ML19213A194

Relief from Impractical American Society of Mechanical Engineers Code Requirements (FNP-ISI-RR-02)

ML19213A194
Person / Time
Site:	Farley
Issue date:	08/08/2019
From:	Markley M Plant Licensing Branch II
To:	Gayheart C Southern Nuclear Operating Co
Williams S
References
EPID L-2018-LLR-0195
Download: ML19213A194 (10)

Text

UNITED STATES NUCLEAR REGULATORY COMMISSION WASHINGTON, D.C. 20555-0001 August 8, 2019 Ms. Cheryl A. Gayheart Regulatory Affairs Director Southern Nuclear Operating Company, Inc.

3535 Colonnade Parkway Birmingham, AL 35243

SUBJECT:

JOSEPH M. FARLEY NUCLEAR PLANT, UNITS 1 AND 2 - RE: RELIEF FROM IMPRACTICAL AMERICAN SOCIETY OF MECHANICAL ENGINEERS CODE REQUIREMENTS (FNP-ISI-RR-02) (EPID L-2018-LLR-0195)

Dear Ms. Gayheart:

By letter dated November 30, 2018, as supplemented by letter dated March 27, 2019, Southern Nuclear Operating Company (SNC, the licensee), requested relief to the inservice inspection (ISi) requirements of the American Society of Mechanical Engineers Boiler and Pressure Vessel Code (ASME Code),Section XI, "Rules for lnservice Inspection (ISi) of Nuclear Power Plant Components," at the Joseph M. Farley Nuclear Plant, Units 1 and 2, for the fourth 10-year ISi interval, that commenced on December 1, 2007, and ended November 30, 2017.

The licensee submitted the request pursuant to Title 10 of the Code of Federal Regulations (10 CFR) Part 50, Section 50.55a(g)(5)(iii), for which the licensee requested relief and to use alternative requirements for ISi items on the basis that the code requirement is impractical.

The U.S. Nuclear Regulatory Commission (NRC) staff reviewed the subject request and has determined, as set forth in the enclosed safety evaluation, that it is impractical for the licensee to comply the ASME Code,Section XI and that complying with the ASME Code requirements would result in undue burden to the licensee. The NRC staff concludes that granting the relief request pursuantto 10 CFR 50.55a(g)(6)(i) is authorized by law and will not endanger life or property or the common defense and security, and is 'otherwise in the public interest giving due consideration to the burden upon the licensee that could result if the requirements were imposed on the facility. The NRC staff concludes reasonable assurance the structural integrity of the subject welds is maintained.

Accordingly, the NRC staff concludes that the licensee has adequately addressed all of the regulatory requirements set forth in 10 CFR 50.55a(g)(6)(i). Therefore, the NRC staff grants the use of relief request FNP-ISI-RR-02 for the fourth 10-year ISi interval that commenced on December 1, 2007, and ended November 30, 2017.

All other ASME Code,Section XI, requirements for which relief has not been specifically requested and approved in this relief request remain applicable, including third-party review by the Authorized Nuclear lnservice Inspector.

C. Gayheart If you have any questions, please contact the Senior Project Manager, Shawn Williams, at 301-415-1009 or by email at Shawn.Williams@nrc.gov.

Sincerely, Michael T. Markley, Chief Plant Licensing Branch 11-1 Division of Operating Reactor Licensing Office of Nuclear Reactor Regulation Docket Nos. 50-348 and 50-364

Enclosure:

Safety Evaluation cc: Listserv

UNITED STATES NUCLEAR REGULATORY COMMISSION WASHINGTON, D.C. 20555-0001 SAFETY EVALUATION BY THE OFFICE OF NUCLEAR REACTOR REGULATION PROPOSED ALTERNATIVE FOR THE FOURTH INTERVAL INSERVICE INSPECTION FNP-ISI-RR-02. VERSION 1.0 SOUTHERN NUCLEAR OPERATING COMPANY. INC.

JOSEPH M. FARLEY NUCLEAR PLANT. UNITS 1 AND 2 DOCKET NOS. 50-348 AND 50-364

1.0 INTRODUCTION

By letter dated November 30, 2018 (Agencywide Documents Access and Management System (ADAMS) Accession No. ML18334A032), as supplemented by letter dated March 27, 2019 (ADAMS Accession No. ML19086A215), Southern Nuclear Operating Company (SNC, the licensee), requested relief to the inservice inspection (ISi) requirements of the American Society of Mechanical Engineers Boiler and Pressure Vessel Code (ASME Code),Section XI, "Rules for lnservice Inspection (ISi) of Nuclear Power Plant Components," at the Joseph M. Farley Nuclear Plant, Units 1 and 2, for the fourth 10-year ISi interval that commenced on December 1, 2007, and ended November 30, 2017.

The licensee submitted the request pursuant to Title 10 of the Code of Federal Regulations (1 O CFR) Part 50, Section 50.55a(g)(5)(iii), for which the licensee requested relief and to use alternative requirements for ISi items on the basis that the code requirement is impractical.

2.0 REGULATORY EVALUATION

Paragraph 10 CFR 50.55a(g)( 4 ), lnservice inspection standards requirement for operating plants, states, in part:

Throughout the service life of a boiling or pressurized water-cooled nuclear power facility, components (including supports) that are classified as ASME Code Class 1, Class 2, and Class 3 must meet the requirements, except design and access provisions and preservice examination requirements, set forth in Section XI, ... to the extent practical within the limitations of design, geometry, and materials of construction of the components ....

Enclosure

The regulation in 10 CFR 50.55a(g)(5)(iii), states that:

If the licensee has determined that conformance with a Code requirement is impractical for its facility, the licensee must notify the NRC and submit, as specified in Section 50.4, information to support the determinations.

Determinations of impracticality in accordance with this section must be based on the demonstrated limitations experienced when attempting to comply with the Code requirements during the inservice inspection interval for which the request is being submitted. Requests for relief made in accordance with this section must be submitted to the NRC no later than 12 months after the expiration of the initial or subsequent 120-month inspection interval for which relief is sought.

The regulation at 10 CFR 50.55a(g)(6)(i), states that:

The Commission will evaluate determinations under paragraph (g)(S) of this section that code requirements are impractical. The Commission may grant such relief and may impose such alternative requirements as it determines are authorized by law, will not endanger life or property or the common defense and security, and are otherwise in the public interest giving due consideration to the burden upon the licensee that could result if the requirements were imposed on the facility.

Based on the above, and subject to the following technical evaluation, the NRC staff finds that regulatory authority exists for the licensee to request and the NRC staff to grant the relief requested by the licensee.

3.0 TECHNICAL EVALUATION

3.1 The Licensee's Request for Relief 3.1.1 ASME Code Component(s) Affected The affected components are ASME Code Class 1 piping welds. They are listed in Tables RR-02.1 and RR-02.2 of the relief request and are summarized below. These welds are examined in accordance with Examination Category 8-D, Item 83.110, in Table IWB-2500-1 of the ASME Code,Section XI.

Examination Category 8-D is related to the full penetration welded nozzles in vessels.

Specifically, Item 83.110, applies to the nozzle-to-vessel welds at pressurizer (PZR).

Farley Unit 1 Component ID System Exam Exam Outage Diameter/

Requirement Category Exam thickness ALA1-2100-9 PZR upper head to IWB-2500-?(b) 8-D 1R22 6"/3.88" safety nozzle weld volumetric (UT) 83.110 (831)

ALA 1-2100-10 PZR upper head to IWB-2500-?(b) 8-D 1R27 6"/3.88" safety nozzle weld Volumetric (UT) 83.110 (831)

ALA 1-2100-11 PZR upper head to IW8-2500-7(b) 8-D , 1R24 6"/3.88" safety nozzle weld Volumetric (UT} 83.110 (831)

ALA 1-2100-12 PZR upper head to IW8-2500-7(b) 8-D 1R24 4"/3.88" spray nozzle weld Volumetric (UT) 83.110 (831)

ALA 1-2100-13 PZR upper head to IW8-2500-7 (b) 8-D 1R24 6"/3.88" PORV nozzle weld . Volumetric (UT) 83.110 (831)

ALA1-2100-14 PZR lower head to IW8-2500-7(b) 8-D 1R24 14"/3.88" surge nozzle weld Volumetric (UT) 83.110 (831)

Farley Unit 2 Component ID System Exam Exam Outage Diameter/

Requirement Category Exam thickness APR 1-21 00-9 PZR upper head to IW8-2500-7(b} 8-D 2R23 6"/3.88" safety nozzle weld volumetric (UT} 83.110 (831)

APR1-2100-10 PZR upper head to IW8-2500-7(b) 8-D 2R23 6"/3.88" safety nozzle weld Volumetric (UT) 83.110 (831)

APR1-2100-11 PZR upper head to IW8-2500-7(b) 8-D 2R24 6"/3.88" safety nozzle weld Volumetric (UT) 83.110 (831)

APR1-2100-12 PZR upper head to IW8-2500-7(b) 8-D 2R24 4"/3.88" spray nozzle weld Volumetric (UT) 83.110 (831)

APR1-2100-13 PZR upper head to IW8-2500-7(b) 8-D 2R19 6"/3.88" PORV nozzle weld Volumetric (UT) 83.110 (831)

APR1-2100-14 PZR lower head to IW8-2500-7(b) 8-D 2R19 14"/3.88" surge nozzle weld Volumetric (UT) 83.110 (831) 3.1.2 Applicable Code Edition and Addenda The Code of record for the fourth 10-year ISi Program interval is the ASME Code,Section XI, 2001 Edition through the 2003 Addenda.

In its letter dated March 27, 2019, the licensee stated that it performed the required examination in accordance with the requirements of ASME,Section V, Article 4. In the case of limited examinations, efforts were made to obtain additional examination coverage.

3.1.3 Applicable Code Requirements The licensee stated:

The extent of examination requirement for Examination Category B-D, Item Number 83.110, per Table IWB-2500-1, requires a volumetric examination of essentially 100% of the weld length.

By email dated February 25, 2019 (ADAMS Accession No. ML19056A214), the NRC staff requested additional information (RAI 4) to clarify whether Table IWB-2500-1 requires a volumetric examination of 100 percent, not essentially 100 percent, coverage of the weld length.

The NRC staff noted that the essentially 100 percent examination coverage is permitted only by ASME Code Case N-460, "Alternative Examination Coverage for Class 1 and Class 2 Welds,Section XI, Division 1." In its letter dated March 27, 2019, the licensee stated, "The extent of examination requirement for Examination Category B-D, Item Number 83.110, per Table IWB-2500-1 and in accordance with NRC approved ASME Code Case N-460, requires a volumetric examination of essentially 100% of the weld length."

3.1.4 Impracticality of Compliance The licensee stated:

Pursuant to 10 CFR50.55a(g)(5)(iii), relief is requested on the basis that conformance with these code requirements is impractical since conformance would require extensive structural modifications to the component or surrounding structure.

Due to the original design of these components, it is not feasible to effectively perform the examinations to the extent required for welds and welded attachments (greater than 90% of the volume or area) due to physical obstructions, plant location, and/or component geometry.

FNP is unable to satisfy the ASME Section XI Code requirements to perform a surface or volumetric examination of these components due to the physical component configuration, interference from permanent plant equipment, single-sided access, etc.

FNP would incur significant engineering, material, and installation costs to perform such modifications without a compensating increase in the level of quality and safety.

Therefore, relief is requested on the basis that the ASME Section XI Code requirements to examine these components are impractical.

Tables RR-02.1 and RR-02.2 provide a summary of the examination limitations for each component for which relief is requested. The tables also indicate the outage the component was examined, the coverage percentage obtained for each component, and other pertinent design information. These tables are the cumulative lists of the limited ASME Section XI examinations performed during the Fourth ISi Interval. Figures 2-1 through 2-9 provide typical configuration and coverage plots that detail the examination limitations. The shaded areas in the figures show where at least one scan angle is achieved.

All the welds in the referenced tables, receive an inner radius examination with 100%

coverage. No recordable indications have documented on any of these components with the examinations performed during the 4th interval. In reviewing the SNC fleet

operating experience, (Vogtle Units 1 and 2 and Farley Units 1 and 2) no leakage or indications that require flaw evaluations or repairs have been found from the Category B-D, Item No. B3.110.

Based on the above explanation, SNC requests relief to perform examinations without achieving ASME Section XI Code compliance coverage when the required coverage is impractical.

3.1.5 Proposed Alternative and Basis for Use The licensee stated:

FNP has performed the ASME Section XI Code required examinations to the maximum extent practical (Code Coverage), which are documented in Tables RR-02.1 and RR-02.2. Due to the physical interferences causing these limitations, there are no alternative examination techniques currently available to increase coverage.

3.1.6 Duration of Proposed Alternative The proposed alternative is applicable for the fourth 10-year ISi interval that commenced on December 1, 2007, and ended November 30, 2017.

3.2 NRC Staff Evaluation The NRC staff verified the licensee proposed percentages of examination coverage and impracticality to achieve the required coverage, applicable Code ISi requirements, and potential degradation mechanisms of the welds. The NRC staff determined that structural integrity of these welds can be ensured, even though the licensee could not achieve the required essentially 100 percent examination coverage for all subject welds. The NRC staff also notes that ASME Code Case N-460 permits examination coverage of less than 100 percent but greater than 90 percent to satisfy the 100 percent examination coverage requirement of Table IWB-2500-1 of the ASME Code,Section XI.

For the ultrasonic testing (UT) examination of the subject welds, the licensee used a zero-degree longitudinal wave, and 45- and 60-degree shear waves. The transducers are at a frequency of 2.25 megahertz. For the subject welds, the NRC staff notes that examination of Category B-D, Item No. B3.110, component in accordance with the ASME Code,Section XI, is specified in Figure IWB-2500-7(a) through (d). Figure IWB-2500-7 not only specifies the examination of the pipe-to-nozzle welds at the PZR but also the inner radius of the nozzle itself.

The NRC staff has reviewed the diagrams of sonification of the UT beams in the examination of the subject welds and confirmed the licensee's examination coverage as follows:

Unit 1 The licensee obtained 75 percent examination coverage for the PZR upper head to safety nozzle weld, ALA1-2100-9, as shown on Figures 2-1 and 2-3 of the relief request. Based on the sonification diagram in Figure 2-3, the NRC staff confirmed the licensee's examination coverage calculation of this weld.

The licensee obtained 78.6 percent examination coverage for the following PZR welds:

ALA1-2100-10, ALA1-2100-11, ALA1-2100-12, and ALA1-2100-13 as shown in Figures 2-1 and 2-4. Based on the sonification diagram in Figure 2-4 of the relief request, the NRC staff confirmed the licensee's examination coverage calculations of these welds.

The licensee obtained 75 percent examination coverage for the PZR lower head to surge nozzle weld, ALA1-2100-14, as shown in Figures 2-2 and 2-5 of the relief request. Based on the sonification diagram in Figure 2-5, the NRC staff confirmed the licensee's examination coverage calculation of this weld.

Unit 2 The licensee obtained 61.1 percent examination coverage for two PZR upper head to safety nozzle welds, APR1-2100-9, and APR1-2100-10, as shown in Figures 2-1 and 2-6 of the relief request. Based on the sonification diagram in Figure 2-6, the NRC staff confirmed the licensee's examination coverage of these two welds.

The licensee obtained 50 percent examination coverage for the PZR upper head to safety nozzle weld, APR1-2100-11, and PZR upper head to spray nozzle weld, APR1-2100-12, as shown in Figures 2-1 and 2-7 of the relief request. Based on the sonification diagram in Figure 2-7, the NRC staff confirmed the licensee's examination coverage calculation of these two welds.

The licensee obtained 75 percent examination coverage for the PZR upper head to power-operated relief valve nozzle weld, APR1-2100-13, as shown in Figures 2-1 and 2-8 of the relief request. Based on the sonification diagram in Figure 2-8, the NRC staff confirmed the licensee's examination coverage calculation of this weld.

The licensee obtained 61 percent examination coverage for the PZR lower head to surge nozzle weld, APR1-2100-14, as shown in Figures 2-2 and 2-9 of the relief request. Based on the sonification diagram in Figure 2-9, the NRC staff confirmed the licensee's examination coverage calculation of this weld.

Based on licensee's diagrams of UT sonification and the configuration of the welds and associated PZR nozzles, the NRC staff confirmed that it is impractical to achieve essentially 100 percent examination coverage of the subject welds. The NRC staff finds that to achieve essentially 100 percentage examination coverage, the licensee would need to modify the location of the welds in addition to other structure modification which would result in undue burden on the licensee.

The NRC staff finds that, in addition to the above examination, the licensee also examined the inner radius of each nozzle with UT and magnetic particle testing. The licensee achieved 100 percent coverage in the nozzle inner radius examination and did not identify any indications.

The NRC staff determines that the nozzle inner radius examination satisfies the requirement in accordance with Figure IWB-2500-7 of the ASME Code,Section XI.

In the March 27, 2019, supplement, the licensee indicated that the filler metal used in the subject welds is not stainless steel or nickel-based Alloy 82/182. The NRC staff notes that if the weld filler metal were stainless steel or Alloy 82/182, there would be additional regulatory limitations. However, the licensee indicated that the filler metal used in the subject welds was

low alloy steel, SFA 5.5 Type E 9018-M for manual welding and SFA 5.17 Type EH 14 for automated welding. The NRC staff finds that there are no additional regulatory constraints associated with the low alloy steel filler metal other than those that the licensee has addressed in the relief request.

Compensatory Measures In RAI 2, the NRC staff asked the licensee to discuss other measures that could monitor structural integrity of the subject welds, given that certain volumes of the subject welds could not be examined. In its response, the licensee stated that it performed the Class 1 pressure testing per IWB-5000 during startup from refueling outages. A VT-2 examination of the PZR cubicle is performed every outage in conjunction with the performance of the reactor coolant system (RCS) leak test. The licensee also stated that, in accordance with the boric acid corrosion control program, it performs boric acid walkdowns inside containment early in the refueling outage to identify potential leakage areas. The licensee also performs online monitoring and trending on the identified and unidentified leakage in the RCS system per Technical Specification Surveillance Requirement 3.4.13.1. The NRC staff finds that: ( 1) the boric acid corrosion control program, (2) the online monitoring and trending system, and (3) the system leakage test per the ASME Code,Section XI, IWB-5000, is sufficient to detect any potential leakage from the subject welds. Therefore, the NRC concludes that these measures provide adequate assurance to demonstrate structural integrity of the subject welds.

In summary, the NRC staff finds acceptable that the licensee has examined the subject welds to the maximum extent possible and that there are no indications detected in the subject welds.

For the weld volumes that could not be examined, the licensee has implemented measures to monitor the subject welds. The NRC staff finds that the licensee has demonstrated reasonable assurance structural integrity of the subject welds.

4.0 CONCLUSION

As set forth above, the NRC staff concludes that it is impractical to comply with the ASME Code,Section XI. The NRC staff concludes at imposition of the ASME Code requirements would result in a burden to the licensee. The NRC staff concludes that granting the relief request pursuant to 10 CFR 50.55a(g)(6)(i) is authorized by law and will not endanger life or property or the common defense and security, and is otherwise in the public interest giving due consideration to the burden upon the licensee that could result if the requirements were imposed on the facility. The NRC staff concludes reasonable assurance the structural integrity of the subject welds is maintained.

Accordingly, the NRC staff concludes that the licensee has adequately addressed all of the regulatory requirements set forth in 10 CFR 50.55a(g)(6)(i). Therefore, the NRG staff grants the use of relief request FNP-ISI-RR-02 for the fourth 10-year ISi interval that commenced on December 1, 2007, and ended November 30, 2017.

All other ASME Code,Section XI, requirements for which, relief has not been specifically requested and approved in this relief request remain applicable, including third-party review by the Authorized Nuclear lnservice Inspector.

Principal Contributor: John Tsao, NRR Date of issuance: August 8, 2019

ML19213A194 OFFICE NRR/DORL/LPLI 1-1 /PM NRR/DORL/LPLII 1/LA NRR/DMLR/MPHB/ABC NAME SWilliams KGoldstein (Rohrer for) ABuford DATE 8/01/2019 8/07/19 7/11/2019 OFFICE NRR/DORL/LPLII 1/BC NRR/DORL/LPLII 1/PM NAME MMarkley SWilliams DATE 8/08/19 8/08/19 (Jlamb for)