ML20280A513

Response to Request for Additional Information - End of Interval Relief Request Associated with the Fourth Ten-Year Inservice Inspection (ISI) Interval

ML20280A513
Person / Time
Site:	Calvert Cliffs
Issue date:	10/06/2020
From:	David Helker Exelon Generation Co
To:	Document Control Desk, Office of Nuclear Reactor Regulation
References
Download: ML20280A513 (6)

Text

200 Exelon Way Kennett Square, PA 19348 www.exeloncorp.com 10 CFR 50.55a October 6, 2020 U.S. Nuclear Regulatory Commission Attn: Document Control Desk Washington, DC 20555-0001 Calvert Cliffs Nuclear Power Plant, Units 1 and 2 Renewed Facility Operating License Nos. DPR-53 and DPR-69 NRC Docket Nos. 50-317 and 50-318

Subject:

Response to Request for Additional Information - End of Interval Relief Request Associated with the Fourth Ten-Year Inservice Inspection (ISI)

Interval

References:

1) Letter from D. Helker (Exelon Generation Company, LLC) to U.S. Nuclear Regulatory Commission, End of Interval Relief Request Associated with the Fourth Ten-Year (ISI) Interval, dated June 18, 2020

2) Email from M. Marshall (U.S. Nuclear Regulatory Commission) to T.

Loomis (Exelon Generation Company, LLC), Calvert Cliffs Nuclear Power Plant, Units 1 and 2 Request for Additional Information Regarding Alternative Request Re: Inservice Inspection Impracticality (L-2020-LLR-0089), dated September 30, 2020 (ML20275A003)

In the Reference 1 letter, Exelon Generation Company, LLC (Exelon), requested relief from the American Society of Mechanical Engineers (ASME) Boiler and Pressure Vessel (B&PV)

Code,Section XI, Rules for Inservice Inspection of Nuclear Power Plant Components. This relief request applies to the fourth ten-year Inservice Inspection (ISI) interval, which concluded on June 30, 2019, for the Calvert Cliffs Nuclear Power Plant, Units 1 and 2.

In the Reference 2 email, the U.S. Nuclear Regulatory Commission Staff requested additional information. Attached is our response.

There are no regulatory commitments in this letter.

Response to RAI - End of Interval Relief Request Associated with the Fourth Ten-Year Inservice Inspection (ISI) Interval October 6, 2020 Page 2 If you have any questions concerning this letter, please contact Tom Loomis at (610) 765-5510.

Respectfully, David P. Helker Sr. Manager - Licensing Exelon Generation Company, LLC

Attachment:

Response to Request for Additional Information cc: Regional Administrator, Region I, USNRC USNRC Senior Resident Inspector, CCNPP Project Manager USNRC S. Seaman, State of Maryland

Attachment Response to Request for Additional Information

Response to Request for Additional Information Page 1 Question:

The U.S. Nuclear Regulatory Commission staff has reviewed the information provided in the LAR and has determined that additional information is needed to complete its review. The request for additional information (RAI) was discussed with Exelon on September 29, 2020, and it was agreed that the response would be provided within 30 days of the date of this email

[dated September 30, 2020].

Specifically, pursuant to Title 10 of the Code of Federal Regulations (10 CFR) 50.55a(g)(5)(iii),

the licensee requested relief on the basis that achieving the ASME Code-required examination coverage for the subject welds in RR ISI-04-25 is impractical. Regulations in 10 CFR 50.55a(g)(5)(iii), state that when licensees determine that conformance with ASME Code requirements is impractical at their facility, they shall submit information to support this determination. 10 CFR 50.55a(g)(6)(i), states in part that the Commission will evaluate such requests based on impracticality, and may impose alternatives, giving due consideration to public safety and the burden imposed on the licensee.

The staff noted that for certain welds, the inspection reports in Attachments 2 and 3 to the letter dated June 18, 2020 did not include the following information:

• recordable indication(s),

• acceptable indication(s), or

• whether the examination was acceptable.

This information is necessary for the staff to evaluate the extent of active aging degradation in these components. The staff requests that the licensee provide the aforementioned information regarding examination results for each of the welds in the tables below.

Unit 1 Component ID Description Page Numbers in Attachment 2 SG-11-W7 11B Primary Head to Cold Pages 5-11 Leg B Nozzle SG-12-W6 12A Primary Head to Cold Pages 15-21 Leg A Nozzle SG-12-W7 12B Primary Head to Cold Pages 22-28 Leg B Nozzle)

SG-11-W6 11A Primary to Cold Leg A Pages 71-78 Nozzle) 16-405A Nozzle to Head Weld Pages 56-60 16-405B Nozzle to Head Weld Pages 61-65 10-205A Nozzle to Shell Pages 79-81 10-205B Nozzle to Shell Pages 82-84

Response to Request for Additional Information Page 2 Unit 2 Component ID Description Page Numbers in Attachment 3 4-404 Lower Head Surge Line Pages 2-14 Nozzle, 4-405 Upper Head Spray Nozzle Pages 15-22 SG-21-W7 Primary Head to Class B Pages 23-30 Nozzle Extension 10-205A Outlet Nozzle at 0 Degrees Pages 126-129 10-205B Outlet Nozzle at 180 Pages 130-133 Degrees

Response

For the identified welds, the following are two tables that provide a listing of recordable indication(s), acceptable indication(s), and the acceptance of the indication.

Unit 1:

Page Component Numbers in Description Indication(s) Remarks ID Attachment 2

11B Primary Head to The examination was SG-11-W7 Pages 5-11 No Cold Leg B Nozzle acceptable.

12A Primary Head to The examination was SG-12-W6 Pages 15-21 No Cold Leg A Nozzle acceptable.

12B Primary Head to The examination was SG-12-W7 Pages 22-28 No Cold Leg B Nozzle) acceptable.

11A Primary to Cold The examination was SG-11-W6 Pages 71-78 No Leg A Nozzle) acceptable.

The examination was 16-405A Nozzle to Head Weld Pages 56-60 No acceptable.

The examination was 16-405B Nozzle to Head Weld Pages 61-65 No acceptable.

All 10 indications were found 10-205A Nozzle to Shell Pages 79-81 Yes to be acceptable per IWB-3512-1.

All 7 indications were found to 10-205B Nozzle to Shell Pages 82-84 Yes be acceptable per IWB-3512-1.

Response to Request for Additional Information Page 3 Unit 2:

Page Component Numbers in Description Indication(s) Remarks ID Attachment 3

2 indications were found during the examination. One indication was a result of Lower Head Surge bore geometry. The other 4-404 Pages 2-14 Yes Line Nozzle, indication was a spot indication with no measurable through wall dimension. Both indications were acceptable.

Upper Head Spray The examination was 4-405 Pages 15-22 No Nozzle acceptable.

Primary Head to Class The examination was SG-21-W7 Pages 23-30 No B Nozzle Extension acceptable.

All 2 indications were found to Outlet Nozzle at 0 Pages 126-10-205A Yes be acceptable per IWB-3512-Degrees 129 1.

The 1 indication was found to Outlet Nozzle at 180 Pages 130-10-205B Yes be acceptable per IWB-3512-Degrees 133 1.