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MONTHYEARML1023006412010-08-16016 August 2010
10 CFR 50.55a Request Number RR-12, Request for Relief from Code Case N-722 Visual Examination of the Reactor Vessel Hot Leg Nozzle to Safe End Dissimilar Metal Welds
Project stage: Request
ML1026500132010-09-21021 September 2010
Acceptance Review E-mail, Relief Request RR-12, from Requirements of ASME Code Case N-722 Visual Examination of Reactor Vessel Hot-Leg Nozzle to Safe End Dissimilar Metal Welds for 4th 10-Year Inservice Inspection Interval (ME4541)
Project stage: Acceptance Review
ML1027801882010-10-0404 October 2010
Email, Draft Request for Additional Information, Relief Request RR-12, from Requirements of ASME Code Case N-722 for Fourth 10-Year Inservice Inspection Interval (ME4541)
Project stage: Draft RAI
ML1027801902010-10-0404 October 2010
Draft Request for Additional Information, Relief Request RR-12, from Requirements of ASME Code Case N-722 for Fourth 10-Year Inservice Inspection Interval (ME4541)
Project stage: Draft RAI
ML1028600872010-10-25025 October 2010
Request for Additional Information, Relief Request RR-12 from ASME Code Case N-722 Visual Examination Requirements for 4th 10-Year Inservice Inspection Interval
Project stage: RAI
ML1029101312010-10-25025 October 2010
Request for Withholding Information from Public Disclosure, 7/30/10 Affidavit Executed by J. Gresham, Westinghouse
Project stage: Withholding Request Acceptance
LIC-10-0095, Response to Request for Additional Information (RAI) Regarding Relief from ASME Code Case N-722 Requirements for Visual Examination of Reactor Vessel Hot Leg Nozzle to Safe End Welds2010-11-0404 November 2010
Response to Request for Additional Information (RAI) Regarding Relief from ASME Code Case N-722 Requirements for Visual Examination of Reactor Vessel Hot Leg Nozzle to Safe End Welds
Project stage: Response to RAI
ML1102001932011-01-14014 January 2011
Withdrawal of Response to Request for Additional Information (RAI) Regarding Request for Relief from ASME Code Case N-722 Requirements for Visual Examination of Reactor Vessel Hot Leg Nozzle-to-Safe End Dissimilar Metal Butt Welds
Project stage: Withdrawal
ML1104705872011-02-16016 February 2011
Request for Additional Information LAR to Revise Technical Specification to Relocate Operating and Surveillance Requirements for the Power Operated Relief Valve
Project stage: RAI
ML1104705882011-02-16016 February 2011
Request for Additional Information
Project stage: RAI
ML1105404412011-02-23023 February 2011
Request for Additional Information, Round 2, Relief Request RR-12 from ASME Code Case N-722 Visual Examination Requirements for 4th 10-Year Inservice Inspection Interval
Project stage: RAI
ML1105404492011-02-23023 February 2011
Request for Additional Information, Round 2, Relief Request RR-12 from ASME Code Case N-722 Visual Examination Requirements for 4th 10-Year Inservice Inspection Interval
Project stage: RAI
ML1106102172011-03-0303 March 2011
Request for Additional Information, Round 2, Relief Request RR-12 from ASME Code Case N-722 Visual Examination Requirements for 4th 10-Year Inservice Inspection Interval
Project stage: RAI
LIC-11-0016, Response to Second NRC Request for Additional Information (RAI) Regarding Request for Relief from ASME Code Case N-722 Requirements for Visual Examination of Reactor Vessel Hot Leg Nozzle-to-Safe End Dissimilar Metal Butt Welds2011-03-0404 March 2011
Response to Second NRC Request for Additional Information (RAI) Regarding Request for Relief from ASME Code Case N-722 Requirements for Visual Examination of Reactor Vessel Hot Leg Nozzle-to-Safe End Dissimilar Metal Butt Welds
Project stage: Request
ML1109103272011-04-0505 April 2011
Verbal Authorization, Request for Relief from Code Case N-722 Visual Examination of the Reactor Vessel Hot-Leg Nozzle-to-Safe-End Dissimilar Metal Welds, 4th 10-Year Inservice Inspection Interval
Project stage: Approval
ML1108309472011-05-17017 May 2011
Request for Withholding Information from Public Disclosure, Affidavit Dated 7/30/10, Executed by J. Gresham, Westinghouse, Report LTR-PAFM-10-123-P, Revision 0
Project stage: Withholding Request Acceptance
ML1122702902011-08-18018 August 2011
Relief Request RR-12 from Code Case N-722, Additional Examinations for PWR Pressure Retaining Welds in Class 1 Components Fabricated with Alloy 600/82/182 Materials, Fourth 10-Year Inservice Inspection Interval
Project stage: Approval
LIC-12-0004, Delay 2012 Refueling Outage and Extend In-service Inspection (ISI) and In-service Test (IST) Intervals2012-01-17017 January 2012
Delay 2012 Refueling Outage and Extend In-service Inspection (ISI) and In-service Test (IST) Intervals
Project stage: Other
2011-02-16
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Text
ENCLOSURE SECOND REQUEST FOR ADDITIONAL INFORMATION REQUEST FOR RELIEF FROM ASME CODE CASE N-722 REQUIREMENTS FOR VISUAL EXAMINATION OF REACTOR VESSEL HOT LEG NOZZLE TO SAFE END WELDS OMAHA PUBLIC POWER DISTRICT, FORT CALHOUN STATION, UNIT NO. 1, DOCKET NO. 50-285 By letter dated August 16, 2010 as supplemented by letter dated January 14, 2011 (Agencywide Documents Access and Management System (ADAMS) Accession Nos. ML102300641 and ML110200193), Omaha Public Power District (the licensee), proposed an alternative to 10 CFR 50.55a(g)(6)(ii)(E) for Fort Calhoun Station, Unit 1. This requirement defines the inservice inspection frequency of visual examination of the reactor vessel hot leg nozzle to safe end welds in accordance with American Society of Mechanical Engineers Boiler and Pressure Vessel Code Case N-722, Additional Examinations for PWR Pressure Retaining Welds in Class 1 Components Fabricated With Alloy 600/82/182 Materials, with NRC conditions. The duration of request is for the fourth 10-year ISI interval which ends on September 25, 2013.
The NRC staff has reviewed and evaluated the information provided by the licensee and has determined that the following information is needed in order to complete its review of the relief request.
- 1. In Reference 8.a of the Attachment to the August 16, 2010 letter, the as built dimension of the Nozzle Extension Forging (a.k.a. safe end) is not provided. The drawing identifies a distance much larger than assumed in the analysis under Ref 9, 10 and 11.
Provide the basis for the distance between the dissimilar metal weld and stainless steel weld used in the analysis.
- 2. It appears from Ref 6 of the Attachment to the August 16, 2010 letter, that the post EPU loads used in the analysis as documented in Table 3-3 were not conservative. Loop 2 loads appear to be used for Deadweight + Normal Operating Thermal, and Loop 1 values were used for Operational Basis Earthquake and Safe Shutdown Earthquake.
However, initial review of Reference 6 indicates the values calculated for the other Loop in each case were higher.
State the basis for using minimum Loop loading values in Table 3-3 of the Attachment to the August 16, 2010 letter.
- 3. Figures 18 and 19 of Reference 11 of the Attachment to the August 16, 2010 letter appear to be the closest stress profiles to the one used to develop Figure 4-1 of the submittal. Figures 18 and 19 included post weld heat treatment, a 25% weld repair and a 5-13/32 inches safe end length.
Provide the basis for the differences between the analysis and results between Figures 18, 19 and 4-1. Specifically, state the basis for the reduction in magnitude of the hoop and axial stresses in the inner half thickness of the nozzle.
ENCLOSURE
- 4. Please, describe the post weld heat treatment procedure used after the dissimilar metal weld was fabricated.
