ML13274A144

NRR E-mail Capture - FW: RAIs for Turkey Point - MF1485/86

ML13274A144
Person / Time
Site:	Turkey Point
Issue date:	09/27/2013
From:	Farideh Saba Plant Licensing Branch II
To:	Hanek O, Tomonto B Florida Power & Light Co
References
MF1485, MF1486
Download: ML13274A144 (4)

Text

NRR-PMDAPEm Resource From: Saba, Farideh Sent: Friday, September 27, 2013 4:06 PM To: Bob.Tomonto@fpl.com; Hanek, Olga (Olga.Hanek@fpl.com); Mihalakea, Stavroula (Stavroula.Mihalakea@fpl.com)

Cc: Klett, Audrey

Subject:

FW: RAIs for Turkey Point - MF1485/86 Importance: High Bob/Olga/Stavy, By letter to the U.S. Nuclear Regulatory Commission (NRC) dated December 14, 2012 (Reference 1), Florida Power & Light Company (FPL, the licensee) submitted its License Renewal Reactor Vessel Internals (RVIs)

Commitment Implementation Report and Inspection Plan that credits the implementation of Materials Reliability Program (MRP)-227-A (Reference 2) at Turkey Point Nuclear Generating Unit Nos. 3 and 4 (i.e., Turkey Point 3 and 4) for NRC staff review. The NRC staff reviewed Revision 0 of MRP-227 and issued a final safety evaluation on December 16, 2011 (Reference 3).

The NRC staff reviewed the information provided by the licensee in its submittal and needs additional information to complete the review. The NRC staffs request for additional information (RAI) is described below. As previously discussed with Ms. Stavroula Mihalakea of your staff, the NRC is requesting a response to the RAIs by October 31, 2013.

REQUEST FOR ADDITIONAL INFORMATION

RAI-1

Appendix A of the MRP-227-A report provides a list of RVI operating experience events that have occurred in Westinghouse, Combustion Engineering, and Babcock and Wilcox pressurized water reactor designs to date.

Describe aging degradation (if any) that occurred thus far in the RVI components of Turkey Point 3 and 4.

RAI-2

Appendix A to MRP-227-A indicates that failures of Alloy X-750 clevis insert bolts were reported by one Westinghouse-designed plant in 2010. Appendix A to MRP-227-A also stated that the most likely cause for failure was bolts cracked due to primary water stress corrosion cracking (PWSCC). Appendix A to MRP-227-A indicates that most of the failures of Alloy X-750 material have occurred in material with heat treatment condition AH (hot rolled equalized at 1625 F followed by 20 hours2.314815e-4 days <br />0.00556 hours <br />3.306878e-5 weeks <br />7.61e-6 months <br /> at 1300 F). Alloy X-750 given the high temperature heat treatment (HTH) has proven more resistant to PWSCC.

The only aging mechanism requiring management by MRP-227-A for clevis insert bolts is wear. The clevis insert bolts are categorized as an Existing Programs component under MRP-227-A, with the American Society of Mechanical Engineers (ASME) Code,Section XI, Inservice Inspection Program credited for managing aging due to wear only. The ASME Code,Section XI specifies a VT-3 visual inspection for the clevis insert bolts, which may not be adequate to detect cracking before it results in bolt failure.

Therefore, discuss if FPL will modify the MRP-227-A inspection requirement for clevis insert bolts to require an inspection that will detect cracking. If the inspection requirement is not modified, provide a technical justification for the adequacy of the existing VT-3 visual inspection requirement to detect cracking before it results in bolt failure.

RAI-3

1

Applicant/Licensee Action Item (A/LAI) 3 of Reference 3 states that the existing aging management program (AMP) for the control rod guide tube (CRGT) split pins shall identify any changes to the program that should be implemented for the period of extended operation. In Reference 1, FPL stated that CRGT split pins were replaced by cold worked type 316 stainless steel material. This replacement would potentially resist stress corrosion cracking (SCC) because the replaced 316 material is more resistant to SCC than the Alloy X-750.

However, Table 3-3 of the MRP-227-A report indicates that these split pins are susceptible to wear and fatigue.

Since the replaced material - type 316 stainless steel - has lower tensile and yield strengths than Alloy X-750 material, it is likely that lower strength type 316 stainless steel material would potentially be susceptible to aging degradation mechanisms due to wear and fatigue.

Describe how FPL will manage the aging degradation due to wear and fatigue of the split pins. Confirm if split pin inspection will be performed under ASME Code,Section XI, Examination Category B-N-3.

RAI-4

a. Identify all RVI components in the Turkey Point 3 and 4 plant design that are defined in the current licensing basis (CLB) as ASME Code,Section XI, Examination Category B-N-3 core support structure components. For these components, identify which of the four inspection categories in MRP-227-A is applicable to the component.

b. If a component identified in the reply to Part (a) is defined as either a Primary Category or Expansion Category component, identify any differences between the inspections that would be performed on the components under MRP-227-A versus the Turkey Point 3 and 4 ASME Code,Section XI inservice inspection program.

c. For the components identified in Part (b), clarify how the differences in inspection bases for these components will be reconciled consistent with the CLB for the facility.

RAI-5

As discussed in Section 3.2.5 of Reference 3, A/LAI 1 requires licensee verification that the detailed component state at the end of the period of extended operation is bounded by the detailed assumptions of the MRP. Please provide the following information related to verification of the applicability of MRP-227-A to Turkey Point 3 and 4:

a. Identify whether the Turkey Point 3 and 4 RVIs include nonweld or bolting austenitic stainless steel components with 20 percent or greater cold work from fabrication and operating surface tensile stresses greater than 30 kilopound force per square inch. Provide a plant-specific evaluation to determine the aging management requirements for the identified components.

b. Identify whether Turkey Point 3 and 4 used an atypical fuel design or fuel management that could make the assumptions of MRP-227-A regarding core loading/core design nonrepresentative for that unit, including those during power changes and uprates. If so, describe how the differences were reconciled with the assumptions of MRP-227-A, or provide a plant-specific AMP for affected components as appropriate.

RAI-6

The staff requests the following clarifications.

a. In response to A/LAI 2 in Reference 1, FPL stated that the flux thimble tube plug was 308SS rather than the 304SS described in MRP-191 (Reference 4). FPL also stated that both alloys are wrought austenitic stainless steel alloys with the same screening criteria for all degradation mechanisms. However, since 308 typically refers to a weld alloy rather than a wrought alloy, clarify whether flux thimble tube plugs are wrought Alloy 308, weld Alloy 308, or another alloy type. If weld alloy is used for the flux thimble tube plugs, describe whether a change to aging management strategy is required.

2

b. In Attachment 1, Table 1 of Reference 1, FPL stated that the upper instrumentation column for Unit 4 was 316SS. However, in response to A/LAI 7 in Reference 1, FPL stated that the upper instrumentation columns and supports for Turkey Point Unit 4 are constructed of cast austenitic stainless steel (CASS).

Clarify whether the upper instrumentation columns are constructed of wrought 316SS or CASS.

REFERENCES

1. Letter from Florida Power & Light, File No. L-2012-438, dated December 14, 2012, Agencywide Documents and Access Management System (ADAMS) Accession No. ML12363A103

2. Electric Power Research Institute (EPRI) Materials Reliability Program Report 1022863 (MRP-227-A),

Pressurized Water Reactor Internals Inspection and Evaluation Guidelines, ADAMS Accession Nos. ML12017A194, ML12017A196, ML12017A197, ML12017A191, ML12017A192, ML12017A195, and ML12017A199

3. Revision 1 to the Final Safety Evaluation of EPRI Materials Reliability Program Report 1016596 (MRP-227), Revision 0, Pressurized Water Reactor Internals Inspection and Evaluation Guidelines, dated December 16, 2011, ADAMS Accession No. ML11308A770

4. EPRI Report 1013234, Materials Reliability Program: Screening, Categorization, and Ranking of Reactor Internals Components for Westinghouse and Combustion Engineering PWR Design (MRP-191), ADAMS Accession No. ML091910130 Please contact Audrey Klett at (301) 415-0489 if you have any questions.

Thanks, Farideh Farideh E. Saba, P.E.

Senior Project Manager NRC/ADRO/NRR/DORL 301-415-1447 Mail Stop O-8G9A Farideh.Saba@NRC.GOV 3

Hearing Identifier: NRR_PMDA Email Number: 858 Mail Envelope Properties (36CF286628C20846A68047F246323309EC42FA76D7)

Subject:

FW: RAIs for Turkey Point - MF1485/86 Sent Date: 9/27/2013 4:05:45 PM Received Date: 9/27/2013 4:05:46 PM From: Saba, Farideh Created By: Farideh.Saba@nrc.gov Recipients:

"Klett, Audrey" <Audrey.Klett@nrc.gov>

Tracking Status: None "Bob.Tomonto@fpl.com" <Bob.Tomonto@fpl.com>

Tracking Status: None "Hanek, Olga (Olga.Hanek@fpl.com)" <Olga.Hanek@fpl.com>

Tracking Status: None "Mihalakea, Stavroula (Stavroula.Mihalakea@fpl.com)" <Stavroula.Mihalakea@fpl.com>

Tracking Status: None Post Office: HQCLSTR02.nrc.gov Files Size Date & Time MESSAGE 8247 9/27/2013 4:05:46 PM Options Priority: High Return Notification: No Reply Requested: No Sensitivity: Normal Expiration Date:

Recipients Received: