RC-15-0009, Relief Request RR-4-07 Request to Use Alternative Root Mean Square (Rms) Depth Sizing Requirements

Relief Request RR-4-07 Request to Use Alternative Root Mean Square (Rms) Depth Sizing Requirements

ML15022A655
Person / Time
Site:	Summer
Issue date:	01/20/2015
From:	Gatlin T South Carolina Electric & Gas Co
To:	Document Control Desk, Office of Nuclear Reactor Regulation
References
CR-14-06288, RC-15-0009, RR-4-07, TAC MD2422
Download: ML15022A655 (6)

Text

Thomas D. Gatlin Vice President,Nuclear Operations SCEi m Gm 803.345.4342 A SCANA COMPANY January 20, 2015 RC-15-0009 Document Control Desk U. S. Nuclear Regulatory Commission Washington, DC 20555

Subject:

VIRGIL C. SUMMER NUCLEAR STATION (VCSNS) UNIT 1 DOCKET NO. 50-395 OPERATING LICENSE NO. NPF-12 RELIEF REQUEST RR-4-07 REQUEST TO USE ALTERNATIVE ROOT MEAN SQUARE (RMS) DEPTH SIZING REQUIREMENTS

Reference:

1. Letter from J. Archie (VCSNS) to Document Control Desk (NRC),

"Request to Use Alternatives to ASME Code Requirements.in VCSNS Third Inservice Inspection Interval (RR-III-03, RR-III-04)," dated June 20, 2006 (ML061720495]

2. Letter from J. Archie (VCSNS) to Document Control.Desk (NRC),

"Supplemental Information Regarding Request to Use Alternatives to ASME Code Requirements in VCSNS Third Inservice.Inspection Interval (RR-III-03, RR-III-04)," dated October 19, 2006

[ML062990461]

3. NRC Letter to J. Archie (VCSNS), "Virgil C. Summer Nuclear Station, Unit NO.1 - Relief Requests RR-111-03 and RR-III-04 (TAC NO.

MD2422)," dated November 21, 2006 [ML063070540]:

South Carolina Electric & Gas Company (SCE&G), acting for itself and as an agent for South Carolina Public Service Authority, hereby submits a request for relief.. In accordance with 10CFR50.55a(z)(1), SCE&G is requesting relief from the American Society of Mechanical Engineers (ASME) Boiler and Pressure Vessel Code,Section XI, "Rules for Inservice Inspection of Nuclear Power Plant Components" in that proposed alternatives would provide an acceptable level of quality and safety.

Specifically, this relief request proposes to use a root. mean square error criterion for sizing flaws that is greater than that allowed by ASME Code for Reactor Pressure Vessel (RPV) nozzles to safe-end cold leg welds. This relief request is similar to relief requests that VCSNS previously submitted for the Third Inservice Inspection Interval (References 1 & 2) that were approved by the NRC in Reference 3 for RPV to safe-end hot leg welds.

ý Virgil C.Summer Station *Post Office Box 88. Jenkinsville, SC .29065. F(803) 941-9776

Document Control Desk CR-14-06288 RC-1 5-0009 Page 2 of 2 SCE&G requests that this repair alternative be approved by October 1, 2015, in support of the upcoming Fall 2015 refueling outage (RF22).

This letter contains no commitments. Should you have any questions, please call Bruce L. Thompson at 803-931-5042.

Very truly yours, Thomas D. Gatlin WLT/TDG/

Enclosure:

VCSNS Relief Request RR-4-07 c: K. B. Marsh S. A. Byrne J. B. Archie N. S. Carns J. H. Hamilton J. W. Williams W. M. Cherry V. M. McCree S. A. Williams NRC Resident Inspector K. M. Sutton NSRC RTS (CR-14-06288)

File (810.19)

PRSF (RC-1 5-0009)

Document Control Desk Enclosure CR-14-06288 RC-1 5-0009 Page 1 of 4 South Carolina Electric & Gas Co. (SCE&G)

Virgil C. Summer Nuclear Station Unit I (VCSNS)

VCSNS Relief Request RR-4-07

1. ASME Code Component(s) Affected The affected VCSNS components are the Class 1, Code Case N-770-1, Inspection Item B, Unmitigated butt weld at Cold Leg operating temperature. The affected welds are:

1-4100A-15 (DM) A "A" Loop Inlet Safe-End Elbow 1-4200A-15 (DM) B "B" Loop Inlet Safe-End Elbow 1-4300A-15 (DM) C "C" Loop Inlet Safe-End Elbow 1-4100A-16 (DM) A "A" Inlet Nozzle to Safe-End 1-4200A-16 (DM) B "B" Inlet Nozzle to Safe-End 1-4300A-16 (DM) C "C" Inlet Nozzle to Safe-End

2. Applicable Code Edition and Addenda ASME Code Section XI, "Rules for Inservice Inspection of Nuclear Power Plant Components," 2007 Edition with 2008 Addenda. Testing of personnel, procedures, and equipment for the ultrasonic examination of applicable Class 1 components is governed by Appendix VIII, "Performance Demonstration for Ultrasonic Examination Systems," of the ASME Code, Section Xl.

3. Applicable Code Requirement The examination of Class 1 and 2 piping welds are required to be performed using procedures, personnel and equipment qualified to the criteria of the ASME Code, Section Xl, Appendix VIII, and specifically Supplement 10, "Qualification Requirements for Dissimilar Metal Pipe Welds," for the examination of nozzle-to-piping dissimilar metal welds.

Paragraph 3.3, "Depth Sizing Test," Subparagraph (c) of Supplement 10 states "examination procedures, equipment, and personnel are qualified for depth sizing when the RMS (root mean square) error of the flaw depth measurements, as compared to the true flaw depths, is less than or equal to 0.125-inch (3 mm)."

4. Reason for Request VCSNS is performing an ultrasonic re-examination of the indicated welds from the inside diameter (ID) surface during the upcoming refueling outage as required by Code Case N-770-1.

Document Control Desk Enclosure CR-14-06288 RC-1 5-0009 Page 2 of 4 VCSNS proposes using an alternative RMS error depth-sizing requirement as compared to the 0.125 inches RMS error value stated in ASME Code,Section XI, Appendix VIII, Supplement 10, Paragraph 3.3, Subparagraph (c). To date, no vendor has been capable of meeting this criterion.

5. Proposed Alternative and Basis for Use 5.1 Proposed Alternative SCE&G proposes to use ASME Code, Section Xl, Appendix VIII, Supplement 10, Paragraph 3.3 with a root mean square error (RMSE) of 0.189 inches instead of the 0.125 inches specified for depth sizing in the Code. In the event that an indication is detected and requires depth sizing, the 0.064 inches difference between the required RMSE and the demonstrated RMSE (0.189-0.125 = 0.064) will be added to the measured through wall extent for comparison to the applicable acceptance standard.

Should the contracted vendor demonstrate an improved depth sizing RMSE prior to the performance of these examinations, the difference of that improved RMSE will be substituted for the 0.189 inches.

5.2 Technical Basis for Proposed Alternative ASME Code Section Xl, "Rules for Inservice Inspection of Nuclear Power Plant Components," 2007 Edition with 2008 Addenda as approved by 10 CFR 50.55a. To date, although examination vendors have qualified for detection and length sizing on these welds, these examination vendors have not met the established RMSE requirement for depth sizing. The contracted vendor for SCE&G has demonstrated the ability to meet the depth sizing qualification requirement with a RMSE of 0.189 inches instead of the 0.125 inches established by the Code Case.

The addition of the difference in allowable depth sizing tolerance from that actually demonstrated to the flaw depths measured will compensate for the possible variance in measured depth.

Document Control Desk Enclosure CR-14-06288 RC-1 5-0009 Page 3 of 4 5.3 Safety Evaluation Compliance The proposed alternative assures that the indicated welds will be fully examined by procedures, personnel and equipment qualified by demonstration in all aspects except depth sizing. In order to compensate for the depth sizing, the addition of the difference between the qualified and demonstrated sizing tolerance will provide an acceptable level of safety and quality in accordance with 10 CFR 50.55a(z)(1). The proposed alternative has been previously approved for VCSNS via NRC Letter dated November 21, 2006, (TAC NO.

MD2422) [ML063070540].

6. Duration of Proposed Alternative This relief request will be implemented during the VCSNS fourth ISI interval, which commenced on January 1, 2014 and ends on December 31, 2023.

This is a new relief request based on ASME Code,Section XI, Appendix VIII, Supplement 10, and the examination vendors' most accurate demonstrated depth sizing performance.

7. Precedents Requests to use an alternative RMSE value have been previously approved by the NRC. In Reference 3, the NRC previously approved the proposed alternative RMSE relief request submitted by VCSNS in References 1 and 2 for hot leg welds. The NRC approved a similar alternative for Point Beach Unit 1 hot leg welds in Reference 6.

Document Control Desk Enclosure CR-14-06288 RC-1 5-0009 Page 4 of 4

8. References

1. Letter from J. Archie (VCSNS) to Document Control Desk (NRC), "Request to Use Alternatives to ASME Code Requirements in VCSNS Third Inservice Inspection Interval (RR-III-03, RR-III-04)," dated June 20, 2006

[ML061720495]

2. Letter from J. Archie (VCSNS) to Document Control Desk (NRC),

"Supplemental Information Regarding Request to Use Alternatives to ASME Code Requirements in VCSNS Third Inservice Inspection Interval (RR-III-03, RR-III-04)," dated October 19, 2006 [ML062990461]

3. NRC Letter to J. Archie (VCSNS), "Virgil C. Summer Nuclear Station, Unit NO.1 - Relief Requests RR-111-03 and RR-111-04 (TAC NO. MD2422)," dated November 21, 2006 [ML063070540]

4. Letter from L. Meyer (NextEra Energy - Point Beach Nuclear Plant, Unit 1) to Document Control Desk (NRC), "10 CFR 50.55a Request, Relief Request 1-RR-4 Re-Examination of the Unit 1 Reactor Pressure Vessel Indication on the 'A' Inlet Nozzle Weld Fifth Ten-Year Inservice Inspection Program Interval," dated November 9, 2012 [ML12318A125]

5. Letter from L. Meyer (NextEra Energy - Point Beach Nuclear Plant, Unit 1) to Document Control Desk (NRC), "Supplement to 10 CFR 50.55a Request, Relief Request 1 -RR-4 Re-Examination of the Unit 1 Reactor Pressure Vessel Indication on the 'A' Inlet Nozzle Weld Fifth Ten-Year Inservice Inspection Program Interval," dated December 14, 2012 [ML12349A364]

6. Letter from L. Meyer (NextEra Energy - Point Beach Nuclear Plant, Unit 1) to Document Control Desk (NRC), "10 CFR 50.55a Request, Relief Request 1-RR-4 Re-Examination of the Unit 1 Reactor Pressure Vessel Indication on the 'A' Inlet Nozzle Weld Fifth Ten-Year Inservice Inspection Program Interval Response to Request for Additional Information," dated February 1, 2013 [ML13035A018]

7. NRC Letter to L. Meyer (NextEra Energy ), "Point Beach Nuclear Plant, Unit 1 - Relief Request 1-RR-4 re: Re-Examination of the Unit 1 RPV Indication on the 'A' Inlet Nozzle Weld (TAC No. ME9905)," dated March 18, 2013

[ML13064A425]