L-2025-025, Units 3 and 4 - Response to Requests for Additional Information Regarding Turkey Point Fifth and Sixth 10-Year Inservice Testing Interval Relief Request No. VR-02
| ML25038A069 | |
| Person / Time | |
|---|---|
| Site: | Turkey Point  |
| Issue date: | 02/07/2025 |
| From: | Mack K Florida Power & Light Co |
| To: | Office of Nuclear Reactor Regulation, Document Control Desk |
| References | |
| L-2025-025, EPID L-2024-LLE-0059 | |
| Download: ML25038A069 (1) | |
Text
l=PL.
U. S. Nuclear Regulatory Commission Attn: Document Control Desk Washington DC 20555-0001 RE:
Turkey Point Nuclear Plant, Unit 3 and 4 Docket Nos. 50-250 and 50-251 Subsequent Renewed Facility Operating Licenses DPR-31 and DPR-41 February 7, 2025 L-2025-025 10 CFR 50.55a Response to Requests for Additional Information Regarding Turkey Point Fifth and Sixth 10-Year lnservice Testing Interval Relief Request No. VR-02 References:
- 1.
Florida Power & Light Company letter L-2024-106, Fifth and Sixth 10-Year lnservice Testing Interval Relief Request No. VR-02, August 12, 2024 (ADAMS Accession No. ML24225A100)
- 2.
Nuclear Regulatory Commission electronic memorandum dated January 13, 2025, Request for Additional Information Related to Turkey Point Nuclear Plant Relief Request VR MOVs biennial leakage test requirement (EPID L-2024-LLE-0059) (ADAMS Accession No. ML25013A301)
In Reference 1, Florida Power & Light Company (FPL) proposed an alternative to the American Society of Mechanical Engineers Boiler and Pressure Vessel Code, Operation and Maintenance of Nuclear Power Plants (ASME OM Code) requirements for Turkey Point Nuclear Plant, Units 3 and 4 (Turkey Point).
Specifically, relief from the ASME OM Code, Section ISTC-3630, biennial leakage testing requirements was requested for Turkey Point motor-operated isolation valves, MOV-864NB, located on the Refueling Water Storage Tank (RWST) outlet lines, and MOV-856NB, located on the RWST return lines, on the basis that the proposed alternative would provide an acceptable level of quality and safety.
In Reference 2, the NRG staff requested additional information deemed necessary to complete its review.
The enclosure to this letter provides FPL's response to the NRG requests for additional information (RAls).
In addition, FPL requests a change to the "blue check" inspection frequency proposed in Reference 1 for valves MOV-864NB and MOV-856NB. Specifically, FPL now proposes a frequency of once every 8-years in lieu of once every 6-years. The 8-year frequency serves to align the inspections with the Turkey Point transition to 24-month fuel cycles, which begins this Unit 4 spring 2025 refueling outage, while continuing to subject each MOV to a "blue check" every four refueling outages as proposed in Reference 1 originally.
The information in this RAI response provides additional information that clarifies the application and does not expand the scope of the application.
This letter contains no new or modified regulatory commitments.
Should you have any questions regarding this submission, please contact Ms. Maribel Valdez, Fleet Licensing Manager, at 561-904-5164.
Sincerely,
~~
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_ /
KennAM Director, Licensing and Regulatory Compliance Florida Power & Light Company Florida Power & Light Company 9760 SW 344th Street, Homestead, FL 33035
Turkey Point Nuclear Plant Docket Nos. 50-250 and 50-251 cc:
USNRC Regional Administrator, Region II USN RC Project Manager, Turkey Point Nuclear Generating Station USN RC Senior Resident Inspector, Turkey Point Nuclear Generating Station Mr. Clark Eldredge, Florida Department of Health
Enclosure:
L-2025-025 Page 2 of 2
Turkey Point Nuclear Plant Docket Nos. 50-250 and 50-251 Response to Request for Additional Information (RAI)
Turkey Point MOV Alternative VR-02 for 5th and 6th 1ST Program Intervals L-2025-025 Enclosure Page 1 of 8 In Reference 1, Florida Power & Light Company (FPL) proposed an alternative to the American Society of Mechanical Engineers Boiler and Pressure Vessel Code, Operation and Maintenance of Nuclear Power Plants (ASME OM Code) requirements for Turkey Point Nuclear Plant, Units 3 and 4 (Turkey Point).
Specifically, relief from the ASME OM Code, Section ISTC-3630, biennial leakage test requirements was requested for Turkey Point motor-operated isolation valves, MOV-864A/B, located on the Refueling Water Storage Tank (RWST) outlet lines, and MOV-856A/B, located on the RWST return lines, on the basis that the proposed alternative would provide an acceptable level of quality and safety.
In Reference 2, the NRC Mechanical Engineering and lnservice Testing Branch (EMIB) requested additional information deemed necessary to complete its review, as indicated below. FPL's response to the requests for additional information (RAls) follows.
Question 1 (EMIB-RAI-VR-02-01)
Alternative Request VR-02 relies on the past performance of the four MOVs in each Turkey Point unit to support the use of periodic internal inspections rather than 2-year leak testing required by the ASME OM Code. The licensee is requested to describe the performance of recent 1ST tests (exercise, stroke time, and diagnostic testing) for these MOVs, and the test results.
FPL Response:
Motor-operated valves MOV-*-856A/B and MOV-*-864A/B are normally open during plant operation to support the standby operational status of the safety injection and containment spray systems for postulated accident response. The systems are aligned to support the initial refueling water storage tank (RWST) injection phase of the design basis loss of reactor coolant accident. The four MOVs are subsequently closed to isolate the RWST when its contents have been injected to the containment building to support the long-term containment recirculation mode of operation.
The Turkey Point Unit 3 and 4 1ST Program requires stroke time testing of these MOVs from the open to the closed position and verification of proper remote position indication. This testing is performed during cold shutdown conditions and is typically performed during refueling outages. The stroke time test is conducted using a calibrated stopwatch to measure the length of time that it takes for the control room open indication to change to a closed indication during valve operation. The position indication tests are performed using an observer stationed locally at the valve and in communication with another observer located at the remote position indicator. As the valve is operated, actual valve position is compared to that indicated at the remote location.
The results of the stroke time and position indication tests for the past five refueling outages are tabulated below in Tables 1-1 through 1-4. Satisfactory test results were obtained during each test.
Table 1-1 MOV-3-856A/B 1ST Test History MOV-3-856A MOV-3-856A MOV-3-856A MOV-3-856B MOV-3-856B MOV-3-856B Test Stroke Time Stroke Time Position Stroke Time Stroke Time Position Date Acceptable Range Measurement Indication Acceptable Range Measurement Indication (Sec)
(Sec)
(Sat/UnSat)
(Sec)
(Sec)
(Sat/Un sat)
PT3-30 12.98 to 17.54 15.56 Sat 13.88 to 18.76 15.56 Sat PT3-31 12.98 to 17.54 14.31 Sat 13.88 to 18.76 16.77 Sat PT3-32 12.98to 17.54 14.32 Sat 13.88to 18.76 16.87 Sat PT3-33 12.17 to 16.46 14.31 Sat 13.88 to 18.76 16.59 Sat PT3-34 12.17to 16.46 15.52 Sat 13.88 to 18.76 15.03 Sat
Turkey Point Nuclear Plant Docket Nos. 50-250 and 50-251 MOV-3-864A Test Stroke Time Table 1-2 MOV-3-864A/B 1ST Test History MOV-3-864A MOV-3-864A MOV-3-8648 Stroke Time Position Stroke Time Date Acceptable Range Measurement Indication Acceptable Range (Sec)
(Sec)
(Sat/Un Sat)
(Sec)
PT3-30 36.46 to 49.32 43.82 Sat 36.24 to 49.02 PT3-31 36.46 to 49.32 43.54 Sat 36.24 to 49.02 PT3-32 36.46 to 49.32 43.15 Sat 36.24 to 49.02 PT3-33 36.46 to 49.32 43.14 Sat 36.24 to 49.02 PT3-34 36.46 to 49.32 43.23 Sat 36.24 to 49.02 Table 1-3 MOV-4-856A/B 1ST Test History MOV-4-856A MOV-4-856A MOV-4-856A MOV-4-8568 Test Stroke Time Stroke Time Position Stroke Time Date Acceptable Range Measurement Indication Acceptable Range (Sec)
(Sec)
(Sat/Unsat)
(Sec)
PT4-30 13.45 to 18.19 15.93 Sat 13.26 to 17.93 PT4-31 13.45 to 18.19 15.85 Sat 13.26 to 17.93 PT4-32 13.45 to 18.19 15.90 Sat 13.26 to 17.93 PT4-33 13.45to 18.19 16.03 Sat 13.26 to 17.93 PT4-34 13.45 to 18.19 15.90 Sat 13.26 to 17.93 Table 1-4 MOV-4-864A/B 1ST Test History MOV-4-864A MOV MOV-4-864A MOV-4-8648 Test Stroke Time 864A Position Stroke Time Date Acceptable Range Stroke Time Indication Acceptable Range (Sec)
(Sec)
(Sat/Unsat)
(Sec)
PT4-30 39.76 to 53.78 44.42 Sat 37.34 to 50.50 PT4-31 39.76 to 53.78 44.58 Sat 37.34 to 50.50 PT4-32 39.76 to 53.78 44.40 Sat 37.34 to 50.50 PT4-33
- 39. 76 to 53. 78 44.79 Sat 37.34 to 50.50 PT4-34 39.76 to 53.78 44.53 Sat 37.34 to 50.50 MOV-3-8648 Stroke Time L-2025-025 Enclosure Page 2 of 8 MOV-3-8648 Position Measurement Indication (Sec)
(Sat/UnSat) 46.93 Sat 42.85 Sat 42.67 Sat 42.50 Sat 42.42 Sat MOV-4-8568 MOV-4-8568 Stroke Time Position Measurement Indication (Sec)
(Sat/Un sat) 15.51 Sat 15.77 Sat 15.74 Sat 15.58 Sat 15.61 Sat MOV-4-8648 MOV-4-8648 Stroke Time Position Measurement Indication (Sec)
(Sat/Un sat) 43.73 Sat 47.48 Sat 44.03 Sat 43.87 Sat 43.99 Sat Turkey Point Units 3 and 4 are nearing the end of the fifth 10-year 1ST interval and currently comply with the 2004 Edition of the ASME Operations and Maintenance (OM) Code. The sixth 10-year 1ST interval will start on February 22, 2025, for Unit 3 and April 15, 2025, for Unit 4. The sixth 10-year 1ST interval will comply with the 2020 Edition of the Code except where relief from such requirements has been granted in writing by the NRC. The 2020 Edition of the ASME OM Code will no longer require stroke time testing of the subject MOVs. Diagnostic testing will be used to ensure proper operation of the MOVs in accordance with their design basis conditions.
Diagnostic testing of these MOVs is currently performed in accordance with the Turkey Point Units 3 and 4 MOV program. The MOV program complies with NRC Generic Letters (GL) 89-10 and 96-05.
Diagnostic testing of the subject MOVs has been performed on a six refueling outage frequency. With the current 18-month operating cycle, this is equivalent to once every nine years. This frequency is within the 10-year test frequency specified for these valves by the MOV Joint Owners Group (JOG).
Turkey Point Units 3 and 4 are in the process of transitioning to a 24-month operating cycle. This will
Turkey Point Nuclear Plant Docket Nos. 50-250 and 50-251 L-2025-025 Enclosure Page 3 of 8 result in a change in the diagnostic testing to a four refueling outage frequency which is equivalent to once every eight years.
Diagnostic testing of the subject MOVs is performed periodically to confirm proper mechanical and electrical operation of the valves and motor operators in accordance with Turkey Point commitments to GL 96-05. The testing intervals have been established using the Joint Owners Group (JOG) MOV Periodic Verification methodology which considers the probabilistic risk assessment (PRA) ranking and the available margin of the MOV. Diagnostic testing is also performed after actuator overhaul and any maintenance that could affect the required thrust or capability of the MOV.
The current maintenance practice includes a detailed pre-test inspection of the actuator condition prior the periodic diagnostic test. This includes inspection of the limit switch compartment, heater (if used), finger bases, rotors, torque switch contacts, wires and wire terminations, motor mounting fasteners, conduit, internal brushes, and all gasket surfaces. The condition of the motor connections are also assessed via a megger check. The exposed valve parts are re-lubricated, and the actuator gearbox grease is sampled to check for water intrusion, dirt, hardening, and foreign particles. The diagnostic testing is currently performed using the Crane-Nuclear VOTES Infinity system. This system is widely used in the nuclear industry for MOV testing.
Tables 1-5 and 1-6 provide the recent test history of the Unit 3 and 4 valves.
Table 1-5 Unit 3 MOV Diagnostic Test Results Test Date MOV-3-856A MOV-3-8568 MOV-3-864A MOV-3-8648 PT3-34 Complete PT3-33 PT3-32 PT3-31 Complete Complete PT3-30 PT3-29 Complete PT3-28 PT3-27 PT3-26 Complete Complete PT3-25 Complete Complete Table 1-6 Unit4 MOV Diagnostic Test Results Test Date MOV-4-856A MOV-4-8568 MOV-4-864A MOV-4-8648 PT4-34 PT4-33 PT4-32 Complete Complete Complete PT4-31 PT4-30 PT4-29 Complete PT4-28 Complete PT4-27 PT4-26 Complete Complete Complete PT4-25 As documented above, the subject MOVs have been inspected and tested as required in the Turkey Point Units 3 and 4 1ST and MOV programs. The results have been satisfactory and demonstrate that the subject MOVs have been maintained in a condition that supports their design basis function.
Turkey Point Nuclear Plant Docket Nos. 50-250 and 50-251 Question 2 (EMIB-RAI-VR-02-02)
L-2025-025 Enclosure Page 4 of 8 Alternative Request VR-02 proposes to rely on the close capability of the MOV-856NB 2-inch globe valves and MOV-864NB 16-inch double-disk valves in each Turkey Point unit to achieve the leak tightness required for these valves. The licensee is requested to describe the diagnostic testing of the MOV-856NB 2-inch globe valves and MOV-864NB 16-inch double-disk valves (including torque or limit switch controls) to demonstrate the effectiveness of the diagnostic testing to provide sufficient closing thrust and torque to minimize seat leakage, and to avoid damage to the valve and actuator.
FPL Response:
MOV-856NB, HHSI Pump Recirc to RWST MOV These 2-inch Copes-Vulcan unbalanced globe MOVs are controlled by the torque switch in the close direction. The Votes Infinity system is used to acquire, save, and analyze the diagnostic test data.
Thrust is measured by use of a Crane-Nuclear nuC' stem force sensor. Torque is measured by use of spring pack displacement (SPD) correlated to Torque Thrust Cell (TTC) torque from a previous test for each valve.
Sufficient closing thrust:
For setup of the Unit 3 MOVs in the Fall 2024 refueling outage, an additional Class V sealing load was added to the design minimum required thrust to determine a design minimum available thrust (seat load) value to achieve a Class V sealing load. A Class V sealing load or leakage rate is defined by ANSI/FCI 70 2006, Control Valve Seat Leakage, as 0.0005 ml/minute of water per inch of port diameter per psi differential and is the most limiting leakage class. The Class V sealing load value was increased to account for thrust measurement uncertainty and torque switch repeatability to establish a minimum available thrust (C14 - C11) acceptance criteria for testing. Note that the results of the most recent DP tests for all four MOVs showed O or negative rate-of-loading (ROL) effect.
Therefore, a ROL adjustment factor of O is applied to these MOVs. The Class V sealing load value was calculated based on the method used by Copes-Vulcan at a DP of 1711 psid (HHSI pump shutoff head+ RHR pump shutoff head+ maximum containment pressure).
The measured available thrust (C14 - C11) is verified to be greater than the test acceptance criteria value. This ensures the MOVs are capable of closing against the design basis DP and generating the Class V sealing load.
The same approach will be applied on the Unit 4 MOVs in the Spring 2025 refueling outage and future MOV diagnostic tests.
Avoid damage to the valve and actuator:
The close torque at CST (C14) and total torque (C16) test acceptance criteria in terms of SPD are the SMB-000 torque rating reduced to account for torque measurement uncertainty, torque switch repeatability, and spring pack correlation uncertainty. This is less than the degraded voltage operator output torque capability for these MOVs. The measured C14 and C16 SPD values are verified to be less than the test acceptance criteria value ensuring the motor-operator degraded voltage capability and torque rating are not exceeded.
The close total thrust (C16) test acceptance criteria is the valve weak link reduced to account for thrust measurement uncertainty and torque switch repeatability. This is less than 140% SMB-000 extended thrust rating. The measured C16 thrust value is verified to be less than the test acceptance criteria value ensuring the motor-operator thrust and valve weak link ratings are not exceeded.
Turkey Point Nuclear Plant Docket Nos. 50-250 and 50-251 L-2025-025 Enclosure Page 5 of 8 Note that the motor-operator mounting bolts have been changed to high strength socket head cap screws, housing covers verified to be the "new" design, and seismic declutch levers installed on all four MOVs to enable use of 140% SMB-000 extended thrust rating per Limitorque Technical Update 92-01.
Post-test evaluation A post-test evaluation including assessment of as-left MOV functional margin is performed per of O-ADM-540.
MOV-864NB, RWST to SI & RHR Pumps Isolation MOV These 16x14x16 inch Anchor/Darling double disk gate MOVs are also controlled by the torque switch in the close direction. The Votes Infinity system is used to acquire, save, and analyze the diagnostic test data. Thrust is measured by use of a Crane-Nuclear stem calibrator (C-Clamp). Torque is measured by use of spring pack displacement correlated to TTC torque from a previous test for each valve.
Closing thrust to minimize seat leakage:
The minimum required thrust for these MOVs is determined by use of the EPRI PPM for Anchor/Darling Double Disk Gate Valves. The disks' hard seated condition is used assuming worst case orientation of the upper and lower wedge. This value was increased to account for ROL effects, thrust measurement uncertainty, and torque switch repeatability to establish a minimum available thrust (C14 - C11) acceptance criteria for testing. The measured available thrust or seat load (C14 -
C 11) is verified to be greater than the test acceptance criteria value.
Note that application of the ROL adjustment factor on these MOVs is conservative since there is no flow during switchover from injection to the recirculation phase when the valves are closed under design basis conditions.
To avoid damage to the valve and actuator The close torque at CST (C14) test acceptance criteria in terms of SPD is the degraded voltage operator output torque capability reduced to account for torque measurement uncertainty, torque switch repeatability, and spring pack correlation uncertainty. The measured C14 SPD value is verified to be less than the test acceptance criteria value ensuring the torque switch will trip prior to exceeding the degraded voltage operator output torque capability.
The close total torque (C16) test acceptance criteria in terms of SPD is the SMB-0 torque rating reduced to account for torque measurement uncertainty, torque switch repeatability, and spring pack correlation uncertainty. The measured C16 SPD value is verified to be less than the test acceptance criteria value ensuring the motor-operator torque rating is not exceeded.
The close total thrust (C16) test acceptance criteria is 140% SMB-0 extended thrust rating per Limitorque Technical Update 92-01 reduced to account for thrust measurement uncertainty and torque switch repeatability. This is less than the valve weak link. The measured C16 thrust value is verified to be less than the test acceptance criteria value ensuring the motor-operator thrust and valve weak link ratings are not exceeded.
Post-test evaluation A post-test evaluation including assessment of as-left MOV functional margin is performed by qualified program engineers. This includes a review of the data signatures recorded during the test for thrust, torque, spring pack displacement, motor current, and switch trip and drop-out time
Turkey Point Nuclear Plant Docket Nos. 50-250 and 50-251 L-2025-025 Enclosure Page 6 of 8 measurements. Comparison of the diagnostic test data with data previously taken is also performed to determine if any negative trends exist.
Question 3 (EMIB-RAI-VR-02-03)
Alternative Request VR-02 proposes periodic internal inspections rather than leak testing to assess the operational readiness of the applicable valves to perform their leak-tight safety function. The licensee is requested to describe its method to verify that the overall leakage limit is being met to support the implementation of the AST license amendment, and also to describe how this differs from the current requirements for leakage determination for these valves.
FPL Response:
Direct measurement of the leak tightness of valves MOV-*-856A and B and MOV-*-864A and B is difficult to perform due to the existing design of the system piping. The method proposed in Alternative Request VR-02 is to confirm adequate fit and finish of the valve seats and discs, and that the motor operators are applying the proper sealing force.
The current large break loss-of-coolant accident (LOCA) dose analysis for Turkey Point Units 3 and 4 assumes that the total refueling water storage tank (RWST) back leakage from the safety injection system is 1. 7 gph. This is the combined leakage from valves MOV-*-856A/B and MOV-*-864A/B.
Based on a simple ratio of valve diameters gives an 11 % contribution by the 2-inch diameter MOV-
- -856A/B pathway and an 89% contribution by the 16-inch MOV-*-864A/B pathway.
Section 5.2 of Appendix A-1 to Regulatory Guide 1.183, Alternative Radiological Source Terms For Evaluating Design Basis Accidents At Nuclear Power Reactors, requires that the assumed leakage rate be a factor of two higher than the sum of the actual valve leak rates. Based on this requirement, the leakage contribution for the MOV-*-856A/B pathway is 0.09 gph (0.11 x 1. 7 x 0.5 = 0.09). The leakage contribution for the MOV-*-864A/B pathway is 0.76 (0.89 x 1.7 x 0.5 = 0.76).
Valves MOV-*-856A/B are 2-inch Copes-Vulcan globe valves. To provide the required leak tightness, the motor operators for these valves are setup provide Class V leakage requirements. A Class V leakage rate is defined by ANSI/FCI 70 2006, Control Valve Seat Leakage, as 0.0005 ml/minute of water per inch of port diameter per psi differential and is the most limiting leakage class. For MOV-
- -856A/B, the port diameter is 2.086 inches. The high-head safety injection (HHSI) pump discharge pressure is approximately 1543.5 psi in the piggyback alignment based on the data provided in calculation CN-SEE-IV-08-11, Calculation of Turkey Point Unit 3 & 4 ECCS Recirculation Flows for the Extended Power Uprate. A more conservative value of 1711 psi is used in the Class V sealing load calculation. The resulting Class V leakage rate for the MOV-*-856A/B pathway is 0.028 gph at this maximum dp value. This is less than the leak rate of 0.09 gph permitted for this pathway by the LOCA dose analysis.
Valves MOV-*-864 are 16-inch Anchor/Darling gate valves. The vendor provided a leak tightness of 10 cc/hr per inch of valve size at the design differential pressure of 720 psi. This equates to a leakage rate of 160 cc/hr or 0.042 gph for a properly seated valve. This is conservative for valves MOV-*-864 since the differential pressure is expected to be approximately 200 psi during the post-LOCA recirculation alignment of the HHSI system. This leakage value is well within the leak rate of 0. 76 gph permitted for this pathway by the LOCA dose analysis.
The Turkey Point MOV program ensures that the motor-operators are applying the proper sealing force. The blue check will ensure that the seat and disc are maintaining proper surface contact. This will indirectly provide confirmation that RWST back leakage is being maintained within required limits.
Turkey Point Nuclear Plant Docket Nos. 50-250 and 50-251 Question 4 (EMIB-RAI-VR-02-04)
L-2025-025 Enclosure Page 7 of 8 Alternative Request VR-02 proposes that periodic internal inspections of each applicable valve be conducted every three refueling outages in lieu of 2-year leak testing of each valve. The licensee is requested to describe the sampling of valves for internal inspection each refueling outage to identify seat degradation prior to the sealing capability becoming unacceptable.
FPL Response:
The internal valve inspections of MOV-*-856NB and MOV-*-864NB will be performed during refueling outages due to the technical specification impact of removing the associated flow paths from service during plant operation. The Turkey Point units are currently operating on an 18-month refueling cycle but will be transitioning to a 24-month refueling cycle beginning with the Unit 4 outage in Spring 2025. It is requested that the alternative testing proposed by relief request VR-02 be granted for a four refueling outage frequency when applied to a 24-month operating cycle. This will allow coordination of the internal inspections with MOV diagnostic testing. The valve inspections will be staggered such that the time between inspections of redundant components would be less than three refueling outages. The proposed alternative would tentatively begin the next scheduled Unit 3 outage in Spring 2026 and Unit 4 outage in Spring 2025.
Valves MOV-3-856NB and MOV-3-864B were disassembled and internally inspected during the recent refueling outage in October 2024 to provide a baseline for the proposed alternative inspections. Blue checks of the seat-to-disk interface were performed with satisfactory results. The motor-operators for valves MOV-3-856NB were also setup to provide Class V sealing loads.
Question 5 (EMIB-RAI-VR-02-05)
Alternative Request VR-02 states:
In addition to the proposed alternative to conduct inspections of the valve seating surface every three refueling outages via performance of a disk-to-seating surface blue check, and perform repairs as warranted, these additional, programmatic controls further assure cumulative leakage across MOV-856A, B and MOV-864A, B will not exceed the leakage quantities assumed in the safety analyses.
The licensee is requested to describe the actions required by Alternative Request VR-02 with respect to the reduction in inspection interval of the specific valve and the group of valves, if the proposed inspections or MOV diagnostics indicate that the leakage limits might be exceeded.
FPL Response:
Inspection findings that would indicate that the leakage limits might be exceeded would be rare during the eight-year time period between inspections since the valves would only be repositioned during refueling outage related testing or maintenance activities. Nevertheless, if unsatisfactory blue check results would warrant seating surface repairs, they would be completed prior to returning the valves to operable status. The identification of any time-dependent failure modes or degradations would be evaluated and potentially subject the valves to more frequent inspections in accordance with the Turkey Point Equipment Reliability Program.
A review of valve performance over the past ten years identified one failure to close on demand for valve MOV-4-864A during the Cycle 32 refueling outage in 2020. The failure to close on demand was caused by a failed torque switch. The torque switch contacts on the closed side would not actuate with the corresponding valve movements. The torque switch was subsequently replaced. As an additional corrective action, the MOV actuator inspection procedure performed each refueling outage
Turkey Point Nuclear Plant Docket Nos. 50-250 and 50-251 L-2025-025 Enclosure Page 8 of 8 was revised to include verification of torque switch operation, cleanliness of electrical contacts, and inspection for any contact binding.
References:
- 1.
Florida Power & Light Company letter L-2024-106, Fifth and Sixth 10-Year lnservice Testing Interval Relief Request No. VR-02, August 12, 2024 (ADAMS Accession No. ML24225A100)
- 2.
Nuclear Regulatory Commission electronic memorandum dated January 13, 2025, Request for Additional Information Related to Turkey Point Nuclear Plant Relief Request VR MOVs biennial leakage test requirement (EPID L-2024-LLE-0059) (ADAMS Accession No. ML25013A301)