ML12021A009
| ML12021A009 | |
| Person / Time | |
|---|---|
| Site: | Davis Besse  |
| Issue date: | 01/13/2012 |
| From: | - No Known Affiliation |
| To: | Division of License Renewal |
| References | |
| Download: ML12021A009 (12) | |
Text
Davis-BesseNPEm Resource From: dorts@firstenergycorp.com Sent: Friday, January 13, 2012 9:55 AM To: CuadradoDeJesus, Samuel Cc: custerc@firstenergycorp.com
Subject:
FENOC Letter L-12-001 Signed and Mailed Attachments: L-12-001 RAI 3.1.2.2.16-3 SG T-TS Welds_2012-01-13.pdf Sam..... FENOC Letter L-12-001, which contains the FENOC response to Davis-Besse License Renewal NRC RAI 3.1.2.2.16-3, was signed and placed in the mail today. Attached is an electronic copy for your use.
Should you have questions regarding the attached, please contact Cliff Custer or me.
Thank you, Steve Dort DBNPS License Renewal
The information contained in this message is intended only for the personal and confidential use of the recipient(s) named above. If the reader of this message is not the intended recipient or an agent responsible for delivering it to the intended recipient, you are hereby notified that you have received this document in error and that any review, dissemination, distribution, or copying of this message is strictly prohibited. If you have received this communication in error, please notify us immediately, and delete the original message.
1
Hearing Identifier: Davis_BesseLicenseRenewal_Saf_NonPublic Email Number: 3191 Mail Envelope Properties (OF4C8C8948.FB699770-ON85257984.0051924D-85257984.0051E9A2)
Subject:
FENOC Letter L-12-001 Signed and Mailed Sent Date: 1/13/2012 9:54:41 AM Received Date: 1/13/2012 9:54:47 AM From: dorts@firstenergycorp.com Created By: dorts@firstenergycorp.com Recipients:
"custerc@firstenergycorp.com" <custerc@firstenergycorp.com>
Tracking Status: None "CuadradoDeJesus, Samuel" <Samuel.CuadradoDeJesus@nrc.gov>
Tracking Status: None Post Office: FirstEnergyCorp.com Files Size Date & Time MESSAGE 940 1/13/2012 9:54:47 AM L-12-001 RAI 3.1.2.2.16-3 SG T-TS Welds_2012-01-13.pdf 54744 Options Priority: Standard Return Notification: No Reply Requested: No Sensitivity: Normal Expiration Date:
Recipients Received:
Attachment L-12-001 Reply to Request for Additional Information for the Review of the Davis-Besse Nuclear Power Station, Unit No. 1 (DBNPS), License Renewal Application, Section 3.1.2.2 Page 1 of 2 Section 3.1.2.2 Question RAI 3.1.2.2.16-3
Background
By letter dated November 23, 2011, the applicant responded to RAI 3.1.2.2.16-2, which addresses the extent and method of the inspections to manage cracking due to primary water stress corrosion cracking (PWSCC) of the steam generator (SG) tube-to-tubesheet welds. In its response, the applicant indicated that a gross visual inspection coupled with eddy-current inspections will be performed on the SG tube-to-tubesheet welds. The applicant also indicated that the inspection schedule will be concurrent with the eddy-current inspections of the SG tubes in accordance with Davis-Besse Technical Specification 5.5.8, Steam Generator (SG) Program.
The applicant further indicated that at a minimum, 100% of the tubes are inspected at sequential periods of 60 effective full power months.
Issue In its review, the staff noted that it is not clear whether the gross visual inspection of the tube-to-tubesheet welds will include the welds on the hot leg, cold leg, or both legs. The staff also needs more clarifications on the extent and method of the visual inspection addressed in the applicant's response.
Request
- 1. Clarify whether the visual inspection will be conducted on the welds on the hot leg, cold leg, or both legs. In addition, describe the extent of the visual inspection (i.e., what percentage of the welds will be inspected),
and clarify whether the visual inspection will be conducted on each tube-to-tubesheet weld.
- 2. Provide information on the objective, equipment, and method of the visual inspections.
Attachment L-12-001 Page 2 of 2 RESPONSE RAI 3.1.2.2.16-3
- 1. The extent of the gross visual inspection will be 100% of the steam generator tube-to-tubesheet welds (includes both the hot leg and cold leg welds). Gross visual inspection of the tube-to-tubesheet welds will be scheduled concurrent with eddy-current inspection of the steam generator tubes that are scheduled in accordance with Davis-Besse Technical Specification 5.5.8. At a minimum, 100%
of the tubes are inspected at sequential periods of 60 effective full power months, and therefore, at a minimum, 100% of the tube-to-tubesheet welds (includes both the hot leg and cold leg welds) will be inspected at sequential periods of 60 effective full power months.
- 2. The gross visual inspection of the tube-to-tubesheet welds will consist of a remote-visual examination using a manipulator camera to obtain a straight-on view of the weld with a visual acuity sufficient to detect evidence of degradation. The gross visual inspections will be performed by personnel who are qualified for American Society of Mechanical Engineers (ASME) code visual examination (i.e., are certified VT-1 or VT-3 examiners) and are knowledgeable in the type of tube-to-tubesheet welds being examined (i.e., fillet welds).
LRA Sections A.1.38 and B.2.38, both titled Steam Generator Tube Integrity Program, and LRA Table A-1, Davis-Besse License Renewal Commitments, license renewal future Commitment number 25, are revised consistent with this response.
See the Enclosure to this letter for the revision to the DBNPS LRA.
Enclosure Davis-Besse Nuclear Power Station, Unit No. 1 (DBNPS)
Letter L-12-001 Amendment No. 23 to the DBNPS License Renewal Application Page 1 of 6 License Renewal Application Sections Affected Section A.1.38 Table A-1 Section B.2.38 The Enclosure identifies the change to the License Renewal Application (LRA) by Affected LRA Section, LRA Page No., and Affected Paragraph and Sentence. The count for the affected paragraph, sentence, bullet, etc. starts at the beginning of the affected Section or at the top of the affected page, as appropriate. Below each section the reason for the change is identified, and the sentence affected is printed in italics with deleted text lined-out and added text underlined.
Enclosure L-12-001 Page 2 of 6 Affected LRA Section LRA Page No. Affected Paragraph and Sentence A.1.38 Pages A-24 & 3rd Paragraph A-25 In response to RAI 3.1.2.2.16-3, the third paragraph of LRA Section A.1.38, Steam Generator Tube Integrity Program, previously revised in response to RAI 3.1.2.2.16-2 by FENOC letter dated November 23, 2011 (ML11335A223), is replaced in its entirety to read as follows:
In addition, cracking due to PWSCC is managed for the steam generator tube-to-tubesheet welds (Alloy 600) by a combination of the PWR Water Chemistry Program and the Steam Generator Tube Integrity Program. The PWR Water Chemistry Program controls peak levels of various contaminants (e.g.,
dissolved oxygen, chlorides, fluorides, and sulfates) below the system-specific limits that can accelerate cracking for nickel-alloy components. The Steam Generator Tube Integrity Program includes gross visual inspection of the steam generator tube-to-tubesheet welds coupled with eddy-current inspection (i.e.,
bobbin coil or rotating coil examinations) of the tubes to monitor for cracking and degradation of the tube-to-tubesheet welds (Alloy 600). The gross visual inspection of the tube-to-tubesheet welds are scheduled concurrent with eddy-current inspection of the steam generator tubes that are scheduled in accordance with Davis-Besse Technical Specification 5.5.8. At a minimum, 100%
of the tubes are inspected at sequential periods of 60 effective full power months, and therefore, at a minimum, 100% of the tube-to-tubesheet welds (includes both the hot leg and cold leg welds) are inspected at sequential periods of 60 effective full power months. The gross visual inspection of the tube-to-tubesheet welds consists of a remote-visual examination using a manipulator camera to obtain a straight-on view of the weld with a visual acuity sufficient to detect evidence of degradation. The gross visual examinations are performed by personnel who are qualified for American Society of Mechanical Engineers (ASME) code visual examination (i.e., are certified VT-1 or VT-3 examiners) and are knowledgeable in the type of tube-to-tubesheet welds being examined (i.e., fillet welds).
Acceptance criteria for the gross visual inspections and the eddy-current inspections consist of no indication of cracking or relevant conditions of degradation. Should the steam generators be replaced in the future with a design such that the tubes, tubesheet cladding and tube-to-tubesheet welds are fabricated of Alloy 690 material, only the PWR Water Chemistry Program will manage cracking due to PWSCC of the tube-to-tubesheet welds and the gross visual inspection will no longer be required.
Enclosure L-12-001 Page 3 of 6 Affected LRA Section LRA Page No. Affected Paragraph and Sentence Table A-1 Page A-69 Commitment No. 25 In response to RAI 3.1.2.2.16-3, LRA Table A-1, Davis-Besse License Renewal Commitments, license renewal future Commitment No. 25, previously revised in response to RAI 3.1.2.2.16-2 by FENOC letter dated November 23, 2011 (ML11335A223), is replaced in its entirety to read as follows:
Table A-1 Davis-Besse License Renewal Commitments Related LRA Item Implementation Commitment Source Section No./
Number Schedule Comments 25 Enhance the Steam Generator Tube Integrity Program to: Prior to LRA A.1.38 April 22, 2017 x Include gross visual inspection of the steam generator and B.2.38 tube-to-tubesheet welds coupled with eddy-current inspection FENOC Response to (i.e., bobbin coil or rotating coil examinations) of the tubes to Letter NRC RAI monitor for cracking and degradation of the tube-to-tubesheet L-12-001 3.1.2.2.16-3 welds (Alloy 600). Schedule the gross visual inspection of the from tube-to-tubesheet welds concurrent with eddy-current inspection NRC Letter of the steam generator tubes that are scheduled in accordance dated with Davis-Besse Technical Specification 5.5.8 such that 100% December 27, of the tube-to-tubesheet welds (includes both the hot leg and 2011 cold leg welds) are inspected at sequential periods of 60 effective full power months. Perform the gross visual inspection of the tube-to-tubesheet welds through remote-visual examination using a manipulator camera to obtain a straight-on
Enclosure L-12-001 Page 4 of 6 Table A-1 Davis-Besse License Renewal Commitments Related LRA Item Implementation Commitment Source Section No./
Number Schedule Comments view of the weld with a visual acuity sufficient to detect evidence of degradation. Perform the gross visual inspections using personnel who are qualified for American Society of Mechanical Engineers (ASME) code visual examination (i.e., are certified VT-1 or VT-3 examiners) and are knowledgeable in the type of tube-to-tubesheet welds being examined (i.e., fillet welds).
Define the acceptance criteria for the gross visual inspections and the eddy-current inspections as no indication of cracking or relevant conditions of degradation.
Enclosure L-12-001 Page 5 of 6 Affected LRA Section LRA Page No. Affected Paragraph and Sentence B.2.38 Page B-151 Program Description subsection, 4th paragraph; and, Enhancements subsection In response to RAI 3.1.2.2.16-3, LRA Section B.2.38, Steam Generator Tube Integrity Program, the fourth paragraph of subsection Program Description and the Enhancements subsection, previously added in response to RAI 3.1.2.2.16-2 by FENOC letter dated November 23, 2011 (ML11335A223), are replaced in their entirety to read as follows:
[Program Description, 4th paragraph]
In addition, cracking due to PWSCC will be managed for the steam generator tube-to-tubesheet welds (Alloy 600) by a combination of the PWR Water Chemistry Program and the Steam Generator Tube Integrity Program. The PWR Water Chemistry Program controls peak levels of various contaminants (e.g.,
dissolved oxygen, chlorides, fluorides, and sulfates) below the system-specific limits that can accelerate cracking for nickel-alloy components. The Steam Generator Tube Integrity Program will include gross visual inspection of the steam generator tube-to-tubesheet welds coupled with eddy-current inspection (i.e., bobbin coil or rotating coil examinations) of the tubes to monitor for cracking and degradation of the tube-to-tubesheet welds (Alloy 600). The gross visual inspection of the tube-to-tubesheet welds will be scheduled concurrent with eddy-current inspection of the steam generator tubes that are scheduled in accordance with Davis-Besse Technical Specification 5.5.8. At a minimum, 100%
of the tubes are inspected at sequential periods of 60 effective full power months and therefore, at a minimum, 100% of the tube-to-tubesheet welds (includes both the hot leg and cold leg welds) will be inspected at sequential periods of 60 effective full power months. The gross visual inspection of the tube-to-tubesheet welds will consist of a remote-visual examination using a manipulator camera to obtain a straight-on view of the weld with a visual acuity sufficient to detect evidence of degradation. The gross visual inspections will be performed by personnel who are qualified for American Society of Mechanical Engineers (ASME) code visual examination (i.e., are certified VT-1 or VT-3 examiners) and are knowledgeable in the type of tube-to-tubesheet welds being examined (i.e., fillet welds). Acceptance criteria for the gross visual inspections and the eddy-current inspections will consist of no indication of cracking or relevant conditions of degradation. Should the steam generators be replaced in the future with a design such that the tubes, tubesheet cladding and tube-to-tubesheet welds are fabricated of Alloy 690 material, only the PWR Water Chemistry Program will manage cracking due to PWSCC of the
Enclosure L-12-001 Page 6 of 6 tube-to-tubesheet welds and the gross visual inspection will no longer be required.
Enhancements The following enhancement will be implemented in the identified program elements prior to the period of extended operation.
x Scope, Parameters Monitored or Inspected, Detection of Aging Effects, Acceptance Criteria The Steam Generator Tube Integrity Program will include gross visual inspection of the steam generator tube-to-tubesheet welds coupled with eddy-current inspection (i.e., bobbin coil or rotating coil examinations) of the tubes to monitor for cracking and degradation of the tube-to-tubesheet welds (Alloy 600). The gross visual inspection of the tube-to-tubesheet welds will be scheduled concurrent with eddy-current inspection of the steam generator tubes that are scheduled in accordance with Davis-Besse Technical Specification 5.5.8. At a minimum, 100% of the tubes are inspected at sequential periods of 60 effective full power months and therefore, at a minimum, 100% of the tube-to-tubesheet welds (includes both the hot leg and cold leg welds) will be inspected at sequential periods of 60 effective full power months. The gross visual inspection of the tube-to-tubesheet welds will consist of a remote-visual examination using a manipulator camera to obtain a straight-on view of the weld with a visual acuity sufficient to detect evidence of degradation. The gross visual inspections will be performed by personnel who are qualified for American Society of Mechanical Engineers (ASME) code visual examination (i.e.,
are certified VT-1 or VT-3 examiners) and are knowledgeable in the type of tube-to-tubesheet welds being examined (i.e., fillet welds). Acceptance criteria for the gross visual inspections and the eddy-current inspections will consist of no indication of cracking or relevant conditions of degradation. Should the steam generators be replaced in the future with a design such that the tubes, tubesheet cladding and tube-to-tubesheet welds are fabricated of Alloy 690 material, only the PWR Water Chemistry Program will manage cracking due to PWSCC of the tube-to-tubesheet welds and the gross visual inspection will no longer be required.