NLS2025011, Inservice Testing Code of Record Interval Relief Requests for Pumps, Valves, and Snubbers

Inservice Testing Code of Record Interval Relief Requests for Pumps, Valves, and Snubbers

ML25065A116
Person / Time
Site:	Cooper
Issue date:	03/04/2025
From:	Dia K Nebraska Public Power District (NPPD)
To:	Office of Nuclear Reactor Regulation, Document Control Desk
References
NLS2025011
Download: ML25065A116 (1)

Text

{{#Wiki_filter:N Nebraska Public Power District "Alwa'1s therc wlw 1ou need us" 10 CFR 50.55a NLS2025011 March 4,2025 U.S. Nuclear Regulatory Commission Attention: Document Control Desk Washington, D.C. 20555-0001

Subject:

Inservice Testing Code of Record Interval Relief Requests for Pumps, Valves, and Snubbers Cooper Nuclear Station, Docket No. 50-298, Renewed License No. DPR-46 The purpose of this letter is for the Nebraska Public Power District (NPPD) to request that the Nuclear Regulatory Commission (NRC) grant relief from certain Inservice Testing (IST) code requirements for Cooper Nuclear Station (CNS) pursuant to 10 CFR 50.55a. The attached relief requests pertain to the American Society of Mechanical Engineers (ASME) Code for Operation and Maintenance (OM) of Nuclear Power Plants pump, valve, and snubber testing requirements needed for the next Code of Record (COR) IST interval, which commences on March 1,2026, and will end on February 28,2050. The COR Interval will encompass the next two consecutive Inservice Examination and Test Intervals (6th and 7th) as described in 10 CFR 50.55a(y)(2), which are being extended from l0 years to 12years each based on the implementation of conditionally acceptable ASME OM Code Case OMN-31, "Altemative to Allow Extension of ISTA-3120 Inservice Examination and Test Intervals From 10 Years to 12Years." As required per Regulatory Guide L192, revision 5, "Operation and Maintenance Code Case Acceptability, ASME OM Code," the conditions required to implement code case OMN-31 will be met. CNS will be implementing an acceptable Edition of the ASME OM Code (2022 Edition), the code case will be implemented at the beginning of an interval, and the requirements of ISTA-3120 will have been satisfied. CNS has elected to update to the 2022Edition of the ASME OM Code for the upcoming COR Interval, which is the latest edition incorporated by reference in 10 CFR 50.55a(a)(1)(iv). Per 10 CFR 50.55a(f(a)(iv), NRC approval is not required when updating to the latest edition before the start of an IST interval. NPPD requests approval of these relief requests by March 1,2026, in support of the start of the next COR IST interval. This update is for pumps, valves and snubbers. Relief requests previously approved for the fifth ten-year interval are being updated and resubmitted, as applicable, for the upcoming COR Interval requirements. Relief Request RV-05 is a new relief request. Attachment I contains a summary listing of the changes for the upcoming COR Interval. Attachment 2 contains the upcoming COR Interval IST relief requests. COOPER NUCLEAR STATION 72676 648A Ave / P.O. Box g8 / Brownville, NE 68321 http://www.nppd.com

/dv NLS2025011 Page2 of 2 No formal licensee commitments are being made or modified by this submittal. Should you have any questions concerning this matter, please contact Linda Dewhirst, Regulatory Affairs & Compliance Manager, at (402) 825-5416. Sincerely, Dia Site Vice President Attachments l. Cooper Nuclear Station Pump, Valve, and Snubber Inservice Testing Program Summary of Changes for the Code of Record (COR) Interval 10 CFR 50.55a Relief Requests

2. Cooper Nuclear Station Pump, Valve, and Snubber Inservice Testing Program Code of Record (COR) Interval 10 CFR 50.55a Relief Requests cc: Regional Administrator w/ attachments USNRC - Region IV Cooper Project Manager d attachments USNRC - NRR Plant Licensing Branch IV Senior Resident Inspector d attachments USNRC - CNS NPG Distribution w/ attachments CNS Records w/ attachments

NLS202501 I Page 1 of2 Attachment I Cooper Nuclear Station h-p, Valve, and Snubber Inservice Testing Program Summary of Changes for the Code of Record (COR) Interval 10 CFR 50.55a Relief Requests Relief Request (RP:Pump) @V:Vatve) @S:Snubber) (RG:General) Approved Fifth Ten-Year Interval Relief Request, ending 2-28-2026 Proposed Relief Requests for COR Interval Beginning 3-l-2026 and Ending 2-28-2050 RP-01 Core Spray Pump Suction Gauge Range Requirements RP-01: Combined RP-01, RP-02, RP-03, RP-04, and RP-06 into one relief request based on American Society of Mechanical Engineers (ASME) Code for Operation and Maintenance (OM) Code Case, OMN-32, revision 1, "Alternative Requirements for Range and Accuracy of Pressure, Flow, and Differential Pressure Instruments Used in Pump Tests." The technical basis remains the same as in the previously approved relief requests. RP-05 is not required. The calibration tolerances meet the Instrument Loop Accuracy definition in Subsection ISTA-2000 Definitions. RP-02 Residual Heat Removal Pump Suction Gauge Range Requirements RP-O3 High Pressure Coolant Injection Pump Suction Gauge Range Requirements RP-04 Reactor Core Isolation Cooling Pump Suction Gauge Range Requirements RP-05 Loop Accuracy Requirements for Misc.Instruments RP-06 Reactor Equipment Cooling Pump Flow Rate Range Requirements RP-07 Core Spray Pump B Vibration Alert Limits RP-02: Updated applicable ASME OM Code, clarified applicable code requirements, revised proposed alert limits for vibration points lH and 5H to more appropriate values, updated the reason for request, basis, maintenance history, vibration trends, D/P trend, and precedents (added Byron precedence with 0.55 in/s alert value). RP-O8 Comprehensive Pump Test Upper Limit Relief Request is not required. Implernented into the ASME OM Code. RP-O9 Variance Around the Reference Values Relief Request is not required. Implemented into the ASME OM Code. RV-OI High Pressure Coolant Injection Solenoid Operated Drain Valve Testing RV-01: Updated applicable ASME OM Code, maintenance histories, and precedents. The technical basis remains the same. RV-02 Main Steam Safety Valve Testing per Code Case OMN-17 Relief Request is not required. Implemented into the ASME OM Code. RV-03 Main Steam Safety Relief Valve Testing RV-02: Updated applicable ASME OM Code, reason for request, and precedents. The technical basis remains the same.

NLS20250I 1 Page2 of2 Relief Request (RP=Pump) (RV=Valve) (RS:Snubber) (RG:General) Approved Fifth Ten-Year Interval Relief Request, ending 2-28-2026 Proposed Relief Requests for COR Interval Beginning 3-l-2026 and Ending 2-28-2050 RV.O4 Control Rod Drive Technical Specification Testing RV-03: Updated Applicable ASME OM Code and precedents. The technical basis remains the same. RV-05 Performance-Based Scheduling of Pressure Isolation Valve Leakage Tests. RV-04: Updated Applicable ASME OM Code, reason for request, ASME OM Code sections for functional testing, maintenance history, Pressure Isolation YalvelLocal Leak Rate Test test histories, and precedents. The technical basis remainS the same. N/A RV-05: New Relief Request for Supplernental Position Indication Testing of Control Rod Drive Scram Discharge Volume Vent & Drain Valves. Referenced precedence from Browns Ferry. RS.Ol Examination Interval for Snubbers RS-01: Changed name of relief request to Grace Period for 1O-Year Snubber Examinations. Ten-year exam portion of previous reliefrequest has been incorporated into the ASME OM Code. Relief is for grace period on ten-year exam interval. Updated Applicable ASME OM Code, Code Requirements, and precedents. Revised the graceperiod from 90 days to 120 days based on the ISTD test campaign date changes. The technical basis remains the same. RG-01 ASME OM Code Test Frequencies Relief Request is not required. Implemented into the ASME OM Code.

NLS202501 1 Page I of 91 ATTACHMENT 2 Cooper Nuclear Station Pump, Valve, and Snubber Inservice Testing Program Code of Record (COR) Interval f0 CFR 50.55a Relief Requests RELIEF REQUEST INDEX Relief Request No. Description Page Number(s) Pumps RP-OI fump Suction Pressure and Flow Range Requirements 2-5 RP-02 Core Spray Pump B Vibration Alert Limits 6-41 Valves RV-O1 HPCI Solenoid Operated Drain Valve Testing 42-47 RV-02 Main Steam Safety Relief Valve Testins 48-sl RV-03 Control Rod Drive (CRD) Technical Specification Testing 52-s4 RV-04 Performance-Based Scheduling of Pressure Isolation Valve Leakage Tests 55-8 1 RV-05 Supplemental Position Indication Testing of CRD Scram Discharge Volume (SDV) Vent and Drain Valves 82-86 Snubbers RS-01 Grace Period for lO-Year Snubber Examinations 87-90

NLS20250l 1 Page 2 of 9l Relief Request RP-01 Pump Suction Pressure and Flow Range Requirements Proposed Alternative in Accordance with 10 CFR 50.55a(z)(1) Alternative Provides Acceptable Level of Quality and Safety

1.

ASME Code Component(s) Affected CS-P-A/B HPCI-P-MP & HPCI-P.BP RCIC-P-MP REC-P-A/B/C/D RHR-P-A/B/C/D Core Spray Pumps High Pressure Coolant Injection Main & Booster Pumps Reactor Core Isolation Cooling Main Pump Reactor Equipment Cooling Pumps Residual Heat Removal Pumps

2.

Applicable Code Edition and Addenda

American Society of Mechanical Engineers (ASME) Code for Operation and Maintenance of Nuclear Power Plants (OM Code) 2022Edition.

3.

Applicable Code Requirement

ISTB-3510O)(l) - The full-scale range of each analog instrument shall not be greater than three times the reference value.

4.

Reason for Request

Pursuant to 10 CFR 50.55a, 'oCodes and Standards," paragraph (z)(1), relief is requested from the requirement of ASME OM Code ISTB-3510(b)(1). The proposed alternative would provide an acceptable level ofquality and safety. The installed analog suction pressure gauge ranges for the Core Spray (CS) pumps, Residual Heart Removal (RHR) Pumps, High Pressure Coolant Injection (HPCD Pumps, and Reactor Core Isolation (RCIC) Pumps exceed the full-scale range requirement of ISTB-3510(bX1) based on the approximate suction pressures observed during inservice testing (IST). The installed analog flow rate instrument range of the Reactor Equipment Cooling (REC) Pumps is 0 to 4000 gpm. The instrument range exceeds the requirement of ISTB-3510(bxl) based on a reference value of I 100 gpm during inservice testing.

5.

Proposed Alternative and Basis for Use The IST test parameters determined from the instruments described above meet the accuracy requirements of ASME OM Code Case OMN-32, revision 1 "Alternative Requirements for Range and Accuracy of Pressure, Flow, and Differential Pressure Instruments Used in Pump Tests." Revision 1 of this code case, which is approved by the ASME OM Code Standards Committee (Record 24-48, Ballot 24-3500), states the following:

NLS20250l 1 Page 3 of 91 Relief Request RP-01 Pump Suction Pressure and Flow Range Requirements (Continued) Inquiry: What alternative to the requirements of ISTB-3510(a) [ISTF-3510(a)], ISTB-3510(bXl) [ISTF-351O(bxl)] and ISTB-3510(bX2) USTF-3510(b)(2)l for the accuracy and range of flow, pressure, and differential pressure instruments may be used for Group A, Group B, Comprehensive, and Preservice pump tests? Reply: It is the opinion of the Committee that in lieu of ISTB-3510(a) [ISTF-3510(a), ISTB351O(bXl) [ISTF-351O(bX1)], IsTB-3s10(b)(2) USTF-3510(bX2)1, and Table ISTB 3s10-1 [Table ISTF-3510-l], the following requirements may be applied to instruments used to measure pump pressure, flow rate, and differential pressure.

l. Required Instrument Accuracy and Range (a) Accuracy. The analog or digital instrument(s) shall be calibrated within the limits specified in Table I for the respective test quantity. For an instrument loop, the required accuracy is instrument loop accuracy as defined in ISTA-2000. If a parameter is determined by analytical methods instead of measurement, then the determination shall meet the parameter accuracy requirements of Table 1.

(b) Range. The analog or digital instrument(s) shall be designed and calibrated in the range for use at the expected reading to be measured or recorded during the test (e.g., reference value and applicable acceptance criteria). Table 1 Required Instrument Accuracy Quantity Group A and Group B Tests. % of Readine Comprehensive, Baseline, and Preservice Tests % of Reading Pressure +6 +t% Flow Rate +6 +6 Differential pressure +6 +lY2 The basis behind this code case is that the maximum full-scale range for an analog instrument is three times the reference value per ISTB-3510(bX1). The ASME OM Code Group A and Group B Pump test accuracy requirements for pressure, flow rate, and differential pressure are *2oh of full scale for analog instruments per ISTB-3 5 1 0(a) and Table ISTB-3 5 I 0- 1. Therefore, the maximum allowed error allowed by the ASME OM Code at the reference value (reading) for Group A and Group B pump test parameters would be up to +60/o of thereference value (reading). Similarly, based on the comprehensive, baseline, and preservice accuracy requirements for pressure (+%yo), flow rate (+2%), and differential pressure (r%%), the second column represents the maximum allowed error allowed by the ASME OM Code at the reference value for comprehensive, baseline, and preservice pump tests. Then, Revision 1 of this code case incorporated the requirements for the Table I accuracies to apply to the expected reading to be measured or recorded during the test (e.g., reference value and applicable acceptance criteria). More information is provided within the white paper for Code Case OMN-32, revision 1 (ASME Record 24-48).

NLS202501 I Page 4 of 91 Relief Request RP-01 Pump Suction Pressure and Flow Range Requirements (Continued) Cooper Nuclear Station (CNS) Pump Suction Pressure Gauees for CS. RHR. HPCI. and RCIC: For CS, RHR, HPCI, and RCIC, the installed pump suction pressure gauge is used along with the installed pump discharge pressure gauge to determine pump differential pressure for Group A (RHR) and Group B (CS, HPCI, RCIC) pump testing. The suction pressures for these pump tests result in values that are less than three times the full-scale range of the analog suction pressure gauges. AsanaltemativetomeetingISTB-3510(b)(1)forthepumpsuctiongaugefull-scale range, the installed suction pressure gauge calibration tolerance plus the installed discharge pressure gauge calibration tolerance will result in a combined differential pressure calibration accuracy that is much better than the required instrument accuracy of Table I for Differential Pressure for Group A and Group B Pump Tests. Higher accuracy suction and discharge pressure gauges will be installed when performing the comprehensive, baseline, or preservice tests. The analog instruments being used for the suction pressure and discharge pressure for the Group A or Group B tests, as applicable, are designed and calibrated in the range for use at the expected reading to be measured or recorded during the test (e.g. reference value and applicable acceptance criteria). Therefore, all requirements of Code Case OMN-31, revision l, have been met. The calibration data sheets are available at CNS for inspection, as necessary. Flow instrument for REC Pump Tests The installed analog flow rate instrument range for each Reactor Equipment Cooling Pump is 0 to 4000 gpm. The instrument range exceeds the requirement of ISTB-3510(bX1) based on a reference value of 1100 gpm during inservice testing. As an altemative to meeting ISTB-3510(bX1) for the flow rate gauge full-scale range, CNS will use the installed flow rate instrumentation (0 to 4000 gpm) calibrated to better than t 2%o suchthat the instrument accuracy due to flow will be less than or equal to that required by Table I for Flow Rate. The analog instruments being used are designed and calibrated in the range for use at the expected reading to be measured or recorded during the test (e.g. reference value and applicable acceptance criteria). This relief request is applicable for the flow instrument being used for all potential REC pump tests (i.e. Group A, Comprehensive, Baseline, and Preservice Tests). Therefore, all requirements of Code Case OMN-3 I, revision 1, have been met. The calibration data sheets are available at CNS for inspection, as necessary. Conclusions Using the provisions of this relief request as an altemative to the specific requirements of ISTB-3510(bX1), identified above, will provide adequate indication of pump performance, and continue to provide an acceptable level ofquality and safety. Therefore, pursuant to 10 CFR 50.55a(z)(1), Nebraska Public Power District (NPPD) requests relief from the specific ISTB requirernents identified in this request.

NLS202501 I Page 5 of 9l Relief Request RP-01 Pump Suction Pressure and Flow Range Requirements (Continued)

6.

Duration of Proposed Alternative This proposed altemative will be utilized for the entire Code of Record interval that uses the2022 Edition of the ASME OM Code, beginning on March 1,2026, and ending on February 28th, 2050.

7.

Precedents This relief request was previously approved for the fifth ten-year interval at CNS as RP-01, RP-02, RP-03, RP-04, and RP-06 (CAC NOS. MF59l1, MF5913, MF5914, MF59l5, MF5916, MF59 1 7, MF59 I 8, MF59 1 9, MF5 g20, MF5 92 1, MF 5922, MF 5923, MF 5924, MF5 g25, and MF5926, February 12,2016 ), and the fourth ten-year interval at CNS as Relief Request RP-01, RP-02, RP-03, RP-04, and RP-06 (TAC Nos. MC8837, MC8975, MC8976,MC8977, MC8978, MC8979, MC8980, MC8981, MC8989, MC8990, MC899l, and MC8992, June 14,2006.

NLS202501 I Page 6 of9l Relief Request RP-02 Core Spray Pump B Vibration Alert Limits Proposed Alternative in Accordance with 10 CFR 50.55a(z)(2) Compliance Would Result in a Hardship Without a Compensating Increase in Quality and Safety

1.

ASME Code Component(s) Affected CS-P-B Core Spray Pump B

2.

Applicable Code Edition and Addenda

ASME OM Code 2022Edrtion

3.

Applicable Code Requirement

ISTB Table ISTB-5121-1, "Centrifugal Pump Test Acceptance Criteria" specifies an absolute vibration alert limit for the comprehensive test to be > 0.325 in/s to 0.7 inlsec. ISTB-5123(e) All deviations from the reference values shall be compared with the ranges of Table ISTB -5121-I and corrective action taken as specified in 15T8-6200. The vibration measurements shall be compared to both the relative and absolute criteria shown in the alert and required action ranges of Table ISTB-5121-1. ISTB-6200(a) If the measured test parameter values fall within the alert range of Table ISTB-5121-1, Table ISTB-5221-1, Table ISTB 5321-1, or Table ISTB-5321-2, as applicable, the frequency of testing specified in ISTB-3400 shall be doubled until the cause of the deviation is determined and the condition is corrected, or an analysis of the pump is performed in accordance with (c).

4.

Reason for Request

Pursuant to 10 CFR 50.55a, "Codes and Standards," paragraph(z)(2), relief is requested from the requirement of ASME OM Code ISTB Table ISTB-5121-1 for the absolute alert limit for two vibration points taken on Core Spray Pump B (CS-P-B) during the biennial comprehensive pump test or any other time vibrations are taken to determine pump acceptability (i.e., post-maintenance testing, other periodic testing, etc.). Compliance with the specified requirements for these two vibration points would result in a hardship without a compensating increase in the level of quality and safety. Per Subsection ISTB of the ASME OM Code, CS-P-B is categorized as a Group B standby pump at CNS that requires vibration readings to be taken during the comprehensive pump test. Due to a sporadic piping-induced resonant frequency vibration that influences vibration points 1H and 5H for CS-P-B, these two points periodically enter the absolute vibration alert range for the comprehensive pump test as specified from ISTB Table ISTB-5121-l (> 0.325 in/s to 0.700 irls). The location of these two points and the other points taken on this pump are illustrated in Figure

1. This request is based on an analysis of vibration and pump differential pressure data indicating that no pump degradation is taking place and that the resonance frequency vibrations that sporadically impact vibration points lH and/or 5H do not have an impact on the long-term

NLS20250l 1 PageT of91

5.

Proposed Alternative and Basis for Use Pump Testing Methodology Relief Request RP-02 Core Spray Pump B Vibration Alert Limits (Continued) reliability of CS-P-B. CNS is proposing to use alternative vibration alert range limits for vibration Points lH and 5H. This provides an altemative method that continues to meet the intended function of monitoring the pump for degradation over time while keeping the required action level unchanged. CS-P-B at CNS is tested using a full flow recirculation test line back to the suppression pool each quarter. CS-P-B has a minimum flow line which is used only to protect the pump from overheating when pumping against a closed discharge valve. The minimum flow line isolation valve for CS-P-B is initially open when the pump is started, and flow is initially recirculated through the minimum flow line back to the suppression pool. Then, the full-flow test line isolation valve is throttled open to establish flow through the full-flow recirculation test line. The minimum flow line is then isolated automatically, and all flow remains through the full-flow test line for the IST test. The B train of the CS system is operated in the same manner and under the same conditions for each test of CS-P-B, regardless of whether CNS is operating or shut down. Consequently, the pump will experience the same potential for flow-induced, low frequency vibration whenever it is tested, whether CNS is operating or shut down. As a result, this relief is requested for the vibration measurements required during the comprehensive pump testing of CS-P-B when vibration measurements are required or any other time vibrations are recorded to determine pump acceptability (i.e., post-maintenance testing, other periodic testing, etc.). CNS considers full-flow testing to be preferable to minimum flow testing due to the ability to evaluate overall pump performance at post-accident flow design conditions. Minimum flow testing would provide only limited information about the pump. Nuclear Regulatory Commission (NRC) Staff Document NUREG/Cp-0152 NRC Staff document NUREG/CP-0152, entitled "Proceedings of the Fourth NRC/ASME Symposium on Valve and Pump Testing," dated July 15-18, 1996, included a paper entitled Nuclear Power Plant Safety Related Pump Issues, by Joseph Colaccino of the NRC staff. That paper presented four key components that should be addressed in a reliefrequest ofthis type to streamline the review process. These four key components are as follows: The licensee should have sufficient vibration history from inservice testing which verifies that the pump has operated at this vibration level for a significant amount of time, with any "spikes" in the data justifred. The licensee should have consulted with the pump manufacturer or vibration expert about the level of vibration the pump is experiencing to determine if pump operation is acceptable. I. II.

NLS202501 1 Page 8 of91 ilI IV Relief Request RP-02 Core Spray Pump B Vibration Alert Limits (Continued) The licensee should describe attanpts to lower the vibration below the defined code absolute levels through modifications to the pump. The licensee should perform a spectral analysis of the pump-driver system to identify all contributors to the vibration levels. The following is a discussion of how these four key components are addressed for this relief request. I. Vibration History (Key Component No. 1) A. Testing Methods and Code Requirements Inconsistent higher vibrations on CS-P-B for vibration points lH and 5H have been a condition that has existed since original installation of this pump in 1973. During the construction and preoperational testing, vibrations were measured in "mils" at the top and side of the motor outboard (farthest from the pump), the side of the motor inboard (nearest the pump), and pump inboard (nearest the motor). The vibration signals were tape recorded along with the dynamic pressure pulsations in the suction and discharge of the pump as the flow was varied. The intention was to see if hydraulic disturbances were responsible for the observed phenomena. Observation of the vibration signals on the oscilloscope showed conclusively that the motor was vibrating with randomly distributed bursts of energy at the natural frequency of the total system. Therefore, it was determined that the hydraulic disturbances found in the piping was the source of the energy. Pipe restraints were added that reduced the piping system vibrations. The monitoring of multiple vibration points over the years had not been a requirement of Section XI of the ASME Code until the adoption of the OM Standards/Codes. Therefore, at CNS, the first and second ten-year interval IST code requirements did not include the monitoring of multiple vibration points. The CNS second interval IST Program was committed to the 1980 Edition, Winter 1981 Addenda of Section XI. Paragraph IWP-4510 of this code required that "at least one displacement vibration amplitude shall be read during each inservice test." This code was in effect at CNS until the start of the third ten-year interval, which began on March 1,1996. The CNS third interval IST Program was committed to the 1989 Edition of Section XI, which required multiple vibration points to be recorded during IST pump testing in accordance with the ANSI/ASME Operations and Maintenance Standard, Parl 6, 1987 Edition with the 1 988 Addenda. However, CNS proactively began monitoring vibration on pumps in the IST Program in velocity units (inches per second) at multiple vibration points in 1990 in accordance with an approved reliefrequest. Therefore, data exists for vibration Points iH and 5H from April 1990 to the present. This data is included in the figures provided in this relief request. In April 1990, an analog velocity meter was utilized to begin measuring five different points in units of velocity. These are the same points measured today. Further technological advances resulted in the utilization of more reliable vibration meters beginning in late 1 996. For the fourth interval, which began on March I, 2006 and ended

NLS202501 I Page 9 of91 Relief Request RP-02 Core Spray Pump B Vibration Alert Limits (Continued) on February 28,2016, the 2001 Edition through 2003 Addenda of the ASME OM Code was the code of record. The fifth interval, beginning on March 1,2016, utilized the 2004 Edition through the 2006 Addenda. The fourth and fifth ten-year intervals only required vibration measurements to be taken during the comprehensive test since the CS-P-B pump is considered a Group B pump. The same will be true for the Code of Record Interval, begiruring on March 1,2026, in which the2022 Edition of the ASME OM Code will be the code of record. B. Review of Vibration and Differential Pressure History Data Begirming in April 1990, five vibration points (1V, 1H, 2H,3H,5H) were recorded for CS-P-B. However, the pump was tested at 4720 gpm from April 1990 to April 1992, then at 4800 gpm from April 1992tbrough December 1994, and finally at 5000 gpm from January 1995 to the present. The January 1995 test was also a post-maintenance test following the work that replaced the restricting orifice in the test return line. The last re-baseline occurred on Novernber 6,1996, due to the implementation of a new vibration meter with new instrument settings. Therefore, it would be appropriate to review the data from this date forward to track for degradation. This would be over 28 years of data at the same set flow value of 5000 gpm and-34.5 years of data at approximately the same flow (4720 gpm to 5000 gpm). From the fourth interval forward, the data also includes testing that administratively took vibrations at the IST flow of 5000 gpm outside of the ASME OM Code required comprehensive pump testing. IST trends for vibration points lH and 5H from November 6,1996 to the present (Figures 2aand 3a) illustrate how the sporadic piping-induced vibrations have impacted these two vibration points since the last re-baseline of the pump. Similarly, the trends for these two points from April of 1990 to the present (Figures 2b and 3b) with the proposed alert value for each point superimposed onto each graph (0.55 in/s for vibration point 1H and 0.48 in/s for vibration point 5H) illustrates how these proposed new alert values would fully encompass the maximum values recorded since 1990 for these two points with approximately 0.03 in/s margin. Taking a more specific look at figure 2b for vibration point lH, the sporadic nature of the vibration has resulted in values being recorded anywhere from approximately 0.13 inls to approximately 0.52 inls. The key observation is that the higher values that have been recorded within this range have not increased in magnitude over time based on the past -34.5 years of data. Values near 0.5 irls were recorded in February 1993 in addition to approximately 3 times since 2018. When the higher vibration values will occur are totally unpredictable due to the random nature ofthe resonant vibration influence on the value. Therefore, the three higher values recorded since -2018 is not indicative of a degrading condition. Also, spectral data reviews have demonstrated that vibration point lH has consistently been influenced by the piping-induced resonance frequency. Analysis of the spectral data will be covered in more detail later in the relief request. Taking a more specific look at figure 3b for vibration point 5H, the sporadic nature of the vibration has resulted in values being recorded anywhere from approximately 0.10 in/s to approximately 0.45 in/s. The key observation is that the higher values that have been

NLS20250l 1 Page 10 of91 Relief Request RP-02 Core Spray Pump B Vibration Alert Limits (Continued) recorded within this range have not increased in magnitude over time based on the past -34.5 years of data. A value of 0.45 inls was recorded in June 1993 in addition to a similar value more recently in August of 2019. Again, when the higher vibration values will occur are totally unpredictable due to the random nature of the resonant vibration influence on the value. Also, spectral data has demonstrated that vibration point 5H has consistently been impacted by the piping-induced resonance frequency. Analysis of the spectral data will be covered in more detail later in the relief request. CS-P-B IST vibration trend graphs for vibration points lV,2H, and 3H (Figures 4a,5a, and 6a in this relief request), which include data from November 6,lgg6,to the present, illustrate steady, low vibration values, with no degradation over approximately 28 years of data since the last time the pump was re-baselined. Similarly, trend graphs 4b, 5b, and 6b, with data dating back to April of 1990, illustrate the same steady, low vibration, trends with no degradation over time for these same three vibration points. Figure 12 illustrates the trend for CS-P-B differential pressure (D/P) readings from January 1995 (re-baselined pump at 5000 gpm) to the present. This represents approximately thirty years of data for pump D/P with the testing at 5000 gpm. As can be seen from Figure 12,no degradation in pump DIP has occurred. Trend Graphs 2b,3b,4b,5b, and 6b illustrate vibration data dating back to April 1990 for all vibration points. The data prior to 1996 represents data taken with analog, less reliable vibration instruments and, as discussed previously, at slightly differing flows. However, it does clearly indicate that the piping-induced vibrations for vibration points lH and 5H were present in the early 1990s. This condition was also documented in the 1980s. In July 1985, CNS work item #85-2497 documented high vibration readings on the horizontal motor position. A pipe resonance problan was suspected at that time. Vibrational readings varied between 0.3 and 0.5 inlsec with spikes to 0.7 in/sec every few seconds. This 1985 documentation, available vibration data since 1990, along with the testing performed during the preoperational time period, substantiates that the piping-induced vibrations have been in existence since the pump was installed. Therefore, based on a review of the overall IST vibration values for CS-P-B, trend graphs for vibration points lV,2H, and 3H since April 1990 represent consistently low vibration values with no degradation and no impact from the piping-induced resonant frequencies. Vibration points lH and 5H have continued to demonstrate the impacts from the piping-induced resonant vibrations, but the magnitude of the highest vibrations observed have not increased in over -34.5 years. Therefore, based on the available data at CNS, this pump has experienced essentially no degradation in vibration levels for -34.5 years or in D/P for -30 years. C. Review of "Spikes" in Vibration Data In reviewing the trend data for vibration points lH (Figures 2a and 2b) and 5H (Figures 3a and 3b), which includes the code-required frequency ranges (onethird pump running speed to 1000 Hertz lHzl.), random spikes were observed throughout the data that

NLS20250l l Page 11 of91 Relief Request RP-02 Core Spray Pump B Vibration Alert Limits (Continued) resulted in values above the alert range. These spikes are best described in a 2001 report by Machinery Solutions, Inc., an industry expert on vibrations, as follows: Most of the vibration that is measured on the motor casing is due to excitation of the structural resonances of the motor/pump by turbulent flow. These structural resonances are poorly damped and can be easily excited. Most vertical pumps have similar types of behavior, and it is not necessarily problematic by itself. A problem occurs when a pump has a continuous forcing function whose frequency coincides with a resonance (i.e., running speed). The forcing function in this case is flow turbulence caused in large part by the S-curve in the piping just off the pump discharge. The flow through this area generates lateral broadband forces, due to elbow effects, that excite the resonances in a non-continuous fashion. This is why the amplitude swings so dramatically on the motor case (the location of vibration points lH and 5H). The system goes from brief periods of excitation to brief periods of no excitation. The discharge riser is also moving side to side from the same forces. Although the discharge piping configuration is both non-standard and less than optimum for this application, it poses no threat to the long-term reliability of either the pump ff the motor. The only negative impact is on vibration levels relative to a generic standard. As illustrated previously, there have been no degrading trends associated with vibration data points lH and 5H for -34.5 years (Figures 2b and 3b). Since Jrtne 2002, filtered data (removal of one-third pump running speed to one-half pump running speed frequencies) has been recorded in addition to the current code-required values for vibration points lH and 5H (reference Figures 2c and 3c for data since February of 2020) In reviewing this data, the trends are lower in value, steady, and without the spikes that the code-required data contains. This further supports the fact that the spikes in the original code data are due to the piping-induced, non-detrimental vibration occurring at the one-third to one-half pump running speed. II. Consultation - Pump Manufacturer/Vibration Expert (Key Component No. 2) A. Pump Manufacturer Evaluation of CS-P-B Vibrations Byron Jackson is the pump manufacturer for GS-P-B. The pump is an 8 x 14 x 30 DVSS, vertical mount, single stage centrifugal pump. The pump impeller is mounted on the pump motor's extended shaft. As outlined in the Core Spray System Summary of Preoperational Test, the data obtained for the B Core Spray Pump indicated high vibration. The high vibration had been recognized early in the construction testing phase, and Byron Jackson sent a representative to the site to investigate. In a letter dated February 76,1973Property "Letter" (as page type) with input value "05000298/LER-1917-001, Regarding Residual Heat Removal Minimum Flow Valves Out of Position Results in Loss of Safety Function and Condition Prohibited by Technical Specifications"February 76, 1973" contains a sequence that could not be interpreted against an available match matrix for date components." contains invalid characters or is incomplete and therefore can cause unexpected results during a query or annotation process., the Byron Jackson representative indicated the following:

NLS20250l I Page 12 of91 2 3 Relief Request RP-02 Core Spray Pump B Vibration Alert Limits (Continued) Tests indicated that the natural frequency of the pump was 940 revolutions per minute (rpm) (approximately one-half pump speed) in the direction of the piping and720 rpm (between one-third and one-half of pump speed) in the direction perpendicular to the piping. Observation of the test signals on the oscilloscope showed very conclusively that the motor was vibrating with randomly distributed bursts of energy, the frequency of which matched the natural frequency of the total system. This can only mean that the energy is coming from the hydraulic disturbances found in the prpng. Whenever large flows are carried in piping, there is usually considerable turbulence associated with the elbows, tees, etc., of the piping configuration, all of which results in piping reactions and motion. Apparently, the vibrating piping was, in turn, vibrating the pump. 4. When jacks were installed between the top of the pump and the bottom of the motor flange in an effort to stiffen the motor pump system, the motor vibrations went up due to more energy being transmitted from the pipe-pump system into the motor. Testing was performed to determine any weaknesses in the pump-motor mechanical system. The vibration amplitude using the IRD instrument, with the filter set at operating speed, sampled many points vertically along the pump-motor structure. Plots of the data (along with phase angle determined by means of the strobe light) showed very clearly that the total structure was vibrating as a rigid assanbly from the floor mounting. Examination of the high amplitude vibration signals showed them to be at the extremely low system natural frequencies as determined earlier. 6. Such low acceleration levels, along with the system acting as a rigid structure (between motor and pump), means that the motor and pump can operate with these levels of vibration with absolutely no impairment of operating life. This is the picture that seems very clearly described by the data obtained during these tests. There is absolutely no reason to restrict the operation of these pumps in any way. Although the vibration was found to be acceptable, CNS took actions to install new pipe supports as an attempt to reduce these piping-induced vibrations. This action was successful as will be discussed in a later section of this relief request. B. CNS Expert Analysis of CS-P-B Vibrations As the Vibration Monitoring Program expanded in the early 1990s, it became evident that the low frequency, piping-induced vibrations still remained in CS-P-B. Design Change (DC) 94-046 resulted in the replacement of the orifices in the test return line. A March 16,1995, memo to the CNS IST Engineer from the CNS Lead Civil/Structural Engineer 5

NLS202501 1 Page 13 of9l Relief Request RP-02 Core Spray Pump B Vibration Alert Limits (Continued) discussed the CS-P-B vibration measurements obtained during DC 94-046 acceptance testing. The vibration data was collected using peak velocity measuring instrumentation as required for the performance of the IST test and with instrumentation that provides displacement and velocity versus frequency data. It was observed that the significant vibrations in the lH direction were occurring around 700 cycles per minute (cpm), while the pump speed is at 1780 cpm (i.e., rpm). Given the piping movernent of the system, and the knowledge that piping vibrations can commonly occur in the 700 cpm(72H2) range, CNS concluded that the pump vibrations were piping dependent. The CNS Lead CiviVStructural Engineer concluded that the significant pump vibrations are occurring at less than one-half of the pump operating speed. The pumps are rigidly mounted at their bases, and any impeller-induced vibrations would occur at the pump running speed or at the vane passing frequency. Therefore, the sub-synchronous pump vibrations are clearly piping induced, non-detrimental to pump/motor service or reliability, and should not be used as a basis for pump degradation. This is because the purpose of pump in-service testing is to diagnose and trend internal pump degradation. The memo further states that the vibration data collection requirement specified in the IST procedure consists of peak velocity recordings, which may be masked by piping-induced vibrations, negating intemal pump degradation diagnosis and trending. Based on the historical trending data for both CS pumps, the vibration has remained at a consistent amplitude, trending neither upward nor downward, indicating that the induced vibrations are not impairing pump operability, nor capable of preventing the pump from fulfilling its safety function. The piping vibration is present when flow is present through the test retum line. It was visually observed during DC 94-046 acceptance testing that piping vibrations were minimal when flow was directed through the minimum flow line. Following the DC 94-046 testing, CNS noted that the deflections observed in the discharge piping were significantly reduced. Based on these results, it was determined by the Nuclear Engineering Department, CiviVstructural Group, that the CS Loop B piping vibration stresses are less than the endurance limit of the piping. On October 17,2002, a Plant Engineering Supervisor at CNS, knowledgeable in the area of pump vibration analysis, issued a memo to the CNS Risk & Regulatory Affairs Manager discussing the low frequency vibration issue with the CS-P-B. In the memo, it is stated that the pipe is vibrating as a reaction to flow turbulence, which in turn is causing the pump to vibrate. The memo documents the basis for why the low frequency vibration (less than one-half pump running speed) experienced during CS-P-B operation is not indicative of degrading pump performance and is not expected to adversely impact pump operability. To summarize, in the area of pump performance, aside from the randomness of the low frequency peaks, the spectral data shows no degrading trend in performance over several years of data. The low frequency piping-induced vibrations are not expected to adversely impact pump operability.

NLS2025011 Page 14 of9l Relief Request RP-02 Core Spray Pump B Vibration Alert Limits (Continued) C. Indenendent Industrv Vibrati Exoert Evaluation of CS-P-B In 2001, Machinery Solutions, Inc. was retained to perform an independent study of the CS-P-B vibrations. The following discussion was obtained from their report, issued in September of 2001. Machinery Solutions, Inc. utilized seven transducers and acquired data from CS-P-B continuously while it was operating, and data was stored every 3 seconds. Orbit plots, spectrum plots, bode and polar plots, cascade/waterfall plots, overall amplitude plots, trend plots, XY graph plots, and tabular lists were utilized to analyze the data. The data obtained by Machinery Solutions, Inc., indicated that the vibration amplitudes during the run were much higher at the top of the motor than they were at the bottom of the motor. The amplitudes decreased even further on the pump. The spectrum plots showed that most of the vibration was occurring below running speed. They also showed that the low frequency vibration is a different frequency in each direction. The predominant peaks occur at approximately 870 cpm (less than one-half pump running speed) in line with discharge and at approximately 630 cpm (less than one-half pump running speed) perpendicular to discharge. The amplitude of each of these peaks varied significantly from second to second. The natural frequency of the pump-motor-piping structure was determined via impact testing prior to starting the pump. The natural frequencies were determined to be approximately 830 cpm in line with discharge and 670 cpm perpendicular to discharge. Such a vibration response is typical for vertical pumps. Machinery Solutions, Inc. concluded the following: Most of the vibration that is measured on the motor casing is due to excitation of the structural resonances of the motor/pump by turbulent flow. These structural resonances are poorly damped and can be easily excited. Most vertical pumps have similar types of behavior, and it is not necessarily problematic by itself. A problem occurs when a pump has a continuous forcing function whose frequency coincides with a resonance (i.e., running speed). The forcing function in this case is flow turbulence caused in large part by the S-curve in the piping just off the pump discharge. The flow through this area generates lateral broadband forces, due to elbow effects, that excite the resonances in a non-continuous fashion. This is why the amplitude swings so dramatically on the motor case (the location of vibration points lH and 5H). The system goes from brief periods of excitation to brief periods of no excitation. The discharge riser is also moving side to side from the same forces. Although the discharge piping configuration is both non-standard and less than optimum for this application, it poses no threat to the long-term reliability of either the pump or the motor. The only negative impact is on vibration levels relative to a generic standard. 2. 3 The balance condition of the motor and pump are acceptable with no corrective action required at this time. I The shaft alignment between the motor and the pump is acceptable for long-term operation.

NLS202501 1 Page 15 of9l Relief Request RP-02 Core Spray Pump B Vibration Alert Limits (Continued)

4.

There is no evidence of motor bearing wear Machinery Solutions, Inc. recommended the following actions: Create a new IST vibration data point configuration within the data collector database to use an overall level that is generated from spectral data above 950 cpm. This will eliminate the energy from the resonances from the data set and still allow for protection from bearing degradation, impeller degradation, and motor malfunctions. The only potential failure mode that could occur within this excluded frequency range would be a fundamental train pass frequency generated by a rolling element bearing. This frequency only occurs with increased bearing clearance. On vertical machines, this increased bearing clearance causes increased bearing compliance and the lX component will become larger. The lX change will be evident in the monitored data set. Continue to acquire the old data points with the low-frequency data "for information onlyto verify that the system response does not change. III. Attempts to Lower Vibration (Key Component No. 3) CNS installed additional pipe restraints during the preoperational period in order to reduce piping-induced vibrations. Testing on October 26 and21,1973, following the installation of these new supports, demonstrated significantly reduced vibrations. Low-frequency piping-induced vibrations continued, but with reduced amplitude following the installation of the pipe restraints. However, the issue resurfaced in the early 1990s when additional vibration points were recorded, more strict acceptance criteria were adopted for vibrations, and new technology was incorporated into the CNS vibration program. These new points were more influenced by the low-frequency piping-induced vibrations than the one or two points recorded in the 1980s. It was evident that the piping-induced vibrations were still prevalent with the CS-P-B pump. In 1993, a deficiency report was written to address increased frequency IST testing of CS-P-B due to vibration. It was suspected that the pump vibrations were piping induced. Preliminary investigation of the vibration issue concluded that cavitation at the CS test retum line throttle valve and/or restriction orifices was likely causing the elevated piping vibration in both CS System loops. Vibration testing of the CS piping confirmed this conclusion. To reduce these flow-induced vibrations, DC 94-046 was developed to replace the existing simple, single-stage orifices on both CS subsystem test return lines with multi-stage orifices. Post-installation testing with these multi-stage orifices demonstrated lower vibration levels on CS-P-A, but higher vibration levels on CS-P-B. A multi-hole single-stage orifice was fabricated and installed in the CS-P-B test return line (and later in the CS-P-A test retum line) with significantly improved results. Visual observation and 2.

NLS202501 1 Page 16 of9l Relief Request RP-02 Core Spray Pump B Vibration Alert Limits (Continued) vibration data collected during acceptance testing determined that CS-P-B pump vibrations had been reduced, but one direction (location lH in Figure 1) still demonstrated peak velocity reading in the alert range. The pump vibrations in the lH direction were occurring at frequencies much lower than the pump operating speed. The major vibration peaks were occurring at approximately 700 (cpm), while the pump speed is at 1780 cpm, indicating that the vibration was piping induced. It was also observed during acceptance testing that vibrations were minimal during operation in the minimum flow condition. IV. Spectral Analysis (Key Component No. 4) Figures 7 through 11 in this relief request show spectrum plots for CS-P-B, as well as spectrum trends. These plots show that the peak energy spikes for points lH and 5H remain below one-half pump running speed and that the pump vibration signature remains fairly uniform. Figure 12 shows that pump differential pressure is consistently acceptable. This data validates the analysis performed by Machinery Solutions, Inc., and the earlier conclusions that the elevated vibrations are piping induced, and not indicative of degraded pump perfornance. No pump or motor faults and/or degradation are evident in the spectral analysis for this pump. This test data also shows that the vibrations experienced remain in the region of the CS-P-B pump-motor-piping system natural frequency, at less than half the pump's operating speed. Vibrations occurring at these low frequencies are not expected to be detrimental to the long-term reliability of either the pump or the motor. Typical pump faults, i.e., impeller wear, bearing problems, alignment problems, shaft bow, etc., would result in measurable vibration response in frequencies equal to or greater than one-half of the pump's rururing speed. Such faults would also be evident in pump trends. However, the vibrations are being experienced below one-half pump operating speed, have existed since initial operation, and are not trending higher. Visual inspection by Machinery Solutions, Inc., in 2001 of the pump base plate, soleplate, and grout, identified no visible cracks or degradation. Further, they concluded that the balance condition and shaft alignment of the pump and motor were acceptable, and detected no evidence of motor bearing wear. A. Maintenance History The maintenance history for CS-P-B reflects that there have been no significant work items applicable to CS-P-B due to the low-frequency vibrations that have been experienced since the construction phase of the plant. A review of maintenance history for the CS-P-B pump and motor was performed. The search consisted of a historical review of CS-P-B pump and motor maintenance in addition to a more general search of CS System vibrational issues. This search identified that the pump and motor installed in the plant today is the same combination that was installed during the construction phase of the plant. Some of the key items reviewed are summarized below:

NLS20250l I Page 17 of9l 1 2. J 5 6 4. Relief Request RP-02 Core Spray Pump B Vibration Alert Limits (Continued) 1973: Additional supports installed on "B" CS System during pre-operational stage. As discussed previously, this resulted in lowering CS-P-B vibrations. January 1977: Yibration eliminator on "B" CS test line, CS-VE7, required tightening of wall plate bolts per Maintenance Work Request (MWR) 77-l-10. Bolts in pipe clamp were replaced and clamp was realigned. Design was determined to be adequate, but lock washers should be used to prevent recuffence of the problem. MWR 77-l-262 completed this action. April 1989 (Work Item [WI] S9-0269); November 1991 (WI9l-1507), February 1993 (MWR #92-2876): CS-P-B stator end turn bracing brackets inspected for stress corrosion cracking or unusual conditions such as loose bolts or bending. No cracks, loose bolts, or other unusual conditions were observed. March 1993: A magnetic particle examination of CS-P-B support attachment weld revealed an indication at Lug #5 of the pump support. The indication was ground out, repaired, and retested satisfactorily. The indication was very small and would not have affected the overall stiffness of the pump. In 2003, no recunence of this indication was identified. April 1993: Work Order #93-1631was initiated due to mechanical seal leakage. A complete inspection of the pump/motor was also completed. The pump was found with the keyway not properly aligned with the mechanical seal, causing the leakage. The impeller was found to have minor pitting at the base of the wear ring area. The pump casing and cover had minor erosion and pitting. No significant problems with the pump or motor were noted. July 1994: Bolt torque checked for lower end bell and lower bearing housing on CS-P-B motor due to a loose bolt found on the (A" RHR pump motor. No movement on lower bearing housing bolts. Movernent of lower end bell bolts were as follows: 1116 fTat on #1, 3,4, and 5 and no movement on#2,6,7, and8. These were very minor adjustments. Late 1994: DC 94-046 installs new orifices in CS-P-B test line. As previously discussed, this reduced piping deflections in the test line. Oil Samples (Dates: 09-22-95,10-22-95, ll-24-95,02-28-97,03-26-98,04 99,01-24-00, 12-26-00, 10-29-02,09-30-04, 01-05-05, 0g-14-06, 02-29-07,09-t4-07,02-1 I -08, 08-14-09, 02-lg-09,09-12-09, 02-09-10, 0g-25-10, 03-l I -1 1, 09-02-t1,t2-13-tt,03-02-t2,09-24-12,02-12-13,09-13-13,02-tI-14,09 14,2-13-t5,8-13-15,2-16-16,9-19-16, 2-14-17,9-15-17,2-t3-lg, g-15-19,2-13-19,2-lI-20,8-13-24\\: Periodic Oil Sample Analysis of the upper and lower motor bearings in accordance with Preventive Maintenance Program. Results of CS-P-B Motor oil analysis were satisfactory with no corrective actions required. Numerous Visual Motor Inspections completed satisfactory (i.e., January of 2002): Visual motor inspection satisfactory per Work Order #4199724. 7 8 9

NLS202501 1 Page l8 of91 Relief Request RP-02 Core Spray Pump B Vibration Alert Limits (Continued) 10. February 2003: Notification #10225272 identifred an indication approximately 3/8" on a CS-P-B integral attachment (CS-PB-AI). The indication is at the top of one of the small gusset supports where the gusset is welded to the cast pump bowl extension (different spot than the 1993 indication). Within Engineering Evaluation 03-030, the indication was determined to be on the gusset side of the weld and appears to be an incomplete fusion of the weld and not a service load-induced flaw. Poor accessibility was the most likely cause. Engineering Calculation 03-007 demonstrated that, even if the five minor gusset plates were ignored, the pump support is still qualified under the most severe design loads. 11 January 2005: Vendor motor inspection per work order 4476495. Motor condition found to be satisfactory for operation. 12 August 2014: Vendor motor inspection per work order 4896308. Testing/examination results demonstrated no indication of a degraded equipment condition or adverse trend. Two conditions were identified. Sludge/sediment was found in the upper motor bearing oil reservoir (Condition Report (CR) 2014-05077) and upper motor bearing oil leak from thermocouple (CR 2014-05121). 13 August 2024: Yendor motor inspection per work order 5412629. No potential operability or reliability concerns were identified. This search of the maintenance history, covering a time period of approximately fifty years, identified no significant maintenance or corrective actions that had to be implemented for the *B" CS pump and motor due to the piping-induced vibrations. Only minor indications were noted on the pump impeller and casing during the last significant motor/pump disassembly in 1993. No other documentation of pump/motor disassembly inspection results was found during this review. Oil analyses of the CS-P-B lower and upper motor bearing housings were found to be satisfactory for all the results documented since 1995 to the present. Wear metals, contaminants, additives, etc., were all at acceptable levels. The addition of pipe supports in 1973 and new orifices in the test lines were necessary modifications and were previously discussed. Other than these modifications, only minor corrections have been made with pipe andlor pump supports (tightening bolts, minor indication, etc.), none of which were found to be significant. Therefore, the maintenance history supports the basis of this relief request in that the piping-induced vibrations occurring on CS-P-B have not degraded the pump or motor in any way. B. Basis for Code Altemative Alert Values for Points lH and 5H By this relief request, NPPD is proposing to increase the absolute alert limit for vibration point 1H from 0.325 inls to 0.550 inls and vibration point 5H from 0.325 inls to 0.480 inls. The piping-induced vibration, which occurs at low frequencies, causes the overall vibration value for these two points to exceed the ASME OM Code absolute alert limit of 0.325 in/s in addition to the previously approved absolute alert limits of 0.400 inls from the 4th and 5th ten-year intervals, resulting in CS-P-B being on an increased test

NLS202501 1 Page 19 of91 Relief Request RP-02 Core Spray Pump B Vibration Alert Limits (Continued) frequency and unnecessarily resulting in resources being utilized to address the issue. The spectral data for all the previous incidences of exceeding the established alert limits have resulted in the same, consistent conclusion that the higher values were due to the historical, sporadic piping-induced resonant frequency that is not impacting the reliability of the pump. Several expert analyses and maintenance history reviews have shown that this piping-induced vibration has not resulted in degradation to the pump. Additionally, the overall vibration levels for these two vibration points have not degraded over the past -34.5 years. Therefore, it has been demonstrated that doubling the test frequency based on alert values of 0.325 inls or 0.4 inls does not provide additional assurance as to the condition of the pump and its ability to perform its safety function. The proposed alert value of 0.550 in/s for vibration point 1H and 0.480 in/s for vibration point 5H are reasonable as they represent an alternative method that still meets the intended function of monitoring the pump for degradation over time while keeping the required action level unchanged. The proposed new alert values will encompass the magnitude of all the historical values for vibration points lH and 5H since April of 1990 with only a slight margin of approximately 0.03 inls (reference Figures 2b and 3b). A recording of a value into one of the new alert ranges would require NPPD to place the comprehensive pump test on a doubled test frequency and to evaluate the pump performance to determine the cause of the reading. It is expected that a small amount of degradation occurring in the pump or a slight increase in the magnitude of the piping-induced vibration would be quickly identified with these new parameters. Also, regardless of the values recorded, CNS will continue to monitor the spectral data of every CS-P-B test in which vibrations are taken, which is above and beyond the requirements of the ASME oM Code. The new alert limits will still allow for early detection of pump degradation or piping-induced vibration increases prior to component failure, while the required action absolute limit will remain at the code value of 0.700 inls. Therefore, the intent of the code will be maintained. Conclusions Several expert evaluations have documented that no internal pump or motor degradation is occurring due to the piping-induced vibration, which has been present since the pre-operational testing time period. The available vibration data over the past -34.5 years and differential pressure data over the past -30 years supports this fact as essentially no degradation has been indicated. A maintenance history review and review of oil analyses results further supports these conclusions. Based on this information, CNS concludes that doubling the test frequency for CS-P-B based on alert limits of 0.325 inls and/or 0.400 inls for vibration points lH or 5H, does not provide additional information nor does it provide additional assurance as to the condition of the pump and its ability to perform its safety function. Testing of this pump on a doubled test frequency, based on these previously utilized alert limits, also places an unnecessary burden on CNS resources.

NLS20250l 1 Page 20 of91 Relief Request RP-02 Core Spray Pump B Vibration Alert Limits (Continued) All four key components discussed in NUREGICP-}L1? have been addressed in detail, supporting the alternative testing recommended in this relief request. CNS concludes that CS-P-B is operating acceptably and will perform its safety function as required during normal and accident conditions. The increased alert limits proposed for vibration points lH and 5H in this relief request will continue to assure long-term reliability of CS-P-B. During the performance of CS-P-B inservice comprehensive pump testing, or any other time vibrations are recorded to determine pump acceptability (i.e., post-maintenance testing, other periodic testing, etc.), pump vibration shall be monitored in accordance with ISTB-3510(e) and ISTB-35a0(a). The acceptance criteria for vibration points 2H, 3H, and lV will follow the criteria specified in ISTB Table ISTB-5121-1. The acceptance criteria for vibration point lH will have an absolute alert limit of 0.55 inls and the acceptance criteria for vibration point 5H will have increased absolute alert limit value of 0.480 in/s. The absolute required action limits for all points will continue to be 0.700 fu/s in accordance with ISTB Table ISTB-5 I 2 I - 1. The absolute alert and required action limits for all vibration points associated with CS-P-B are summarizedinthe table below. Absolute Vibration Acceptance Criteria for CS-P-B: Vibration Parameter Acceptable Range Alert Range Required Action Range IH < 0.550 in./sec. >0.550 in./sec. >0.700 in./sec. 5H < 0.480 in./sec. > 0.480 in./sec. >0.700 in./sec. IV < 0.325 in./sec. >0.325 in./sec. >0.700 in./sec. 2H < 0.325 in./sec. >0.325 in./sec. >0.700 in./sec. 3H < 0.325 in./sec. >0.325 in./sec. >0.700 in./sec.

6.

Duration of Proposed Alternative This proposed alternative will be utilized for the entire Code of Record interval that uses Ihe2022 Edition of the ASME OM Code, begiruring on March 1,2026, and ending on February 28th, 2050.

7.

Precedents A version of this relief request was previously approved for the fifth ten-year interval at CNS as Relief Request RP-07 (CAC NOS. MF591l, MF5913, MF5914, MF5915, MF5916, MF5917, MF5918, MF59l9, MF5920, MF5921, MF5922, MF5923, MF5924, MF5925, and MF5926,

NLS2025011 Page21 of91 Relief Request RP-02 Core Spray Pump B Vibration Alert Limits (Continued) February 12,2016), and for the fourth ten-year interval at CNS as Relief Request RP-07 (TAC Nos. MC8 8 37, MC897 5, MC897 6, MC897 7, MC8978, MC8979, MC8980, MC898 1, MC8989, MC8990, MC8991, and MC8992, June 14,2006). Byron Station previously received approval for an absolute alert value of 0.55 inls for a similar pump resonant issue (reference MLI 6043A1 5 1, dated February 22, 2016).

NLS202501 l Page22 of91 Relief Request RP-02 Core Spray Pump B Vibration Alert Limits (Continued) CS-P-B Figures Figure Number Description Attach.2 Page Number 1 CS-P-B Vibration Monitoring Points 23 2a CS-P-B Vibration Point lH from November 1996 to the Present 24 2b CS-P-B Vibration Point lH from April 1990 to the Present with 0.55 inls Alert Value 25 2c Trend of Vibration Point lH with Data Below One-Half Pump Running Speed Filtered from February 2020 to the Present 26 3a CS-P-B Vibration Point 5H from November 1996 to the Present 27 3b CS-P-B Vibration Point 5H from April 1990 to the Present with 0.48 in/s Alert Value 28 3c Trend of Vibration Point 5H with Data Below One-Half Pump Running Speed Filtered from February 2020 to the Present 29 4a CS-P-B Vibration Point lV from November 1996 to the Present 30 4b CS-P-B Vibration Point lV from April 1990 to the Present 31 5a CS-P-B Vibration Point 2H from November 1996 to the Present 32 5b CS-P-B Vibration Point 2H from April 1990 to the Present 33 6a CS-P-B Vibration Point 3H from November 1996 to the Present 34 6b CS-P-B Vibration Point 3H from April 1990 to the Present 35 7 Spectral Trend for Vibration Point lH 36 8 Spectral Trend for Vibration Point 5H 37 9 Spectral Trend for Vibration Point lV 38 10 Spectral Trend for Vibration Point 2H 39 ll Spectral Trend for Vibration Point 3H 40 t2 CS-P-B Differential Pressure since January 1995 to the Present 41

NLS2025011 Page23 of9l Relief Request RP-02 Core Spray Pu-p B Vibration Alert Limits (Continued) IV sn--{> sH+ DISCHARGE 1H 2H 62C5101A Figure I CS-P-B Vibration Monitoring Points

• -sucrto x

NLS2025011 Page 24 of91 0.67

• 0.61 -

0.55 - 0.49 - £! 0.37 0.1l 11 /06t1 996 Relief Request RP-02 Core Spray Pump B Vibration Alert Limits (Continued) CS-P-B V ibration PGint '1 H" Frnm ~lo ember 1996 to the Present 11* 11*11111111 1111111111

• 111111111111*111111111111111 111111111111111 1111111 06/22J2002 091.2lll.2 13 05t00f2019 12119i2024 Date Figure 2a CS-P-B Vibration Point lH from November 1996 to the Present

NLS2025011 Page 25 of91 [ V ib (1H) (in/ sec) 0 14f19.90 Relief Request RP-02 Core Spray Pump B Vibration Alert Limits (Continued) - V i (1H) Alert .A.. Vlb (1 H) Action CS-P-S V ibration Point 1H Fram A pril 1990tothe Present w ith 0.55 inJs A lert V alue 03122J1997 12i'Z7J201)4 02/0412011 01i'1212018 ate Figure 2b 12t19l202 CS-P-B Vibration Point lH from April 1990 to the Present with 0.55 in/s Alert Value

NLS2025011 Page 26 of91 Relief Request RP-02 Core Spray Pump B Vibration Alert Limits (Continued) 14.83-1KHZ t:1119!2024 1*52 25 PM Roe.Ce 0.526V-OG Pl<*0.526 LOAD* 100.00 RPM*t7800 (29.67HZ) ~~~~~..A.-=,,,._~.a.,._-,--....1.-__ .....___~........-~__.__-----.-----...--~----.----------, F-669.38 Date 13-FEB-20 16-MAY-20 1 l-AUG-20 10-NOV-20 24-FEB-21 18-MAY-21 18-AUG-21 15-FEB-22 3204) Frequencv (CPM) List of Trend Points Station: REACTOR BUILDING Machine: CS-MOT-B CORE SPRAY PUMP MOTOR B Meas Point: lH MOTOR UPPR HORIZONTAL SOUTH (H0l) Parameter: 14.83 - lKHZ (PK Velocity in In/Sec) Time Value Date Time 12:29 0.122 22-MAY-22 3:49 14:41 0.125 21-NOV-22 11 :58 21:30 0.127 14-FEB-23 12:33 11 :36 0.122 l 7-MAY-23 10: 19 3: 18 0.104 14-NOV-23 13:06 14:41 0.127 14-MAY-24 12:22 14:20 0.106 14-AUG-24 16:43 10:15 0.109 19-DEC-24 13:52 Early Warning Limits --- 0.130 Alert Limit Values ---0.300 Fault Limit Values --- 0.700 Figure 2c Value 0.116 0.115 0.117 0.120 0.114 0.135 0.101 0.110 Ont0376 ""'"0378 Trend of Vibration Point lH with Data Below One-Half Pump Running Speed Filtered from February 2020 to the Present

NLS2025011 Page 27 of 91 Relief Request RP-02 Core Spray Pump B Vibration Alert Limits (Continued) Vi 'SH) Action CS-P-8 Vibration Point 5H From Na ember 1996 t th.e Present .10--------------.... -----~-~.... --.............. ________ _ 0.67 - .28 - 0.25 -1 .22 - 0.19 11 >'06t19.96 OOJ2212002 02lOSJ20G8 0912012 13 05£0,&12 19 12119,2024 Date Figure 3a CS-P-B Vibration Point 5H from November 1996 to the Present

NLS2025011 Page 28 of 91 j Vi (SH) (in/sec) D.64 - 0.58 - .52 - T Relief Request RP-02 Core Spray Pump B Vibration Alert Limits (Continued) Vib :-SH) lert £ Vib (5H) ction CS-P-B Vibration Point SH From April 1990 to the Present *1ith. 0. S iru's. Alert Value Cf MW I fl C SC C 03/22J1997 022712004 21'11412011 111212 1 S ate Figure 3b 12/1912024 CS-P-B Vibration Point SH from April 1990 to the Present with 0.48 in/s Alert Value

NLS2025011 Page 29 of91 Relief Request RP-02 Core Spray Pump B Vibration Alert Limits (Continued) 1483*1KHZ 12119/2024 1-53-42 f't.1 RoLte 0388V-OG Pl<*0.388 LOA0*100.00 RPM* 1780.0 (29.67Hz) o~1/4..:.:vl ~ -~~~,A~~-

• ~~----&..-~=--=-=-.j,.'-s-...--i-------.......... -----.---'----

0 8010 Date 13-FEB-20 16-MAY-20 l l-AUG-20 10-NOV-20 24-FEB-21 18-MAY-21 18-AUG-21 15-FEB-22 320<0) Frequency (CPM) List of Trend Points Station: REACTOR BUILDING Machine: CS-MOT-B CORE SPRAY PUMP MOTOR B Meas Point: 5H MOTOR UPPR HO RIZO NT AL WEST (H05) Parameter: 14.83 - 1 KHZ (PK Velocity in In/Sec) Time Value Date Time 12:31 0.218 22-MAY-22 3:51 14:43 0:242 21-NOV-22 12:00 21:30 0.217 14-FEB-23 12:46 11 :38 0.237 l 7-MAY-23 10:20 3: 18 0.233 14-NOV-23 13:06 14:41 0.252 14-MAY-24 13:08 14:23 0.225 14-AUG-24 12:23 10:16 0.244 19-DEC-24 14:44 Early Warning Limits --- 0.265 Alert Limit Values ---0.300 Fault Limit Values --- 0.700 Figure 3c Value 0.252 0.216 0.216 0.218 0.114 0.214 0.230 0.201 Trend of Vibration Point SH with Data Below One-Half Pump Running Speed Filtered from February 2020 to the Present

NLS2025011 Page 30 of 91 0.65-o_c9 _ 0.53 - .47- ~

0. 1

.£ 0.35 - 0.29 - 11 lll611996 I Relief Request RP-02 Core Spray Pump B Vibration Alert Limits (Continued) ib ( 1 V) Alert £ Vib (1\\/) Action CS-P-B Vibration Point "'1V-From November 1996 to the Present 06J22J2002 0912012013 05J06f.2019 12119./202 Date Figure 4a CS-P-B Vibration Point lV from November 1996 to the Present

NLS2025011 Page 31 of91 .68 0.62-L .5 - 0.32--~ .26- .2 - 0.08, 0411 1000 Relief Request RP-02 Core Spray Pump B Vibration Alert Limits (Continued) Vib (1\\/) Alert ,6. Vib 1 V ) Actilm Forecasting CS-P-S Vibration Point "'*1V" From pril 199 t the Present 021271200 02f04.t2011 01 * *121.2018 ate Figure 4b CS-P-B Vibration Point lV from April 1990 to the Present 1211'9/2 :24

NLS2025011 Page 32 of91 0.5-8 . 54 - 0.50 - 0.42 - O.JB ~

0. 0 -

0.26-11106(1996 Relief Request RP-02 Core Spray Pump B Vibration Alert Limits (Continued) Vib (2H) Alert (2H) A.ction Forecasting CS-P-B Vibration Point H From t* o ember 1900tothe Present 0612ZJ2002 02.1'051200.8 09.1'20l201l OSJ00/2019 Date Figure Sa CS-P-B Vibration Point 2H from November 1996 to the Present 12119/2024

NLS2025011 Page 33 of 91 (2H) (in/sec) 0.70-0.66- .62 -.. . ss- .54-0.50-04[14/1990 Relief Request RP-02 Core Spray Pump B Vibration Alert Limits (Continued) .. Vib (2H) Action Forecasting CS-P-S V ibration Point .., From pril 100 t the Present 0512:2/-1 997 02l2712U 02{04.1'2011 01/1212018 ate Figure Sb CS-P-B Vibration Point 2H from April 1990 to the Present 12)'191202

NLS2025011 Page 34 of 91 fi Vib (JH) (in 'sec) 0.65-0.59 - 0.53- . 7 - 0.41 * .£ 0.35-I .29' 1H06t1'996 Relief Request RP-02 Core Spray Pump B Vibration Alert Limits (Continued) Vib (lH) Alert ~ V ib (3H) Acti~n CS-P-B Vtbratic,n Pn,int '3H From P ov ember 1996 to the Present M: ? C CC rec JREf 111 II I l-11111111 1111111111

• 1 H N Ill I II I 111111111111111 111111 Ill II II IHIIII Ill OOJ2212002 02l0&'200B 09t20/2013 OS/06/2019 1211.9/202 Date Figure 6a CS-P-B Vibration Point 3H from November 1996 to the Present

NLS2025011 Page 35 of 91 fji Vi (JH) (inJsec) Relief Request RP-02 Core Spray Pump B Vibration Alert Limits (Continued) V ib (3H) A lert .A. V ib (JH) Actio~ ----. Fore~ asting CS-P-6 Vibration Point 3H From pril 1990 to the Present .70....,....... --..---.-----... --..c...,.cn****..... WaEa1W1111i6MiaEia6illlililillif""".....,.1,1,1,QWIM6lilMIMtlllilililWilllWiMil1M111....,.~ 0.66 - u 0.21"' .17 - .13 - .09 - 0.05 0 1 1990 97 0.21'27"'2004 Ozt04l.2011 0111212018 1211912024 Date Figure 6b CS-P-B Vibration Point 3H from April 1990 to the Present

NLS2025011 Page 36 of 91 ~ c:: i 0.1g ~ 0.005 Relief Request RP-02 Core Spray Pump B Vibration Alert Limits (Continued) C NS Sun,eft n Pro<:4tdu1e-s f'tU1'\\ t SP's / 10216939 TORUF>f>A TA<. CNS Su"Vftlllta,-,.e.a: P ~u.r ...._ro...,.. S?"s 1021693'9 lH ~ f.OTOR U?P ~ t..oN.tZOr'<rAL SOU"l"H f'HOtJ 12.11912024 t 5-2 25 Pti.4 0$26Y..00 ~*052 i..0..C..0*10000 RPM *t7800 (29& I-tr ) Multiple Route S oectra "2T"""------------------------T""0.38 211~/202'.2' 0-1'--""""......,.,.,_,__>-r-~..,.__~--r~------.-~~-..------,-------< 0 10000 20000

30000 40000 50000 Frequency (CPM)

Figure 7 Spectral Trend for Vibration Point lH

NLS2025011 Page 37 of 91 Relief Request RP-02 Core Spray Pump B Vibration Alert Limits (Continued) C N S Su rveillance Procedures rbm I SP's J 102 16939 SH - M O TO R UPPR H ORIZONTAL V.'E.S T (HOS} ~ S eu ~ "'K>a P'~ u "lt* "'Dm SP'"'s. 102't6'S.39 $ 1,-1:

• J.AOTOq UP P R. ~

JZ Or-IT.r...t.. '".tE:S 7 (t-ol:0 5 ) 1211912024 1 53:4 2 PM Route 0.388 V-OG Pk

• 0.388 LOA0
• 100 00 RPM
• 1780.0

( 29.67 Hz) l'..4u1tso1e Route Soectra ~---- -------------------~ 0.25 30000 Frequency (C P M) Figure 8 Spectral Trend for Vibration Point SH

NLS2025011 Page 38 of 91 0,o Relief Request RP-02 Core Spray Pump B Vibration Alert Limits (Continued) C NS Surveillance Procedures.rbm I SP-s / 10216939 1 V - M O T O R UPPR AXIAL (V01 ) c,,.s s.. 30000 Frequency (CPM) 1 2/19/2024 1 52*03 PM Route 0182 V-00 Pk - 0.178 LOAD

• 100.00 RPM*1780.0 (29.67 Hz) ul e R oute Sceelr T'""-"------------------------,-0,o 0 04 L

2Jt3!2t)'20 20000 30000 "0000 socoo l'reQtsOOC'Y (C P I) Figure 9

NLS2025011 Page 39 of 91 ~ 0.07 g ~ 0.035 Spectral Trend for Vibration Point 1 V Relief Request RP-02 Core Spray Pump B Vibration Alert Limits (Continued) CNS SuNeilfance Procedures.rbm J SP-s 1 102169:39 2H - M O TOR L 'NR HORJZONT AL SOUTH(H02} 30000 Frequency (C PM) CNS S u..... -. ,i.e,a P~du res l'C>.m s 0 s 102 tf!,933 2~

• t.-10-oq t. *VR f-iORIZONTAL SOVTH!'l-<f21 L__

_..__ __ ____ l L -- 20000 30000 <<lOOO Frequency (CPM) 12 119/2024 1.52*55 PM Route 0.140V.DO Pk* 0."140 LOA0*10000 RPM*1780.0 ( 29.67 HJ:) Multiple Route S pectra

NLS2025011 Page 40 of 91 008 "2 £ ff ! 0 00 ~ 0. t 14 g ~ 0.076 Figure 10 Spectral Trend for Vibration Point 2H Relief Request RP-02 Core Spray Pump B Vibration Alert Limits (Continued) RX-CORE SPRAY PUMP MOTOR B CS-MOT-B -3H MOTOR LWR HORIZONTAL WEST (H03) C N S S u rveillance Proc-edur-e s.rbm ~ SP"s J "1 02-i 6 939 3 H - M O TOR L 1JVR. H O R IZONTAL '...vES T ( H 03) Freque n cy (CPM) CNS S ~ lV9 J\\e. P~u-.* "'Om SP-* 102153 3'3 3._. - MO'TOR L\\.V'l ~qtZON,AL \\.VE..S~ "1-Q3 1 -,--- ---------- ----------,--0.11;) 11/21/20Z2 2124'2021 20000 30000 40000 Frequency (CPM) ~2r t9~~; ~.::14 P~t Pll' - 0"1 86 L OAD - 1 00 00 RPM 1 7 80 0 (29 6 7 Hz) Multiple Route Spectra

NLS2025011 Page 41 of 91 Figure 11 Spectral Trend for Vibration Point 3H Relief Request RP-02 Core Spray Pump B Vibration Alert Limits (Continued) [II iff Press (dP) Lo,, Action Diff P7°ess (dP) (;-id) ---~ Diff Press ( P) High Actio-;;--. Forec~sting-CS-P-B Differential Pressure From January 1.995to,the Present tR f

r

• a f

C R 3T111 283.c

• 277.601..---............_ __ ____

271.70

• 265.80 01100/1995 01/0212001 1ZOOl2CNJ6 12J.26t.2 12 1212lt.2018 1211912024 Date Figure 12 CS-P-B Differential Pressure Since January 1995 to the Present

NLS20250l I Page 42 of97 I Relief Request RV-01 HPCI Solenoid Operated Drain Valve Testing Proposed Alternative in Accordance with 10 CFR 50.55a(z)(1) Alternative Provides Acceptable Level of Quality and Safety ASME Code Comnonent(s) Affected Valve Class Category System HPCI-SOV-SSV-64 2 B HPCI HPCI-SOV.SSV-87 2 B HPCI Appiicable Code Edition and Addenda ASME OM Code 2022Edition

Applicable Code Requirement

ISTC-3300 Reference Values - Reference values shall be determined from the results of preservice testing or from the results of inservice testing. ISTC-3310 Effects of Valve Repair, Replacement, or Maintenance on Reference Values - When a valve or its control system has been replaced, repaired, or has undergone maintenance that could affect the valve's performance, a new reference value shall be determined or the previous value reconfirmed. ISTC-3500 Valve Testing Requirements - Active and passive valves in the categories defined in ISTC-I300 shall be tested in accordance with the paragraphs specified in Table ISTC-3500-1 and the applicable requirernents of ISTC-S100 and ISTC-5200. ISTC-3560 Fail-Safe Valves - Valves with fail-safe actuators shall be tested by observing the operation of the actuator upon loss of valve actuating power in accordance with the exercising frequency of ISTC-35 10. ISTC-5151 Valve Stroke Testing - (a) Active valves shall have their stroke times measured when exercised in accordance with ISTC-3500. (b) The limiting value(s) of full-stroke time of each valve shall be specified by the Owner. (c) Stroke time shall be measured to at least the nearest second. ISTC-5152 Stroke Test Acceptance Criteria - Test results shall be compared to reference values established in accordance with ISTC-3300, ISTC-3310, or ISTC-3320. 2. 3. ISTC-5153 Stroke Test Corrective Action.

NLS202501 1 Page 43 of91 Relief Request RV-01 HPCI Solenoid Operated Drain Valve Testing (Continued)

4.

Reason for Request

Pursuant to 10 CFR 50.55a, o'Codes and Standards," paragraph (z)(l), relief is requested from the listed requirements of the ASME OM Code. The proposed alternative would provide an acceptable level ofquality and safety. The HPCI turbine and exhaust steam drip leg drain to gland condenser (HPCI-SOV-SSV-64) and HPCI turbine and exhaust steam drip leg drain to equipment drain isolation valve (HPCI-SOV-SSV-87) have an active safety function in the closed position to maintain pressure boundary integrity of the HPCI turbine exhaust line. These valves serve as a Class 2 to non-code boundary barrier. These valves are rapid acting, encapsulated, solenoid-operated valves. Their control circuitry is provided with a remote manual switch for valve actuation to the opan position and an auto function which allows the valves to actuate from signals received from the associated level switches HPCI-LS-98 and HPCI-LS-680. Both valves receive a signal to change disc position during testing of drain pot level switches. However, rernote position indication is not provided for positive verification of disc position. Additionally, their encapsulated design prohibits the ability to visually verifu the physical position of the operator, stem, or internal components. Modification of the system to verify valve closure capability and stroke timing is not practicable nor cost beneficial since no commensurate increase in safety would be derived.

5.

Proposed Alternative and Basis for Use From 1998 to July of 2016, CNS performed a robust exercise test for these two valves that verifies obturator movement on a quarterly basis. July of 2016, the frequency of this testing has been once every 6 months in accordance with an approved relief request for the 5th ten-year IST Interval. In 2001, this test identified some leakage past HPCI-SOV-SSV64 and the valve was removed and refi.rbished. For the past -24 years, the exercise test has been completed without any issues. This test is accomplished through the performance of surveillance procedure, 6.HPCI.204, HPCI-SOV-SSV64 and HPCI-SOV-SSV87IST Closure Test. WithHPCI not in operation, a demineralized water source is utilized to verifu that HPCI-SOV-SSV64 opens when level switch HPCI-LS-680 (turbine exhaust drain pot high level) trips, allowing level in the gland seal condenser to start to rise due to water flow through HPCI-SOV-SSV64. After HPCI-LS-680 resets and HPCI-SOV-SSV64 closes, the gland seal condenser level is verified to be steady. Similarly, CNS verifies that HPCI-SOV-SSVS7 opens when level switch HPCI-LS-98 (turbine exhaust drip leg high) trips, allowing the observation of water flow to a floor drain from a drain pipe downstream of HPCI-SOV-SSV87. After HPCI-LS-98 resets and HPCI-SOV-SSV87 closes, CNS observes the drain pipe downstream of HPCI-SOV-SSV87 for gross leakage past the valve. Therefore, CNS verifies valve obturator movement for both valves open and closed while simultaneously verifying the calibration of two level switches. Typically, tests that involve hooking up pressure sources and various amounts of test tubing are not performed on a quarterly basis due to their complexities (i.e. local leak rate tests). In addition, each time this "quarterly" test has been performed, HPCI unavailability time (-1.5

NLS20250I I Page 44 of97 Relief Request RV-01 HPCI Solenoid Operated Drain Valve Testing (Continued) hours) is consumed in addition to some minor radiological dose. Finally, this exercise test is actually a much better method of determining the valve's operational readiness than a quarterly fast acting stroke time test would have been. Therefore, based on the complexities of the test, consuming unnecessary HPCI unavailability time and personnel radiation exposure, the exceptional test history dating back to 2001, and the fact that this is a robust test that verifies obturator movement, CNS proposes to exercise each valve to the full closed position, as described, on a 6 month basis. ln addition to performing this robust exercise test every 6 months, each solenoid valve will be disassembled and examined for degradation on a periodic basis per the Preventative Maintenance Program. The valve body, insert, piston, plunger/stern assembly, and stem spring will all be examined per criteria outlined in surveillance procedure 6.HPCI.404. In addition, continuity and the physical condition of the coil will also be checked. The valve and/or valve parts will be refirbished and/or replaced, as necessary, based on this examination. This maintenance shall be performed at an optimized frequency, not to exceed 48 months (2 cycles). The purpose of this enhanced preventative maintenance is to ensure the long term reliability of the components and to monitor for internal degradation. This is consistent with NUREG 1482, Section 4.2.3. The 6 month exercise tests will ensure that the valves are operational and will fulfill their safety function when called upon. The frequency of the preventative maintenance (PM) task was developed after reviewing the maintenance and test histories for these two solenoid valves and after reviewing the Electric Power Research Institute (EPRI) recommendations for PMs on solenoid valves. The maintenance history for these valves since 2005 is documented in Table 1. A review of this data demonstrates that each valve has had two examinations that resulted in minor issues resulting in the replacement of parts (March of 2011 and April of 2014 for HPCI-SOV-SSV64; April of 2012 and April of 2014 for HPCI-SOV-SSV87). For these cases, the PM was doing its job by identifying parts that had minor issues and replacing them prior to them becoming a major issue and impacting the safety function of the valve. The exercise testing performed prior to and after these examinations was completed with acceptable results. As long as the exercise testing of the valves continues to demonstrate acceptable performance and the examination PMs do not identify any major issues that could have impacted the closure safety function, then the maximum frequency of 48 months may be utilized for these HPCI PMs. The maximum frequency of 48 months (2 cycles) is conservative when comparing this frequency to the EPRI PM recommendations. The EPRI recommended task for elastomer replacement and internal inspection of a solenoid valve is 5 years for a severe environment and up to ten years for a mild environment. CNS considers the location of these valves to be a severe environment, so the maximum frequency allowed by CNS would be one year less than what is recommended by EPRI. The frequency will be maintained through the CNS work management system and the PM process. A maintenance plan has been established with the necessary tasks required to satisfy the PM. A PM work order with these required tasks is automatically created well ahead of the scheduled due date and is scheduled based on the CNS work schedule process. Any frequency changes must be approved by the IST Engineer.

NLS202501 I Page 45 of91 Relief Request RV-01 HPCI Solenoid Operated Drain Valve Testing (Continued) The monitoring of these valves will be done by tracking the proposed six-month exercise testing and the results of the internal examinations. As was previously described, CNS has had excellent results with the exercise tests. Based on internal valve degradation, October of 2001 was the last time one of these valves (HPCI-SOV-SSV64) failed its closure acceptance criteria. For clarification purposes, however, there was a system issue in June of 2002 in which foreign material was causing HPCI-SOV-SSV64 to leak. An intemal examination identified that there was foreign material found under the valve disc of HPCI-SOV-SSV64, but the valve itself, was examined and found to be in an acceptable condition. The CNS corrective action program addressed the issue and no other foreign material issues have impacted the closure function of these valves since then. Therefore, no intemal valve degradation issue has impacted the closure function of these components since October of 2001 and no system issue has impacted the closure function of these components since June of 2002. The frequency of the PMs is optimized by balancing the component reliability with the correct PM frequency. The goal is to ensure that the solenoid valves continue to perform their closure function in a reliable manner without performing the intemal examination PMs too frequently. As long as the PM ensures that any minor issue is taken care of prior to it becoming an issue with the closure function of the valve meeting iis acceptance criteria, then the frequency is set at an acceptable duration. This, in conjunction with acceptable exercise tests, justifies the acceptability ofthe frequency. If the exercise testing results in a failure of the closure acceptance criteria of one of the solenoid valves, or the examination PM of one of the solenoid valves identifies a significant component issue that may have resulted in the respective valve not being able to perform its closure function, then the examination frequency of both solenoid valves shall be moved from 48-month frequencies to 24-month frequencies. From this point, two periodic examinations would have to be performed and completed satisfactorily at the 24-month frequency prior to returning the frequency to the 48 month frequency. In conclusion, the PM was developed based on a review of the maintenance and test history results, and review of EPRI recommendations. The existing frequency will be monitored as acceptable as long as the exercise testing is completed satisfactory and the internal examinations are either satisfactory or identiff parts for replacernent prior to when the parts issue would have caused a failure with the closure exercise testing. The frequency of internal examinations will be reduced from 48 months to 24 months for both valves if one valve were to fail its acceptance criteria for the closure exercise testing or if the findings of an internal examination of one of the valves results in the determination that it would not have met its closure function. Two successful examinations at the 24-month frequency would be required in order to retum the PM(s) to a 48 month frequency. This is how the frequency of the preventive maintenance task of disassembly, inspection, and refurbishment was developed, and how it will be maintained, monitored, and optimized, if approved. The robust 6 month exercise testing and the enhanced preventative maintenance will provide an adequate indication of valve performance and will continue to provide an acceptable level of quality and safety. Therefore, pursuant to 10 CFR 50.55a(z)(1), NPPD requests relief from the specific ISTC requirements identified in this request.

NLS20250r l Page 46 of 9I Relief Request RV-01 HPCI Solenoid Operated Drain Valve Testing (Continued)

6.

Duration of Proposed Alternative This proposed altemative will be utilized for the entire Code of Record interval that uses the2022 Edition of the ASME OM Code, beginning on March 1,2026, and ending on February 28th, 20s0.

7.

Precedents This relief request was approved for the fifth ten-year interval at CNS as RV-01 (CAC NOS. MF59l l, MF5913, MF5gl4, MF5gl5, MF5gl6, MF5gl7, MF5glg, MF5glg, MF5g20, MF5g2l, MF5922,MF5923,MF5924, MF5925, and MF5926, February 12,2016). A version of this relief request was previously approved for the fourth ten-year interval at CNS as Relief Request RV-01, Revision 1 (TAC NO. ME7021, August 28,2012) andRevision0 (TAC Nos. MC8837,MC8975, MC8976,MC8977, MC897g, MCggTg, Mcggg0, Mcgggl, Mcgggg, Mcggg0, MCgggl, and MC8992, June 14, 2006). A version of this relief request was previously approved for the fifth ten-year interval at Dresden Nuclear Power Station as Relief Request RV-23H (TAC Nos. ME9865, ME9866, ME9869, ME9870, ME987l, and ME9872, October 31,2013). Table 1: Maintenance histories for HPCI-SOV-SSV64 and HPCI-SOV-SSV87 HPCI-SOV-SSV64 HPCI-SOV-SSV87 02-10-05: Visual exam satisfactory (PM work order #4363336) 02-10-05: Visual exam satisfactory (PM work order 14363336) N/A 06-21-05: Replaced valve at same time as non-essential valve, HPCI-SOV-SSV88, was replaced. Valves are in close proximity. New valve allows parts to be procured. (Corrective Maintenance [CM] work order

1. 4211944) ll-7-06: Visual exam satisfactory (PM work order #4446767) l1-14-06: Visual exam satisfactory (PM work order #4446767\\.

03-18-08: Visual exam satisfactory (PM work order #4569097\\ 03-18-08: Visual exam satisfactory (PM work order #4569097) 08-19-09: Visual exam satisfactory (PM work order l*4626047') 08-19-09: Visual exam satisfactory (PM work order #4626047) 03-21-11: Valve replaced for parts reasons with a valve upgrade to match that of HPCI-SOV-SSVS7 (CM work order #4791033\\ 03-22-11: Visual exam satisfactory (PM work order #4750715) 04-24-12: Visual exam satisfactory (PM work order #4803767) 04-25-12: Seat plug on the bottom was found curled around the edges and was replaced. This issue did not impact the valve's closure

NLS202501 1 Page47 of9l function as the previous closure testing was performed successfully (PM work order

1. 4803767) 4-23-13: Visual exam satisfactory (PM work order #4895831).

04-23-13: Visual exam satisfactory (PM work order #4895831). 4-22-14: Plunger found slightly corroded and stem assembly was scored in the seating area. Both parts were replaced. Did not impact the valve's closure function as the previous closure testing was performed successfully. (PM work order #4938492) 4-22-14: Insert showed minor erosion/corrosion and plunger/stem has a small groove around seating area. Both parts were replaced. Did not impact the valve's closure function as the previous closure testing was performed successfully. (PM work order #4938492\\ 2-10-15: Visual exam satisfactory (PM work order 5003464). 2-10-15: Visual exam satisfactory (PM work order 5003464). 09-26-16: Visual exam satisfactory @M work order 5l2l99l) 09-26-16: Visual exam satisfactory (PM work order 5l2l99l) 10-24-18:. Visual exam satisfactory @M work order 5209525) l0-24-I8: Visual exam satisfactory (PM work order 5209525\\ 10-06-22: Visual exam satisfactory (PM work order 5381203) 10-06-22: Visual exam satisfactory (PM work order 5381203)

NLS20250t I Page 48 of91 I Relief Request RV-02 Main Steam Safety Relief Valve Testing Proposed Alternative in Accordance with 10 CFR 50.55a(zX1) Alternative Provides Acceptable Level of Quality and Safety ASME Code Component(s) Affected Valve Class MS.RV-7IARV 1 MS-RV-71BRV I MS-RV.7ICRV 1 MS-RV-7IDRV 1 MS-RV-7IERV I MS.RV-7IFRV 1 MS-RV-71GRV 1 MS-RV-7IHRV

1 Applicable Code Edition and Addenda

ASME OM Code 2022Bdition

Applicable Code Requirement

Category BIC BIC BIC B/C B/C BIC BIC BIC System MS MS MS MS MS MS MS MS 2. 3. ISTC-5240 - Safety and Relief Valves. Safety and relief valves shall meet the inservice test requirements of Mandatory Appendix I. ASME OM Code Mandatory Appendix I, "lnservice Testing of Pressure Relief Devices in Light-Water Reactor Nuclear Power Plants," Section I-1320, "Test Frequencies, Class I Pressure Relief Valves." ASME OM Code Mandatory Appendix I, I-3310 Class 1 Main Steam Presswe Relief Valves with Auxiliary Actuation Devices. Tests before maintenance or set-pressure adjustment, or both, shall be performed for (a), (b) and (c) in sequence. The remaining shall be performed after maintenance or set-pressure adjustments:

a. visual examination;

NLS20250t I Page 49 of91 Relief Request RV-02 Main Steam Safety Relief Valve Testing (Continued)

b. seat tightness determination, if practicable;

c. set-pressuredetermination;

d. determination of electrical characteristics and pressure integrity of solenoid valve(s);

e. determination of pressure integrity and stroke capability of air actuator;

f. determination of operation and electrical characteristics of position indicators;

g. determination of operation and electrical characteristics of bellows arm switch;

h. determination of actuating pressure of auxiliary actuating device sensing element, where applicable, and electrical continuity;

i. determination of compliance with the Owner's seat tightness criteria.

4.

Reason for Request

Pursuant to 10 CFR 50.55a, "Codes and Standards," paragraph (z)(1), reliefis requested from the requirements of ASME OM Code Appendix I, sections I-1320 and I-3310. The proposed alternative would provide an acceptable level of quality and safety. Section ISTC-5240, "Safety and Relief Valves," directs that safety and relief valves meet the inservice testing requirements set forth in Appendix I of the ASME OM Code. Although Appendix I, Section I-1320(a)(2), now has a 6-yr test interval option, the Code is not clear on how a combination of entire valves for a portion of the group and pilot assemblies only for a portion of the group may be utilized to fully meet all the requirements of code. Therefore, this request is being submitted to document the CNS approach for these valves. CNS has eight Main Steam (MS) safety relief valves (SRV). The approach for the past several years has been to remove elther 2 or 3 of the entire valves (i.e. main body and pilot assanbly) every refueling outage and send them off for as found testing, refurbishment, rebuilding, and re-certification in preparation for the next time they are re-installed into the plant. Those2 or 3 entire valves have been replaced with refurbished valves that were recertified just prior to the outage. The schedule is planned so that all eight entire valves get sent off, as found tested, refi.ubished, and re-certified within a three-cycle frequency. In addition, CNS has replaced the remainder of the pilot assemblies (5 or 6 per outage) and sent them off for testing, refurbishment, and re-certification in preparation for the next time they are re-installed into the plant. These 5 or 6 additional pilot assemblies are replaced with refurbished and recertified pilot assemblies that were recertified just prior to the outage. Therefore, the pilot assemblies for the full complement of8 valves have been set pressure tested every outage for several years.

NLS20250l 1 Page 50 of91 Relief Request RV-02 Main Steam Safety Relief Valve Testing (Continued) CNS plans to continue this approach into the upcoming COR interval. Since refueling outage27 (Fall2012), CNS has been operating under a24-monthcycle. Therefore, the refurbishment of the entire valves is aligned with a six-year frequency, which is consistent with I-1320(a)(2). However, all eight of the pilot assemblies are being removed, tested and replaced with refurbished/recertified spare pilot assemblies every refueling outage, which means a full complement of the set pressure portion of the valves are being tested every refueling outage. Therefore, although this approach is vay conservative, documenting acceptability of this approach is being pursued per this reliefrequest. Additionally, since 5-6 pilot assemblies, alone, are being replaced every outage (versus the entire valve), documenting acceptability of how portions of Appendix I-3310 are being satisfied is also being pursued per this reliefrequest.

5.

Proposed Alternative and Basis for Use These eight SRVs are considered Class 1 main steam pressure relief valves with auxiliary actuating devices. They are located on the main steam lines. In addition to their automatic function of opening to prevent over pressurization of the reactor vessel, six of these valves are associated with the Automatic Depressurization System and two are associated with the Low Low Set logic. The valves are two-stage Target Rock valves, each equipped with a main body, a pilot assembly for set pressure control, a solenoid valve, and an air operator assembly. CNS proposes to follow the I-1320(a)(2) requirements for Maintenance on these eight valves. Therefore, on a three cycle (-6 year) frequency, CNS proposes to remove the entire valve unit (i.e. main body and pilot assembly) for each one of these valves and ship it off for as found testing, refi.rbishment, and re-certification. CNS will replace these entire valve units with spare refurbished and re-certified entire valve units. As mentioned earlier, each valve is equipped with a pilot valve assembly that controls the set pressure. The remainder of the pilot valve assemblies (5 or 6 per refueling outage) will be removed from the main body and sent off site for examination, as found testing, refurbishment, and re-qualification testing (set point, main body seat tightness, and pilot stage seat tightness). The test facility has a main body slave for this purpose. The removed pilot valve assemblies are replaced with previously refurbished and re-qualified pilot valve assemblies. By testing all of the pilot valve assemblies every outage, the potential need to expand to test additional valves due to set pressure failures is alleviated and the future valve reliability is improved. Test results are being monitored by serial numbers. Any as found set pressure failure will be addressed via the CNS Corrective Action Program. ASME OM Code Interpretation, 98-8, clarifies that a pilot operated relief valve with an auxiliary actuating device is not required to be tested as a unit. Furthermore, it clarifies that set pressure determination on the pilot operator may be performed after the pilot operator is removed from the valve body.

NLS202501 1 Page 51 of91 Relief Request RV-02 Main Steam Safety Relief Valve Testing (Continued) Appendix I, I-3310(a) visual examination is completed at the test facility for those main bodies and pilot assemblies being sent there for examination, testing and refurbishment. With the removal of the pilot assemblies from the main bodies at the plant, the accessible portions of the main bodies will be examined in place without further disassembly as permitted by I-1310(c). Appendix I, I-3310(b) seat tightness, and I-3310(c) set pressure, is satisfied through as found seat leakage and set pressure testing at the offsite test facility for those main valves and pilot valve assemblies being sent there for inspection, testing and refurbishment. Paragraph I-3310(i) is satisfied through as left seat leakage testing at the facility. Seat leakage of installed main valves is continuously monitored and also satisfies I-3310(D. Pressure switches in the SRV discharge lines annunciate in the control room and indicate when the main valve seat is open. In addition, there are temperature elements on the valve discharge lines which provide leakage indication. During startup, the main valve and Auxiliary Actuation Devices are verified to function properly by being fulI stroke exercised open and closed. Successfully exercising these valves open and closed verifies the electrical characteristics and pressure integrity ofthe solenoid valve and air actuator (satisfying Appendix I, paragraphs (d) and (e)). During this exercise, Appendix I, paragraph I-3310(f), is also satisfied through the use ofthe valve indicating lights, discharge pressure switches, and temperature elements. Finally, Appendix I, paragraphs I-3310(g) and I-3310(h), are not applicable to the CNS MS safety relief valves. This proposed alternative is consenrative in nature and will continue to provide an acceptable level of quality and safety pursuant to 10 CFR 50.55a(z)(1).

6.

Duration of Proposed Alternative This proposed alternative will be utilized for the entire Code of Record interval that uses the 2022 Edition of the ASME oM code, beginning on March 1,2026, and ending on February 28th, 20s0.

7.

Precedents This relief request was approved for the fifth ten-year interval at CNS as RV-03 (CAC NOS. MF5911, MF5913, MF5g14, MF5g15, MF5g16, MF5g17, MF5g1g, MF5g1g, MF5g20, :l;lFsgzl, MF5922, MF5923, MF5924, MF5925, and MF5926, February 12,2016). A version of this relief request was previously approved for the fourth ten-year interval at CNS as Relief Request RV-04 (TAC Nos. MC8 837, MC8975, MC897 6, MC897 7, MC8978, MC897 9, MC8980, MC898 1, MC8989, MC8990, MC8991, and MC8992, Jlur;re 14, 2006).

NLS20250l I Page 52 of9l Relief Request RV-03 Control Rod Drive (CRD) Technical Specification Testing Proposed Alternative in Accordance with 10 CFR 50.55a(z)(1) Alternative Provides Acceptable Level of Quality and Safety

1.

ASME Code Comnonent(s) Affected Valve CRD-SOV-SO120* CRD-SOV-SO121* CRD-SOV-SOI22* Cm-sov-sol23* CRD-AOV.CV126* CRD-AOV-CVI27* CRD-CV-I I4CV* CRD-CV-138CV* Class Category System CRD CRD CRD CRD CRD CRD CRD CRD 2 2 2 2 2 2 2 2 B B B B B B C C 3 SOV:Solenoid Operated Valve AOV:Air Operated Valve CV:Check Valve

• Typical of 137 Hydraulic Control Units (HCLI)

Applicable Code Edition and Addenda

ASME OM Code 2022Edition

Applicable Code Requirement

ASME OM Code ISTC-3500 Valve Testing Requirements - Active and passive valves in the categories defined in ISTC-I300 shall be tested in accordance with the paragraphs specified in Table ISTC-3500-1 and the applicable requirements of ISTC-5100 and ISTC-5200. ISTC-3510 Exercising Test Frequency - Active Category A, Category B, and Category C check valves shall be exercised nominally every three (3) months, except as provided by ISTC-3520, ISTC-3540, ISTC-3550, ISTC-3570, ISTC-5227, and ISTC-5222, andDivision 1, Mandatory Appendix III. ISTC-3560 Fail-Safe Valves - Valves with fail-safe actuators shall be tested by observing the operation of the actuator upon loss of valve actuating power in accordance with the exercising frequency of ISTC-3510. AOV fail-safe test frequency shall meet the requirements of Dividionl, Mandatory Appendix IV. ISTC-5l13(a) Valve Stroke Testing - Active valves shall have their stroke times measured when exercised in accordance with ISTC-3500.

NLS20250l I Page 53 of91 Relief Request RV-03 Control Rod Drive (CRD) Technical Specification Testing (continued) ISTC-5151(a) Valve Stroke Testing - Active valves shall have their stroke times measured when exercised in accordance with ISTC-3500. ISTC-5221(a) Valve Obturator Movement - The necessary valve obturator movement during exercise testing shall be demonstrated by performing both an open and a close test.

4.

Reason for Request

Pursuant to 10 CFR 50.55a, "Codes and Standards," paragraph (z)(l), relief is requested from the requirements of ASME OM Code ISTC-3500, ISTC-3510, ISTC-3560, ISTC-5131(a), ISTC-5151(a), and ISTC-5221(a). The proposed altemative would provide an acceptable level of quality and safety. This relief is needed to make the COR Interval consistent with NUREG 1482, Revision 3.

5.

Proposed Alternative and Basis for Use Background Information It is typical for Boiling Water Reactors (BWR) to perform the subject CRD testing per their respective plant Technical Specifications. This originated from Generic Letter (GL) 89-04, Position 7. Per section 1.3 of NUREG 1482, Revision 3, specific relief is required to implement the guidance derived from GL 89-04, which is why this testing is being documented under a relief request. The proposed altematives and the basis for use are discussed in further detail below. CRD-CV-I 38CV; CRD-SOV-SO120, SO121. SOI22. SO123: The CRD cooling water header check valve, CRD-CV-l38CV (typical of 137 HCUs), has a safety function to close in the event of a scram to prevent diversion of pressurized HCU accumulator water to the cooling water header. The exhaust water withdrawal/settle (CRD-SOV-SO120), exhaust water insert (CRD-SOV-SO121), drive water withdrawal (CRD-SOV-SOl22), and drive water insert (CRD-SOV-SO123) solenoid valves (typical of 137), have a safety function to close in order to provide a boundary to non-code class piping. Normal control rod motion will veriff that the associated cooling water check valve has moved to its safety function position of closed. Industry experience has shown that rod motion may not occur if this check valve were to fail in the open position. The solenoid valves listed above have a safety function to close in order to provide a class 2 to non-code class boundary isolation. During normal operation, these solenoid valves are used for control rod insertion and withdrawal. They are exercised open and closed during normal operation of the associated CRD. They are not equipped with position indication or control switches. They automatically change position to affect control rod movement. Therefore, control rod exercising in accordance with the CNS Technical Specifications, Surveillance Requirement (SR) 3.1.3.3, will provide an acceptable level of quality and safety for

NLS202501 1 Page 54 of91 Relief Request RV-03 Control Rod Drive (CRD) Technical Specification Testing (continued) these valves. This testing method is consistent with GL 89-04, Position 7, andNUREG 1482, Revision 3, Section 4.4.6. ripn A^ V-CV1t< rrDT\\ Ar\\\\/ -f.\\11.)1 anr{ laPT) (a\\/ 1 1 Arrl.t These valves operate as an integral part of their respective HCU to rapidly insert the control rods in support of a scram. The CRD scram inlet valve, CRD-AOV-CVL26 (typical of 137), opens with a scfttm signal to pressurize the lower side of the Control Rod Drive Mechanism (CRDM) pistons from the accumulator or from the charging water header. The CRD outlet isolation valve, CRD-AOV-CVl27 (typical of 137), opens with scram signal to vent the top of the CRDM piston to the scram discharge header. The CRD scram outlet check valve, CRD-CV-I14CV (typical of 137), opens to allow flow from the top of the CRDM piston to the scram discharge header. Individual stroke time measurements of air-operated valves CRD-AOV-CV126 and CRD-AOV-CV127 are impractical due to their rapid acting operation and they are not equipped with position indication. Therefore, valve stroke times will not be measured. Additionally, the air-operated valves fail-open on a loss of air or power. Normal opening removes power to the pilot solenoid valve, simulating a loss of power. On loss of power, the solenoid vents the air operator and CRD-AOV-CVI26 and CRD-AOV-CVl27 are spring-driven open. Thus, each time a scram signal is given, the valves "experience" a loss of airlpower to verifu each valve's fail-safe open feature. Testing these valves simultaneously would result in a full reactor scram. An excess number of scrams performed routinely could cause thermal and reactivity transients, which could lead to fuel, vessel, CRD, or piping damage. The CRDs cannot be tested during cold shutdown because the control rods are inserted and must remain inserted. Therefore, control rod scram time testing in accordance with the CNS Technical Specifications, SR 3.1.4.1, SR 3.1.4.2, SR 3.1.4.3, and SR 3.1.4.4, will provide an acceptable level of quality and safety for these valves. This testing method for these valves is consistent with GL 89-04, Position 7, and NTIREG 1482, Revision 3, Section 4.4.6.

6.

Duration of Proposed Alternative This proposed altemative will be utilized for the entire Code of Record interval that uses the 2022 Edition of the ASME OM Code, beginning on March 1,2026, and ending on February 28th, 2050.

7.

Precedents This relief request was approved for the fifth ten-year interval at CNS as RV-03 (CAC NOS. MF5911, MF5913, MF5g14, MF5g15, MF5g16, MF5g17, MF5g1g, MF5g1g, MF5g20, MF5g21, MF5922,MF5923,MF5924, MF5925, and MF5926, February 12,2016). This relief request was previously approved for the fourth ten-year interval at CNS as relief request RV-06 (TAC No. MEl521, Aprit26,2010). A similar alternative was approved at Perry-l for relief request VR-l, revision 1 (TAC No. ME7380, February 22,2012).

NLS202501 1 Page 55 of91 Relief Request RV-04 Performance-Based Scheduling of Pressure Isolation Valve Leakage Tests Proposed Alternative in Accordance with 10 CFR 50.55a(z)(l) Alternative Provides Acceptable Level of Quality and Safety

1.

ASME Code Component(s) Affected Valve RHR-MOV-M025A RHR-MOV-MO25B RHR-MOV-MO274A RHR-MOV-MO274B RHR-CV-26CV RHR-CV-27CV RHR.MOV-MOI7 RHR-MOV.MOI8 CS-MOV-MOIZA CS-MOV-MO128 CS-CV-18CV CS-CV-I9CV Class Category System RHR RHR RHR RHR RHR RHR RHR RHR CS CS CS CS I 1 1 I I I 1 1 I 1 I 1 A A A A NC NC A A A A NC NC 2. 3. MOV:Motor Operated Valve

Applicable Code Edition and Addenda

ASME OM Code 2022Edition

Applicable Code Requirement

ISTC-3630 - Leakage Rate for Other Than Containment Isolation Valves. ISTC-3630(a) - Frequancy. Tests shall be conducted at least once every two years

Reason for Request

Pursuant to 10 CFR 50.55a, "Codes and standards," paragraph (z)(1), relief is requested from the requirement of ASME OM Code ISTC-3630(a). ISTC-3630(a) requires that leakage rate testing (water) for pressure isolation valves (PIV) be performed at least once every two years. Data from RE25 and RE26 was used to identify that PIV testing alone each refueling outage incurs a total dose of at least 600 mRem. The reason for this relief request is to reduce outage dose and to continue to implement a performance-based approach for the PIV testing that has worked well since implemented in the 2072-time frame. The basis of this relief request is that the proposed alternative would provide an acceptable level of quality and safety. 4.

NLS202501 I Page 56 of91 Relief Request RV-04 Performance-Based Scheduling of Pressure Isolation Valve Leakage Tests (continued)

5.

Proposed Alternative and Basis for Use The RHR and CS systems at CNS contain valves that function as PIVs. PIVs are defined as two normally closed valves in series at the reactor coolant system boundary that isolate the reactor coolant system from an attached low pressure system. These affected valves, listed in Section 1, are located on the 'A' and 'B' CS and RHR injection lines and the RHR shutdown cooling line. PIVs are not specifically included in the scope for performance-based testing as provided for in 10 CFR 50 Appendix J, Option B. The concept behind the Option B altemative for containment isolation valves is that licensees should be allowed to adopt cost effective methods for complying with regulatory requirements. Additionally, NEI 94-01, Revision 0, "Industry Guideline for Implementing Performance-Based Option of 10 CFR Part 50, Appendix J," describes the risk-informed basis for the extended test intervals under Option B. That justification shows that for valves which have demonstrated good performance by passing their leak rate tests (air) for two consecutive cycles, further failures appear to be governed by the random failure rate of the component. NEI 94-01 also presents the results of a comprehensive risk analysis, including the statement that "the risk impact associated with increasing fleakrate] test intervals is negligible (less than 0.1 percent of total risk)." The valves identified in this relief request are in water applications. The PIV testing is performed with water pressurized to normal plant operating pressures. This relief request is intended to provide for a performance-based scheduling of PIV tests at CNS. As stated in the previous section, the reason for requesting this relief is dose reduction. Data reviewed from RE25 and RE26 identified that PIV testing alone incurred a total dose of approximately 600 Inrem in RE26, which benefited from the chemical decontamination that was performed, and approximately 1600 mrem in RE25. Therefore, assuming the PIVs remain classified as good performers, extended test intervals of three refueling outages would provide a savings of at least 1200 mrem over a three-cycle period. NTIREG 0933, "Resolution of Generic Safety Issues," Issue 105, discusses the need for PIV leak rate testing based primarily on three pre-I980 historical failures of applicable valves industry-wide. These failures involved human errors in either operations or maintenance. None of these failures involved inservice equipment degradation. The performance of PIV leak rate testing provides assurance of acceptable seat leakage with the valve in a closed condition. Typical PIV testing does not identify functional problems which may inhibit the valves ability to re-position from open to closed. For check valves, such functional testing is accomplished per ASME OM Code ISTC-3500. Active motor-operated valves are routinely full stroke exercised per ISTC-5120 (references Mandatory Appendix III) to ensure their functional capabilities. The periodic functional testing of the PIVs is adequate to identifu abnormal conditions that might affect closure capability. Performance of the separate 24-monthPlV leak rate testing does not contribute any additional assurance of functional capability; it only determines the seat tightness of the closed valves.

NLS2025011 Page 57 of 91 Relief Request RV-04 Performance-Based Scheduling of Pressure Isolation Valve Leakage Tests ( continued) CNS proposes to perform PIV testing at intervals ranging from every refueling outage to every third refueling outage. The specific interval for each valve would be a function of its performance and would be established in a manner consistent with the containment isolation valve (CIV) process under 10 CFR 50 Appendix J, Option B. Five of the 12 valves listed in Section 1 (RHR-MOV-MO25A, RHR-MOV-MO25B, CS-MOV-MO12A, CS-MOV-MO12B, RHR-MOV-MOl 7) are also classified as CIVs and are leak rate tested with air at intervals determined by 10 CFR 50 Appendix J, Option B. Appendix J and inservice leak testing program guidance will be established such that if any of those five valves fail either their as found CIV test (programmatic operability limit) or their PIV test (operability limit), the test interval for both tests -will be reduced to every refueling outage until they can be re-classified as good performers per Appendix J, Option B requirements. The test intervals for the seven remaining valves with a PIV-only function will be determined in the same manner as is done under Option B. That is, the test interval may be extended to every three refueling outages (not to exceed a nominal six-year period) upon completion of two consecutive, periodic PIV tests with results within prescribed acceptance criteria. Any valid test failure will require a return to the initial interval ( every refueling outage) until good performance can again be established. The primary basis for this relief request is the historically good performance of the PIV s. There have been no valid PIV seat leakage failures since PIV testing began at CNS in 1995 through the present. Leakages recorded have been a very small percentage of the overall allowed leakage. The test results for the PIV s listed in Section 1 have been exceptional. For example, a plot of the RHR-MOV-MOl 7 test results is shown below: RHR-r.tOV-fJ017 P1V est Data 5.00 .50 - 4.00 3.50-3.00- ~ 2.50-

a.

0 2.00 - 1.50-1.00 ~ 0.50-0:00 11/0911995 03/29/2001 0811812006 01J07/2012 0512712017 10/1612022 Date

NLS20250l 1 Page 58 of91 Relief Request RV-04 Performance-Based Scheduling of Pressure Isolation Valve Leakage Tests (continued) This graph is typical of the affected PIVs listed in Section 1; however, there have been cases where the CIV air testing has indicated a failure with components identified in this relief request. There is a general industry-wide consensus that CIV air testing is a more challenging and accurate measurement of seat condition, and more likely to identitr any seat condition degradation. PIV testing has also been utilized at CNS as a post-maintenance test following packing replacements on the CS and RHR injection check valves to ensure the packing is adjusted adequately at normal system pressure. Therefore, PIV testing will continue to be utilized as post-maintenance testing, as necessary. On June 8,2012, the NRC staff reviewed and endorsed NEI 94-01, Revision 3 (see the safety evaluation at Accession No. ML121030286), which allows for up to a 75-month frequency for "Type C tests." Per the NRC safety evaluation report (SER) for the fourth interval IST Program (TAC No. M87021, dated August28,2072), to obtain a frequency extension beyond 60 months (up to 75 months), licensees should provide additional information, such as maintenance history, acceptance tests criteria, condition monitoring programs, etc., to justify the acceptability of the extension. In order to further justiS the proposed maximum frequency of 3 cycles (72 months) with a standard grace period of 6 months, additional information is being provided. Table 1 of this relief request contains the maintenance history, Local Leak Rate Test (LLRT), and Pressure Isolation Valve (PIV) test history for all 12 of these pressure isolation valves for the past 20 years (since 01/01/2005). The table includes the as found and as left LLRT and PIV test results with the associated operability limits. Note that corrective and preventative maintenance has been performed over the past 20 years (and beyond) to maintain the acceptable performance of the components. For instance, the MOV Program requires regular inspections and diagnostic tests (now covered by Appendix III of the ASME OM Code) of the motor operators to ensure that they continue to be relied upon throughout the life of the plant and the check valves have preventative maintenance plans, as necessary, to ensure the packing material is properly maintained. Note that not all of the maintenance performed impacts the seating ability of the components or the test boundary of the associated LLRT/PIV tests, so pre-or post-LLRT/PIV testing may not have been required to be performed. Exercise testing, stroke time testing, and position indication testing was not listed in Table 1. As can be observed from Table 1, the As Found LLRT test results have been excellent with no failures associated with these valves over the past 20 years and a significant amount of margin has been maintained to the programmatic component operability limit. Even more so, avery large margin exists between the PIV test results and the operability limit for each PIV test. With a limit of 5 gpm, the highest recorded PIV leakage in the last 30 years was 0.52 gpm, which is only 10.40% of the allowed leakage. Historically, since 1995, all of the PIV valves have maintained this much or more of a margin to the 5 gpm acceptance criteria as shown in the following table.

NLS202501 1 Page 59 of91 Relief Request RV-04 Performance-Based Scheduling of Pressure Isolation Valve Leakage Tests (continued) The NRC SER for NEI TR 94-01, Revision 3, resulted in a condition that the licensee report the margin between the Type B and Type C leakage rate summation and its regulatory limit and maintain an acceptable margin to the regulatory limit. A second condition requires the licensee to include considerable extra margin in order to extend the LLRT intervals beyond 5 years to a75-month interval. In comparison, for these PIV tests, CNS will establish an administrative limit of <1 gpm for each of the PIV tests in order to maintain each test on an extended frequency. This administrative limit is only 20%o of the allowed leakage and will provide considerable extra margin to the limit of 5 gpm when looking at the historical test results. NUREG/CR-5928, "ISLOCA Research Program Final Report," evaluated the likelihood and potential severity of inter-system loss-of-coolant accident $SLOCA) events in BWR and pressurized water reactors. The BWR design used as a reference for this analysis was a BWR/4 with a Mark I containment. CNS was listed in Section 4.1 of NUREG/CR-5928 as one of the applicable plants. The applicable BWR systems were individually analyzed and in each case, this report concluded that the system was ".. judged to not be a concern with respect to ISLOCA risk." Section 4.3 concluded the BWR portion of the analysis by saying "ISLOCA is not a risk concern for the BWR plant examined here." Summary of bases / rationale for this relief request o Performance-based PIV testing would yield a dose reduction of up to 1200 tnrem over a three-cycle period. o Performance of separate functional testing of PIVs per ASME Code. o Excellent historical performance results from PIV testing for the applicable valves. o Low likelihood of valve mispositioning during power operations (procedures, interlocks) o Air testing versus water testing - degrading seat conditions are identified much sooner with air testing. Test # Components Maximum PIV leakage recorded since 1995 (mm) Percent of allowed leakage Percent of margin to 5 sDm limit 1 RHR-MOV-MO25A 0.42 8.40% 9r.60% 2 RHR-MOV.MO25B 0.272 5.44% 94.56% 3 RHR-CV-26CV / RHR-MOV-MO274A 0.46 9.20% 90.80% 4 RHR-CV-27CV / RHR-MOV-MO274B 0.326 6.52% 93.48% 5 RHR-MOV-MOI7 0.163 3.26% 96.75% 6 RHR-MOV.MOI8 0.s2 r0.40% 89.60% 7 CS-MOV-MOI2A 0.435 8.70% 91.30o/o 8 CS.MOV-MO12B 0.082 1.64% 98.36% 9 CS-CV-18CV 0.3264 6.53% 93.47% 10 CS-CV-19CV 0.082 t.64% 98.36%

NLS20250I I Page 60 of91 Relief Request RV-04 Performance-Based Scheduling of Pressure Isolation Valve Leakage Tests (continued) Relief valves in the low pressure piping - these relief valves may not provide ISLOCA mitigation for inadvertent PIV mispositioning (gross leakage), but their relief capacity can easily accommodate conservative PIV seat leakage rates. Alarms that identify high pressure to low pressure leakage - Operators are highly trained to recognize symptoms of a present or incipient ISLOCA and to take appropriate actions. The intent of this relief request is simply to allow for a performance-based approach to the scheduling of PIV leakage testing. It has been shown that ISLOCA represents a small risk impact to BWRs such as CNS. CNS PIVs have an excellent performance history in terms of seat leakage testing. CNS has demonstrated that this same performance-based approach has worked well since being implemented inthe 2012-time frame under previously approved relief requests. The risks associated with extending the leakage test interval to a maximum of three refueling outages (nominal 24 months) are extremely low. The performance-based interval shall not exceedT2 months. Standard scheduling practice may extend the program interval by 25Yo, not to exceed six months. This relief will provide significant reductions in radiation dose.

6.

Duration of Proposed Alternative This proposed altemative will be utilized for the entire Code of Record interval that uses the 2022 Edition of the ASME OM Code, beginning on March 1,2026, and ending on February 28th, 20s0.

7.

Precedents This relief request was approved for the fifth ten-year interval at CNS as RV-05 (CAC NOS. MF5911, MF5913, MF5gl4, MF5gi5, MF5g16, MF5g17, MF5g1g, MF5g1g, MF5g20, MF5g21, MF5922,MF5923,MF5924, MF5925, and MF5926, February 12,2016). A version of this relief request was previously approved for the fourth ten-year interval at CNS as relief request RV-07 (TAC No ME702l, datedS-28-2012). Fermi 2 received a Safety Evaluation by the NRC, dated September 28,2010, on a similar relief request for the performance-based testing of PIVs (TAC No. ME2558,ME2557, and ME2556). a a

NLS202501 1 Page 61 of91 AF: As Found AL: As Left CM : Corrective Maintenance PM : Preventive Maintenance Relief Request RV-04: Table 1: Maintenance and PIV/LLRT Test History Since 0110112005 Comments LLRT and PIV test due. No impact on LLRT or PIV testing. No impact on LLRT or PIV te stine. No impact on LLRT or PIV testins. Major maintenance resets LLRT Freq. to every refueling outaqe. No impact on LLRT or PIV testins. No impact on LLRT or PIV testing. 1st periodic test for LLRT (and PIV) test. AL Tests NiA N/A N/A N/A LLRT (Final AL): 7.95scfh(<30 scfh)) PIV: 0.08 gpm (AL) N/A N/A N/A AF Tests LLRT: 2.02 scfh (< 30 scftr) PIV: 0.299 gpm (< 5 som) N/A N/A N/A LLRT: 0.83 scfh (< 30 scftr) N/A N/A LLRT: 1.25 scfh (< 50 scftr) PIV: 0.109 gpm (< 5 spm) Work Order Description N/A Remove insulation and validate leak; tightened cap screws on pressure seal: slowed leakase. Efforts were made to stop bonnet seal leak. Clean & Lubricate Stem Repaired pressure seal leak, refurbed motor operator, disassembled and examined valve, and diagnostically tested. Perform Motor Pinion Inspection Examine MO-Mech Examine MO-Elect N/A Work Order N/A cM 4464719 cM4465302 PM 4390882 clsl4464912 cM 4534360 PM 4542913 PM 4498618 PM 4498668 N/A Outage RE22 Online Online Online RE23 Online Online RE24 -Date Spring/2005 101021200s 02/10/2006 05/3012006 FalV2006 04/03/2007 t0/04/2007 Spring/2008 Comoonent(s) RHR-MOV-M025A (Test #l)

NLS20250l I Page 62 of9l AF: As Found AL: As Left CM : Corrective Maintenance PM : Preventive Maintenance Comments No impact on LLRT or PIV testing. No impact to LLRT orPIV testing. 2nd periodic test for LLRT (and PIV) test. 3rd (extra) periodic test for LLRT (and PIV) test. No impact on LLRT or PIV testins. No tests due to Option B / approved PIV reliefreouest. No PIV test due to approved PIV reliefrequest. No impact on LLRT or PIV testins. AL Tests N/A PIV: 0.109 gpm (< 5 gpm) N/A N/A N/A N/A N/A LLRT: l.5l scftr (< 50 scfh) PIV: 0.027 som (< 5 eom) AF Tests N/A LLRT: 1.75 scfh (< 50 scfh) LLRT: 2.1 scfh (< 50 scfh) PIV: 0.136 gpm (< 5 spm) N/A N/A LLRT: 3.82 scfh (< 50 scftr) N/A LLRT: 3.42 scfh (< 50 scfh) Work Order Description Clean & Lubricate Stem Examine MO-Mech Examine MO-Elec MOV Program Diagnostic test/motor replacement. No AL LLRT required due to minimal seat thrust change. N/A Clean and Lubricate Stem Examine MO-Mech Examine MO-Elec N/A N/A Clean and Lubricate Stem Examine MO-Mech Examine MO-Elec Perform Diagnostic Testing PIV Test Work Order PM 462s205 PM462s262 PM 4625267 cM 4641890 N/A PM 4802964 PM 4803040 PM 48030s2 N/A N/A PM 5003116 PM 5003160 PM 5003163 PM 5101221 SURV s060024 Outaee Online RE25 RE26 Online RE27 RE28 Online RE29 -Date 03/30/2009 FalU2009 Spring/201I 06/0st2012 Fall/2012 FaIU20l4 ApriV20l5 FalV2}l6 ReIief RV-04: Table 1: Maintenance and PIV/LLRT Test Since 0110112005 Component(s)

NLS202501 1 Page 63 of91 AF: As Found AL: As Left CM : Corrective Maintenance PM : Preventive Maintenance Comments No impact on LLRT or PIV testins. PIV test not required. No impact on LLRT or PIV testing. Periodic PIV test. No impact on LLRT or PIV testins. Boundary valve leakage on as found LLRT test. PIV Test not required. MOV periodic test. No impact on LLRT or PIV testinq. No impact on LLRT or PIV testing. AL Tests N/A LLRT: 1.9 scfh (< 50 scftr) N/A N/A N/A LLRT: 3.48 scfh (< 50 scfh) LLRT: 23.8 scfh (< 30 scfh) PIV: 0.0544 gpm (< 5 gpm) N/A N/A AF Tests N/A LLRT: 5.7 scfh (< 50 scftr) N/A PIV: 0.42 spm (< 5 epm) N/A LLRT: 27.82 scftr (< 50 scfh) LLRT: 24 scfh (< 30 scfh) N/A N/A Work Order Description Examine MO-Elec Examine MO-Mech Clean and Lube Stem Adjust Packing LLRT Examine MO (Mech/Elect) PIV Test Examine RHR-MO-MO25A (Clear/Lube) Perform Diagnostic Testing LLRT Votes diagnostic test Clean and Lubricate Stem Examine Torque Switch Work Order PM 5t67376 PM 5167373 PM 5167360 cM5287222 SURV 5282491 PM 5413009 SURV s382642 PM 5488019 PM 5483385 SURV s47s663 c}/44335229 PM 4381354 cM 4531030 Outase Online RE3I Online RE32 Online RE33 RE22 Online Online -Date ApriV2018 Sept./2018 Fall/2020 Apil/2022 FalU2022 ApriU2024 FalU2024 Spring/2005 04/tt/200s t0/17/2006 Relief uest RV-04: Table 1: Maintenance and PMLLRT Test Since 0110112005 Component(s) RHR-MOV-MO258 (Test #2)

NLS202501 I Page 64 of9l AF: As Found AL: As Left CM : Corrective Maintenance PM : Preventive Maintenance Relief Request RV-04: Table 1: Maintenance and PMLLRT Test History Since 0110112005 Comments No impact on LLRT or PIV testine. No impact on LLRT or PIV testing. Monitoring LLRT; assume I st periodic test for PIV. No impact on LLRT or PIV testing. No impact on LLRT or PIV testing. Monitoring LLRT;2nd periodic test for PIV. No impact on LLRT or PIV testing. Monitoring LLRT;3rd periodic test for PIV. No impact on LLRT or PIV testine. AL Tests N/A PIV: 0 gpm (< 5 gpm) N/A N/A N/A N/A N/A AF Tests N/A LLRT: 17.5 scfh (< 50 sc{h) N/A LLRT: 32.14 scftr (< 50 scfh) PIV: 0.0544 gpm (< 5 cpm) N/A LLRT: 12.74 scfh (< 50 scfh) PIV: 0.054 eom (< 5sDm) N/A Work Order Description Replace Motor Pinion Gear Packing Leak;No AL LLRT required due to minimal packing/seat load change. Examine MO-Elec Examine MO Repack valve Adjust Packing/Viper Test Refurbed AO; No AL LLRT/PIV required due to minimal packing/seat load change. Clean and Lubricate Stem N/A Examine MO-Elec Examine MO-Mech Work Order cM 4531090 CM 4537229 PM 4485530 PM 4498698 cM4632406 cM 4631 163 cM 4531210 PM 4600595 N/A Pl[l4664227 PM 4664250 Outage Online RE23 Online RE24 N/A RE25 Online -Date t0/t8/2006 FalV2006 04/t812007 Spring/2008 t0/t4/2008 FalV2009 0'7/t312010 Component(s)

NLS202501 1 Attaclwrent2 Page 65 of91 AF: As Found AL: As Left CM : Corrective Maintenance PM : Preventive Maintenance Comments Monitoring LLRT (lst periodic test); 4th periodic test for PIV. No impact on LLRT or PIV testins. No impact on LLRT or PIV testing. Monitoring LLRT (2nd periodic test); No PIV test due to approved PIV relief request. No impact on LLRT or PIV testine. No impact on LLRT or PIV testins. No tests due to Option B / approved PIV reliefrequest. No impact on LLRT or PIV testins. AL Tests N/A N/A N/A N/A N/A N/A N/A AF Tests LLRT: 23.16 scftr (< 50 scftr) PIV: 0.136 gpm (< 5 spm) N/A LLRT: 0.17 scfh (< 50 scfh) N/A N/A N/A N/A Work Order Descrintion N/A Clean and Lubricate Stem Viper diagnostic test; No AL LLRT/PIV required due to minimal seat load change. Examine MO-Mech Examine MO-Elec Reterminate Motor Wiring N/A Clean and Lubricate stem Work Order N/A PM 4749837 cM4842207 PM 4864090 PM 4864089 cM 4996016 N/A PM 4953672 Outase RE26 Online P.E27 Online Online RE28 Online -Date Spring/2011 07119/2011 FalV20l2 0llt4l20t3 0t/r6120t4 Fall/2014 0Ut2l20ts Relief RV-04: Table 1: Maintenance and PIV/LLRT Test Since 0110112005 Component(s)

NLS202501 1 Page 66 of91 AF: As Found AL: As Left CM : Corrective Maintenance PM : Preventive Maintenance Comments No impact on LLRT or PIV testinq. Periodic LLRT. Periodic PIV test. No impact on LLRT or PIV testing. AL tests not required No impact on LLRT or PIV testing. No impact on LLRT or PIV testins. Periodic LLRT and PIV tests. No impact on LLRT or PIV testins. AL tests not required. AL Tests N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A AF Tests N/A LLRT: 22.45 scfh (< 50 scftr) PIV: 0.0 epm (< 5 epm) N/A LLRT: 9.96 scfh (< 50 scfh) N/A N/A LLRT: 0.21 scfh (< 50 scfh) PIV: 0.0544 gpm (< 5 gpm) N/A LLRT: 1.851 scfh (< 50 scftr) Work Order Description Examine MO-Mech Examine MO-Elect LLRT PIV Test Clean and Lube Stem Perform Diagnostic Testing Examine MO-Mech Examine MO (Lube Stem) PIV Test LLRT Perform MO Exam (Elec/Mech) Perform Diagnostic Testing Work Order PM s040286 PM 504027s SURV 5060035 SURV 5059825 PM 5164150 PM 5173290 PM 5209583 PM 5335248 SURV 5210953 SURV 5382634 PM 5437893 PM 5547956 Outase Online RE29 RE29 Online RE3O Online Online RE33 Online RE33 -Date Jan.l20l6 FalU20l6 FalV20l6 Jan./2018 FalV2Ol8 Jan./2019 Jan./2021 FalV2022 Jan.l2023 FalU2024 Relief RV-04: Table 1: Maintenance and PIV/LLRT Test Since 0l/0112005 Component(s)

NLS202501 1 Page67 of9l AF: As Found AL: As Left CM : Corrective Maintenance PM : Preventive Maintenance Comments No impact on LLRT or PIV testing. Routine PM Assume lst periodic test for LLRT (and PIV) test. No impact on LLRT or PIV testing. 2nd periodic test for LLRT (and PIV) test. No impact on PIV test. LLRT no longer required due to closed loop analysis. 3rd periodic test for PIV test. AL Tests N/A LLRT: 4.7 scfh (< 35 scfh) PIV: 0.041 gpm (< 5 gpm) N/A N/A PIV: 0.082 gpm (< 5 gpm) AF Tests LLRT: 7.5 scfh (< 35 scftr) PIV: 0.1224 gpm (< 5 spm) LLRT: 0.75 scfh (< 35 scfh) LLRT: 4.27 scfh (< 35 scft) PIV: 0.054 gpm (< 5 epm) LLRT: 8.31 scftr (< 35 scfh) PIV: 0.082 gpm (< 5 cpm) N/A Work Order Descriotion Examine Motor Operator Evaluate Packing - Adjust or Repack - Repacked valve Examine Motor Operator N/A Examine MO-Mech Adjust Reed Switches Evaluate Packing - Adjust or Repack - Tightened Packing Work Order RHR-MO-MO274A PM 4363586 RHR-MOV-MO274A: PM 4446728 RHR-MO-MO274A PM 4446878 N/A RHR-MO-MO274A Plsl4645290 RHR-CV-26CV cM4723494 RHR-MOV-MO274A: PM 4744619 Outaee RE22 RE23 RE24 RE25 RE26 -Date Spring/2005 FalV2006 Spring/2008 Fall/2oO9 Spring/201I Relief RV-04: Table 1: Maintenance and PMLLRT Test Since 0ll0l/2005 Component(s) RHR-MOV-MO274A RHR-CV-26CV (Test #3)

NLS202501 l Page 68 of9l AF: As Found AL: As Left CM : Corrective Maintenance PM : Preventive Maintenance Relief Request RV-04: Table 1: Maintenance and PIV/LLRT Test History Since 01/01/2005 Comments No PIV test due to approved PIV relief request. No PIV test due to approved PIV reliefrequest. Periodic PIV test. PIV test not required. Periodic PIV test PIV test not required. AL Tests N/A N/A N/A N/A N/A N/A AF Tests N/A N/A PIV: 0 epm (< 5 epm) N/A PIV: 0.46 spm (< 5 eDm) N/A Work Order Description Repack Valve ; performed exercise test and no external leakage at pressure as PMT; PIV test not required as had no impact to seating ability and located inside Drywell. Adjust Limit Switch Examine MO-Mech N/A PIV test Evaluate Packing Adjust or Repack PIV test Evaluate Packing / Perform Mechanical Inspection Work Order RHR-CV-26CY: PM 4848060 RHR-CV-26CY: cM 4918074 RHR-MO-MO274A: PM 4848151 N/A SURV 5060024 RHR-MOV-MO274A: PM 5172642 SURV 5382642 RHR-MOV-MO274A& RHR-CV-26CY: PM 5482857 Outase FtE2'7 RE28 RE29 RE3O RE32 RE33 -Date FalV20l2 FalV2014 FalV20l6 FalV2Ol8 FalU2022 FalU2024 Component(s)

NLS202501 1 Page 69 of9l AIr: As Found AL: As Left CM : Corrective Maintenance PM : Preventive Maintenance Relief Request RV-04: Table 1: Maintenance and PIV/LLRT Test Historv Since 0l/0112005 Comments AF -AL LLRT. No impact on LLRT or PIV testing. Assume resets LLRT frequency. No impact on LLRT or PIV tests. Assume lst periodic test for LLRT and PIV test. LLRT no longer required due to closed loop analysis. No impact on PIV tesq 2nd periodic PIV test. No PIV test due to approved PIV relief reouest. AL Tests LLRT: 9.4 scftr (< 35 scfh) PIV: 0.136 epm (< 5 epm) PIV: 0.109 gpm (< 5 gpm) LLRT: 28.59 scftt (< 35 scftr) PIV: 0.163 epm (< 5 epm) N/A PIV: 0.326gpm(<5gpm) N/A AF Tests LLRT: 9.6 scfh (< 35 scfh) LLRT: 9.8 scfh (< 35 scftr) LLRT: 14.5 scfh (< 35 scftr) LLRT: 15.7 scftr (< 35 scfh) PIV: 0.2l8gpm(<5 gpm) N/A N/A Work Order Description Refurbish MO Examine MO Evaluate Packing - Adjust or Repack - No packing adjustment required. Examine MO Repacked Valve Examine MO-Mech Evaluate Packing - Adjust or Repack - Tightened packing Examine MO-Mech Work Order RHR-MO-MO2748 cM 4299766 PM 4363585 RHR-MOV-MO2749 PM 4446729 PM 444687s RHR-CV-27CY: PM 4541360 RHR-MO-2748: PM 464s289 RHR-MOV-MO2748: PM 4744620 PM 4848150 Outaee RE22 RE23 RE24 RE25 RE26 RE27 -Date Spring/2005 FalV2006 Spring/2008 FalV2009 Spring/201I Falll20l2 Component(s) RHR-MOV-MO2748 RHR-CV-27CV (Test fl4)

NLS202501 1 Page 70 of91 AF: As Found AL: As Left CM : Corrective Maintenance PM : Preventive Maintenance Comments No PIV test due to approved PIV relief request. Periodic PIV test. PIV test not required. PIV test not required. PIV test not required. Periodic PIV test. No impact on LLRT or PIV testing. Assume lst periodic test for LLRT and PIV. No impact on LLRT or PIV testing. 2nd periodic test for LLRT and PIV. AL Tests N/A N/A N/A N/A N/A N/A AF Tests N/A PIV: 0.l36gpm(<5 spm) N/A N/A N/A PIV: 0epm(<5spm) LLRT: 2.95 scfh (< 30 scfh) PIV: 0.027 gpm (< 5 gpm) LLRT: 1.75 scftr (< 30 scfh) PIV: 0 gpm (< 5 gpm) Work Order Description N/A PIV Test Evaluate Packing, Adjust or Repack Evaluate Packing/Perform Mech Inspection Re-Torque Valve PIV Test Examine MO and Verify Indication Examine MO Clean and Lube Stem Perform Motor Pinion Inspection Work Order N/A SURV 5059825 RHR-MOV-MO2748; PM 5172643 RHR-MOV-MO274B PM 5381 182 RHR-CV-27CV PM 5381 166 SURV s382634 PM 4363507 PI$l4363526 PM 4446718 cM 4535994 Outase RE28 RE29 RE3O RE32 RE32 RE32 RE22 RE23 -Date FalU20l4 FalV20l6 Fall/2018 Fall/2022 FalU2022 FalU2022 Spring/2005 FalU2006 Relief uest RV-04: Table 1: Maintenance and PIV/LLRT Test Since 0ll0ll2009 Component(s) RHR-MOV-MOI7 (Test #5)

NLS202501 1 Page 71 of9l AF: As Found AL: As Left CM : Corrective Maintenance PM : Preventive Maintenance Comments No impact on LLRT or PIV testing. 3rd periodic test for LLRT and PIV. LLRT not required due to Option B; 4th periodic PIV test. LLRT not required due to Option B; 5th periodic PIV test. No PIV test due to approved PIV relief request. No tests due to Option B / PIV relief request. AL LLRT not required. Periodic LLRT and PIV tests. No impact on LLRT or PIV testing. AL Tests PIV: 0 gpm (< 5 gpm) PIV: 0.007 epm (< 5 spm) N/A AF Tests 0.68 scfh (< 30 scfh) LLRT: PIV: 0 gpm (< 5 gpm) PIV: 0.027 gpm(< 5 gpm) LLRT: 5.32 scftr (< 30 scftr) N/A LLRT: 3.67 scfh (< 30 scfh) N/A Work Order Description Replace MO and diagnostic test; AL LLRT not required due to minimal change in seat load. Clean and Lubricate Examine MO - Mech Motor Pinion Inspection Examine MO - Elect Examine MO Examine MO Diagnostic Test Examine MO (Lube Stem) PIV Test LLRT Test Examine MO (Mech/Elec) Work Order cM 4546759 PM 4645142 PM 4744696 cM 4740307 P}/44744691 PM 4848600 PM 4983676 cM 5070638 PM 5057852 SURV 5059869 SURV 5060050 PM 5t73172 Outaee RE24 RE25 RE26 F.E27 RE28 RE29 RE3O -Date Spring/2008 FalU2009 Spring/201I FalU20l2 Fall/2014 FalV2Dl6 FalV2Ol8 Relief RV-04: Table 1: Maintenance and PIV/LLRT Test Since 01/01/2005 Component(s)

NLS202501 1 Page72 of91 AIr: As Found AL: As Left CM : Corrective Maintenance PM : Preventive Maintenance Relief Request RV-04: Table 1: Maintenance and PIV/LLRT Test History Since 0110112005 Comments PIV test not required. Periodic PIV test. PIV test not required. Assume resets LLRT frequency. No impact on LLRT or PIV testing. lst periodic test for LLRT and PIV. AL Tests LLRT: 4.6 scfh (< 30 scfh) N/A LLRT: 6.06 scfh (< 30 scfh) LLRT: 2.06 scfh (< 30 scflr) PIV: 0.0408 spm (< 5 cpm) PIV: 0.109 gpm (< 5 gpm) AF Tests LLRT: 4.9 scfh (< 3"0 scfh) PIV: 0.163 gpm (< 5 gpm) LLRT: 5.05 scfh (< 30 scfh) LLRT: 1.96 scftr (< 30 scfh) LLRT: 2.6 scftr (< 30 scfh) Work Order Description Adjust Packing Examine MO (Clean/Lube) LLRT Test PIV Test Examine MO (Mech/Elec) Diagnostic Test Examine MO (Lube stem) LLRT Test Examine MO and Verify Indication Refurb MO and diagnostic test Examine MO Evaluate Packing Adjust or Repack - (tightened 2 flats); AL LLRT not required due to minimal change in packing and seating forces. Examine Motor Operator Examine MO and Verify Indication Work Order cM 5287223 Pi[((5283392 SURV 5282490 SURV 5382641 PM 5381685 PM 5547958 PM 5483291 SURV 547s662 PM 4363506 cM4212544 PM 4363568 PM 4446',727 PM 4446867 PM 4446860 Outase RE3I RE32 RE33 RE22 RE23 -Date FalU2020 FalU2022 FalU2024 Spring/2005 FalV2006 Component(s) RHR-MOV-MO18 (Test #6)

NLS202501 I Page 73 of91 AF: As Found AL: As Left CM : Corrective Maintenance PM : Preventive Maintenance Comments No impact on LLRT or PIV testing. 2nd periodic test for LLRT and PIV. LLRT no longer required due to closed loop analysis. No impact on PIV test. 3rd periodic PIV test. No impact on PIV test. 4th periodic PIV test. No impact on PIV test. No PIV test due to approved PIV relief request. AL Tests PIV: 0.218 gpm (< 5 gpm) PIV: 0.027 gpm (< 5 gpm) N/A AF Tests LLRT: 0.7 scfh (< 30 scfh) PIV: 0.109 gpm (< 5 gpm) LLRT: N/A LLRT N/A N/A Work Order Description Examine Motor Operator Motor Pinion Gear Inspection Motor Pinion Gear Inspection Evaluate Packing Adjust or Repack - (l flat): Examine MO-Mech Examine MO-Elec Examine MO-Mech Work Order P}'d4549525 cM 4531750 cM 4640553 PM 4744618 PM 4746148 PM 4744690 PM 4848601 Outaee RE24 RE25 RE26 RE27 -Date Spring/2008 Falll2009 Spring/201I Fall/2012 Relief RV-04: Table 1: Maintenance and PMLLRT Test Since 01/01/2005 Component(s)

NLS202501 I Page74 of9l AIr: As Found AL: As Left CM : Corrective Maintenance PM : Preventive Maintenance Comments No PIV test due to approved PIV relief request. Periodic PIV test. PIV test not required. Periodic PIV test. PIV test not required. AL Tests N/A N/A N/A N/A N/A AF Tests N/A PIV: 0.007 gpm (< 5 cpm) N/A PIV; 0.52 gpm (< 5 gpm) N/A Work Order Description Viper Test - no torque switch or packing adjustments required (AF:AL); PIV not required Evaluate Packing Adjust or Repack - Not needed Examine MO (Mech/Elec) Examine MO (Mech). PIV Test Evaluate Packing Adjust or Repack; completed in cM 5137279. Replace Gear Ratio; AL thrust within 0.8% of previous values and no internal work. Examine MO (Elec/Mech) Examine MO (Elec/Mech) PIV Test Diagnostic Testing Work Order cM 4945389 PM 4949440 PM 4950106 PM 5057853 SIJRV 50600s0 PM 5172641 cM s137279 PM 5173173 PM 5381686 SURV s38264t PM s483397 Outage RE28 RE29 RE3O RE32 RE33 -Date FalV20l4 FalV20l6 FalV2Ol8 FalU2022 FalU2024 Relief RV-04: Table 1: Maintenance and PIV/LLRT Test Since 0110112005 Component(s)

NLS202501 1 Page 75 of91 AF: As Found AL: As Left CM : Corrective Maintenance PM : Preventive Maintenance Comments Periodic LLRT and PIV test. Assume lst periodic PIV test. No impact on LLRT or PIV testins. No impact on LLRT or PIV testins. No impact on LLRT or PIV testing. LLRTnot required due to option B. 2nd periodic PIV test. No impact on LLRT or PIV testing. AF-AL LLRT. No impact on LLRT or PIV testing. 3rd periodic PIV test. AL Tests N/A N/A N/A PIV: 0.435 gpm (< 5 epm) N/A LLRT: 1.05 scfh ( < l0 scfh) PIV: 0.19 gpm (< 5 gpm) AF Tests LLRT: 0.004 scftr (< l0 scfh) PIV: 0.299 gpm (< 5 spm) N/A N/A N/A N/A LLRT; 0.86 scftr (< l0 scfh) Work Order Description N/A Clean, Lubric ate, P artial Stroke Adjust Packing (tightened 2 flats); no AL LLRT/PIV required. Motor Pinion Gear Inspection Examine MO - Mech Refurb and test MO Install ETT/QSS Work Order N/A PI[l43872t7 cM 444769t cM 4s3l4s3 PM4s3268s c}l4s47083 cM 456119',1 Outage P.E22 Online Online RE23 Online RE24 -Date Spring/2005 08/02/200s 08102/2006 FalV2006 02/05/2008 Spring/2008 Relief RV-04: Table 1: Maintenance and PMLLRT Test Since 0l/0112005 Component(s) CS-MOV-MOI2A (Test #7)

NLS202501 1 Page76 of9l AIr: As Found AL: As Left CM : Corrective Maintenance PM : Preventive Maintenance Comments No impact on LLRT or PIV testing. LLRT not required due to option B. 4th periodic PIV test. LLRTnot required due to option B. 5th periodic PIV test. No impact on LLRT or PIV testins. No impact on LLRT or PIV testing. 6th periodic PIV test. No impact on LLRT or PIV testing. PIV test not required due to approved relief request. AL Tests N/A N/A N/A N/A AF Tests PIV: 0 gpm (< 5 gpm) PIV: 0 gpm (< 5 gpm) N/A LLRT: 0.1528 scftr (< l0 scfh) PIV: 0 gpm (< 5 epm) LLRT: l.l scfh (< l0 scftr) Work Order Description Adjust close limit switch N/A Clean, Lubricate, and Partial Stroke Examine MO (Mech & Elec); Viper Test; AL LLRT/PIV tests not required due to minimal change in packing and seating forces. Examine MO (Clean/Lube Stem) Work Order cM 4723418 N/A PI0l4749833 PM 4848626 cM49454s4 PM 4950t23 Outaee RE25 RE26 Online R.E27 RE28 -Date FalV2009 Spring/201I 08/10/2011 Fall/2012 FalV20l4 Relief uest RV-04: Table L: Maintenance and PIV/LLRT Test Since 0110112005 Component(s)

NLS202501 I Page77 of9l AIr: As Found AL: As Left CM : Corrective Maintenance PM : Preventive Maintenance Comments No impact on LLRT or PIV testins. PIV test not required. Periodic PIV test. PIV test not required. Periodic LLRT and assume lst periodic PIV test. No impact on LLRT or PIV testing. AL Tests LLRT: 0.458lscftr(<10 scftr) PIV: 0.0136 gpm (< 5 gpm) N/A LLRT: 0.1784 scfh(< l0 scfh) N/A LLRT: 0.042scfh(<10 scfh) N/A N/A AF Tests LLRT: 0.15 scftr (< l0 scfh) N/A LLRT: 0.352 scftr (< l0 scftr) PIV: 0 gpm (< 5 spm) LLRT: 0.042 scftr (< l0 scfh) LLRT: 1.23 scftr (< l0 scfh) PIV: 0 gpm (< 5 gpm) N/A Work Order Description Failed to Fully Close against Pump pressure/flow Periodic PIV Test Examine MO (Mech/Elec) Examine MO (Clean/Lube) Perform Diagnostic Testing. Examine MO (Mech/Elec) PIV Test Replace Compensator and Perform Testing. LLRT N/A Clean/Lube/Partial Stroke Periodic Diagnostic Test; no AL LLRT/PIV Work Order cM s069272 SURV s059027 PM 5057874 PM 5173203 PM 5283415 PM 5283496 SURV s382331 PM 5483396 SURV 547s706 N/A P}l4465037 cM 4334765 Outage RE29 RE3O RE3I RE32 RE33 RE22 Online -Date FalU20l6 Fall/2018 FalU2020 Fall/2022 FalU2024 Spring/2005 08/t4/2006 Relief uest RV-04: Table 1: Maintenance and PMLLRT Test Since 0110112005 Component(s) CS-MOV-MOI28 (Test #8)

NLS202501 I Page 78 of9l AF: As Found AL: As Left CM : Corrective Maintenance PM : Preventive Maintenance Comments No impact on LLRT or PIV testing. LLRT not required due to option B. 2nd periodic PIV test. No impact on LLRT or PIV testing. LLRT not required due to option B. 3rd periodic PIV test. No impact on LLRT or PIV testing. 4th periodic PIV test. No impact on LLRT or PIV testins. No impact on LLRT or PIV testing. LLRT not required due to option B. 4th periodic PIV test. AL Tests N/A N/A N/A N/A N/A AF Tests 0 gpm (< 5 epm) PIV: PIV: 0.082 gpm (< 5 cpm) LLRT: 1.67 scftr (< l0 scftr) PIV: 0 gp- (< 5 gpm) N/A PIV: 0 gpm (< 5 gpm) Work Order Description Motor Pinion Gear Inspection Install ETT/QSS Examine & Clean Operator Clean/Lube/Partial Stroke Examine Motor Operator Work Order cM 4534089 cM 4561 198 PM 4658094 PM4625209 PM 4767601 Outaee RE23 RE24 RE25 Online RE26 -Date Fall/2006 Spring/2008 FalU2009 lUt2/2009 Spring/201I Relief RV-04: Table 1: Maintenance and PIV/LLRT Test Since 0110112005 Component(s)

NLS20250l r Page79 of97 AF: As Found AL: As Left CM : Corrective Maintenance PM : Preventive Maintenance Relief RequestRV-04: Table 1: Maintenance and PMLLRT Test History Since 0110112005 Comments No impact on LLRT orPIV testing. 5th periodic PIV test. No impact on LLRT or PIV testing. No LLRT test performed due to option B and no PIV test performed due to an approved relief request. Periodic

LLRT, Periodic PIV

Test, Periodic LLRT.

AL Tests LLRT: 2.02 scfrt PIV: 0.0136 gpm (< 5 spm) N/A N/A N/A LLRT: 0.423 scfh PIV: 0 eDm (< 5 epm) N/A AF Tests LLRT: 1.82 scfh (< l0 scfh) N/A LLRT: 0.15 scftr (< l0 scfh) PIV: 0.0136 gpm (< 5 cpm) LLRT: 0.423 scftr (< l0 scfh) LLRT: 0.39 scftr (< l0 scftr) Work Order Description Viper Test Examine MO (Mech/Elec) Examine MO (Clean/Lube Stem) LLRT PIV Test Examine MO (Mech/Elec/Lube) Returbish CS-MO-I2B and Test LLRT Examine MO (Mech/Elec) Work Order cM 4840074 PM 4848541 PM 4950054 SLIRV 5060068 SURV 5060012 PM 5057808 cilld4945834 SURV 5282502 PM 5381631 Outaqe RE27 RE28 RE29 RE29 RE3O RE32 -Date FalV20l2 FalV20l4 FalV20l6 FalU2}l6 FalV2Ol8 Falll2022 Component(s)

NLS20250t I Page 80 of91 AF: As Found AL: As Left CM : Corrective Maintenance PM : Preventive Maintenance Comments Periodic PIV test. AL testing not required. LLRT not required due to Option B; periodic PIV test. LLRT not required due to Option B; periodic PIV test. Periodic LLRT and PIV tests. Significant Maint. Resets LLRT/PIV frequencv. LLRT no longer required due to closed loop analysis. First periodic PIV test. AL Tests N/A N/A N/A N/A N/A LLRT (Final AL): 0.79 scfh (< 15 scfh) PIV: 0 gpm (< 5 epm) N/A AF Tests PIV: 0.027 gpm (< 5 spm) LLRT: 0.1631 scftr (< l0 scfh) PIV: 0.3264 gpm (< 5 gpm) PIV: 0.326 gpm (< 5 gpm) LLRT: l.19 scfh (< 15 scftr) PIV: 0.136 gpm (< 5 spm) LLRT: 0.131 scfh (< 15 scftr) PIV: 0 gpm (< 5 gpm) Work Order Description PIV Test Perform Diagnostic Testing N/A N/A N/A Repack Valve Disassemble and Repair following issues during repack N/A Work Order SURV 5382324 PM 5547955 N/A N/A N/A PM 464st2t cM 4724012 N/A Outase RE32 RE33 RE22 RE23 RE24 RE25 RE26 -Date FALL/2022 Fall/2024 Spring/2005 FalV2006 Spring/2008 FalV2009 Spring/2O1I Relief uest RV-04: Table 1: Maintenance and PMLLRT Test Since 0110112005 Component(s) CS-CV-I8CV (Test #9)

NLS202501 I Page 81 of91 AF: As Found AL: As Left CM : Corrective Maintenance PM : Preventive Maintenance Relief Request RV-04: Table 1: Maintenance and PIV/LLRT Test History Since 0110112005 Comments Second periodic PIV test. PIV test not required due to approved relief request. Periodic PIV test. Periodic LLRT and PIV tests. LLRT not required due to Option B; periodic PIV test. Elected to Reset LLRT/PIV frequency. First periodic LLRT and PIV test. AL Tests N/A N/A N/A PIV: 0 gp- (< 5 gpm) N/A N/A LLRT (Final AL): 1.4 scfh PIV Ginal AL): 0.05 epm (< 5 epm) N/A AF Tests PIV: 0 gpm (< 5 gpm) PIV: 0 epm (< 5 spm) N/A LLRT: 0.95 scfh (< l5 scft) PIV: 0 spm (< 5 epm) PIV: 0 gpm (< 5 gpm) LLRT: 0.65 scftr (< 15 scfh) LLRT: 1.37 scfh (< 15 scfh) PIV: 0 epm (< 5 epm) Work Order Description N/A N/A PIV Test Retorque Valve Packing - validated SAT PIV Test N/A N/A AdjusVadd packing Repack valve N/A Work Order N/A N/A SURV 5059027 PM 5381 147 SURV s382331 N/A N/A c][l4631924 PM 4s4t346 N/A Outage RE27 RE28 RE29 RE32 RE22 RE23 RE24 RE25 -Date FalV20l2 FalV20l4 Falll20l6 FalU2022 Spring/2005 FalU2006 Spring/2008 FalV2009 Component(s) CS-CV-I9CV (Test #10)

NLS2025011 Page 82 of9l AF: As Found AL: As Left CM : Corrective Maintenance PM : Preventive Maintenance Comments LLRTno longer required due to closed loop analysis. Second periodic PIV test. No PIV test required due to approved reliefrequest. No PIV test required due to approved reliefrequest. Periodic PIV test. PIV test not required. Initial test was invalid. AL Tests N/A N/A N/A N/A N/A N/A AF Tests PIV: 0 gpm (< 5 gpm) N/A N/A PIV: 0.0136 gpm (< 5 som) N/A PIV: 0.014 gpm (< 5 spm) Work Order Description N/A N/A N/A PIV Test Retorque Valve Packing; no movement SAT Periodic PIV Test Work Order N/A N/A N/A SURV 5060012 PM 5282828 SURV s382324 Outaee RE26 RE27 RE28 RE29 RE3I RE32 -Date Spring/201I FalV20l2 FalV20l4 FalU2016 FalV2020 FalU2022 Relief RV-04: Table 1: Maintenance and PIV/LLRT Test Since 0110112005 Component(s)

NLS202501 1 Page 83 of9l Relief Request RV-05 Supplemental Position Indication Testing of CRD SDV Vent and Drain Valves Proposed Alternative in Accordance with 10 CFR 50.55a(z)(2) Hardship or Unusual Difficutty without a Compensating Increase in Level of Quality and Safety

1.

ASME Code Component(s) Affected Valve CRD-AOV-CV32A CRD-AOV-CV32B CRD-AOV-CV33 CRD-AOV-CV34 CRD-AOV-CV35 CRD-AOV.CV36 CRD-AOV-CV38A CRD-AOV-CV388 Category Class System CRD CRD CRD CRD CRD CRD CRD CRD B B B B B B B B 2 2 2 2 2 2 2 2 2.

===3. Applicable Code Edition and Addenda=== ASME OM Code 2022Ed1tion

Applicable Code Requirement

ISTC-3700, "Position Verification Testing," Valves with remote position indicators shall be observed locally at least once every 2 years to verify that valve operation is accurately indicated. Where practicable, this local observation should be supplernented by other indications such as use of flow meters or other suitable instrumentation to verify obturator movement. These observations need not be concurrent. Where local observation is not possible, other indications shall be used for verification of valve operation. 10CFR50.55a(b)(3)(xi), OM Condition: Valve Position Indication. When implementing paragraph ISTC-3700, "Position Verification Testing," in the ASME OM Code,2012 Edition through the latest edition of the ASME OM Code incorporated by reference in paragraph (a)(l)(iv) of this section, licensees must verify that valve operation is accurately indicated by supplementing valve position indicating lights with other indications, such as flow meters or other suitable instrumentation to provide assurance of proper obturator position for valves with remote position indication within the scope of Subsection ISTC including its mandatory appendices and their verification methods and frequencies. For valves not susceptible to stem-disk separation, licensees may implement ASME OM Code Case OMN-28, "Altemative Valve Position Verification Approach to Satisfy ISTC-3700 for Valves Not Susceptible to Stem-Disk Separation," which is incorporated by reference in paragraph (a)(1)(iii)ftI) of this section.

NLS20250I I Page 84 of9l Relief Request RV-05 Supplemental Position Indication Testing of CRD SDV Vent and Drain Valves (continued)

4.

Reason for Request

Pursuant to 10 CFR 50.55a, "Codes and Standards," paragraph(z)(2), relief is requested from the requirement of ISTC-3700 in accordance with condition 10CFR50.55a(b)(3)(xi) for the CRD System Scram Discharge Volume (SDV) vent and drain valves. The proposed alternative demonstrates that meeting this condition would be a hardship without a compensating increase in quality and safety. Due to the design of the CNS CRD system (reference Figure 1 simplifred diagram), the SDV vent and drain valves cannot be individually operated to perform supplemental position indication verification as required by the OM Condition in 10CFR50.55a(b)(3)(xi). Each of the vent and drain lines have two Code Class 2 AOVs in series, with no installed capability to verify individual valve obturator position with supplemental indications. Signifrcant plant design changes [e.g., redesigning the scram discharge instrument volume (SDIV) system] would be required as a part of a plant outage to be capable of performing the position indication testing in accordance with 10 CFR 50.55a(bX3Xxi).

5.

Proposed Alternative and Basis for Use The following CRD SDV vent and drain valves are paired together as indicated below for the South and North SDVs, as indicated. CRD-AOV-CY32A: 1" South SDV Inboard Vent Isolation Globe Valve CRD-AOV-CV38A: 1" South SDV Outboard Vent Isolation Globe Valve CRD-AOV-CV33: 2" South SDIV Inboard Drain Isolation Globe Valve CRD-AOV-CV35: 2" South SDIV Outboard Drain Isolation Globe Stop Valve CRD-AOV-CY32B: 1" North SDV Inboard Vent Isolation Globe Valve CRD-AOV-CV38B: 1" North SDV Outboard Vent Isolation Globe Valve CRD-AOV-CY34: 2" North SDIV Inboard Drain Isolation Globe Valve CRD-AOV-CV36: 2" North SDIV Outboard Drain Isolation Globe Stop Valve The CRD scram discharge volume vent and drain valves are normally open air-operated valves that fail to the closed position. The valves are all exercised with the same header of pressure to maintain the valves in the open position with air pressure on the header or to fail closed once the header pressure is exhausted. The air may be exhausted through venting from a Reactor Protection System (RPS) solenoid valve with input from "A" and "B" RPS, Alternate Rod Insertion (ARI) solenoid valves, or the air header may be exhausted by a test solenoid valve. In each case, all valves open and close simultaneously. During normal plant operation, each scram discharge header (North and South) is empty, and the drain and vent valves are open. A scram signal or ARI signal initiates the closure of the drain and

NLS202501 1 Page 85 of9l Relief Request RV-05 Supplemental Position Indication Testing of CRD SDV Vent and Drain Valves (continued) vent valves. There are two (2) valves in series on each Scram Discharge Volume (SDV) vent and drain. Position indicator switches on the vent and drain valves actuate valve lights in the Control Room. The limit switches for each series of valves are interconnected to provide positive indication that the vent and drain paths are either "open" or "closed". The close circuit limit switches for each set of valves are connected in parallel. Closure of either valve will produce the "close" light indication in the Control Room. This verifies that the vent and drain paths are isolated to prevent a potential uncontrolled loss of reactor coolant. The open circuit limit switches for each set of valves are wired in series, both valves must open in order for the "open" light indication in the Control Room to energize. This verifies that the vent and drain paths are open to prevent an undetected buildup of fluid in the SDV. Each SDV drains through an 8-inch line to a corresponding Scram Discharge Instrument Volume (SDIV). The two SDIVs have the instrumentation required to measure the amount of water accumulated in the SDVs. Two differential pressure level transmitters and three level-measuring switches set at the same low, intermediate, and high levels on each SDIV prevent operating the reactor without sufficient free volume present to accommodate the water discharged during a scram. At the first (lowest) level as water begins to fill either SDIV, the lower-level set point of the level transmitters will initiate alarms in the Control Room. At the second level, one level switch on each SDIV initiates a rod withdrawal block to prevent further withdrawal of any control rod. At the third (highest) level, a combination of the high-level set point of the level transmitters and the two remaining level switches on each SDIV initiates a scram to shut down the reactor while sufficient free volume is still present to receive the scram discharge water. Therefore, due to the design of the CNS CRD system, the SDV vent and drain valves cannot be individually operated to perform supplemental position indication verification as required by the OM Condition in 10CFR50.55a(b)(3)(xi). The system was designed to be operated in terms of vent and drain "paths" being open and closed versus two individual valves for each line being open and closed. Consequently, for the open position, local verification (e.g., limit switches, position indicators on the valve, valve stem travel) will be used to determine valve movement is accurately indicated by the remote position indicators (red lights) located in the main control room. With both valves on the vent or drain line verified to be open locally, the red light in the control room will be verified to be on for each path. Supplemental position verification of the SDV vent and drain valves in the open position will be satisfied by demonstrating the ability to maintain the SDV drained below applicable level alarm setpoints during unit operation. The three levels of alarms that an:runciate in the control room were previously described above. The continuous monitoring of SDV level provided by the system design provides supplemental verification that the open position of the SDV vent and drain valves is accurately indicated. The failure of a vent or drain valve path to isolate would be detected by indicating lights or SDV level increase, and there would be ample time and waming available to drain the SDV before an automatic scram would occur due to SDV high level.

NLS20250l l Page 86 of91 Relief Request RV-05 supplemental Position Indication Testing of cRD SDV vent and Drain valves (continued) For the closed position, local verification (e.g., limit switches, position indicators on the valve, valve stem travel) will be used to determine valve movement to the closed position is accurately indicated by the remote position indicators (green lights) located in the main control room. With one out of two valves on the vent or drain line closed and the other valve open, the green light for the associated line in the control room will be verified to be on. Supplemental position verification of the SDV vent and drain valves in the closed position will be satisfied by demonstrating annunciation of the SDIV high level alarm during a scram. The SDIV high level alarm demonstrates that each SDV vent and drain line path is physically isolated by at least one valve. The proposed alternative testing will be performed at the OM Code Subsection ISTC-3700 frequency of at least once every two years unless CNS adopts an ASME OM Code case (i.e.. OMN-

28) for these valves that would result in a modification to this frequency.

In conclusion, CNS is submitting this request for alternative in accordance with 10 CFR 50.55a(z)(2) since compliance with Subsection ISTC-3700 and I 0 CFR 50.55a(bX3Xxi) represents a hardship or unusual difficulty without a compensating increase in the level of quality and safety.

6.

Duration of Proposed Alternative This proposed altemative will be utilized for the entire Code of Record interval that uses the2022 Edition of the ASME oM code, beginning on March 1,2026, and ending on February 28th, 2050.

7.

Precedents A similar relief request was previously approved for the Browns Ferry Fifth ten-year interval as Relief Request BFN-IST-OI (EPID L-2022-LLR-0086, dated AugusL 17,2023),

NLS202501 I Page 87 of9l Relief Request RV-05 Supplemental Position Indication Testing of CRD SDV Vent and Drain Valves (continued) to A'I6ffNC actax vat Yta hih nikd 3l1234 raonh !nk.t tllztl Ll-L6ltann.r ul - l.Gl a-ilcrr Ax - Atrfr tddc Sovwvrtvt atIostfitf,E SCRAM DISCHARGE VOLUME f6ffi of Two Banks Shown) Figure 3, Rev. 10 tciax Klret YCUI Its a ita t coRms4& oiatx val Cs, SCiAr Prtot ttt vatvlt a,il I 6:la LT (2x l,5lal t7a SCiAt slcta^l. s rcD tto* <48' ita SCiAfl stct{At 3to. A 30Y taot DIAIICD E (rlop. den, Figure 1: CNS Simplified Diagram of CRD SDV Vent and Drain Configuration

NLS202501 I Page 88 of91 Relief Request RS-01 Grace Period for l0-Year Snubber Examinations Proposed Alternative in Accordance with 10 CFR 50.55a(z)(1) Alternative Provides Acceptable Level of Quality and Safety

1.

ASME Code Component(s) Affected All snubbers within the scope of American Society of Mechanical Engineers (ASME) Code for Operation and Maintenance (OM) of Nuclear Power Plants, ISTA-1100. 53 ANVIL/Grinnell Hydraulic Snubbers 18 PSA-3 Mechanical Snubbers 89 PSA-10 Mechanical Snubbers 48 PSA-35 Mechanical Snubbers

2.

Applicable Code Edition and Addenda

American Society of Mechanical Engineers (ASME) Code for Operation and Maintenance of Nuclear Power Plants (OM Code) 2022Edition.

3.

Applicable Code Requirement

ISTA-3170 Inservice Examination and Test Frequency Grace. The fourth paragraph in ISTA-3170(a)(3) states that "Period extensions may not be applied to the test frequency requirements specified in Subsection ISTD, as Subsection ISTD contains its own rules for period extensions." Table ISTD-4252-I Visual Examination Table, the last sentence in Note (7) states that "No grace period extension is applicable to extend any visual examination beyond 10 yr."

4.

Reason for Request

Pursuant to 10 CFR 50.55a, "Codes and Standards," paragraph (z)(1), reliefis requested from the requirement of ASME OM Code ISTA-3170 and Table ISTD-4252-1, Note (7). The proposed alternative would provide an acceptable level of quality and safety. A grace period allowance for the snubber 1O-year examination interval for each individual snubber is currently not allowed per Note (7) of Table ISTD-4252-1. Because of this, CNS would be implementing a less efficient overall program for the mechanical snubbers, as explained in section 5, and would be required to perform many mechanicaVhydraulic snubber examinations on a four refueling cycle interval rather than every five refueling cycles due to the potential to exceed the 10-year examination interval by only a few days. The proposed alternative will allow CNS to continue to implement an effective snubber program in an efficient manner with no impact on snubber performance.

NLS202501 I Page 89 of9l Relief Request RS-01 Grace Period for l0-Year Snubber Examinations (Continued)

5.

Proposed Alternative and Basis for Use CNS is proposing a grace period to the ISTD snubber examination interval of 10 years for each individual snubber. For the reasons provided in the following paragraphs, CNS proposes that for any snubber examination coming due during a snubber refueling outage campaign period (92 days prior to the start of the refueling outage up to plant startup), the examination shall be completed prior to plant startup for that refueling outage. This time frame is in alignment with the test campaign frequency specified in ISTD-5240, which is also the typical time frame utilized for snubber examinations at CNS. Performing examinations within this period each refueling outage would result in a worst-case grace period of approximately 120 days (92 days prior to the start of the refueling outage plus the duration of the refueling outage). Therefore, CNS is requesting a grace period not to exceed 120 days for the ISTD l0-year snubber examination interval. CNS began utilizing ISTD and Code Case OMN-I3 in refueling outage RE2a (Spring/2008). At that time, the operating cycles were 18 months long. Following the refueling outage in the Fall of 2012 (RF,27), CNS began its first 24-monthoperating cycle. Therefore, RE32 (Fall of 2022) represented the first refueling outage in which the full 24-monthinterval has occurred for five continuous cycles. Grace periods for the 10-year snubber examination interval for RE32 (Fall of 2022) and RE33 (Fall of 2024) were previously approved as relief request RS-l for the Fifth Ten-Year Interval. This relief request represents a continuation of that relief request for the upcoming Code of Record Interval, beginning with refueling outage RE34 (Fall of 2026). Therefore, snubber examinations that were performed in September/October of 2016 (Pre-RE29 or during RE29) would be due exactly 10 years later in September/October of 2026 (Pre-RE34 or during RE34) with no grace period allowed. Similar strict l0-year examination interval requirements for each individual snubber would occur for the remaining refueling outages throughout the Code of Record Interval. To maintain the snubber examinations on a five refueling cycle interval and still meet the Subsection ISTD lO-year frequency with no grace, the examinations would have to be carefully scheduled and monitored to ensure the l0-year interval for each one was not exceeded prior to the completion of each examination. In some cases, the snubber examination(s) would be required to be scheduled during times when specific systems are taken out of service, which limits the flexibility in scheduling. Also, delays may occur during the refueling outage (i.e. due to emergent issues, higher priority items, scheduling conflicts, resource issues, etc.), which could potentially move out the initial scheduled date to slightly past the 10-year date required per Subsection ISTD. The time and resources to monitor these activities to this degree are not necessary. Performing a snubber examination at 10 years or slightly over 10 years during the same scheduled snubber refueling outage campaign will not impact program effectiveness. Any actions required prior to plant startup per ISTD would still be implemented in the same manner. Another basis for pursuing this relief request is the aggressive service life monitoring approach taken at CNS for the mechanical snubbers within the program. Mechanical snubbers represent approximately 74.5% of the CNS snubber program scope (155 out of 208). Although the vendor design life of the mechanical snubbers is 40 years, due to the potential impact from vibration,

NLS202501 I Page 90 of91 Relief Request RS-01 Grace Period for l0-Year Snubber Examinations (Continued) heat, and radiation, CNS performs a service life snubber activity after approximately 10 years in service for all mechanical snubbers. This approach has resulted in an excellent performance history for the mechanical snubbers. For efficiency pu{poses, this service life monitoring activity for mechanical snubbers is completed following the as found ISTD examinations. Generally, the snubber is replaced with a pretested, rebuilt mechanical snubber and the removed snubber is as-found tested and retumed to spares to be rebuilt at a future date. As a minimum, the snubber is removed, tested, and re-installed. Historically, this service life activity,for mechanical snubbers has proven to be very effective in the overall performance of the mechanical snubbers at the l0-year frequency, so performing this service life activity at slightly greater than 10 years would be an acceptable practice. Therefore, it is not desirable to move this activity to eight years (four refueling cycles) to ensure that the l0-year ISTD examination frequency with no grace is met. Also, performing the ISTD examination approximately every eight years to ensure that the ISTD frequency is met, and the service life monitoring activity approximately every 10 years would not be effrcient. Over the life of the plant, performing the examination and service life monitoring activity every four refueling cycles or performing them independently at different intervals would increase resources and radiological dose with no compensating increase in quality or safety. In addition, the examination and test results of these service life maintenance activities are inputs to the snubber service life evaluation that is being performed at least once each fuel cycle in accordance with ISTD-6000, Service Life Monitoring. Hydraulic snubbers represent approximately 255% of the snubber program scope at CNS (53 out of 208 snubbers). The current service life of the hydraulic snubbers at CNS is 25 years. Howevet, for the same reasons as discussed above and because they are more likely to be examined during the pre-outage time frame due to their locations, many of them may need to be scheduled to be examined once every 4 refueling outages rather than once every 5 refueling outages to meet the ISTD l0-year examination interval for each hydraulic snubber. Having to perform the examinations more frequently than once every 5 refueling outages is less efficient since cNS has had an excellent performance history for the hydraulic snubbers. CNS has implemented individual snubber examination frequencies of at least once every 10 years since the Spring of 2008 and no programmatic snubber examination failures and/or test failures have occurred during this period. Additionally, no significant degradation or anomalies have been identified. This success is expected to continue with the proposed altemative. Therefore, allowing the ISTD lO-year examination frequency to extend slightly beyond 10 years will have a negligible impact on the examination results and will allow CNS to continue to implement an effective service life program for mechanical snubbers. CNS will continue to follow l0cFR50.55a(b)(3)(vii), OM Condition: Snubber visual examination interval extension. When implementing Subsection ISTD, paragraph ISTD-4253, and Note 7 of Table ISTD-4252-1, in the 2022Edirion of the ASME OM Code, incorporated by reference in paragraph (aXl) of this section, to extend snubber visual examination beyond two refueling cycles (48 months), the licensee is prohibited from applying OM Code Case OMN-15, Revision 2, to extend the operational readiness testing of snubbers.

NLS202501 I Page 91 of91 Relief Request RS-01 Grace Period for l0-Year Snubber Examinations (Continued) In conclusion, CNS proposes a grace period not to exceed 120 days for the ISTD l0-year examination interval for each individual snubber. For the reasons provided, this alternative will provide an acceptable level of quality and safety for the snubbers at CNS pursuant to 10CFR50.ssa(z)(1).

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Duration of Proposed Alternative This proposed alternative will be utilized for the entire Code of Record interval that uses the 2022 Edition of the ASME oM code, beginning on March 1,2026, and ending on February 28th, 20s0.

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Precedents This relief request was previously approved for the last portion of the fifth ten-year interval at CNS as RS-01 (EPID L-2021-LLR-0044, dated July 21,2022).}}