ML15317A158
| ML15317A158 | |
| Person / Time | |
|---|---|
| Site: | Comanche Peak  |
| Issue date: | 11/13/2015 |
| From: | Balwant Singal Plant Licensing Branch IV |
| To: | Hope T Luminant Generation Co |
| Singal B | |
| References | |
| CAC MF6557, CAC MF6558, CAC MF6559 | |
| Download: ML15317A158 (4) | |
Text
1 Burkhardt, Janet From:
Singal, Balwant Sent:
Friday, November 13, 2015 8:36 AM To:
'Hope, Timothy' (Timothy.Hope@luminant.com)
Cc:
'Jack.Hicks@luminant.com' (Jack.Hicks@luminant.com); Burkhardt, Janet
Subject:
Request for Additional Information (RAI) - Relief Requets B-15, C-2, and C-4 (CAC Nos.
MF6557, MF6558, and MF6559)
Attachments:
RAI-MF6557-RR-B15.docx
- Tim, By letters dated August 03, 2015 (Agencywide Documents Access and Management System (ADAMS)
Accession Numbers ML15224B365, ML15224B366, and ML15224B367), Luminant Generation Company LLC (the licensee), submitted Relief Requests (RRs) B-15, C-2, and C-4 to the U.S. Nuclear Regulatory Commission (NRC) for the second ten-year inservice inspection (ISI) interval of Comanche Peak Nuclear Power Plant, Unit 2. In RRs B-15, C-2, and C-4, the licensee requested relief from the examination requirements of the American Society of Mechanical Engineers Boiler and Pressure Vessel Code,Section XI, applicable to welds in the reactor pressure vessel, containment spray heat exchanger shell, and residual heat removal heat exchanger shell.
The NRC staff requests for the attached additional information to complete the review of these RRs.
Draft RAI were transmitted on November 6, 2015. Jack Hicks of your organization informed the NRC staff on November 12, 2015 that a clarification call is not needed.
Please treat this e-mail as formal transmittal of RAIs. You are requested to respond to this RAI request within 30 days from the date of this e-mail.
Thanks.
REQUEST FOR ADDITIONAL INFORMATION RELIEF REQUESTS B-15, C-2, AND C-4 COMANCHE PEAK NUCLEAR POWER PLANT, UNIT 2 LUMINANT GENERATION COMPANY LLC DOCKET NUMBER 50-446 By letters dated August 03, 2015 (Agencywide Documents Access and Management System (ADAMS) Accession Numbers ML15224B365, ML15224B366, and ML15224B367), Luminant Generation Company LLC (the licensee), submitted Relief Requests (RRs) B-15, C-2, and C-4 to the U.S. Nuclear Regulatory Commission (NRC) for the second ten-year inservice inspection (ISI) interval of Comanche Peak Nuclear Power Plant, Unit 2. In RRs B-15, C-2, and C-4, the licensee requested relief from the examination requirements of the American Society of Mechanical Engineers Boiler and Pressure Vessel Code (ASME Code),Section XI, applicable to welds in the reactor pressure vessel, containment spray heat exchanger shell, and residual heat removal heat exchanger shell. The licensee has determined that conformance with the examination requirementsSection XI of the ASME Code for these welds is impractical. Title 10 of the Code of Federal Regulations (10 CFR), Paragraph 50.55a(g)(5)(iii) requires the licensee to submit information to the NRC to support the determination of impracticality.
The NRC staff requests for the following additional information to complete the review of RRs B-15, C-2, and C-4.
REQUEST FOR ADDITIONAL INFORMATION (RAI)
RAI 1
In relief request B-15, the staff notes that weld TCX-1-1300-2 is in Examination Category B-A, Item No. B1.21 of Table IWB-2500-1, Examination Categories, of the ASME Code,Section XI. As indicated in Table IWB-2500-1, the examination requirement for Item No. B1.21 welds is essentially 100% of the accessible weld length. The ASME Code Committees recognize the limitations of examining these welds and specifically stated in this particular ASME Code requirement to examine the accessible length of the welds. Please clarify whether or not that essentially 100% of the accessible weld length was achieved for weld TCX-1-1300-2.
RAI 2
Please provide the following additional information regarding the examination diagrams of the subject RRs:
a) Depending on the licensees response to RAI 1 regarding RR B-15, with respect to weld TCX-1-1300-2, provide the following information: (1) the ASME Code,Section XI required examination volume (cross sectional area multiplied by weld length), (2) the scan angles used for the examination, and (3) the achieved scanned volumes (cross sectional area multiplied by weld length) for both the axial and circumferential scan directions. Please refer to the presentation slides for, Industry/NRC NDE [Non Destructive Examination] Technical Information Exchange Public Meeting, January 13 -15, 2015, (ADAMS Accession Number ML15013A266) for a discussion of the staffs expectations for the content of an examination/inspection diagram (see slide 12 for an example). The sketch/diagram should show relevant dimensions, such as wall thickness and weld dimensions.
b) Regarding RR C-2, with respect to weld TCX-2-1180-1-2, provide the following information:
(1) the ASME Code,Section XI required examination volume (cross sectional area multiplied by weld length), (2) the scan angles used for the examination, (3) the achieved scanned volumes for both the axial and circumferential scan directions (cross sectional area multiplied by weld length), and (4) the material of construction of weld TCX-2-1180-1-2 and the base metal immediately adjacent to the weld. Please refer to the presentation slides for, Industry/NRC NDE Technical Information Exchange Public Meeting, January 13 -15, 2015, for a discussion of the staffs expectations for the content of an examination/inspection diagram (see slide 12 for an example). The sketch/diagram should show relevant dimensions, such as wall thickness and weld dimensions.
c) Regarding RR C-4, with respect to the subject welds, provide the following information: (1) the ASME Code,Section XI required examination volume (cross sectional area multiplied by weld length), (2) the scan angles used for the examination, (3) the achieved scanned volumes for both the axial and circumferential scan directions (cross sectional area multiplied by weld length), and (4) the material of construction of the subject welds and the base metal immediately adjacent to the welds. Please refer to the presentation slides for, Industry/NRC NDE Technical Information Exchange Public Meeting, January 13 -15, 2015, for a discussion of the staffs expectations for the content of an examination/inspection diagram (see slide 12 for an example). The sketch/diagram should show relevant dimensions, such as wall thickness and weld dimensions.
RAI 3
For the examinations performed in RRs B-15, C-2, and C-4, please discuss the adequacy of one-sided exams, if applicable. Please discuss, for example, whether 50% or 100% credit is given to the achieved one-sided examination volume. If 100% credit is given, please provide the justification.
RAI 4
Please provide the following information regarding the ultrasonic examination procedures used in the subject RRs:
a) Depending on the licensees response to RAI 1 regarding RR B-15, please discuss the ASME Code Section XI, Appendix I requirement from which procedure TXI-ISI-306 is based. If supplements apply, please discuss which supplements were used.
b) With respect to RRs C-2 and C-4, please discuss the ASME Code Section XI, Appendix I requirement from which procedure TXI-ISI-214 is based. If supplements apply, please discuss which supplements were used.
RAI 5
For the examinations performed in RRs B-15 (if applicable), C-2, and C-4, please discuss other means attempted, if any, to achieve the ASME Code-required volume.
RAI 6
Please discuss any plant-specific operating experience regarding potential degradation in the subject welds in RRs C-2 and C-4, such as stress corrosion cracking or general corrosion.