RA-24-0137, Relief Requests for Inservice Testing Plan – Fifth Interval
| ML24183A198 | |
| Person / Time | |
|---|---|
| Site: | McGuire, Mcguire  |
| Issue date: | 07/01/2024 |
| From: | Ellis K Duke Energy Carolinas |
| To: | Office of Nuclear Reactor Regulation, Document Control Desk |
| References | |
| RA-24-0137 | |
| Download: ML24183A198 (1) | |
Text
Kevin M. Ellis General Manager Nuclear Regulatory Affairs, Policy &
Emergency Preparedness Duke Energy 13225 Hagers Ferry Rd., MG011E Huntersville, NC 28078 843-951-1329 Kevin.Ellis@duke-energy.com Serial: RA-24-0137 10 CFR 50.55a July 1, 2024 U.S. Nuclear Regulatory Commission ATTN: Document Control Desk Washington, DC 20555-0001 McGuire Nuclear Station, Unit Nos. 1 and 2 Docket Nos. 50-369 and 50-370 / Renewed License Nos. NPF-9 and NPF-17
SUBJECT:
Relief Requests for Inservice Testing Plan - Fifth Interval Ladies and Gentlemen:
Pursuant to 10 CFR 50.55a(z)(1), Duke Energy Carolinas, LLC (Duke Energy) is submitting two relief requests to the Nuclear Regulatory Commission (NRC) for approval for McGuire Nuclear Station, Units 1 and 2 (MNS). Duke Energy is seeking approval of the relief requests for use during the fifth ten-year inservice testing (IST) program, which begins on March 1, 2025.
10 CFR 50.55a(f)(4)(ii) requires that IST programs conducted during successive ten-year inspection intervals following the initial ten-year interval comply with the requirements of the latest edition and addenda of the Code, incorporated by reference in paragraph (a)(1)(iv) of 10 CFR 50.55a, eighteen months prior to the start of the ten-year interval, subject to the conditions listed within paragraph (b) of that section. Therefore, the MNS fifth interval IST plan will be based on the requirements of the ASME Code for Operation and Maintenance of Nuclear Power Plants (ASME Code), 2020 Edition. Accordingly, the enclosed relief requests are sought from the requirements of the 2020 Edition of the ASME Code.
The relief requests are contained as Enclosures 1 and 2 of this submittal.
In order to support implementation of the fifth ten-year interval IST program, Duke Energy requests NRC approval of the enclosed relief requests by February 14, 2025.
U.S. Nuclear Regulatory Commission RA-24-0137 Page2 No new regulatory commitments have been made in this submittal. If you have addltional questions, please contact Ryan Treadway, Director - Nuclear Fleet Licensing, at 980-373-5873.
Sincerely,
~
General Manager - Nuclear Regulatory Affairs, Policy & Emergency Preparedness
Enclosures:
cc:
- 1. Relief Request MC-SRP-KC-01
- 2. Relief Request MC-SRP-ND-01 L. Dudes, Regional Administrator USNRC Region II C. Safouri, NRC Senior Resident Inspector J. Klos, NRC Project Manager, NRR RA-24-0137 Relief Request MC-SRP-KC-01 3 Pages Follow
10 CFR 50.55a Relief Request Number MC-SRP-KC-01 Proposed Alternative in Accordance with 10 CFR 50.55a(z)(1)
Alternate Provides Acceptable Level of Quality and Safety of RA-24-0137 Page 1 of 3
- 1.
ASME Code Components Affected Component ID Pump Description ASME Class ASME OM Code Category 1KCPU0001 1A1 Component Cooling Pump 3
Group A 1KCPU0002 1A2 Component Cooling Pump 3
Group A 1KCPU0003 1B1 Component Cooling Pump 3
Group A 1KCPU0004 1B2 Component Cooling Pump 3
Group A 2KCPU0001 2A1 Component Cooling Pump 3
Group A 2KCPU0002 2A2 Component Cooling Pump 3
Group A 2KCPU0003 2B1 Component Cooling Pump 3
Group A 2KCPU0004 2B2 Component Cooling Pump 3
Group A Function:
Component Cooling (KC) pumps provide flow to their respective KC trains. Each pump shall start automatically upon receipt of a Safety Injection (NI) signal (Ss) to supply cooling water to the KC System essential header (ND heat exchangers 1/2A and B and ND pump mechanical seal cooling water heat exchangers 1/2A and B) to mitigate the consequences of an accident upon Emergency Core Cooling System (ECCS) actuation.
- 2.
Applicable Code Edition and Addenda
American Society of Mechanical Engineers (ASME) Operation and Maintenance of Nuclear Power Plants (OM) Code, 2020 Edition.
- 3.
Applicable Code Requirement
ISTB-3500, Data Collection and ISTB-3510 General paragraph (a) Accuracy. Instrument accuracy shall be within the limits of Table ISTB-3510-1. If a parameter is determined by analytical methods instead of measurement, then the determination shall meet the parameter accuracy requirement of Table ISTB-3510-1 (e.g.,
flow rate determination shall be accurate to within +/-2% of actual). For individual analog instruments, the required accuracy is percent of full-scale. For digital instruments, the required accuracy is over the calibrated range. For a combination of instruments, the required accuracy is loop accuracy.
(b) (1) The full-scale range of each analog instrument shall not be greater than three times the reference value.
Table ISTB-3510-1, Required Instrument Accuracy provides the accuracy requirements for gauges used for Group A Testing requirements for pumps.
10 CFR 50.55a Relief Request Number MC-SRP-KC-01 Proposed Alternative in Accordance with 10 CFR 50.55a(z)(1)
Alternate Provides Acceptable Level of Quality and Safety of RA-24-0137 Page 2 of 3
- 4.
Reason for Request
Pursuant to 10 CFR 50.55a(z)(1), relief is requested from the requirements of the ASME OM Code, 2020 Edition, Subsection ISTB-3510(b)(1) for instrument range requirements for Group A Tests. Comprehensive Testing will be performed using temporarily installed test instruments (M&TE) to meet the requirements for comprehensive pump testing instrument accuracy.
The Unit 1 Component Cooling Water Pumps have suction pressure gauges with a range of 0-60 psig and typical pressure readings of 13-16 psig. The Unit 2 Component Cooling Water Pumps have suction pressure gauges 0-30 psig and typical pressure readings of 8.5-10.5 psig. As such, there are times when the three times the reference range cannot be met.
- 5.
Proposed Alternative and Basis for Use The installed process instrumentation will be used to measure KC pump suction pressure.
As previously stated, the Unit 1 KC pump suction gauges are 0-60 psig and the Unit 2 KC pump suction gauges are 0-30 psig. During the fifth ten-year inservice testing (IST) interval, the accuracy of these gauges will be 0.5% for Unit 1 and 1% for Unit 2.
The KC pumps are tested quarterly (Group A) and biennially (Comprehensive) as required by the IST Program. The proposed alternative is for the Group A test only. The Comprehensive test is performed using temporarily installed test instruments (M&TE) to meet the requirements for comprehensive pump testing instrument accuracy.
Typical Unit 1 suction pressure readings during the Group A KC pump test are between 13-16 psig; therefore, the Unit 1 suction pressure gauges do not meet the three times criterion. The accuracy of the Unit 1 KC suction gauges (0.5%) is well within the requirements specified in Table ISTB-3510-1 for pressure instrument accuracy (2%). A gauge that meets the Code requirements of three times at 2% accuracy results in a reading error of 6% uncertainty (2*3x/x=6%). The actual reading error, given the 0.5% calibration of the 0-60 psig gauge, would satisfy the Code equivalent 6% uncertainty at suction pressures of 5 psig and higher (60/5*0.005=6%). Therefore, for Unit 1, Code equivalent 6%
uncertainty suction pressures can be obtained during Group A KC pump testing using the 0-60 psig range gauges with a 0.5% of Full-Scale calibration.
Typical Unit 2 suction pressure readings during the Group A KC pump test are between 8.5-10.5 psig; therefore, the Unit 2 suction pressure gauges do not meet the three times criterion. The accuracy of the Unit 2 KC suction gauges (1%) is well within the requirements specified in Table ISTB-3510-1 for pressure instrument accuracy (2%). The actual reading error, given the 1% calibration of the 0-30 psig gauge, would satisfy the Code equivalent 6% uncertainty at suction pressures of 5 psig and higher (30/5*0.01=6%). Therefore, for Unit 2, Code equivalent 6% uncertainty suction pressures can be obtained during Group A KC pump testing using the 0-30 psig range gauges with a 1.0% of Full Scale calibration.
When the requirements of 2020 ISTB-3500 and Table ISTB-3510-1 are combined, the actual instrument error introduced for suction pressure is less than the code allowable (6%), given the Full-Scale calibrations used on Unit 1 (0.5%), and Unit 2 (1.0%). Using the process instrument for suction pressure data does not degrade the quality of the test and meets the overall intent of the instrumentation requirements of the OM Code; just not the specific range requirements of 2020 Edition of ISTB-3510(b)(1).
10 CFR 50.55a Relief Request Number MC-SRP-KC-01 Proposed Alternative in Accordance with 10 CFR 50.55a(z)(1)
Alternate Provides Acceptable Level of Quality and Safety of RA-24-0137 Page 3 of 3 Using the provisions of this request would provide adequate detection of component degradation and, would continue to provide reasonable assurance of the operational readiness of affected MNS Component Cooling Water Pumps. Therefore, the alternative test equipment would result in an acceptable level of quality and safety pursuant to 10 CFR 50.55a(z)(1) during Group A tests.
- 6.
Duration of Proposed Alternative This relief will be implemented during the MNS, Fifth Ten-Year Inservice Testing Interval for the KC Component Cooling Water System pumps required by ASME OM Code, 2020 Edition, Subsection ISTB, which starts on March 1, 2025.
- 7.
Precedents ADAMS Accession No. ML14013A242, McGuire Nuclear Station, Units 1 and 2: Proposed Relief Request Nos. MC-SRP-KC-01 and MC-SRP-ND-01 (TAC Nos. MF1164, MF1165, MF1166 and MF1167).
This precedent contains the same proposed alternative for the MNS Fourth Ten-Year Inservice Testing Interval. The justification in this Fifth Interval proposed alternative utilizes the same concepts as that presented in the precedent, although some rephrasing has taken place for clarification. In addition, some gauge ranges and accuracies have changed but the overall conclusion is not impacted.
- 8. References
- 1. ASME OM Code, 2020 Edition, Operation and Maintenance of Nuclear Power Plants RA-24-0137 Relief Request MC-SRP-ND-01 3 Pages Follow
10 CFR 50.55a Relief Request Number MC-SRP-ND-01 Proposed Alternative in Accordance with 10 CFR 50.55a(z)(1)
Alternate Provides Acceptable Level of Quality and Safety of RA-24-0137 Page 1 of 3
- 1.
ASME Code Components Affected Component ID Pump Description ASME Class ASME OM Code Category 1NDPU0001 1A Residual Heat Removal Pump 2
Group A 1NDPU0002 1B Residual Heat Removal Pump 2
Group A 2NDPU0001 2A Residual Heat Removal Pump 2
Group A 2NDPU0002 2B Residual Heat Removal Pump 2
Group A Function:
The Residual Heat Removal (ND) pumps provide flow to the ND heat exchangers and support removal of residual heat during the hot and cold shutdown modes of normal operation. The ND pumps support operation of the Emergency Core Cooling System (ECCS) in cooling the reactor core and controlling reactivity following Large-Break Loss of Coolant Accidents (LOCAs). These pumps actuate on Safety Injection (NI) signal and deliver borated water from the Refueling Water Storage Tank (FWST) to the Reactor Coolant (NC) system. The injected water offsets inventory loss due to LOCAs. The injected boron provides an addition of negative reactivity to maintain the reactor subcritical following a LOCA.
- 2.
Applicable Code Edition and Addenda
American Society of Mechanical Engineers (ASME) Operation and Maintenance of Nuclear Power Plants (OM) Code, 2020 Edition.
- 3.
Applicable Code Requirement
ISTB-3500, Data Collection and ISTB-3510 General' paragraph (a) Accuracy. Instrument accuracy shall be within the limits of Table ISTB-3510-1. If a parameter is determined by analytical methods instead of measurement, then the determination shall meet the parameter accuracy requirement of Table ISTB-3510-1 (e.g.,
flow rate determination shall be accurate to within +/-2% of actual). For individual analog instruments, the required accuracy is percent of full-scale. For digital instruments, the required accuracy is over the calibrated range. For a combination of instruments, the required accuracy is loop accuracy.
(b) (1) The full-scale range of each analog instrument shall not be greater than three times the reference value.
Table ISTB-3510-1, Required Instrument Accuracy provides the accuracy requirements for gauges used for Group A Testing requirement for pumps.
10 CFR 50.55a Relief Request Number MC-SRP-ND-01 Proposed Alternative in Accordance with 10 CFR 50.55a(z)(1)
Alternate Provides Acceptable Level of Quality and Safety of RA-24-0137 Page 2 of 3
- 4.
Reason for Request
Pursuant to 10 CFR 50.55a(z)(1), relief is requested from the requirements of the ASME OM Code, 2020 Edition, Subsection ISTB-3510(b)(1) for instrument range requirements for Group A Tests. Comprehensive Testing will be performed using temporarily installed test instruments (M&TE) to meet the requirements for comprehensive pump testing instrument accuracy.
The Residual Heat Removal pumps have process instrumentation installed such that there are two suction pressure gauges (0-60 psig and 0-600 psig), and one discharge pressure gauge, (0-1000 psig). Each has 0.5% accuracy. This is done to provide accurate pressure indication in either the recirculation or the heat removal condition of operation. Typical suction pressure readings are 48-81 psig and typical discharge pressure readings are 230-260 psig. As such, there are times when three times the reference range requirements cannot be met.
- 5.
Proposed Alternative and Basis for Use The installed process instrumentation will be used to measure ND pump suction and discharge pressure. As previously stated, there are two suction pressure gauges (0-60 psig and 0-600 psig), and one discharge pressure gauge, (0-1000 psig). Each has 0.5%
accuracy.
The ND pumps are tested quarterly (Group A) and biennially (Comprehensive) as required by the IST Program. The proposed alternative is for the Group A test only. The Comprehensive test is performed using temporarily installed test instruments (M&TE) to meet the requirements for comprehensive pump testing instrument accuracy.
Typical values for ND pump suction pressure during the Group A test are 48-81 psig.
Therefore, there is a range (>60 psig) in which the 0-600 psig gauge is required and will not meet the three times criteria. The accuracy of this process instrument (0.5%) is well within the requirements specified in Table ISTB-3510-1 for instrument accuracy (2% for Group A tests). A gauge that meets the Code requirements of three times at 2% accuracy results in a reading error of 6% uncertainty (2*3x/x=6%). The actual reading error, given the 0.5%
calibration of the 0-600 psig gauge, would satisfy the Code equivalent 6% uncertainty at suction pressures of 50 psig and higher (600/50*0.005=6%). Therefore, Code equivalent 6% uncertainty suction pressures can be obtained during Group A ND pump testing using the 0-600 psig range gauge with a 0.5% of Full-Scale calibration. For pressures below 50 psig the tighter range (0-60psig) suction pressure gauge shall be used which meets all ASME Code requirements for range and accuracy.
Typical values for ND pump discharge pressures during the Group A test are 230-260 psig.
Therefore, the process range for the discharge pressure gauge (0-1000 psig) will not meet the three times criteria. The accuracy of this process instrument (0.5%) is well within the requirements specified in Table ISTB-3510-1 for instrument accuracy (2% for Group A tests). The actual reading error, given the 0.5% calibration, would satisfy the Code equivalent 6%
uncertainty at discharge pressures of 84 psig and higher (1000/84*0.005=6%). Therefore, Code equivalent 6% uncertainty discharge pressures can be obtained during Group A ND pump testing using the 0-1000 psig range gauge with a 0.5% of Full-Scale calibration.
10 CFR 50.55a Relief Request Number MC-SRP-ND-01 Proposed Alternative in Accordance with 10 CFR 50.55a(z)(1)
Alternate Provides Acceptable Level of Quality and Safety of RA-24-0137 Page 3 of 3 When the requirements of 2020 ISTB-3500 and Table ISTB-3510-1 are combined, the actual instrument error introduced for suction and discharge pressure is less than the code allowable (6%), given the Full-Scale calibrations of 0.5%. Using the process instruments for the ND pumps pressure data does not degrade the quality of the test and meets the overall intent of the instrumentation requirements of the OM Code; just not the specific range requirements of 2020 Edition of ISTB-3510(b)(1).
Using the provisions of this request would provide adequate detection of component degradation and would continue to provide reasonable assurance of the operational readiness of affected MNS Residual Heat Removal Pumps. Therefore, the alternative test equipment would result in an acceptable level of quality and safety pursuant to 10 CFR 50.55a(z)(1) during Group A tests.
- 6.
Duration of Proposed Alternative This relief will be implemented during the MNS, Fifth Ten-Year Inservice Testing Interval for the ND Residual Heat Removal System pumps required by ASME OM Code, 2020 Edition, Subsection ISTB, which starts on March 1, 2025.
- 7.
Precedents ADAMS Accession No. ML14013A242, McGuire Nuclear Station, Units 1 and 2: Proposed Relief Request Nos. MC-SRP-KC-01 and MC-SRP-ND-01 (TAC Nos. MF1164, MF1165, MF1166 and MF1167).
This precedent contains the same proposed alternative for the MNS Fourth Ten-Year Inservice Testing Interval. The justification in this Fifth Interval proposed alternative utilizes the same concepts as that presented in the precedent, although some rephrasing has taken place for clarification.
- 8. References