HNP-10-005, Response to Request for Clarifications Regarding Relief Request 2R1-018

Response to Request for Clarifications Regarding Relief Request 2R1-018

ML100490061
Person / Time
Site:	Harris
Issue date:	02/11/2010
From:	Corlett D Progress Energy Carolinas
To:	Document Control Desk, Office of Nuclear Reactor Regulation
References
HNP-10-005
Download: ML100490061 (6)

Text

Serial:. HNP-i,0-005 10 CFR 50.55a U.S. Nuclear Regulatory Commission ATTENTION: Document Control Desk Washington, DC 20555 SHEARON HARRIS NUCLEAR POWER PLANT, UNIT NO. 1 DOCKET NO. 50-400/RENEWED LICENSE NO. NPF-63 RESPONSE TO REQUEST FOR CLARIFICATIONS REGARDING RELIEF REQUEST 2R1-018

References:

1. Letter from D. H. Corlett to the Nuclear Regulatory Commission (SERIAL:

HNP-08-045), "Second Ten-Year Interval Inservice Inspection Program - Final Documentation Including Requests for Relief in accordance with-10 CFR 50.55a," dated February 05, 2009

2. Letter from D. H. Corlett to the Nuclear Regulatory Commission (SERIAL:

HNP-09-095), "Response to Request for Additional Information Regarding Relief Requests 2R1-018, 2R1-019, 2R1-020, 2R1-021, 2R1-022, 2R2-009, 2R2-010, and 2R2-01 For The Second 10-Year Interval Inservice Inspection Program (TAC NOS. ME0608, ME0609, ME0610, ME061 1, ME0612, ME0613, ME0614, and ME0615)," dated September 24, 2009 Ladies and Gentlemen:

During the December 3, 2009, conference call between the NRC and members of the Harris Nuclear Plant (HNP) staff, the reviewers requested supplemental information as documented via a December 9, 2009, email from M. G. Vaaler, Project Manager. HNP submitted this original Relief Request as Serial: HNP-08-045 (Reference 1), with additional information provided as Serial: HNP-09-095 (Reference 2).

The Enclosure to this letter provides the requested additional information.

This document contains no new or revised Regulatory Commitments.

Please refer any questions regarding this submittal to me at (919) 362-3137.

Sincerely, D. H. Corlett Supervisor -Licensing/Regulatory Programs Harris Nuclear Plant Progress Energy Carolinas, Inc.

Harris Nuclear Plant P. 0. Box 165 New Hill, NC 27562 14v04

HNP- 10-005 Page 2 DHC/kms

Enclosure:

Response to Supplemental Questions on Relief Request 2R 1-018 cc: Mr. J. D. Austin, NRC Sr. Resident Inspector, HNP Mr. L. A. Reyes, NRC Regional Administrator, Region II Mr. R. Winegarden, Harris Plant Authorized Nuclear Inservice Inspector Ms. M. G. Vaaler, NRC Project Manager, I-TNP

Enclosure to SERIAL: HNP-10-005 SHEARON HARRIS NUCLEAR POWER PLANT, UNIT NO. 1 DOCKET NO. 50-400/RENEWED LICENSE NO. NPF-63 RESPONSE TO SUPPLEMENTAL QUESTIONS ON RELIEF REQUEST 2R1-018 Summary Carolina Power & Light Company, now doing business as Progress Energy Carolinas, Inc.,

(PEC) submitted Relief Request (RR) 2R1-018 for the Harris Nuclear Plant (HNP). The proposed RR is for the second 10-year inservice inspection (ISI) interval, in which the licensee adopted the 1989 Edition of the ASME Code,Section XI, no Addenda, as the Code of Record.

Per the conference call on December 3, 2009, between the NRC and members of the Harris staff, the following supplemental information was requested in regard to relief request 2R1-018.

Request 1: Please verify that the welds in RR 2R1-018 are a part of the reactor pressure vessel (RPV)

Response: The Inlet Nozzle Dissimilar Metal (DM) welds are located off the Reactor Vessel at the Elbow to Nozzle, as depicted in the following:

SERIAL: HNP-09-095 (Reference 2):

Enclosure 2, page 8 of 10, Reactor Vessel drawing, 1-ISI-RV-1 Enclosure 2, page 9 of 10, Reactor Vessel drawing, 1-ISI-RV-A600 These examinations are performed in conjunction with the Reactor Vessel examination using the same equipment and nomenclature.

Request 2: Please verify that the inspections were conducted from the inner diameter of the weld (ID)

Response: All examinations were performed from the inner diameter (ID) of the weld, as provided in the following:

SERIAL: HNP-08-045 (Reference 1), Section 5.0:

".... volumetric examination for the subject welds at HNP is restricted due to geometric surfaces (inner diameter surface counter-bore and root configuration) which limit accessibility and make the 100 percent volumetric examination impractical for these areas."

SERIAL: HNP-09-095 (Reference 2): "ID" typed in "Examination Surface" boxes in the following:

Enclosure 2, Attachment A, Analysis Log # SE-95-1 Enclosure 2, Attachment B, Analysis Log # SE-215-1 Enclosure 2, Attachment C, Analysis Log # SE-335-1 Page 1 of 4

Enclosure to SERIAL: HNP-10-005 SHEARON HARRIS NUCLEAR POWER PLANT, UNIT NO. 1 DOCKET NO. 50-400/RENEWED LICENSE NO. NPF-63 RESPONSE TO SUPPLEMENTAL QUESTIONS ON RELIEF REQUEST 2R1-018 Request 3: Please verify that the eddy current inspection was a full coverage exam Response: The Eddy Current examinations were full coverage, i.e. 100% of the ID surface of the required examination volume per ASME Section XI Figure IWB-2500-8 examination surface E-F, as presented in:

SERIAL: HNP-09-095 (Reference 2): "100" for "CCW" and "CW" in "ET" columns in the following:

Enclosure 2, Attachment A, RPV Coverage Estimate Breakdown, Weld No. RVNOZCl-N-05SE Enclosure 2, Attachment B, RPV Coverage Estimate Breakdown, Weld No. RVNOZB l-N-03 SE Enclosure 2, Attachment C, RPV Coverage Estimate Breakdown Weld No. RVNOZA1-N-01SE Request 4: Please expand upon the description of the difference(s) between the 1996 and 2006 weld inspections Response: During the first interval, the UT examinations were performed by a different vendor using different equipment, resulting in different coverage limitations. The transducers used by the vendor in 1996 had a 3/8" by 1" footprint, while the transducers used by the 2006 vendor had a 22mm x 22mm footprint. In 2006, each of the transducers was individually gimbaled within the examination sled to maximize compliance with the ID surface of the nozzles.

Additionally, this 2006 combination of technique and equipment was qualified to ASME Code,Section XI, Appendix VIII, as administered by the EPRI PDI, while the method utilized in 1996 was not ASME Code, Appendix VIII, PDI qualified.

There were no supplemental Eddy Current examinations performed during the first interval examinations. For 2006, an Eddy Current examination with 100% surface coverage was performed.

Request 5: Please provide a more detailed description and/or explanation of the limitations of the weld inspection technique(s) used Response: These inspections were performed from the ID surface of the Elbow to Nozzle examination area, an area that is not accessible for a direct visual inspection to determine existing obstructions resulting in the limited coverage. Discussions with an industry expert found that in an elbow to nozzle configuration, a counterbore would typically be required to better provide for ID mismatch. In addition, the root may have some type of protrusion that Page 2 of 4

Enclosure to SERIAL: IHNP-10-005 SHEARON HARRIS NUCLEAR POWER PLANT, UNIT NO. 1 DOCKET NO. 50-400/RENEWED LICENSE NO. NPF-63 RESPONSE TO SUPPLEMENTAL QUESTIONS ON RELIEF REQUEST 2R1-018 could limit the examination, although this does not appear likely due to the complete coverage for the supplemental eddy current examination.

The examinations were limited in the circumferential direction only, specifically in areas of counterbore and/or root. The qualified inspection procedure used has no limitations due to surface configuration for axial scanning. The axial direction scans, looking for the more critical circumferential flaws, achieved 100% coverage.

The ID configuration of the Elbow to Nozzle examination area was profiled with an immersion zero degree transducer. The data from this profiling was used to determine areas where circumferential scanning transducer contact was compromised to an extent greater than the EPRI guideline of 1/32" of the contact area of the transducer.

Request 6: Please clarify the wave mode(s) and angles used for the inspection Response: All the examinations were performed to a qualified PDI procedure. The Inlet Nozzle Dissimilar Metal (DM) welds were examined using a 70 ° Longitudinal (refracted L) wave dual probe, as presented:

SERIAL: HNP-09-095 (Reference 2):

Enclosure 2, page 3 of 10, "70' Longitudinal Wave Dual Scan,"

Component ID RVNOZC l-N-05SE Enclosure 2, page 4 of 10, "70' Longitudinal Wave Dual Scan,"

Component ID RVNOZBl-N-03SE Enclosure 2, page 5 of 10, "70' Longitudinal Wave Dual Scan,"

Component ID RVNOZA1-N-01SE Request 7: Please provide an additional explanation of the eddy current technique used in this inspection (reference: V.C. Summer submittal dated June 20, 2006)

Response: The eddy current technique used was a surface examination technique. Per the examination vendor Wesdyne, a Westinghouse NDE Company, this exam was used to supplement the UT in areas of limited contact due to its smaller contact area (0.25"dia vs. 0.87" x 0.87" square for the UT transducers) and assisted in the characterization of any potential surface breaking ID connected PWSCC flaws, a concern for this component.

The eddy current technique parameters utilized:

- Up to two plus point probes applied circumferentially on the ID surface in scan increments of 0.80 inches (for axial flaws) and 0.25 inches axially.

- Automated systems for data collection and analysis.

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Enclosure to SERIAL: HNP-10-005 SHEARON HARRIS NUCLEAR POWER PLANT, UNIT NO. 1 DOCKET NO. 50-400/RENEWED LICENSE NO. NPF-63 RESPONSE TO SUPPLEMENTAL QUESTIONS ON RELIEF REQUEST 2R1 -018 The target flaw size for the eddy current procedure is 0.28 inches long, which is well within the ASME Code linear flaw acceptance standard of 0.45 inches long for austenitic materials (as defined for the outside surface in the ASME Code Tables).

As provided by Wesdyne, the eddy current technique was developed to augment the ultrasonic examination method and to provide increased sensitivity at the ID surface. The eddy current technique was first used in the VC Summer reactor vessel primary nozzle examinations of 2000.

The procedure was refined after its first use in 2000 by applying it to the VC Summer hot leg dissimilar metal weld section removed from service. The removed section had a number of primary water stress corrosion cracking flaws along with non-relevant indications resulting from metallurgical interface and surface geometry. Using these actual flaws and geometric conditions in the removed section to refine the technique, Wesdyne developed reliable flaw-screening criteria which allowed for the successful use of the procedure in the VC Summer 2002 and 2003 examinations.

Since that time, the technique has been successfully blind tested at the Swedish NDT Qualification Centre (SQC Kvalificeringscentrum AB) under the program, "Qualification of Equipment, Procedure and Personnel for Detection, Characterization and Sizing of Defects in Areas in Nozzle to Safe End Welds at Ringhals Unit 3 and 4," Hakan Soderstrand 7-10-03. The important qualification parameters for Eddy Current in the SQC blind tests were as follows:

-Defect types: fatigue and stress corrosion cracks, surface initiated

-Tilt: +/- 10 degrees; Skew: +/- 10 degrees

-Detection target size: IDSCC 6mm (0.25 inches) long

-Flaw Location: within 10mm (13/32 inch)

-Length of the planar flaw within a 70% confidence interval: +/-9mm (3/8 inch)

-False call rate: less than or equal to 20% for the personnel qualification tests The technique has also been used to supplement examination of portions of the relevant near-surface volumes during more than 20 domestic pressurized water reactor nozzle-to-pipe examinations conducted by Wesdyne.

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