DCL-16-013, Response to NRC Request for Additional Information Regarding Relief Request NDE-FWNS-U1/U2

Response to NRC Request for Additional Information Regarding Relief Request NDE-FWNS-U1/U2

ML16027A358
Person / Time
Site:	Diablo Canyon
Issue date:	01/27/2016
From:	Welsch J Pacific Gas & Electric Co
To:	Document Control Desk, Office of Nuclear Reactor Regulation
References
DCL-16-013, NDE-FWNS-U1/U2
Download: ML16027A358 (4)

Text

Pacific Gas and Electric Company James M. Welsch Diablo Canyon Power Plant Vice President, Nuclear Generation P.O. Box 56 Avila Beach, CA 93424 805.545.3242 E-Mail: JMWl @pge.com January 27, 2016 PG&E Letter DCL-16-013 U.S. Nuclear Regulatory Commission 10 CFR 50.55a ATTN: Document Control Desk Washington, DC 20555-0001 Docket No. 50-275, OL-DPR-80 Docket No. 50-323, OL-DPR-82 Diablo Canyon Power Plant Unit 1 and Unit 2 Response to NRC Request for Additional Information Regarding Relief Request NDE-FWNS-U1/U2

References:

1. PG&E Letter DCL-15-1 06, "ASME Section Xllnservice Inspection Program Request for Relief NDE-FWNS-U 1/U2 to Allow Use of Alternate Examination Volume Coverage Requirements," dated September 3, 2015 (ML15246A244)

2. E-mail communication from NRC, "Diablo Canyon 1 and 2 - RAis for RR NDE-FWNS-U1/U2 to Allow Use of Feedwater Nozzle-to-Vessel Welds Alternate Examination Volume Coverage Requirements," dated December 15, 2015 (ML15350A039)

Dear Commissioners and Staff:

In Reference 1, Pacific Gas and Electric Company (PG&E) submitted relief request NDE-FWNS-U1/U2 for the Diablo Canyon Power Plant Units 1 and 2 third inservice inspection interval for NRC approval. In Reference 2, the NRC Staff provided a request for additional information (RAI) via an e-mail dated December 15, 2015.

The Enclosure to this letter provides PG&E's responses to the RAI questions.

This communication does not contain any new or revised regulatory commitments (as defined by NEI 99-04). If you have any questions or require additional information, please contact Mr. Hossein Hamzehee at (805) 545-4720.

Sincerely,

~/Yl~

James M. Welsch A member of the STARS (Strategic Teaming and Resource Sharing) Alliance Callaway

• Diablo Canyon

• Palo Verde

• Wolf Creek

Document Control Desk PG&E Letter DCL-16-013 January 27, 2016 Page 2 rntt/4231/50033145 Enclosure cc: Diablo Distribution cc/enc: Marc L. Dapas, NRC Region IV Administrator Siva P. Lingam, NRC Project Manager Gonzalo L. Perez, Branch Chief, California Department of Public Health Binesh K. Tharakan, Acting NRC Senior Resident Inspector State of California, Pressure Vessel Unit A member of the STARS (Strategic Teaming and Resource Sharing) Alliance Callaway

• Diablo Canyon

• Palo Verde

• Wolf Creek

Enclosure PG&E Letter DCL-16-013 PG&E Response to NRC Request for Additional Information Regarding Relief Request NDE-FWNS-U1/U2 NRC Question {a):

Identify whether the surface examinations required by ASME Code,Section XI, Table IWC-2500-1, Code Category C-8, Item Number C2.21 were performed for the SG feedwater nozzle-to-she// welds.

PG&E Response:

The surface examinations required by ASME Code,Section XI Table IWC-2500-1, Code Category C-8, Item Number C2.21 were performed for the SG feedwater nozzle-to-shell welds. 100 percent coverage was achieved.

NRC Question {b):

Provide a summary of the results for any surface examinations performed for the steam generator (SG) feedwater nozzle-to-shell welds.

PG&E Response:

The surface examinations did not detect any relevant indications. No defects were noted.

NRC Question {c):

Identify whether relief is also being requested from any of the applicable ASME Code,Section XI surface examination requirements for the SG feedwater nozzle-to-she//

welds.

PG&E Response:

The surface examinations were completed satisfactorily with 100 percent coverage.

Hence, Pacific Gas and Electric Company is not requesting relief from the surface examination requirements of the applicable ASME Code section for these nozzles.

NRC Question {d):

Describe the impact of any surface examinations performed for the SG feedwater nozzle-to-she// welds on the burden and bases assessments included in the relief request.

PG&E Response:

The magnetic particle examination is sensitive to defects that initiate on or propagate to the outside surface of the weld and adjoining examination area. This examination was 1

Enclosure PG&E Letter DC L-16-013 conducted using the ASME Code compliant procedure by qualified examiners and provides assurance that no surface breaking flaws exist on these nozzle welds. Hence, it has no impact on the compliance burden, and it has an ameliorating effect on the basis aspects (that were included in the relief request) due to the added confidence that no structural flaws exist.

2

Pacific Gas and Electric Company James M. Welsch Diablo Canyon Power Plant Vice President, Nuclear Generation P.O. Box 56 Avila Beach, CA 93424 805.545.3242 E-Mail: JMWl @pge.com January 27, 2016 PG&E Letter DCL-16-013 U.S. Nuclear Regulatory Commission 10 CFR 50.55a ATTN: Document Control Desk Washington, DC 20555-0001 Docket No. 50-275, OL-DPR-80 Docket No. 50-323, OL-DPR-82 Diablo Canyon Power Plant Unit 1 and Unit 2 Response to NRC Request for Additional Information Regarding Relief Request NDE-FWNS-U1/U2

References:

1. PG&E Letter DCL-15-1 06, "ASME Section Xllnservice Inspection Program Request for Relief NDE-FWNS-U 1/U2 to Allow Use of Alternate Examination Volume Coverage Requirements," dated September 3, 2015 (ML15246A244)

2. E-mail communication from NRC, "Diablo Canyon 1 and 2 - RAis for RR NDE-FWNS-U1/U2 to Allow Use of Feedwater Nozzle-to-Vessel Welds Alternate Examination Volume Coverage Requirements," dated December 15, 2015 (ML15350A039)

Dear Commissioners and Staff:

In Reference 1, Pacific Gas and Electric Company (PG&E) submitted relief request NDE-FWNS-U1/U2 for the Diablo Canyon Power Plant Units 1 and 2 third inservice inspection interval for NRC approval. In Reference 2, the NRC Staff provided a request for additional information (RAI) via an e-mail dated December 15, 2015.

The Enclosure to this letter provides PG&E's responses to the RAI questions.

This communication does not contain any new or revised regulatory commitments (as defined by NEI 99-04). If you have any questions or require additional information, please contact Mr. Hossein Hamzehee at (805) 545-4720.

Sincerely,

~/Yl~

James M. Welsch A member of the STARS (Strategic Teaming and Resource Sharing) Alliance Callaway

• Diablo Canyon

• Palo Verde

• Wolf Creek

Document Control Desk PG&E Letter DCL-16-013 January 27, 2016 Page 2 rntt/4231/50033145 Enclosure cc: Diablo Distribution cc/enc: Marc L. Dapas, NRC Region IV Administrator Siva P. Lingam, NRC Project Manager Gonzalo L. Perez, Branch Chief, California Department of Public Health Binesh K. Tharakan, Acting NRC Senior Resident Inspector State of California, Pressure Vessel Unit A member of the STARS (Strategic Teaming and Resource Sharing) Alliance Callaway

• Diablo Canyon

• Palo Verde

• Wolf Creek

Enclosure PG&E Letter DCL-16-013 PG&E Response to NRC Request for Additional Information Regarding Relief Request NDE-FWNS-U1/U2 NRC Question {a):

Identify whether the surface examinations required by ASME Code,Section XI, Table IWC-2500-1, Code Category C-8, Item Number C2.21 were performed for the SG feedwater nozzle-to-she// welds.

PG&E Response:

The surface examinations required by ASME Code,Section XI Table IWC-2500-1, Code Category C-8, Item Number C2.21 were performed for the SG feedwater nozzle-to-shell welds. 100 percent coverage was achieved.

NRC Question {b):

Provide a summary of the results for any surface examinations performed for the steam generator (SG) feedwater nozzle-to-shell welds.

PG&E Response:

The surface examinations did not detect any relevant indications. No defects were noted.

NRC Question {c):

Identify whether relief is also being requested from any of the applicable ASME Code,Section XI surface examination requirements for the SG feedwater nozzle-to-she//

welds.

PG&E Response:

The surface examinations were completed satisfactorily with 100 percent coverage.

Hence, Pacific Gas and Electric Company is not requesting relief from the surface examination requirements of the applicable ASME Code section for these nozzles.

NRC Question {d):

Describe the impact of any surface examinations performed for the SG feedwater nozzle-to-she// welds on the burden and bases assessments included in the relief request.

PG&E Response:

The magnetic particle examination is sensitive to defects that initiate on or propagate to the outside surface of the weld and adjoining examination area. This examination was 1

Enclosure PG&E Letter DC L-16-013 conducted using the ASME Code compliant procedure by qualified examiners and provides assurance that no surface breaking flaws exist on these nozzle welds. Hence, it has no impact on the compliance burden, and it has an ameliorating effect on the basis aspects (that were included in the relief request) due to the added confidence that no structural flaws exist.

2