ML071760221

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Receipt of Report on PNNL Review of Ultrasonic Data on Dissimilar Metal Welds at Duane Arnold Energy Center, Unit 1
ML071760221
Person / Time
Site: Duane Arnold NextEra Energy icon.png
Issue date: 06/22/2007
From: John Honcharik
NRC/NRR/ADES/DCI/CVIB
To: Matthew Mitchell
NRC/NRR/ADES/DCI/CVIB
References
Download: ML071760221 (2)


Text

June 22, 2007 MEMORANDUM TO: Matthew A. Mitchell, Chief Vessels & Internals Integrity Branch Division of Component Integrity Office of Nuclear Reactor Regulation FROM: John Honcharik, Materials Engineer /RA/

Vessels & Internals Integrity Branch Division of Component Integrity Office of Nuclear Reactor Regulation

SUBJECT:

RECEIPT OF REPORT ON PNNL REVIEW OF ULTRASONIC DATA ON DISSIMILAR METAL WELDS AT DUANE ARNOLD ENERGY CENTER, UNIT 1 This memorandum acknowledges the receipt of the enclosed technical evaluation report, "Review of Ultrasonic Data for Flaws Detected at Duane Arnold Energy Center, Unit 1," dated June 18, 2007, from the Pacific Northwest National Laboratory as requested by the Nuclear Regulatory Commission (NRC) staff.

During refueling outage in February 2007, the licensee (FPL Energy) performed ultrasonic (UT) examinations of dissimilar metal welds at Duane Arnold Energy Center, Unit 1 and discovered circumferentially-orientated indications emanating from the inside surface in two recirculation riser safe end-to-nozzle welds. The licensee also reexamined previous UT data from 1999 and 2005. At the request of the licensee the Electric Power Research Institute (EPRI) reviewed the UT data and confirmed that the indications were detectable in the 1999 data. Since past UT examinations did not detect these indications, the NRC staff requested PNNL to conduct an independent assessment of the 1999, 2005 and 2007 UT data to determine the adequacy of the licensee's and EPRI's evaluation, to determine whether these indications should have been detected prior to 2007, and to discuss any reliability issues. The enclosed PNNL report provides this independent assessment of the UT data performed at Duane Arnold Energy Center, Unit 1.

CONTACT: John Honcharik, DCI/CVIB (301) 415-1157

Enclosure:

Technical Evaluation Report

June 22, 2007 MEMORANDUM TO: Matthew A. Mitchell, Chief Vessels & Internals Integrity Branch Division of Component Integrity Office of Nuclear Reactor Regulation FROM: John Honcharik, Materials Engineer /RA/

Vessels & Internals Integrity Branch Division of Component Integrity Office of Nuclear Reactor Regulation

SUBJECT:

RECEIPT OF REPORT ON PNNL REVIEW OF ULTRASONIC DATA ON DISSIMILAR METAL WELDS AT DUANE ARNOLD ENERGY CENTER, UNIT 1 This memorandum acknowledges the receipt of the enclosed technical evaluation report, "Review of Ultrasonic Data for Flaws Detected at Duane Arnold Energy Center, Unit 1," dated June 18, 2007, from the Pacific Northwest National Laboratory as requested by the Nuclear Regulatory Commission (NRC) staff.

During refueling outage in February 2007, the licensee (FPL Energy) performed ultrasonic (UT) examinations of dissimilar metal welds at Duane Arnold Energy Center, Unit 1 and discovered circumferentially-orientated indications emanating from the inside surface in two recirculation riser safe end-to-nozzle welds. The licensee also reexamined previous UT data from 1999 and 2005. At the request of the licensee the Electric Power Research Institute (EPRI) reviewed the UT data and confirmed that the indications were detectable in the 1999 data. Since past UT examinations did not detect these indications, the NRC staff requested PNNL to conduct an independent assessment of the 1999, 2005 and 2007 UT data to determine the adequacy of the licensee's and EPRI's evaluation, to determine whether these indications should have been detected prior to 2007, and to discuss any reliability issues. The enclosed PNNL report provides this independent assessment of the UT data performed at Duane Arnold Energy Center, Unit 1.

CONTACT: John Honcharik, DCI/CVIB (301) 415-1157

Enclosure:

Technical Evaluation Report DISTRIBUTION:

DCI R/F BBateman MEvans KFeintuch MHolmberg,RIII DJackson TChan DHills, RIII ADAMS ACCESSION NO.:

Package: ML071760246 Memorandum: ML071760221 Report: ML071760259 OFFICE DCI/CVIB DCI/CVIB NAME JHoncharik MMitchell DATE 6/21/2007 6/22/2007 OFFICIAL RECORD COPY