-B, Pressure Retaining Nozzle Welds in Vessels Item Numbers: C2.21, Nozzles Without Reinforcing Plate in Vessels > 1/ inch Nominal Thickness, Nozzle to Shell (or Head) Weld Component Identification: Listed in Table 1
2. Applicable Code Edition and Addenda
ASME Section Xl, 1989 Edition, No addenda
3. Applicable Code Requirement
ASME Section Xl, 1989 Edition, Examination Category C-B requires volumetric examination of 100 percent of the weld volume as defined in Table IWC-2500-1 and shown in Figures IWC-2500-4(a) or IWC-2500-4(b) as applicable. The alternative requirements of ASME Section Xl, Code Case N-460, approved for use in Regulatory Guide 1.147, Revision 15, allows credit for essentially 100 percent coverage of the welds provided greater than 90 percent of the required volume has been examined.
- 4. Impracticality of Compliance Pursuant to 10 CFR 50.55a(g)(5)(iii), relief is requested from the essentially 100 percent volumetric examination coverage requirement for the subject welds due to the geometric configuration and permanent obstructions which limits the volumetric examination coverage of the subject welds.
Due to the component geometry, coverage was limited due to tapers, bevels, weld contours, and joint configurations.
These noted obstructions prevent achieving the essentially 100 percent volume examination coverage required by code.
The limitations and the actual examination coverage attained for each weld for which relief is requested are noted in Table 1.
to AEP-NRC-2012-2 Page 42
- 5. Burden Caused by Compliance To increase examination coverage on the subject welds requires removal of significant portions of insulation and its supporting elements and redesign of the blend radius of the nozzle to shell weld with a design that would allow for complete examination coverage of the subject weld. This option to meet the 100 percent code examination requirement is considered impractical due to the cost, increased radiation exposure and impact to plant equipment.
- 6. Proposed Alternative and Basis for Use The subject welds received a volumetric examination utilizing the best available techniques on the accessible portions of welds to the extent practical. Additionally, a surface examination without any limitations was performed along with a visual (VT-2) examination that is performed during each inspection period during the system leakage tests as required by Section Xl, Table IWC-2500-1, Category C-H.
Based upon the examination volumes that were attained along with acceptable results and the acceptable surface examination that was performed and the visual (VT-2) examination performed each inspection period, it is reasonable to conclude that service induced degradation would be detected. Therefore, these proposed alternatives provide an acceptable level of quality and safety by providing reasonable assurance of structural integrity of the subject welds.
- 7. Period for Which Relief is Requested The relief is requested for the Third 10-year inspection interval for Donald C. Cook Nuclear Plant Units 1 and 2, which began on July 1, 1996, and ended April 9, 2010, at the conclusion of the Unit 1 Cycle 23 Refueling Outage. Significant long-term outages (greater than six months) occurred multiple times during the interval and the interval was extended as allowed by IWA-2430(e) and by IWA-2430(d) to accommodate interval planning and scheduling.
to AEP-NRC-2012-2 Page 43 Table 1 to Relief Request ISIR-39 Ultrasonic CNP Component Weld Item Examination Unit ID Description Number Coverage Attained Remarks PDI (Y/N)
The completed examination was limited to 46.5%
coverage due to the configuration. The coverage STM Nozzle to Shell C2.21 46.5/N (per Article 4 of limitation was due to the proximity of insulation and a FWN Section V) metal strap at top-dead-center and at bottom-dead-center due to the shell weld. No relevant indications detected.
to AEP-NRC-2012-2 Page 44 RELIEF REQUEST ISIR-39 EXAMINATION CATEGORY C-B PRESSURE RETAINING NOZZLE WELDS IN VESSELS SUPPORTING DOCUMENTATION IS PROVIDED BY I&M LETTER DATED APRIL 8, 2011 ADAMS ACCESSION NO. ML11110A042 to AEP-NRC-2012-2 Page 45 RELIEF REQUEST ISIR-40 EXAMINATION CATEGORY C-C INTEGRAL ATTACHMENTS FOR VESSELS, PIPING, PUMPS AND VALVES to AEP-NRC-2012-2 Page 46 RELIEF REQUEST ISIR-40 Relief Request In Accordance with 10 CFR 50.55a(g)(5)(iii)
Inservice Inspection Impracticality
- 1. ASME Code Components Affected ASME Code Class: Code Class 2 Examination Category: C-C, Integral Attachments for Vessels, Piping, Pumps and Valves Item Numbers: C3.20, Pumps, Integrally Welded Attachments C3.40, Valves, Integrally Welded Attachments Component Identification: Listed in Table 1
2. Applicable Code Edition and Addenda
ASME Section Xl, 1989 Edition, No addenda
3. Applicable Code Requirement
ASME Section Xl, 1989 Edition, Examination Category C-C requires surface examination of 100 percent of the weld as defined in Table IWC-2500-1 and shown in Figure IWC-2500-5.
The alternative requirements of ASME Section Xl, Code Case N-460, approved for use in Regulatory Guide 1.147, Revision 15, allows credit for essentially 100 percent coverage of the weld provided greater than 90 percent of the required area has been examined.
- 4. Impracticality of Compliance Pursuant to 10 CFR 50.55a(g)(5)(iii), relief is requested from the essentially 100 percent surface examination coverage requirement for the subject Weld due to the permanently attached support orientation and permanently embedded bolting obstructions which limits the surface examination coverage of the subject weld.
These noted obstructions prevent achieving the essentially 100 percent volume examination coverage required by code.
The limitations and the actual examination coverage attained for each weld for which relief is requested are noted in Table 1.
- 5. Burden Caused by Compliance To increase the examination coverage on the subject. weld requires removal of the permanent structural steel support member by physically cutting the support members apart and replacing the support members by re-welding following the completion of the surface examination. Removal of the permanently welded support members is considered to be to AEP-NRC-2012-2 Page 47 impractical based due to increased cost, potential for increased radiation exposure, and impact to plant equipment.
- 6. Proposed Alternative and Basis for Use The subject welds received a surface examination utilizing the best available techniques on the accessible portions of welds to the extent practical. Additionally, a visual (VT-2) examination is performed during each inspection period during the system leakage tests as required by Section Xl, Table IWC-2500-1, Category C-H.
Based upon the examination volumes that were attained along with acceptable results and the acceptable visual (VT-2) examination performed each inspection period, it is reasonable to conclude that service induced degradation would be detected. Therefore, these proposed alternatives provide an acceptable level of quality and safety by providing reasonable assurance of structural integrity of the subject welds.
- 7. Period for Which Relief is Requested The relief is requested for the Third 10-year inspection interval for Donald C. Cook Nuclear Plant Units 1 and 2, which began on July 1, 1996, and ended April 9, 2010, at the conclusion of the Unit 1 Cycle 23 Refueling Outage. Significant long-term outages (greater than six months) occurred multiple times during the interval and the interval was extended as allowed by IWA-2430(e) and by IWA-2430(d) to accommodate interval planning and scheduling.
to AEP-NRC-2012-2 Page 48 Table 1 to Relief Request ISIR-40 Ultrasonic Examination CNP Component Weld Item Covrage AtainetiRa Remarks Unit ID Description Number CoveragePDIAttained (Y/N)
Integrally The completed examination was limited to 64% due to 1-MS Welded C3.20 64/Not Applicable configuration. Base metal examinations were limited 11 S-PS Pipe due to inner and outer cooler interference. No Attachment relevant indications detected.
The completed examination was limited to 83.3%
coverage due to the configuration. The limitation on MSIV-MRV- Integrally the extent of the coverage for the bottom horizontal 230-S2 Welded 03.40 83.3/Not Applicable attachment weld was based on the orientation of the Support attached support in relation to the weld. No relevant indications detected.
to AEP-NRC-2012-2 Page 49 RELIEF REQUEST ISIR-40 EXAMINATION CATEGORY C-C INTEGRAL ATTACHMENTS FOR VESSELS, PIPING, PUMPS AND VALVES SUPPORTING DOCUMENTATION IS PROVIDED BY I&M LETTER DATED APRIL 8, 2011 ADAMS ACCESSION NO. ML11111OA042 to AEP-NRC-2012-2 Page 50 RELIEF REQUEST ISIR-41 EXAMINATION CATEGORY C-F-1 PRESSURE RETAINING WELDS IN AUSTENITIC STAINLESS STEEL OR HIGH ALLOY PIPING to AEP-NRC-2012-2 Page 51 RELIEF REQUEST ISIR-41 Relief Request In Accordance with 10 CFR 50.55a(g)(5)(iii)
Inservice Inspection Impracticality
- 1. ASME Code Components Affected ASME Code Class: Code Class 2 Examination Category: C-F-i, Item Numbers: C5.1 1, Piping Welds > 3/8 inch Nominal Wall Thickness for Piping
> NPS 4, Circumferential Weld C5.21, Piping Welds > 1/5 inch Nominal Wall Thickness for Piping
> NPS 2 and < NPS 4, Circumferential Weld Component Identification: Listed in Table 1
2. Applicable Code Edition and Addenda
ASME Section Xl, 1989 Edition, No addenda Austenitic piping welds with single side access subject to ultrasonic examination with Supplement 2 of Appendix VIll to the 1995 Edition with 1996 Addenda of ASME Section XI.
3. Applicable Code Requirement
ASME Section Xl, 1989 Edition, Examination Category C-F-1 requires volumetric examination of 100 percent of the weld volume as defined in Table IWC-2500-1 and shown in Figure IWC-2500-7. The alternative requirements of ASME Section Xl, Code Case N-460, approved for use in Regulatory Guide 1.147, Revision 15, allows credit for essentially 100 percent coverage of the welds provided greater than 90 percent of the required volume has been examined.
10 CFR 50.55a(b)(2)(xv)(A), requires the following examination coverage criteria when applying Supplement 2 to Appendix VIII:
(1) Piping must be examined in two axial directions and when examination in the circumferential direction is required, the circumferential examination must be performed in two directions, provided access is available.
(2) Where examination from both sides is not possible, full coverage credit may be claimed from a single side for ferritic welds. Where examination from both sides is not possible on austenitic welds, full coverage credit from a single side may be claimed only after completing a successful single sided Appendix VIII demonstration using flaws on the opposite side of the weld.
to AEP-NRC-2012-2 Page 52 10 CFR 50.55a(b)(2)(xvi)(B), requires that examinations performed from one side of a ferritic or stainless steel pipe weld must be conducted with equipment, procedures, and personnel that have demonstrated proficiency with single side examinations. To demonstrate equivalency to the two sided examinations, the demonstration must be performed to the requirements of Appendix VIII as modified by this paragraph and 10 CFR 50.55a(b)(2)(xv)(A).
- 4. Impracticality of Compliance Pursuant to 10 CFR 50.55a(g)(5)(iii), relief is requested from the essentially 100 percent volumetric examination coverage requirement for austenitic piping welds with single side access.
There are currently no Performance Demonstration Initiative (PDI) qualified single side examination procedures that demonstrate equivalency to two-sided examination procedures on austenitic piping welds. Current technology, is not capable of reliably detecting or sizing flaws on the far side of an austenitic weld for configurations common to United States nuclear applications.
PDI Performance Demonstration Qualification Summary (PDQS) certificates for austenitic piping list the limitation that single side examination is performed on a best effort basis. The best effort qualification is provided in place of a complete single side qualification to demonstrate that the examiners qualification and the subsequent weld examination is based on application of the best available technology.
When the examination area is limited to one side of an austenitic weld, examination coverage does not comply with 10 CFR 50.55a(b)(2)(xv)(A) and proficiency demonstrations do not comply with 10 CFR 50.55a(b)(2)(xvi)(B) and full coverage credit may not be claimed.
Based on the configuration limited to single side access, relief is requested from the essentially 100 percent surface examination coverage requirements for the subject piping welds listed in Table 1. Note that examination coverage listed is that attained during examination with no credit taken for the far side of each weld in which examination from that side could not be performed.
Pursuant to 10 CFR 50.55a(g)(5)(iii), relief is requested from the essentially 100 percent volumetric examination coverage requirement for the subject welds due to the geometric configuration and permanent obstructions which limit the volumetric examination coverage of the subject welds.
The limitations and the actual examination coverage attained for each weld for which relief is requested are noted in Table 1.
to AEP-NRC-2012-2 Page 53
- 5. Burden Caused by Compliance Compliance with code requirements requires extensive modification or replacement of components with a design that allows examination from both sides of the weld. This option to meet the required 100 percent volume examination coverage is considered impractical based on the cost, additional radiation exposure and impact to plant equipment.
- 6. Proposed Alternative and Basis for Use The subject welds received a volumetric examination to the maximum extent practical utilizing the best available techniques, as qualified through the Performance Demonstration Initiative (PDI) for Supplement 2 with demonstrated best effort for single sided examination, from the accessible side of the weld. Additionally, a surface examination without limitations was performed on each weld. Further, a visual (VT-2) examination is performed each inspection period during the system leakage tests as required by Section XI, Table IWC-2500-1, Category C-H.
Based upon the examination volumes that were obtained with acceptable results along with the completed surface examination and the visual (VT-2) examination performed each inspection period, it is reasonable to conclude that service induced degradation would be detected if present. Therefore, these proposed alternatives provide an acceptable level of quality and safety by providing reasonable assurance of structural integrity of the subject welds.
- 7. Period for Which Relief is Requested The relief is requested for the Third 10-year inspection interval for Donald C. Cook Nuclear Plant Units 1 and 2, which began on July 1, 1996, and ended April 9, 2010, at the conclusion of the Unit 1 Cycle 23 Refueling Outage. Significant long-term outages (greater than six months) occurred multiple times during the interval and the interval was extended as allowed by IWA-2430(e) and by IWA-2430(d) to accommodate interval planning and scheduling.
to AEP-NRC-2012-2 Page 54 Table 1 to Relief Request ISIR-41 Ultrasonic Examination ier Coverage Attained Remarks PDI (Y/N)
The completed examination was limited to 50%
1 50.0ON coverage due to the configuration. The flange side is limited by the O.D. contour and flange bolting. No relevant indications detected.
The completed examination was limited to 50%
coverage due to the configuration. The configuration 1 50.O/Y prevents examination from the pump side due to its severe taper and the proximity of the pump casing to the weld. No relevant indications detected.
The completed examination was limited to 78%
coverage due to the configuration. The configuration 1 78.O/Y prevents examination due to the welds location inside of the box restraint surrounding the pipe. No relevant indications detected.
The completed examination was limited to 50%
coverage due to the configuration. The configuration 1 50.O/Y prevents examination on the tee side due to the sharp bevel adjacent to the tee side weld toe. No relevant indications detected.
The completed examination was limited to 50%
coverage due to the configuration. The examination 1 50.0/Y limitation is caused by the OD bevel on the valve, which is in proximity to the weld toe on the valve side.
No relevant indications detected.
to AEP-NRC-2012-2 Page 55 Ultrasonic Examination Remarks CNP Component Weld Item Coverage Attained Unit ID Description Number (%)i PDI (YIN)
The completed examination was limited to 50%
coverage due to the configuration. Full coverage was 1 1-SI-34-1 1F Elbow to Valve C5.11 50.0/h not obtainable due to the bevel at the weld toe on the valve side of the weld. No relevant indications detected.
The completed examination was limited to 50%
2-(3TS coverage due to the configuration. The configuration 2 04F Pipe to Valve 05.11 50.0/Y prevents examination from the valve side due to its severe taper and close proximity of the valve to the weld. No relevant indications detected.
The completed examination was limited to 50%
coverage due to the configuration. The configuration 1-SI-1i1A- Flange to Elbow C5.21 50.0/ of the reducing elbow to flange leads to a limited 01S examination based on the taper of the flange face and its proximity to the weld. No relevant indications detected.
The completed examination was limited to 50%
coverage due to the configuration. The configuration 1 1-SI-1 1-01S Flange to Elbow C5.21 50./Y of the elbow to flange leads to a limited examination based on the taper of the flange face and its proximity to the weld. No relevant indications detected.
The completed examination was limited to 49%
coverage due to the configuration. The configuration prevents examination from the valve side due to its 1 1-SI-1 1-05F Pipe to Valve C5.21 49.0/Y severe taper and the close proximity of the valve. A portion of the pipe side is obstructed due to the proximity of the integrally welded pipe support. No relevant indications detected.
to AEP-NRC-2012-2 Page 56 Ultrasonic CNP Component Weld Item Examination Unit ID Description Number Coverage Attained Remarks PDI (Y/N)
The completed examination was limited to 50%
Penetration to coverage due to the configuration. The configuration 1-SI-74-01F Elbow C5.21 50.0/Y prevents examination from the penetration side due to the OD surface contour and the proximity of the penetration. No relevant indications detected.
The completed examination was limited to 50%
coverage due to the configuration. The configuration 2 2-SI-42-01S Flange to Elbow C5.21 50.0/Y prevents examination from the flange side due to its severe taper and close proximity of the flange taper to the weld. No relevant indications detected.
The completed examination was limited to 46.5%
coverage due to the configuration. The configuration prevents examination from the valve side due to its 2 2-SI-42-03F Pipe to Valve C5.21 46.5/Y severe taper and close proximity of the valve to the weld. Additionally, a portion of the examination area was obstructed due to a branch connection in the piping. No relevant indications detected.
The completed examination was limited to 50%
coverage due to the configuration. The configuration 2 2-SI-73-02S Elbow to Pipe C5.21 50.0/Y prevents examination from the elbow side due to its severe taper and close proximity of the elbow to the weld. No relevant indications detected.
The completed examination was limited to 50%
coverage due to the configuration. The configuration 2 2-SI-81-01F Valve to Elbow C5.21 50.0/Y prevents examination from the valve side due to its severe taper and close proximity of the valve to the weld. No relevant indications detected.
to AEP-NRC-2012-2 Page 57 RELIEF REQUEST ISIR-41 EXAMINATION CATEGORY C-F-1 PRESSURE RETAINING WELDS IN AUSTENITIC STAINLESS STEEL OR HIGH ALLOY PIPING SUPPORTING DOCUMENTATION IS PROVIDED BY I&M LETTER DATED APRIL 8, 2011 ADAMS ACCESSION NO. ML11110A042 AND THE FOLLOWING PAGE to AEP-NRC-2012-2 Page 58 1-SI-24-06F 1-SI-1 52N Pipe to Tee Check Valve Weld Location Sketch for 1-SI-24-06F to AEP-NRC-2012-2 Page 59 RELIEF REQUEST ISIR-42
. EXAMINATION CATEGORY R-A RISK INFORMED PIPING EXAMINATIONS to AEP-NRC-2012-2 Page 60 RELIEF REQUEST ISIR-42 Relief Request In Accordance with 10 CFR 50.55a(g)(5)(iii)
Inservice Inspection Impracticality
- 1. ASME Code Components Affected ASME Code Class: Code Class 1 and 2 Examination Category: R-A, Risk Informed Piping Examinations Item Numbers: R1. 11, Elements Subject to Thermal Fatigue R1.16, Elements Subject to Intergranular or Transgranular Stress Corrosion Cracking (IGSCC or TGSCC)
R1.20, Elements Not Subject to a Degradation Mechanism Component Identification: Listed in Table 1
2. Applicable Code Edition and Addenda
ASME Section Xl, 1989 Edition, No addenda Austenitic piping welds with single side access subject to ultrasonic examination with Supplement 2 of Appendix VIII to the 1995 Edition with 1996 Addenda of ASME Section XI.
3. Applicable Code Requirement
The examination requirements for Class 1 and 2 piping welds are governed by the Risk Informed Inservice Inspection program that was approved by the NRC in a Safety Evaluation Report dated September 28, 2007 (ADAMS Accession No. ML072620553). This program was developed in accordance with ASME Section Xl Code Case N-716, Alternative Piping Classification and Examination Requirements. Table 1, Examination Category R-A, of Code Case N-716 requires 100 percent of the examination location to be examined. The alternative requirements of ASME Section Xl, Code Case N-460, approved for use in Regulatory Guide 1.147, Revision 15, allow credit for essentially 100 percent coverage of the weld provided greater than 90 percent of the required volume has been examined.
10 CFR 50.55a(b)(2)(xv)(A), requires the following examination coverage when applying Supplement 2 to Appendix VIII:
(1) Piping must be examined in two axial directions and when examination in the circumferential direction is required, the circumferential examination must be performed in two directions, provided access is available.
(2) Where examination from both sides is not possible, full coverage credit may be claimed from a single side for ferritic welds. Where examination from both sides is not possible on austenitic welds, full coverage credit from a single side may be claimed only to AEP-NRC-2012-2 Page 61 after completing a successful single side Appendix VIII demonstration using flaws on the opposite side of the weld.
10 CFR 50.55a(b)(2)(xvi)(B), requires that examinations performed from one side of a stainless steel pipe weld must be conducted with equipment, procedures, and personnel that have demonstrated proficiency with single side examinations. To demonstrate equivalency to the two sided examinations, the demonstration must be performed to the requirements of Appendix VIII as modified by this paragraph and 10 CFR 50.55a(b)(2)(xv)(A).
- 4. Impracticality of Compliance Pursuant to 10 CFR 50.55a(g)(5)(iii), relief is requested from the 100 percent volumetric examination coverage requirement for austenitic piping welds with single side access.
There are currently no Performance Demonstration Initiative (PDI) qualified single side examination procedures that demonstrate equivalency to two-sided examination procedures on austenitic piping welds. Current technology is not capable of reliably detecting or sizing flaws on the far side of an austenitic weld for configurations common to United States nuclear applications.
PDI Performance Demonstration Qualification Summary (PDQS) certificates for austenitic piping list the limitation that single side examination is performed on a best effort basis. The best effort qualification is provided in place of a complete single side qualification to demonstrate that the examiners qualification and the subsequent weld examination is based on application of the best available technology.
When the examination area is limited to one side of an austenitic weld, examination coverage does not comply with 10 CFR 50.55a(b)(2)(xv)(A) and proficiency demonstrations do not comply with 10 CFR 50.55a(b)(2)(xvi)(B) and full coverage credit may not be claimed.
Based on the configuration limited to single side access, relief is requested on complying with the 100 percent required examination coverage for the piping welds listed in Table 1. Note that examination coverage listed is that which was obtained during examination with no credit taken for the far side of each weld when only single-sided access was attainable.
Other welds in Table 1 have physical limitations that prevented full access from both sides of the weld. These limitations include pipe support members, transition areas on elbows, tapers and other geometric interferences. Compliance with code requirements would require extensive modification or replacement of components with a design that allows examination from both sides of the weld.
- 5. Burden Caused by Compliance Compliance with code requirements requires extensive modification or replacement of components with a design that allows examination from both sides of the weld.
This option to meet the required 100 percent volume examination coverage is considered impractical based on the cost, additional radiation exposure and impact to plant equipment to AEP-NRC-2012-2 Page 62
- 6. Proposed Alternative and Basis for Use The subject welds received a volumetric examination to the maximum extent practical utilizing the best available techniques, as qualified through the Performance Demonstration Initiative (PDI) for Supplement 2 with demonstrated best effort for single sided examination, from the accessible side of the weld. Additionally, a surface examination without limitations was performed on each weld. Further, a visual (VT-2) examination is performed each inspection period during the system leakage tests as required by Section Xl, Table IWC-2500-1, Category C-H.
Based upon the examination volumes that were obtained with acceptable results along with the completed surface examination and the visual (VT-2) examination performed each inspection period, it is reasonable to conclude that service induced degradation would be detected if present. Therefore, these proposed alternatives provide an acceptable level of quality and safety by providing reasonable assurance of structural integrity of the subject welds.
- 7. Period for Which Relief is Requested The relief is requested for the Third 10-year inspection interval for Donald C. Cook Nuclear Plant Units 1 and 2, which began on July 1, 1996, and ended April 9, 2010, at the conclusion of the Unit 1 Cycle 23 Refueling Outage. Significant long-term outages (greater than six months) occurred multiple times during the interval and the interval was extended as allowed by IWA-2430(e) and by IWA-2430(d) to accommodate interval planning and scheduling.
to AEP-NRC-2012-2 Page 63 Table 1 to Relief Request ISIR-42 Coverage Attained (%)I Remarks PDI (Y/N)
The completed examination was limited to 50%
coverage due to the configuration. The exam 50.O0Y limitation was due to the geometry of the branch limiting access from the downstream side. No relevant indications detected.
The completed examination was limited to 50%
coverage due to the configuration. The configuration 50.O0Y prevents examination on the tee side, downstream, due to the sharp bevel adjacent to the tee side weld toe. No relevant indications detected.
The completed examination was limited to 50%
coverage due to the configuration. The configuration 50.0/Y prevents examination on the tee side due to the sharp bevel adjacent to the tee side weld toe. No relevant indications detected.
The completed examination was limited to 50%
coverage due to the configuration. The configuration 50.O0Y prevents examination on the tee side due to the sharp bevel adjacent to the tee side weld toe. No relevant indications detected.
The completed examination was limited to 50%
coverage due to the configuration. The configuration 50.0/Y prevents examination on the tee side due to the sharp bevel adjacent to the tee side weld toe. No relevant indications detected.
to AEP-NRC-2012-2 Page 64 CNP Component Weld Item Ultrasonic Examination ID Description Number Coverage Attained (%)I Remarks Unit PDI (Y/N)
The completed examination was limited to 36.8%
coverage due to the configuration. The configuration 2-SI-57-19 prevents examination on the tee side due to the sharp 2 (Class 1) Pipe to Tee R1.16 36.8/Y bevel adjacent to the tee side weld toe (single side exam = 50.0%). Additional coverage was missed due to the weld contour (13.2%). No relevant indications detected.
The completed examination was limited to 50.0%
2-SI-57-21 coverage due to the configuration. The configuration 2 (Class 1) Elbow to Tee RI. 16 50.0/Y prevents examination on the tee side due to the sharp bevel adjacent to the tee side weld toe (single side exam = 50.0%). No relevant indications detected.
The completed examination was limited to 50.0%
2-SI-56-18 coverage due to the configuration. The configuration 2 (Class 1 ) Elbow to Tee RI. 16 50.0/Y prevents examination on the tee side due to the sharp bevel adjacent to the tee side weld toe (single side exam = 50.0%). No relevant indications detected.
The completed examination was limited to 50%
1-SI-548- coverage due to the configuration. Full coverage was 1 45S (Class Valve to Pipe R1.20 50.0/Y not obtainable due to the bevel at the weld toe on the
- 1) valve side of the weld. No relevant indications detected.
The completed examination was limited to 50%
1-RH Elbow to coverage due to the configuration. Full coverage was 1 06F (Class Valve R1.20 50.0/ not obtainable due to the bevel at the weld toe on the
- 2) valve side of the weld. No relevant indications detected.
to AEP-NRC-2012-2 Page 65 CNP Component Weld CNP Wel Item ompnen Itm Ultrasonic Examination Cverge Ataied %)/Remarks Unit ID Description Number Coverage Attained (N)I PDI (YIN)
The completed examination was limited to 89.7%
1-RC-8-02S coverage due to the configuration. Full coverage was S (Class 1) Elbow to Pipe R1.20 89.7NY not obtainable due to the bevel at the weld toe on the valve side of the weld. No relevant indications detected.
The completed examination was limited to 50%
1-SI-29-26F coverage due to the configuration. Full coverage was I (Class 1) Elbow to Pipe R1.20 50.O/Y not valveobtainable side of due the toweld.
the bevel at the weld toe on the No relevant indications detected.
The completed examination was limited to 50%
1-SI-33-26F Nozzle to R1.20 50.0/ coverage due to the configuration. Full coverage was (Class 1) Elbow not obtainable due to the Nozzle taper at the weld toe.
No relevant indications detected.
The completed examination was limited to 50%
2-RC-22-24 Elbow to coverage due to the configuration. The configuration 2 (Class 1) Valve R1.20 50.0/Y prevents examination from the valve side due to the close proximity of the valve body to the weld. No relevant indications detected.
The completed examination was limited to 50%
2-RC-23-12 Elbow to coverage due to the configuration. The configuration 2 (Class 1) Valve R1.20 50.O/Y prevents examination from the valve side due to the close proximity of the valve body to the weld. No relevant indications detected.
The completed examination was limited to 50%
2-RC-24-09 Elbow to coverage due to the configuration. The configuration 2 (Class 1) Valve R1.20 50.0Y prevents examination from the valve side due to the close proximity of the valve body to the weld. No relevant indications detected.
to AEP-NRC-2012-2 Page 66 Item Ultrasonic Co nic Examination Exainatior CNP Component Weld Unit ID Description Number overage Attained)Remarks PDI (YIN) 2-SI-569- The completed examination was limited to 50%
2 49S (Class Tee to Pipe R1.20 50.0/N coverage due to the configuration. The configuration 12 prevents examination from the Socket Welded fitting side. No relevant indications detected.
2-SI-569- The completed examination was limited to 50%
2 53S (Class Elbow to Pipe R1.20 50.0/ coverage due to the configuration. The configuration
- 1) prevents examination from the Socket Welded fitting side. No relevant indications detected.
2-SI-569- The completed examination was limited to 50%
2 54S (Class Elbow to Pipe R1.20 50.O0Y coverage due to the configuration. The configuration prevents examination from the Socket Welded fitting
- 1) side. No relevant indications detected.
The completed examination was limited to 48.4%
coverage due to the configuration. The configuration 2-SI-57-22 prevents examination on the tee side due to the sharp 2 (Class 1) Tee to Pipe R1.16 48.4/Y bevel adjacent to the tee side weld toe (single side exam = 50.0%). Additional coverage was missed due to the weld contour (1.6%). No relevant indications detected.
The completed examination was limited to 66.2%
2-SI-56-10 coverage due to the configuration. The configuration 2 (Class 1) Pipe to Elbow R1.20 66.2NY prevents examination of 100% of the required area due to the presence of. a permanent support which limited access. No relevant indications detected.
The completed examination was limited to 50%
2-SI-78-01 Valve to coverage due to the configuration. The configuration 2 (Class 1) Elbow R1.20 50.0K prevents examination from the valve side due to its severe taper and close proximity of the valve to the weld. No relevant indications detected.
to AEP-NRC-2012-2 Page 67 Ultrasonic Examination a CNP Component Weld Item Covrage ExainatiR Unit ID Description Number Coverage Attained Remarks PDI (Y/N)
The completed examination was limited to 50%
2-SI-56-22 Elbow to coverage due to the configuration. The exam 2 (Class 1) Branch R1.20 50.0/Y limitation was due to the geometry of the branch limiting access from the upstream side. No relevant indications detected.
to AEP-NRC-2012-2 Page 68 RELIEF REQUEST ISIR-42 EXAMINATION CATEGORY R-A RISK INFORMED PIPING EXAMINATIONS SUPPORTING DOCUMENTATION IS PROVIDED BY I&M LETTER DATED APRIL 8, 2011 ADAMS ACCESSION NO. ML1111OA042 AND THE FOLLOWING THREE PAGES to AEP-NRC-2012-2 Page 69 (REF)
'. ý" Iýr .- I-to AEP-NRC-2012-2 Page 70 SUPPORT 2-GRC-S6e3 ON ELBOW -
(REF)
(REF) 3" SCH.
160 SMLS.
S. S PIPE DETAIL "B" LOOKING EAST Location of Elbow to Valve Weld 2-RC-23-12 to AEP-NRC-2012-2 Page 71 7
N, I I I I I I I A
Ad.
Location of Elbow to Valve Weld 2-RC-24-09