RA-11-012, Regarding Response to Request for Additional Information-Reactor Vessel Beltline Weld Relief Request (RR-23) (ME5407)

Regarding Response to Request for Additional Information-Reactor Vessel Beltline Weld Relief Request (RR-23) (ME5407)

ML110880144
Person / Time
Site:	Robinson
Issue date:	03/23/2011
From:	Alexander D Progress Energy Carolinas
To:	Document Control Desk, Office of Nuclear Reactor Regulation
References
RA-11-012
Download: ML110880144 (3)

Text

ProgessEne y 10 CFR055a 411 Fayetteville Street Mall Raleigh NC 27602 Serial: RA-11-012 March 23, 2011 United States Nuclear Regulatory Commission ATTENTION: Document Control Desk Washington, DC 20555-0001 H. B. ROBINSON STEAM ELECTRIC PLANT, UNIT NO. 2 DOCKET NO. 50-261 / RENEWED LICENSE NO. DPR-23 RESPONSE TO REQUEST FOR ADDITIONAL INFORMATION - REACTOR VESSEL BELTLINE WELD RELIEF REQUEST (RR-23) (ME5407)

Ladies and Gentlemen:

By letter dated January 27, 2011, Carolina Power & Light Company (CP&L), now doing business as Progress Energy Carolinas, Inc., submitted a proposed alternative to the American Society of Mechanical Engineers Boiler and Pressure Vessel Code (ASME Code),Section XI inservice inspection (ISI) requirements regarding examination of certain reactor pressure vessel welds at H. B. Robinson Steam Electric Plant (HBRSEP), Unit No. 2. (ML110330085)

A Request for Additional Information (RAI) was received via electronic correspondence on March 7, 2011. (ML110660469) CP&L's response to the RAI is attached.

No new regulatory commitments have been made in this letter.

If you have questions regarding this submittal, please contact Donna Alexander, Interim Manager, Nuclear Regulatory Affairs, at (919) 546-5357.

Sincerely, Donna Alexander Interim Manager, Nuclear Regulatory Affairs DBM

Attachment:

Response to Request for Additional Information - Reactor Vessel Beltline Weld Relief Request (RR-23) (ME5407) cc USNRC Region II USNRC Resident Inspector - HBRSEP, Unit No. 2 B. Mozafari, NRR Project Manager -HBRSEP, Unit No. 2 wý'

United States Nuclear Regulatory Commission Attachment to RA- 11-012 Attachment Response to Request for Additional Information -

Reactor Vessel Beltline Weld Relief Request (RR-23) (ME5407)

United States Nuclear Regulatory Commission Attachment to RA- 11-012 Page 1 of 1 Response to Request for Additional Information -

Reactor Vessel Beltline Weld Relief Request (RR-23) (ME5407)

Regarding observed indications from the most recent (3rd) inservice inspection (ISI) interval examinations as documented in Table 2 of Proposed Alternative on page 3 of the request dated January 27, 2011:

NRC Request:

Clearly state the location and size of the one indication that was found in the reactor pressure vessel beltline area. Also, state whether this indication was observed in the 1st and/or 2nd ISI interval inspections.

Response

Data from the 3 rd ISI interval inspection shows a sub-surface indication located in the Intermediate Shell-to-Upper Shell circumferential weld 10-273 (identified as RPV 4 in the inspection report). The indication dimensions were recorded as 0.85 inches long, circumferentially, and 0.28 inches deep. The center of the indication is located 26.47 inches counter clockwise from the centerline of longitudinal weld 1-273A (identified as RPV 14 in the inspection report), with an "S"dimension of 2.11 inches.

This indication was observed in the second interval inspection (1990).

This indication was not observed in the first interval inspection (1982).

NRC Request:

State whether the size of the indication changed during the course of the three inspections, and if so, whether the size of the indication could be attributed to improved inspection procedures.

Response

The indication detected in the 2 nd IS, interval inspection was at approximately the same location in weld 10-273. The indication dimensions were recorded as 0.59 inches long, circumferentially, and 0.49 inches deep, with an "S"dimension of 2.35 inches. The difference in size recorded could be attributed to the increased rigor of the demonstration process required by Section XI, Appendix VIII, which was not in effect at the time of the first two interval inspections. The performance demonstration requirements in Appendix VIII substantially improve the ability of an examiner to detect and characterize flaws in examined components.