L-2012-381, Fourth Ten-Year Interval, Relief Request No. 10

Fourth Ten-Year Interval, Relief Request No. 10

ML12340A070
Person / Time
Site:	Turkey Point
Issue date:	11/13/2012
From:	Kiley M Florida Power & Light Co
To:	Document Control Desk, Office of Nuclear Reactor Regulation
References
L-2012-381
Download: ML12340A070 (6)

Text

0 NOV 13 2012 FPL. L-2012-381 10 CFR 50.55a U.S. Nuclear Regulatory Commission Attn: Document Control Desk Washington, DC 20555-0001 RE: Turkey Point Units 3 and 4 Docket Nos. 50-250 and 50-251 Inservice Inspection Plan Fourth Ten-Year Interval, Relief Request No. 10 Pursuant to 10 CFR 50.55a(a)(3)(i), Florida Power and Light (FPL) requests relief from Code requirements for Ultrasonic (UT) examination of the Class 1 Reactor Pressure Vessel (RPV) Upper Shell-to-Flange Weld for Turkey Point's Units 3 and 4 Fourth Inservice Inspection Interval.

As an alternative to the requirements specified in ASME Section Xl, Appendix I, Article 1-2110(b), FPL proposes to use procedures, personnel, and equipment qualified to the requirements of ASME Section Xl, Appendix VIII, Supplements 4 and 6 of the 1998 Edition with Addenda through 2000, as administered by the Electric Power Research Institute (EPRI) Performance Demonstration Initiatives (PDI) program to conduct the reactor vessel upper shell-to-flange weld examination.

The attached Relief Request No. 10 is essentially the same as previously approved in the NRC safety evaluation dated March 23, 2012, "St. Lucie Unit No. 2- Relief from the Requirements of the ASME Code Relief Request No. 12 (TAC No. ME6745 and Adams Accession No: ML12062A146).

FPL requests the approval of the attached relief request to support the refueling outages for Turkey Point Unit 3 Cycle 27, and Turkey Point Unit 4 Cycle 28.

If you have any questions or require additional information, please contact Robert Tomonto, Licensing Manager, at (305) 246-7327.

Very truly yours, Michael Kiley Site Vice President Turkey Point Nuclear Plant cc: Regional Administrator, Region II, USNRC Senior Resident Inspector, USNRC, Turkey Point Plant t4oA7 Florida Power Light Company 9760 S.W. 344 Street Homestead, FL 33035

L-2012-381 Attachment Page 1 of 5 Turkey Point Units 3 & 4 Fourth Inservice Inspection Interval Relief Request Number 10 Proposed Alternative In Accordance with 10 CFR 50.55a (a)(3)(i)

Alternative Provides Acceptable Level of Quality and Safety "ALTERNATIVE ULTRASONIC EXAMINATION FOR THE REACTOR PRESSURE VESSEL UPPER SHELL-TO-FLANGE WELD USING ASME SECTION Xl, APPENDIX VIII DEMONSTRATED TECHNIQUES"

1. ASME Code Component(s) Affected Class 1 Reactor Pressure Vessel (RPV) Upper Shell-to-Flange Welds (Weld Number 3-WR-18 and 4-WR-18) subject to Ultrasonic (UT) examination.

2. Applicable Code Edition and Addenda

Turkey Point Units 3 & 4 are currently in the 4th 10-year Inservice Inspection (ISI) interval. The American Society of Mechanical Engineers (ASME) Boiler and Pressure Vessel Code (Code) of record for the current 10-year ISI interval is Section Xl, is 1998 Edition with Addenda through 2000.

3. Applicable Code Requirement

ASME Code Class 1, Table IWB-2500-1, "Pressure Retaining in Reactor Vessel,"

Examination Category B-A, Item Number B1.30, "Shell-to-Flange Weld". ASME Section XI, Paragraph IWA-2232 states, "Ultrasonic examinations shall be conducted in accordance with Appendix I." Appendix I, Article 1-2110(b), requires "Ultrasonic examination of reactor vessel-to-flange welds, closure head-to-flange welds, and integral attachment welds shall be conducted in accordance with Article 4 of Section V, except that alternative beam angles may be used. These examinations shall be further supplemented by Table 1-2000-1."

Exam Item No. Examination Description Cat.

Essentially 100% volumetric examination of the reactor B-A B1.30 vessel-to-flange weld in accordance with Appendix I, Article 1-2110(b)

L-2012-381 Attachment Page 2 of 5 Turkey Point Units 3 & 4 Fourth Inservice Inspection Interval Relief Request Number 10

4. Reason for Request

FPL is performing volumetric examinations of all Reactor Pressure Vessel (RPV) welds during the Fourth 10-year Inservice Inspection (ISI) interval. FPL is required to perform the 10-year RPV ISI pursuant to 10CFR50.55a. The Code requires that Ultrasonic (UT) examination of RPV welds, excluding the reactor vessel upper shell-to-flange weld, shall be with techniques that have been demonstrated in accordance with ASME Section Xl, Appendix VIII.

Examination from the inside surface provides the best access for examination of the reactor vessel upper shell-to-flange weld. The outside surface of the RPV is inaccessible due to it's placement inside the biological-shield wall and the installed insulation.

Although the reactor vessel upper shell-to-flange weld is specifically excluded from the requirement to utilize ASME Section Xl, Appendix VIII qualified UT techniques by the referenced Code, FPL believes that performing the UT examination with Appendix VIII/PDI qualified personnel and procedures from the inside surface will provide an acceptable level of quality and safety.

5. Proposed Alternative and Basis for Use Proposed Alternative:

As an alternative to the requirements specified in ASME Section XI, Appendix I, Article 1-2110(b), FPL proposes to use procedures, personnel, and equipment qualified to the requirements of ASME Section XI, Appendix VIII, Supplements 4 and 6 of the 1998 Edition with Addenda through 2000, as administered by the Electric Power Research Institute's (EPRI) Performance Demonstration Initiatives (PDI) program to conduct the reactor vessel upper shell-to-flange weld examination. The examinations from the inside surface will be implemented to achieve the maximum coverage possible utilizing procedures and personnel qualified by the PDI Program. The proposed alternative represents the best techniques, procedures, and qualifications available to perform UT examinations of RPV welds. The PDI Program addresses qualification requirements for each of the supplements that are defined in ASME Section XI, Appendix VIII. The applicable vendor procedure has been qualified in accordance with PDI's implementation of Supplements 4 and 6 of ASME Section XI, Appendix VIII.

Basis for Use:

The listed weld is the only circumferential shell weld in the reactor vessel that is not examined with ASME Section XI, Appendix VIII techniques, as mandated by

L-2012-381 Attachment Page 3 of 5 Turkey Point Units 3 & 4 Fourth Inservice Inspection Interval Relief Request Number 10 10CFR50.55a. 10CFR50.55a mandates the use of ASME Section Xl, Appendix VIII, Supplements 4 and 6 for the conduct of all other reactor vessel weld examinations.

ASME Section Xl, Appendix I, Article 1-2110(b) identifies that ASME Section V, Article 4 techniques be utilized for the examination of the reactor vessel-to-flange weld. The calibration techniques, recording criteria, and flaw sizing methods are based upon the use of a distance-amplitude-correction (DAC) curve derived from the ultrasonic responses to machined reflectors in a basic calibration block. Reflectors detected in the field require investigation only if they exceed 20% of the amplitude response of the DAC curve obtained from the machined reflectors in the basic calibration block.

Indications detected in the designated examination volume with amplitudes below this threshold are therefore, not required to be recorded. The amplitude based recording threshold is generic and does not take factors into consideration such as flaw orientation, which can influence the amplitude of the UT response. Use of the ASME Section Xl, Appendix VIII, qualified techniques enhance the quality of the examination.

The detection criterion is more conservative because the qualified procedure requires examiners to measure and evaluate all indications determined to be flaws, regardless of their amplitude response, in accordance with the applicable criteria.

EPRI Report NP-6273, "Accuracy of Ultrasonic Flaw Sizing Techniques for Reactor Vessels", dated March 1989, contains a comparative analysis of sizing accuracy for several different techniques. The results show that the UT flaw sizing techniques based upon tip diffraction are the most accurate. ASME Section XI, Appendix VIII qualified detection and sizing methodologies use analysis tools based upon echo dynamics and tip diffraction. This methodology is considered more sensitive and accurate than amplitude only based comparisons.

For the RPV upper shell-to-flange weld examinations using ASME Section Xl, Appendix VIII, qualified techniques, FPL anticipates obtaining essentially 100% code volume coverage. However, if limitations are encountered that preclude obtaining essentially 100% examination coverage of the required volume, individual relief requests will be submitted.

Procedures, equipment, and personnel qualified via the PDI Appendix VIII, Supplement 4 and 6 programs have been demonstrated to have a high probability of detection and are generally considered superior to the techniques employed during previous ASME Section V, Article 4, reactor vessel weld examinations. Accordingly, approval of this alternative examination and evaluation process is requested pursuant to 10CFR50.55a (a)(3)(i).

L-2012-381 Attachment Page 4 of 5 Turkey Point Units 3 & 4 Fourth Inservice Inspection Interval Relief Request Number 10

6. Duration of Proposed Alternative FPL will implement the proposed alternative Ultrasonic examination of the reactor vessel upper shell-to-flange weld using PDI Demonstrated Techniques during the Turkey Point Units 3 & 4 Fourth Inservice Inspection Interval. The Unit 3 Fourth Inservice Inspection Interval began February 22, 2004 to February 21, 2014 and the Unit 4 Fourth Inservice Inspection Interval began April 15, 2004 to April 14, 2014.

Due to the extended refueling outage for the extended power uprate (EPU) Turkey Point plant modifications, if necessary, FPL may invoke the provision of ASME Section Xl, paragraph IWA-2430 allowing extension of the 4th 10-year interval by 1 year.

Should there be a need, FPL may be performing these proposed reactor vessel upper shell-to-flange weld alternative examinations during the first outage of the fifth 10-year interval, Spring 2014 (Unit 3) and the Fall 2014 (Unit 4) and crediting the examinations to the fourth 10-year inservice inspection interval.

7. Precedents Similar Relief Requests have been granted to the following plants:

0 NRC Safety Evaluation dated October 20, 2004, "Turkey Point Units 3 and 4 -

Safety Evaluation for Relief Request Nos. 34 and 35 Associated with (TAC Nos.

MC3890 and MC3891)."

• NRC Safety Evaluation dated March 23, 2012, "St. Lucie Unit No. 2, Relief from the Requirements of the ASME Code, Relief Request No. 12 (TAC No. ME6745)."

8. Attachments to Relief Request 10

1) Illustration of Reactor Vessel Upper Flange-to-Shell Weld

L-2012-381 Attachment Page 5 of 5 Turkey Point Units 3 & 4 Fourth Inservice Inspection Interval Relief Request Number 10 Illustration of Reactor Vessel Upper Shell-to-Flange Weld

,. *185.0" Dia 17.14" 149.72" Dia Base Metal

149.56" Dia KEYYWAYS e 0*. 90.% 180*, 27.0t 2'.111"'

1.92" Weld Centerline BMT=Base Metal'Thickness

.156" min clad