HNP-13-058, Relief Request 13R-11 Response to Request for Additional Information

Relief Request 13R-11 Response to Request for Additional Information

ML13150A104
Person / Time
Site:	Harris
Issue date:	05/29/2013
From:	Corlett D Duke Energy Corp, Carolina Power & Light Co
To:	Office of Nuclear Reactor Regulation
References
HNP-13-058, RR 13R-11
Download: ML13150A104 (3)

Text

(~ DUKE David H. Corlett Manager, Regulatory Affairs ENERGY Harris Nuclear Plant 5413 Shearon Harris Road New Hill NC 27562-9300 919 .362 .3137 10 CFR 50 .55a May 29, 2013 Serial: HNP-13-058 Shearon Harris Nuclear Power Plant, Unit 1 Docket No. 50-400

Subject:

Relief Request 13R-11 Response to Request for Additional Information Ladies and Gentlemen:

By letter HNP-13-057 dated May 22, 2013 , Carolina Power & Light Company requested NRC approval of a relief request for the Shearon Harris Nuclear Power Plant, Unit No. 1 (HNP) inservice inspection program, third ten-year interval. HNP will perform a repair to a reactor vessel closure head nozzle penetration utilizing the inside diameter temper bead welding method. HNP determined that repair of the nozzle penetration , utilizing the alternatives specified in the request, would provide an acceptable level of quality and safety.

The NRC staff requested additional information to support their review which was transmitted by letter to HNP (Adams Accession No. ML13144A767). The responses to the request are enclosed .

This document contains no new regulatory commitments .

Please refer any questions regarding this submittal to Mr. John Caves at (919) 362-2406.

Sincerely ,

David H. Corlett

Enclosure:

Relief Request 13R-11 Response to Request for Additional Information cc: Mr. J. D. Austin , NRC Sr. Resident Inspector, HNP Ms. A. T . Billoch Colon , NRC Project Manager, HNP Mr. V . M. McCree, NRC Regional Administrator, Region II

Serial: HNP-13-058 Enclosure Shearon Harris Nuclear Power Plant, Unit No. 1 Docket No. 50-400 / Renewed License No. NPF-63 Relief Request I3R-11 Reactor Vessel Closure Head Nozzles Inservice Inspection Program - Third Interval Response to Request for Additional Information By letter HNP-13-057 dated May 22, 2013, Carolina Power & Light Company requested NRC approval of a relief request for the Shearon Harris Nuclear Power Plant, Unit No. 1 (HNP) inservice inspection program, third ten-year interval. HNP will perform a repair to a reactor vessel closure head nozzle penetration utilizing the inside diameter temper bead welding method. HNP determined that repair of the nozzle penetration, utilizing the alternatives specified in the request, would provide an acceptable level of quality and safety.

The NRC staff requested additional information to support their review which was transmitted by letter to HNP (Adams Accession No. ML13144A767). The responses to the request are provided below.

Question 1:

The licensee indicated in Figure 11 of the relief request that nozzle numbers 5, 17, 29, 35, 38, 49, 59, and 63 have previous indications. Nozzle numbers 5, 17, 38, and 63 have been repaired in accordance with NRC-approved relief request I3R-09. Nozzle number 49 will be repaired in accordance with the subject relief request I3R-11. Discuss the nature of indications in nozzle numbers 29, 35, and 59, and indicate whether or not they will be repaired. If not, provide justification.

Response 1:

Nozzles 29, 35 and 59 were confirmed to contain fabrication indications which are not surface connected. Indications which are not surface connected are not susceptible to primary water stress corrosion cracking (PWSCC) and are not required to be repaired provided they meet construction code acceptance criteria (surface examinations). The Performance Demonstration Initiative (PDI) technique qualification demonstrates that the methodology and analysts can discern fabrication-induced indications from service-induced indications that are not close to the surface. In the event that indications are close to the surface such that the PDI volumetric examination is indeterminate, surface examinations are used to determine whether indications are surface connected and therefore susceptible to PWSCC. The indications identified by the PDI examination in nozzles 29, 35, and 59 were evaluated as described above and determined not to be service-induced flaws indicative of PWSCC. Therefore, repairs are not required. HNP is committed to implementing the requirements of code case N-729-1, including examinations in the next refueling outage, which provides confidence that flaws resulting from PWSCC are identified and repaired to assure public health and safety.

U.S. Nuclear Regulatory Commission Page 2 of 2 Serial HNP-13-058 Enclosure Question 2:

In Section 4, Reason for Request, of the NRC-approved relief request I3R-09, the last repair step was to weld a new lower thermal sleeve assembly at applicable locations. Section 4 of the subject relief request, I3R-11, does not specify welding of a new lower thermal sleeve. Confirm whether (or not) a new lower thermal sleeve assembly will be welded to nozzle number 49.

Response 2:

A lower thermal sleeve assembly will not be welded to nozzle number 49 because it is an open penetration.

Additional Information:

In a conference call on May 29, 2013, the staff inquired whether heat flow calculations or measurement based upon a test coupon would be used to determine interpass temperatures.

Heat flow calculations will be used to determine interpass temperatures for the repair of nozzle 49.