NG-97-0078, Submits Clarification & Justification Re ISI Alternative Exam Requests NDE-020 & NDE-R011.GENE 955-009-0197 Rept Encl

Submits Clarification & Justification Re ISI Alternative Exam Requests NDE-020 & NDE-R011.GENE 955-009-0197 Rept Encl

ML20133Q330
Person / Time
Site:	Duane Arnold
Issue date:	01/21/1997
From:	Peveler K IES UTILITIES INC., (FORMERLY IOWA ELECTRIC LIGHT
To:	NRC (Affiliation Not Assigned), NRC OFFICE OF INFORMATION RESOURCES MANAGEMENT (IRM)
Shared Package
ML20133Q334	List: ML20133Q381 NG-97-0078, Submits Clarification & Justification Re ISI Alternative Exam Requests NDE-020 & NDE-R011.GENE 955-009-0197 Rept Encl
References
NG-97-0078, NG-97-78, NUDOCS 9701280062
Download: ML20133Q330 (4)

Text

\

• Duane Amold Energy Center a, 3277 DAE C Road Palo.L35:3 N Telephone 319 8517611 Fax 319 851761I UTILITIES January 21,1997 NG-97-0078 Office of Nuclear Reactor Regulation U. S. Nuclear Regulatory Commission

)

Attn: Document Control Desk i Mail Station Pl-37 l Washington, DC 20555-0001 1

Subject:

Duane Arnold Energy Center Docket No: 50-331 Op. License No: DPR-49 Clarification and Justification Concerning Inservice Inspection .

Alternative Examination Requests NDE-020 and NDE-R011 I i

)

References:

1) NG-96-0809, from J. Franz (IES) to W. Russell (NRC) dated <

April 26,1996, Third 10-Year Interval Inservice Inspection Plan

2) NG-96-2088, from K.E. Peveler (lES) to Office of Nuclear Reactor Regulation (NRC) dated October 3,1996, Inservice Inspection Relief Requests

3) NG-96-2574 from K.E. Peveler to Office of Nuclear Reactor Regulation (NRC) dated November 26,1996, Additional Information on Inservice Inspection Relief Requests NDE-020 and  ;

NDE-R011 File: A-100, A-286

Dear Sirs:

Reference 1 transmitted the Duane Arnold Energy Center (DAEC) Third 10-Year Interval Inservice Inspection (ISI) Plan, along with several relief requests requiring NRC approval. Included was Second-10 Year interval relief request NDE-020. Reference 2 transmitted a revision to relief request NDE-020, and Third 10-Year Interval relief request NDE-ROI1. During a conference call on November 18,1996, the Staff requested additional information regarding relief requests NDE-020 and NDE-ROI1. The requested information was provided in reference 3. In another telephone call on December 6,1996, the Staff requested further clarification. The requested further clarification and l justification for relief requests NDE-020 and NDE-R011 is provided in attachment I to this letter. Relief Requests NDE-R011 and NDE-020 were changed to Alternative Examination Requests to meet the intent of 10CFR50.55a(3)(i).

Ag

9701200062 970121 PDR ADOCK 05000331 G PDR An IES Indastnes Company

NG-97-0078

' January 21,1997 Page 2 l

l For Alternative Examination Request NDE-R011 we have added Examination Category l

B-D, item Numbers B3.90 and B3.100, as well as additionaljustification. For Alternative Examination Request NDE-020 we have added Examination Category B-A, Item Numbers Bl.20. Bl.30. Bl.40 and Examination Category B-D, Item Numbers B3.90 and B3.100, as well as additionaljustification.

Should you have any questions regarding this matter, please contact this office.

1 Sincerely, h .c// b f Kenneth E. Peveler Manager, Regulatory Performance Attachments: (1) Clarification and Justification for Altemative Examination Requests '

NDE-R011and NDE-R020 (2) Alternative Examination Number: NDE-R011 (3) IES Utilities Inc. Duane Arnold Energy Center 2nd 10-Year Interval l Alternative Examination Number: NDE-020 cc: D. Barta L. Root G. Kelly (NRC-NRR)

D. Weaver ('NRC-NRR)

A. B. Beach (Region Ill)

NRC Resident Office Docu i

1

' Attachment I to NG-97-0078 Page1of2 i

Clarification and Justification for Alternative Examination i Requests NDE-R011 and NDE-R020 )

i

( The Reactor Pressure Vessel (RPV) and Nozzle-to-Vessel Welds were examined in .

l '

accordance with GE (General Electric) procedure "UT-DAC-702VO", which was j demonstrated at the EPRI (Electrical Power Research Institute) NDE (Nondestructive i

Examination) Center under the PDI (Performance Demonstration Initiative) Program.

The procedure was qualified in detection and sizing in accordance with ASME Section XI, Appendix VIII, Supplement 6. In addition, the procedure was airo successful in the

l detection of under clad flaws (ASME Section XI, Appendix VIII, Supplement 4,0.52" X l.1" (single side exam) and 0.27" X i.1" (double side exam)).

a The examinations performed met all of the requirements specified in Regulatory Guide

1.150, (Ultrasonic Testing of Reactor Vessel Welds During Preservice and Inservice l' Examinations), including transducer beam profiles. All other ASME Section XI requirements were met. A demonstration witnessed by the ANil(Authorized Nuclear

, inservice Inspector) was performed which showed that a dynamic calibration on the

existing calibration blocks with the side-drilled holes to a depth of 1.5" was acceptable.

A review of the " edge effect" using theoretical and empirical approaches has been completed. A discussion of each approach follows:

, Theoretical i

A comparison of the responses from a 60 shear wave signal from the DAEC Calibration i Block with 1.5" side-drilled holes to an ASME Calibration Block with 3" side-drilled I holes was completed using AutoCad. The comparison showed that the sensitivity for the 1.5" holes was more than the 3" holes thus proving that the " edge effect" did not reduce the examination sensitivity.

Empirical To support the theoretical approach, data was collected from an ASME Calibration Block with 3" side-drilled holes. The data was taken on the block starting 0.25" from the edge of the block and at 0.25" increments along the length of the holes. Angles of 0 ,45 , and 60 were used. The results were compared with the angles used during the DAEC Vessel Examination. This concluded that the sensitivity used in the examination using the DAEC calibration block was higher than that which would have been used when calibrating on an ASME Calibration Block.

Attachment I to NG-97-0078 Page 2 of 2 Enclosed is the General Electric Report, GERIS 2000 AND MANUAL EXAM SENSITIVITY FOR RPV WELD EXAMINATIONS AT DUANE ARNOLD ENERGY CENTER, GENE 955-009-0197, which provides the details of the comparisons stated above.

CONCLUSION The GERIS 2000 and manual RPV weld examinations at the DAEC were slightly more sensitive when calibrated on blocks containing 1.5" deep side-drilled holes than they would have been using an ASME standard configuration block.

There was no detectable effect due to transducer placement near the edge of the block (edge effect) for angle beam examinations at the DAEC. Calibration sensitivity using 1.5" deep side-drilled holes with the search unit placed at approximately .73" from the edge of the block was slightly higher, from 1.7dB (45 ) to 5.0dB (60 ), than calibrations using 3" deep holes with the search unit placed at 1.5" from the edge.

There was an apparent edge effect on straight beam calibrations using 3" deep holes with I the search unit about 1.25" from the edge. There appears to be a side lobe reinforcement l of the amplitude from the 1/4T,1/2T, and 3/4T holes. The effect is on the order of 6dB.

When this effect is considered, the calibration sensitivity using 1.5" deep side-drilled holes with the search unit placed at approximately .75" from the block edge was about 14dB higher than calibrations using 3" deep holes with the search unit placed 1.5" from the edge. I RPV weld examinations at the DAEC met the sensitivity requirements of ASME Sect sn XI,1989 Edition with no Addenda and earlier Editions. The examinations were performed in accordance with USNRC Regulatory Guide 1.150 requirements.

l l