ML14065A094
| ML14065A094 | |
| Person / Time | |
|---|---|
| Site: | Palisades  |
| Issue date: | 03/05/2014 |
| From: | Mahesh Chawla Division of Operating Reactor Licensing |
| To: | Erickson J Entergy Nuclear Operations |
| References | |
| MF3508 | |
| Download: ML14065A094 (5) | |
Text
NRR-PMDAPEm Resource From: Chawla, Mahesh Sent: Wednesday, March 05, 2014 5:29 PM To: ERICKSON, JEFFREY S (JERICKS@entergy.com); MIKSA, JAMES P (jmiksa@entergy.com); GUSTAFSON, OTTO W (ogustaf@entergy.com); DOTSON, BARBARA E (bdotson@entergy.com)
Cc: Garmoe, Alex; Taylor, Thomas; Duncan, Eric; Scarbeary, April; Shah, Swetha; Collins, Jay; Carlson, Robert; Lupold, Timothy; Cumblidge, Stephen
Subject:
Request for Additional Information (3rd set) - RR 4 Proposed Alternative, Use of Alternate ASME Code Case N-770-1 Baseline Examination - MF3508 Attachments: Palisades N-770-1 MF3508 3RD RAI.docx By letter dated February 25, 2014 Entergy Nuclear Operations, Inc. (the licensee), proposed an alternative to 10 CFR 50.55a(g)(6)(ii)(F)(3) for Palisades Nuclear Plant (Palisades). This regulation defines the inspection requirement for branch connection butt welds at Palisades in accordance with American Society of Mechanical Engineers Boiler and Pressure Vessel Code Case N-770-1, Alternative Examination Requirements and Acceptance Standards for Class 1 PWR Piping and Vessel Nozzle Butt Welds Fabricated With UNS N06082 or UNS W86182 Weld Filler Material With or Without Application of Listed Mitigation Activities, with NRC conditions. The licensee is requesting an extension of the required inspection for at least one cycle of operation.
The NRC staff has determined the need for additional information. This is the 3rd set of RAIs on this request.
Please arrange a teleconference with the NRC staff when you are ready to provide the requested information.
Thanks Mahesh Chawla Project Manager Phone: 301-415-8371 Fax: 301-415-1222 mahesh.chawla@nrc.gov 1
Hearing Identifier: NRR_PMDA Email Number: 1145 Mail Envelope Properties (Mahesh.Chawla@nrc.gov20140305172800)
Subject:
Request for Additional Information (3rd set) - RR 4 Proposed Alternative, Use of Alternate ASME Code Case N-770-1 Baseline Examination - MF3508 Sent Date: 3/5/2014 5:28:38 PM Received Date: 3/5/2014 5:28:00 PM From: Chawla, Mahesh Created By: Mahesh.Chawla@nrc.gov Recipients:
"Garmoe, Alex" <Alex.Garmoe@nrc.gov>
Tracking Status: None "Taylor, Thomas" <Thomas.Taylor@nrc.gov>
Tracking Status: None "Duncan, Eric" <Eric.Duncan@nrc.gov>
Tracking Status: None "Scarbeary, April" <April.Scarbeary@nrc.gov>
Tracking Status: None "Shah, Swetha" <Swetha.Shah@nrc.gov>
Tracking Status: None "Collins, Jay" <Jay.Collins@nrc.gov>
Tracking Status: None "Carlson, Robert" <Robert.Carlson@nrc.gov>
Tracking Status: None "Lupold, Timothy" <Timothy.Lupold@nrc.gov>
Tracking Status: None "Cumblidge, Stephen" <Stephen.Cumblidge@nrc.gov>
Tracking Status: None "ERICKSON, JEFFREY S (JERICKS@entergy.com)" <JERICKS@entergy.com>
Tracking Status: None "MIKSA, JAMES P (jmiksa@entergy.com)" <jmiksa@entergy.com>
Tracking Status: None "GUSTAFSON, OTTO W (ogustaf@entergy.com)" <ogustaf@entergy.com>
Tracking Status: None "DOTSON, BARBARA E (bdotson@entergy.com)" <bdotson@entergy.com>
Tracking Status: None Post Office:
Files Size Date & Time MESSAGE 1110 3/5/2014 5:28:00 PM Palisades N-770-1 MF3508 3RD RAI.docx 28777 Options Priority: Standard Return Notification: No Reply Requested: No Sensitivity: Normal Expiration Date:
Recipients Received:
REQUEST FOR ADDITIONAL INFORMATION REQUEST FOR RELIEF FROM 10 CFR 50.55a(g)(6)(ii)(F)(3) REQUIREMENTS FOR EXAMINATION OF BRANCH CONNECTION BUTT WELDS ENTERGY NUCLEAR OPTERATIONS INC.,
PALISADES NUCLEAR PLANT DOCKET NO. 50-255 By letter dated February 25, 2014 Entergy Nuclear Operations, Inc. (the licensee), proposed an alternative to 10 CFR 50.55a(g)(6)(ii)(F)(3) for Palisades Nuclear Plant (Palisades). This regulation defines the inspection requirement for branch connection butt welds at Palisades in accordance with American Society of Mechanical Engineers Boiler and Pressure Vessel Code Case N-770-1, Alternative Examination Requirements and Acceptance Standards for Class 1 PWR Piping and Vessel Nozzle Butt Welds Fabricated With UNS N06082 or UNS W86182 Weld Filler Material With or Without Application of Listed Mitigation Activities, with NRC conditions. The licensee is requesting an extension of the required inspection for at least one cycle of operation.
The NRC staff is very concerned basing the deferral of any examinations on the structural evaluation of the weld. Weld residual stress calculations are not exact and can have a large uncertainty and may be very sensitive to small changes in assumptions used to develop the flaw evaluations. Therefore the staff needs to know that the welds do not have deep flaws in order to permit operation until the next refueling outage at which time a qualified procedure can be used to exam the welds in accordance with the requirements specified in 10 CFR 50.55a(g)(6)(ii)(F). It is the NRC staffs understanding that these welds have never been volumetrically examined. The NRC staff is particularly concerned with the weld in the hot leg, as temperature is a major factor for crack propagation in primary water stress corrosion cracking.
The NRC staff has reviewed and evaluated the information provided by the licensee and has determined that the following additional information is needed in order to complete its review of the relief request.
1.0 Flaw Analysis RAI-1.14 Provide a detailed discussion of how the post weld heat treatment was physically applied to the welds. What process was physically used to apply the heat treatment to the weld, piping and nozzle?
RAI-1.15 Provide the thickness of the alloy 182/82 cladding on the inside surface of the welds. For the hot leg weld, confirm that the 21-inch inner pipe radius is from the inside surface of the alloy 182/82 cladding.
RAI-1.16 Provide profiles of the weld residual stress through-the-weld that were used in the flaw evaluation for axial flaws. These stress profiles are requested for comparison to the NRC generated stress profiles for this weld configuration. If the licensee did not use specific profiles, explain how the flaw evalution was completed with regard to the stress profile and provide the highest weld residual stress profile through-the-weld from the licensees evaluation for both axial and circumferential flaw growth.
2.0 Non-destructive Examination RAI-2.3 Given the licensees statement, the mockup was used in conjunction with a current PDI-qualified manual phased array procedure, equipment, and personnel to determine if a qualified examination on this complex configuration could be produced. During the testing, known flaws within the mockup specimen could not be reliably detected, describe the site-specific mockup used to test the ultrasonic inspection procedures. Include general size of the mockup, materials, and the following in the response.
A. Provide the flaw types and sizes in the site specific mockup.
B. What flaws were detected with the manual phased array ultrasonic inspection technique?
C. What flaws were not detected?
D. What angles were scanned in performance of this demonstration?
RAI-2.4 In what way does the site specific mockup not meet the requirements of "Site Specific Configuration Mockup Requirements for Dissimilar Metal Welds,"
Revision C (e.g. geometry, flaw types, materials, etc.)
RAI-2.5 Procedures have been developed to exam welds in larger nozzles than the hot leg drain nozzle weld. An ASME Code Section XI Appendix VIII Supplement 10 qualified examination procedure is capable of finding flaws 10% through-wall and greater. Explain the geometric differences between a larger nozzle (ASME Section XI, Table IWB-2500-1, Item number B9.31) and the hot leg drain nozzle that would prevent an ultrasonic examination from detecting a large flaw.
3.0 Proposed Alternative RAI-3.2 The NRC question RAI-3.1 requested the licensee to state the regulatory requirement and how the licensee would meet these requirements. The response by the licensee was to identify a new commitment. However, the staff requests that the licensee submit a new proposed alternative that clearly identifies the regulatory requirements and how those regulatory requirements will be met. The NRC staff would not consider a commitment to be appropriate, and requests the actions be elevated to conditions of the relief. As such, these actions would no longer be regulatory commitments and could not be modified or deleted by the licensee under the commitment management program. Any future changes to these actions would need to be submitted to the NRC for prior review and approval.