ML12092A001: Difference between revisions
StriderTol (talk | contribs) (Created page by program invented by StriderTol) |
StriderTol (talk | contribs) (Created page by program invented by StriderTol) |
||
(4 intermediate revisions by the same user not shown) | |||
Line 2: | Line 2: | ||
| number = ML12092A001 | | number = ML12092A001 | ||
| issue date = 03/27/2012 | | issue date = 03/27/2012 | ||
| title = | | title = NRR E-mail Capture - FW: ME7378 - Kewaunee - Relief Req RR-G-5-1 to -40 Request for Additional Information (RAI) | ||
| author name = Feintuch K | | author name = Feintuch K | ||
| author affiliation = NRC/NRR/DORL | | author affiliation = NRC/NRR/DORL | ||
| addressee name = Gadzala J, Sly C | | addressee name = Gadzala J, Sly C | ||
| addressee affiliation = Dominion Generation | | addressee affiliation = Dominion Generation | ||
| docket = 05000305 | | docket = 05000305 | ||
Line 18: | Line 18: | ||
=Text= | =Text= | ||
{{#Wiki_filter: | {{#Wiki_filter:NRR-PMDAPEm Resource From: Feintuch, Karl Sent: Tuesday, March 27, 2012 3:17 PM To: 'Jack Gadzala'; 'Craig D Sly' Cc: Rezai, Ali; McLellan, Thomas | ||
==Subject:== | ==Subject:== | ||
FW: ME7378 - Kewaunee - Relief Req RR-G-5-1 to -40 Request for Additional Information (RAI) Attachments: | FW: ME7378 - Kewaunee - Relief Req RR-G-5-1 to -40 Request for Additional Information (RAI) | ||
ME7378 TB RAI set EPNB McLellan, | Attachments: ME7378 TB RAI set EPNB McLellan, Rezai Re. 40 RRs 2012-03-27-1150 ET.docx This message is the same as that of 2:25 PM ET except that it corrects the format of Endnotes 1, 2, 3) that appear in section 2.6. | ||
From: Feintuch, Karl Sent: Tuesday, March 27, 2012 2:25 PM To: Jack Gadzala; 'Craig D Sly' Cc: Rezai, Ali; McLellan, Thomas | |||
From: Feintuch, Karl Sent: Tuesday, March 27, 2012 2:25 PM To: Jack Gadzala; 'Craig D Sly' Cc: Rezai, Ali; McLellan, Thomas | |||
==Subject:== | ==Subject:== | ||
ME7378 - Kewaunee - Relief Req RR-G-5-1 to -40 Request for Additional Information (RAI) | ME7378 - Kewaunee - Relief Req RR-G-5-1 to -40 Request for Additional Information (RAI) | ||
DRAFT REQUEST FOR ADDITIONAL INFORMATION ON THE FOURTH TEN YEAR 10-YEAR INSERVICE INSPECTION INTERVAL REQUEST FOR RELIEF RR-G-05 DOMINION ENERGY KEWAUNEE, INC. | DRAFT REQUEST FOR ADDITIONAL INFORMATION ON THE FOURTH TEN YEAR 10-YEAR INSERVICE INSPECTION INTERVAL REQUEST FOR RELIEF RR-G-05 DOMINION ENERGY KEWAUNEE, INC. | ||
KEWAUNEE POWER STATION DOCKET NUMBER: | KEWAUNEE POWER STATION DOCKET NUMBER: 50-305 1.0 SCOPE By letter dated September 28, 2011, the licensee, Dominion Energy Kewaunee, Inc. (DEK), submitted Request for Relief (RR) RR-G-05 from the requirements of the American Society of Mechanical Engineers (ASME) | ||
Boiler and Pressure Vessel Code, Section XI, Rules for Inservice Inspection of Nuclear Power Plant Components for Kewaunee Power Station (KPS). The request for relief applies to the fourth 10-year inservice inspection (ISI) interval, in which the licensee adopted the 1998 Edition through the 2000 Addenda of ASME Code Section XI as the code of record. | |||
In accordance with Title 10 of the Code of Federal Regulations (10 CFR) 50.55a(g)(5)(iii), the licensee has submitted the subject requests for relief for limited examinations in multiple ASME Code Examination Categories. The ASME Code requires that 100 percent of the examination volumes, or surface areas, described in ASME Code, Section XI, Tables IWB-2500 and IWC-2500 be performed during each interval. The licensee stated that 100 percent of the ASME Code-required volumes, or surface areas, are impractical to obtain at KPS. | |||
10 CFR 50.55a(g)(5)(iii) states that when licensees determine that conformance with ASME Code requirements is impractical at their facility, they shall submit information to support this determination. The U.S. Nuclear Regulatory Commission (NRC) will evaluate such requests based on impracticality, and may impose alternatives, giving due consideration to public safety and the burden imposed on the licensee. | |||
By letter dated September 28, 2011, the licensee, Dominion Energy Kewaunee, Inc. (DEK), submitted Request for Relief (RR) RR-G-05 from the requirements of the American Society of Mechanical Engineers (ASME) Boiler and Pressure Vessel Code, Section XI, Rules for Inservice Inspection of Nuclear Power Plant Components for Kewaunee Power Station (KPS). The request for relief applies to the fourth 10-year inservice inspection (ISI) interval, in which the licensee adopted the 1998 Edition through the 2000 Addenda of ASME Code Section XI as the code of record. | The NRC staff has reviewed the information submitted by the licensee, and based on this review, determined the following information is required to complete the evaluation. For clarity, the licensees requests have been evaluated according to ASME Code Examination Category and corresponding request for relief and have been labeled alphabetically. | ||
1 | |||
In accordance with Title 10 of the Code of Federal Regulations (10 CFR) 50.55a(g)(5)(iii), the licensee has submitted the subject requests for relief for limited examinations in multiple ASME Code Examination Categories. The ASME Code requires that 100 percent of the examination volumes, or surface areas, described in ASME Code, Section XI, Tables IWB-2500 and IWC-2500 be performed during each interval. The licensee stated that 100 percent of the ASME Code-required volumes, or surface areas, are impractical to | |||
obtain at KPS. | |||
10 CFR 50.55a(g)(5)(iii) states that when licensees determine that conformance with ASME Code requirements is impractical at their facility, they shall submit information to support this determination. The U.S. Nuclear Regulatory Commission (NRC) will evaluate such requests based on impracticality, and may impose alternatives, giving due consideration to public safety and the burden imposed on the licensee. | |||
The NRC staff has reviewed the information submitted by the licensee, and based on this review, determined the following information is required to complete the evaluation. For clarity, the | |||
below. | The request for information (RAI) is structured into 7 items (RAII). Each item is assigned a tracking number in the format: | ||
[TAC] - RAII - [Technical Branch] - [Primary Reviewer] - [Serial #] - [requested by year-month-day {nominally 30 days pending confirmation}]. For this request the assigned tracking numbers are listed in Section 2.0 below. | |||
A clarification conference call is | A clarification conference call is offered for any of the items. Some personnel attending for the NRC are in the Pacific Time Zone (PT). Therefore, phone calls are best held (Monday-Thursday afternoons ET) Please confirm the need for a clarification call any items by March 29, 2012, to facilitate scheduling of calls. These draft items become firm after clarification is confirmed by discussion prior to or at a clarification conference call. | ||
2.0 REQUEST FOR ADDITIONAL INFORMATION (RAI) | |||
FOR ADDITIONAL INFORMATION (RAI) | |||
The request consists of seven items: | The request consists of seven items: | ||
ME7378-RAII-EPNB-McL-2.1-2012-04-27 ME7378-RAII-EPNB-McL-2.2-2012-04-27 ME7378-RAII-EPNB-McL-2.3-2012-04-27 ME7378-RAII-EPNB-McL-2.4-2012-04-27 ME7378-RAII-EPNB-McL-2.5-2012-04-27 ME7378-RAII-EPNB-McL-2.6-2012-04-27 ME7378-RAII-EPNB-McL-2.7-2012-04-27 | ME7378-RAII-EPNB-McL-2.1-2012-04-27 ME7378-RAII-EPNB-McL-2.2-2012-04-27 ME7378-RAII-EPNB-McL-2.3-2012-04-27 ME7378-RAII-EPNB-McL-2.4-2012-04-27 ME7378-RAII-EPNB-McL-2.5-2012-04-27 ME7378-RAII-EPNB-McL-2.6-2012-04-27 ME7378-RAII-EPNB-McL-2.7-2012-04-27 In these tracking numbers: | ||
In these tracking numbers: | |||
EPNB = Piping and NDE Branch McL = Reviewers McLellan and , who is coordinating RAI traffic for TAC ME7378 2.n = 2.1 through 2.7 corresponding to the RAII shown in below. | EPNB = Piping and NDE Branch McL = Reviewers McLellan and , who is coordinating RAI traffic for TAC ME7378 2.n = 2.1 through 2.7 corresponding to the RAII shown in below. | ||
2012-04-27 = April 27, 2012, which is subject to confirmation with DEK that referenced items (RAII) are clear for response. | 2012-04-27 = April 27, 2012, which is subject to confirmation with DEK that referenced items (RAII) are clear for response. | ||
In your response please associate this tracking number and the RAII that follow (items 2.1 to 2.7) with each of your answers. | |||
2.1 General Information Required on Request for Relief RR-G-05 In Attachment 1 of the licensees submittal, DEK provided a general summary of the relief request. | |||
Under a section entitled ASME Code Requirements and the Basis for Relief, the licensee states the following: | |||
Volumetric and surface examinations of welds and base material will be examined in accordance with the applicable [ASME Code, Section XI,] Examination Category and Item Number and as required by the [KPS] Risk Informed Program. | |||
During the performance of scheduled examinations, there were numerous instances where examiners reported some type of interference. DEK personnel evaluated every instance where this situation was reported, and when possible, alternative examination areas were selected to avoid having to examine restricted areas. | |||
Piping welds that were selected that still necessitated limited examination (i.e. less than or equal to 90% coverage) were those included in the KPS Fourth Ten-Year Inservice Inspection program to ensure examinations were performed on a representative sample of piping welds and piping welds that were not previously examined during the first 30 years of plant operation. | |||
There are two risk informed program methodologies that are generally accepted for use by the NRC; they have been developed by the Electrical Power Research Institute (EPRI) and the Westinghouse Owners Group (WOG) and are documented in Topical Report TR-112657, Revised Risk-Informed 2 | |||
Inservice Inspection Evaluation Procedure, Revision B-A, and Topical Report WCAP-14572, Westinghouse Owners Group Application of Risk-Informed Methods to Piping Inservice Inspection Topical Report, Revision 1-NP-A, respectively. The two programs use either ASME Code Case N-578-1(Endnote 1), Risk-Informed Requirements for Class 1, 2 or 3 Piping, Method B Section XI, or Code Case N-577 (Endnote 1), Risk-Informed Requirements for Class 1, 2 or 3 Piping, Method A, both of which assign a new Examination Category R-A, listing welds, or other elements, according to expected forms of degradation. | |||
The ASME Categories and Item numbers included in the licensees current request for relief appear to be for a conventional ISI program, not a risk-informed program. However, as shown in the licensees statements above and in the data sheets provided for the specific welds listed under Category B-F, B-J, C-F-1, and C-F-2, the reviewer is lead to believe that these welds are part of a risk-informed program. | |||
Please clarify the type, either conventional ISI program or a RI-ISI program, to which each of the welds submitted for relief are included. If a RI-ISI program is being implemented, provide a reference to the NRC Safety Evaluation (SE) approving this program and to which methodology (WOG or EPRI) was followed. If a RI-ISI program is not being implemented, state why alternative piping welds that have not been previously examined during the first 30 years of plant operation were selected for examination during the fourth interval. | |||
Confirm the correct RI-ISI Examination Category and Item Numbers for each of the welds listed in Table 2.1.1 below. Specifically, if a RI-ISI program is being implemented, please list the RI-ISI R-A Item Numbers in accordance with the appropriate ASME Code Case or if KPS has an unique identifying RI-ISI system based on either RI-ISI ASME Code Case clarify how to identify the welds examined. | |||
Table 2.1.1 - Class 1 and 2 Piping Welds ASME Code Weld ID Weld Type Category Item B-F B5.40 PR-W1DM PZR 6 Nozzle-to-Safe End B-F B5.40 PR-W26DM PZR 6 Nozzle-to-Safe End B-F B5.40 RC-W67DM PZR 14 Nozzle-to-Safe End B-J B9.11 PR-W27 6 PZR Relief Circumferential Weld B-J B9.11 RC-W60 6 Reactor Coolant Circumferential Weld B-J B9.11 SI-W51 6 Safety Injection Circumferential Weld B-J B9.11 RHR-W9 8 Residual Heat Removal Circumferential Weld B-J B9.11 SI-W74 12 Safety Injection Circumferential Weld B-J B9.31 RC-W3BC 8 Reactor Coolant Pipe Branch Connection B-J B9.31 RC-W22BC 6 Reactor Coolant Pipe Branch Connection C-F-1 C5.13 ICS-W180 6 Containment Spray Circumferential Weld C-F-1 C5.13 ICS-W181 6 Containment Spray Circumferential Weld C-F-1 C5.13 RHR-W419 6 Residual Heat Removal Circumferential Weld C-F-1 C5.13 ICS-W45 8 Containment Spray Circumferential Weld C-F-1 C5.14 SI-W429 6 Safety Injection Circumferential Weld C-F-1 C5.21 SI-W249 3 Safety Injection circumferential Weld C-F-1 C5.21 AFW-W148 3 Auxiliary Feedwater Circumferential Weld C-F-1 C5.21 AFW-W151 3 Auxiliary Feedwater Circumferential Weld C-F-1 C5.21 AFW-W152 3 Auxiliary Feedwater Circumferential Weld C-F-1 C5.21 AFW-W155 3 Auxiliary Feedwater Circumferential Weld C-F-2 C5.61 AFW-W156 3 Auxiliary Feedwater Circumferential Weld C-F-2 C5.61 AFW-W171 3 Auxiliary Feedwater Circumferential Weld 3 | |||
Table 2.1.1 - Class 1 and 2 Piping Welds ASME Code Weld ID Weld Type Category Item C-F-2 C5.61 AFW-W172 3 Auxiliary Feedwater Circumferential Weld C-F-2 C5.61 AFW-W178 3 Auxiliary Feedwater Circumferential Weld C-F-2 C5.61 AFW-W189 3 Auxiliary Feedwater Circumferential Weld C-F-2 C5.61 AFW-W190 3 Auxiliary Feedwater Circumferential Weld C-F-2 C5.61 AFW-W191 3 Auxiliary Feedwater Circumferential Weld C-F-2 C5.61 AFW-W192 3 Auxiliary Feedwater Circumferential Weld C-F-2 C5.61 AFW-W194 3 Auxiliary Feedwater Circumferential Weld C-F-2 C5.61 AFW-W195 3 Auxiliary Feedwater Circumferential Weld C-F-2 C5.61 AFW-W196 3 Auxiliary Feedwater Circumferential Weld C-F-2 C5.61 AFW-W197 3 Auxiliary Feedwater Circumferential Weld C-F-2 C5.61 AFW-W198 3 Auxiliary Feedwater Circumferential Weld In addition, if the welds listed in Table 2.1.1 above were examined under a RI-ISI program: | |||
Table 2.1.1 - Class 1 and 2 Piping Welds ASME | |||
a) Please state the total number of Class 1 and Class 2 piping welds included in the overall risk-informed program so that the 33 limited examinations can be assessed within the scope of all examinations being implemented. | a) Please state the total number of Class 1 and Class 2 piping welds included in the overall risk-informed program so that the 33 limited examinations can be assessed within the scope of all examinations being implemented. | ||
b) Please confirm whether the ultrasonic (UT) examination methods for all piping welds listed in Table 2.1.1 were conducted in accordance with the performance demonstration requirements of ASME Code, Section XI, Appendix VIII. | b) Please confirm whether the ultrasonic (UT) examination methods for all piping welds listed in Table 2.1.1 were conducted in accordance with the performance demonstration requirements of ASME Code, Section XI, Appendix VIII. | ||
c) Further discuss whether additional welds could have been examined to augment the reduced volumetric coverage resulting from the limited examinations of the subject welds. | c) Further discuss whether additional welds could have been examined to augment the reduced volumetric coverage resulting from the limited examinations of the subject welds. | ||
d) Please state whether any alternative examination such as full surface examination was performed on each of the ASME Code Class 1 and Class 2 piping welds. The staff notes that surface examination is not required for most of the damage mechanisms listed in Table 1 of ASME Code Case N-577 or N-578. Also, please state whether any indications were discovered as a result of surface examinations. | d) Please state whether any alternative examination such as full surface examination was performed on each of the ASME Code Class 1 and Class 2 piping welds. The staff notes that surface examination is not required for most of the damage mechanisms listed in Table 1 of ASME Code Case N-577 or N-578. Also, please state whether any indications were discovered as a result of surface examinations. | ||
2.2 Request for Relief RR-G-05, Part A, ASME Code, Section XI, Examination Category B-D, Item B3.90, Full Penetration Welded Nozzles in Vessels Confirm that the UT examination methods used have been qualified in accordance with the performance demonstration requirements of ASME Section XI, Appendix VIII. | |||
2.3 Request for Relief RR-G-5, Part B, ASME Code, Section XI, Examination Category B-F, Item B5.40, Pressure Retaining Dissimilar Metal Welds In Vessel Nozzles The coverage percentages provided in the licensees submittal appear to be only from the 45- and 60-degree UT scans performed on the welds. Please state whether any additional best effort coverage was obtained using the 35-, 42-, and 50-degree L-wave scans, as applicable. | |||
for Relief RR-G-05, Part A, ASME Code, Section XI, Examination Category B-D, Item B3.90, Full Penetration Welded Nozzles in Vessels Confirm that the UT examination methods used have been qualified in accordance with the performance demonstration requirements of ASME Section XI, Appendix VIII. | 2.4 Request for Relief RR-G-5, Part C, ASME Code, Section XI, Examination Category B-J, Items B9.11 and B9.31, Pressure Retaining Welds in Piping The licensees submittal states that the subject weld areas in ASME Code, Section XI, Category B-J, Item B9.31 were interrogated with a combination of 34-, 45- and 60-degree shear waves. The licensees submittal further states that examinations were performed as single-sided examinations from the pipe side of the welds. | ||
4 | |||
for Relief RR-G-5, Part B, ASME Code, Section XI, Examination Category B-F, Item B5.40, Pressure Retaining Dissimilar Metal Welds In Vessel Nozzles The coverage percentages provided in the | |||
for Relief RR-G-5, Part C, ASME Code, Section XI, Examination Category B-J, Items B9.11 and B9.31, Pressure Retaining Welds in Piping | |||
The | |||
Confirm the insonification angles and wave modalities used to examine each of the subject welds in ASME Code, Section XI, Category B-J, Item B9.31. If only shear wave techniques were used to examine the subject stainless steel welds, please explain why refracted longitudinal wave techniques were not used as part of a best effort examination. The L-wave method has been shown capable of detecting planar inside diameter (ID) surface-breaking flaws on the far-side of wrought stainless steel welds. Recent studies (Endnotes 2, 3, 4) recommend the use of both shear and L-waves to obtain the best detection results, with minimum false calls, in austenitic welds. If both shear and L-waves were used please state the best effort coverage achieved on the near- and far-side of the subject weld volumes. | |||
2.5 Request for Relief RR-G-5, Part D, ASME Code, Section XI, Examination Category C-A, Items C1.10, C1.20, and C1.30, Pressure Retaining Welds in Class 2 Pressure Vessels State the materials of construction and the wall thickness for the pressure vessel welds submitted under ASME Code Category C-A. | |||
2.6 Request for Relief RR-G-5, Part E, ASME Code, Section XI, Examination Category C-F-1, Items C5.13, C5.14, and C5.21, Pressure Retaining Welds in Austenitic Stainless Steel or High Alloy Piping On the area where the required ISI examination coverage was not achieved, state whether any indications were discovered as a result of ASME Code-required preservice (ASME Code, Section XI, Category C-F-1, Item C5.21) volumetric (e.g., radiography) and surface examinations that were performed on the ASME Code Class 2 piping welds. | |||
State the wall thickness for the subject ASME Code Class 2 piping welds. | |||
Provide volumetric coverage sketches detailing the insonification angles and coverage each angle provides on each weld. | Provide volumetric coverage sketches detailing the insonification angles and coverage each angle provides on each weld. | ||
The | The licensees submittal states that the subject weld areas were interrogated with a combination of 45-, | ||
60-, and/or 70-degree shear waves. The licensees submittal further states that examinations were performed as single-sided examinations from the pipe side of the welds. | |||
Confirm the insonification angles and wave modalities used to examine each of the subject welds. If only shear wave techniques were used to examine the subject stainless steel welds and the pipe thickness were greater than 0.50-inches, please explain why refracted longitudinal wave techniques where not used as part of a | Confirm the insonification angles and wave modalities used to examine each of the subject welds. If only shear wave techniques were used to examine the subject stainless steel welds and the pipe thickness were greater than 0.50-inches, please explain why refracted longitudinal wave techniques where not used as part of a best effort examination. The L-wave method has been shown capable of detecting planar inside diameter (ID) surface-breaking flaws on the far-side of wrought stainless steel welds. Recent studies (Endnotes 1, 2, 3) recommend the use of both shear and L-waves to obtain the best detection results, with minimum false calls, in austenitic welds. If both shear and L-waves were used please state the best effort coverage achieved on the near- and far-side of the subject weld volumes. | ||
2.7 Request for Relief RR-G-5, Part F, ASME Code, Section XI, Examination Category C-F-2, Item C5.51, Pressure Retaining Welds in Carbon or Low Alloy Steel Piping On the area where the required ISI examination coverage was not achieved, state whether any indications were discovered as a result of ASME Code-required preservice volumetric (e.g., radiography) and surface examinations that were performed on the carbon steel piping welds. | |||
Endnotes | |||
for Relief RR-G-5, Part F, ASME Code, Section XI, Examination Category C-F-2, Item C5.51, Pressure Retaining Welds in Carbon or Low Alloy Steel Piping On the area where the required ISI examination coverage was not achieved, state whether any indications were discovered as a result of ASME Code-required preservice volumetric (e.g., radiography) and surface examinations that were performed on the carbon steel piping welds. | : 1. ASME Code Cases N-577-1 or N-578-1 are not approved for use in RG-1.147, Revision 16. Licensees base their RI-ISI inspection sample size and examination methodology on Table 1 of ASME Code Case N-577-1 or N-578-1. | ||
Endnotes | 5 | ||
: | : 2. F.V. Ammirato, X. Edelmann, and S.M. Walker, Examination of Dissimilar Metal Welds in BWR Nozzle-to-Safe End Joints, th 8 International Conference on NDE in the Nuclear Industry, ASM International, 1987. | ||
: 3. P. Lemaitre, T.D. Koble, and S.R. Doctor, PISC III Capability Study on Wrought-to-Wrought Austenitic Steel Welds: | |||
Evaluation at the Level of Procedures and Techniques, Effectiveness of Nondestructive Examination, Systems and Performance Demonstration, PVP-Volume 317, NDE-Volume 14, ASME, 1995. | |||
: 4. M.T. Anderson, A.A. Diaz, A.D. Cinson, S.L. Crawford, S.E. Cumblidge, S.R Doctor, K.M. Denslow, and S. Ahmed, 2011. An Assessment of Ultrasonic Techniques for Far-Side Examinations of Austenitic Stainless Steel Piping Welds, NUREG/CR-7113, PNNL-19353, U. S. Nuclear Regulatory Commission, Washington, DC. | |||
6 | |||
Hearing Identifier: | Hearing Identifier: NRR_PMDA Email Number: 311 Mail Envelope Properties (26E42474DB238C408C94990815A02F0968BB8EC2FD) | ||
==Subject:== | ==Subject:== | ||
FW: ME7378 - Kewaunee - Relief Req RR-G-5-1 to -40 Request for Additional Information (RAI) | FW: ME7378 - Kewaunee - Relief Req RR-G-5-1 to -40 Request for Additional Information (RAI) | ||
Tracking Status: None | Sent Date: 3/27/2012 3:17:03 PM Received Date: 3/27/2012 3:17:00 PM From: Feintuch, Karl Created By: Karl.Feintuch@nrc.gov Recipients: | ||
"Rezai, Ali" <Ali.Rezai@nrc.gov> | |||
Tracking Status: None "McLellan, Thomas" <Thomas.McLellan@nrc.gov> | |||
Tracking Status: None | |||
"'Jack Gadzala'" <jack.gadzala@dom.com> | |||
Tracking Status: None | |||
"'Craig D Sly'" <craig.d.sly@dom.com> | |||
Tracking Status: None Post Office: HQCLSTR01.nrc.gov Files Size Date & Time MESSAGE 17409 3/27/2012 3:17:00 PM ME7378 TB RAI set EPNB McLellan, Rezai Re. 40 RRs 2012-03-27-1150 ET.docx 42090 Options Priority: Standard Return Notification: No Reply Requested: No Sensitivity: Normal Expiration Date: | |||
Recipients Received: | |||
DRAFT REQUEST FOR ADDITIONAL INFORMATION ON THE FOURTH TEN YEAR 10-YEAR INSERVICE INSPECTION INTERVAL REQUEST FOR RELIEF RR-G-05 DOMINION ENERGY KEWAUNEE, INC. | DRAFT REQUEST FOR ADDITIONAL INFORMATION ON THE FOURTH TEN YEAR 10-YEAR INSERVICE INSPECTION INTERVAL REQUEST FOR RELIEF RR-G-05 DOMINION ENERGY KEWAUNEE, INC. | ||
KEWAUNEE POWER STATION DOCKET NUMBER: | KEWAUNEE POWER STATION DOCKET NUMBER: 50-305 1.0 SCOPE By letter dated September 28, 2011, the licensee, Dominion Energy Kewaunee, Inc. (DEK), | ||
submitted Request for Relief (RR) RR-G-05 from the requirements of the American Society of Mechanical Engineers (ASME) Boiler and Pressure Vessel Code, Section XI, Rules for Inservice Inspection of Nuclear Power Plant Components for Kewaunee Power Station (KPS). | |||
The request for relief applies to the fourth 10-year inservice inspection (ISI) interval, in which the licensee adopted the 1998 Edition through the 2000 Addenda of ASME Code Section XI as the code of record. | |||
By letter dated September 28, 2011, the licensee, Dominion Energy Kewaunee, Inc. (DEK), | In accordance with Title 10 of the Code of Federal Regulations (10 CFR) 50.55a(g)(5)(iii), the licensee has submitted the subject requests for relief for limited examinations in multiple ASME Code Examination Categories. The ASME Code requires that 100 percent of the examination volumes, or surface areas, described in ASME Code, Section XI, Tables IWB-2500 and IWC-2500 be performed during each interval. The licensee stated that 100 percent of the ASME Code-required volumes, or surface areas, are impractical to obtain at KPS. | ||
submitted Request for Relief (RR) RR-G-05 from the requirements of the American Society of Mechanical Engineers (ASME) Boiler and Pressure Vessel Code, Section XI, Rules for Inservice Inspection of Nuclear Power Plant Components for Kewaunee Power Station (KPS). The request for relief applies to the fourth 10-year inservice inspection (ISI) interval, in which the licensee adopted the 1998 Edition through the 2000 Addenda of ASME Code Section XI as the code of record. | |||
In accordance with Title 10 of the Code of Federal Regulations (10 CFR) 50.55a(g)(5)(iii), the licensee has submitted the subject requests for relief for limited examinations in multiple ASME Code Examination Categories. The ASME Code requires that 100 percent of the examination volumes, or surface areas, described in ASME Code, Section XI, Tables IWB-2500 and IWC-2500 be performed during each interval. The licensee stated that 100 percent of the ASME Code-required volumes, or surface areas, are impractical to obtain at KPS. | |||
10 CFR 50.55a(g)(5)(iii) states that when licensees determine that conformance with ASME Code requirements is impractical at their facility, they shall submit information to support this determination. The U.S. Nuclear Regulatory Commission (NRC) will evaluate such requests based on impracticality, and may impose alternatives, giving due consideration to public safety and the burden imposed on the licensee. | 10 CFR 50.55a(g)(5)(iii) states that when licensees determine that conformance with ASME Code requirements is impractical at their facility, they shall submit information to support this determination. The U.S. Nuclear Regulatory Commission (NRC) will evaluate such requests based on impracticality, and may impose alternatives, giving due consideration to public safety and the burden imposed on the licensee. | ||
The NRC staff has reviewed the information submitted by the licensee, and based on this review, determined the following information is required to complete the evaluation. For clarity, the | The NRC staff has reviewed the information submitted by the licensee, and based on this review, determined the following information is required to complete the evaluation. For clarity, the licensees requests have been evaluated according to ASME Code Examination Category and corresponding request for relief and have been labeled alphabetically. | ||
The request for information (RAI) is structured into 7 items (RAII). Each item is assigned a tracking number in the format: | |||
The request for information (RAI) is structured into 7 items (RAII). Each item is assigned a tracking number in the format: | [TAC] - RAII - [Technical Branch] - [Primary Reviewer] - [Serial #] - [requested by year-month-day {nominally 30 days pending confirmation}]. For this request the assigned tracking numbers are listed in Section 2.0 below. | ||
A clarification conference call is offered for any of the items. Some personnel attending for the NRC are in the Pacific Time Zone (PT). Therefore, phone calls are best held (Monday-Thursday afternoons ET) Please confirm the need for a clarification call any items by March 29, 2012, to facilitate scheduling of calls. These draft items become firm after clarification is confirmed by discussion prior to or at a clarification conference call. | |||
[TAC] - RAII - [Technical Branch] - [Primary Reviewer] - [Serial #] - [requested by year-month-day {nominally 30 days pending confirmation}]. For this request the assigned tracking numbers are listed in Section 2.0 below. | 2.0 REQUEST FOR ADDITIONAL INFORMATION (RAI) | ||
A clarification conference call is offered for any of the items. Some personnel attending for the NRC are in the Pacific Time Zone (PT). Therefore, phone calls are best held (Monday-Thursday afternoons ET) | |||
The request consists of seven items: | The request consists of seven items: | ||
ME7378-RAII-EPNB-McL-2.1-2012-04-27 ME7378-RAII-EPNB-McL-2.2-2012-04-27 ME7378-RAII-EPNB-McL-2.3-2012-04-27 ME7378-RAII-EPNB-McL-2.4-2012-04-27 ME7378-RAII-EPNB-McL-2.5-2012-04-27 ME7378-RAII-EPNB-McL-2.6-2012-04-27 ME7378-RAII-EPNB-McL-2.7-2012-04-27 | ME7378-RAII-EPNB-McL-2.1-2012-04-27 ME7378-RAII-EPNB-McL-2.2-2012-04-27 ME7378-RAII-EPNB-McL-2.3-2012-04-27 ME7378-RAII-EPNB-McL-2.4-2012-04-27 ME7378-RAII-EPNB-McL-2.5-2012-04-27 ME7378-RAII-EPNB-McL-2.6-2012-04-27 ME7378-RAII-EPNB-McL-2.7-2012-04-27 In these tracking numbers: | ||
In these tracking numbers: | |||
EPNB = Piping and NDE Branch McL = Reviewers McLellan and , who is coordinating RAI traffic for TAC ME7378 2.n = 2.1 through 2.7 corresponding to the RAII shown in below. | EPNB = Piping and NDE Branch McL = Reviewers McLellan and , who is coordinating RAI traffic for TAC ME7378 2.n = 2.1 through 2.7 corresponding to the RAII shown in below. | ||
2012-04-27 = April 27, 2012, which is subject to confirmation with DEK that referenced items (RAII) are clear for response. | 2012-04-27 = April 27, 2012, which is subject to confirmation with DEK that referenced items (RAII) are clear for response. | ||
In your response please associate this tracking number and the RAII that follow (items 2.1 to 2.7) with each of your answers. | |||
In your response please associate this tracking number and the RAII that follow (items 2.1 to 2.7) with each of your answers. | 2.1 General Information Required on Request for Relief RR-G-05 In Attachment 1 of the licensees submittal, DEK provided a general summary of the relief request. Under a section entitled ASME Code Requirements and the Basis for Relief, the licensee states the following: | ||
Volumetric and surface examinations of welds and base material will be examined in accordance with the applicable [ASME Code, Section XI,] | |||
Examination Category and Item Number and as required by the [KPS] Risk Informed Program. | |||
Information Required on Request for Relief RR-G-05 | During the performance of scheduled examinations, there were numerous instances where examiners reported some type of interference. DEK personnel evaluated every instance where this situation was reported, and when possible, alternative examination areas were selected to avoid having to examine restricted areas. | ||
In Attachment 1 of the | |||
Volumetric and surface examinations of welds and base material will be examined in accordance with the applicable [ASME Code, Section XI,] Examination Category and Item Number and as required by the [KPS] Risk Informed Program. During the performance of scheduled examinations, there were numerous instances where examiners reported some type of interference. DEK personnel evaluated every instance where this situation was reported, and when possible, alternative examination areas were selected to avoid having to examine restricted areas. | |||
Piping welds that were selected that still necessitated limited examination (i.e. | Piping welds that were selected that still necessitated limited examination (i.e. | ||
less than or equal to 90% coverage) were those included in the KPS Fourth Ten-Year Inservice Inspection program to ensure examinations were performed on a representative sample of piping welds and piping welds that were not previously examined during the first 30 years of plant operation. | less than or equal to 90% coverage) were those included in the KPS Fourth Ten-Year Inservice Inspection program to ensure examinations were performed on a representative sample of piping welds and piping welds that were not previously examined during the first 30 years of plant operation. | ||
There are two risk informed program methodologies that are generally accepted for use by the NRC; they have been developed by the Electrical Power Research Institute (EPRI) and the Westinghouse Owners Group (WOG) and are documented in Topical Report TR-112657, Revised Risk-Informed Inservice Inspection Evaluation Procedure, Revision B-A, and Topical Report WCAP-14572, Westinghouse Owners Group Application of Risk-Informed Methods to Piping Inservice Inspection Topical Report, | There are two risk informed program methodologies that are generally accepted for use by the NRC; they have been developed by the Electrical Power Research Institute (EPRI) and the Westinghouse Owners Group (WOG) and are documented in Topical Report TR-112657, Revised Risk-Informed Inservice Inspection Evaluation Procedure, Revision B-A, and Topical Report WCAP-14572, Westinghouse Owners Group Application of Risk-Informed Methods to Piping Inservice Inspection Topical Report, | ||
Confirm the correct RI-ISI Examination Category and Item Numbers for each of the welds listed in Table 2.1.1 below. Specifically, if a RI-ISI program is being implemented, please list the RI-ISI R-A Item Numbers in accordance with the appropriate ASME Code Case or if KPS has an unique identifying RI-ISI system based on either RI-ISI ASME | Revision 1-NP-A, respectively. The two programs use either ASME Code Case N-578-1(Endnote 1), Risk-Informed Requirements for Class 1, 2 or 3 Piping, Method B Section XI, or Code Case N-577 (Endnote 1), Risk-Informed Requirements for Class 1, 2 or 3 Piping, Method A, both of which assign a new Examination Category R-A, listing welds, or other elements, according to expected forms of degradation. | ||
The ASME Categories and Item numbers included in the licensees current request for relief appear to be for a conventional ISI program, not a risk-informed program. | |||
Code Case clarify how to identify the welds examined. | However, as shown in the licensees statements above and in the data sheets provided for the specific welds listed under Category B-F, B-J, C-F-1, and C-F-2, the reviewer is lead to believe that these welds are part of a risk-informed program. | ||
Table 2.1.1 - Class 1 and 2 Piping Welds ASME | Please clarify the type, either conventional ISI program or a RI-ISI program, to which each of the welds submitted for relief are included. If a RI-ISI program is being implemented, provide a reference to the NRC Safety Evaluation (SE) approving this program and to which methodology (WOG or EPRI) was followed. If a RI-ISI program is not being implemented, state why alternative piping welds that have not been previously examined during the first 30 years of plant operation were selected for examination during the fourth interval. | ||
Confirm the correct RI-ISI Examination Category and Item Numbers for each of the welds listed in Table 2.1.1 below. Specifically, if a RI-ISI program is being implemented, please list the RI-ISI R-A Item Numbers in accordance with the appropriate ASME Code Case or if KPS has an unique identifying RI-ISI system based on either RI-ISI ASME Code Case clarify how to identify the welds examined. | |||
Table 2.1.1 - Class 1 and 2 Piping Welds ASME Code Weld ID Weld Type Category Item B-F B5.40 PR-W1DM PZR 6 Nozzle-to-Safe End B-F B5.40 PR-W26DM PZR 6 Nozzle-to-Safe End B-F B5.40 RC-W67DM PZR 14 Nozzle-to-Safe End B-J B9.11 PR-W27 6 PZR Relief Circumferential Weld B-J B9.11 RC-W60 6 Reactor Coolant Circumferential Weld B-J B9.11 SI-W51 6 Safety Injection Circumferential Weld B-J B9.11 RHR-W9 8 Residual Heat Removal Circumferential Weld B-J B9.11 SI-W74 12 Safety Injection Circumferential Weld B-J B9.31 RC-W3BC 8 Reactor Coolant Pipe Branch Connection B-J B9.31 RC-W22BC 6 Reactor Coolant Pipe Branch Connection C-F-1 C5.13 ICS-W180 6 Containment Spray Circumferential Weld C-F-1 C5.13 ICS-W181 6 Containment Spray Circumferential Weld C-F-1 C5.13 RHR-W419 6 Residual Heat Removal Circumferential Weld C-F-1 C5.13 ICS-W45 8 Containment Spray Circumferential Weld | |||
Table 2.1.1 - Class 1 and 2 Piping Welds ASME Code Weld ID Weld Type Category Item C-F-1 C5.14 SI-W429 6 Safety Injection Circumferential Weld C-F-1 C5.21 SI-W249 3 Safety Injection circumferential Weld C-F-1 C5.21 AFW-W148 3 Auxiliary Feedwater Circumferential Weld C-F-1 C5.21 AFW-W151 3 Auxiliary Feedwater Circumferential Weld C-F-1 C5.21 AFW-W152 3 Auxiliary Feedwater Circumferential Weld C-F-1 C5.21 AFW-W155 3 Auxiliary Feedwater Circumferential Weld C-F-2 C5.61 AFW-W156 3 Auxiliary Feedwater Circumferential Weld C-F-2 C5.61 AFW-W171 3 Auxiliary Feedwater Circumferential Weld C-F-2 C5.61 AFW-W172 3 Auxiliary Feedwater Circumferential Weld C-F-2 C5.61 AFW-W178 3 Auxiliary Feedwater Circumferential Weld C-F-2 C5.61 AFW-W189 3 Auxiliary Feedwater Circumferential Weld C-F-2 C5.61 AFW-W190 3 Auxiliary Feedwater Circumferential Weld C-F-2 C5.61 AFW-W191 3 Auxiliary Feedwater Circumferential Weld C-F-2 C5.61 AFW-W192 3 Auxiliary Feedwater Circumferential Weld C-F-2 C5.61 AFW-W194 3 Auxiliary Feedwater Circumferential Weld C-F-2 C5.61 AFW-W195 3 Auxiliary Feedwater Circumferential Weld C-F-2 C5.61 AFW-W196 3 Auxiliary Feedwater Circumferential Weld C-F-2 C5.61 AFW-W197 3 Auxiliary Feedwater Circumferential Weld C-F-2 C5.61 AFW-W198 3 Auxiliary Feedwater Circumferential Weld In addition, if the welds listed in Table 2.1.1 above were examined under a RI-ISI program: | |||
a) Please state the total number of Class 1 and Class 2 piping welds included in the overall risk-informed program so that the 33 limited examinations can be assessed within the scope of all examinations being implemented. | |||
b) Please confirm whether the ultrasonic (UT) examination methods for all piping welds listed in Table 2.1.1 were conducted in accordance with the performance demonstration requirements of ASME Code, Section XI, Appendix VIII. | b) Please confirm whether the ultrasonic (UT) examination methods for all piping welds listed in Table 2.1.1 were conducted in accordance with the performance demonstration requirements of ASME Code, Section XI, Appendix VIII. | ||
c) Further discuss whether additional welds could have been examined to augment the reduced volumetric coverage resulting from the limited examinations of the subject | c) Further discuss whether additional welds could have been examined to augment the reduced volumetric coverage resulting from the limited examinations of the subject welds. | ||
d) Please state whether any alternative examination such as full surface examination was performed on each of the ASME Code Class 1 and Class 2 piping welds. The staff notes that surface examination is not required for most of the damage mechanisms listed in Table 1 of ASME Code Case N-577 or N-578. Also, please state whether any indications were discovered as a result of surface examinations. | |||
2.2 Request for Relief RR-G-05, Part A, ASME Code, Section XI, Examination Category B-D, Item B3.90, Full Penetration Welded Nozzles in Vessels Confirm that the UT examination methods used have been qualified in accordance with the performance demonstration requirements of ASME Section XI, Appendix VIII. | |||
2.3 Request for Relief RR-G-5, Part B, ASME Code, Section XI, Examination Category B-F, Item B5.40, Pressure Retaining Dissimilar Metal Welds In Vessel Nozzles The coverage percentages provided in the licensees submittal appear to be only from the 45- and 60-degree UT scans performed on the welds. Please state whether any additional best effort coverage was obtained using the 35-, 42-, and 50-degree L-wave scans, as applicable. | |||
2.4 Request for Relief RR-G-5, Part C, ASME Code, Section XI, Examination Category B-J, Items B9.11 and B9.31, Pressure Retaining Welds in Piping The licensees submittal states that the subject weld areas in ASME Code, Section XI, Category B-J, Item B9.31 were interrogated with a combination of 34-, 45- and 60-degree shear waves. The licensees submittal further states that examinations were performed as single-sided examinations from the pipe side of the welds. | |||
for Relief RR-G-5, Part B, ASME Code, Section XI, Examination Category B-F, Item B5.40, Pressure Retaining Dissimilar Metal Welds In Vessel Nozzles | Confirm the insonification angles and wave modalities used to examine each of the subject welds in ASME Code, Section XI, Category B-J, Item B9.31. If only shear wave techniques were used to examine the subject stainless steel welds, please explain why refracted longitudinal wave techniques were not used as part of a best effort examination. The L-wave method has been shown capable of detecting planar inside diameter (ID) surface-breaking flaws on the far-side of wrought stainless steel welds. | ||
Recent studies (Endnotes 2, 3, 4) recommend the use of both shear and L-waves to obtain the best detection results, with minimum false calls, in austenitic welds. If both shear and L-waves were used please state the best effort coverage achieved on the near- and far-side of the subject weld volumes. | |||
The coverage percentages provided in the | 2.5 Request for Relief RR-G-5, Part D, ASME Code, Section XI, Examination Category C-A, Items C1.10, C1.20, and C1.30, Pressure Retaining Welds in Class 2 Pressure Vessels State the materials of construction and the wall thickness for the pressure vessel welds submitted under ASME Code Category C-A. | ||
2.6 Request for Relief RR-G-5, Part E, ASME Code, Section XI, Examination Category C-F-1, Items C5.13, C5.14, and C5.21, Pressure Retaining Welds in Austenitic Stainless Steel or High Alloy Piping On the area where the required ISI examination coverage was not achieved, state whether any indications were discovered as a result of ASME Code-required preservice (ASME Code, Section XI, Category C-F-1, Item C5.21) volumetric (e.g., radiography) and surface examinations that were performed on the ASME Code Class 2 piping welds. | |||
for Relief RR-G-5, Part C, ASME Code, Section XI, Examination Category B-J, Items B9.11 and B9.31, Pressure Retaining Welds in Piping The | |||
Confirm the insonification angles and wave modalities used to examine each of the subject welds in ASME Code, Section XI, Category B-J, Item B9.31. If only shear wave techniques were used to examine the subject stainless steel welds, please explain why refracted longitudinal wave techniques were not used as part of a | |||
for Relief RR-G-5, Part D, ASME Code, Section XI, Examination Category C-A, Items C1.10, C1.20, and C1.30, Pressure Retaining Welds in Class 2 Pressure Vessels | |||
State the materials of construction and the wall thickness for the pressure vessel welds submitted under ASME Code Category C-A. | |||
for Relief RR-G-5, Part E, ASME Code, Section XI, Examination Category C-F-1, Items C5.13, C5.14, and C5.21, Pressure Retaining Welds in Austenitic Stainless Steel or High Alloy Piping | |||
On the area where the required ISI examination coverage was not achieved, state whether any indications were discovered as a result of ASME Code-required preservice (ASME Code, Section XI, Category C-F-1, Item C5.21) volumetric (e.g., radiography) and surface examinations that were performed on the | |||
State the wall thickness for the subject ASME Code Class 2 piping welds. | |||
Provide volumetric coverage sketches detailing the insonification angles and coverage each angle provides on each weld. | Provide volumetric coverage sketches detailing the insonification angles and coverage each angle provides on each weld. | ||
The | The licensees submittal states that the subject weld areas were interrogated with a combination of 45-, 60-, and/or 70-degree shear waves. The licensees submittal further states that examinations were performed as single-sided examinations from the pipe side of the welds. | ||
Confirm the insonification angles and wave modalities used to examine each of the subject welds. If only shear wave techniques were used to examine the subject stainless steel welds and the pipe thickness were greater than 0.50-inches, please explain why refracted longitudinal wave techniques where not used as part of a best effort examination. The L-wave method has been shown capable of detecting planar inside diameter (ID) surface-breaking flaws on the far-side of wrought stainless steel welds. Recent studies (Endnotes 1, 2, 3) recommend the use of both shear and L-waves to obtain the best detection results, with minimum false calls, in austenitic welds. | |||
Confirm the insonification angles and wave modalities used to examine each of the subject welds. If only shear wave techniques were used to examine the subject stainless steel welds and the pipe thickness were greater than 0.50-inches, please explain why refracted longitudinal wave techniques where not used as part of a | If both shear and L-waves were used please state the best effort coverage achieved on the near- and far-side of the subject weld volumes. | ||
If both shear and L-waves were used please state the | 2.7 Request for Relief RR-G-5, Part F, ASME Code, Section XI, Examination Category C-F-2, Item C5.51, Pressure Retaining Welds in Carbon or Low Alloy Steel Piping On the area where the required ISI examination coverage was not achieved, state whether any indications were discovered as a result of ASME Code-required preservice volumetric (e.g., radiography) and surface examinations that were performed on the carbon steel piping welds. | ||
Endnotes | |||
: 1. ASME Code Cases N-577-1 or N-578-1 are not approved for use in RG-1.147, Revision 16. Licensees base their RI-ISI inspection sample size and examination methodology on Table 1 of ASME Code Case N-577-1 or N-578-1. | |||
for Relief RR-G-5, Part F, ASME Code, Section XI, Examination Category C-F-2, Item C5.51, Pressure Retaining Welds in Carbon or Low Alloy Steel Piping On the area where the required ISI examination coverage was not achieved, state whether any indications were discovered as a result of ASME Code-required preservice volumetric (e.g., radiography) and surface examinations that were performed on the carbon steel piping welds. | : 2. F.V. Ammirato, X. Edelmann, and S.M. Walker, Examination of Dissimilar Metal Welds in BWR Nozzle-to-th Safe End Joints, 8 International Conference on NDE in the Nuclear Industry, ASM International, 1987. | ||
: 3. P. Lemaitre, T.D. Koble, and S.R. Doctor, PISC III Capability Study on Wrought-to-Wrought Austenitic Steel Welds: Evaluation at the Level of Procedures and Techniques, Effectiveness of Nondestructive Examination, Systems and Performance Demonstration, PVP-Volume 317, NDE-Volume 14, ASME, 1995. | |||
Endnotes | : 4. M.T. Anderson, A.A. Diaz, A.D. Cinson, S.L. Crawford, S.E. Cumblidge, S.R Doctor, K.M. Denslow, and S. | ||
: 1. ASME Code Cases N-577-1 or N-578-1 are not approved for use in RG-1.147, Revision 16. Licensees base their RI-ISI inspection sample size and examination methodology on Table 1 of ASME Code Case N-577-1 or N-578-1. 2. F.V. Ammirato, | Ahmed, 2011. An Assessment of Ultrasonic Techniques for Far-Side Examinations of Austenitic Stainless Steel Piping Welds, NUREG/CR-7113, PNNL-19353, U. S. Nuclear Regulatory Commission, Washington, DC.}} |
Latest revision as of 21:38, 5 December 2019
ML12092A001 | |
Person / Time | |
---|---|
Site: | Kewaunee |
Issue date: | 03/27/2012 |
From: | Feintuch K Division of Operating Reactor Licensing |
To: | Gadzala J, Sly C Dominion Generation |
References | |
TAC ME7378 | |
Download: ML12092A001 (13) | |
Text
NRR-PMDAPEm Resource From: Feintuch, Karl Sent: Tuesday, March 27, 2012 3:17 PM To: 'Jack Gadzala'; 'Craig D Sly' Cc: Rezai, Ali; McLellan, Thomas
Subject:
FW: ME7378 - Kewaunee - Relief Req RR-G-5-1 to -40 Request for Additional Information (RAI)
Attachments: ME7378 TB RAI set EPNB McLellan, Rezai Re. 40 RRs 2012-03-27-1150 ET.docx This message is the same as that of 2:25 PM ET except that it corrects the format of Endnotes 1, 2, 3) that appear in section 2.6.
From: Feintuch, Karl Sent: Tuesday, March 27, 2012 2:25 PM To: Jack Gadzala; 'Craig D Sly' Cc: Rezai, Ali; McLellan, Thomas
Subject:
ME7378 - Kewaunee - Relief Req RR-G-5-1 to -40 Request for Additional Information (RAI)
DRAFT REQUEST FOR ADDITIONAL INFORMATION ON THE FOURTH TEN YEAR 10-YEAR INSERVICE INSPECTION INTERVAL REQUEST FOR RELIEF RR-G-05 DOMINION ENERGY KEWAUNEE, INC.
KEWAUNEE POWER STATION DOCKET NUMBER: 50-305 1.0 SCOPE By letter dated September 28, 2011, the licensee, Dominion Energy Kewaunee, Inc. (DEK), submitted Request for Relief (RR) RR-G-05 from the requirements of the American Society of Mechanical Engineers (ASME)
Boiler and Pressure Vessel Code,Section XI, Rules for Inservice Inspection of Nuclear Power Plant Components for Kewaunee Power Station (KPS). The request for relief applies to the fourth 10-year inservice inspection (ISI) interval, in which the licensee adopted the 1998 Edition through the 2000 Addenda of ASME Code Section XI as the code of record.
In accordance with Title 10 of the Code of Federal Regulations (10 CFR) 50.55a(g)(5)(iii), the licensee has submitted the subject requests for relief for limited examinations in multiple ASME Code Examination Categories. The ASME Code requires that 100 percent of the examination volumes, or surface areas, described in ASME Code,Section XI, Tables IWB-2500 and IWC-2500 be performed during each interval. The licensee stated that 100 percent of the ASME Code-required volumes, or surface areas, are impractical to obtain at KPS.
10 CFR 50.55a(g)(5)(iii) states that when licensees determine that conformance with ASME Code requirements is impractical at their facility, they shall submit information to support this determination. The U.S. Nuclear Regulatory Commission (NRC) will evaluate such requests based on impracticality, and may impose alternatives, giving due consideration to public safety and the burden imposed on the licensee.
The NRC staff has reviewed the information submitted by the licensee, and based on this review, determined the following information is required to complete the evaluation. For clarity, the licensees requests have been evaluated according to ASME Code Examination Category and corresponding request for relief and have been labeled alphabetically.
1
The request for information (RAI) is structured into 7 items (RAII). Each item is assigned a tracking number in the format:
[TAC] - RAII - [Technical Branch] - [Primary Reviewer] - [Serial #] - [requested by year-month-day {nominally 30 days pending confirmation}]. For this request the assigned tracking numbers are listed in Section 2.0 below.
A clarification conference call is offered for any of the items. Some personnel attending for the NRC are in the Pacific Time Zone (PT). Therefore, phone calls are best held (Monday-Thursday afternoons ET) Please confirm the need for a clarification call any items by March 29, 2012, to facilitate scheduling of calls. These draft items become firm after clarification is confirmed by discussion prior to or at a clarification conference call.
2.0 REQUEST FOR ADDITIONAL INFORMATION (RAI)
The request consists of seven items:
ME7378-RAII-EPNB-McL-2.1-2012-04-27 ME7378-RAII-EPNB-McL-2.2-2012-04-27 ME7378-RAII-EPNB-McL-2.3-2012-04-27 ME7378-RAII-EPNB-McL-2.4-2012-04-27 ME7378-RAII-EPNB-McL-2.5-2012-04-27 ME7378-RAII-EPNB-McL-2.6-2012-04-27 ME7378-RAII-EPNB-McL-2.7-2012-04-27 In these tracking numbers:
EPNB = Piping and NDE Branch McL = Reviewers McLellan and , who is coordinating RAI traffic for TAC ME7378 2.n = 2.1 through 2.7 corresponding to the RAII shown in below.
2012-04-27 = April 27, 2012, which is subject to confirmation with DEK that referenced items (RAII) are clear for response.
In your response please associate this tracking number and the RAII that follow (items 2.1 to 2.7) with each of your answers.
2.1 General Information Required on Request for Relief RR-G-05 In Attachment 1 of the licensees submittal, DEK provided a general summary of the relief request.
Under a section entitled ASME Code Requirements and the Basis for Relief, the licensee states the following:
Volumetric and surface examinations of welds and base material will be examined in accordance with the applicable [ASME Code,Section XI,] Examination Category and Item Number and as required by the [KPS] Risk Informed Program.
During the performance of scheduled examinations, there were numerous instances where examiners reported some type of interference. DEK personnel evaluated every instance where this situation was reported, and when possible, alternative examination areas were selected to avoid having to examine restricted areas.
Piping welds that were selected that still necessitated limited examination (i.e. less than or equal to 90% coverage) were those included in the KPS Fourth Ten-Year Inservice Inspection program to ensure examinations were performed on a representative sample of piping welds and piping welds that were not previously examined during the first 30 years of plant operation.
There are two risk informed program methodologies that are generally accepted for use by the NRC; they have been developed by the Electrical Power Research Institute (EPRI) and the Westinghouse Owners Group (WOG) and are documented in Topical Report TR-112657, Revised Risk-Informed 2
Inservice Inspection Evaluation Procedure, Revision B-A, and Topical Report WCAP-14572, Westinghouse Owners Group Application of Risk-Informed Methods to Piping Inservice Inspection Topical Report, Revision 1-NP-A, respectively. The two programs use either ASME Code Case N-578-1(Endnote 1), Risk-Informed Requirements for Class 1, 2 or 3 Piping, Method B Section XI, or Code Case N-577 (Endnote 1), Risk-Informed Requirements for Class 1, 2 or 3 Piping, Method A, both of which assign a new Examination Category R-A, listing welds, or other elements, according to expected forms of degradation.
The ASME Categories and Item numbers included in the licensees current request for relief appear to be for a conventional ISI program, not a risk-informed program. However, as shown in the licensees statements above and in the data sheets provided for the specific welds listed under Category B-F, B-J, C-F-1, and C-F-2, the reviewer is lead to believe that these welds are part of a risk-informed program.
Please clarify the type, either conventional ISI program or a RI-ISI program, to which each of the welds submitted for relief are included. If a RI-ISI program is being implemented, provide a reference to the NRC Safety Evaluation (SE) approving this program and to which methodology (WOG or EPRI) was followed. If a RI-ISI program is not being implemented, state why alternative piping welds that have not been previously examined during the first 30 years of plant operation were selected for examination during the fourth interval.
Confirm the correct RI-ISI Examination Category and Item Numbers for each of the welds listed in Table 2.1.1 below. Specifically, if a RI-ISI program is being implemented, please list the RI-ISI R-A Item Numbers in accordance with the appropriate ASME Code Case or if KPS has an unique identifying RI-ISI system based on either RI-ISI ASME Code Case clarify how to identify the welds examined.
Table 2.1.1 - Class 1 and 2 Piping Welds ASME Code Weld ID Weld Type Category Item B-F B5.40 PR-W1DM PZR 6 Nozzle-to-Safe End B-F B5.40 PR-W26DM PZR 6 Nozzle-to-Safe End B-F B5.40 RC-W67DM PZR 14 Nozzle-to-Safe End B-J B9.11 PR-W27 6 PZR Relief Circumferential Weld B-J B9.11 RC-W60 6 Reactor Coolant Circumferential Weld B-J B9.11 SI-W51 6 Safety Injection Circumferential Weld B-J B9.11 RHR-W9 8 Residual Heat Removal Circumferential Weld B-J B9.11 SI-W74 12 Safety Injection Circumferential Weld B-J B9.31 RC-W3BC 8 Reactor Coolant Pipe Branch Connection B-J B9.31 RC-W22BC 6 Reactor Coolant Pipe Branch Connection C-F-1 C5.13 ICS-W180 6 Containment Spray Circumferential Weld C-F-1 C5.13 ICS-W181 6 Containment Spray Circumferential Weld C-F-1 C5.13 RHR-W419 6 Residual Heat Removal Circumferential Weld C-F-1 C5.13 ICS-W45 8 Containment Spray Circumferential Weld C-F-1 C5.14 SI-W429 6 Safety Injection Circumferential Weld C-F-1 C5.21 SI-W249 3 Safety Injection circumferential Weld C-F-1 C5.21 AFW-W148 3 Auxiliary Feedwater Circumferential Weld C-F-1 C5.21 AFW-W151 3 Auxiliary Feedwater Circumferential Weld C-F-1 C5.21 AFW-W152 3 Auxiliary Feedwater Circumferential Weld C-F-1 C5.21 AFW-W155 3 Auxiliary Feedwater Circumferential Weld C-F-2 C5.61 AFW-W156 3 Auxiliary Feedwater Circumferential Weld C-F-2 C5.61 AFW-W171 3 Auxiliary Feedwater Circumferential Weld 3
Table 2.1.1 - Class 1 and 2 Piping Welds ASME Code Weld ID Weld Type Category Item C-F-2 C5.61 AFW-W172 3 Auxiliary Feedwater Circumferential Weld C-F-2 C5.61 AFW-W178 3 Auxiliary Feedwater Circumferential Weld C-F-2 C5.61 AFW-W189 3 Auxiliary Feedwater Circumferential Weld C-F-2 C5.61 AFW-W190 3 Auxiliary Feedwater Circumferential Weld C-F-2 C5.61 AFW-W191 3 Auxiliary Feedwater Circumferential Weld C-F-2 C5.61 AFW-W192 3 Auxiliary Feedwater Circumferential Weld C-F-2 C5.61 AFW-W194 3 Auxiliary Feedwater Circumferential Weld C-F-2 C5.61 AFW-W195 3 Auxiliary Feedwater Circumferential Weld C-F-2 C5.61 AFW-W196 3 Auxiliary Feedwater Circumferential Weld C-F-2 C5.61 AFW-W197 3 Auxiliary Feedwater Circumferential Weld C-F-2 C5.61 AFW-W198 3 Auxiliary Feedwater Circumferential Weld In addition, if the welds listed in Table 2.1.1 above were examined under a RI-ISI program:
a) Please state the total number of Class 1 and Class 2 piping welds included in the overall risk-informed program so that the 33 limited examinations can be assessed within the scope of all examinations being implemented.
b) Please confirm whether the ultrasonic (UT) examination methods for all piping welds listed in Table 2.1.1 were conducted in accordance with the performance demonstration requirements of ASME Code,Section XI, Appendix VIII.
c) Further discuss whether additional welds could have been examined to augment the reduced volumetric coverage resulting from the limited examinations of the subject welds.
d) Please state whether any alternative examination such as full surface examination was performed on each of the ASME Code Class 1 and Class 2 piping welds. The staff notes that surface examination is not required for most of the damage mechanisms listed in Table 1 of ASME Code Case N-577 or N-578. Also, please state whether any indications were discovered as a result of surface examinations.
2.2 Request for Relief RR-G-05, Part A, ASME Code,Section XI, Examination Category B-D, Item B3.90, Full Penetration Welded Nozzles in Vessels Confirm that the UT examination methods used have been qualified in accordance with the performance demonstration requirements of ASME Section XI, Appendix VIII.
2.3 Request for Relief RR-G-5, Part B, ASME Code,Section XI, Examination Category B-F, Item B5.40, Pressure Retaining Dissimilar Metal Welds In Vessel Nozzles The coverage percentages provided in the licensees submittal appear to be only from the 45- and 60-degree UT scans performed on the welds. Please state whether any additional best effort coverage was obtained using the 35-, 42-, and 50-degree L-wave scans, as applicable.
2.4 Request for Relief RR-G-5, Part C, ASME Code,Section XI, Examination Category B-J, Items B9.11 and B9.31, Pressure Retaining Welds in Piping The licensees submittal states that the subject weld areas in ASME Code,Section XI, Category B-J, Item B9.31 were interrogated with a combination of 34-, 45- and 60-degree shear waves. The licensees submittal further states that examinations were performed as single-sided examinations from the pipe side of the welds.
4
Confirm the insonification angles and wave modalities used to examine each of the subject welds in ASME Code,Section XI, Category B-J, Item B9.31. If only shear wave techniques were used to examine the subject stainless steel welds, please explain why refracted longitudinal wave techniques were not used as part of a best effort examination. The L-wave method has been shown capable of detecting planar inside diameter (ID) surface-breaking flaws on the far-side of wrought stainless steel welds. Recent studies (Endnotes 2, 3, 4) recommend the use of both shear and L-waves to obtain the best detection results, with minimum false calls, in austenitic welds. If both shear and L-waves were used please state the best effort coverage achieved on the near- and far-side of the subject weld volumes.
2.5 Request for Relief RR-G-5, Part D, ASME Code,Section XI, Examination Category C-A, Items C1.10, C1.20, and C1.30, Pressure Retaining Welds in Class 2 Pressure Vessels State the materials of construction and the wall thickness for the pressure vessel welds submitted under ASME Code Category C-A.
2.6 Request for Relief RR-G-5, Part E, ASME Code,Section XI, Examination Category C-F-1, Items C5.13, C5.14, and C5.21, Pressure Retaining Welds in Austenitic Stainless Steel or High Alloy Piping On the area where the required ISI examination coverage was not achieved, state whether any indications were discovered as a result of ASME Code-required preservice (ASME Code,Section XI, Category C-F-1, Item C5.21) volumetric (e.g., radiography) and surface examinations that were performed on the ASME Code Class 2 piping welds.
State the wall thickness for the subject ASME Code Class 2 piping welds.
Provide volumetric coverage sketches detailing the insonification angles and coverage each angle provides on each weld.
The licensees submittal states that the subject weld areas were interrogated with a combination of 45-,
60-, and/or 70-degree shear waves. The licensees submittal further states that examinations were performed as single-sided examinations from the pipe side of the welds.
Confirm the insonification angles and wave modalities used to examine each of the subject welds. If only shear wave techniques were used to examine the subject stainless steel welds and the pipe thickness were greater than 0.50-inches, please explain why refracted longitudinal wave techniques where not used as part of a best effort examination. The L-wave method has been shown capable of detecting planar inside diameter (ID) surface-breaking flaws on the far-side of wrought stainless steel welds. Recent studies (Endnotes 1, 2, 3) recommend the use of both shear and L-waves to obtain the best detection results, with minimum false calls, in austenitic welds. If both shear and L-waves were used please state the best effort coverage achieved on the near- and far-side of the subject weld volumes.
2.7 Request for Relief RR-G-5, Part F, ASME Code,Section XI, Examination Category C-F-2, Item C5.51, Pressure Retaining Welds in Carbon or Low Alloy Steel Piping On the area where the required ISI examination coverage was not achieved, state whether any indications were discovered as a result of ASME Code-required preservice volumetric (e.g., radiography) and surface examinations that were performed on the carbon steel piping welds.
Endnotes
- 1. ASME Code Cases N-577-1 or N-578-1 are not approved for use in RG-1.147, Revision 16. Licensees base their RI-ISI inspection sample size and examination methodology on Table 1 of ASME Code Case N-577-1 or N-578-1.
5
- 2. F.V. Ammirato, X. Edelmann, and S.M. Walker, Examination of Dissimilar Metal Welds in BWR Nozzle-to-Safe End Joints, th 8 International Conference on NDE in the Nuclear Industry, ASM International, 1987.
- 3. P. Lemaitre, T.D. Koble, and S.R. Doctor, PISC III Capability Study on Wrought-to-Wrought Austenitic Steel Welds:
Evaluation at the Level of Procedures and Techniques, Effectiveness of Nondestructive Examination, Systems and Performance Demonstration, PVP-Volume 317, NDE-Volume 14, ASME, 1995.
- 4. M.T. Anderson, A.A. Diaz, A.D. Cinson, S.L. Crawford, S.E. Cumblidge, S.R Doctor, K.M. Denslow, and S. Ahmed, 2011. An Assessment of Ultrasonic Techniques for Far-Side Examinations of Austenitic Stainless Steel Piping Welds, NUREG/CR-7113, PNNL-19353, U. S. Nuclear Regulatory Commission, Washington, DC.
6
Hearing Identifier: NRR_PMDA Email Number: 311 Mail Envelope Properties (26E42474DB238C408C94990815A02F0968BB8EC2FD)
Subject:
FW: ME7378 - Kewaunee - Relief Req RR-G-5-1 to -40 Request for Additional Information (RAI)
Sent Date: 3/27/2012 3:17:03 PM Received Date: 3/27/2012 3:17:00 PM From: Feintuch, Karl Created By: Karl.Feintuch@nrc.gov Recipients:
"Rezai, Ali" <Ali.Rezai@nrc.gov>
Tracking Status: None "McLellan, Thomas" <Thomas.McLellan@nrc.gov>
Tracking Status: None
"'Jack Gadzala'" <jack.gadzala@dom.com>
Tracking Status: None
"'Craig D Sly'" <craig.d.sly@dom.com>
Tracking Status: None Post Office: HQCLSTR01.nrc.gov Files Size Date & Time MESSAGE 17409 3/27/2012 3:17:00 PM ME7378 TB RAI set EPNB McLellan, Rezai Re. 40 RRs 2012-03-27-1150 ET.docx 42090 Options Priority: Standard Return Notification: No Reply Requested: No Sensitivity: Normal Expiration Date:
Recipients Received:
DRAFT REQUEST FOR ADDITIONAL INFORMATION ON THE FOURTH TEN YEAR 10-YEAR INSERVICE INSPECTION INTERVAL REQUEST FOR RELIEF RR-G-05 DOMINION ENERGY KEWAUNEE, INC.
KEWAUNEE POWER STATION DOCKET NUMBER: 50-305 1.0 SCOPE By letter dated September 28, 2011, the licensee, Dominion Energy Kewaunee, Inc. (DEK),
submitted Request for Relief (RR) RR-G-05 from the requirements of the American Society of Mechanical Engineers (ASME) Boiler and Pressure Vessel Code,Section XI, Rules for Inservice Inspection of Nuclear Power Plant Components for Kewaunee Power Station (KPS).
The request for relief applies to the fourth 10-year inservice inspection (ISI) interval, in which the licensee adopted the 1998 Edition through the 2000 Addenda of ASME Code Section XI as the code of record.
In accordance with Title 10 of the Code of Federal Regulations (10 CFR) 50.55a(g)(5)(iii), the licensee has submitted the subject requests for relief for limited examinations in multiple ASME Code Examination Categories. The ASME Code requires that 100 percent of the examination volumes, or surface areas, described in ASME Code,Section XI, Tables IWB-2500 and IWC-2500 be performed during each interval. The licensee stated that 100 percent of the ASME Code-required volumes, or surface areas, are impractical to obtain at KPS.
10 CFR 50.55a(g)(5)(iii) states that when licensees determine that conformance with ASME Code requirements is impractical at their facility, they shall submit information to support this determination. The U.S. Nuclear Regulatory Commission (NRC) will evaluate such requests based on impracticality, and may impose alternatives, giving due consideration to public safety and the burden imposed on the licensee.
The NRC staff has reviewed the information submitted by the licensee, and based on this review, determined the following information is required to complete the evaluation. For clarity, the licensees requests have been evaluated according to ASME Code Examination Category and corresponding request for relief and have been labeled alphabetically.
The request for information (RAI) is structured into 7 items (RAII). Each item is assigned a tracking number in the format:
[TAC] - RAII - [Technical Branch] - [Primary Reviewer] - [Serial #] - [requested by year-month-day {nominally 30 days pending confirmation}]. For this request the assigned tracking numbers are listed in Section 2.0 below.
A clarification conference call is offered for any of the items. Some personnel attending for the NRC are in the Pacific Time Zone (PT). Therefore, phone calls are best held (Monday-Thursday afternoons ET) Please confirm the need for a clarification call any items by March 29, 2012, to facilitate scheduling of calls. These draft items become firm after clarification is confirmed by discussion prior to or at a clarification conference call.
2.0 REQUEST FOR ADDITIONAL INFORMATION (RAI)
The request consists of seven items:
ME7378-RAII-EPNB-McL-2.1-2012-04-27 ME7378-RAII-EPNB-McL-2.2-2012-04-27 ME7378-RAII-EPNB-McL-2.3-2012-04-27 ME7378-RAII-EPNB-McL-2.4-2012-04-27 ME7378-RAII-EPNB-McL-2.5-2012-04-27 ME7378-RAII-EPNB-McL-2.6-2012-04-27 ME7378-RAII-EPNB-McL-2.7-2012-04-27 In these tracking numbers:
EPNB = Piping and NDE Branch McL = Reviewers McLellan and , who is coordinating RAI traffic for TAC ME7378 2.n = 2.1 through 2.7 corresponding to the RAII shown in below.
2012-04-27 = April 27, 2012, which is subject to confirmation with DEK that referenced items (RAII) are clear for response.
In your response please associate this tracking number and the RAII that follow (items 2.1 to 2.7) with each of your answers.
2.1 General Information Required on Request for Relief RR-G-05 In Attachment 1 of the licensees submittal, DEK provided a general summary of the relief request. Under a section entitled ASME Code Requirements and the Basis for Relief, the licensee states the following:
Volumetric and surface examinations of welds and base material will be examined in accordance with the applicable [ASME Code,Section XI,]
Examination Category and Item Number and as required by the [KPS] Risk Informed Program.
During the performance of scheduled examinations, there were numerous instances where examiners reported some type of interference. DEK personnel evaluated every instance where this situation was reported, and when possible, alternative examination areas were selected to avoid having to examine restricted areas.
Piping welds that were selected that still necessitated limited examination (i.e.
less than or equal to 90% coverage) were those included in the KPS Fourth Ten-Year Inservice Inspection program to ensure examinations were performed on a representative sample of piping welds and piping welds that were not previously examined during the first 30 years of plant operation.
There are two risk informed program methodologies that are generally accepted for use by the NRC; they have been developed by the Electrical Power Research Institute (EPRI) and the Westinghouse Owners Group (WOG) and are documented in Topical Report TR-112657, Revised Risk-Informed Inservice Inspection Evaluation Procedure, Revision B-A, and Topical Report WCAP-14572, Westinghouse Owners Group Application of Risk-Informed Methods to Piping Inservice Inspection Topical Report,
Revision 1-NP-A, respectively. The two programs use either ASME Code Case N-578-1(Endnote 1), Risk-Informed Requirements for Class 1, 2 or 3 Piping, Method B Section XI, or Code Case N-577 (Endnote 1), Risk-Informed Requirements for Class 1, 2 or 3 Piping, Method A, both of which assign a new Examination Category R-A, listing welds, or other elements, according to expected forms of degradation.
The ASME Categories and Item numbers included in the licensees current request for relief appear to be for a conventional ISI program, not a risk-informed program.
However, as shown in the licensees statements above and in the data sheets provided for the specific welds listed under Category B-F, B-J, C-F-1, and C-F-2, the reviewer is lead to believe that these welds are part of a risk-informed program.
Please clarify the type, either conventional ISI program or a RI-ISI program, to which each of the welds submitted for relief are included. If a RI-ISI program is being implemented, provide a reference to the NRC Safety Evaluation (SE) approving this program and to which methodology (WOG or EPRI) was followed. If a RI-ISI program is not being implemented, state why alternative piping welds that have not been previously examined during the first 30 years of plant operation were selected for examination during the fourth interval.
Confirm the correct RI-ISI Examination Category and Item Numbers for each of the welds listed in Table 2.1.1 below. Specifically, if a RI-ISI program is being implemented, please list the RI-ISI R-A Item Numbers in accordance with the appropriate ASME Code Case or if KPS has an unique identifying RI-ISI system based on either RI-ISI ASME Code Case clarify how to identify the welds examined.
Table 2.1.1 - Class 1 and 2 Piping Welds ASME Code Weld ID Weld Type Category Item B-F B5.40 PR-W1DM PZR 6 Nozzle-to-Safe End B-F B5.40 PR-W26DM PZR 6 Nozzle-to-Safe End B-F B5.40 RC-W67DM PZR 14 Nozzle-to-Safe End B-J B9.11 PR-W27 6 PZR Relief Circumferential Weld B-J B9.11 RC-W60 6 Reactor Coolant Circumferential Weld B-J B9.11 SI-W51 6 Safety Injection Circumferential Weld B-J B9.11 RHR-W9 8 Residual Heat Removal Circumferential Weld B-J B9.11 SI-W74 12 Safety Injection Circumferential Weld B-J B9.31 RC-W3BC 8 Reactor Coolant Pipe Branch Connection B-J B9.31 RC-W22BC 6 Reactor Coolant Pipe Branch Connection C-F-1 C5.13 ICS-W180 6 Containment Spray Circumferential Weld C-F-1 C5.13 ICS-W181 6 Containment Spray Circumferential Weld C-F-1 C5.13 RHR-W419 6 Residual Heat Removal Circumferential Weld C-F-1 C5.13 ICS-W45 8 Containment Spray Circumferential Weld
Table 2.1.1 - Class 1 and 2 Piping Welds ASME Code Weld ID Weld Type Category Item C-F-1 C5.14 SI-W429 6 Safety Injection Circumferential Weld C-F-1 C5.21 SI-W249 3 Safety Injection circumferential Weld C-F-1 C5.21 AFW-W148 3 Auxiliary Feedwater Circumferential Weld C-F-1 C5.21 AFW-W151 3 Auxiliary Feedwater Circumferential Weld C-F-1 C5.21 AFW-W152 3 Auxiliary Feedwater Circumferential Weld C-F-1 C5.21 AFW-W155 3 Auxiliary Feedwater Circumferential Weld C-F-2 C5.61 AFW-W156 3 Auxiliary Feedwater Circumferential Weld C-F-2 C5.61 AFW-W171 3 Auxiliary Feedwater Circumferential Weld C-F-2 C5.61 AFW-W172 3 Auxiliary Feedwater Circumferential Weld C-F-2 C5.61 AFW-W178 3 Auxiliary Feedwater Circumferential Weld C-F-2 C5.61 AFW-W189 3 Auxiliary Feedwater Circumferential Weld C-F-2 C5.61 AFW-W190 3 Auxiliary Feedwater Circumferential Weld C-F-2 C5.61 AFW-W191 3 Auxiliary Feedwater Circumferential Weld C-F-2 C5.61 AFW-W192 3 Auxiliary Feedwater Circumferential Weld C-F-2 C5.61 AFW-W194 3 Auxiliary Feedwater Circumferential Weld C-F-2 C5.61 AFW-W195 3 Auxiliary Feedwater Circumferential Weld C-F-2 C5.61 AFW-W196 3 Auxiliary Feedwater Circumferential Weld C-F-2 C5.61 AFW-W197 3 Auxiliary Feedwater Circumferential Weld C-F-2 C5.61 AFW-W198 3 Auxiliary Feedwater Circumferential Weld In addition, if the welds listed in Table 2.1.1 above were examined under a RI-ISI program:
a) Please state the total number of Class 1 and Class 2 piping welds included in the overall risk-informed program so that the 33 limited examinations can be assessed within the scope of all examinations being implemented.
b) Please confirm whether the ultrasonic (UT) examination methods for all piping welds listed in Table 2.1.1 were conducted in accordance with the performance demonstration requirements of ASME Code,Section XI, Appendix VIII.
c) Further discuss whether additional welds could have been examined to augment the reduced volumetric coverage resulting from the limited examinations of the subject welds.
d) Please state whether any alternative examination such as full surface examination was performed on each of the ASME Code Class 1 and Class 2 piping welds. The staff notes that surface examination is not required for most of the damage mechanisms listed in Table 1 of ASME Code Case N-577 or N-578. Also, please state whether any indications were discovered as a result of surface examinations.
2.2 Request for Relief RR-G-05, Part A, ASME Code,Section XI, Examination Category B-D, Item B3.90, Full Penetration Welded Nozzles in Vessels Confirm that the UT examination methods used have been qualified in accordance with the performance demonstration requirements of ASME Section XI, Appendix VIII.
2.3 Request for Relief RR-G-5, Part B, ASME Code,Section XI, Examination Category B-F, Item B5.40, Pressure Retaining Dissimilar Metal Welds In Vessel Nozzles The coverage percentages provided in the licensees submittal appear to be only from the 45- and 60-degree UT scans performed on the welds. Please state whether any additional best effort coverage was obtained using the 35-, 42-, and 50-degree L-wave scans, as applicable.
2.4 Request for Relief RR-G-5, Part C, ASME Code,Section XI, Examination Category B-J, Items B9.11 and B9.31, Pressure Retaining Welds in Piping The licensees submittal states that the subject weld areas in ASME Code,Section XI, Category B-J, Item B9.31 were interrogated with a combination of 34-, 45- and 60-degree shear waves. The licensees submittal further states that examinations were performed as single-sided examinations from the pipe side of the welds.
Confirm the insonification angles and wave modalities used to examine each of the subject welds in ASME Code,Section XI, Category B-J, Item B9.31. If only shear wave techniques were used to examine the subject stainless steel welds, please explain why refracted longitudinal wave techniques were not used as part of a best effort examination. The L-wave method has been shown capable of detecting planar inside diameter (ID) surface-breaking flaws on the far-side of wrought stainless steel welds.
Recent studies (Endnotes 2, 3, 4) recommend the use of both shear and L-waves to obtain the best detection results, with minimum false calls, in austenitic welds. If both shear and L-waves were used please state the best effort coverage achieved on the near- and far-side of the subject weld volumes.
2.5 Request for Relief RR-G-5, Part D, ASME Code,Section XI, Examination Category C-A, Items C1.10, C1.20, and C1.30, Pressure Retaining Welds in Class 2 Pressure Vessels State the materials of construction and the wall thickness for the pressure vessel welds submitted under ASME Code Category C-A.
2.6 Request for Relief RR-G-5, Part E, ASME Code,Section XI, Examination Category C-F-1, Items C5.13, C5.14, and C5.21, Pressure Retaining Welds in Austenitic Stainless Steel or High Alloy Piping On the area where the required ISI examination coverage was not achieved, state whether any indications were discovered as a result of ASME Code-required preservice (ASME Code,Section XI, Category C-F-1, Item C5.21) volumetric (e.g., radiography) and surface examinations that were performed on the ASME Code Class 2 piping welds.
State the wall thickness for the subject ASME Code Class 2 piping welds.
Provide volumetric coverage sketches detailing the insonification angles and coverage each angle provides on each weld.
The licensees submittal states that the subject weld areas were interrogated with a combination of 45-, 60-, and/or 70-degree shear waves. The licensees submittal further states that examinations were performed as single-sided examinations from the pipe side of the welds.
Confirm the insonification angles and wave modalities used to examine each of the subject welds. If only shear wave techniques were used to examine the subject stainless steel welds and the pipe thickness were greater than 0.50-inches, please explain why refracted longitudinal wave techniques where not used as part of a best effort examination. The L-wave method has been shown capable of detecting planar inside diameter (ID) surface-breaking flaws on the far-side of wrought stainless steel welds. Recent studies (Endnotes 1, 2, 3) recommend the use of both shear and L-waves to obtain the best detection results, with minimum false calls, in austenitic welds.
If both shear and L-waves were used please state the best effort coverage achieved on the near- and far-side of the subject weld volumes.
2.7 Request for Relief RR-G-5, Part F, ASME Code,Section XI, Examination Category C-F-2, Item C5.51, Pressure Retaining Welds in Carbon or Low Alloy Steel Piping On the area where the required ISI examination coverage was not achieved, state whether any indications were discovered as a result of ASME Code-required preservice volumetric (e.g., radiography) and surface examinations that were performed on the carbon steel piping welds.
Endnotes
- 1. ASME Code Cases N-577-1 or N-578-1 are not approved for use in RG-1.147, Revision 16. Licensees base their RI-ISI inspection sample size and examination methodology on Table 1 of ASME Code Case N-577-1 or N-578-1.
- 2. F.V. Ammirato, X. Edelmann, and S.M. Walker, Examination of Dissimilar Metal Welds in BWR Nozzle-to-th Safe End Joints, 8 International Conference on NDE in the Nuclear Industry, ASM International, 1987.
- 3. P. Lemaitre, T.D. Koble, and S.R. Doctor, PISC III Capability Study on Wrought-to-Wrought Austenitic Steel Welds: Evaluation at the Level of Procedures and Techniques, Effectiveness of Nondestructive Examination, Systems and Performance Demonstration, PVP-Volume 317, NDE-Volume 14, ASME, 1995.
- 4. M.T. Anderson, A.A. Diaz, A.D. Cinson, S.L. Crawford, S.E. Cumblidge, S.R Doctor, K.M. Denslow, and S.
Ahmed, 2011. An Assessment of Ultrasonic Techniques for Far-Side Examinations of Austenitic Stainless Steel Piping Welds, NUREG/CR-7113, PNNL-19353, U. S. Nuclear Regulatory Commission, Washington, DC.