ML102730397
ML102730397 | |
Person / Time | |
---|---|
Site: | Kewaunee ![]() |
Issue date: | 03/30/2010 |
From: | Baugus A, Valerie Myers Dominion Energy Kewaunee |
To: | Office of Nuclear Reactor Regulation |
References | |
EE-0116, Rev 7 | |
Download: ML102730397 (212) | |
Text
Technical Report Cover Sheet EE 0116, Rev. 7 w
i~I,I!lmf8_mmmmmll TECHNICAL REPORT No. EE-0116, REVISION 7 ALLOWABLE VALUES FOR NORTH ANNA IMPROVED TECHNICAL SPECIFICATIONS (ITS) TABLES 3.3.1-1 AND 3.3.2..1, SETTING LIMITS FOR SURRY CUSTOM TECHNICALSPECIFICATIONS (CTS), SECTIONS 2.3 AND 3.7, AND ALLOWABLE VALUES FOR KEWAUNEE POWER STATION IMPROVED TECHNICAL SPECIFICATIONS (ITS) FUNCTiONS LISTED IN SPECIFICATION 5.5.16 NORTH ANNA POWER STATION, SURRY POWER STATION, AND KEWAUNEE POWER STATION CORPORATE ELECTRICAUI&C/COMPUTERS DOMINION NUCLEAR ENGINEERING March 2010 Prepared By: h.".'" .~o.-~
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Key Words; Allowable Values As Found Toleranoes ESFAS Instrumentation Improved Teohnlcal Specifioations Limiting Safety System Settings Reactor Protection System Instrumentation Setting limits Setpoints (June 2006)
EE-0116 Revision 7 Record of Revision Rev 0 Original Issue.
Rev 1 1 Changed the calculation of the Allowable Values for North Annas High Steam Flow in 2/3 Steam Lines ESFAS initiation on Page 23. The revised Allowable Values are based on using only 1 Rack Drift (RD) term for the function. This change yields more conservative Allowable Values.
- 2. Changed the calculation of the Allowable Values for Surrys High Steam Flow in 2/3 Steam Lines ESFAS initiation on Pages 29 and 30. The revised Allowable Values are based on using only 1 Rack Drift (RD) term for the function. This change yields more conservative Allowable Values.
- 3. Changed the Allowable Values and verbiage on Page 42 for the North Anna High Steam Flow in 2/3 Steam Lines ESFAS initiation.
- 4. Deleted the Allowable Values for the enable manual block of Safety Injection for North Anna Permissives P-11 and P-12 and revised the verbiage accordingly on Page 47.
- 5. Changed the Allowable Values and verbiage on Page 56 for the Surry High Steam Flow in 2/3 Steam Lines ESFAS initiation.
- 6. Deleted the Allowable Values for the enable manual block of Safety Injection for Surry Permissives P-11 and P-12 and revised the verbiage accordingly on Page 63.
Rev 2 1. Page 16 - Changed Rack Drift term RD4 from 1.0 % span to 0.0 % span in Figure 3.2-5 to obtain a more conservative Allowable Value for the OTT Reactor Trip Setpoint.
- 2. Page 18 - Changed Rack Drift term RD4 from 1.0 % span to 0.0 % span to be consistent with Calculation EE-0415. This change yields a more conservative Allowable Value for the OTT Reactor Trip Setpoint.
- 3. Page 24 - Changed Rack Drift term RD4 from 1.0 % span to 0.0 % span in Figure 3.3-2 to obtain a more conservative Allowable Value for the OTT Reactor Trip Setpoint.
- 4. Page 25 - Changed Rack Drift term RD4 from 1.0 % span to 0.0 % span to be consistent with Calculation EE-0434. This change yields a more conservative Allowable Value for the OTT Reactor Trip Setpoint.
- 5. Pages 25 and 26 - Revised calculations shown in Methods 1a through 2b based on Rack Drift Term RD4 = 0.0 % span.
- 6. Page 31 - Changed Rack Drift term RD4 from 1.0 % span to 0.0 % span in Figure 3.3-4 to obtain a more conservative Allowable Value for the OPT Reactor Trip Setpoint.
- 7. Page 32 - Changed Rack Drift term RD4 from 1.0 % span to 0.0 % span to be consistent with Calculation EE-0415. This change yields a more conservative Allowable Value for the OPT Reactor Trip Setpoint. The Allowable Value calculation shown on Page 32 was revised based on RD3 = 0.0 % span.
i
EE-0116 Revision 7
- 8. Pages 34 and 35 - Revised NAPS OTT Reactor Trip Allowable Value and associated verbiage in Item 4.1.8.
- 9. Page 47 - Added another Allowable Value for NAPS Permissive P-12 and revised associated verbiage in Item 4.2.38.
- 10. Page 49 - Revised SPS OTT Reactor Trip Allowable Value and associated verbiage in Item 4.3.6.
- 11. Page 49 - Revised verbiage associated with the SPS OPT Reactor Trip Allowable Value in Item 4.3.7.
- 12. Page 63 - Added another Allowable Value for SPS Permissive P-12 and revised associated verbiage in Item 4.4.42.
Rev 3 Revision 3 to this Technical Report is a major revision. The Allowable Values for North Annas ITS and the Setting Limits for Surrys CTS are derived and based on Methods 1 or 2 as described in Part II of ISA-RP67.04.02-2000. This revision will require a complete review from cover to cover. This Technical Report will be used as the design basis for Technical Specifications Change Request 318 at Surry Power Station. In addition, this Technical Report will also be used as the design input for a future Technical Specifications Change Request for North Anna to change selected Allowable Values as noted in this report.
In accordance with NDCM 3.11 the Required Actions and Tracking Mechanism will be documented in Engineering Transmittal ET-CEE-06-0020, Rev. 0 Transmittal of CDS and PRC for Technical Report EE-0116, Rev. 3. In addition, the results of Technical Report EE-0116, Rev. 3 will be screened as part of ET-CEE-06-0020, rev. 0 and will not be repeated herein.
Rev 4 1. Page 5 - Added Cot or Non-Cot to the error terms in Table 2.1.
- 2. Page 9 - Changed the wording under item 3 to reflect that some Allowable Values have been rounded as per discussions with the NRC and Surry TSCR 318.
- 3. Page 13 - Changed the Rack Error Terms for M1MTE and M5MTE due to the revised CSA calculation EE-0063.
- 4. Page 33 - Changed the Power Range Neutron Flux High Setpoint Reactor Trip due to the revised CSA calculation EE-0063.
- 5. Page 34 - Changed Figure 4.1.2 for the Power Range Neutron Flux High Reactor Trip and changed the Power Range Neutron Flux Low Setpoint Reactor Trip due to the revised CSA calculation EE-0063.
- 6. Page 35 - Changed Figure 4.1.3 for the Power Range Neutron Flux Low Setpoint Reactor Trip due to the revised CSA calculation EE-0063.
- 7. Page 45 - Changed the Pressurizer High Pressure Reactor Trip due to the Safety Analysis Limit being changed from 2381.3 PSIG to 2391.3 PSIG based on ET-NAF-08-0061.
- 8. Page 47 - Changed Figure 4.1.10 for the Pressurizer High Pressure Reactor Trip due to the Safety Analysis Limit being changed from 2381.3 PSIG to 2391.3 PSIG based on ET-NAF-08-0061.
ii
EE-0116 Revision 7
- 9. Page 48 - Changed the Reactor Coolant Flow Low Reactor trip due to the revised CSA calculation EE-0060.
- 10. Page 49 - Changed Figure 4.1.12 for Low Reactor Coolant Flow Reactor Trip due to the revision of CSA calculation EE-0060.
- 11. Page 53 - Changed the Permissive P-8, Power Range Neutron Flux due to the revised CSA calculation EE-0063.
- 12. Page 54 - Changed Figure 4.1.24 for the Power Range Reactor Trip Permissive P-8 due to the revised CSA calculation EE-0063.
- 13. Page 57 - Changed Figure 4.2.3 for Containment Pressure HI-1 ESFAS Initiation due to the revised Containment Partial Pressure operating Limits per Technical Report NE-1472, Revision 0.
- 14. Page 62 - Changed the TAVG Low-Low ESFAS Initiation due to the revised CSA calculation EE-0434.
- 15. Page 64 - Changed Figure 4.2.7 for TAVG Low Low ESFAS Initiation due to the revised CSA calculation EE-0434.
- 16. Page 68 - Changed Figure 4.2.11 for Containment Pressure HI-3 ESFAS Initiation due to the revised Containment Partial Pressure operating Limits per Technical Report NE-1472, Revision 0.
- 17. Page 71 - Changed Figure 4.2.20 for Containment Pressure HI-2 ESFAS Initiation due to the revised Containment Partial Pressure operating Limits per Technical Report NE-1472, Revision 0.
- 18. Page 75 - Deleted the Analysis for > 19.0 % Wide Range Level and the Analysis for < 20.0 Wide Range Level for the Refueling Water Storage Tank Level - Low Low. With the implementation of DCP 06-013 and 06- 015 these analysis are no longer valid.
- 19. Page 77 - Deleted Figure 4.2.34a. This Figure is no longer applicable with the implementation of DCP 06-013 and 06-015. Changed Figure number to 4.2.34.
- 20. Page 78 - Changed the TAVG, P-12 ESFAS Permissive due to the revised CSA calculation EE-0434.
- 21. Page 79 - Changed Figure 4.2.38 for ESFAS Permissive P-12 due to the revised CSA calculation EE-0434.
- 22. Page 103 - Incorporated Addendum 1 for the Turbine First Stage Pressure Input to Permissive P-7.
- 23. Page 106 - Changed the word or to and for Permissive P-10, Power Range Neutron Flux.
- 24. Page 107 - Changed the Containment Pressure - High, Engineered Safety Features Actuation System (EFAS) Instrumentation Setting Limits due to the revised Safety Analysis Limits in Technical Report NE-0994, Revision 15.
iii
EE-0116 Revision 7
- 25. Page 108 - Changed Figure 4.4.2 for the new Safety Analysis Limit from Technical Report EE-0994, Revision 15 and updated operating limits per Technical Report NE-1460, Revision 1.
- 26. Page 119 - Determined the Voltage and Time corresponding to the new Allowable Value for Low Intake Canal Level.
- 27. Page 122 - Changed the Refueling Water Storage Tank Level Low - Low RMT Initiation, EFAS Instrumentation Setting Limits due to the revised Safety Analysis Limits in Technical Report NE-0994, Revision 14.
- 28. Page 124 - Changed Figure 4.4.12 due to the revised Safety Analysis Limit in technical Report NE-0994, Revision 14.
- 29. Page 128 - Changed References 5.1, 5.2, and 5.15 to reflect the current revision.
- 30. Page 129 - Changed References 5.18, 5.21, 5.23, 5.26, 5.27, 5.33 to reflect the current revision.
- 31. Page 130- Changed References 5.35, 5.36, 5.40, 5.41, 5.44 through 5.62 to reflect the current revision.
- 32. Page 132 - Changed References 5.63 through 5.65 and 5.67 through 5.69 to reflect the current revision. Deleted Reference 5.77.
- 33. Page 133 - Changed References 5.80 through 5.82 to reflect the current revision. Added Reference 5.88, ET-NAF-08-0061, Rev. 0 Implementation of Revised Safety Analysis Limit for High Pressurizer Pressure Reactor Trip, North Anna Units 1 and 2.
Rev. 5 Revision 5 to this Technical Report is a major revision. Kewaunee Power Stations Setpoint Control Program has been added to the report to support Kewaunees conversion to Improved Technical Specifications (ITS).
- 1. Page 3 - Added Kewaunees Setpoint Control Program to Section 1.1, Purpose.
- 2. Page 3 - Added Kewaunee LCOs 3.3.1, 3.3.2, 3.3.5, 3.3.6, and 3.3.7 to Section 1.2, Scope.
- 3. Page 4 - Added and updated definitions in Section 2.1 to reflect Kewaunees Setpoint Control Program and the adoption of TSTF-493, Rev. 4, Option B.
- 4. Page 5 - Added and updated definitions in Section 2.1 to reflect Kewaunees Setpoint Control Program and the requirements from TSTF-493, Rev. 4 and RIS 2006-17.
- 5. Page 9 - Updated Section 2.2.2 to reflect current conditions for North Anna and Surry. Also, a discussion for Kewaunee was added to address the Setpoint Control Program.
- 6. Page 10 - Added a discussion in Sections 2.2.2 and 2.2.3 pertaining to the issuance of RIS 2006-17.
- 7. Page 11 - Added a discussion in Section 2.2.4 pertaining to the issuance of TSTF-493, Rev. 4.
- 8. Pages 12 and 13 - Added Section 2.2.6 to address Kewaunees adoption of TSTF-493, Rev. 4, Option B.
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EE-0116 Revision 7
- 9. Page 14 - Added Kewaunee to the discussion in Sections 3.1 and 3.2.
- 10. Page 15 - Updated information to reflect current conditions for North Anna and Surry and to add Kewaunees Setpoint Control Program nomenclature.
- 11. Page 18 - Updated information to reflect current conditions for Surry.
- 12. Page 19 - Added discussion for Kewaunees Protection and Control System.
- 13. Page 20 - Continued discussion of Kewaunees Protection and Control System and updated information to reflect current conditions for North Anna.
- 14. Pages 21, 22, and 23 - Revised the Multiple Parameter Protection Functions discussion to evaluate Kewaunees OTT instead of Surrys.
- 15. Page 24 - Added Kewaunee in the Notes section where applicable.
- 16. Pages 39 Through 45 - Added Section 3.5 to describe Kewaunees Setpoint Methodology.
- 17. Page 65 - Revised wording of the Allowable Value for North Annas Steam Flow Feed Flow Mismatch Reactor Trip.
- 18. Pages 74 through 76 - Revised North Annas High Steam Flow ESFAS analysis to reflect the results of Calculation EE-0736, Rev. 5 and to reflect conditions at 20 % power.
- 19. Page 91 and 92 - Added the analysis for North Annas RWST Low Level ESFAS function based on DCP 59-DCP-06-013 and DCP 59-DCP-06-015.
- 20. Pages 104 through 107 - Corrected error in Surrys OTT analysis. There is no change to the current LSSS and there is still positive margin to the Safety Analysis Limit for the three conditions analyzed.
- 21. Page 118 - Corrected error in the description of the operation of P-7 and P-10.
- 22. Page 129 and 130 - Updated Surrys High Steam Flow ESFAS analysis based on unit specific PREF values and to reflect conditions at 20 % power.
- 23. Pages 143 through 169 - Added Section 4.5 to perform the setpoint analysis for Kewaunees Reactor Protection System (LCO 3.3.1) to support the Setpoint Control Program.
- 24. Pages 170 through 185 - Added Section 4.6 to perform the setpoint analysis for Kewaunees Engineered Safety Features Actuation System (LCO 3.3.2) to support the Setpoint Control Program.
- 25. Pages 186 through 190 - Added Section 4.7 to perform the setpoint analysis for Kewaunees Loss of Offsite Power (LOOP) Diesel Generator (DG) Start Instrumentation (LCO 3.3.5),
Containment Purge and Vent Isolation Instrumentation (LCO 3.3.6), and Control Room Post Accident Recirculation (CRPAR) Actuation Instrumentation (LCO 3.3.7) to support the Setpoint Control Program.
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EE-0116 Revision 7
- 26. Pages 191 through 199 - Updated references for North Anna and Surry and added references for Kewaunee to support the analyses performed in Sections 4.5 through 4.7.
Rev. 6 1. General Change - Deleted Reference 5.2 from all analyzed RPS/RTS and ESFAS functions for North Anna and Surry in Sections 4.1 through 4.4.
- 2. Updated Section 4.3.7 to note that the Pressurizer Low Pressure Reactor Trip Allowable Value and Nominal Trip Setpoint was changed based on Reference 5.139.
- 3. Updated Section 4.3.18 to note that the Permissive P-7, Block Low Power Trips Allowable Value and Nominal Trip Setpoint was changed based on Reference 5.139.
- 4. Updated Section 4.4.4 to note that the Pressurizer Pressure Low-Low ESFAS Function Allowable Value and Nominal Trip Setpoint was changed based on Reference 5.139.
- 5. Revised Section 4.5.3 to change the analysis for the Power Range Neutron Flux High Positive Rate Reactor Trip to allow the currently installed Nominal Trip Setpoint and Rate Lag Derivative Time Constant to remain in place for the ITS conversion.
- 6. Revised Section 4.5.4 to change the analysis for the Power Range Neutron Flux High Negative Rate Reactor Trip to allow the currently installed Nominal Trip Setpoint and Rate Lag Derivative Time Constant to remain in place for the ITS conversion.
- 7. Revised Section 4.5.6 to base the Source Range Neutron Flux High Reactor Trip analysis on a process range of 0 to 5.301 Decades versus 0 to 6 Decades.
- 8. Revised Section 4.6.6 High Steam Flow Coincident with Safety Injection and Coincident with TAVG Low-Low to allow the Nominal Trip Set point to be changed from 0.494
- 106 lbs/hr to 0.75
- 106 lbs/hr.
- 9. Added Section 4.7.7 to address the inclusion of the Turbine Building Service Water Header Isolation Function in ITS Table 3.3.2-1.
- 10. Added References 5.136 through 5.142 to support the some of the changes described above.
Rev. 7 1. Changed the title in Sections 4.5.15 and 4.6.10 to Steam Generator Low Low Level Reactor Trip / Auxiliary Feedwater Initiation.
- 2. Added Section 4.5.18 to address the inclusion of the Turbine Trip Low Fluid Oil Pressure function in ITS Table 3.3.1-1.
- 3. Re-numbered Sections 4.5.18 through 4.5.23.
- 4. Added Reference 5.144 to support the changes associated with Section 4.5.18.
vi
EE-0116 Page 1 of 205 Revision 7 TABLE OF CONTENTS SECTION PAGE
1.0 INTRODUCTION
3 1.1 Purpose 3 1.2 Scope 3 2.0 OVERVIEW 4 2.1 Definitions 4 2.2 The Significance of the Allowable Value 8 2.2.1 Background 8 2.2.2 Addressing Recent NRC Concerns Associated With Allowable Values 8 2.2.3 The NRC Staff Position Concerning the LSSS and AV 10 2.2.4 The ISA/ NEI/Various Industry Groups Position Concerning the LSSS and AV 10 2.2.5 The Dominion Position Concerning the LSSS and AV for North Anna and Surry 11 2.2.6 The Dominion Position Concerning the LSSS and AV for Kewaunee 12 3.0 METHODOLOGY 14 3.1 Introduction 14 3.2 Functional Groups for RPS(RTS) and ESFAS Instrumentation 14 3.3 The Instrumentation, Systems and Automation Society (ISA) Methodologies Used to Calculate Allowable Values 24 3.3.1 Method 1 25 3.3.2 Method 2 26 3.3.3 Method 3 26 3.3.4 Method 3 with Additional Margin 27 3.4 Methodology for Determining North Anna Allowable Values and Surry LSSS/Setting Limits 29 3.4.1 Primary RTS and ESFAS Trips and Permissives Credited in the Safety Analysis 29 3.4.2 Backup RTS and ESFAS Trips and Permissives Not Credited in the Safety Analysis 30 3.4.3 Calculating Actual Allowable Values for North Anna and LSSS/Setting Limits for Surry 31 3.5 Methodology for Determining Kewaunees Allowable Value and Limiting Trip 39 Setpoint Based on TSTF-493 and RIS 2006-17 3.5.1 Primary RPS and ESFAS Trips, Permissives, and Other LCOs Credited in the 39 Kewaunee Safety Analysis 3.5.2 Backup RPS and ESFAS Trips, Permissives and Other LCOs Not Credited in the 41 Kewaunee Safety Analysis 3.5.3 Calculating Limiting Trip Setpoints, Allowable Values, and As Found 42 Tolerances for Kewaunee Power Station
EE-0116 Page 2 of 205 Revision 7 TABLE OF CONTENTS (CONTINUED)
SECTION PAGE 4.0 RESULTS 46 4.1 Allowable Values for North Anna ITS Table 3.3.1-1 (RTS Instrumentation) 46 4.2 Allowable Values for North Anna ITS Table 3.3.2-1 (ESFAS Instrumentation) 69 4.3 Limiting Safety System Settings (LSSS) for Surry Power Station Custom Technical 95 Specifications, Section 2.3, Limiting Safety System Settings, Protective Instrumentation and Protective Instrumentation Settings for Reactor Trip Interlocks.
4.4 Setting Limits for Surry Power Station Custom Technical Specifications, Table 3.7-4, 122 Engineered Safety Features Actuation System Instrumentation Setting Limits and Table 3.7-2, Engineered Safety Features Actuation System Instrumentation Operating Conditions 4.5 Limiting Trip Setpoints, Allowable Values, As Found Tolerances, and As Left Tolerances for 143 Kewaunee Reactor Protection System (RPS) Instrumentation to Support the Setpoint Control Program 4.6 Limiting Trip Setpoints, Allowable Values, As Found Tolerances, and As Left Tolerances for 174 Kewaunee Engineered Safety Features Actuation System (ESFAS) Instrumentation to Support Setpoint Control Program 4.7 Limiting Trip Setpoints, Allowable Values, As Found Tolerances, and As Left Tolerances for 190 Kewaunee Instrumentation Associated with LCOs 3.3.5, 3.3.6, and 3.3.7 to Support the Setpoint Control Program
5.0 REFERENCES
196
EE-0116 Page 3 of 205 Revision 7
1.0 INTRODUCTION
1.1 Purpose The purpose of this document is to provide a comprehensive and controlled reference which details the design basis for the Allowable Values that appear in North Anna Power Station Improved Technical Specifications (ITS), Kewaunee Power Station Setpoint Control Program, and the LSSS/Setting Limit Values that appear in Surry Power Station Custom Technical Specifications (CTS).
1.2 Scope
- This document provides the basis for the Allowable Values to be used in North Anna Power Station Improved Technical Specifications, Table 3.3.1-1, Reactor Trip System Instrumentation (NAPS).
- This document provides the basis for the Allowable Values to be used in North Anna Power Station Improved Technical Specifications, Table 3.3.2-1, Engineered Safety Feature Actuation System Instrumentation (NAPS).
- This document provides the basis for the Limiting Safety System Settings (LSSS) to be used in Surry Power Station Custom Technical Specifications, Section 2.3, Limiting Safety System Settings, Protective Instrumentation.
- This document provides the basis for the Setting Limit Values to be used in Surry Power Station Custom Technical Specifications, Table 3.7-4, Engineered Safety Feature System Initiation Limits Instrument Setting and Table 3.7-2, Engineered Safeguards Action Instrument Operating Conditions.
- This document provides the basis for the Reactor Protection System (RPS) Instrumentation (LCO 3.3.1)
Limiting Trip Setpoints, Nominal Trip Setpoints, Allowable Values, As Found Tolerances, and As Left Tolerances to be used in Kewaunee Power Stations Setpoint Control Program to support the conversion to Improved Technical Specifications.
- This document provides the basis for the Engineered Safety Features Actuation System (ESFAS)
Instrumentation Functions (LCO 3.3.2) Limiting Trip Setpoints, Nominal Trip Setpoints, Allowable Values, As Found Tolerances, and As Left Tolerances to be used in Kewaunee Power Stations Setpoint Control Program to support the conversion to Improved Technical Specifications.
- This document provides the basis for the Loss of Offsite Power (LOOP) Diesel Generator (DG) Start Instrumentation (LCO 3.3.5) Limiting Trip Setpoints, Nominal Trip Setpoints, Allowable Values, As Found Tolerances, and As Left Tolerances to be used in Kewaunee Power Stations Setpoint Control Program to support the conversion to Improved Technical Specifications.
- This document provides the basis for the Containment Purge and Vent Isolation Instrumentation (LCO 3.3.6) and the Control Room Post Accident Recirculation (CRPAR) Actuation Instrumentation (LCO 3.3.7) As Found and As Left Tolerances to be used in Kewaunee Power Stations Setpoint Control Program to support the conversion to Improved Technical Specifications.
EE-0116 Page 4 of 205 Revision 7 2.0 OVERVIEW 2.1 Definitions Accuracy - A degree of conformity of an indicated value to a recognized, accepted standard value or ideal value.
Allowable Value (AV) - is the threshold value used to determine channel operability during the performance of channel functional tests and channel calibrations. The AV is the limiting as found setting for the channel trip setpoint that accounts for all of the NON-COT error components from the CSA Calculation in accordance with Methods 1 or 2 from ISA-RP67.04.02-2000 and ISA-RP67.04-Part II-1994.
Analytical Limit (AL) - The setpoint value assumed in the Safety Analysis. In the context of this document, the Analytical Limit is the same as the Safety Analysis Limit (SAL).
As Found Tolerance (AFT) - For Surry and North Anna, the As Found Tolerance is equal to the Allowable Value or Limiting Safety System Setting (LSSS)/Setting Limit listed in Technical Specifications. For Kewaunee, the As Found Tolerance is equal to the statistical combination of the rack error components and rack drift.
As Left Tolerance (ALT) - is not applicable for Surry and North Anna. For Kewaunee the As Left Tolerance is equal to the statistical combination of the rack error components minus the rack drift.
Calibrated Range - The calibration span of the sensor/transmitter as it applies to the indicated process range of the loop/system.
Channel Statistical Allowance (CSA) - The total instrument loop uncertainty (usually expressed in percent of instrument span) where non-interactive error components are combined statistically and interactive error components are summed arithmetically in accordance with Dominion Standard STD-EEN-0304 (Ref. 5.5).
The generic CSA equation and a summary of error terms are provided below in Table 2.1.
Channel Operational Test (COT) - A COT shall be the injection of a simulated or actual signal into the channel as close to the sensor as practicable to verify OPERABILITY of all devices in the channel required for channel OPERABILITY. The COT shall include adjustments, as necessary, of the required alarm, interlock, and trip setpoints required for channel OPERABILITY such that the setpoints are within the necessary range and accuracy. The COT may be performed by means of any series of sequential, overlapping, or total channel steps. In the context of this document, the Channel Operational Test is the same as a Channel Periodic Test or Channel Functional Test.
Instrument Loop - An arrangement or chain of modules or components as required to generate one or more protective/control signals and/or provide indication and recording functions. An Instrument Loop normally includes the following five elements; the process, a transmitter/sensor, process electronics, indications and/or automatic control elements.
EE-0116 Page 5 of 205 Revision 7 Limiting Safety System Setting (LSSS) - The LSSS is a term used in the Surry Power Station CTS to define the threshold value used to determine channel operability during the performance of channel functional tests and channel calibrations. In the context of this document, the CTS LSSS or Setting Limit used for Surry Power Station is equivalent to the ITS Allowable Value used for North Anna Power Station and the As Found Tolerance for Kewaunee.
Limiting Trip Setpoint (LTSP) - Based on RIS 2006-17 and TSTF-493, Rev. 4, the LTSP is the limiting setting for the channel trip setpoint considering all credible instrument errors associated with the instrument channel (Refs. 5.99 and 5.100).
Margin - The resultant value when the Channel Statistical Allowance (CSA) value is subtracted from the Total Allowance Value (usually expressed in percent of span or the process/signal values corresponding to these).
Module - A generic term for a Westinghouse Nuclear Instrumentation Module, Westinghouse 7300 Series PC Card, Foxboro Module, NUS Module, or a Westinghouse/Hagan 7100 Electronic Module.
Nominal Trip Setpoint (NTSP) - The desired setpoint for the variable. Initial calibration and subsequent re-calibrations should be made at the Nominal Trip Setpoint value specified in approved plant documentation.
According to RIS 2006-17 and TSTF-493, Rev. 4 (Refs. 5.99 and 5.100), the NTSP is the Limiting Trip Setpoint with margin added. The NTSP is always equal to or more conservative than the LTSP.
Operating Margin - The difference between the nominal operating value for the process parameter and the most limiting trip/alarm setpoint/control limit (usually expressed in percent of span or the process/signal values corresponding to these).
Process Range - The upper and lower limits of the operating region for a device, e.g., for a Pressurizer Pressure Transmitter, 0 to 3000 PSIG, for Steam Generator Level, 0 to 100 % Level. This is not necessarily the calibrated range of the device, e.g., for the Pressurizer Pressure Transmitter, the typical calibrated range is 1700 to 2500 PSIG.
Rack Error Components - These are the error terms associated with the process modules that are used to develop a Channel Statistical Allowance (CSA) value for a particular trip/alarm function. These rack error components are the calibration tolerances associated with the process modules for a module calibration (M1, M2 ... Mn) or (RCA & RCSA) for string calibration and an uncertainty value to account for Rack Drift (RD). These rack error components are combined statistically to determine the maximum allowable error which, ideally, should be used to determine the Allowable Value/LSSS/Setting Limit.
Safety Analysis Limit (SAL) - The setpoint value assumed in the Safety Analysis. In the context of this document, the Safety Analysis Limit is equivalent to the Analytical Limit (AL).
Span - The difference between the upper and lower range values of a process parameter or the signal values corresponding to these.
Tolerance - The allowable deviation from an ideal calculated value.
EE-0116 Page 6 of 205 Revision 7 Total Allowance - The difference between the Nominal Trip Setpoint and the Safety Analysis Limit (usually expressed in percent of span or the process/signal values corresponding to these).
Total Loop Uncertainty (TLU) - In the context of this document, the TLU is equivalent to the Channel Statistical Allowance (CSA). A summary of TLU/CSA error terms is provided in Table 2.1 below.
EE-0116 Page 7 of 205 Revision 7 Table 2.1: Channel Statistical Allowance (CSA) Equation and Error Term Definitions CSA = SE + [EA2 + PMA2 + PEA2 + (SCA+SMTE)2 + SD2 + SPE2 + STE2 + SPSE2 + (M1+M1MTE)2 +
(M2+M2MTE)2 + + (Mn+MnMTE)2 + RD2 + RTE2 + RRA2]1/2 Systematic Error (SE) Systematic Error is treated as a bias (unidirectional) and is always placed outside (NON-COT) of the radical. Examples of Systematic Error are transmitter reference leg heatup, uncorrected Sensor Pressure Effects (SPE) and the SG Mid Deck Plate bias.
Environmental Allowance (EA) Environmental Allowance is normally associated with instrument loop sensors and (NON-COT) equipment that is subjected to a HARSH environment during DBE and/or PDBE conditions. EA is made up of Insulation Resistance (IR) Effects, Radiation Effects (RE), Steam Pressure Temperature Effects (SPTE) and Seismic Mounting Effects (SME).
Process Measurement Accuracy (PMA) Process Measurement Accuracy is an allowance for non-instrument related effects (NON-COT) that directly influence the accuracy of the instrument loop. Examples of PMA are fluid stratification effects on temperature measurement and the effects of fluid density changes on level measurement.
Primary Element Accuracy (PEA) Primary Element Accuracy is an allowance for the inaccuracies of the system (NON-COT) element that quantitatively converts the measured variable energy into a form suitable for measurement.
Sensor Calibration Accuracy (SCA) Sensor Calibration Accuracy is a number or quantity that defines a limit that errors (NON-COT) will not exceed when a sensor is used under specified operating conditions, i.e.,
the calibration accuracy of the sensor.
Sensor Measuring & Test Equipment (SMTE) Sensor Measuring & Test Equipment is associated with the accuracy of the (NON-COT) Measuring and Test Equipment (M&TE) used to calibrate the loop sensor(s).
Examples of SMTE are Test Gauges and Digital Multimeters (DMM).
Sensor Drift (SD) Sensor Drift is an allowance for the change in the input versus output relationship (NON-COT) of the sensor over a period of time under specified reference operating conditions.
Sensor Pressure Effects (SPE) Sensor Pressure Effects are allowances for the steady-state pressure applied to a (NON-COT) device. Normally, SPE applies only for differential pressure devices and is associated with the change in input-output relationship due to a change in static pressure. SPE is divided into two terms, Static Pressure Zero Effect (SPZE) and Static Pressure Span Effect (SPSE).
Sensor Temperature Effects (STE) Sensor Temperature Effect is an allowance for the effects of changes in the (NON-COT) ambient temperature surrounding the sensor.
Sensor Power Supply Effect (SPSE) Sensor Power Supply Effect is an allowance for the effects of changes in the (NON-COT) power supply voltage applied to the sensor.
Module Calibration Accuracy (M1 through Mn) Module M1 to Mn is an Allowance for the accuracy of an assembly of (COT) interconnected components that constitute an identifiable device, instrument, or piece of equipment. A module can be disconnected, removed as a unit and replaced with a spare. It has definable performance characteristics that permit it to be tested as a unit.
Module Measuring & Test Equipment (MnMTE) Module Measuring & Test Equipment is associated with the accuracy of the (NON-COT) Measuring and Test Equipment (M&TE) used to calibrate the loop module(s).
Examples of MnMTE are Decade Boxes, Digital Multimeters (DMM), Test Point Resistors (TPR), Oscilloscopes and Recorders.
Rack Drift (RD) Rack Drift is an allowance for the change in the input versus output relationship of (COT) the Rack Modules (M1 through Mn) over a period of time under specified reference operating conditions.
Rack Temperature Effect (RTE) Sensor Temperature Effect is an allowance for the effects of changes in the (NON-COT) ambient temperature surrounding the Process Racks.
Rack Readability Allowance (RRA) Rack Readability Allowance is an allowance for the inability to read analog (N/A) indicators because of parallax distortion.
EE-0116 Page 8 of 205 Revision 7 2.2 The Significance of the Allowable Value 2.2.1 Background Historically, for plants that have used Westinghouse Standardized Technical Specifications (STS) such as North Anna, two values have been provided for each Reactor Trip System (RTS) and Engineered Safety Features Actuation System (ESFAS) trip function; they are referred to as the "Nominal Trip Setpoint" and the "Allowable Value" (in the context of this document, the Allowable Value, Limiting Safety System Setting LSSS and the Setting Limit are the same). The difference in percent of span between the Nominal Trip Setpoint and the Allowable Value was calculated, in most cases, based on a summation of the errors associated with the rack components and rack drift. For linear, non-complex trip functions, this value normally worked out to be between 1.0 % and 2.0 % of span. For complex trip functions or functions that had limited margin with respect to the Safety Analysis Limit, other calculational methods were used to determine the difference between the Nominal Trip Setpoint and the Allowable Value. For plants that do not use the Westinghouse STS version of Technical Specifications such as Surry, normally only one setpoint value (assumed to be the Limiting Safety System Setting LSSS or the Setting Limit at Surry) is provided in the text with no guidance as to how to set the actual "Nominal" Trip Setpoint in the plant.
Based on the early versions of the Westinghouse STS, the original definition of the LSSS (i.e., the Allowable Value) was stated as follows:
"A setting chosen to prevent exceeding a Safety Analysis Limit".
This Allowable Value was intended to be used during monthly or quarterly Functional Testing as a "flag" such that if a bistable (comparator) Trip Setpoint exceeded this value, the protection channel would be declared inoperable and plant staff would be required to initiate corrective action. The intended significance of this value is that it is the point where if the value is exceeded, the implication is that the actual rack electronics and/or associated rack error components have exceeded the values assumed in the Channel Statistical Allowance (CSA) Calculation and consequently, the margin with respect to the Safety Analysis Limit has been reduced.
The Allowable Value takes on added significance when there is little or no retained/available margin with respect to the Safety Analysis Limit and conversely takes on reduced significance in proportion to the amount of retained/available margin.
2.2.2 Addressing Recent NRC Concerns Associated with Allowable Values Dominion Corporate I&C Engineering attended a meeting with the Nuclear Regulatory Commission (NRC) and Nuclear Energy Institute (NEI) in Rockville, MD on October 8, 2003 to evaluate NRC concerns associated with the Allowable Values used in Technical Specifications. The Allowable Values of interest are those associated with Reactor Protection System (RPS) (e.g., also known as the Reactor Trip System RTS) and Engineered Safety Features Actuation System (ESFAS) Functions that are credited in the Plant Specific Safety Analysis. The NRC expressed a basic concern at the meeting where they have identified various plants that use a method to calculate Allowable Values for RTS and ESFAS functions that will reduce or eliminate margin to the Analytical Limit (AL), i.e., also known as the Safety Analysis
EE-0116 Page 9 of 205 Revision 7 Limit (SAL). In the worst case scenario, the margin may be determined to be negative such that the protection function is operating outside of the analyzed region.
On August 13, 2003, NRC Staff met with members of the ISA 67.04 committee and other industry groups in Rockville, MD to discuss instrument setpoint methodology and lay out their position. The major area of discussion focused on the instrument setpoint methodology recommended in ISA Standard S67.04 used by many licensees for determining protection system instrumentation setpoints. Part II of the standard, not endorsed by the NRC Staff, includes three methods for calculating Allowable Values which represent the Limiting Safety System Settings (LSSS) as described in 10CFR50.36. As stated by the NRC, Methods 1 and 2 determine Allowable Values that are sufficiently conservative and are acceptable to the NRC Staff.
According to the NRC, Method 3 does not appear to provide an acceptable degree of conservatism and is of concern to the NRC Staff. In addition, there is also a disagreement between the NRC Staff and NEI/ISA/Some Industry Groups as to the meaning/intent of the LSSS. These items will be addressed in this document as they apply to Surry and North Anna.
As of August 2002 North Anna adopted Improved Technical Specifications (ITS). Within the North Anna ITS and ITS Bases, Allowable Values are explicitly defined and are uniquely associated with each RTS and ESFAS function, to include Backup Trips and Permissives. The Allowable Values specified in North Annas ITS as described in this Technical Report are based on Methods 1 or 2 from ISA-RP67.04.02-2000 and ISA-RP67.04-Part II-1994.
Surry Power Station has not adopted ITS and has decided to continue using their Custom Technical Specifications (CTS). For plants licensed before 1974, prior to the introduction of Standardized Technical Specifications (STS), the setpoints (i.e., Technical Specification Limits) included in CTS for RPS and ESFAS instrumentation were based on the plant specific setpoint study and/or based on settings provided in the Westinghouse Precautions, Limitations and Setpoints (PLS) document. The RPS and ESFAS trip setpoints specified in CTS did not include allowances for instrument uncertainties associated with channel functional testing (i.e., the COT). These allowances were left up to the licensee to deal with and justify. At the present time, this applies to Surry. In many cases, the original CTS setpoints for RPS and ESFAS instrumentation have been determined to be unacceptable based on todays standards and setpoint methodologies. To address this discrepancy, Technical Specification Change Request (TSCR) No. 318 was prepared to revise 16 Limiting Safety System Settings for the Reactor Protection System and 11 Setting Limits for the Engineered Safety Features Actuation System. The revised Limiting Safety System Settings and Setting Limits were calculated in accordance with Methods 1 or 2 from ISA-RP67.04.02-2000 and ISA-RP67.04-Part II-1994. TSCR No. 318 was approved by the USNRC via Surry Technical Specifications Amendments 261/261 dated September 23, 2008 (Serial # 080594). The revised Limiting Safety System Settings, Setting Limits, and four setpoint changes were implemented for Surry Units 1 and 2 in November of 2008.
At the present time, Kewaunee Power Station is also using Custom Technical Specifications (CTS).
Kewaunees CTS is very similar to the CTS used at Surry Power Station. Dominion has decided that Kewaunee will convert to Improved Technical Specifications (ITS) in the near future. As part of the ITS conversion, Kewaunee will remove their Reactor Protection System LSSSs, ESFAS Setting Limits (known as Allowable Values in ITS), Diesel Generator (LOOP), Containment Purge and Vent Isolation, and Control Room Post Accident Recirculation Actuation from Technical Specifications and maintain control of these and other critical limits in a Setpoint Control Program as allowed by Option B of TSTF-493,
EE-0116 Page 10 of 205 Revision 7 Revision 4 (Ref. 5.99). The Setpoint Control Program will be administered as defined in ITS, Section 5.5.16 Setpoint Control Program. Like North Anna and Surry, the Allowable Values for RPS and ESFAS Instrumentation, as administered by the Setpoint Control Program will be calculated in accordance with Methods 1 or 2 from ISA-RP67.04.02-2000 and ISA-RP67.04-Part II-1994. The Kewaunee Diesel Generator (LOOP), Containment Purge and Vent Isolation, and Control Room Post Accident Recirculation Actuation instrumentation will be handled using Methods 1 and 2 as applicable.
The following subsections will focus on the meaning/intent of the Limiting Safety System Setting (LSSS) and the Allowable Value (AV) as understood by the NRC, ISA/NEI/Various Industry Groups and Dominion.
2.2.3 The NRC Staff Position Concerning the LSSS and AV The following LSSS information is based on information from the NRC presentation to the ISA 67.04 Committee on August 13, 2003.
10CFR50.36(C)(1)(ii)(A) defines the Limiting Safety System Setting (LSSS) as the setting that must be chosen so that the automatic protective action will correct the abnormal situation before a safety limit is exceeded.
New Improved TS Bases defines allowable value (AV) to be equivalent to LSSS and defines that a channel is operable if the trip setpoint is found not to exceed the AV during the Channel Operational Test (COT).
Prior to the issuance of NRC Regulatory Issue Summary (RIS) 2006-17, the NRC Staff believed that the Allowable Value (AV) is equivalent to the Limiting Safety System Setting (LSSS). Since the issuance of RIS 2006-17 (Ref. 5.100), the NRCs staff position is that the Limiting Trip Setpoint (LSP) protects the Safety Limit (SL) and relationship between the Allowable Value and the LSSS has been expanded upon as discussed in Section 2.2.6.(1) 2.2.4 The ISA/NEI/Various Industry Groups Position Concerning the LSSS and AV The following information is based on the ISA 67.04 Subcommittee handout from August 13, 2003.
Position Statements
- The difference between the Allowable Value (AV) and the Analytical Limit (AL) is not a direct defense of the AL.
(1) There is a difference in the terminology and abbreviations used in TSTF-493, Rev. 4 versus RIS 2006-17 with respect to the Limiting Trip Setpoint and the Safety Limit.
EE-0116 Page 11 of 205 Revision 7 Summary
- Reg Guide 1.105 endorses the calculation of the TSP using statistical methods.
- The AV validates an error contribution assumption via periodic surveillance testing.
- The errors between the AV and the AL are not part of the LSSS as defined by 10CFR50.36.
In summary, ISA/NEI/Various Industry Groups believe that the Allowable Value (AV) is equivalent to the Limiting Safety System Setting (LSSS). However, their position is that the TSP is used to protect the Analytical Limit (AL). All of the items listed above are true, with the exception of The TSP protects the AL. This is the statement that is under dispute.
Since August of 2003, the Industry has been developing Technical Specification Task Force Improved Standard Technical Specifications Change Traveler TSTF-493. This document addresses the agreement made between the USNRC and the industry concerning the issues listed above. Dominions implementation of the requirements set forth in TSTF-493, Revision 4 (Ref. 5.99) as they apply to Kewaunee Power Station will be addressed in Sections 2.2.6 and 3.5.
2.2.5 The Dominion Position Concerning the LSSS and AV for North Anna and Surry The following definition of the Allowable Value is taken from North Anna Power Station ITS Bases, Page B.3.3.1-2, Revision 0.
Use of the Trip Setpoint to define as found OPERABILITY and its designation as the LSSS under the expected circumstances described above would result in actions required by both the rule and technical specifications that are clearly not warranted. However, there is also some point beyond which the device would have not been able to perform its function due, for example, to greater than expected drift.
This value needs to be specified in the technical specifications in order to define OPERABILITY of the devices and is designated as the Allowable Value which, as stated above, is the same as the LSSS.
The following definition of the Allowable Value is taken from the North Anna ITS Bases, Page B.3.3.1-3, Revision 0.
The Allowable Value specified in Table 3.3.1-1 serves as the LSSS such that a channel is OPERABLE if the trip setpoint is found not to exceed the Allowable Value during the CHANNEL OPERATIONAL TEST (COT). As such, the Allowable Value differs from the Trip Setpoint by an amount primarily equal to the expected instrument loop uncertainties, such as drift, during the surveillance interval. In this manner, the actual setting of the device will still meet the LSSS definition and ensure that a Safety Limit is not exceeded at any given point of time as long as the device has not drifted beyond that expected during the surveillance interval. If the actual setting of the device is found to have exceeded the Allowable Value the device would be considered inoperable for a technical specification perspective.
This requires corrective action including those actions required by 10CFR50.36 when automatic protective devices do not function as required. Note that, although the channel is OPERABLE under
EE-0116 Page 12 of 205 Revision 7 these circumstances, the trip setpoint should be left adjusted to a value within the established trip setpoint calibration tolerance band, in accordance with uncertainty assumptions stated in the referenced setpoint methodology (as-left criteria), and confirmed to be operating within the statistical allowances of the uncertainty terms assigned.
As can be seen, the ITS Bases definition of the LSSS and the AV is consistent with the NRC Staff position. Because the AV is the only value provided in ITS and thus the Operating License, it is the only value the NRC has available to use when evaluating plant submittals. It is also the only value that we use to determine the OPERABILITY of RTS and ESFAS channels during the COT. Therefore, it is Dominions position that the Analytical Limit will be protected if:
- 1. the distance between the Trip Setpoint and the Analytical Limit is equal to or greater than the Total Loop Uncertainty for that channel and
- 2. the distance between the Allowable Value and the Analytical Limit is equal to or greater than the NON-COT error components of the Total Loop Uncertainty and
- 3. the distance between the Trip Setpoint and the Allowable Value is equal to the COT error components of the Total Loop Uncertainty. The Allowable Value for certain functions may be rounded to a whole number that remains bounded by the available Safety Margin.
Both the Trip Setpoint and the Allowable Value must be properly established in order to adequately protect the Analytical Limit.
2.2.6 The Dominion Position Concerning the LSSS and AV for Kewaunee Dominion has decided to adopt Improved Technical Specifications (ITS) for Kewaunee. As part of the ITS conversion, Dominion has chosen to implement Option B of TSTF-493, Revision 4 (Ref. 5.99). TSTF-493, Revision 4, Option B allows for the relocation of Reactor Protection System RPS (also known as the Reactor Trip System RTS) and Engineered Safety Features Actuation System - ESFAS (also known as Engineered Safety Features - ESF) Allowable Values (also known as the Limiting Safety System Settings - LSSSs or Setting Limits) from Section 3.3 of Technical Specifications to a Licensee controlled program as defined in ITS Section 5.5.16. In addition, the Diesel Generator (LOOP), Containment Purge and Vent Isolation, and Control Room Post Accident Recirculation Actuation instrumentation will also be relocated to the Licensee controlled program as defined in ITS Section 5.5.16. To implement TSTF-493, Option B, Dominion will incorporate the relevant positions taken by the industry as detailed in TSTF-493, Revision 4 and those taken by the USNRC as detailed in NRC Regulatory Issue Summary 2006-17, Dated September 19, 2006 (Refs. 5.99 and 5.100) into the Setpoint Control Program in accordance with ITS Section 5.5.16.
New and/or revised terminology and requirements have been incorporated into TSTF-493 and NRC Regulatory Issue Summary (RIS) 2006-17 that are to be used for the determination of RPS and ESFAS Setpoints. The new terminology and requirements detailed in TSTF-493, Revision 4 and RIS 2006-17 will be incorporated into Kewaunees Setpoint Control Program as described in ITS Section 5.5.16. In addition to the new terminology and requirements, the USNRC has taken the position that the Limiting Trip Setpoint (LTSP) protects the Safety Limit (SL) (Ref. 5.100). This revised position is a change from the historical definition of the Allowable Value as delineated in Standardized Technical Specifications
EE-0116 Page 13 of 205 Revision 7 (STS), i.e., "A setting chosen to prevent exceeding a Safety Analysis Limit" (Ref. 5.3). Since the Limiting Trip Setpoint (LTSP) accounts for all credible instrument errors associated with the instrument channel, it is a more conservative setting than the associated Allowable Value as defined in Section 3.5. With respect to Kewaunees conversion to ITS, Dominion agrees with this revised position based on explanations and guidance provided in TSTF-493, Revision 4 and RIS 2006-17.
Like North Anna and Surry, Kewaunees Setpoint Methodology is based on Methods 1 or 2 from ISA-RP67.04.02-2000 and ISA-RP67.04-Part II-1994. Using Methods 1 or 2 will ensure that the Allowable Value (equivalent to the Minimum or Maximum Allowable Value for Surry and North Anna) will account for all credible instrument and process errors that are not tested or quantified during the performance of the Channel Operational Test (COT). This Setpoint Methodology addresses the basic NRC concern brought up back in 2003 that Method 3 (used by some Licensees to determine Allowable Values) as described in ISA-RP67.04.02-2000 and ISA-RP67.04-Part II-1994 may yield Allowable Values that will not protect the Safety Limit under all postulated conditions. In addition to using Methods 1 or 2, Kewaunees Setpoint Methodology will incorporate the revised terminology and additional requirements imposed by TSTF-493, Revision 4 and RIS 2006-17. A detailed discussion of Kewaunees Setpoint Methodology incorporating the revised terminology and requirements from TSTF-493 and RIS 2006-17 is provided in Section 3.5.
EE-0116 Page 14 of 205 Revision 7 3.0 METHODOLOGY 3.1 Introduction Many Westinghouse Plants continue to use Westinghouse or other Engineering Firms to perform some or all of their Safety Analysis Functions. In addition, Westinghouse has also performed the RPS (RTS) and ESFAS Setpoint Study for many of their plants. Typically, the Setpoint Study for these plants included the development of Channel Statistical Allowance (CSA) Calculations for Primary and some of the Backup RTS and ESFAS Trip Functions. Derived from these Setpoint Studies and CSA Calculations are the Allowable Values that appear in various versions of Standardized Technical Specifications (STS). For the Westinghouse Plants that use Custom Technical Specifications (CTS), the setpoint values specified for RPS and ESFAS Trip Functions are not defined as Allowable Values and typically, they are the same setpoint values as those found in the original Precautions, Limitations and Setpoints (PLS) Document for that particular plant. This was the case for Surrys Custom Technical Specifications until the implementation of Technical Specifications Change Request No. 318 ultimately resulting in TS Amendments 261/261 for Units 1 and 2, respectively (Ref. 5.119).
Dominion is unique in the fact that a majority of the UFSAR Chapter 14 (Surry and Kewaunee) and Chapter 15 (North Anna) Safety Analysis is performed in house by the Corporate Nuclear Analysis & Fuels Department. In addition, Channel Statistical Allowance Calculations for Primary and Backup RPS (RTS) and ESFAS Trip Functions are performed in house by the Corporate Electrical/I&C/Computers Department. Because Dominion performs their own Safety Analysis and CSA Calculations, the methodology used to determine Improved Technical Specifications (NUREG-1431 ITS) Allowable Values for North Anna, As Found Tolerances for Kewaunee, and LSSS/Setting Limits for Surry Custom Technical Specifications will be similar and in some cases more conservative than that used by Westinghouse in the past to determine Allowable Values for later versions of Standardized Technical Specifications. In addition, the methods used in this Technical Report to calculate the limiting values for North Anna, Kewaunee, and Surry will be consistent with the requirements of Methods 1 or 2 as described in ISA-RP67.04.02-2000 (Ref 5.43).
3.2 Functional Groups for RPS (RTS) and ESFAS Instrumentation.
Based on Dominion Technical Report NE-0994 (Ref. 5.1), the Reactor Protection System (RPS)/Reactor Trip System (RTS) and the Engineered Safety Features Actuation System (ESFAS) Instrumentation at North Anna, Kewaunee, and Surry can be divided into two major categories, i.e., Primary Trip Functions and Backup Trip Functions. Primary Trip Functions are credited in the Plant Safety Analysis and have an associated Analytical Limit (i.e., Safety Analysis Limit or Safety Limit). Backup Trip Functions are not credited in the Plant Safety Analysis but are included in the Reactor Protection System and the Engineered Safety Features Actuation System to enhance the overall effectiveness of the system.
Primary Trip Functions include the following:
- Primary Reactor Trip Functions
- Primary Reactor Trip Permissives
- Primary ESFAS Actuation Functions
- Primary ESFAS Permissives
EE-0116 Page 15 of 205 Revision 7 Backup Trip Functions include the following:
- Backup Reactor Trip Functions
- Backup Reactor Trip Permissives
- Backup ESFAS Permissives In addition to the above, there are three basic functional groups of Westinghouse Nuclear Instrumentation System (NIS), Foxboro H-Line, NUS Replacement Modules, Westinghouse/Hagan 7100, and Westinghouse 7300 Instrumentation that develop the majority of the RPS/RTS and ESFAS trips. These basic functional groups are divided into the three categories listed below:
- 1. Single parameter protection function
- 2. Dual parameter protection function
- 3. Multiple parameter protection function (i.e., more than two process parameters)
Different methods are used to calculate or validate the Allowable Values for North Anna, As Found Tolerances for Kewaunee, and LSSS/Setting Limits for Surry depending on whether the function is considered to be Primary or Backup. In addition, the functional group category will also effect how the Allowable Value, As Found Tolerance or LSSS/Setting Limit is calculated. Some examples of functional groups are given below.
Single Parameter Protection Functions
- Power Range Neutron Flux High and Low Reactor Trips
- Pressurizer High and Low Pressure Reactor Trips
- Low Reactor Coolant Flow Reactor Trip
- Containment Hi-1, Hi-2 and Hi-3 (North Anna only) Pressure ESFAS initiation
- Compensated Low Steam Line Pressure ESFAS initiation
- Steam Generator Lo-2 Level ESFAS initiation Dual Parameter Protection Functions
- Surry High Steam Flow in 2/3 Lines ESFAS initiation
- North Anna High P Steam Line vs. Steam Line ESFAS initiation Multiple Parameter Protection Functions
- Steam Flow Feed Flow Mismatch Reactor Trip
- Overpower T Reactor Trip
- Overtemperature T Reactor Trip
EE-0116 Page 16 of 205 Revision 7 Single Parameter Protection Functions North Anna The Nuclear Steam Supply System (NSSS) Protection and Control System at North Anna is made up of the Westinghouse Nuclear Instrumentation System (NIS) and the Westinghouse 7300 Series Process Control System. Most of the RTS and ESFAS trips generated from these systems are single parameter protection functions. Figures 3.2-1 and 3.2-2 illustrate the configuration of the Westinghouse NIS and the 7300 Process Control System.
Westinghouse Nuclear Instrumentation System - Power Range Reactor Trips NI301 QU Current Meter Amps NI303 BF 3 Detector A
% Power Meter NC306 To High Flux SSPS Upper Flux Test Switch RX Trip Trains Bistable A&B
+/- 1.0 %
+/- 1.0 %
NQ303 NM310 High Voltage Summing &
Power Supply Level Amplifier BF 3 Detector B NC305 To Test Switch Low Flux SSPS RX Trip Lower Flux Trains Bistable A&B
+/- 1.0 %
Amps Far NI302 Near Field Rack QL Current Meter Rack Field Figure 3.2-1
EE-0116 Page 17 of 205 Revision 7 Refer to Figure 3.2-1 :
CSA Calculations performed for Reactor Trips generated by NIS typically include rack error terms associated with the meter indications (i.e., Amps, % Full Power, Counts per Second, etc.) and the bistables that generate the trip.
In the case of the Power Range High Flux Reactor Trip as shown on Figure 3.2-1, the rack error terms as defined in CSA Calculation EE-0063 (Ref. 5.15) are :
(M1 + M1TE) + (M5 + M5MTE) + RD + RTE Where: M1 = Module 1 Summing and Level Amplifier = + 0.100 %
M1MTE = Module 1 Measuring and Test Equipment = + 0.110 %
M5 = Module 5 Bistable Relay Driver = + 0.833 %
M5MTE = Module 5 Measuring and Test Equipment = + 0.943 %
RD = Rack Drift = + 1.000 %
RTE = Rack Temperature Effects = + 0.500 %
Westinghouse 7300 Process Control System Low Reactor Coolant Flow Reactor Trip A B FS-414 FQ-414 FS-414-1 FC-414 Ch. Test Switch 39.9 VDC RC Flow L-NE B/S Test Switch RC Low Flow Loop Power Supply RX Trip FT-414 4 - 20 mADC (Non-Isolated) 0 - 10 VDC 24 VDC Analog Comparator Output M2 M1 TO RC Flow BS-1 TJ TP SSPS Transmitter Trains Foxboro E13DH or A& B (NCTG01) (NLPG02 or NLPG05) (NALG01) (NCTG01)
Rosemount 1153
+/- 0.75 % +/- 0.1 % +/- 0.25 %
+/- 0.25 % (MAX) Near Far Rack (MAX) Rack Field Field Figure 3.2-2 Refer to Figure 3.2-2 :
CSA Calculations performed for Reactor Trips generated by the Westinghouse 7300 Process Control System include rack error terms associated with the PC Cards that perform signal modification and the bistables that generate the trip.
In the case of the Low Reactor Coolant Flow Reactor Trip as shown on Figure 3.2-2, the rack error terms as defined in CSA Calculation EE-0060 (Ref. 5.21) are :
(M1 + M1MTE) + (M2 + M2MTE) + RD + RTE
EE-0116 Page 18 of 205 Revision 7 Where: M1 = Module 1 Loop Power Supply = + 0.100 %
M1MTE = Module 1 Measuring and Test Equipment = + 0.153 %
M2 = Module 2 Analog Comparator Bistable = + 0.250 %
M2MTE = Module 2 Measuring and Test Equipment = + 0.030 %
RD = Rack Drift = + 1.000 %
RTE = Rack Temperature Effects = + 0.500 %
These rack error terms along with other error terms from the CSA Calculation will be used to validate the existing Allowable Values at North Anna or to calculate revised Allowable Values, if necessary.
Surry The NSSS Protection and Control System at Surry uses the same Westinghouse Nuclear Instrumentation System (NIS) as North Anna. However, a majority of NSSS Protection and Control is developed from the Westinghouse/Hagan 7100 Series Process Control System (using NUS Replacement Modules for some functions). Like North Anna, most of the RPS and ESFAS trips generated from these systems are single parameter protection functions. For the Westinghouse NIS, Figure 3.2-1 is also applicable for Surry. Figure 3.2-3 illustrates the configuration of the Westinghouse/Hagan 7100 Process Control System for a single input protection function.
Westinghouse 7100 Process Control System Low Reactor Coolant Flow Reactor Trip Test Point Resistor FS-414 FC-414 A B FS-414-1 TP RC Low Flow L-NE B/S Test Switch RX Trip I/V Block FT-414 Signal Comparator 118 VAC 1 - 5 VDC Module 4 - 20 mADC RCAcompar Ch. TO RC Flow Test TJ BS-1 Transmitter Test Jack RPS Relay 131-118 or NUS Logic Rosemount 1153
+/- 0.5 % FQ-414 +/- 0.5 %
38 VDC RC Flow Loop Power Supply Module Technipower PM-38 or NUS
+/- 0.0 %
Figure 3.2-3 Refer to Figure 3.2-3 :
CSA Calculations performed for Reactor Trips generated by the Westinghouse/Hagan 7100 Process Control System also include rack error terms associated with the modules that perform signal modification and the bistables that generate the trip. The Westinghouse 7100 Process Control System mainly operates using current loops where the power supplies are not used as signal converters. In many cases, for a single parameter protection function, the only rack module that will have a tolerance
EE-0116 Page 19 of 205 Revision 7 associated with it will be the Signal Comparator (i.e., the Bistable). In the case of Surrys Low Reactor Coolant Flow Reactor Trip as shown in Figure 3.2-3, the rack error terms from CSA Calculation EE-0183 (Ref. 5.34) are :
(M5 + M5MTE) + RD + RTE Where: M5 = Rack Comparator Setting Accuracy = + 0.50 %
M5MTE = Rack Measuring and Test Equipment = + 0.15 %
RD = Rack Drift = + 1.00 %
RTE = Rack Temperature Effects = + 0.50 %
Note the difference between North Annas rack error terms compared with the rack error terms listed above for Surry. The error terms for the Loop Power Supply are not included in Surrys CSA Calculation because it is not used as a signal converter.
Kewaunee The NSSS Protection and Control System at Kewaunee uses the same Westinghouse Nuclear Instrumentation System (NIS) as does North Anna and Surry for Power Range. Most of the NSSS Protection and Control is developed from the Foxboro H-Line Process Control System (using NUS Replacement Modules for some functions). Like North Anna and Surry, most of the RPS and ESFAS trips generated from these systems are single parameter protection functions. For the Westinghouse Power Range NIS, Figure 3.2-1 is also applicable for Kewaunee. Figure 3.2-4 illustrates the configuration of the Foxboro H-Line Process Control System for a single input protection function.
Foxboro H-Line Process Control System Low Reactor Coolant Flow Reactor Trip 4872201 FQ-411 RC Flow 40 - 200 mVDC Loop Power TP/FQ-414 Supply Module
+ -
10 H/610AC-0 or NUS
+/- 0.0 %
FS-411 DB-6 4 - 20 mADC 23024 TJ FT-411 + F/411 C D
- 250 4872202 L-NE FC-411 RC Flow RC Low Flow 120 VAC Transmitter RX Trip Rosemount 1154 Channel 270 Bistable Bistable Test To RPS
+/- 0.25 % Test Switch Relay Logic H/63U-AC-OHAA or To Other Loop NUS Components +/- 0.5 %
Figure 3.2-4
EE-0116 Page 20 of 205 Revision 7 Refer to Figure 3.2-4 :
CSA Calculations performed for Reactor Trips generated by the Foxboro H-Line Control System also include rack error terms associated with the modules that perform signal modification and the bistables that generate the trip. The Foxboro H-Line Process Control System mainly operates using current loops where the power supplies are not used as signal converters. In many cases, for a single parameter protection function, the only rack module that will have a tolerance associated with it will be the Bistable Module.
In the case of Kewaunees Low Reactor Coolant Flow Reactor Trip as shown in Figure 3.2-4, the rack error terms from CSA Calculation C10819 (Ref. 5.96) are :
(M2BISTABLE + M2MTE) + RD + RTE Where: M2BISTABLE = Rack Bistable Setting Accuracy = + 0.50 %
M2MTE = Rack Measuring and Test Equipment = + 0.20 %
RD = Rack Drift = + 1.00 %
RTE = Rack Temperature Effects = + 0.50 %
Note the difference between North Annas rack error terms compared with the rack error terms listed above for Kewaunee. The error terms for the Loop Power Supply are not included in Kewaunees CSA Calculation because it is not used as a signal converter.
Dual Parameter Protection Functions Westinghouse 7300 Process Control System High Steam Flow in 2/3 Lines ESFAS - Channel 3 FQ-474 FC-474 A B FS-474 FS-474-1 Steam Flow 0 - 10 VDC High Steam Flow Ch. Test Switch 39 .9 VDC Loop Power Supply ESFAS L-NE B/S Test Switch (Non-Isolated) Analog Comparator FT-474 4 - 20 mADC 24 VDC Output M15 Steam Flow M1 BS-1 TO Transmitte r TJ TP SSPS Trains Rosemount 115 3 (NLPG0 2 or NLPG05) (NALG01) A &B (NCTG01) (NCTG01)
+/- 0 .5 % +/- 0.1 %
+/- 0.5 %
+/- 0.2 5 %
(MAX)
(MAX)
PQ-446 PS-446 PM-446B Ch. Tes t Switch Turbine Load High Stea m Flow 39.9 VDC Loop Power Supply (Non-Isolated) Setpoint Summing PT-44 6 4 - 20 mADC 0 - 10 VDC Amplifier 0 - 10 VDC Output Turbine Loa d M14 TJ TP M13 Tr ansmitter (NLPG02 or NLPG05)
Rose mount 1 153 (NSAG02)
(NCTG02) +/- 0.1 %
+/- 0.50 % +/- 0.5 %
+/- 0.25 %
(MAX)
(MAX)
Figure 3.2-5
EE-0116 Page 21 of 205 Revision 7 Figure 3.2-5 illustrates a typical dual input protection function for North Anna. Channel Statistical Allowance Calculations for dual parameter protection functions are different than single parameter functions. For example, there are more rack error terms associated with the development of the trip than a single parameter function. The rack error terms associated with North Annas High Steam Flow in 2/3 Lines ESFAS trip based on Calculation EE-0736 (Ref. 5.23) are given below :
(M1 + M1MTE) + (M13 + M13MTE) + (M14 + M14MTE) + (M15 + M15MTE) + RD + RTE Where: M1 = Steam Flow Loop Power Supply Accuracy = + 0.10 %
M1MTE = Module M1 Measuring and Test Equipment = + 0.153 %
M13 = Turbine Load Loop Power Supply Accuracy = + 0.10 %
M13MTE = Module M13 Measuring and Test Equipment = + 0.153 %
M14 = High Steam Flow Setpoint Summator Accuracy = + 0.50 %
M14MTE = Module M14 Measuring and Test Equipment = + 0.042 %
M15 = High Steam Flow Comparator Setting Accuracy = + 0.50 %
M15MTE = Module M15 Measuring and Test Equipment = + 0.042 %
RD = Rack Drift = + 1.00 %
RTE = Rack Temperature Effects = + 0.50 %
The rack error terms described in the example above along with other error terms from the CSA Calculation will be used to validate the existing Allowable Values at North Anna or to calculate revised Allowable Values, if necessary. The configuration of dual parameter protection functions at Surry is similar to North Annas. The major differences between the rack error components for both plants are based on the process control equipment as illustrated above for single input protection functions.
Multiple Parameter Protection Functions Kewaunee There are three multiple parameter protection functions at North Anna and Kewaunee, and four multiple parameter functions at Surry. Figure 3.2-6 is a block diagram that illustrates Kewaunees Overtemperature T Reactor Trip configuration (note that Overpower T and Low TAVG are also shown on the drawing). The configuration of North Annas and Surrys Overtemperature T Reactor Trip is similar, noting that the process control equipment is different.
As can be seen from Figure 3.2-6, Kewaunees Overtemperature T Reactor Trip function is derived from five process parameters, they are :
- THOT
- TCOLD
- Pressurizer Pressure
- Function of Delta Flux (FI) made up of Upper Flux (QU) and Lower Flux (QL)
EE-0116 Page 22 of 205 Revision 7 Kewaunee Power Station Overtemperature T Reactor Trip TE-401A Delta T DB Box TM -405R TT-401A DB-1 Foxboro E/E DB Box Foxboro or NUS Lead/Lag Unit DB-2 Rdf RTD R/E Converter Delta T (Delta T) Delta T Delta T (Thot) (Thot) M 1 M3 TE-401B TM -401BB DB Box TM -401-O TT-401B Foxboro E/I DB-3 Foxboro OR NUS Foxboro or NUS TAVG Lead/Lag Unit Impulse Lead/
R/E Converter Rdf RTD (TAVG) TAVG Lag Unit (TAVG)
(Tcold) M 2 TC-401A/D (Tcold) M4 M5 Foxboro or NUS Lo-Lo Stm Line Isol TAVG Bistable Stm Line M8 Isolation TM -401V TAVG Foxboro OPDT SP2 Summator Pressurizer M6 Pressure TAVG TC-401F CH. 1 Foxboro or NUS Low TAVG FRV Close FRV PT-429 PQ-429 DB Box TM -401B Bistable Closure Rosemount Foxboro or NUS DB-7 Foxboro OTDT M9 Model Pow er Supply SP1 Lead/Lag TAVG 1154SH9 M 10 PZR Unit M 7 DB Box TC-405A/B DB-4 W DAM 9000 QU OPDT OPDT Bistable RX Trip TAVG Overpow er Delta T SP NM 306 M 17 TC-405L W
Foxboro or NUS Isolation Qu > Ql Controller DB Box Amp FDQ M 13 DB-6 M 11 TM -401T Qu Foxboro Delta Q TC-405C/D Signal Selector W DAM 9000 OTDT DB Box M 15 OTDT Bistable RX Trip DB-5 Overtemperature Delta T SP QL M 18 Ql OTDT STPT NM 307 TC-401R W TM -401U Foxboro or NUS Isolation FDQ Ql > Qu Controller Foxboro Delta Q Amp M 14 Current Source M 12 M 16 Figure 3.2-6 The Overtemperature T Reactor Trip function is further broken down into channels as defined below :
- T Channel, made up of THOT and TCOLD
- TAVG Channel, made up of THOT and TCOLD
- Pressurizer Pressure Channel
- Function of Delta Flux (FI), made up of QU and QL Because there are five inputs to Kewaunees Overtemperature T function, the rack error components will be grouped as channel inputs versus a string of modules as shown above for the Dual Parameter Function example. This type of assessment will yield a conservative and valid Allowable Value (for Kewaunee, the Allowable Value will be the As Found Tolerance) using the four step method described in Sections 3.4 and 3.5 (Section 3.5 is Kewaunee specific). CSA Calculation C11865 (Ref. 5.94) was performed using a module calibration method, which for a multiple-parameter function will result in a very conservative CSA value. However, using a module calibration method for a complex, multiple-parameter function will result in an Allowable Value, LSSS/Setting Limit, or As Found Tolerance that
EE-0116 Page 23 of 205 Revision 7 is non-conservative. The rack error components for each Overtemperature T input channel are given below.
T Channel = (RCA1 + RMTE1) + RD1 + RTE1 TAVG Channel = (RCA2 + RMTE2) + RD2 + RTE2 Pressurizer Pressure Channel = (RCA3 + RMTE3) + RD3 + RTE3 FI Channel = (RCA4 + RMTE4) + RD4 + RTE4 OTT Setpoint = (RCA5 + RMTE5)
OTT Bistable = (RCSA + RMTE6)
Where:
RCA1 = T Channel Calibration Accuracy = + 0.707 % (M3)
RMTE1 = T Channel Rack Measuring and Test Equipment = + 0.173 % (M3MTE)
RD1 = T Channel Rack Drift = + 1.00 %
RTE1 = T Channel Rack Temperature Effect = + 0.50 %
RCA2 = TAVG Channel Calibration Accuracy = + 0.707 % (M4)
RMTE2 = TAVG Channel Rack Measuring and Test Equipment = + 0.245 % (M4MTE)
RD2 = TAVG Channel Rack Drift = + 1.00 %
RTE2 = TAVG Channel Rack Temperature Effect = + 0.50 %
RCA3 = Pressurizer Pressure Channel Calibration Accuracy = + 0.00 %
RMTE3 = Pressurizer Pressure Channel Rack Measuring and Test Equipment = + 0.0 %
RD3 = Pressurizer Pressure Channel Rack Drift = + 0.00 %
RTE3 = Pressurizer Pressure Channel Rack Temperature Effect = + 0.00 %
RCA4 = FI Channel Calibration Accuracy = + 0.50 % (M15)
RMTE4 = FI Channel Rack Measuring and Test Equipment = + 0.346 % (M15MTE)
RD4 = FI Channel Rack Drift = + 1.00 %
RTE4 = FI Channel Rack Temperature Effect = + 0.50 %
RCA5 = OTT Setpoint Summator Calibration Accuracy = + 0.50 % (M7)
RMTE5 = OTT Setpoint Summator Rack Measuring and Test Equipment = + 0.374 %
(M7MTE)
RCSA = OTT Reactor Trip Bistable = + 0.50 % (M18)
RMTE6 = OTT Reactor Trip Bistable Rack Measuring and Test Equipment = + 0.224 %
(M18MTE)
Some of the error terms listed above will be used to determine the Allowable Value (i.e., the As Found Tolerance) for Kewaunees Overtemperature T Reactor Trip. Similar error terms will be used throughout this document to evaluate the other multiple parameter protection functions at both plants.
EE-0116 Page 24 of 205 Revision 7 3.3 The Instrumentation, Systems and Automation Society (ISA) Methodologies Used to Calculate Allowable Values The following base line parameters will be used to illustrate how the Allowable Value is calculated using Methods 1, 2 and 3 from ISA-RP67.04.02-2000 and ISA-RP67.04-Part II-1994.
Analytical Limit (AL) = 6.00 PSIG Total Instrument Loop Uncertainty (TLU) = 1.39 PSIG Calculated Instrument Uncertainties used for COT (COT) = 1.10 PSIG Calculated Instrument Uncertainties not used for COT (NON-COT) = 0.85 PSIG Notes:
- 1. In the context of this document, the Analytical Limit (AL), Safety Limit (SL), and the Safety Analysis Limit (SAL) have the same meaning.
- 2. In the context of this document, Total Instrument Loop Uncertainty (TLU) and the Channel Statistical Allowance (CSA) have the same meaning.
- 3. COT means Channel Operational Test.
- 4. COT Instrument Uncertainties are made up of the portion of the loop that is tested during the COT.
For Surry, Kewaunee, and North Anna, these error components are:
- Rack or Module Calibration Accuracy (RCA or M1, M2 ... Mn)
- Rack Comparator Setting Accuracy or Comparator Module Calibration Accuracy (RCSA or Mn)
- Rack Drift (RD)
- 5. NON-COT Instrument Uncertainties are made up of the portion of the loop that is not tested during the COT. For Surry, Kewaunee, and North Anna, these error components may include:
- Systematic Error (SE)
- Environmental Allowance (EA)
- Process Measurement Accuracy (PMA)
- Primary Element Accuracy (PEA)
- Sensor Calibration Accuracy and Sensor Measuring and Test Equipment (SCA + SMTE)
- Sensor Drift (SD)
- Sensor Pressure Effect(s) (SPE)
- Sensor Temperature Effect (STE)
- Sensor Power Supply Effect (SPSE)
- Rack Measuring and Test Equipment (RMTE or M1MTE, M2MTE ... MnMTE)
- Rack Temperature Effect (RTE)
EE-0116 Page 25 of 205 Revision 7 3.3.1 Method 1 Method 1 has been evaluated by the NRC Staff and was found to be an acceptable method to be used to calculate Allowable Values. Method 1 uses a TLU equal to 1.39 PSIG. The TLU was arrived at statistically using the Square Root Sum of the Squares (SRSS) method of combining channel error components. This is an accepted industry standard and is used here at Dominion Virginia Power. The channel error components used for the COT are equal to 1.10 PSIG and the error components used for the NON-COT are equal to 0.85. With a TLU equal to 1.39 PSIG and NON-COT errors equal 0.85 PSIG, then statistically, the COT error would be equal to 1.10 PSIG as shown below.
[(0.85)2 + (1.10)2] 1/2 = 1.39 or [(1.39)2 - (0.85)2] 1/2 = 1.10 If the COT error allowance were to be removed from the TLU, the statistical combination of the NON-COT error allowances would be equal to 0.85 PSIG. This means that the LSSS would have to be set such that the margin of 0.85 PSIG is maintained between the AV and the AL. To accomplish this using a COT error allowance of 1.10 PSIG, a determinant assessment must be used such that the COT allowance can only be equal to the TLU minus the NON-COT allowance, i.e., COT = 1.39 PSIG - 0.85 PSIG = 0.54 PSIG. In Method 1, the user decides that for the Channel Operational Test, the full COT allowance of 1.10 PSIG is to be retained. To maintain the full COT error allowance, the actual trip setpoint (ACT SP) is set below the calculated trip setpoint (CAL SP). Note that the difference between the CAL SP and the Allowable Value (AV) is 0.54 PSIG. The remainder of the desired COT allowance of 1.10 PSIG is obtained by lowering the ACT SP below the CAL SP by 0.56 PSIG to yield the ACT SP value of 4.05 PSIG. Method 1 ensures that the full NON-COT allowance of 0.85 PSIG is available under all conditions for the non-tested channel error components.
METHOD 1:
AL = 6.00 PSIG NON COT = 0.85 TLU = 1.39 AV = 5.15 PSIG COT = 1.10 CAL SP = 4.61 PSIG ACT SP = 4.05 PSIG LEGEND: TLU = TOTAL LOOP UNCERTAINTY AL = ANALYTICAL LIMIT (SAL) AV = ALLOWABLE VALUE NON COT = NON TESTED LOOP UNCERTAINTY COT = TESTED LOOP UNCERTAINTY CAL SP = CALCULATED SETPOINT ACT SP = ACTUAL SETPOINT Figure 3.3-1
EE-0116 Page 26 of 205 Revision 7 3.3.2 Method 2 Method 2 has been evaluated by the NRC Staff and was found to be an acceptable method to be used to calculate Allowable Values. Method 2 is essentially the same as Method 1 with the exception that the ACT SP is set equal to the CAL SP (i.e., 4.61 PSIG). This method does not allow for the full value of the COT error components as determined in the TLU (i.e., CSA Calculation). In some cases, this could cause the plant to find the AS FOUND Trip Setpoint outside of the AV more often than would be the case using Method 1. Like Method 1, Method 2 ensures that the statistical combination of the NON-COT error allowances (equal to 0.85 PSIG) is maintained between the AV and the AL under all conditions.
METHOD 2:
AL = 6.00 PSIG NON COT = 0.85 TLU = 1.39 AV = 5.15 PSIG COT = 0.54 CAL & ACT SP = 4.61 PSIG LEGEND: TLU = TOTAL LOOP UNCERTAINTY AL = ANALYTICAL LIMIT (SAL) AV = ALLOWABLE VALUE NON COT = NON TESTED LOOP UNCERTAINTY COT = TESTED LOOP UNCERTAINTY CAL SP = CALCULATED SETPOINT ACT SP = ACTUAL SETPOINT Figure 3.3-2 3.3.3 Method 3 Method 3 has been evaluated by the NRC Staff and was found to be an unacceptable method to be used to calculate Allowable Values. Method 3 has been used to calculate the Allowable Value in many Westinghouse Plants that used early versions of Standardized Technical Specifications (STS) as discussed above in Section 3.1. Using a determinant assessment, Method 3 does not ensure that the full NON-COT uncertainty allowance is maintained between the AV and the AL. To ensure that the NON-COT uncertainty allowance is maintained under all conditions, the AV must be set for < 5.15 PSIG. As can be seen from the illustration below, the AV using Method 3 is set for 5.71 PSIG, i.e., CAL SP/ACT SP + COT
= 5.71 PSIG. If the rack error components are allowed an offset of 1.10 PSIG before the channel is declared INOPERABLE, then the allowance for the NON-COT uncertainty is decreased to 0.29 PSIG. If the AS FOUND COT error was found to be (+) 1.05 PSIG and the AS FOUND NON-COT error was determined to be (+) 0.85 PSIG, then the channel trip function would have exceeded the Analytical Limit (i.e., SAL) and should be declared INOPERABLE. However, in accordance with Technical Specifications, the channel does not have to be declared INOPERABLE until the AS FOUND Trip Setpoint exceeds the Allowable Value. This is the concern that the NRC Staff has with Method 3. In the case of Method 3 using
EE-0116 Page 27 of 205 Revision 7 a determinant assessment, the AV does not protect the AL and does not identify an inoperable channel under all operating conditions.
METHOD 3:
AL = 6.00 PSIG NON COT = 0.29 TLU = 1.39 AV = 5.71 PSIG COT = 1.10 CAL & ACT SP = 4.61 PSIG LEGEND: TLU = TOTAL LOOP UNCERTAINTY AL = ANALYTICAL LIMIT (SAL) AV = ALLOWABLE VALUE NON COT = NON TESTED LOOP UNCERTAINTY COT = TESTED LOOP UNCERTAINTY CAL SP = CALCULATED SETPOINT ACT SP = ACTUAL SETPOINT Figure 3.3-3 3.3.4 Method 3 with Additional Margin Method 3 using additional margin for the ACT SP has been evaluated by the NRC Staff and was found to be an unacceptable method to be used to calculate Allowable Values. Method 3 with additional margin is identical to Method 3 with the exception that the ACT SP is set below the CAL SP. In the case used for this illustration, the ACT SP is set for 4.00 PSIG which provides a margin of 0.61 PSIG to the CAL SP and 1.71 PSIG to the AV. This method actually yields less conservative results than Method 3 for two reasons. First, the AV is still set for 5.71 PSIG yielding a NON-COT allowance of 0.29 PSIG. As discussed above, using a determinant assessment, the NON-COT allowance of 0.29 PSIG does not fully account for the statistical combination of the non-tested loop error components.
Second, the calculated COT allowance was determined to be 1.10 PSIG. Allowing an error of 1.71 PSIG between the ACT SP and the AV is beyond the assumptions used to develop the TLU (i.e., CSA Calculation). Allowing an error of 1.71 PSIG for the Trip Setpoint before the channel is declared INOPERABLE is inconsistent with the applicable TLU assumptions and will not ensure that the rack components are operating within the assumptions of the CSA Calculation and/or the manufacturer specifications. Also note that the difference between the ACT SP and the AV is larger than the calculated TLU for the entire channel.
EE-0116 Page 28 of 205 Revision 7 METHOD 3 WITH ADDITIONAL MARGIN:
AL = 6.00 PSIG NON COT = 0.29 TLU = 1.39 AV = 5.71 PSIG COT = 1.1 CAL SP = 4.61 PSIG ACT SP = 4.00 PSIG LEGEND: TLU = TOTAL LOOP UNCERTAINTY AL = ANALYTICAL LIMIT (SAL) AV = ALLOWABLE VALUE NON COT = NON TESTED LOOP UNCERTAINTY COT = TESTED LOOP UNCERTAINTY CAL SP = CALCULATED SETPOINT ACT SP = ACTUAL SETPOINT Figure 3.3-4
EE-0116 Page 29 of 205 Revision 7 3.4 Methodology for Determining North Anna Allowable Values and Surry LSSS/Setting Limits 3.4.1 Primary RTS and ESFAS Trips and Permissives Credited in the Safety Analysis A four step process is used to determine Allowable Values, Limiting Safety System Settings (LSSS), or Setting Limits for Primary RTS and ESFAS Trip Functions and Permissives at North Anna and Surry Power Stations that are credited in the Safety Analysis. This four step process is based on the requirements of Methods 1 or 2 as described in ISA-RP67.04.02-2000 (Ref 5.43). In the order of operation, the four steps are described below and they are illustrated in Figure 3.4-1
- 1. Determine the Minimum (decreasing trip) or Maximum (increasing trip) Trip Setpoint (MTS). The Maximum Trip Setpoint is arrived at by subtracting the Total Loop Uncertainty (TLU) from the Analytical Limit (AL). The Minimum Trip Setpoint is arrived at by adding the Total Loop Uncertainty (TLU) to the Analytical Limit (AL).
- 2. Determine the Minimum (decreasing trip) or Maximum (increasing trip) Allowable Value/LSSS/Setting Limit (MAV). This Minimum Allowable Value/LSSS/Setting Limit is arrived at by adding the statistical combination (i.e., Square Root of the Sum of the Squares SRRS) of the NON COT Loop Error Components (i.e., the loop error terms that are not tested or quantified during the Channel Operational Test COT) to the Analytical Limit (AL). The Maximum Allowable Value/LSSS/Setting Limit is arrived at by subtracting the statistical combination of the NON COT Loop Error Components from the Analytical Limit (AL).
- 3. Determine the Actual Trip Setpoint (ATS). After the MTS is determined in step 1, the current Nominal Trip Setpoint for the function can be evaluated for acceptability. It may be desirable to move the current Nominal Trip Setpoint in a more conservative direction to obtain additional margin to the Analytical Limit and/or to allow for the full COT error allowance between the Actual Trip Setpoint and the Actual Allowable Value. Conversely, the current Nominal Trip Setpoint may be overly conservative resulting in reduced operating margin. If there is sufficient margin to the Analytical Limit, then it may be desirable to move the existing Nominal Trip Setpoint in the non-conservative direction to obtain additional operating margin. In all cases, the ATS must be set equal to or, preferably, conservative with respect to the MTS.
- 4. Determine the Actual Allowable Value (AV). After MAV is determined in step 2, the Actual Allowable Value can be determined based on the ATS. The AV for an increasing trip function is arrived at by adding the statistical combination (i.e., Square Root of the Sum of the Squares SRRS) of the COT Loop Error Components (i.e., the loop error terms that are tested or quantified during the Channel Operational Test COT) to the Actual Trip Setpoint (ATS). The AV for a decreasing trip function is arrived at by subtracting the statistical combination of the COT Loop Error Components from the Actual Trip Setpoint (ATS). In all cases, the AV must be set equal to or, preferably, conservative with respect to the MAV.
EE-0116 Page 30 of 205 Revision 7 FOUR STEP PROCESS FOR INCREASING TRIP Analytical Limit (AL)
NON COT ERRORS TOTAL LOOP UNCERTAINTY (TLU) Maximum Allowable Value (MAV)
(STEP 2)
COT ERRORS Maximum Trip Setpoint (MTS)
(STEP 1)
Actual Allowable Value (AV)
(STEP 4)
MARGIN COT ERRORS Actual Trip Setpoint (ATS)
(STEP 3)
Figure 3.4-1 3.4.2 Backup RTS and ESFAS Trips and Permissives Not Credited in the Safety Analysis A two step process is used to determine Allowable Values, LSSS, or Setting Limits for Backup RTS and ESFAS Functions at North Anna and Surry Power Stations that are not credited in the Safety Analysis.
Backup RTS and ESFAS Trip Functions do not have a documented Analytical Limit; therefore, Minimum/Maximum Trip Setpoints and Allowable Values do not need to be calculated. In some cases for Backup Trips, a TLU (i.e., CSA Calculation) may not be available to perform the process described below.
In such a case, the process is subjective and should be based on the best available information. The two step process is described below.
- 1. Determine the Actual Trip Setpoint (ATS). The current Nominal Trip Setpoint for the function should be evaluated for acceptability. It may be desirable to move the current Nominal Trip Setpoint in a more conservative direction to obtain additional margin to ensure the function will support the associated Primary Trip, if applicable. Conversely, the current Nominal Trip Setpoint may be overly conservative resulting in reduced operating margin. If there is sufficient margin with respect to the associated Primary Trip Analytical Limit (if applicable), then it may be desirable to move the existing Nominal Trip Setpoint in the non-conservative direction to obtain additional operating margin.
EE-0116 Page 31 of 205 Revision 7
- 2. Determine the Actual Allowable Value (AV). The AV for an increasing trip function is arrived at by adding the statistical combination (i.e., Square Root of the Sum of the Squares SRRS) of the COT Loop Error Components (i.e., the loop error terms that are tested or quantified during the Channel Operational Test COT) to the Actual Trip Setpoint (ATS). The AV for a decreasing trip function is arrived at by subtracting the statistical combination of the COT Loop Error Components from the Actual Trip Setpoint (ATS).
3.4.3 Calculating Actual Allowable Values for North Anna and LSSS/Setting Limits for Surry The existing Allowable Values for North Anna and LSSS/Setting Limit Values for Surry will be evaluated to determine if they are acceptable based on the requirements of Methods 1 or 2 as described in ISA-RP67.04.02-2000 (Ref 5.43). Examples of the methodology used for North Anna and Surry are provided below.
North Anna The current Allowable Value for North Annas Pressurizer High Water Level Reactor Trip that appears in Improved Technical Specifications (Ref 5.8) will be evaluated based on the four step method described in Section 3.4.1 to ensure that it is bounded by the CSA Calculation of record and by the Safety Analysis assumptions documented in Technical Report NE-0994 (Ref. 5.1).
Given Information:
Analytical Limit/Safety Analysis Limit = 100.0 % Narrow Range Level (Ref. 5.1)
Current Allowable Value = < 93.0 % Narrow Range Level (Ref. 5.8)
Current Trip Setpoint = 92.0 % Narrow Range Level (Refs. 5.2 & 5.54)
Total Loop Uncertainty/Channel Statistical Allowance = + 6.887 % Narrow Range Level (Ref. 5.20)
Type of Trip = Increasing Trip, Normally Energized (Ref. 5.54)
Functional Group = Primary Trip, Single Parameter Protection Function (Refs. 5.1, 5.2 & 5.54)
Step 1 - Determine the Maximum (increasing trip) Trip Setpoint (MTS)
The Maximum Trip Setpoint (MTS) is equal to the Analytical Limit (AL) minus the Total Loop Uncertainty (TLU). Thus, the MTS is equal to:
MTS = 100.0 % - 6.887 %
MTS = 93.113 % Narrow Range Level
EE-0116 Page 32 of 205 Revision 7 Step 2 - Determine the Maximum Allowable Value (MAV)
The Maximum Allowable Value (MAV) is equal to the Analytical Limit (AL) minus the NON-COT loop error components taken from the Total Loop Uncertainty (TLU) calculation. The NON-COT loop error components from CSA Calculation EE-0058, (Ref. 5.20) are detailed below:
Process Measurement Accuracy (PMA) = + 2.000 % of span Primary Element Accuracy (PEA) = + 0.000 % of span Sensor Calibration Accuracy + Sensor Measuring & Test Equipment (SCA+SMTE) = + 0.744 % of span Sensor Drift (SD) = + 0.788 % of span Sensor Pressure Effects (SPE) + 5.917 % of span Sensor Temperature Effects (STE) = + 2.418 % of span Sensor Power Supply Effect (SPSE) = + 0.000 % of span Module 1 Measuring and Test Equipment (M1MTE) = + 0.153 % of span Module 2 Measuring and Test Equipment (M2MTE) = + 0.03 % of span Rack Temperature Effect (RTE) = + 0.500 % of span Combining the NON-COT loop error components using the Square Root of the Sum of the Squares (SRSS) method as described in Dominion Standard STD-EEN-0304 (Ref. 5.5), we have the following NON-COT total error:
NON-COTerror = + [PMA2 + PEA2 + (SCA+SMTE)2 + SD2 + SPE2 + STE2 + SPSE2 + M1MTE2 +
M2MTE2 + RTE2] 1/2 NON-COTerror = + [2.02 + 0.02 + (0.5+0.244)2 + 0.7882 + 5.9172 + 2.4182 + 0.02 + 0.1532 + 0.032 +
0.52] 1/2 NON-COTerror = + 6.805 % Narrow Range Level The Maximum Allowable Value (MAV) for an increasing trip based on the requirements of Methods 1 or 2 as described in ISA-RP67.04.02-2000 (Ref. 5.43) is determined by subtracting the total NON-COT error from the Analytical Limit as shown below.
MAV = 100.0 % - 6.805 %
MAV = 93.195 % Narrow Range Level Step 3 - Determine the Actual Trip Setpoint (ATS)
As determined in Step 1, the Maximum Trip Setpoint is equal to 93.113 % Narrow Range Level. The current Nominal Trip Setpoint for this function is 92.0 % Narrow Range Level. The current setpoint is conservative with respect to the Maximum Trip Setpoint. The nominal operating band for pressurizer level at 100 % power is 64.5 % Level + 5.0 % Level. Subtracting the worst case normal operating level of 69.5
% from the Nominal Trip Setpoint of 92.0 % yields an operating margin of 22.5 % level. This operating margin encompasses the entire Total Loop Uncertainty and should allow for stable operation. Therefore, the current Nominal Trip Setpoint of 92.0 % Narrow Range Level will be retained.
EE-0116 Page 33 of 205 Revision 7 Step 4 - Determine the Actual Allowable Value (AV)
For a single input protection function, the Allowable Value will be determined based on the following rack error components :
- Rack Calibration Accuracy (RCA)
- Rack Comparator Setting Accuracy (RCSA)
- Rack Drift (RD)
Note : The RCA and RCSA terms used above are typically defined in Dominion CSA Calculations as Module Tolerances and are designated as M1, M2 Mn. For the purposes of this report, the Terms RCA1, RCA2, RCAn and RCSA are the same as M1, M2 and Mn as used in the CSA Calculations.
There are two rack error terms that are not included in the calculation of the Allowable Value, Rack Measuring and Test Equipment (RMTE) and Rack Temperature Effect (RTE). These rack error terms are not included because they cannot be evaluated/quantified during the performance of the COT.
Normally, M&TE is checked on a periodic basis (i.e., every quarter, six months or year). Rack Temperature Effects are not really ever checked or quantified. The Emergency Switchgear Room (the Relay Room at Kewaunee) is designed to maintain a relatively constant temperature. If the temperature changes by more than a nominal amount, the effects on the process instrumentation are normally not evaluated unless a loop or loops are deviating from their nominal process value(s) as indicated in the control room. In addition, by not using these error components, the calculated Allowable Value will be more conservative and easily quantified during or immediately subsequent to functional testing.
The methodology used to calculate the Allowable Value will be based on the Square Root Sum of the Squares (SRSS) of the three rack error terms listed above, noting that each rack error term will be treated as an independent variable. This method will yield a Rack Allowance and thus an Allowable Value that will be consistent with the assumptions of the CSA Calculation of record. Note the example below using the North Anna Pressurizer High Water Level Reactor Trip.
As determined in Step 2, the Maximum Allowable Value is equal to 93.195 % Narrow Range Level. The current ITS Allowable Value for this function is < 93.0 % Narrow Range Level. The current ITS Allowable Value is conservative with respect to the Maximum Allowable Value (MAV) and is also conservative with respect to the calculated Allowable Value if it were based on the COT error components taken from Calculation EE-0058 (Ref. 5.20) as shown below.
The Actual Allowable Value (AV) is equal to the Actual Trip Setpoint plus the COT loop error components taken from the Total Loop Uncertainty (TLU) calculation. The COT loop error components from CSA Calculation EE-0058, (Ref. 5.20) are detailed below:
Module 1 - Westinghouse NLPG02 or NLPG05 Card (M1) = + 0.10 % of span Module 2 - Westinghouse NALG02 Card (M2) = + 0.25 % of span Rack Drift (RD) = + 1.0 % of span
EE-0116 Page 34 of 205 Revision 7 Combining the COT loop error components using the Square Root of the Sum of the Squares (SRSS) method as described in Dominion Standard STD-EEN-0304 (Ref. 5.5), we have the following COT total error:
COTerror = + (M12 + M22 + RD2) 1/2 COTerror = + (0.102 + 0.252 + 1.02) 1/2 COTerror = + 1.036 % Narrow Range Level As described in Step 4 above, the Actual Allowable Value (AV) for an increasing trip is determined by adding the total COT error to the Actual Trip Setpoint as shown below.
AV = 92.0 % + 1.036 %
AV = 93.036 % Narrow Range Level The calculated Actual Allowable Value of 93.036 % Narrow Range Level will be rounded back to 93.0
% Narrow Range Level which is consistent with the current ITS Allowable Value for this function.
Thus, the Actual Allowable Value for North Anna Pressurizer High Water Level Reactor Trip is:
AV = < 93.0 % Narrow Range Level Steps 1 through 4 as they apply for North Annas Pressurizer High Water Level Reactor Trip are illustrated below in Figure 3.4-3a.
EE-0116 Page 35 of 205 Revision 7 NORTH ANNA'S PRESSURIZER HIGH WATER LEVEL REACTOR TRIP Analytical Limit (AL) 100.00 NR Level TOTAL LOOP NON-COT ERRORS 6.805 % NR Level 6.887 % NR Level Maximum Allowable Value (MAV)
UNCERTAINTY (TLU) 93.195 % NR Level COT ERRORS 0.082 % NR Level Maximum Trip Setpoint (MTS) 93.113 % NR Level Actual Allowable Value (AV)
SAFETY MARGIN 93.00 % NR Level COT ERRORS 1.00 % NR 1.113 % NR Level Level Actual Trip Setpoint (ATS) 92.00 % NR Level OPERATING MARGIN 22.50 % NR Level High Operating Limit 69.50 % NR Level Nominal Operating Setpoint 64.50 % NR Level Figure 3.4-3a Surry The current Limiting Safety System Setting (LSSS) for Surrys Pressurizer High Water Level Reactor Trip that appears in Custom Technical Specifications (Ref. 5.7) will be evaluated based on the four step method described in Section 3.4.1 to ensure that it is bounded by the CSA Calculation of record and by the Safety Analysis assumptions documented in Technical Report NE-0994 (Ref. 5.1).
Given Information:
Analytical Limit/Safety Analysis Limit = 100.0 % Narrow Range Level (Ref. 5.1)
Current Allowable Value (i.e., LSSS) = < 92.0 % Narrow Range Level (Ref. 5.7)
Current Trip Setpoint = 88.0 % Narrow Range Level (Refs. 5.2 & 5.67)
EE-0116 Page 36 of 205 Revision 7 Total Loop Uncertainty/Channel Statistical Allowance = + 7.894 % Narrow Range Level (Ref. 5.33)
Type of Trip = Increasing Trip, Normally Energized (Ref. 5.67)
Functional Group = Primary Trip, Single Parameter Protection Function (Refs. 5.1, 5.2 & 5.67)
Step 1 - Determine the Maximum (increasing trip) Trip Setpoint (MTS)
The Maximum Trip Setpoint (MTS) is equal to the Analytical Limit (AL) minus the Total Loop Uncertainty (TLU). Thus, the MTS is equal to:
MTS = 100.0 % - 7.894 %
MTS = 92.106 % Narrow Range Level Step 2 - Determine the Maximum Allowable Value (MAV)
The Maximum Allowable Value (MAV) is equal to the Analytical Limit (AL) minus the NON-COT loop error components taken from the Total Loop Uncertainty (TLU) calculation. The NON-COT loop error components from CSA Calculation EE-0458 (Ref. 5.33) are detailed below:
Process Measurement Accuracy (PMA) = + 2.000 % of span Primary Element Accuracy (PEA) = + 0.000 % of span Sensor Calibration Accuracy + Sensor Measuring & Test Equipment (SCA+SMTE) = + 0.817 % of span Sensor Drift (SD) = + 0.838 % of span Sensor Pressure Effects (SPE) + 6.984 % of span Sensor Temperature Effects (STE) = + 2.550 % of span Sensor Power Supply Effect (SPSE) = + 0.000 % of span Module 1 Measuring and Test Equipment (M1MTE) = + 0.00 % of span Module 4 Measuring and Test Equipment (M4MTE) = + 0.150 % of span Rack Temperature Effect (RTE) = + 0.500 % of span Combining the NON-COT loop error components using the Square Root of the Sum of the Squares (SRSS) method as described in Dominion Standard STD-EEN-0304 (Ref. 5.5), we have the following NON-COT total error:
NON COTerror = + [PMA2 + PEA2 + (SCA+SMTE)2 + SD2 + SPE2 + STE2 + SPSE2 + M1MTE2 +
M4MTE2 + RTE2] 1/2 NON COTerror = + [2.02 + 0.02 + (0.5+0.317)2 + 0.8382 + 6.9842 + 2.5502 + 0.02 + 0.02 + 0.1502 +
0.52] 1/2 NON COTerror = + 7.805 % Narrow Range Level
EE-0116 Page 37 of 205 Revision 7 The Maximum Allowable Value (MAV) for an increasing trip based on the requirements of Methods 1 or 2 as described in ISA-RP67.04.02-2000 (Ref. 5.43) is determined by subtracting the total NON-COT error from the Analytical Limit as shown below.
MAV = 100.0 % - 7.805 %
MAV = 92.195 % Narrow Range Level Step 3 - Determine the Actual Trip Setpoint (ATS)
As determined in Step 1, the Maximum Trip Setpoint is equal to 92.106 % Narrow Range Level. The current Nominal Trip Setpoint for this function at Surry is 88.0 % Narrow Range Level. The current setpoint is conservative with respect to the Maximum Trip Setpoint. The nominal operating band for pressurizer level at 100 % power is 53.7 % Level + 5.0 % Level. Subtracting the worst case normal operating level of 58.7 % from the Nominal Trip Setpoint of 88.0 % yields an operating margin of 29.3 %
level. This operating margin encompasses the entire Total Loop Uncertainty and should allow for stable operation. Therefore, the current Nominal Trip Setpoint of 88.0 % Narrow Range Level will be retained.
Step 4 - Determine the Actual Allowable Value (AV)
As determined in Step 2, the Maximum Allowable Value is equal to 92.195 % Narrow Range Level. The current LSSS value for this function is < 92.0 % Narrow Range Level. The current LSSS value is conservative with respect to the Maximum Allowable Value (MAV) however; it is non-conservative with respect to the calculated Allowable Value if it were based on the COT error components taken from Calculation EE-0458 (Ref. 5.33) as shown below.
The Actual Allowable Value (i.e., LSSS) is equal to the Actual Trip Setpoint plus the COT loop error components taken from the Total Loop Uncertainty (TLU) calculation. The COT loop error components from CSA Calculation EE-0458 (Ref. 5.33) are detailed below:
Module 1 - Technipower PM-38 or NUS LPS801 Loop Power Supply (M1) = + 0.00 % of span Module 4 - Hagan Model 139-118 or NUS SAM/DAM 801 Module (M4) = + 0.50 % of span Rack Drift (RD) = + 1.0 % of span Combining the COT loop error components using the Square Root of the Sum of the Squares (SRSS) method as described in Dominion Standard STD-EEN-0304 (Ref. 5.5), we have the following COT total error:
COTerror = + (M12 + M42 + RD2) 1/2 COTerror = + (0.02 + 0.52 + 1.02) 1/2 COTerror = + 1.12 % Narrow Range Level
EE-0116 Page 38 of 205 Revision 7 As described in Step 4 above, the Actual Allowable Value (AV) for an increasing trip is determined by adding the total COT error to the Actual Trip Setpoint as shown below.
AV = 88.00 % + 1.12 % = 89.12 % Narrow Range Level The current CTS LSSS of < 92.0 % Narrow Range Level will be changed to < 89.12 % Narrow Range Level as shown above.
AV (i.e., LSSS) = < 89.12 % Narrow Range Level Steps 1 through 4 as they apply for Surrys Pressurizer High Water Level Reactor Trip are illustrated below in Figure 3.4-3b.
SURRY'S PRESSURIZER HIGH WATER LEVEL REACTOR TRIP Analytical Limit (AL) 100 % NR Level COT ERRORS NON-COT ERRORS TOTAL LOOP 7.805 % NR Level 7.894 % NR Level Maximum Allowable Value (MAV)
UNCERTAINTY (TLU) 92.195 % NR Level 0.089 % NR Level Maximum Trip Setpoint (MTS) 92.106 % NR Level Actual Allowable Value (AV) 89.12 % NR Level COT ERRORS SAFETY MARGIN 1.12 % NR 4.106 % NR Level Level Actual Trip Setpoint (ATS) 88.00 % NR Level OPERATING MARGIN 29.30 % NR Level High Operating Limit 58.70 % NR Level Nominal Operating Setpoint 53.70 % NR Level Figure 3.4-3b
EE-0116 Page 39 of 205 Revision 7 3.5 Methodology for Determining Kewaunees Allowable Value and Limiting Trip Setpoint Based on TSTF-493 and RIS 2006-17 Kewaunees setpoint methodology is identical to that of Surry and North Anna noting that the requirements and revised terminology imposed by TSTF-493 and RIS 2006-17 (Refs. 5.99 and 5.100) will be incorporated into the methodology as appropriate. Kewaunee Power Station has chosen to implement TSTF-493, Revision 4, Option B as part of the conversion to Improved Technical Specifications. As stated above in Section 2.2.6, TSTF-493, Revision 4, Option B allows for the relocation of the Allowable Values associated with LCOs 3.3.1, 3.3.2, 3.3.5, 3.3.6, and 3.3.7 from Section 3.3 of Technical Specifications to a Licensee controlled program as defined in ITS Section 5.5.16. The Licensee controlled program is defined in ITS Section 5.5.16 as the Setpoint Control Program.
The Setpoint Control Program establishes the requirements for ensuring that setpoints for automatic protective devices are initially within and remain within the Technical Specification requirements. The Setpoint Control Program will govern the process for implementing changes to instrumentation setpoints and will describe the setpoint methodology used to ensure that setpoints are established in accordance with the requirements of Methods 1 or 2 from ISA-RP67.04.02-2000 and ISA-RP67.04-Part II-1994, TSTF-493, Revision 4, Option B, and RIS 2006-17. The automatic protective devices related to variables that perform a significant safety function at Kewaunee Power Station as delineated by 10 CFR 50.36(c)(1)(ii)(A) are described in detail in Sections 4.5, 4.6, and 4.7.
3.5.1 Primary RPS and ESFAS Trips, Permissives, and Other LCOs Credited in the Kewaunee Safety Analysis A four step process is used to determine the Allowable Value (AV), Limiting Trip Setpoint (LTSP),
Nominal Trip Setpoint (NTSP), and the As Found Tolerance (AFT) for Trip Functions, Permissives, and other LCOs at Kewaunee Power Station that are credited in the Safety Analysis. This four step process is based on the requirements of Methods 1 or 2 as described in ISA-RP67.04.02-2000 (Ref 5.43) and the revised terminology described in TSTF-493, Revision 4, and RIS 2006-17. In the order of operation, the four steps are described below and they are illustrated in Figure 3.5-1
- 1. Determine the Minimum (decreasing trip) or Maximum (increasing trip) Limiting Trip Setpoint (LTSP). The Maximum Limiting Trip Setpoint is arrived at by subtracting the Total Loop Uncertainty (TLU) from the Analytical Limit (AL) (also known as the Safety Analysis Limit). The Minimum Limiting Trip Setpoint is arrived at by adding the Total Loop Uncertainty (TLU) to the Analytical Limit (AL).
- 2. Determine the Minimum (decreasing trip) or Maximum (increasing trip) Allowable Value (AV).
This Maximum Allowable Value is arrived at by subtracting the statistical combination (i.e., Square Root of the Sum of the Squares SRRS) of the NON COT Loop Error Components (i.e., the loop error terms that are not tested or quantified during the Channel Operational Test COT) from the Analytical Limit (AL). The Minimum Allowable Value is arrived at by adding the statistical combination of the NON COT Loop Error Components to the Analytical Limit (AL).
EE-0116 Page 40 of 205 Revision 7
- 3. Determine the Nominal Trip Setpoint (NTSP). After the LTSP is determined in step 1, the current Nominal Trip Setpoint for the function can be evaluated for acceptability. It may be desirable to move the current Nominal Trip Setpoint in a more conservative direction to obtain additional margin to the Analytical Limit and/or to allow for the full COT error allowance between the Nominal Trip Setpoint and the As Found Tolerance (AFT). Conversely, the current Nominal Trip Setpoint may be overly conservative resulting in reduced operating margin. If there is sufficient margin to the Analytical Limit, then it may be desirable to move the existing Nominal Trip Setpoint in the non-conservative direction to obtain additional operating margin. In all cases, the NTSP must be set equal to or, preferably, conservative with respect to the LTSP.
- 4. Determine the As Found Tolerance (AFT). Note that the As Found Tolerance for Kewaunee is equivalent to the Allowable Values/Limiting Safety System Settings/Setting Limits used for North Anna and Surry. After the AV is determined in step 2, the As Found Tolerance can be determined based on the NTSP. The AFT for an increasing trip function is arrived at by adding the statistical combination (i.e., Square Root of the Sum of the Squares SRRS) of the COT Loop Error Components (i.e., the loop error terms that are tested or quantified during the Channel Operational Test COT) to the Nominal Trip Setpoint (NTSP). The AFT for a decreasing trip function is arrived at by subtracting the statistical combination of the COT Loop Error Components from the Nominal Trip Setpoint. In all cases, the As Found Tolerance must be set equal to or, preferably, conservative with respect to the Allowable Value.
Kewaunee's Four Step Process Analytical Limit (AL)
NON COT ERRORS TOTAL LOOP UNCERTAINTY (TLU) Allowable Value (AV)
(STEP 2)
COT ERRORS Limiting Trip Setpoint (LTSP)
(STEP 1)
As Found Tolerance (AFT)
(STEP 4)
MARGIN COT ERRORS Nominal Trip Setpoint (NTSP)
(STEP 3)
Figure 3.5-1
EE-0116 Page 41 of 205 Revision 7 3.5.2 Backup RPS and ESFAS Trips, Permissives, and Other LCOs Not Credited in the Kewaunee Safety Analysis A two step process is used to determine the As Found Tolerance for Backup RPS and ESFAS Functions at Kewaunee Power Station that are not credited in the Safety Analysis. Backup RPS/ ESFAS and other LCOs Trip Functions do not have a documented Safety Limit; therefore, Limiting Trip Setpoints and Allowable Values do not need to be calculated. In some cases for Backup Trips, a TLU (i.e., CSA Calculation) may not be available to perform the process described below. In such a case, the process is subjective and should be based on the best available information. The two step process is described below.
- 1. Determine the Nominal Trip Setpoint (NTSP). The current Nominal Trip Setpoint for the function should be evaluated for acceptability. It may be desirable to move the current Nominal Trip Setpoint in a more conservative direction to obtain additional margin to ensure the function will support the associated Primary Trip, if applicable. Conversely, the current Nominal Trip Setpoint may be overly conservative resulting in reduced operating margin. If there is sufficient margin with respect to the associated Primary Trip Analytical Limit (if applicable), then it may be desirable to move the existing Nominal Trip Setpoint in the non-conservative direction to obtain additional operating margin.
- 2. Determine the As Found Tolerance (AFT). The AFT for an increasing trip function is arrived at by adding the statistical combination (i.e., Square Root of the Sum of the Squares SRRS) of the COT Loop Error Components (i.e., the loop error terms that are tested or quantified during the Channel Operational Test COT) to the Nominal Trip Setpoint (NTSP). The AFT for a decreasing trip function is arrived at by subtracting the statistical combination of the COT Loop Error Components from the Nominal Trip Setpoint (NTSP).
EE-0116 Page 42 of 205 Revision 7 3.5.3 Calculating Limiting Trip Setpoints, Allowable Values, and As Found Tolerances for Kewaunee Power Station Kewaunees Steam Generator Water Level High - High Currently, Kewaunees Custom Technical Specifications (Ref. 5.90) does not specify a Setting Limit for the Steam Generator High-High Water Level ESFAS Trip. This function will be included in the Setpoint Control Program in accordance with ITS Table 3.3.2.1, item 5.b. Based on the requirements of ITS Section 5.5.16, this function will be evaluated based on the four step method described in Section 3.5.1 to ensure that it is bounded by the CSA Calculation of record and by the Safety Analysis assumptions documented in Technical Report NE-0994 (Ref. 5.1). The example given below will be adjusted to include the revised terminology and requirements specified in TSTF-493, Revision 4 and RIS 2006-17 to support the conversion to ITS and the implementation of the Kewaunee Setpoint Control Program.
Given Information:
Analytical Limit = 100.0 % Narrow Range Level (Ref. 5.1)
Current CTS Setting Limit = not specified Current Nominal Trip Setpoint = 66.5 % Narrow Range Level (Ref. 5.112)
Total Loop Uncertainty/Channel Statistical Allowance = (+) 3.967 to (+) 7.923 % Narrow Range Level (only the most positive value is used for the analysis) (Ref. 5.97)
Type of Trip = Increasing Trip, Normally Energized (Ref. 5.112)
Functional Group = Primary Trip, Single Parameter Protection Function (Refs. 5.1 and 5.112)
Step 1 - Determine the Limiting Trip Setpoint (LTSP)
The Limiting Trip Setpoint (LTSP) is equal to the Analytical Limit (AL) minus the Total Loop Uncertainty (TLU). Thus, the LTSP is equal to:
LTSP = 100.0 % - 7.923 %
LTSP = 92.077 % Narrow Range Level Step 2 - Determine the Allowable Value (AV)
The Allowable Value (AV) is equal to the Analytical Limit (AL) minus the NON-COT loop error components taken from the Total Loop Uncertainty (TLU) calculation. The NON-COT loop error components from Kewaunee CSA Calculation C11116 (Ref. 5.97) are detailed below:
EE-0116 Page 43 of 205 Revision 7 Systematic Error (SE) = + 0.000 % of span Process Measurement Accuracy (PMA3) = + 5.945 % of span Primary Element Accuracy (PEA) = + 0.000 % of span Sensor Calibration Accuracy + Sensor Measuring & Test Equipment (SCA+SMTE) = + 0.467 % of span Sensor Drift (SD) = + 0.280 % of span Sensor Pressure Effects (SPE) + 0.577 % of span Sensor Temperature Effects (STE) = + 1.241 % of span Sensor Power Supply Effect (SPSE) = + 0.060 % of span Module 1 Measuring and Test Equipment (M1MTE) = + 0.000 % of span Module 3 Measuring and Test Equipment (M3MTE) = + 0.200 % of span Rack Temperature Effect (RTE) = + 0.500 % of span Combining the NON-COT loop error components using the Square Root of the Sum of the Squares (SRSS) method as described in Dominion Standard STD-EEN-0304 (Ref. 5.5), we have the following NON-COT total error:
NON COTerror = SE + PMA3 + [PEA2 + (SCA+SMTE)2 + SD2 + SPE2 + STE2 + SPSE2 + M1MTE2 +
M3MTE2 + RTE2] 1/2 NON COTerror = 0.0 + 5.945 + [0.02 + (0.25+0.217)2 + 0.2802 + 0.5772 + 1.2412 + 0.0602 + 0.02 + 0.202
+ 0.52] 1/2 NON COTerror = 7.514 % Narrow Range Level The Allowable Value (AV) for an increasing trip based on the requirements of Methods 1 or 2 as described in ISA-RP67.04.02-2000 (Ref. 5.43) is determined by subtracting the total NON-COT error from the Analytical Limit as shown below.
AV = 100.0 % - 7.514 %
AV = 92.486 % Narrow Range Level Step 3 - Determine the Nominal Trip Setpoint (NTSP)
As determined in Step 1, the Limiting Trip Setpoint is equal to 92.077 % Narrow Range Level. The current Nominal Trip Setpoint for this function at Kewaunee is 66.5 % Narrow Range Level. The Nominal Trip Setpoint is conservative with respect to the Limiting Trip Setpoint. The nominal operating band for Steam Generator Level at 100 % power is 44.0 % Level + 5.0 % Level (Refs. 5.134 and 5.135). Subtracting the worst case normal operating level of 49.0 % from the Nominal Trip Setpoint of 66.5 % yields an operating margin of 17.5 % level. This operating margin encompasses the entire Total Loop Uncertainty and should allow for stable operation. Therefore, the current Nominal Trip Setpoint of 66.5 % Narrow Range Level will be retained.
EE-0116 Page 44 of 205 Revision 7 Step 4 - Determine the As Found Tolerance (AFT)
As determined in Step 2, the Allowable Value (AV) is equal to 92.486 % Narrow Range Level. The As Found Tolerance will be based on the COT error components taken from Calculation C11116 (Ref. 5.97) as shown below.
The As Found Tolerance is equal to the Nominal Trip Setpoint plus the COT loop error components taken from the Total Loop Uncertainty (TLU) calculation. The COT loop error components from CSA Calculation C11116 are detailed below:
Module 1 - Foxboro or NUS Loop Power Supply (M1) = + 0.00 % of span Module 3 - Foxboro or NUS Bistable Module (M3) = + 0.50 % of span Rack Drift (RD) = + 1.0 % of span Combining the COT loop error components using the Square Root of the Sum of the Squares (SRSS) method as described in Dominion Standard STD-EEN-0304 (Ref. 5.5), we have the following COT total error:
COTerror = + (M12 + M32 + RD2) 1/2 COTerror = + (0.02 + 0.52 + 1.02) 1/2 COTerror = + 1.12 % Narrow Range Level As described in Step 4 above, the As Found Tolerance (AFT) for an increasing trip is determined by adding the total COT error to the Nominal Trip Setpoint as shown below.
AFT = 66.5 % + 1.12 % = 67.62 % Narrow Range Level This As Found Tolerance of 67.62 % Narrow Range Level will be included in the Setpoint Control Program to support Kewaunees conversion to ITS, noting the Nominal Trip Setpoint is equal to 66.5 %
Narrow Range Level. The Nominal Trip Setpoint and the As Found Tolerance are both set below the Allowable Value of 92.486 % Narrow Range Level and the Limiting Trip Setpoint of 92.077 % Narrow Range Level.
As Found Tolerance (AFT) = 66.5 % Narrow Range Level + 1.12 % Narrow Range Level As Left Tolerance (ALT) = 66.5 % Narrow Range Level + 0.50 % Narrow Range Level(1)
Steps 1 through 4 as they apply for Kewaunees Steam Generator High-High Water Level Reactor Trip are illustrated below in Figure 3.5-2.
(1) ALT = COT error minus Rack Drift (RD) = + (0.02 + 0.52) 1/2 = + 0.5 % of span = + 0.5 % NR Level
EE-0116 Page 45 of 205 Revision 7 KEWAUNEE'S STEAM GENERATOR HI-HI WATER LEVEL ESFAS Analytical Limit (AL) 100.00 NR Level TOTAL LOOP NON-COT ERRORS 7.514 % NR Level 7.923 % NR Level UNCERTAINTY (TLU)
Allowable Value (AV) 92.486 % NR Level COT ERRORS 0.409 % NR Level Limiting Trip Setpoint (LTSP) 92.077 % NR Level As Found Tolerance (AFT)
SAFETY MARGIN 67.62. % NR Level COT ERRORS 1.12 % NR 25.58 % NR Level Level Nominal Trip Setpoint (NTSP) 66.50 % NR Level OPERATING MARGIN 17.50 % NR Level High Operating Limit 49.00 % NR Level Nominal Operating Setpoint 44.00 % NR Level Figure 3.5-2 In addition to the above, TSTF-493, Revision 4 and RIS 2006-17 also stipulate that the As Left Tolerance be specified as part of the Setpoint Control Program. The As Left Tolerances will be specified for Kewaunees RPS instrumentation, ESFAS instrumentation, and other instrumentation associated with LCOs 3.3.5, 3.3.6, and 3.3.7 in Sections 4.5, 4.6, and 4.7, respectively. In general, for single input parameters, the As Left Tolerance will be equal to the calibration accuracy of the module or the SRSS of calibration accuracies of the modules used to develop the trip function. For multiple input parameters, the As Left Tolerance will be developed as described in Sections 4.5, 4.6, and 4.7.
EE-0116 Page 46 of 205 Revision 7 4.0 RESULTS 4.1 Allowable Values for North Anna ITS Table 3.3.1-1 (RTS Instrumentation)
Reactor Trips 4.1.1 Manual Reactor Trip Allowable Value = N/A (Ref. 5.8)
There is no specific RTS Trip Setpoint associated with this function.
4.1.2 Power Range Neutron Flux High Setpoint Reactor Trip Allowable Value : < 110.0 % RTP (Refs. 5.1, 5.8, 5.15 & 5.46)
Subtracting the Total Loop Uncertainty (TLU) from the Analytical Limit (AL) yields a Maximum Trip Setpoint (MTS) of 111.702 % Rated Thermal Power (RTP). Subtracting the NON COT error components from the Analytical Limit yields a Maximum Allowable Value (MAV) of 112.113 % RTP.
The Actual Nominal Trip Setpoint of 109.0 % RTP is conservative with respect to the Maximum Trip Setpoint and the Actual Allowable Value of 110.0 % RTP is conservative with respect to the Maximum Allowable Value. This Allowable Value of < 110.0 % RTP is based on maintaining a Nominal Trip Setpoint value of 109.0 % RTP.
The statistical combination of the COT and NON COT error components from CSA Calculation EE-0063 (Ref. 5.15) are given below. The COT and NON COT error components are used in Figure 4.1.2 to determine the Maximum Trip Setpoint (MTS) and the Maximum Allowable Value (MAV).
NON COTerror = SE + (PMA12 + PMA22 + PMA32 + M1MTE2 + M5MTE2 + RTE2) 1/2 NON COTerror = 0.0 + (1.6672 + 4.1672 + 1.6672 + 0.1102 + 0.9432 + 0.52) 1/2 NON COTerror = + 4.906 % of span = + 5.887 % RTP COTerror = + (M12 + M52 + RD2) 1/2 COTerror = + (0.12 + 0.8332 + 1.02) 1/2 COTerror = + 1.305 % of span = + 1.566 % RTP See Figure 4.1.2 for specific details.
EE-0116 Page 47 of 205 Revision 7 NORTH ANNA'S POWER RANGE NEUTRON FLUX HIGH REACTOR TRIP Analytical Limit (AL) 118.00 % RTP NON-COT ERRORS 5.887 % RTP TOTAL LOOP 6.298 % RTP UNCERTAINTY (TLU)
Maximum Allowable Value (MAV) 112.113 % RTP COT ERRORS 0.411 % RTP Maximum Trip Setpoint (MTS) 111.702 % RTP Actual Allowable Value (AV) 110.00 % RTP COT ERRORS SAFETY MARGIN 1.000 % RTP 2.702 % RTP Actual Trip Setpoint (ATS) 109.00 % RTP OPERATING MARGIN 7.00 % RTP High Operating Limit 102.00 % RTP Nominal Operating Setpoint 100.00 % RTP Figure 4.1.2 4.1.3 Power Range Neutron Flux Low Setpoint Reactor Trip Allowable Value : < 26.0 % RTP (Refs. 5.1, 5.8, 5.15 & 5.46)
Subtracting the Total Loop Uncertainty (TLU) from the Analytical Limit (AL) yields a Maximum Trip Setpoint (MTS) of 28.702 % Rated Thermal Power (RTP). Subtracting the NON COT error components from the Analytical Limit yields a Maximum Allowable Value (MAV) of 29.113 % RTP.
The Actual Nominal Trip Setpoint of 25.0 % RTP is conservative with respect to the Maximum Trip Setpoint and the Actual Allowable Value of 26.0 % RTP is conservative with respect to the Maximum Allowable Value. This Allowable Value of < 26.0 % RTP is based on maintaining a Nominal Trip Setpoint value of 25.0 % RTP.
The statistical combination of the COT and NON COT error components from CSA Calculation EE-0063 (Ref. 5.15) are given below. The COT and NON COT error components are used in Figure 4.1.3 to determine the Maximum Trip Setpoint (MTS) and the Maximum Allowable Value (MAV).
NON COTerror = SE + (PMA12 + PMA22 + PMA32 + M1MTE2 + M6MTE2 + RTE2) 1/2 NON COTerror = 0.0 + (1.6672 + 4.1672 + 1.6672 + 0.1102 + 0.9432 + 0.52) 1/2
EE-0116 Page 48 of 205 Revision 7 NON COTerror = + 4.906 % of span = + 5.887 % RTP COTerror = + (M12 + M62 + RD2) 1/2 COTerror = + (0.12 + 0.8332 + 1.02) 1/2 COTerror = + 1.305 % of span = + 1.566 % RTP See Figure 4.1.3 for specific details.
NORTH ANNA'S POWER RANGE NEUTRON FLUX LOW SETPOINT REACTOR TRIP Analytical Limit (AL) 35.00 % RTP COT ERRORS NON-COT ERRORS 5.887 % RTP TOTAL LOOP 6.298 % RTP Maximum Allowable Value (MAV)
UNCERTAINTY (TLU) 29.113 % RTP 0.411 % RTP Maximum Trip Setpoint (MTS) 28.702 % RTP Actual Allowable Value (AV) 26.00 % RTP COT ERRORS SAFETY MARGIN 1.000 % RTP 3.702 % RTP Actual Trip Setpoint (ATS) 25.00 % RTP OPERATING MARGIN 14.00 % RTP High Operating Limit 11.00 % RTP Nominal Operating Setpoint 10.00 % RTP Figure 4.1.3
EE-0116 Page 49 of 205 Revision 7 4.1.4 Power Range Neutron Flux High Positive Rate Reactor Trip Allowable Value : < 5.5 % RTP @ > 2 Seconds (Refs. 5.1, 5.8 & 5.46)
This Allowable Value of < 5.5 % RTP @ > 2.0 Seconds is based on maintaining a Nominal Trip Setpoint value of 5.0 % RTP @ 2.25 Seconds. The distance in percent of span between the Nominal Trip Setpoint and the Allowable Value is based on the time constant tolerance of + 10.0 % for the NIS Rate Lag Derivative Amplifier. This Allowable Value is calculated based on the dynamics involved with the trip and does not conform to the static methodologies described in Section 3.0.
Note : This trip function is not credited in the UFSAR Chapter 15 Safety Analysis. A CSA Calculation has not been performed for this function.
4.1.5 Power Range Neutron Flux High Negative Rate Reactor Trip Allowable Value : < 5.5 % RTP @ > 2 Seconds (Refs. 5.1, 5.8 & 5.46)
This Allowable Value of < 5.5 % RTP @ > 2.0 Seconds is based on maintaining a Nominal Trip Setpoint value of (-) 5.0 % RTP @ 2.25 Seconds. The distance in percent of span between the Nominal Trip Setpoint and the Allowable Value is based on the time constant tolerance of + 10.0 % for the NIS Rate Lag Derivative Amplifier. This Allowable Value is calculated based on the dynamics involved with the trip and does not conform to the static methodologies described in Section 3.0.
Note : This trip function is not credited in the UFSAR Chapter 15 Safety Analysis. A CSA Calculation has not been performed for this function.
4.1.6 Intermediate Range Neutron Flux High Reactor Trip Allowable Value : < 40.0 % RTP (Refs. 5.1, 5.8, 5.16 & 5.57)
Subtracting the Total Loop Uncertainty (TLU) from the Analytical Limit (AL) yields a Maximum Trip Setpoint (MTS) of 85.66 % Rated Thermal Power (RTP). Subtracting the NON COT error components from the Analytical Limit yields a Maximum Allowable Value (MAV) of 88.217 % RTP. The Actual Nominal Trip Setpoint of 35.0 % RTP is conservative with respect to the Maximum Trip Setpoint and the Actual Allowable Value of 40.0 % RTP is conservative with respect to the Maximum Allowable Value. This Allowable Value of < 40.0 % RTP is based on maintaining a Nominal Trip Setpoint value of 35.0 % RTP. See Figure 4.1.6 for specific details.
The statistical combination of the COT and NON COT error components from CSA Calculation EE-0738 (Ref. 5.16) are given below. The COT and NON COT error components are used in Figure 4.1.6 to determine the Maximum Trip Setpoint (MTS) and the Maximum Allowable Value (MAV).
NON COTerror = SE + (EA2 + PMA2 + PEA2 + SCA2 + SD2 + SPE2 + M4MTE2 + RTE2 + RRA2) 1/2 NON COTerror = 0.0 + (0.02 + 8.52 + 0.02 + 0.52 + 1.02 + 0.02 + 4.6542 + 0.52 + 1.02)1/2
EE-0116 Page 50 of 205 Revision 7 NON COTerror = + 9.819 % of span = + 11.783 % RTP COTerror = + (M42 + RD2) 1/2 COTerror = + (3.5302 + 1.02) 1/2 COTerror = + 3.669 % of span = + 4.403 % RTP See Figure 4.1.6 for specific details.
NORTH ANNA'S INTERMEDIATE RANGE HIGH FLUX REACTOR TRIP Analytical Limit (AL) 100.00 % RTP COT ERRORS NON-COT ERRORS TOTAL LOOP 11.783 % RTP 14.34 % RTP Maximum Allowable Value (MAV)
UNCERTAINTY (TLU) 88.217 % RTP 2.557 % RTP Maximum Trip Setpoint (MTS) 85.66 % RTP Actual Allowable Value (AV) 40.00 % RTP COT ERRORS SAFETY MARGIN 5.000 % RTP 50.66 % RTP Actual Trip Setpoint (ATS) 35.00 % RTP OPERATING MARGIN 26.00 % RTP High Operating Limit 9.00 % RTP Nominal Operating Setpoint 8.00 % RTP Figure 4.1.6
EE-0116 Page 51 of 205 Revision 7 4.1.7 Source Range Neutron Flux High Reactor Trip Allowable Value : < 1.3
- 105 CPS (Refs. 5.1, 5.8, 5.17 & 5.51)
Subtracting the Total Loop Uncertainty (TLU = + 0.84
- 105 and - 0.46
- 105 Counts Per Second (1). Subtracting the NON COT error components from the Analytical Limit yields a Maximum Allowable Value (MAV) of 2.36
- 105 Counts Per Second (CPS). The Actual Nominal Trip Setpoint of 1.0
- 105 CPS is conservative with respect to the Maximum Trip Setpoint and the Actual Allowable Value of 1.3
- 105 CPS is conservative with respect to the Maximum Allowable Value. The current Allowable Value of 1.3
- 105 CPS is more conservative than the calculated COT error and will be retained.
The statistical combination of the COT and NON COT error components from CSA Calculation EE-0710 (Ref. 5.17) are given below. The COT and NON COT error components are used in Figure 4.1.7 to determine the Maximum Trip Setpoint (MTS) and the Maximum Allowable Value (MAV).
NON COTerror = SE + [PMA2 + PEA2 + (SCA+SMTE)2 + SD2 + SPE2 + SPSE2 + M1MTE2 + M2MTE2
+ RTE2 + RRA2]1/2 NON COTerror = 0.0 + [0.02 + 0.02 + (0.0+0.0)2 + 0.02 + 0.02 + 0.02 + 1.0652 + 1.02 + 0.52 + 0.02]1/2 NON COTerror = + 1.554 % of linear span
= + 0.24*105 CPS and - 0.19*105 CPS (Based on the Nominal Trip setpoint of 1.0*105 CPS)
= 0.24*105 CPS (2)
COTerror = + (M12 + M22 + RD2) 1/2 COTerror = + (1.6172 + 1.92 + 1.92) 1/2 COTerror = + 3.136 % of linear span
= + 0.54*105 CPS and - 0.35*105 CPS (Based on the Nominal Trip Setpoint of 1.0*105 CPS)
= 0.35*105 CPS (2)
(1) Nominal Trip Setpoint = 1.0
- 105 CPS log 1.0
- 105 = 5.0 (on a 0 to 6 Decade scale)
Analytical Limit = 2.6
- 105 CPS log 2.6
- 105 = 5.41497 (on a 0 to 6 Decade scale)
Full CSA = + 4.412 % of linear span (4.412 %/100 %)
- 6 Decades = + 0.26472 Decade High Trip Setpoint = 5.0 + 0.26472 = 5.26472 antilog 5.26472 = 1.84
- 105 Low Trip Setpoint = 5.0 - 0.26472 = 4.73528 antilog 4.73528 = 0.54
- 105 CSA(+) = 1.84
- 105 - 1.0
- 105 = 0.84
- 105 and CSA(-) = 1.0
- 105 - 0.54
- 105 = 0.46
- 105 Full CSA = (+) 0.84
- 105 CPS and (-) 0.46
- 105 CPS (2) The most conservative value is used regardless of sign.
EE-0116 Page 52 of 205 Revision 7 NORTH ANNA'S SOURCE RANGE NEUTRON FLUX HIGH REACTOR TRIP Analytical Limit (AL) 2.60
- 105 CPS 0.84
- 105 CPS Maximum Allowable Value (MAV)
UNCERTAINTY (TLU) 2.36
- 105 CPS 0.60
- 105 CPS COT ERRORS SAFETY MARGIN 0.3
- 105 CPS 0.76
- 105 CPS OPERATING MARGIN 2.30
- 104 CPS High Operating Limit 7.70
- 104 CPS Nominal Operating Limit 3.90
- 104 CPS Figure 4.1.7
EE-0116 Page 53 of 205 Revision 7 4.1.8 Overtemperature T Reactor Trip Allowable Value : See below (Refs. 5.1, 5.8, 5.18 & 5.47)
" The channel's maximum Trip Setpoint shall not exceed its computed Trip Setpoint by more than 2.0 % of the T span " (Note that 2.0 % of the T span is equal to 3.0 % T Power)
The Overtemperature T (OTT) Reactor Trip Setpoint is variable and is constantly calculated based on actual plant conditions. For this reason, the Allowable Value cannot be expressed as a constant.
Further, the OTT Reactor Trip will be analyzed for the following three conditions:
- OTT Reactor Trip with no FI
- OTT Reactor Trip with (+) FI
- OTT Reactor Trip with (-) FI Note: FI is the Delta Flux Penalty generated from the Upper and Lower Power Range Neutron Flux Detectors (i.e., QU and QL).
Subtracting the Total Loop Uncertainty (TLU) from the Analytical Limit (AL) yields the following Maximum Trip Setpoints (MTS) for the three OTT Reactor Trip conditions described above:
- MTS for OTT Reactor Trip with no FI = 139.0 % - 6.716 % = 132.28 % T Power
- MTS for OTT Reactor Trip with (+) FI = 145.0 % - 9.005 % = 135.99 % T Power
- MTS for OTT Reactor Trip with (-) FI = 144.0 % - 8.378 % = 135.62 % T Power Subtracting the NON COT error components from the Analytical Limit yields the following Maximum Allowable Values (MAV) for the three OTT Reactor Trip conditions described above:
- MAV for OTT Reactor Trip with no FI = 139.0 % - 5.214 % = 133.79 % T Power
- MAV for OTT Reactor Trip with (+) FI = 145.0 % - 7.949 % = 137.05 % T Power
- MAV for OTT Reactor Trip with (-) FI = 144.0 % - 7.230 % = 136.77 % T Power For the most limiting condition (i.e., OTT Reactor Trip with no FI) the Actual Nominal Trip Setpoint of 126.4 % T Power (e.g., based on TAVG = 586.8 oF) is conservative with respect to the Maximum Trip Setpoint of 132.28 % T Power and the Actual Allowable Value of 129.4 % T Power is conservative with respect to the Maximum Allowable Value of 133.79 % T Power. This Allowable Value of < 129.4 % T Power is based on maintaining a Nominal Trip Setpoint value of 126.4 % T Power. Note that this analysis is based on static conditions such that dynamic components are not considered.
The statistical combination of the COT and NON COT error components from CSA Calculation EE-0434 (Ref. 5.18) with the appropriate modifications described in Section 3.2 for the OTT Reactor Trip are given below. The COT and NON COT error components are used in Figure 4.1.8 to determine the Maximum Trip Setpoint (MTS) and the Maximum Allowable Value (MAV) for the most limiting condition.
EE-0116 Page 54 of 205 Revision 7 OTT Reactor Trip with no FI NON COTerror = [EAnon2 + PMATAVG2 + PMAT2 + PEA2 + (SCARTD +SMTERTD)2 + (SCARTD
+SMTERTD)2 + (SCARTD +SMTERTD)2 + (SCARTD +SMTERTD)2 + (4
- SDRTD2) + STERTD2 + PMAXMTR2
+ (SCAXMTR +SMTEXMTR)2 + SDXMTR2 + STEXMTR2 + FLUX12 + RMTE12 + RMTE22 + RMTE32 +
RMTE42 + RMTE52 + RMTE62 + RTE2]1/2 Where the following RMTE Terms are taken from Calculation EE-0434 (Ref. 5.18) :
RMTE1 = T Channel Measuring and Test Equipment = (M1MTE2 + M2MTE2 + M3MTE2 + M4MTE2
+ M5MTE2 + M6MTE2 + M15MTE2) 1/2 RMTE1 = (0.232 + 0.232 + 0.232 + 0.232 + 0.122 + 0.092 + 0.062) 1/2 = 0.488 % of span RMTE2 = TAVG Channel Measuring and Test Equipment = (M1MTE2 + M2MTE2 + M3MTE2 +
M4MTE2 + M5MTE2 + M7MTE2 + M20MTE2 + M35MTE2) 1/2 RMTE2 = (0.232 + 0.232 + 0.232 + 0.232 + 0.122 + 0.092 + 0.062 + 0.062)1/2 = 0.491 % of span RMTE3 = Pressurizer Pressure Channel Measuring and Test Equipment = (M36MTE2 + M37MTE2)1/2 RMTE3 = (0.082 + 0.062)1/2 = 0.100 % of span RMTE4 = FI Channel Measuring and Test Equipment = (M38MTE2 + M39MTE2 + M40MTE2 +
M41MTE2) 1/2 RMTE4 = (0.062 + 0.062 + 0.092 + 0.062) 1/2 = 0.137 % of span RMTE5 = OTT Setpoint Summator Measuring and Test Equipment = M42MTE RMTE5 = 0.120 % of span RMTE6 = OTT Reactor Trip Bistable Measuring and Test Equipment = M47MTE RMTE6 = 0.060 % of span Thus, the NON COTerror is equal to:
NON COTerror = [0.002 + 1.702 + 1.302 + 0.002 + (0.417+0.167)2 + (0.417+0.167)2 + (0.417+0.167)2 +
(0.417+0.167)2 + (4
- 0.252) + 0.002 + 0.002 + (0.50+0.425)2 + 0.452 + 2.0132 + 0.002 + 0.4882 + 0.4912
+ 0.1002 + 0.1372 + 0.1202 + 0.0602 + 0.5002]1/2 NON COTerror = + 3.476 % of span = + 5.214 % T Power COTerror = + (RCA12 + RCA22 + RCA32 +RCA42 + RCA52 + RCA62 + RDTAVG2 + RDT2) 1/2
EE-0116 Page 55 of 205 Revision 7 COTerror = + (0.52 + 0.52 + 0.52 + 0.52 + 0.52 + 0.52 + 1.02 + 1.02) 1/2 COTerror = + 1.871 % of span = + 2.806 % T Power OTT Reactor Trip with (+) FI NON COTerror = ]EAnon2 + PMATAVG2 + PMAT2 + PEA2 + (SCARTD +SMTERTD)2 + (SCARTD
+SMTERTD)2 + (SCARTD +SMTERTD)2 + (SCARTD +SMTERTD)2 + (4
- SDRTD2) + STERTD2 + PMAXMTR2
+ (SCAXMTR +SMTEXMTR)2 + SDXMTR2 + STEXMTR2 + FLUX22 + RMTE12 + RMTE22 + RMTE32 +
RMTE42 + RMTE52 + RMTE62 + RTE2]1/2 NON COTerror = [0.002 + 1.702 + 1.302 + 0.002 + (0.417+0.167)2 + (0.417+0.167)2 + (0.417+0.167)2 +
(0.417+0.167)2 + (4
- 0.252) + 0.002 + 0.002 + (0.50+0.425)2 + 0.452 + 2.0132 + 4.002 + 0.4882 + 0.4912
+ 0.1002 + 0.1372 + 0.1202 + 0.0602 +0.5002]1/2 NON COTerror = + 5.299 % of span = + 7.949 % T Power COTerror = + (RCA12 + RCA22 + RCA32 +RCA42 + RCA52 + RCA62 + RDTAVG2 + RDT2) 1/2 COTerror = + (0.52 + 0.52 + 0.52 + 0.52 + 0.52 + 0.52 + 1.02 + 1.02) 1/2 COTerror = + 1.871 % of span = + 2.806 % T Power OTT Reactor Trip with (-) FI NON COTerror = [EAnon2 + PMATAVG2 + PMAT2 + PEA2 + (SCARTD +SMTERTD)2 + (SCARTD
+SMTERTD)2 + (SCARTD +SMTERTD)2 + (SCARTD +SMTERTD)2 + (4
- SDRTD2) + STERTD2 + PMAXMTR2
+ (SCAXMTR +SMTEXMTR)2 + SDXMTR2 + STEXMTR2 + FLUX22 + RMTE12 + RMTE22 + RMTE32 +
RMTE42 + RMTE52 + RMTE62 + RTE2]1/2 NON COTerror = [0.002 + 1.702 + 1.302 + 0.002 + (0.417+0.167)2 + (0.417+0.167)2 + (0.417+0.167)2 +
(0.417+0.167)2 + (4
- 0.252) + 0.002 + 0.002 + (0.50+0.425)2 + 0.452 + 2.0132 + 3.342 + 0.4882 + 0.4912
+ 0.1002 + 0.1372 + 0.1202 + 0.0602 + 0.5002]1/2 NON COTerror = + 4.820 % of span = + 7.230 % T Power COTerror = + (RCA12 + RCA22 + RCA32 +RCA42 + RCA52 + RCA62 + RDTAVG2 + RDT2) 1/2 COTerror = + (0.52 + 0.52 + 0.52 + 0.52 + 0.52 + 0.52 + 1.02 + 1.02) 1/2 COTerror = + 1.871 % of span = + 2.806 % T Power See Figure 4.1.8 for specific details associated with the OTT Reactor Trip with no FI.
EE-0116 Page 56 of 205 Revision 7 NORTH ANNA'S OVERTEMPERATURE DELTA T REACTOR TRIP Analytical Limit (AL) 139.00 % Delta T Power NON-COT ERRORS 1.502 % DT PWR 5.214 % DT PWR TOTAL LOOP 6.716 % DT Power Maximum Allowable Value (MAV)
UNCERTAINTY (TLU) 133.79 % Delta T Power COT ERRORS Maximum Trip Setpoint (MTS) 132.28 % Delta T Power Actual Allowable Value (AV)
SAFETY MARGIN 129.40 % Delta T Power COT ERRORS 3.0 % DT PWR 5.88 % DELTA T POWER Actual Trip Setpoint (ATS) 126.40 % Delta T Power OPERATING MARGIN 23.40 % DELTA T POWER High Operating Limit 103.00 % Delta T Power Nominal Operating Limit 100.00 % Delta T Power Figure 4.1.8
EE-0116 Page 57 of 205 Revision 7 4.1.9 Overpower T Reactor Trip Allowable Value : See below (Refs. 5.1, 5.8, 5.18 & 5.47)
" The channel's maximum Trip Setpoint shall not exceed its computed Trip Setpoint by more than 2.0 % of the T span " (Note that 2.0 % of the T span is equal to 3.0 % T Power)
The Overpower T Reactor Trip Setpoint is variable and is constantly calculated based on actual plant conditions. For this reason, the Allowable Value cannot be expressed as a constant. The Overpower T Reactor Trip is a backup reactor trip function and is not credited in the UFSAR Chapter 15 Safety Analysis. The Allowable Value of 2.0 % of the T span is consistent with the original design basis for this function and is conservative with respect to the CSA Calculation assumptions (Ref. 5.18).
4.1.10 Pressurizer Low Pressure Reactor Trip Allowable Value : > 1860 PSIG (Refs. 5.1, 5.8, 5.19 & 5.44)
Adding the Total Loop Uncertainty (TLU) to the Analytical Limit (AL) yields a Minimum Trip Setpoint (MTS) of 1851.58 PSIG. Adding the NON COT error components to the Analytical Limit yields a Minimum Allowable Value (MAV) of 1849.41 PSIG. The Actual Nominal Trip Setpoint of 1870 PSIG is conservative with respect to the Minimum Trip Setpoint and the Actual Allowable Value of 1860 PSIG is conservative with respect to the Minimum Allowable Value. This Allowable Value of > 1860 PSIG is based on maintaining a Nominal Trip Setpoint value of 1870 PSIG.
In this case, the current Allowable Value of > 1860 PSIG will be retained because it is sufficiently close enough to the calculated value using the CSA rack error terms from Calculation EE-0069 (Ref 5.19).
The calculated Allowable Value for this function is > 1860.8 PSIG. The 0.8 PSIG offset is accommodated in the 18.42 PSIG Safety Margin for this trip as illustrated in Figure 4.1.10.
The statistical combination of the COT and NON COT error components from CSA Calculation EE-0069 (Ref. 5.19) are given below. The COT and NON COT error components are used in Figure 4.1.10 to determine the Minimum Trip Setpoint (MTS) and the Minimum Allowable Value (MAV).
NON COTerror = SE + [EA2 + (SCA+SMTE)2 + SD2 + SPE2 + STE2 + M1MTE2 + M2MTE2 +
RCSAMTE2 + RTE2] 1/2 NON COTerror = 0.0 + [0.02 + (0.500+0.404)2 + 0.752 + 0.02 + 2.0132 + 0.1532 + 0.02 + 0.032 + 0.52] 1/2 NON COTerror = + 2.389 % of span = + 19.11 PSIG COTerror = + (M12 + M22 + RCSA2 + RD2) 1/2 COTerror = + (0.12 + 0.52 + 0.252 + 1.02) 1/2 COTerror = + 1.150 % of span = + 9.2 PSIG
EE-0116 Page 58 of 205 Revision 7 See Figure 4.1.10 for specific details.
NORTH ANNA'S PRESSURIZER LOW PRESSURE REACTOR TRIP Nominal Operating Limit 2235 PSIG Low Operating Limit 2210 PSIG OPERATING MARGIN 340 PSIG (Static)
Actual Trip Setpoint (ATS) 1870 PSIG COT ERRORS 10.0 PSIG SAFETY MARGIN 18.42 PSIG (Static)
Actual Allowable Value (AV) 1860 PSIG Minimum Trip Setpoint (MTS) 1851.58 PSIG COT ERRORS 2.17 PSIG TOTAL LOOP 21.28 PSIG Minimum Allowable Value (MAV) 1849.41 PSIG UNCERTAINTY (TLU)
NON-COT ERRORS 19.11 PSIG Analytical Limit (AL) 1830.3 PSIG Figure 4.1.10
EE-0116 Page 59 of 205 Revision 7 4.1.11 Pressurizer High Pressure Reactor Trip Allowable Value : < 2370 PSIG (Refs. 5.1, 5.8, 5.19, 5.44 & 5.88)
Subtracting the Total Loop Uncertainty (TLU) from the Analytical Limit (AL) yields a Maximum Trip Setpoint (MTS) of 2370.4 PSIG. Subtracting the NON COT error components from the Analytical Limit yields a Maximum Allowable Value (MAV) of 2372.19 PSIG. The Actual Nominal Trip Setpoint of 2360 PSIG is conservative with respect to the Maximum Trip Setpoint. The current Actual Allowable Value of 2370 PSIG is conservative with respect to the Maximum Allowable Value. The Nominal Trip Setpoint value of 2360 PSIG allows a 10 PSIG margin to be used for the COT error components. This leaves a margin of 2.19 PSIG from the Actual Allowable Value to the Maximum Allowable Value as illustrated in Figure 4.1.11.
The statistical combination of the COT and NON COT error components from CSA Calculation EE-0069 (Ref. 5.19) are given below. The COT and NON COT error components are used in Figure 4.1.11 to determine the Maximum Trip Setpoint (MTS) and the Maximum Allowable Value (MAV).
NON COTerror = SE + [EA2 + (SCA+SMTE)2 + SD2 + SPE2 + STE2 + M1MTE2 + M2MTE2 +
RCSAMTE2 + RTE2] 1/2 NON COTerror = 0.0 + [0.02 + (0.500+0.404)2 + 0.752 + 0.02 + 2.0132 + 0.1532 + 0.02 + 0.032 + 0.52] 1/2 NON COTerror = + 2.389 % of span = + 19.11 PSIG COTerror = + (M12 + M22 + RD2) 1/2 COTerror = + (0.12 + 0.252 + 1.02) 1/2 COTerror = + 1.036 % of span = + 8.29 PSIG See Figure 4.1.11 for specific details.
EE-0116 Page 60 of 205 Revision 7 NORTH ANNA'S PRESSURIZER HIGH PRESSURE REACTOR TRIP Analytical Limit (AL) 2391.3 PSIG NON-COT ERRORS 19.11 PSIG TOTAL LOOP 20.9 PSIG Maximum Allowable Value (MAV)
UNCERTAINTY (TLU) 2372.19 PSIG COT ERRORS 1.79 PSIG Maximum Trip Setpoint (MTS) 2370.4 PSIG Actual Allowable Value (AV) 2370.0 PSIG COT ERRORS SAFETY MARGIN 10.0 PSIG 10.4 PSIG Actual Trip Setpoint (ATS) 2360.0 PSIG OPERATING MARGIN 100.0 PSIG High Operating Limit 2260.0 PSIG Nominal Operating Limit 2235.0 PSIG Figure 4.1.11 4.1.12 Pressurizer High Level Reactor Trip Allowable Value : < 93.0 % Level (Hot) (Refs. 5.1, 5.8, 5.20 & 5.54)
The analysis for North Annas Pressurizer High Level Reactor Trip was performed in Section 3.4.3 and the specific details are illustrated in Figure 3.4.3.a.
EE-0116 Page 61 of 205 Revision 7 4.1.13 Reactor Coolant Flow Low Reactor Trip Allowable Value : > 89.0 % Flow (Normalized) (Refs. 5.1, 5.8, 5.21, 5.53 & 5.84)
Adding the Total Loop Uncertainty (TLU) to the Analytical Limit (AL) yields a Minimum Trip Setpoint (MTS) of 89.338 % Flow. Adding the NON COT error components to the Analytical Limit yields a Minimum Allowable Value (MAV) of 88.986 % Flow. The current Nominal Trip Setpoint of 90.0 %
Flow is conservative with respect to the Minimum Trip Setpoint. The current Allowable Value of >
89.0 % Flow is conservative with respect to the Minimum Allowable Value. The Nominal Trip Setpoint value of 90.0 % Flow will allow a 1.0 % Flow margin to be used for the COT error components. The Allowable Value of > 89.0 % Flow is conservative with respect to the calculated value using the CSA rack error terms from Calculation EE-0060 (Ref 5.21).
The statistical combination of the COT and NON COT error components from CSA Calculation EE-0060 (Ref. 5.21) are given below. The COT and NON COT error components are used in Figure 4.1.13 to determine the Minimum Trip Setpoint (MTS) and the Minimum Allowable Value (MAV).
NON COTerror (P span) = [(SCA+SMTE)2 + SD2 + SPE2 + STE2 + M1MTE2 + M2MTE2] 1/2 NON COTerror (P span) = [(0.000 + 0.000)2 + 0.3752 + 0.02 + 0.0002 + 0.1532 + 0.0302]1/2 NON COTerror (P span) = + 0.406 % of P span = + 0.271 % of Flow span @ 90 % Flow(1)
NON COTerror (Flow span) = (PMA2 + PEA2 + RTE2) 1/2 NON COTerror (Flow span) = (1.5122 + 0.3602 + 0.52) 1/2 NON COTerror (Flow span) = 1.633 % of Flow span TOTAL NON COTerror (Flow span) = (1.6332 + 0.2712) 1/2 = 1.655 % of Flow span = 1.986 % Flow @
90.0 % Flow(2).
COTerror (P span ) = + (M12 + M22) 1/2 COTerror (P span ) = + (0.12 + 0.252) 1/2 COTerror (P span) = + 0.269 % of P span = + 0.179 % of Flow span @ 90 % Flow COTerror (Flow span) = RD = 1.0 % of Flow span TOTAL COTerror (Flow span) = (0.1792 + 1.02) 1/2 = 1.016 % of Flow span = 1.219 % Flow @ 90.0 %
Flow.
(1) % Flow Span = (P uncertainty)
- 0.5 * (Flowmax/Flownom) 0.271 = (0.406)*0.5*(120/90) (Refs. 5.23 and 5.120)
EE-0116 Page 62 of 205 Revision 7 (2) % Flow = (% Flow Span / 100)
- 120 See Figure 4.1.13 for specific details.
NORTH ANNA'S LOW REACTOR COOLANT FLOW REACTOR TRIP Nominal Operating Limit 100 % Flow Low Operating Limit 98.0 % Flow OPERATING MARGIN 8.0 % Flow Actual Trip Setpoint (ATS) 90.0 % Flow COT ERRORS 1.0 % Flow SAFETY MARGIN 0.662 % Flow Minimum Trip Setpoint (MTS) 89.338 % Flow Actual Allowable Value (AV) 89.0 % Flow COT ERRORS 0.352 % Flow TOTAL LOOP Minimum Allowable Value (MAV) 2.338 % Flow 88.986 % Flow UNCERTAINTY (TLU)
NON-COT ERRORS 1.986 % Flow Analytical Limit (AL) 87.0 % Flow (1) The TLU is based on the 90% trip setpoint in CSA Calculation EE-0060 (Ref. 5.21)
Figure 4.1.13 4.1.14 Reactor Coolant Pump Breaker Position Allowable Value : N/A (Ref. 5.8)
There is no specific RTS Trip Setpoint associated with this function.
EE-0116 Page 63 of 205 Revision 7 4.1.15 Reactor Coolant Pump Undervoltage Allowable Value : This Allowable Value will be provided by Corporate Electrical EE Power.
4.1.16 Reactor Coolant Pump Underfrequency Allowable Value : This Allowable Value will be provided by Corporate Electrical EE Power.
4.1.17 Steam Generator Water Level Low Low Reactor Trip/SI Allowable Value : > 17.0 % Narrow Range (NR) Level (Refs. 5.1, 5.8, 5.22 & 5.48)
The analysis for Steam Generator Water Level Low Low Reactor Trip will be based on HARSH/DBE Conditions which will bound both the Reactor Trip and ESFAS Initiation Functions. Adding the Total Loop Uncertainty (TLU) to the Analytical Limit (AL) yields a Minimum Trip Setpoint (MTS) of 14.955
% NR Level. Adding the NON COT error components to the Analytical Limit yields a Minimum Allowable Value (MAV) of 14.645 % NR Level. The Actual Nominal Trip Setpoint of 18.0 % NR Level is conservative with respect to the Minimum Trip Setpoint and the Actual Allowable Value of >
17.0 % NR Level is conservative with respect to the Minimum Allowable Value. In this case, the current Allowable Value of > 17.0 % NR Level will be retained because it meets the requirements of Methods 1 and 2 as discussed in Sections 3.3.1 and 3.3.2. In addition, the current Allowable Value is conservative with respect to the calculated value using the CSA rack error terms from Calculation EE-0492 (Ref 5.22). This Allowable Value of > 17.0 % NR Level is based on maintaining a Nominal Trip Setpoint value of 18.0 % NR Level.
The statistical combination of the COT and NON COT error components from CSA Calculation EE-0492 (Ref. 5.22) are given below. The COT and NON COT error components are used in Figure 4.1.17 to determine the Minimum Trip Setpoint (MTS) and the Minimum Allowable Value (MAV).
NON COTerror = PMADBE + IR + SPTE + REDBE + ]PEA2 + (SCA+SMTE)2 + SD2 + SPE2 + STE2 +
M1MTE2 + M2MTE2 + RTE2] 1/2 NON COTerror = 8.4 + 0.960 +3.619 + 0.0 + [0.02 + (0.5+0.383)2 + 0.2892 + 0.6352 + 1.1102 + 0.1582 +
0.052 + 0.52]1/2 NON COTerror = + 14.645 % of span = + 14.645 % NR Level (worst case).
COTerror = + (M12 + M22 + RD2) 1/2 COTerror = + (0.12 + 0.252 + 1.02) 1/2 COTerror = + 1.036 % of span = + 1.036 % NR level See Figure 4.1.17 for specific details.
EE-0116 Page 64 of 205 Revision 7 NORTH ANNA'S STEAM GENERATOR LO-2 LEVEL REACTOR TRIP / ESFAS INITIATION Nominal Operating Limit 44.0 % NR Level Low Operating Limit 39.0 % NR Level OPERATING MARGIN 21.0 % NR Level Actual Trip Setpoint (ATS) 18.0 % NR Level COT ERRORS 1.0 % Flow SAFETY MARGIN 3.045 % NR Level Actual Allowable Value (AV) 17.0 % NR Level Minimum Trip Setpoint (MTS) 0.31 % NR Level 14.955 % NR Level COT ERRORS TOTAL LOOP 14.955 % NR Level Minimum Allowable Value (MAV) 14.645 % NR Level UNCERTAINTY (TLU)
NON-COT ERRORS 14.645 % NR Level Analytical Limit (AL) 0.0 % NR Level (DBE)
Figure 4.1.17 4.1.18 Steam Generator Water Level Low Coincident Reactor Trip Allowable Value : > 24.0 % Narrow Range (NR) Level (Refs. 5.1, 5.8, 5.22 & 5.48)
This Allowable Value of > 24.0 % NR Level is based on maintaining a Nominal Trip Setpoint value of 25.0 % Level. In this case, the current value of > 24.0 % NR Level will be retained because it is conservative with respect to the calculated value the CSA rack error terms from Calculation EE-0492 (Ref 5.22). The Steam Generator Water Level Low Coincident Reactor Trip is a backup reactor trip function and no specific setpoint is assumed.
EE-0116 Page 65 of 205 Revision 7 4.1.19 Steam Flow Feed Flow Mismatch Coincident Reactor Trip Allowable Value : < 42.5 % of Fnom (i.e., nominal Feedwater Flow at RTP)
(Refs. 5.1, 5.8, 5.23 & 5.49)
This Allowable Value of < 42.5 % of Fnom is based on maintaining a Nominal Trip Setpoint value of 40.0 % of Fnom. In this case, the current Allowable Value of < 42.5 % of Fnom will be retained because it is conservative with respect to the calculated value based on the CSA rack error terms from Calculation EE-0736 (Ref 5.23). The Steam Flow Feed Flow Mismatch Coincident Reactor Trip is a backup reactor trip function and is not credited in the UFSAR Chapter 15 Safety Analysis.
4.1.20 Turbine Trip - Low Auto Stop Oil Pressure Allowable Value : > 40.0 PSIG (Refs. 5.1, 5.8 & 5.45)
This Allowable Value of > 40.0 PSIG is based on maintaining a Nominal Trip Setpoint value of 45.0 PSIG. In this case, the current Allowable Value of > 40.0 PSIG will be retained because it is sufficiently close enough to the calculated value. The calculated Allowable Value is based on adding the uncertainty values associated with the pressure switch calibration accuracy and drift / repeatability (i.e.,
1.3 PSIG + 2.6 PSIG = 3.9 PSIG). In this case the current and historical Allowable Value of > 40.0 PSIG will be retained because this trip is not credited in the UFSAR Chapter 15 Safety Analysis and a CSA Calculation has not been performed for this function, thus no Safety or Design Basis analysis is adversely affected.
4.1.21 Turbine Stop Valve Closure Allowable Value : > 0.0 % Open (Refs. 5.1, 5.8 & 5.70)
The Turbine Stop Valve Closure function is not credited in the UFSAR Chapter 15 Safety Analysis and therefore no Safety Analysis Limit is specified in References 5.1 and 5.2 for this function. In addition, a CSA Calculation has not been performed for this function. The current Trip Setpoint at North Anna for the Turbine Stop Valve Closure function is > 1.0 % Open and the Allowable Value is > 0.0 % Open (Ref 5.2).
The basis for retaining the current Allowable Value for the Turbine Stop Valve Closure function is given below :
- 1. There is no Safety Analysis Limit or implied Design Basis Limit for this function that has been documented in Technical Specifications, UFSAR or the DBD. In addition, no CSA Calculation has been performed for this function at North Anna.
- 2. The proposed 1.0 % delta between the Trip Setpoint and the Allowable Value is consistent with North Anna's current values and has been used since the initial startup of the plant (Ref 5.3).
- 3. The proposed Allowable Value is also consistent with value given in the "Westinghouse Reactor Protection System / Engineered Safety Features Actuation System Setpoint Methodology provided to Dominion Virginia Power under S/N 541, Dockets 50-338 and 50-339 (Ref 5.3).
EE-0116 Page 66 of 205 Revision 7 4.1.22 Safety Injection (SI) Input from Engineered Safety Features Actuation System (ESFAS)
Allowable Value : N/A (Ref. 5.8)
There is no specific RTS Trip Setpoint associated with this function.
Reactor Trip Permissives 4.1.23 Permissive P-6, Intermediate Range Neutron Flux Allowable Value : > 3 *10-11 Amps (Refs. 5.1, 5.8, 5.16 & 5.57)
This Allowable Value of > 3 *10-11 Amps is based on maintaining a Nominal Trip Setpoint value of 5
- 10-11 Amps. In this case, the current Allowable Value of > 3 *10-11 Amps will be retained because it is equal to the calibration accuracy of the device. Note that this function is assumed to be available in the UFSAR Chapter 15 Safety Analysis but no specific setpoint is assumed (Refs 5.1 & 5.2).
4.1.24 Permissive P-7, Block Low Power Reactor Trips Allowable Value : N/A (Refs. 5.1 & 5.8)
Permissive P-7 is made up of Permissives P-10 and P-13.
4.1.25 Permissive P-8, Power Range Neutron Flux Allowable Value : < 31.0 % RTP (Refs. 5.1, 5.8, 5.15 & 5.46)
Subtracting the Total Loop Uncertainty (TLU) from the Analytical Limit (AL) yields a Maximum Trip Setpoint (MTS) of 33.702 % Rated Thermal Power (RTP). Subtracting the NON COT error components from the Analytical Limit yields a Maximum Allowable Value (MAV) of 34.113 % RTP.
The Actual Nominal Trip Setpoint of 30.0 % RTP is conservative with respect to the Maximum Trip Setpoint and the Actual Allowable Value of 31.0 % RTP is conservative with respect to the Maximum Allowable Value. This Allowable Value of < 31.0 % RTP is based on maintaining a Nominal Trip Setpoint value of 30.0 % RTP.
The statistical combination of the COT and NON COT error components from CSA Calculation EE-0063 (Ref. 5.15) are given below. The COT and NON COT error components are used in Figure 4.1.25 to determine the Maximum Trip Setpoint (MTS) and the Maximum Allowable Value (MAV).
NON COTerror = SE + (PMA12 + PMA22 + PMA32 + M1MTE2 + M7MTE2 + RTE2) 1/2 NON COTerror = 0.0 + (1.6672 + 4.1672 + 1.6672 +0.1102 + 0.9432 + 0.52) 1/2 NON COTerror = + 4.906 % of span = + 5.887 % RTP COTerror = + (M12 + M72 + RD2) 1/2
EE-0116 Page 67 of 205 Revision 7 COTerror = + (0.12 + 0.8332 + 1.02) 1/2 COTerror = + 1.305 % of span = + 1.566 % RTP See Figure 4.1.25 for specific details.
NORTH ANNA'S POWER RANGE REACTOR TRIP PERMISSIVE P-8 Analytical Limit (AL) 40.00 % RTP NON-COT ERRORS 5.887 % RTP TOTAL LOOP 6.298 % RTP Maximum Allowable Value (MAV)
UNCERTAINTY (TLU) 34.113 % RTP COT ERRORS 0.411 % RTP Maximum Trip Setpoint (MTS) 33.702 % RTP Actual Allowable Value (AV) 31.00 % RTP COT ERRORS SAFETY MARGIN 1.000 % RTP 3.702 % RTP Actual Trip Setpoint (ATS) 30.00 % RTP OPERATING MARGIN 19.00 % RTP High Operating Limit 11.00 % RTP Nominal Operating Setpoint 10.00 % RTP Figure 4.1.25
EE-0116 Page 68 of 205 Revision 7 4.1.26 Permissive P-10, Power Range Neutron Flux Allowable Values : > 7.0 % RTP AND (Refs. 5.1, 5.8, 5.15 & 5.46)
< 11.0 % RTP These Allowable Values of > 7.0 % RTP and < 11.0 % RTP are based on maintaining a Nominal Trip Setpoint value of 10.0 % RTP and a Nominal Reset value of 8.0 % RTP. In this case, the current Allowable Values will be retained because they are conservative with respect to the calculated values using the CSA rack error terms from Calculation EE-0063 (Ref 5.15). Note that this function is assumed to be available in the UFSAR Chapter 15 Safety Analysis but no specific setpoint is assumed (Refs 5.1 & 5.2).
4.1.27 Permissive P-13, Turbine Impulse Pressure Allowable Value : < 11.0 % RTP (Refs. 5.1, 5.8 & 5.56)
This Allowable Value of < 11.0 % RTP is based on maintaining a Nominal Trip Setpoint value of 10.0
% RTP. In this case, the current Allowable Value of < 11.0 % RTP will be retained because it is conservative based on the methodologies described in Section 3.4.2. Note that this function is assumed to be available in the UFSAR Chapter 15 Safety Analysis but no specific setpoint is assumed (Refs 5.1
& 5.2).
4.1.28 Reactor Trip Breakers Allowable Value : N/A (Ref. 5.8 )
There is no specific RTS Trip Setpoint associated with this function.
4.1.29 Reactor Trip Breaker Undervoltage and Shunt Trip Mechanism Allowable Value : N/A (Ref. 5.8)
There is no specific RTS Trip Setpoint associated with this function.
4.1.30 Automatic Trip Logic Allowable Value : N/A (Ref. 5.8)
There is no specific RTS Trip Setpoint associated with this function.
EE-0116 Page 69 of 205 Revision 7 4.2 Allowable Values for North Anna ITS Table 3.3.2-1 (ESFAS Instrumentation)
Safety Injection 4.2.1 Safety Injection, Manual Initiation Allowable Value : N/A (Ref. 5.8)
There is no specific ESFAS Trip Setpoint associated with this function.
4.2.2 Safety Injection Automatic Actuation Logic and Actuation Relays Allowable Value : N/A (Ref. 5.8)
There is no specific ESFAS Trip Setpoint associated with this function.
4.2.3 Containment Pressure - High Allowable Value : < 17.7 PSIA (Refs. 5.1, 5.8, 5.25 & 5.55)
Subtracting the Total Loop Uncertainty (TLU) from the Analytical Limit (AL) yields a Maximum Trip Setpoint (MTS) of 18.52 PSIA. Subtracting the NON COT error components from the Analytical Limit yields a Maximum Allowable Value (MAV) of 18.74 PSIA. The Actual Nominal Trip Setpoint of 17.0 PSIA is conservative with respect to the Maximum Trip Setpoint and the Actual Allowable Value of <
17.7 PSIA is conservative with respect to the Maximum Allowable Value. This Allowable Value of <
17.7 PSIA is based on maintaining a Nominal Trip Setpoint value of 17.0 PSIA. The current ITS Allowable Value of < 17.7 PSIA is approximately equal to the calculated COTerror shown below.
The statistical combination of the COT and NON COT error components from CSA Calculation EE-0052 (Ref. 5.25) are given below. The COT and NON COT error components are used in Figure 4.2.3 to determine the Maximum Trip Setpoint (MTS) and the Maximum Allowable Value (MAV).
NON COTerror = [PMA2 + PEA2 + (SCA+SMTE)2 + SD2 + SPE2 + STE2 + SPSE2 + M1MTE2 +
M3MTE2 + RTE2] 1/2 NON COTerror = [0.02 + 0.02 + (0.5+0.18)2 + 0.3082 + 0.02 + 1.1582 + 0.02 + 0.1532 + 0.032 + 0.52] 1/2 NON COTerror = + 1.474 % of span = + 0.958 PSIA COTerror = + (M12 + M32 + RD2) 1/2 COTerror = + (0.12 + 0.252 + 1.02) 1/2 COTerror = + 1.036 % of span = + 0.673 PSIA See Figure 4.2.3 for specific details.
EE-0116 Page 70 of 205 Revision 7 NORTH ANNA'S CONTAINMENT PRESSURE HI-1 ESFAS INITIATION Analytical Limit (AL) 19.7 PSIA NON-COT ERRORS 0.958 PSIA TOTAL LOOP 1.18 PSIA Maximum Allowable Value (MAV)
UNCERTAINTY (TLU) 18.74 PSIA COT ERRORS 0.222 PSIA Maximum Trip Setpoint (MTS) 18.52 PSIA Actual Allowable Value (AV) 17.7 PSIA COT ERRORS SAFETY MARGIN 0.70 PSIA 1.52 PSIA Actual Trip Setpoint (ATS) 17.0 PSIA OPERATING MARGIN 5.0 PSIA High Operating Limit 12.0 PSIA Nominal Operating Limit 10.5 PSIA Figure 4.2.3
EE-0116 Page 71 of 205 Revision 7 4.2.4 Pressurizer Pressure Low-Low Allowable Value : > 1770 PSIG (Refs. 5.1, 5.8, 5.19 & 5.44)
Adding the Total Loop Uncertainty (TLU) to the Analytical Limit (AL) yields a Minimum Trip Setpoint (MTS) of 1768.22 PSIG. Adding the NON COT error components to the Analytical Limit yields a Minimum Allowable Value (MAV) of 1766.45 PSIG. The Actual Nominal Trip Setpoint of 1780 PSIG is conservative with respect to the Minimum Trip Setpoint and the Actual Allowable Value of 1770 PSIG is conservative with respect to the Minimum Allowable Value. This Allowable Value of > 1770 PSIG is based on maintaining a Nominal Trip Setpoint value of 1780 PSIG.
In this case, the current Allowable Value of > 1770 PSIG will be retained because it is sufficiently close enough to the calculated value using the CSA rack error terms from Calculation EE-0069 (Ref 5.19).
The calculated Allowable Value for this function is > 1771.71 PSIG. The 1.71 PSIG offset is accommodated in the 11.78 PSIG Safety Margin for this trip as illustrated in Figure 4.2.4.
The statistical combination of the COT and NON COT error components from CSA Calculation EE-0069 (Ref. 5.19) are given below. The COT and NON COT error components are used in Figure 4.2.4 to determine the Minimum Trip Setpoint (MTS) and the Minimum Allowable Value (MAV).
NON COTerror = SE + EA + [(SCA+SMTE)2 + SD2 + SPE2 + STE2 + M1MTE2 + RCSAMTE2 +
RTE2] 1/2 NON COTerror = 1.88 + 4.00 + [0.9042 + 0.752 + 0.02 + 2.0132 + 0.1532 + 0.032 + 0.52] 1/2 NON COTerror = + 8.269 % of span = + 66.152 PSIG (worst case)
COTerror = + (M12 + RCSA2 + RD2) 1/2 COTerror = + (0.12 + 0.252 + 1.02) 1/2 COTerror = + 1.036 % of span = + 8.29 PSIG See Figure 4.2.4 for specific details.
EE-0116 Page 72 of 205 Revision 7 NORTH ANNA'S PRESSURIZER LO-2 PRESSURE ESFAS INITIATION Nominal Operating Limit 2235 PSIG Low Operating Limit 2210 PSIG OPERATING MARGIN 430 PSIG Actual Trip Setpoint (ATS) 1780 PSIG COT ERRORS 10.0 PSIG SAFETY MARGIN 11.78 PSIG Actual Allowable Value (AV) 1770 PSIG Minimum Trip Setpoint (MTS) 1768.22 PSIG COT ERRORS 1.768 PSIG TOTAL LOOP 67.92 PSIG Minimum Allowable Value (MAV) 1766.45 UNCERTAINTY (TLU)
NON-COT ERRORS 66.152 PSIG Analytical Limit (AL) 1700.3 PSIG Figure 4.2.4
EE-0116 Page 73 of 205 Revision 7 4.2.5 High Differential Pressure Between Steam Lines Allowable Value : < 112.0 PSID (Refs. 5.1, 5.8, 5.26 & 5.50)
Subtracting the Total Loop Uncertainty (TLU) from the Analytical Limit (AL) yields a Maximum Trip Setpoint (MTS) of 111.9 PSID. Subtracting the NON COT error components from the Analytical Limit yields a Maximum Allowable Value (MAV) of 115.66 PSID. The Actual Nominal Trip Setpoint of 100.0 PSIA is conservative with respect to the Maximum Trip Setpoint and the Actual Allowable Value of < 112.0 PSID is conservative with respect to the Maximum Allowable Value. This Allowable Value of < 112.0 PSID is based on maintaining a Nominal Trip Setpoint value of 100.0 PSID. The current ITS Allowable Value of < 112.0 PSID is conservative with respect to the calculated COTerror shown below.
The statistical combination of the COT and NON COT error components from CSA Calculation EE-0121 (Ref. 5.26) are given below. The COT and NON COT error components are used in Figure 4.2.5 to determine the Maximum Trip Setpoint (MTS) and the Maximum Allowable Value (MAV).
NON COTerror = SE + [EA2 + PMA2 + PEA2 + (SCA+SMTE)2 + SD2 + SPE2 + STE2 + SPSE2 +
M1MTE2 + M6MTE2 + RTE2] 1/2 NON COTerror = 0.0 + [0.02 + 0.02 + 0.02 + (1.0+0.0)2 + 0.6072 + 0.02 + 2.0862 + 0.2162 + 0.0422 +
0.52] 1/2 NON COTerror = + 2.453 % of span = + 34.34 PSID COTerror = + (M12 + M62 + RD2) 1/2 COTerror = + (0.1412 + 0.52 + 1.02) 1/2 COTerror = + 1.127 % of span = + 15.78 PSID
EE-0116 Page 74 of 205 Revision 7 NORTH ANNA'S HI dP BETWEEN STEAM LINES ESFAS INITIATION Analytical Limit (AL) 150.0 PSID NON-COT ERRORS 34.34 PSID TOTAL LOOP 38.1 PSID UNCERTAINTY (TLU)
Maximum Allowable Value (MAV) 115.66 PSID COT ERRORS 3.76 PSIA Actual Allowable Value (AV) 112.0 PSID Maximum Trip Setpoint (MTS) 111.9 PSID COT ERRORS 12.0 PSID SAFETY MARGIN 11.9 PSIA Actual Trip Setpoint (ATS) 100.0 PSID OPERATING MARGIN 80.0 PSIA High Operating Limit 20.0 PSID Nominal Operating Limit 0.0 PSID Figure 4.2.5 4.2.6 High Steam Flow in Two Steam Lines Allowable Value : < 42.0 % of Flownom from 0 to 20 % Power, increasing linearly to
< 111.0 % of Flownom at 100 % Power. (Refs. 5.1, 5.8, 5.23 & 5.49)
Subtracting the Total Loop Uncertainty (TLU = 2.436 % of P span) from the Analytical Limit (AL =
20.715 % of P span from 0 % to 20 % power, the most limiting condition) yields a Maximum Trip Setpoint (MTS) of 18.279 % of P span. Subtracting the NON COT error components from the Analytical Limit yields a Maximum Allowable Value (MAV) of 18.414 % of P span. The Actual Nominal Trip Setpoint of 9.39 % of P span (from 0 % to 20 % power, the most limiting condition) is conservative with respect to the Maximum Trip Setpoint and the Actual Allowable Value of < 10.19 %
of P span is conservative with respect to the Maximum Allowable Value. This Allowable Value of <
10.19 % of P span is based on maintaining a Nominal Trip Setpoint value of 9.39 % of P span. See Figure 4.2.6 for specific details.
EE-0116 Page 75 of 205 Revision 7 The statistical combination of the COT and NON COT error components from CSA Calculation EE-0736 (Ref. 5.23) are given below. The COT and NON COT error components are modified below to reflect 20 % power conditions. These error components are used in Figure 4.2.6 to determine the Maximum Trip Setpoint (MTS) and the Maximum Allowable Value (MAV).
CSA6NON COTerror = [EA2 + PMA2 + PEA2 + (SCA+SMTE)2 + SD2 + SPSE2 + STE2 + SPE2 +
M1MTE2 + RTE2] 1/2 CSA6NON COTerror = [0.02 + 1.0372 + 0.02 + (0.5+0.189)2 + 0.3532 + 0.02 + 1.2772 + 0.4092 + 0.1532 +
0.1732] 1/2 CSA6NON COTerror = + 1.878 % of P span (The PMA and RTE terms were converted from % Flow to
% P for 20 % power conditions. See Note 1)
CSA7NON COTerror = [EA2 + PMA2 + PEA2 + (SCA+SMTE)2 + SD2 + SPSE2 + STE2 + SPE2 +
M13MTE2 + M14MTE2 +M15MTE2] 1/2 CSA7NON COTerror = [0.02 + 0.02 + 0.02 + (0.5+0.205)2 + 0.2782 + 0.02 + 1.0792 + 0.02 + 0.1532 +
0.0422 + 0.0422] 1/2 CSA7NON COTerror = + 1.329 % of P span TOTAL NON COTerror = + (1.8782 + 1.3292)1/2 = + 2.301 % of P span CSA6 & 7COTerror P span = + (M12 + M132 + M142 + M152 + RD2)1/2 CSA6&7COTerror = + (0.12 + 0.12 + 0.52 + 0.52 + 0.3462) 1/2 CSA6&7COTerror = + 0.800 % of P span (The RD term was converted from % Flow to % P for 20 %
power conditions. See Note 1)
The Total Loop Uncertainty (TLU) for 20 % power used in Figure 4.2.6 is equal to :
TLU = (TOTAL NON COTerror2 + CSA6&7COTerror2) 1/2 = (2.3012 + 0.8002) 1/2 = 2.436 % P span Note 1: Calculation EE-0736 specifies a 3.0 % of flow span PMA value, a 0.5 % of flow span RTE value, and a 1.0 % of flow span RD value. Equation 03 from EE-0736 is used to convert from % of Flow span to % of P span. Equation 03 modified for a generic conversion from % of Flow span to % P of span is % P span = [%
Flow span / 0.5] / [Flowmax / Flow x]. Flowmax is the maximum indicated flowrate (i.e., 5
- 106 PPH) and Flow x is the flowrate of interest. At 20 % power, Flow x = 20 % Flow, noting that the nominal flowrate at 100 %
power is equal to 4.247
- 106 PPH. To bound this analysis for the MUR uprate on both units at North Anna, the nominal flow rate will be increased by 1.7 %, i.e., 4.247
- 106 PPH
- 1.017 = 4.319
- 106 PPH. Flow x = 0.2
- 4.319
- 106 PPH = 0.8638
- 106 PPH.
% P span(PMA) = [3.0 / 0.5] / [5.0 / 0.8638] = 1.037 % P span
% P span(RTE) = [0.5 / 0.5] / [5.0 / 0.8638] = 0.173 % P span
% P span(RD) = [1.0 / 0.5] / [5.0 / 0.8638] = 0.346 % P span
EE-0116 Page 76 of 205 Revision 7 NORTH ANNA'S HI STEAM FLOW IN TWO STEAM LINES ESFAS INITIATION Analytical Limit (AL) 20.715 % dP NON-COT ERRORS 2.301 % dP span span TOTAL LOOP 2.436 % dP span Maximum Allowable Value (MAV)
UNCERTAINTY (TLU) 0.135 % dP span 18.414 % dP span COT ERRORS Maximum Trip Setpoint (MTS) 18.279 % dP span Actual Allowable Value (AV) 10.19 % dP span COT ERRORS 0.80 % dP span SAFETY MARGIN 8.889 % dP span OPERATING MARGIN 6.41 % dP span Actual Trip Setpoint (ATS) 9.39 % dP span based on 20 % High Operating Limit of Fnom (4.319 MPPH) 9.39 % dP span Nominal Operating Limit 2.98 % dP span (20 % of Flow nom)
Figure 4.2.6 Notes:
- 1. Flowmax = 5.0 MPPH and Pre-MUR Flownom = 4.247 MPPH. Based on Technical Report EE-0085, Appendix 18-5 (Ref.
5.13), the equation used to convert from % Flownom to % P span is : % P span (Unit 1) = ((% Flownom / Flowmax)2 /
1.25060))
- 100. % P span (Unit 2) = ((% Flownom / Flowmax)2 / 1.25383))
- 100. See the example below for the conversion of the Analytical Limit of 60 % of Flownom to % P span:
Unit 1 = ((0.6
- 4.247) / 5.0)2 / 1.25060))
- 100 = 20.77 % P span Unit 2 = ((0.6
- 4.247) / 5.0)2 / 1.25383))
- 100 = 20.715 % P span (Bounding value used above)
- 2. Flowmax = 5.0 MPPH and Post-MUR Flownom = 4.247 MPPH
- 1.7 % = 4.319 MPPH. Based on Technical Report EE-0085, Appendix 18-5 (Ref. 5.13), the equation used to convert from % Flownom to % P span is : % P span (Unit 1) = ((%
Flownom / Flowmax)2 / 1.25528))
- 100. % P span (Unit 2) = ((% Flownom / Flowmax)2 / 1.25863))
- 100. See the example below for the conversion of the Analytical Limit of 60 % of Flownom to % P span:
Unit 1 (Post MUR Pref(est) = 814.2 psig) = ((0.6
- 4.319) / 5.0)2 / 1.25528))
- 100 = 21.399 % P span Unit 2 (Post MUR Pref(est) = 812.15 psig) = ((0.6
- 4.319) / 5.0)2 / 1.25863))
- 100 = 21.342 % P span
EE-0116 Page 77 of 205 Revision 7 4.2.7 TAVG Low-Low Allowable Value : > 542.0 oF (Refs. 5.1, 5.8, 5.18 & 5.47)
Adding the Total Loop Uncertainty (TLU) to the Analytical Limit (AL) yields a Minimum Trip Setpoint (MTS) of 541.474 oF. Adding the NON COT error components to the Analytical Limit yields a Minimum Allowable Value (MAV) of 540.45 oF. The Actual Nominal Trip Setpoint of 543.0 oF is conservative with respect to the Minimum Trip Setpoint and the Actual Allowable Value of > 542.0 oF is conservative with respect to the Minimum Allowable Value. This Allowable Value of > 542.0 oF is based on maintaining a Nominal Trip Setpoint value of 543.0 oF.
The statistical combination of the COT and NON COT error components from CSA Calculation EE-0434 (Ref. 5.18) are given below. The COT and NON COT error components are used in Figure 4.2.7 to determine the Minimum Trip Setpoint (MTS) and the Minimum Allowable Value (MAV).
CSA13NON COTerror = [EA2 + PEA2 + (SCARTD+SMTERTD)2 + (SCARTD+SMTERTD)2
+ (SCARTD+SMTERTD)2 + (SCARTD+SMTERTD)2 + (4
- SDRTD2)+ STERTD2 + M1MTE2 + M2MTE2
+ M3MTE2 + M4MTE2 + M5MTE2 + M7MTE2 + M20MTE2 + M26MTE2 + RTE2] 1/2 CSA13NON COTerror = [0.02 + 0.02 + (0.417+0.167)2 + (0.417+0.167)2 + (0.417+0.167)2 +
(0.417+0.167)2 + (4
- 0.252) + 0.02 + 0.232 + 0.232 + 0.232 + 0.232 + 0.122 + 0.092 + 0.062 + 0.032 +
0.52] 1/2 CSA13NON COTerror = + 1.450 % of span = + 1.450 oF CSA13COTerror = + (M12 + M22 + M32 + M42 + M52 + M72 + M202 + M262 + RD2) 1/2 CSA13COTerror = + (0.52 + 0.52 + 0.52 + 0.52 + 0.52 + 0.52 + 0.52 + 0.252 + 1.02) 1/2 CSA13COTerror = + 1.677 % of span = + 1.677 oF See Figure 4.2.7 for specific details.
EE-0116 Page 78 of 205 Revision 7 NORTH ANNA'S TAVG LOW LOW ESFAS INITIATION Nominal Operating Limit 547 °F Low Operating Limit 544°F OPERATING MARGIN 1.0 °F Actual Trip Setpoint (ATS) 543 °F COT ERRORS SAFETY MARGIN 1.0 °F 1.0 °F Actual Allowable Value (AV) 542 °F Minimum Trip Setpoint (MTS) 541.474 °F COT ERRORS 1.024 °F TOTAL LOOP 2.474 °F Minimum Allowable Value (MAV) 540.45°F NON-COT ERRORS UNCERTAINTY (TLU) 1.450 °F Analytical Limit (AL) 539.0 °F Figure 4.2.7 4.2.8 Steam Line Pressure - Low Allowable Value : > 585.0 PSIG (Refs. 5.1, 5.8, 5.26 & 5.50)
Adding the Total Loop Uncertainty (TLU) to the Analytical Limit (AL) yields a Minimum Trip Setpoint (MTS) of 474.1 PSIG. Adding the NON COT error components to the Analytical Limit yields a Minimum Allowable Value (MAV) of 469.09 PSIG. The Actual Nominal Trip Setpoint of 600 PSIG is conservative with respect to the Minimum Trip Setpoint and the Actual Allowable Value of > 585 PSIG is conservative with respect to the Minimum Allowable Value. This Allowable Value of > 585 PSIG is based on maintaining a Nominal Trip Setpoint value of 600 PSIG. Also note that this function is dynamically compensated.
The statistical combination of the COT and NON COT error components from CSA Calculation EE-0121 (Ref. 5.26) are given below. The COT and NON COT error components are used in Figure 4.2.8 to determine the Minimum Trip Setpoint (MTS) and the Minimum Allowable Value (MAV).
EE-0116 Page 79 of 205 Revision 7 NON COTerror = SE + [EA2 + PMA2 + PEA2 + (SCA+SMTE)2 + SD2 + SPE2 + STE2 + M1MTE2 +
M4MTE2 + M5MTE2 + RTE2] 1/2 NON COTerror = 0.0 + [0.02 + 0.02 + 0.02 + (0.5+0.207)2 + 0.4292 + 0.02 + 1.4752 + 0.1532 + 0.0422 +
0.032 + 0.52] 1/2 NON COTerror = + 1.771 % of span = + 24.79 PSIG COTerror = + (M12 +M42 + +M52 + RD2) 1/2 COTerror = + (0.12 + 0.52 + 0.252 + 1.02) 1/2 COTerror = + 1.15 % of span = + 16.1 PSIG See Figure 4.2.8 for specific details.
NORTH ANNA'S STEAM LINE PRESSURE LOW ESFAS INITIATION Nominal Operating Limit 825 PSIG Low Operating Limit 635 PSIG OPERATING MARGIN 35 PSIG (Static)
Actual Trip Setpoint (ATS) 600 PSIG COT ERRORS 15.0 PSIG SAFETY MARGIN 125.9 PSIG (Static)
Actual Allowable Value (AV) 585 PSIG Minimum Trip Setpoint (MTS) 474.1 PSIG COT ERRORS 5.01 PSIG TOTAL LOOP 29.8 PSIG Minimum Allowable Value (MAV) 469.09 PSIG UNCERTAINTY (TLU)
NON-COT ERRORS 24.79 PSIG Analytical Limit (AL) 444.3 PSIG Figure 4.2.8
EE-0116 Page 80 of 205 Revision 7 Containment Spray 4.2.9 Containment Spray, Manual Initiation Allowable Value : N/A (Refs. 5.1 & 5.8)
There is no specific ESFAS Trip Setpoint associated with this function.
4.2.10 Containment Spray Automatic Actuation Logic and Actuation Relays Allowable Value : N/A (Refs. 5.1 & 5.8)
There is no specific ESFAS Trip Setpoint associated with this function.
4.2.11 Containment Pressure High - High Allowable Value : < 28.45 PSIA (Refs. 5.1, 5.8, 5.25 & 5.55)
Subtracting the Total Loop Uncertainty (TLU) from the Analytical Limit (AL) yields a Maximum Trip Setpoint (MTS) of 28.82 PSIA. Subtracting the NON COT error components from the Analytical Limit yields a Maximum Allowable Value (MAV) of 29.04 PSIA. The Actual Nominal Trip Setpoint of 27.75 PSIA is conservative with respect to the Maximum Trip Setpoint and the Actual Allowable Value of <
28.45 PSIA is conservative with respect to the Maximum Allowable Value. This Allowable Value of <
28.45 PSIA is based on maintaining a Nominal Trip Setpoint value of 27.75 PSIA. The current ITS Allowable Value of < 28.45 PSIA is slightly greater than the calculated COTerror shown below but the offset is accommodated in the Safety Margin illustrated in Figure 4.2.11.
The statistical combination of the COT and NON COT error components from CSA Calculation EE-0052 (Ref. 5.25) are given below. The COT and NON COT error components are used in Figure 4.2.11 to determine the Maximum Trip Setpoint (MTS) and the Maximum Allowable Value (MAV).
NON COTerror = [PMA2 + PEA2 + (SCA+SMTE)2 + SD2 + SPE2 + STE2 + SPSE2 + M1MTE2 +
M3MTE2 + RTE2] 1/2 NON COTerror = [0.02 + 0.02 + (0.5+0.18)2 + 0.3082 + 0.02 + 1.1582 + 0.02 + 0.1532 + 0.032 + 0.52] 1/2 NON COTerror = + 1.474 % of span = + 0.958 PSIA COTerror = + (M12 + M32 + RD2) 1/2 COTerror = + (0.12 + 0.252 + 1.02) 1/2 COTerror = + 1.036 % of span = + 0.673 PSIA See Figure 4.2.11 for specific details.
EE-0116 Page 81 of 205 Revision 7 NORTH ANNA'S CONTAINMENT PRESSURE HI-3 ESFAS INITIATION Analytical Limit (AL) 30.0 PSIA NON-COT ERRORS 0.958 PSIA TOTAL LOOP 1.18 PSIA Maximum Allowable Value (MAV)
UNCERTAINTY (TLU) 29.04 PSIA COT ERRORS 0.222 PSIA Maximum Trip Setpoint (MTS) 28.82 PSIA Actual Allowable Value (AV) 28.45 PSIA COT ERRORS SAFETY MARGIN 0.70 PSIA 1.07 PSIA Actual Trip Setpoint (ATS) 27.75 PSIA OPERATING MARGIN 15.75 PSIA High Operating Limit 12.0 PSIA Nominal Operating Limit 10.5 PSIA Figure 4.2.11
EE-0116 Page 82 of 205 Revision 7 Containment Isolation - Phase A 4.2.12 Containment Isolation - Phase A, Manual Initiation Allowable Value : N/A (Ref. 5.8)
There is no specific ESFAS Trip Setpoint associated with this function.
4.2.13 Containment Isolation - Phase A, Automatic Actuation Logic and Actuation Relays Allowable Value : N/A (Ref. 5.8)
There is no specific ESFAS Trip Setpoint associated with this function.
4.2.14 Safety Injection Allowable Value : N/A (Ref. 5.8)
See Items 4.2.1 through 4.2.8.
Containment Isolation - Phase B 4.2.15 Containment Isolation - Phase B, Manual Initiation Allowable Value : N/A (Ref. 5.8)
There is no specific ESFAS Trip Setpoint associated with this function.
4.2.16 Containment Isolation - Phase B, Automatic Actuation Logic and Actuation Relays Allowable Value : N/A (Ref. 5.8)
There is no specific ESFAS Trip Setpoint associated with this function.
4.2.17 Containment Pressure High - High Allowable Value : See Item 4.2.11
EE-0116 Page 83 of 205 Revision 7 Steam Line Isolation 4.2.18 Steam Line Isolation, Manual Initiation Allowable Value : N/A (Ref. 5.8)
There is no specific ESFAS Trip Setpoint associated with this function.
4.2.19 Steam Line Isolation, Automatic Actuation Logic and Actuation Relays Allowable Value : N/A (Ref. 5.8)
There is no specific ESFAS Trip Setpoint associated with this function.
4.2.20 Containment Pressure Intermediate High - High Allowable Value : < 18.5 PSIA (Refs. 5.1, 5.8, 5.25 & 5.55)
Subtracting the Total Loop Uncertainty (TLU) from the Analytical Limit (AL) yields a Maximum Trip Setpoint (MTS) of 18.82 PSIA. Subtracting the NON COT error components from the Analytical Limit yields a Maximum Allowable Value (MAV) of 19.04 PSIA. The Actual Nominal Trip Setpoint of 17.8 PSIA is conservative with respect to the Maximum Trip Setpoint and the Actual Allowable Value of <
18.5 PSIA is conservative with respect to the Maximum Allowable Value. This Allowable Value of <
18.5 PSIA is based on maintaining a Nominal Trip Setpoint value of 17.8 PSIA. The current ITS Allowable Value of < 18.5 PSIA is slightly greater than the calculated COTerror shown below but the offset is accommodated in the Safety Margin illustrated in Figure 4.2.20.
The statistical combination of the COT and NON COT error components from CSA Calculation EE-0052 (Ref. 5.25) are given below. The COT and NON COT error components are used in Figure 4.2.20 to determine the Maximum Trip Setpoint (MTS) and the Maximum Allowable Value (MAV).
NON COTerror = [PMA2 + PEA2 + (SCA+SMTE)2 + SD2 + SPE2 + STE2 + SPSE2 + M1MTE2 +
M3MTE2 + RTE2] 1/2 NON COTerror = [0.02 + 0.02 + (0.5+0.18)2 + 0.3082 + 0.02 + 1.1582 + 0.02 + 0.1532 + 0.032 + 0.52] 1/2 NON COTerror = + 1.474 % of span = + 0.958 PSIA COTerror = + (M12 + M32 + RD2) 1/2 COTerror = + (0.12 + 0.252 + 1.02) 1/2 COTerror = + 1.036 % of span = + 0.673 PSIA See Figure 4.2.20 for specific details.
EE-0116 Page 84 of 205 Revision 7 NORTH ANNA'S CONTAINMENT PRESSURE HI-2 ESFAS INITIATION Analytical Limit (AL) 20.0 PSIA NON-COT ERRORS 0.958 PSIA TOTAL LOOP 1.18 PSIA Maximum Allowable Value (MAV)
UNCERTAINTY (TLU) 19.04 PSIA COT ERRORS 0.222 PSIA Maximum Trip Setpoint (MTS) 18.82 PSIA Actual Allowable Value (AV) 18.5 PSIA COT ERRORS SAFETY MARGIN 0.70 PSIA 1.02 PSIA Actual Trip Setpoint (ATS) 17.8 PSIA OPERATING MARGIN 5.8 PSIA High Operating Limit 12.0 PSIA Nominal Operating Limit 10.5 PSIA Figure 4.2.20 4.2.21 High Steam Flow in Two Steam Lines Allowable Value : See Item 4.2.6 4.2.22 TAVG Low-Low Allowable Value : See Item 4.2.7.
4.2.23 Steam Line Pressure - Low Allowable Value : See Item 4.2.8
EE-0116 Page 85 of 205 Revision 7 Turbine Trip and Feedwater Isolation 4.2.24 Turbine Trip and Feedwater Isolation, Automatic Actuation Logic and Actuation Relays Allowable Value : N/A (Ref. 5.8)
There is no specific ESFAS Trip Set point associated with this function.
4.2.25 SG Water Level - High High (P-14)
Allowable Value : < 76.0 % Narrow Range (NR) Level (Refs. 5.1, 5.8, 5.22 & 5.48)
Subtracting the Total Loop Uncertainty (TLU) from the Analytical Limit (AL) yields a Maximum Trip Setpoint (MTS) of 98.024 % NR Level. Subtracting the NON COT error components from the Analytical Limit yields a Maximum Allowable Value (MAV) of 98.334 % NR Level. The Actual Nominal Trip Setpoint of 75.0 % NR Level is conservative with respect to the Maximum Trip Setpoint and the Actual Allowable Value of < 76.0 % NR Level is conservative with respect to the Maximum Allowable Value. This Allowable Value of < 76.0 NR Level is based on maintaining a Nominal Trip Setpoint value of 75.0 % NR Level.
The statistical combination of the COT and NON COT error components from CSA Calculation EE-0492 (Ref. 5.22) are given below. The COT and NON COT error components are used in Figure 4.2.25 to determine the Maximum Trip Setpoint (MTS) and the Maximum Allowable Value (MAV).
NON COTerror = SE + PMA2 + [PEA2 + (SCA+SMTE)2 + SD2 + SPE2 + STE2 + M1MTE2 + M2MTE2 +
RTE2] 1/2 NON COTerror = 0.0 + 0.0 + [0.02 + (0.5+0.383)2 + 0.2892 + 0.6352 + 1.1102 + 0.1582 + 0.052 + 0.52] 1/2 NON COTerror = + 1.666 % of span = + 1.666 % NR Level COTerror = + (M12 + M22 + RD2) 1/2 COTerror = + (0.12 + 0.252 + 1.02) 1/2 COTerror = + 1.036 % of span = + 1.036 % NR Level See Figure 4.2.25 for specific details.
EE-0116 Page 86 of 205 Revision 7 NORTH ANNA'S STEAM GENERATOR LEVEL HI-2 ESFAS INITIATION Analytical Limit (AL) 100.0 % NR Level TOTAL LOOP NON-COT ERRORS 1.666 % NR Level 1.976 % NR Level UNCERTAINTY (TLU)
Maximum Allowable Value (MAV) 98.334 % NR Level COT ERRORS 0.31% NR Level Maximum Trip Setpoint (MTS) 98.024 % NR Level Actual Allowable Value (AV)
SAFETY MARGIN 76.0 % NR Level COT ERRORS 1.0 % NR Level 23.024 % NR Level Actual Trip Setpoint (ATS) 75.0 % NR Level OPERATING MARGIN 26.0 % NR Level High Operating Limit 49.0 % NR Level Nominal Operating Limit 44.0 % NR Level Figure 4.2.25 4.2.26 Safety Injection Allowable Value : N/A See Items 4.2.1 through 4.2.8.
EE-0116 Page 87 of 205 Revision 7 Auxiliary Feedwater 4.2.27 Auxiliary Feedwater, Automatic Actuation Logic and Actuation Relays Allowable Value : N/A (Ref. 5.8)
There is no specific ESFAS Trip Setpoint associated with this function.
4.2.28 SG Water Level - Low Low Allowable Value : See item 4.1.17.
4.2.29 Safety Injection Allowable Value : N/A See items 4.2.1 through 4.2.8.
4.2.30 Loss of Offsite Power Allowable Value : This Allowable Value will be provided by Corporate Electrical EE Power.
4.2.31 Trip of all Main Feedwater Pumps Allowable Value : N/A (Ref. 5.8)
There is no specific ESFAS Trip Setpoint associated with this function.
Automatic Switch Over to Containment Sump 4.2.32 Containment Sump Auto Switch Over, Automatic Actuation Logic and Actuation Relays Allowable Value : N/A (Ref. 5.8)
There is no specific ESFAS Trip Setpoint associated with this function.
EE-0116 Page 88 of 205 Revision 7 4.2.33 Refueling Water Storage Tank Level - Low Low (Auto-Switchover to Containment Sump)
Allowable Values : > 15.0 % Wide Range (WR) Level and < 17.0 % Wide Range (WR) Level (Refs. 5.1, 5.8, 5.27, 5.52 & 5.86)
There are two Analytical Limits and thus two Allowable Values associated with this function. The Analytical Limits are > 13.5 % WR Level and < 18.5 % WR Level. The corresponding Allowable Values are > 15.0 % WR Level and < 17.0 WR Level. Both Allowable Values will be analyzed below.
Analysis for > 15.0 % Wide Range (WR) Level Adding the Total Loop Uncertainty (TLU) to the Analytical Limit (AL = 13.5 % WR Level) yields a Minimum Trip Setpoint (MTS) of 15.243 % WR Level. Adding the NON COT error components to the Analytical Limit yields a Minimum Allowable Value (MAV) of 14.868 % WR Level. The Actual Nominal Trip Setpoint of 16.0 % WR Level is conservative with respect to the Minimum Trip Setpoint.
The Actual Allowable Value of > 15.0 % WR Level is conservative with respect to the Minimum Allowable Value. The statistical combination of the COT and NON COT error components from CSA Calculation EE-0092 (Ref. 5.27) are given below. The COT and NON COT error components are used in Figure 4.2.33 to determine the Minimum Trip Setpoint (MTS) and the Minimum Allowable Value (MAV).
NON COTerror = SE + [EA2 + PMA2 + PEA2 + (SCA+SMTE)2 + SD2 + SPE2 + STE2 + SPSE2 +
M1MTE2 + M2MTE2 + RTE2] 1/2 NON COTerror = 0.064 + [0.02 + 0.0222 + 0.02 + (0.5+0.211)2 + 0.2222 + 0.02 + 0.9332 + 0.02 + 0.1532 +
0.032 + 0.52] 1/2 NON COTerror = + 1.368 % of span and - 1.24 % of span COTerror = + (M12 +M22 + RD2) 1/2 COTerror = + (0.12 +0.252 + 1.02) 1/2 COTerror = + 1.036 % of span Analysis for < 17.0 % Wide Range (WR) Level Subtracting the Total Loop Uncertainty (TLU) from the Analytical Limit (AL = 18.5 % WR Level) yields a Maximum Trip Setpoint (MTS) of 16.885 % WR Level. Subtracting the NON COT error components from the Analytical Limit yields a Maximum Allowable Value (MAV) of 17.26 % WR Level. The Actual Nominal Trip Setpoint of 16.0 % WR Level is conservative with respect to the Maximum Trip Setpoint. The Actual Allowable Value of < 17.0 % WR Level is slightly conservative with respect to the Maximum Allowable Value. The statistical combination of the COT and NON COT error components from CSA Calculation EE-0092 (Ref. 5.27) are given below. The COT and NON
EE-0116 Page 89 of 205 Revision 7 COT error components are used in Figure 4.2.33 to determine the Maximum Trip Setpoint (MTS) and the Maximum Allowable Value (MAV).
NON COTerror = SE + [EA2 + PMA2 + PEA2 + (SCA+SMTE)2 + SD2 + SPE2 + STE2 + SPSE2 +
M1MTE2 + M2MTE2 + RTE2] 1/2 NON COTerror = 0.064 + [0.02 + 0.0222 + 0.02 + (0.5+0.211)2 + 0.2222 + 0.02 + 0.9332 + 0.02 + 0.1532 +
0.032 + 0.52] 1/2 NON COTerror = + 1.368 % of span and - 1.24 % of span COTerror = + (M12 +M22 + RD2) 1/2 COTerror = + (0.12 +0.252 + 1.02) 1/2 COTerror = + 1.036 % of span See Figures 4.2.33 for specific details.
EE-0116 Page 90 of 205 Revision 7 NORTH ANNA'S RWST LEVEL LO-2 ESFAS INITIATION Nominal Operating Limit 97.6 % WR Level Low Operating Limit 96.7 % WR Level High Analytical Limit (AL) 18.50 % WR Level TOTAL LOOP NON-COT 1.615 % WR Level ERRORS 1.24 %
UNCERTAINTY (TLU)
OPERATING MARGIN Maximum Allowable Value (MAV) 80.7 % WR Level 17.26 % WR Level Actual Allowable Value (AV)
COT 17.0 % WR Level ERRORS 0.375 %
Maximum Trip Setpoint (MTS) 16.885 % WR Level COT SAFETY MARGIN 0.89% WR Level ERRORS 1.0 % WR Level Actual Trip Setpoint (ATS) 16.0 % WR Level SAFETY MARGIN 1.0 % WR Level 0.76 % WR Level COT ERRORS Minimum Trip Setpoint (MTS) 15.243 % WR Level COT ERRORS 0.375 % Actual Allowable Value (AV)
TOTAL LOOP 1.743 % WR Level 15.0 % WR Level Minimum Allowable Value (MAV) 14.868 % WR Level UNCERTAINTY (TLU)
NON-COT ERRORS 1.368 %
Low Analytical Limit (AL) 13.50 % WR Level Figure 4.2.33
EE-0116 Page 91 of 205 Revision 7 4.2.34 Refueling Water Storage Tank Low Level - RS Pump Start Allowable Values : > 59.0 % Wide Range (WR) Level and < 61.0 % Wide Range (WR) Level (Refs. 5.1, 5.8, 5.27, 5.52 & 5.86)
There are two Analytical Limits and thus two Allowable Values associated with this new function. The Analytical Limits are based on Technical Report NE-0994 (Ref. 5.1). The Analytical Limits are > 57.50
% WR Level and < 62.50 % WR Level. The corresponding Allowable Values to be used in Technical Specifications are > 59.00 % WR Level and < 61.00 % WR Level. Both Allowable Values will be analyzed below.
Analysis for > 59.00 % Wide Range (WR) Level Adding the Total Loop Uncertainty (TLU) to the Analytical Limit (AL) yields a Minimum Trip Setpoint (MTS) of 59.24 % WR Level. Adding the NON COT error components to the Analytical Limit yields a Minimum Allowable Value (MAV) of 58.868 % WR Level. The Actual Nominal Trip Setpoint of 60.00
% WR Level is conservative with respect to the Minimum Trip Setpoint. The Actual Allowable Value of > 59.00 % WR Level is conservative with respect to the Minimum Allowable Value. This Allowable Value of > 59.00 % WR Level is based on maintaining a Nominal Trip Setpoint value of 60.00 % WR Level. The proposed Allowable Value of > 59.00 % WR Level is conservative with respect to the calculated value using rack error terms (i.e., COT error terms) from Dominion Channel Statistical Allowance (CSA) Calculation EE-0092 (Reference 5.27).
Analysis for < 61.00 % Wide Range (WR) Level Subtracting the Total Loop Uncertainty (TLU) from the Analytical Limit (AL) yields a Maximum Trip Setpoint (MTS) of 60.885 % WR Level. Subtracting the NON COT error components from the Analytical Limit yields a Maximum Allowable Value (MAV) of 61.26 % WR Level. The Actual Nominal Trip Setpoint of 60.00 % WR Level is conservative with respect to the Maximum Trip Setpoint. The Actual Allowable Value of < 61.00 % WR Level is conservative with respect to the Maximum Allowable Value. This Allowable Value of < 61.00 % WR Level is based on maintaining a Nominal Trip Setpoint value of 60.00 % WR Level. The proposed Allowable Value of < 61.00 % WR Level is conservative with respect to the calculated value using rack error terms (i.e., COT error terms) from Dominion Channel Statistical Allowance (CSA) Calculation EE-0092 (Ref. 5.27).
The statistical combination of the COT and NON COT error components from CSA Calculation EE-0092 (Ref. 5.27) are given below. The COT and NON COT error components are used in Figure 4.2.34 to determine the Minimum/Maximum Trip Setpoints (MTS) and the Minimum/Maximum Allowable Values (MAV).
NON COTerror = SE + [EA2 + PMA2 + PEA2 + (SCA+SMTE)2 + SD2 + SPE2 + STE2 + SPSE2 +
M1MTE2 + M3MTE2 + RTE2]1/2 NON COTerror = 0.064 + [0.02 + 0.0222 + 0.02 + (0.5+0.211)2 + 0.2222 + 0.02 + 0.9332 + 0.02 + 0.1532 +
0.032 + 0.52]1/2
EE-0116 Page 92 of 205 Revision 7 NON COTerror = + 1.368 % of span and - 1.24 % of span COTerror = + (M12 +M22 + RD2) 1/2 COTerror = + (0.12 +0.252 + 1.02) 1/2 COTerror = + 1.036 % of span See Figure 4.2.34 for specific details.
NORTH ANNA'S RWST LEVEL LO ESFAS INITIATION Nominal Operating Limit 97.6 % WR Level Low Operating Limit 96.7 % WR Level High Analytical Limit (AL) 62.50 % WR Level TOTAL LOOP NON-COT 1.615 % WR Level ERRORS 1.24 %
Maximum Allowable Value (MAV)
UNCERTAINTY (TLU)
OPERATING 61.26% WR Level MARGIN COT Actual Allowable Value (AV) 0.375 %
36.7 % WR Level 61.0 % WR Level ERRORS Maximum Trip Setpoint (MTS) 60.89 % WR Level COT COT SAFETY MARGIN 0.89% WR Level ERRORS ERRORS Actual Trip Setpoint (ATS) 60.0 % WR Level SAFETY MARGIN 1.0 % WR Level 1.0 % WR Level 0.76 % WR Level Minimum Trip Setpoint (MTS) 59.24 % WR Level COT TOTAL LOOP ERRORS 1.743 % WR Level 0.375 % Actual Allowable Value 59.0 % WR Level Minimum Allowable Value UNCERTAINTY (TLU) 58.87 % WR Level NON-COT 1.368 %
ERRORS Low Analytical Limit (AL) 57.50 % WR Level Figure 4.2.34 Note: The COT errors are based on the Minimum Trip Setpoint value minus the Minimum Allowable value and the Actual Trip Setpoint value minus the Actual Allowable Value
EE-0116 Page 93 of 205 Revision 7 4.2.35 Safety Injection Allowable Value : N/A See Items 4.2.1 through 4.2.8.
ESFAS Permissives 4.2.36 Reactor Trip, P-4 Allowable Value : N/A (Ref. 5.8)
There is no specific ESFAS Trip Setpoint associated with this function.
4.2.37 Pressurizer Pressure, P-11 Allowable Value : < 2010 PSIG (Refs. 5.1, 5.8, 5.19, 5.44)
For North Annas ITS, only one Allowable Value will be provided for the P-11 function. The automatic disabling of the manual block of safety injection on increasing pressure is the portion of this function that is important to safety. The Allowable Value of < 2010 PSIG is based on maintaining a Nominal Trip Setpoint value of 2000 PSIG. In this case, the current value of < 2010 PSIG will be retained because it is sufficiently close enough to the calculated value using the methodologies described in Section 3.3 and the CSA rack error terms from Calculation EE-0069 (Ref 5.19). The calculated Allowable Value for this function is < 2008.3 PSIG. Note that this function is assumed to be available in the Safety Analysis but no specific setpoint is assumed and thus the margin of safety is not affected.
4.2.38 TAVG, P-12 Allowable Value : < 545.0 oF (Refs. 5.1, 5.8, 5.18, 5.47)
Subtracting the Total Loop Uncertainty (TLU) from the Analytical Limit (AL) yields a Maximum Trip Setpoint (MTS) of 544.526 oF. Subtracting the NON COT error components from the Analytical Limit yields a Maximum Allowable Value (MAV) of 545.55 oF. The Actual Nominal Trip Setpoint of 544.0 o
F is conservative with respect to the Maximum Trip Setpoint and the Actual Allowable Value of <
545.0 oF is conservative with respect to the Maximum Allowable Value.
The statistical combination of the COT and NON COT error components from CSA Calculation EE-0434 (Ref. 5.18) are given below. The COT and NON COT error components are used in Figure 4.2.38 to determine the Minimum Trip Setpoint (MTS) and the Minimum Allowable Value (MAV).
CSA13NON COTerror = [EA2 + PEA2 + (SCARTD+SMTERTD)2 + (SCARTD+SMTERTD)2 +
(SCARTD+SMTERTD)2 + (SCARTD+SMTERTD)2 + (4
- SDRTD2)+ STERTD2 + M1MTE2 + M2MTE2 +
M3MTE2 + M4MTE2 + M5MTE2 + M7MTE2 + M20MTE2 + M26MTE2 + RTE2] 1/2
EE-0116 Page 94 of 205 Revision 7 CSA13NON COTerror = [0.02 + 0.02 + (0.417+0.167)2 + (0.417+0.167)2 + (0.417+0.167)2 +
(0.417+0.167)2 + (4
- 0.252) + 0.02 + 0.232 + 0.232 + 0.232 + 0.232 + 0.122 + 0.092 + 0.062 + 0.032 +
0.52] 1/2 CSA13NON COTerror = + 1.450 % of span = + 1.450 oF CSA13COTerror = + (M12 + M22 + M32 + M42 + M52 + M72 + M202 + M262 + RD2) 1/2 CSA13COTerror = + (0.52 + 0.52 + 0.52 + 0.52 + 0.52 + 0.52 + 0.52 + 0.252 + 1.02) 1/2 CSA13COTerror = + 1.677 % of span = + 1.677 oF See Figure 4.2.38 for specific details.
NORTH ANNA'S ESFAS PERMISSIVE P-12 Analytical Limit (AL) 547.0 oF NON-COT ERRORS 1.450 oF TOTAL LOOP 2.474 oF Maximum Allowable Value (MAV) 545.55 oF UNCERTAINTY (TLU)
Actual Allowable Value 545.0 oF COT ERRORS COT ERRORS 1.024 oF 1.0 oF Maximum Trip Setpoint (MTS) 544.526 oF SAFETY MARGIN Actual Trip Setpoint
.53 oF 544.0 oF OPERATING MARGIN 1.0 oF High Operating Limit 543.0 oF Nominal Operating Limit 541.0 oF Figure 4.2.38
EE-0116 Page 95 of 205 Revision 7 4.3 Limiting Safety System Settings (LSSS) for Surry Power Station Custom Technical Specifications, Section 2.3, Limiting Safety System Settings, Protective Instrumentation and Protective Instrumentation Settings for Reactor Trip Interlocks.
Note: In the context of this document, the terms Allowable Value and Setting Limit and Limiting Safety System Setting (LSSS) have the same meaning and intent.
Reactor Trips 4.3.1 Power Range Neutron Flux High Setpoint Reactor Trip Allowable Value : < 109.0 % RTP (Refs. 5.1, 5.7, 5.28 & 5.81)
Subtracting the Total Loop Uncertainty (TLU) from the Analytical Limit (AL) yields a Maximum Trip Setpoint (MTS) of 110.48 % Rated Thermal Power (RTP). Subtracting the NON COT error components from the Analytical Limit yields a Maximum Allowable Value (MAV) of 111.08 % RTP.
The Actual Nominal Trip Setpoint of 107.0 % RTP is conservative with respect to the Maximum Trip Setpoint and the Actual Allowable Value of 109.0 % RTP is conservative with respect to the Maximum Allowable Value. This Allowable Value of < 109.0 % RTP is based on maintaining a Nominal Trip Setpoint value of 107.0 % RTP.
The calculated Allowable Value for this function is < 108.697 % RTP. The 0.303 % RTP offset is accommodated in the 3.48 % RTP Safety Margin for this trip as illustrated in Figure 4.3.1.
The statistical combination of the COT and NON COT error components from CSA Calculation EE-0198 (Ref. 5.28) are given below. The COT and NON COT error components are used in Figure 4.3.1 to determine the Maximum Trip Setpoint (MTS) and the Maximum Allowable Value (MAV).
NON COTerror = SE + (PMA12 + PMA22 + RMTE2 + RTE2) 1/2 NON COTerror = 0.0 + (2.0002 + 5.0002 + 2.0002 + 0.52) 1/2 NON COTerror = + 5.766 % of span = + 6.920 % RTP COTerror = + (RCA2 + RD2) 1/2 COTerror = + (1.02 + 1.02) 1/2 COTerror = + 1.414 % of span = + 1.697 % RTP See Figure 4.3.1 for specific details.
EE-0116 Page 96 of 205 Revision 7 SURRY'S POWER RANGE NEUTRON FLUX HIGH REACTOR TRIP Analytical Limit (AL) 118.00 % RTP COT ERRORS NON-COT ERRORS 6.92 % RTP TOTAL LOOP 7.52 % RTP Maximum Allowable Value (MAV)
UNCERTAINTY (TLU) 111.08 % RTP 0.60 % RTP Maximum Trip Setpoint (MTS) 110.48 % RTP Actual Allowable Value (AV) 109.00 % RTP COT ERRORS SAFETY MARGIN 2.00 % RTP 3.48 % RTP Actual Trip Setpoint (ATS) 107 % RTP OPERATING MARGIN 5.00 % RTP High Operating Limit 102.00 % RTP Nominal Operating Setpoint 100.00 % RTP Figure 4.3.1
EE-0116 Page 97 of 205 Revision 7 4.3.2 Power Range Neutron Flux Low Setpoint Reactor Trip Allowable Value : < 25.0 % RTP (Refs. 5.1, 5.7, 5.28 & 5.81)
Subtracting the Total Loop Uncertainty (TLU) from the Analytical Limit (AL) yields a Maximum Trip Setpoint (MTS) of 27.48 % Rated Thermal Power (RTP). Subtracting the NON COT error components from the Analytical Limit yields a Maximum Allowable Value (MAV) of 28.08 % RTP. The Actual Nominal Trip Setpoint of 23.0 % RTP is conservative with respect to the Maximum Trip Setpoint and the Actual Allowable Value of 25.0 % RTP is conservative with respect to the Maximum Allowable Value. This Allowable Value of < 25.0 % RTP is based on maintaining a Nominal Trip Setpoint value of 23.0 % RTP.
The calculated Allowable Value for this function is < 24.70 % RTP. The 0.30 % RTP offset is accommodated in the 4.48 % RTP Safety Margin for this trip as illustrated in Figure 4.3.2.
The statistical combination of the COT and NON COT error components from CSA Calculation EE-0198 (Ref. 5.28) are given below. The COT and NON COT error components are used in Figure 4.3.2 to determine the Maximum Trip Setpoint (MTS) and the Maximum Allowable Value (MAV).
NON COTerror = SE + (PMA12 + PMA22 + RMTE2 + RTE2) 1/2 NON COTerror = 0.0 + (2.0002 + 5.0002 + 2.0002 + 0.52) 1/2 NON COTerror = + 5.766 % of span = + 6.920 % RTP COTerror = + (M12 + RD2) 1/2 COTerror = + (1.02 + 1.02) 1/2 COTerror = + 1.414 % of span = + 1.697 % RTP See Figure 4.3.2 for specific details.
EE-0116 Page 98 of 205 Revision 7 SURRY'S POWER RANGE NEUTRON FLUX LOW SETPOINT REACTOR TRIP Analytical Limit (AL) 35.0 % RTP COT ERRORS NON-COT ERRORS 6.92 % RTP TOTAL LOOP 7.52 % RTP UNCERTAINTY (TLU)
Maximum Allowable Value (MAV) 28.08 % RTP 0.60 % RTP Maximum Trip Setpoint (MTS) 27.48 % RTP Actual Allowable Value (AV) 25.0 % RTP COT ERRORS SAFETY MARGIN 2.0 % Power 4.48 % RTP Actual Trip Setpoint (ATS) 23.0 % RTP OPERATING MARGIN 12.0 % RTP High Operating Limit 11.0 % RTP Nominal Operating Setpoint 10.0 % RTP Figure 4.3.2
EE-0116 Page 99 of 205 Revision 7 4.3.3 Intermediate Range Neutron Flux High Reactor Trip Allowable Value : < 40.0 % RTP (Refs. 5.1, 5.7, 5.29 & 5.82)
Subtracting the Total Loop Uncertainty (TLU) from the Analytical Limit (AL) yields a Maximum Trip Setpoint (MTS) of 88.18 % Rated Thermal Power (RTP). Subtracting the NON COT error components from the Analytical Limit yields a Maximum Allowable Value (MAV) of 89.627 % RTP. The Actual Nominal Trip Setpoint of 35.0 % RTP is conservative with respect to the Maximum Trip Setpoint and the Actual Allowable Value of 40.0 % RTP is conservative with respect to the Maximum Allowable Value. This Allowable Value of < 40.0 % RTP is based on maintaining a Nominal Trip Setpoint value of 35.0 % RTP.
The statistical combination of the COT and NON COT error components from CSA Calculation EE-0722 (Ref. 5.29) are given below. The COT and NON COT error components are used in Figure 4.3.3 to determine the Maximum Trip Setpoint (MTS) and the Maximum Allowable Value (MAV).
NON COTerror = SE + (EA2 + PMA2 + PEA2 + SCA2 + SD2 + SPE2 + RTE2 + RRA2) 1/2 NON COTerror = 0.0 + (0.02 + 8.4982 + 0.02 + 0.52 + 1.02 + 0.02 + 0.02 + 0.52 + 1.02)1/2 NON COTerror = + 8.644 % of span = + 10.373 % RTP COTerror = + [(M4 + M4MTE)2 + RD2) 1/2 COTerror = + [(1.003 + 3.622)2 + 1.002] 1/2 COTerror = + 4.732 % of span = + 5.678 % RTP Note: The M4MTE was included in the COTerror formula due to the meter being used for the adjustment of the bistable.
See Figure 4.3.3 for specific details.
EE-0116 Page 100 of 205 Revision 7 SURRY'S INTERMEDIATE RANGE HIGH FLUX REACTOR TRIP Analytical Limit (AL) 100.00 % RTP COT ERRORS NON-COT ERRORS 10.373 % RTP TOTAL LOOP 11.82 % Power UNCERTAINTY (TLU)
Maximum Allowable Value (MAV) 89.627 % RTP 1.447 % RTP Maximum Trip Setpoint (MTS) 88.18 % RTP Actual Allowable Value (AV) 40.0 % RTP COT ERRORS SAFETY MARGIN 5.00 % RTP 53.18 % RTP Actual Trip Setpoint (ATS) 35.00 % RTP OPERATING MARGIN 26.00 % RTP High Operating Limit 9.00 % RTP Nominal Operating Setpoint 8.00 % RTP Figure 4.3.3
EE-0116 Page 101 of 205 Revision 7 4.3.4 Source Range Neutron Flux High Reactor Trip Allowable Value : < 1.51
- 105 CPS (Refs. 5.1, 5.7, 5.30, 5.82)
Subtracting the Total Loop Uncertainty (TLU = + 0.93
- 105 and - 0.48
- 106 Counts Per Second (CPS). Subtracting the NON COT error components from the Analytical Limit yields a Maximum Allowable Value (MAV) of 1.27
- 106 CPS. The Actual Nominal Trip Setpoint of 1.0
- 105 CPS is conservative with respect to the Maximum Trip Setpoint. The current Allowable Value of < 1.00
- 106 CPS is conservative with respect to the Maximum Allowable Value. The current Allowable Value < 1.00
- 106 is not consistent with the calculated Allowable Values using the COT errors shown below. The Allowable Value will be changed from < 1.00
- 106 to < 1.51
- 105 CPS to conform to the methodology described in Sections 3.3.1 and 3.3.2.
The statistical combination of the COT and NON COT error components from CSA Calculation EE-0719 (Ref. 5.30) are given below. The COT and NON COT error components are used in Figure 4.3.4 to determine the Maximum Trip Setpoint (MTS) and the Maximum Allowable Value (MAV).
NON COTerror = SE + (PMA2 + PEA2 + (SCA+SMTE)2 + SD2 + SPE2 + SPSE2 + M1MTE2 + M2MTE2
+ RTE2 + RRA2)1/2 NON COTerror = 0.0 + (0.02 + 0.02 + (0.0+0.0)2 + 0.02 + 0.02 + 0.02 + 1.8172 + 1.02 + 0.52 + 0.02)1/2 NON COTerror = + 2.133 % of linear span
= + 0.34*105 CPS and - 0.25*105 CPS (Based on Trip Setpoint of 1.0*105 CPS)
= 0.34*105 CPS(1)
COTerror = + (M12 + M22 + RD2) 1/2 COTerror = + (1.6172 + 1.6172 + 1.92) 1/2 COTerror = + 2.973 % of linear span
= + 0.51*105 CPS and - 0.34*105 CPS (Based on the Nominal Trip Setpoint of 1.0*105 CPS)
= 0.51*105 CPS(2)
(1) Nominal Trip Setpoint = 1.0
- 105 CPS log 1.0
- 105 = 5.0 (on a 0 to 6 Decade scale)
Analytical Limit = 1.3
- 106 CPS log 1.3
- 106 = 6.11394 (on a 0 to 6 Decade scale)
Full CSA = + 4.744 % of linear span (4.744 %/100 %)
- 6 Decades = + 0.28464 Decade High Trip Setpoint = 5.0 + 0.28464 = 5.28464 antilog 5.28464 = 1.93
- 105 Low Trip Setpoint = 5.0 - 0.28464 = 4.71536 antilog 4.71536 = 0.52
- 105 CSA(+) = 1.93
- 105 - 1.0
- 105 = 0.93
- 105 and CSA(-) = 1.0
- 105 - 0.52
- 105 = 0.48
- 105 Full CSA = (+) 0.93
- 105 CPS and (-) 0.48
- 105 CPS (2) The most conservative value is used regardless of sign.
EE-0116 Page 102 of 205 Revision 7 SURRY'S SOURCE RANGE NEUTRON FLUX HIGH REACTOR TRIP Analytical Limit (AL) 1.3
- 106 CPS COT ERRORS NON-COT ERRORS 0.343
Maximum Allowable Value (MAV) 1.27
- 106 CPS 0.587
- 105 CPS COT ERRORS 0.51
- 105 CPS OPERATING MARGIN 2.00
- 104 CPS High Operating Limit 8.00
- 104 CPS Nominal Operating Limit 3.00
- 104 CPS Figure 4.3.4
EE-0116 Page 103 of 205 Revision 7 4.3.5 Overtemperature T Reactor Trip Allowable Value : See below (Refs. 5.1, 5.7, 5.31, 5.69, 5.71, 5.72, 5.73 & 5.74)
" The channel's maximum Trip Setpoint shall not exceed its computed Trip Setpoint by more than 2.0 % of the T span " (Note that 2.0 % of the T span is equal to 3.0 % T Power)
The Overtemperature T (OTT) Reactor Trip Setpoint equation in terms of process units is:
1 + 1 s OT T SP T o [ K 1 - K 2 * ( ) * (T - T ) + K 3 * (P - P ) - F( Q)]
1 + 2 s Where: (Equation 4.3.5)
T0 = Indicated T at rated thermal power, oF T = Average coolant temperature, oF T = 573.0 oF P = Pressurizer pressure, psig P = 2235 psig K1 = 1.135 K2 = 0.01072 K3 = 0.000566 I = qt - qb, where qt and qb are percent power in the top and bottom halves of the core respectively, and qt + qb is total core power in percent of rated power.
f(I) = function of I, percent of rated core power as shown in Surry TS Figure 2.3-1.
1 > 29.7 seconds 2 < 4.4 seconds The Overtemperature T (OTT) Reactor Trip Setpoint is variable and is constantly calculated based on actual plant conditions. For this reason, the Allowable Value cannot be expressed as a constant.
Further, the OTT Reactor Trip will be analyzed for the following three conditions:
- OTT Reactor Trip with no FI
- OTT Reactor Trip with (+) FI
- OTT Reactor Trip with (-) FI Note: FI is the Delta Flux Penalty generated from the Upper and Lower Power Range Neutron Flux Detectors (i.e., QU and QL).
Subtracting the Total Loop Uncertainty (TLU) from the Analytical Limit (AL) yields the following Maximum Trip Setpoints (MTS) for the three OTT Reactor Trip conditions described above:
- MTS for OTT Reactor Trip with no FI = 123.2 % - 7.956 % = 115.24 % T Power
- MTS for OTT Reactor Trip with (+) FI = 128.9 % - 9.788 % = 119.11 % T Power
- MTS for OTT Reactor Trip with (-) FI = 131.3 % - 11.355 % = 119.95 % T Power
EE-0116 Page 104 of 205 Revision 7 Subtracting the NON COT error components from the Analytical Limit yields the following Maximum Allowable Values (MAV) for the three OTT Reactor Trip conditions described above:
- MAV for OTT Reactor Trip with no FI = 123.2 % - 5.676 % = 117.52 % T Power
- MAV for OTT Reactor Trip with (+) FI = 128.9 % - 8.045 % = 120.855 % T Power
- MAV for OTT Reactor Trip with (-) FI = 131.3 % - 9.891 % = 121.409 % T Power For the most limiting condition (i.e., OTT Reactor Trip with no FI) the Actual Nominal Trip Setpoint of 111.5 % T Power (e.g., based on TAVG = 573.0 oF) is conservative with respect to the Maximum Trip Setpoint of 115.24 % T Power and the Actual Allowable Value of 114.5 % T Power is conservative with respect to the Maximum Allowable Value of 117.52 % T Power. This Allowable Value of < 114.5 % T Power is based on maintaining a Nominal Trip Setpoint value of 111.5 % T Power. Note that this analysis is based on static conditions such that dynamic components are not considered.
The statistical combination of the COT and NON COT error components from CSA Calculation EE-0415 (Ref. 5.31) with the appropriate modifications described in Section 3.2 for the OTT Reactor Trip are given below. The COT and NON COT error components are used in Figure 4.3.5b to determine the Maximum Trip Setpoint (MTS) and the Maximum Allowable Value (MAV) for the most limiting condition.
OTT Reactor Trip with no FI NON COTerror = [EAnon2 + PMATAVG2 + PMAT2 + PEA2 + (SCARTD +SMTERTD)2 + (SCARTD
+SMTERTD)2 + (SCARTD +SMTERTD)2 + (SCARTD +SMTERTD)2 + (4
- SDRTD2) + STERTD2 + PMAXMTR2
+ (SCAXMTR +SMTEXMTR)2 + SDXMTR2 + STEXMTR2 + FLUX12 + RMTE12 + RMTE22 + RMTE32 +
RMTE42 + RMTE52 + RMTE62 + RTE2]1/2 Where the following RMTE Terms are taken from Calculation EE-0415 (Ref. 5.31):
RMTE12 = T Channel Measuring and Test Equipment = (M1MTE2 + M2MTE2 + M3MTE2 +
M4MTE2 + M5MTE2 + M6MTE2) 1/2 RMTE12 = (0.2482 + 0.2482 + 0.2482 + 0.2442 + 0.302 + 0.262) 1/2 = 0.634 % of span RMTE22 = TAVG Channel Measuring and Test Equipment = (M1MTE2 + M2MTE2 + M3MTE2 +
M4MTE2 + M5MTE2 + M7MTE2 + M30MTE2 + M31MTE2) 1/2 RMTE22 = (0.2482 + 0.2482 + 0.2482 + 0.2442 + 0.302 + 0.262 + 0.2122 + 0.2122)1/2 = 0.701 % of span RMTE32 = Pressurizer Pressure Channel Measuring and Test Equipment = M45MTE2 RMTE32 = 0.212 % of span RMTE42 = FI Channel Measuring and Test Equipment = (M49MTE2 + M52MTE2) 1/2
EE-0116 Page 105 of 205 Revision 7 RMTE42 = (0.02 + 0.2122) 1/2 = 0.212 % of span RMTE52 = OTT Setpoint Summator Measuring and Test Equipment = M32MTE RMTE52 = 0.30 % of span RMTE62 = OTT Reactor Trip Bistable Measuring and Test Equipment = M33MTE RMTE62 = 0.212 % of span Thus, the NON COTerror is equal to:
NON COTerror = [0.002 + 1.702 + 1.302 + 0.002 + (0.417+0.167)2 + (0.417+0.167)2 + (0.417+0.167)2 +
(0.417+0.167)2 + (4
- 0.252) + 0.002 + 0.002 + (0.50+0.404)2 + 0.752 + 2.3192 + 0.002 + 0.6342 + 0.7012
+ 0.2122 + 0.2122 + 0.3002 + 0.2122 + 0.5002]1/2 NON COTerror = + 3.784 % of span = + 5.676 % T Power COTerror = + (RCA12 + RCA22 + RCA32 +RCA42 + RCA52 + RCA62 + RDTAVG2 + RDT2) 1/2 COTerror = + (0.52 + 0.52 + 0.52 + 0.52 + 0.52 + 0.52 + 1.02 + 1.02) 1/2 COTerror = + 1.871 % of span = + 2.806 % T Power OTT Reactor Trip with (+) FI NON COTerror = [EAnon2 + PMATAVG2 + PMAT2 + PEA2 + (SCARTD +SMTERTD)2 + (SCARTD
+SMTERTD)2 + (SCARTD +SMTERTD)2 + (SCARTD +SMTERTD)2 + (4
- SDRTD2) + STERTD2 + PMAXMTR2
+ (SCAXMTR +SMTEXMTR)2 + SDXMTR2 + STEXMTR2 + FLUX22 + RMTE12 + RMTE22 + RMTE32 +
RMTE42 + RMTE52 + RMTE62 + RTE2]1/2 NON COTerror = [0.002 + 1.702 + 1.302 + 0.002 + (0.417+0.167)2 + (0.417+0.167)2 + (0.417+0.167)2 +
(0.417+0.167)2 + (4
- 0.252) + 0.002 + 0.002 + (0.50+0.404)2 + 0.752 + 2.3192 + 3.802 + 0.6342 + 0.7012
+ 0.2122 + 0.2122 + 0.3002 + 0.2122 + 0.5002]1/2 NON COTerror = + 5.363 % of span = + 8.045 % T Power COTerror = + (RCA12 + RCA22 + RCA32 +RCA42 + RCA52 + RCA62 + RDTAVG2 + RDT2) 1/2 COTerror = + (0.52 + 0.52 + 0.52 + 0.52 + 0.52 + 0.52 + 1.02 + 1.02) 1/2 COTerror = + 1.871 % of span = + 2.806 % T Power
EE-0116 Page 106 of 205 Revision 7 OTT Reactor Trip with (-) FI NON COTerror = [EAnon2 + PMATAVG2 + PMAT2 + PEA2 + (SCARTD +SMTERTD)2 + (SCARTD
+SMTERTD)2 + (SCARTD +SMTERTD)2 + (SCARTD +SMTERTD)2 + (4
- SDRTD2) + STERTD2 + PMAXMTR2
+ (SCAXMTR +SMTEXMTR)2 + SDXMTR2 + STEXMTR2 + FLUX32 + RMTE12 + RMTE22 + RMTE32 +
RMTE42 + RMTE52 + RMTE62 + RTE2]1/2 NON COTerror = [0.002 + 1.702 + 1.302 + 0.002 + (0.417+0.167)2 + (0.417+0.167)2 + (0.417+0.167)2 +
(0.417+0.167)2 + (4
- 0.252) + 0.002 + 0.002 + (0.50+0.404)2 + 0.752 + 2.3192 + 5.402 + 0.6342 + 0.7012
+ 0.2122 + 0.2122 + 0.3002 + 0.2122 + 0.5002]1/2 NON COTerror = + 6.594 % of span = + 9.891 % T Power COTerror = + (RCA12 + RCA22 + RCA32 +RCA42 + RCA52 + RCA62 + RDTAVG2 + RDT2) 1/2 COTerror = + (0.52 + 0.52 + 0.52 + 0.52 + 0.52 + 0.52 + 1.02 + 1.02) 1/2 COTerror = + 1.871 % of span = + 2.806 % T Power See Figure 4.3.5b for specific details associated with the OTT Reactor Trip with no FI.
Revised Time Constants for Equation 4.3.5, Overtemperature T Reactor Trip Equation The installed nominal Lead (1) and Lag (2) Time Constants used for the dynamic compensation associated with TAVG (T) as detailed in Equation 4.3.5 are set for 33 seconds and 4 seconds, respectively.
As stated in Reference 5.71, a lead time constant of 33 seconds and lag time constant of 4 seconds is more conservative than the current Technical Specifications settings of 25 seconds and 3 seconds for 1 and 2, respectively. The actual nominal lead/lag ratio of 33/4 installed in the plant on both units has been shown analytically to provide a faster response (i.e., will cause a reactor trip earlier) than the current Technical Specifications lead/lag ratio of 25/3 for all postulated ramp rates used in the Safety Analysis for the Overtemperature T Reactor Trip Function. The revised Technical Specification limits for 1 and 2 are based on the installed lead and lag settings in the plant, noting the + 10 % of the desired Time Constant tolerance as given by the manufacturer and the Instrument Calibration Procedure (Refs.
5.69 and 5.73). Thus, the revised Technical Specification limit for 1 is 29.7 Seconds (i.e., 33 seconds -
3.3 seconds) and the revised Technical Specification limit for 2 is 4.4 seconds (i.e., 4 seconds + 0.4 seconds). Figure 4.3.5a compares the ramp response of a 29.7/4.4 lead/lag setting versus the current Technical Specifications lead/lag setting of 25/3. The TAVG ramp rate used in Figure 4.3.5a (i.e., + 10 °F
/ Minute) approximates the Surry TAVG response for an Uncontrolled Rod Withdrawal from Full Power terminated by the OTT Reactor Trip for a 0.8 pcm/sec insertion rate as shown in NA&F Calculation SM-932, Figure 14.2-4 (Ref. 5.74). As shown in Figure 4.3.5a, for ramp time < 7 seconds (i.e., time 2 lag time constants), the ramp response of the current Technical Specification lead/lag setting of 25/3 is slightly more conservative than the revised setting of 29.7/4.4. However, after two lag time constants, the output response of the revised Technical Specification lead/lag settings is more conservative and will cause the OTT Reactor Trip to come in sooner than the current settings. Also note that based on
EE-0116 Page 107 of 205 Revision 7 Reference 5.74, there are no Safety Analysis cases that credit the OTT Reactor Trip for event termination times less than 20 seconds.
Lead Lag Response 25/3 vs. 29.7/4.4 TAVG Ramp 25/3 Lead Lag 29.7/4.4 Lead Lag 584.0 582.0 580.0 TAVG (DEG F) 578.0 576.0 574.0 572.0 0 5 10 15 20 25 30 35 Time (Seconds)
Figure 4.3.5a SURRY'S OVERTEM PERATURE DELTA T REACTOR TRIP Analytical Limit (AL)
NON-COT ERRORS 123.20 % Delta T Power 5.676 % DT PWR (TLU) 7.956 % DT Power TOTAL LOOP UNCERTAINTY Maximum Allowable Value (MAV) 2.28 % DT PWR 117.52 % Delta T Power COT ERRORS Maximum Trip Setpoint (MTS) 115.24 % Delta T Power Actual Allowable Value (AV)
SAFETY MARGIN 114.50 % Delta T Power COT ERRORS 3.0 % DT PWR 3.74 % DELTA T POW ER Actual Trip Setpoint (ATS) 111.50 % Delta T Power OPERATING MARGIN 9.50 % DELTA T POW ER High Operating Limit 102.00 % Delta T Power Nominal Operating Limit 100.00 % Delta T Power Figure 4.3.5b
EE-0116 Page 108 of 205 Revision 7 4.3.6 Overpower T Reactor Trip Allowable Value : See below (Refs. 5.1, 5.7, 5.31, 5.69, 5.73, 5.75 & 5.76)
" The channel's maximum Trip Setpoint shall not exceed its computed Trip Setpoint by more than 2.0 % of the T span " (Note that 2.0 % of the T span is equal to 3.0 % T Power)
The Overpower T (OPT) Reactor Trip Setpoint equation in terms of process units is:
Where: (Equation 4.3.6)
T0 = Indicated T at rated thermal power, oF T = Average coolant temperature, oF T = Average coolant temperature measured at nominal conditions and rated power, oF K4 = A constant = 1.089 K5 = 0 for decreasing average temperature A constant, for increasing average temperature 0.02/ oF K6 = 0 for T < T 0.001086 for T > T f(I) = function of I, percent of rated core power as shown in Surry TS Figure 2.3-1.
3 > 9.0 seconds The Overpower T Reactor Trip Setpoint is variable and is constantly calculated based on actual plant conditions. For this reason, the Allowable Value cannot be expressed as a constant. The Overpower T Reactor Trip is a backup reactor trip function and is not credited in the Surry UFSAR Chapter 14 Safety Analysis. However, the FI portion of the Overpower T Reactor Trip is credited in NA&F Calculation SM-0933 (Ref. 5.75) and NA&F Technical Report NE-680 (Ref. 5.76). The FI reset function is used to reduce the Overpower T Reactor Trip setpoint (Surry) and Overtemperature T Reactor Trip setpoint (North Anna and Surry) to compensate for axial power distribution effects. This compensating term, which is a function of I, the axial flux difference, is derived on the basis of a set of bounding non-symmetric axial power distributions. Finally, the time constant for the Overpower T TAVG rate penalty (i.e., 3) is not credited in the Chapter 14 Safety Analysis, Calculation SM-0933 or Technical Report NE-680.
The Allowable Value of 2.0 % of the T span is consistent with the original design basis for this function and is conservative with respect to the CSA Calculation assumptions (Ref. 5.31). The revised Technical Specification Limit for 3 as described in Equation 4.3.6 above will be changed from 10 Seconds to > 9.0 Seconds. The reduction of 1 second from the original 3 time constant of 10 seconds takes into account the + 10 % of the desired Time Constant tolerance as given by the manufacturer and the Instrument Calibration Procedure (Ref. 5.69).
EE-0116 Page 109 of 205 Revision 7 4.3.7 Pressurizer Low Pressure Reactor Trip Allowable Value : > 1875 PSIG (Refs. 5.1, 5.7, 5.32 & 5.68)
Adding the Total Loop Uncertainty (TLU) to the Analytical Limit (AL) yields a Minimum Trip Setpoint (MTS) of 1872.37 PSIG. Adding the NON COT error components to the Analytical Limit yields a Minimum Allowable Value (MAV) of 1869.48 PSIG. The Actual Nominal Trip Setpoint of 1885 PSIG is conservative with respect to the Minimum Trip Setpoint. The current Allowable Value of > 1875 PSIG is conservative with respect to the Minimum Allowable Value. The Nominal Trip Setpoint value of 1885 PSIG allows a 10.00 PSIG margin to be used for the COT error components. The Allowable Value of > 1875 PSIG is approximately equal to the calculated value using the CSA rack error terms from Calculation EE-0514.
The calculated Allowable Value for this function is > 1875.20 PSIG is based on a setpoint of 1885 PSIG using the COT error components. The 0.20 PSIG offset is accommodated in the 12.63 PSIG Safety Margin for this trip as illustrated in Figure 4.3.7.
The statistical combination of the COT and NON COT error components from CSA Calculation EE-0514 (Ref. 5.32) are given below. The COT and NON COT error components are used in Figure 4.3.7 to determine the Minimum Trip Setpoint (MTS) and the Minimum Allowable Value (MAV).
NON COTerror = SE + [PMA2 + PEA2 + (SCA+SMTE)2 + SD2 + SPE2 + STE2 + SPSE2 + M1MTE2 +
M4MTE2 + M5MTE2 + RTE2] 1/2 NON COTerror = 0.0 + [0.02 + 0.02 + 0.9042 + 0.752 + 0.02 + 2.0132 + 0.02 + 0.02 + 0.1502 + 0.2122 +
0.52]1/2 NON COTerror = + 2.398 % of span = + 19.184 PSIG COTerror = + (M12 + M42 + M52 + RD2) 1/2 COTerror = + (0.02 + 0.52 + 0.52 + 1.02) 1/2 COTerror = + 1.225 % of span = + 9.800 PSIG See Figure 4.3.7 for specific details.
EE-0116 Page 110 of 205 Revision 7 SURRY'S PRESSURIZER LOW PRESSURE REACTOR TRIP Nominal Operating Limit 2235 PSIG Low Operating Limit 2210 PSIG OPERATING MARGIN 325 PSIG (Static)
Actual Trip Setpoint (ATS) 1885 PSIG COT ERRORS 10.00 PSIG SAFETY MARGIN 12.63 PSIG (Static)
Actual Allowable Value (AV) 1875.00 PSIG Minimum Trip Setpoint (MTS) 1872.37 PSIG 2.888 PSIG COT ERRORS TOTAL LOOP 22.072 PSIG Minimum Allowable Value (MAV) 1869.48 PSIG UNCERTAINTY (TLU)
NON-COT ERRORS 19.184 PSIG Analytical Limit (AL) 1850.3 PSIG Figure 4.3.7 4.3.8 Pressurizer High Pressure Reactor Trip Allowable Value : < 2380 PSIG (Refs. 5.1, 5.7, 5.32 & 5.68)
Subtracting the Total Loop Uncertainty (TLU) from the Analytical Limit (AL) yields a Maximum Trip Setpoint (MTS) of 2388.98 PSIG. Subtracting the NON COT error components from the Analytical Limit yields a Maximum Allowable Value (MAV) of 2391.20 PSIG. The Actual Nominal Trip Setpoint of 2370 PSIG is conservative with respect to the Maximum Trip Setpoint. The current Actual Allowable Value of < 2385 PSIG is conservative with respect to the Maximum Allowable Value. The current Allowable Value < 2385 PSIG will be changed to < 2380 PSIG to conform to the requirements of Methods 1 and 2 as described in Sections 3.3.1 and 3.3.2. This is based on the Nominal Trip Setpoint value of 2370.0 PSIG. The Nominal Trip Setpoint value of 2370 PSIG will allow a 10.0 PSIG margin to
EE-0116 Page 111 of 205 Revision 7 be used for the COT error components. The Allowable Value of < 2380 PSIG is sufficiently close enough to the calculated value using the CSA rack error terms from Calculation EE-0514 (Ref 5.32).
The calculated Allowable Value for this function is < 2378.94 PSIG. The 1.06 PSIG offset is accommodated in the 18.98 PSIG Safety Margin for this trip as illustrated in Figure 4.3.8.
In this case, the current Allowable Value of < 2385.0 PSIG will be changed to < 2380.0.
The statistical combination of the COT and NON COT error components from CSA Calculation EE-0514 (Ref. 5.32) are given below. The COT and NON COT error components are used in Figure 4.3.8 to determine the Maximum Trip Setpoint (MTS) and the Maximum Allowable Value (MAV).
NON COTerror = SE + [PMA2 + PEA2 + (SCA+SMTE)2 + SD2 + SPE2 + STE2 + SPSE2 + M1MTE2 +
M4MTE2 + RTE2]1/2 NON COTerror = 0.0 + [0.02 + 0.02 + 0.9042 + 0.752 + 0.02 + 2.0132 + 0.02 + 0.02 + 0.152 + 0.52 +]1/2 NON COTerror = + 2.388 % of span = + 19.104 PSIG COTerror = + (M12 + M42 + RD2) 1/2 COTerror = + (0.02 + 0.52 + 1.02) 1/2 COTerror = + 1.118 % of span = + 8.944 PSIG See Figure 4.3.8 for specific details.
EE-0116 Page 112 of 205 Revision 7 SURRY'S PRESSURIZER HIGH PRESSURE REACTOR TRIP Analytical Limit (AL) 2410.3 PSIG COT ERRORS NON-COT ERRORS 19.104 PSIG TOTAL LOOP 21.32 PSIG Maximum Allowable Value (MAV)
UNCERTAINTY (TLU) 2391.20 2.216 PSIG Maximum Trip Setpoint (MTS) 2388.98 PSIG Actual Allowable Value (AV) 2380.00 PSIG COT ERRORS SAFETY MARGIN 10.00 PSIG 18.98 PSIG Actual Trip Setpoint (ATS) 2370 PSIG OPERATING MARGIN 110 PSIG High Operating Limit 2260 PSIG Nominal Operating Setpoint 2235 PSIG Figure 4.3.8
EE-0116 Page 113 of 205 Revision 7 4.3.9 Reactor Coolant Flow Low Reactor Trip Allowable Value : > 91.0 % Flow (Normalized) (Refs. 5.1, 5.7, 5.34 & 5.66)
Adding the Total Loop Uncertainty (TLU) to the Analytical Limit (AL) yields a Minimum Trip Setpoint (MTS) of 89.93 % Flow. Adding the NON COT error components to the Analytical Limit yields a Minimum Allowable Value (MAV) of 89.63 % Flow. The current Nominal Trip Setpoint of 92.0 %
Flow is conservative with respect to the Minimum Trip Setpoint and the Actual Allowable Value of >
90.0 % Flow is conservative with respect to the Minimum Allowable Value. The current Allowable Value of > 90.0 % Flow is non-conservative with respect to the calculated value using the CSA rack error terms from Calculation EE-0183 (Ref 5.34). The current Allowable Value of > 90.0 % Flow will be changed to > 91.0 % Flow to conform to the methodology described in Sections 3.3.1 and 3.3.2.
The calculated Allowable Value for this function is > 90.738 % Flow. The 0.262 % Flow offset is accommodated in the 2.067 % Flow Safety Margin for this trip as illustrated in Figure 4.3.9.
The statistical combination of the COT and NON COT error components from CSA Calculation EE-0183 (Ref. 5.34) are given below. The COT and NON COT error components are used in Figure 4.3.9 to determine the Minimum Trip Setpoint (MTS) and the Minimum Allowable Value (MAV).
NON COTerror (P span) = [(SCA+SMTE)2 + SD2 + SPE2 + STE2 + M6MTE2] 1/2 NON COTerror (P span) = [(0.50+0.169)2 + 0.3572 + 0.02 + 1.2882 + 0.1142]1/2 NON COTerror (P span) = + 1.499 % of P span = + 0.978 % of Flow span @ 92 % Flow NON COTerror (Flow span) = (PMA2 + PEA2 + RTE2) 1/2 NON COTerror (Flow span) = (1.9002 + 0.02 + 0.52) 1/2 NON COTerror (Flow span) = 1.965 % of Flow span TOTAL NON COTerror (Flow span) = (1.9652 + 0.9782) 1/2 = 2.195 % of Flow span = 2.634 % Flow @
92.0 % Flow (e.g., the Nominal Trip Setpoint).
COTerror (P span ) = + (M62) 1/2 COTerror (P span ) = + (0.52) 1/2 COTerror (P span) = + 0.50 % of P span = + 0.326 % of Flow span @ 92 % Flow COTerror (Flow span) = RD = 1.0 % of Flow span TOTAL COTerror (Flow span) = (0.3262 + 1.02) 1/2
= 1.052 % of Flow span = 1.262 % Flow @ 92.0 %
Flow (e.g., the Nominal trip Setpoint).
EE-0116 Page 114 of 205 Revision 7 See Figure 4.3.9 for specific details.
SURRY'S LOW REACTOR COOLANT FLOW REACTOR TRIP Nominal Operating Limit 100 % Flow Low Operating Limit 98.0 % Flow OPERATING MARGIN 6.0 % Flow Actual Trip Setpoint (ATS) 92.0 % Flow COT ERRORS 1.00 % Flow SAFETY MARGIN 2.067 % Flow Actual Allowable Value (AV) 91.0 % Flow Minimum Trip Setpoint (MTS) 89.93 % Flow COT ERRORS 0.299 %
TOTAL LOOP Flow 2.933 % Flow Minimum Allowable Value (MAV)
UNCERTAINTY (TLU) 89.634 % Flow NON-COT ERRORS 2.634 % Flow Analytical Limit (AL) 87.0 % Flow Figure 4.3.9 4.3.10 Reactor Coolant Pump Undervoltage Allowable Value : This Allowable Value will be provided by Corporate Electrical EE Power.
4.3.11 Reactor Coolant Pump Underfrequency Allowable Value : This Allowable Value will be provided by Corporate Electrical EE Power.
EE-0116 Page 115 of 205 Revision 7 4.3.12 Pressurizer High Level Reactor Trip Allowable Value : < 89.12 % Level (Hot) (Refs. 5.1, 5.7, 5.33, 5.67 & 5.87)
The analysis for Surrys Pressurizer High Level Reactor Trip was performed in Section 3.4.3 and the specific details are illustrated in Figure 3.4.3.b.
Note: According to Technical Specification 2.3 Basis, 1154 ft3 is equal to 92 % of level span. The revised LSSS is equal to 89.12 % of level span. According to Technical Report NE-1381, Revision 0, Page 12, 1.0 % level in the Pressurizer is equal to 74.0 gallons and 1 gallon is equal to 0.13368 ft3. Then 92 % - 89.12 % = 2.88 % level span. So 2.88 %
level span
- 74 gallons per % span = 213.12 gallons, taking 213.12 gallons
- 0.13368 ft3 per gallon = 28.49 ft3.
Subtracting this volume of 28.49 ft3 from the original volume of 1154 ft3 yields a new volume of 1125.5 ft3 at 89.12
% level.
4.3.13 Steam Generator Water Level Low Low Reactor Trip/SI Allowable Value : > 16.0 % Narrow Range (NR) Level (Refs. 5.1, 5.7, 5.35 & 5.60)
The analysis for Steam Generator Water Level Low Low Reactor Trip will be based on HARSH/DBE Conditions which will bound both the Reactor Trip and ESFAS Initiation Functions. Adding the Total Loop Uncertainty (TLU) to the Analytical Limit (AL) yields a Minimum Trip Setpoint (MTS) of 14.764
% NR Level. Adding the NON COT error components to the Analytical Limit yields a Minimum Allowable Value (MAV) of 14.426 % NR Level. The Actual Nominal Trip Setpoint of 17.0 % NR Level is conservative with respect to the Minimum Trip Setpoint and the Actual Allowable Value of >
14.5 % NR Level is non-conservative with respect to the Minimum Allowable Value. In this case, the current Allowable Value of > 14.5 % NR Level will be changed to > 16.0 % NR Level to meet the requirements of Methods 1 and 2 as discussed in Sections 3.3.1 and 3.3.2. In addition, the new Allowable Value is conservative with respect to the calculated value using the CSA rack error terms from Calculation EE-0432 (Ref 5.35). This Allowable Value of > 16.0 % NR Level is based on maintaining a Nominal Trip Setpoint value of 17.0 % NR Level.
The statistical combination of the COT and NON COT error components from CSA Calculation EE-0432 (Ref. 5.35) are given below. The COT and NON COT error components are used in Figure 4.3.13 to determine the Minimum Trip Setpoint (MTS) and the Minimum Allowable Value (MAV).
NON COTerror = PMADBE + IR + SPTE + REDBE + (PEA2 + (SCA+SMTE)2 + SD2 + SPE2 + STE2 +
M1MTE2 + M3MTE2 + RTE2) 1/2 NON COTerror = 8.75 + 0.265 +3.510 + 0.0 + [0.02 + (0.5+0.361)2 + 0.2812 + 1.1582 + 1.0872 + 0.02 +
0.1502 + 0.52]1/2 NON COTerror = + 14.426 % of span = + 14.426 % NR Level (worst case).
COTerror = + (M12 + M32 + RD2) 1/2 COTerror = + (0.02 + 0.52 + 1.02) 1/2 COTerror = + 1.118 % of span = + 1.118 % NR level
EE-0116 Page 116 of 205 Revision 7 See Figure 4.3.13 for specific details.
SURRY'S STEAM GENERATOR LO-2 LEVEL REACTOR TRIP / ESFAS INITIATION Nominal Operating Limit 44.0 % NR Level Low Operating Limit 39.0 % NR Level OPERATING MARGIN 22.0 % NR Level Actual Trip Setpoint (ATS) 17.0 % NR Level COT ERRORS 1.00 % NR Level SAFETY MARGIN 2.236 % NR Level Actual Allowable Value (AV) 16.00 % NR Level Minimum Trip Setpoint (MTS) 0.338 % NR Level 14.426 % NR Level 14.764 % NR Level COT ERRORS TOTAL LOOP 14.764 % NR Level Minimum Allowable Value (MAV) 14.426 % NR Level UNCERTAINTY (TLU)
NON-COT ERRORS Analytical Limit (AL) 0.0 % NR Level (DBE)
Figure 4.3.13 4.3.14 Steam Generator Water Level Low Coincident Reactor Trip Allowable Value : > 19.0 % Narrow Range (NR) Level (Refs. 5.1, 5.7, 5.35 & 5.60)
In this case, the current value of > 15.0 % NR Level will be changed to > 19.0 % to ensure it is conservative with respect to the calculated value of the CSA rack error terms from Calculation EE-0432 (Ref 5.35). The Steam Generator Water Level Low Coincident Reactor Trip is a backup reactor trip function and is not credited in the UFSAR Chapter 14 Safety Analysis.
The current Allowable Value > 15.0 % NR Level will be changed to > 19.0 % NR Level to conform to the requirements of Methods 1 and 2 as described in Sections 3.3.1 and 3.3.2. This Allowable Value of
> 19.0 % NR Level is based on maintaining a Nominal Trip Setpoint value of 20.0 % Level.
EE-0116 Page 117 of 205 Revision 7 4.3.15 Steam Flow Feed Flow Mismatch Coincident Reactor Trip Allowable Value : < 1.0
- 106 lbs/hr (i.e., nominal steam flow at RTP = 3.7533
- 106 lbs/hr)
(Refs. 5.1, 5.7 & 5.36)
This Allowable Value of < 1.0
- 106 lbs/hr is based on maintaining a Nominal Trip Setpoint value of 0.709
- 106 lbs/hr. In this case, the current Allowable Value of < 1.0
- 106 lbs/hr is equal to 26.64 % of nominal steam flow at RTP (i.e., Flownom). The current Allowable Value will be retained because it is conservative with respect to the calculated value based on the CSA rack error terms from Calculation EE-0355 (Ref 5.36). In addition, the current Allowable Value is conservative with respect to the nominal value used in later versions of Technical Specifications (i.e., 40.0 % of nominal flow at RTP).
The Steam Flow Feed Flow Mismatch Coincident Reactor Trip is a backup reactor trip function and is not credited in the Surry UFSAR Chapter 14 Safety Analysis.
4.3.16 Safety Injection (SI) Input from Engineered Safety Features Actuation System (ESFAS)
See Section 4.4.
Reactor Trip Permissives Note: In the context of this document, the terms Allowable Value and Setting Limit and Limiting Safety System Setting (LSSS) have the same meaning and intent.
4.3.17 Permissive P-6, Intermediate Range Neutron Flux Allowable Value : The source range high flux, high setpoint trip shall be unblocked prior to or when the intermediate range nuclear flux decreases to 5 *10-11 Amps (Refs. 5.1, 5.7, 5.29 & 5.57)
This Allowable Value of 5 *10-11 Amps is based on maintaining a Nominal Trip Setpoint of 1 *10-10 Amps (1). In this case, the current Allowable Value of 5 *10-11 Amps will be retained because it is equal to the calibration accuracy of the device. Note that this function is assumed to be available in the UFSAR Chapter 14 Safety Analysis but no specific setpoint is assumed (Ref 5.1).
(1) The inequality signs have been removed from the text in order to clarify the actual operation of the unblock portion of the permissive function.
EE-0116 Page 118 of 205 Revision 7 4.3.18 Permissive P-7, Block Low Power Reactor Trips Allowable Value : The reactor trip on low pressurizer pressure, high pressurizer level, turbine trip, and low reactor coolant flow for two or more loops shall be unblocked prior to or when power increases to 11 % of rated power.
(Refs. 5.1, 5.8, 5.28, 5.38 & 5.139)
Permissive P-7 is made up of input signals from Turbine First Stage Pressure and NIS Power Range.
Signals to the P-7 and P-10 permissives are supplied from the same bistables in the NIS Power Range drawers. P-7 and P-10 will both enable and block functions from the trip and reset points of these bistables. The calibration procedures for the NIS Power Range bistables set the nominal trip setpoints associated with the two permissives such that they will trip whenever the measured reactor power level reaches 10 % power (increasing). The P-7 input from Turbine First Stage Pressure is currently set to trip at 10.0 % Turbine Load (increasing). When two out of four of the NIS Power Range channels trip or if one of the two Turbine First Stage Pressure channels trip the following occurs:
- Permissive P-7 allows reactor trip on the following: low flow, reactor coolant pump breakers open in more than one loop, undervoltage (RCP busses), underfrequency (RCP) busses, turbine trip, pressurizer low pressure, and pressurizer high level.
- Permissive P-10 allows manual block of intermediate range reactor trip, allows manual block of power range (low setpoint) reactor trip, allows manual block of intermediate range rod stop (P-1), and automatically blocks source range reactor trip (P-6) and provides an input to P-7.
The trip and reset of a bistable cannot be the same point. It is physically not possible. There must be a deadband between the trip and reset points. The calibration procedures for the NIS Power Range bistables set the nominal reset points for the two permissives such that they reset whenever the measured reactor power level reaches 8% power (decreasing). The P-7 input from Turbine First Stage Pressure is set to reset at 10 % Turbine Load (decreasing). When three out of four of the NIS Power Range channels reset and if two out of the two Turbine First Stage Pressure channels reset the following occurs:
- Permissive P-7 blocks reactor trip on the following: low flow, reactor coolant pump breakers open in more than one loop, undervoltage, underfrequency, turbine trip, pressurizer low pressure, and pressurizer high level.
There is no specific Safety Analysis Limit associated with Permissive P-7. However, Permissive P-7 is Assumed Available by Nuclear Analysis and Fuel. Since P-7 is a permissive for functions with Safety Analysis Limits, for conservatism, it will be treated as if it had a Limiting Safety System Setting. In order to account for instrumentation (COT) errors, 1% of reactor power will be added to the P-7 safety function.
This results in a Limiting Safety System Setting for the P-7 enable interlock of 11% of reactor power (i.e.,
Turbine Load). The Trip Setpoint for the Turbine First Stage Pressure Inputs to Permissive P-7 has been changed to 10.0 % Turbine Load (increasing) and the Reset Setpoint will be changed to 8.8 % Turbine Load (decreasing) (Ref. 5.139).
EE-0116 Page 119 of 205 Revision 7 4.3.19 Permissive P-8, Power Range Neutron Flux Allowable Value : The single loop loss of flow reactor trip shall be unblocked prior to or when the power range nuclear flux increases to 37.0 % of rated power.
(Refs. 5.1, 5.7, 5.28 & 5.82)
Subtracting the Total Loop Uncertainty (TLU) from the Analytical Limit (AL) yields a Maximum Trip Setpoint (MTS) of 52.48 % Rated Thermal Power (RTP). Subtracting the NON COT error components from the Analytical Limit yields a Maximum Allowable Value (MAV) of 53.08 % RTP. The Actual Nominal Trip Setpoint of 35.0 % RTP is conservative with respect to the Maximum Trip Setpoint and the current Allowable Value of 50.0 % RTP is conservative with respect to the Maximum Allowable Value (1). The current Allowable Value of 50.0 % RTP will be changed to 37.0 % RTP to conform to the requirements of Methods 1 and 2 as described in Sections 3.3.1 and 3.3.2. The revised Allowable Value of 37.0 % RTP is conservative with respect to the Maximum Allowable Value but is non-conservative with respect to the calculated Allowable Value using the CSA rack error terms from Calculation EE-0198 (Ref. 5.28). The calculated Allowable Value for this function is 36.70 % RTP. The 0.3 % RTP offset is accommodated in the 17.48 % RTP Safety Margin for this trip as illustrated in Figure 4.3.19.
This Allowable Value of 37.0 % RTP is based on maintaining a Nominal Trip Setpoint value of 35.0 %
RTP.
The statistical combination of the COT and NON COT error components from CSA Calculation EE-0198 (Ref. 5.28) are given below. The COT and NON COT error components are used in Figure 4.3.19 to determine the Maximum Trip Setpoint (MTS) and the Maximum Allowable Value (MAV).
NON COTerror = SE + (PMA12 + PMA22 + RMTE2 + RTE2) 1/2 NON COTerror = 0.0 + (2.02 + 5.02 + 2.02 + 0.52) 1/2 NON COTerror = + 5.766 % of span = + 6.919 % RTP COTerror = + (RCA2 + RD2) 1/2 COTerror = + (1.02 + 1.02) 1/2 COTerror = + 1.414 % of span = + 1.697 % RTP See Figure 4.3.19 for specific details.
(1) The inequality signs have been removed from the text in order to clarify the actual operation of the unblock portion of the permissive function.
EE-0116 Page 120 of 205 Revision 7 SURRY'S POWER RANGE REACTOR TRIP PERMISSIVE P-8 Analytical Limit (AL) 60.00 % RTP COT ERRORS NON-COT ERRORS 6.919 % RTP TOTAL LOOP 7.518 % RTP UNCERTAINTY (TLU)
Maximum Allowable Value (MAV) 53.08 % RTP 0.599 % RTP Maximum Trip Setpoint (MTS) 52.48 % RTP Actual Allowable Value (AV) 37.00 % RTP COT ERRORS SAFETY MARGIN 2.00 % RTP 17.48 % RTP Actual Trip Setpoint (ATS) 35.00 % RTP OPERATING MARGIN 19.00 % RTP High Operating Limit 11.00 % RTP Nominal Operating Setpoint 10.00 % RTP Figure 4.3.19
EE-0116 Page 121 of 205 Revision 7 4.3.20 Permissive P-10, Power Range Neutron Flux Allowable Values : The power range high flux, low setpoint trip and the intermediate range high flux, high setpoint trip shall be unblocked prior to or when power decreases to 7.0 % of rated power. (Refs. 5.1, 5.7 & 5.82)
Signals to the P-10 permissive are supplied from bistables in the NIS Power Range drawers. The P-10 permissive enables and blocks functions based on the trip and reset points of the bistable. The calibration procedures for the NIS Power Range bistables set the nominal trip setpoint such that it will trip whenever the measured reactor power level reaches 10 % power (increasing). When two out of four of these channels trip the following occurs:
- Permissive P-10: enables manual block of intermediate range reactor trip, allows manual block of power range (low setpoint) reactor trip, allows manual block of intermediate range rod stop (P-1),
and automatically blocks source range reactor trip (P-6).
- These bistables also provide one of two inputs to Permissive P-7 to enable certain at power reactor trips (see section 4.3.18 for Permissive P-7).
The calibration procedures for the NIS Power Range bistables set the nominal reset point for Permissive P-10 such that it is reset whenever the measured reactor power level reaches 8 % power (decreasing).
When three out of four of these channels reset the following occurs:
- Permissive P-10: defeats the manual block of the intermediate range reactor trip, defeats the manual block of power range (low setpoint) reactor trip, and defeats the manual block of intermediate range rod stop.
- These bistables also provide one of two inputs to Permissive P-7 to block certain at power trips (see section 4.3.18 for Permissive P-7)
There is no specific Safety Analysis Limit associated with Permissive P-10. However, it is Assumed Available by Nuclear Analysis and Fuel. Since P-10 is a permissive for functions with Safety Analysis Limits and provides an input for Permissive P-7, for conservatism, it will be treated as if it had an Allowable Value. In order to account for instrumentation (COT) errors, 1 % of reactor power is added to the P-10 safety function. The power range high flux, low setpoint trip and the intermediate range high flux, high setpoint trip shall be unblocked prior to and when power decreases to 7 % of rated power. This results in an Allowable Value for the P-10 (defeat block) interlock of 7.0 % of RTP.
This Allowable Value of 7.0 % RTP is based on maintaining a Nominal Reset value of 8.0 % RTP decreasing. The revised Allowable Value of 7.0 % RTP is conservative with respect to the calculated value using the CSA rack error terms from Calculation EE-0198 (Ref 5.28).
EE-0116 Page 122 of 205 Revision 7 4.4 Setting Limits for Surry Power Station Custom Technical Specifications, Table 3.7-4, Engineered Safety Features Actuation System Instrumentation Setting Limits and Table 3.7-2, Engineered Safety Features Actuation System Instrumentation Operating Conditions Note: In the context of this document, the terms Allowable Value, Setting Limit and Limiting Safety System Setting (LSSS) have the same meaning and intent.
4.4.1 Safety Injection, Manual Initiation Allowable Value : N/A There is no specific ESFAS Trip Setpoint associated with this function.
4.4.2 Containment Pressure - High Allowable Value : < 18.5 PSIA (Refs. 5.1, 5.7, 5.39 & 5.61)
Subtracting the Total Loop Uncertainty (TLU) from the Analytical Limit (AL) yields a Maximum Trip Setpoint (MTS) of 18.463 PSIA. Subtracting the NON COT error components from the Analytical Limit yields a Maximum Allowable Value (MAV) of 18.731 PSIA. The Actual Nominal Trip Setpoint of 17.7 PSIA is conservative with respect to the Maximum Trip Setpoint and the Actual Allowable Value of < 19.0 PSIA is non-conservative with respect to the Maximum Allowable Value. The current Allowable Value of < 19.0 PSIA will be changed to < 18.5 PSIA to conform to the requirements of Methods 1 and 2 as described in Sections 3.3.1 and 3.3.2. The revised Allowable Value of < 18.5 PSIA is based on maintaining a Nominal Trip Setpoint value of 17.7 PSIA.
The statistical combination of the COT and NON COT error components from CSA Calculation EE-0131 (Ref. 5.39) are given below. The COT and NON COT error components are used in Figure 4.4.2 to determine the Maximum Trip Setpoint (MTS) and the Maximum Allowable Value (MAV).
NON COTerror = [PMA2 + PEA2 + (SCA+SMTE)2 + SD2 + STE2 + SPE2 + SPSE2 + M1MTE2 +
M4MTE2 + RTE2] 1/2 NON COTerror = [0.02 + 0.02 + (0.5+0.215)2 + 0.3082 + 1.1582 + 0.02 + 0.02 + 0.02 + 0.1502 + 0.52] 1/2 NON COTerror = + 1.490 % of span = + 0.969 PSIA COTerror = + (M12 + M42 + RD2) 1/2 COTerror = + (0.02 + 0.52 + 1.02) 1/2 COTerror = + 1.118 % of span = + 0.727 PSIA See Figure 4.4.2 for specific details.
EE-0116 Page 123 of 205 Revision 7 SURRY'S CONTAINMENT PRESSURE HI-1 ESFAS INITIATION Analytical Limit (AL) 19.7 PSIA COT ERRORS NON-COT ERRORS 0.969 PSIA TOTAL LOOP 1.237 PSIA Maximum Allowable Value (MAV)
UNCERTAINTY (TLU) 18.731 PSIA 0.268 PSIA Actual Allowable Value (AV) 18.50 PSIA Maximum Trip Setpoint (MTS) 18.463 PSIA COT ERRORS SAFETY MARGIN 0.80 PSIA 0.763 PSIA Actual Trip Setpoint (ATS) 17.7 PSIA OPERATING MARGIN 5.7 PSIA High Operating Limit 12.0 PSIA Nominal Operating Limit 10.5 PSIA Figure 4.4.2 4.4.3 Containment Pressure High - High Allowable Value : < 24.00 PSIA (Refs. 5.1, 5.7, 5.39 & 5.61)
Subtracting the Total Loop Uncertainty (TLU) from the Analytical Limit (AL) yields a Maximum Trip Setpoint (MTS) of 25.763 PSIA. Subtracting the NON COT error components from the Analytical Limit yields a Maximum Allowable Value (MAV) of 26.031 PSIA. The Actual Nominal Trip Setpoint of 23.00 PSIA is conservative with respect to the Maximum Trip Setpoint and the Actual Allowable Value of < 25.00 PSIA is conservative with respect to the Maximum Allowable Value. The Allowable Value of < 25.00 PSIA will be changed to < 24.00 PSIA to conform to the requirements of Methods 1 and 2 as described in Sections 3.3.1 and 3.3.2. The revised allowable value of < 24.00 PSIA is conservative with respect to the calculated Maximum Allowable Value but is non-conservative with respect to the calculated Allowable Value using the CSA rack error terms from Calculation EE-0131 (Ref. 5.39). The calculated Allowable Value for this function is < 23.727 PSIA. The 0.273 PSIA offset is accommodated in the 2.763 PSIA Safety Margin for this function as illustrated in Figure 4.4.3. The statistical
EE-0116 Page 124 of 205 Revision 7 combination of the COT and NON COT error components from CSA Calculation EE-0131 (Ref. 5.39) are given below. The COT and NON COT error components are used in Figure 4.4.3 to determine the Maximum Trip Setpoint (MTS) and the Maximum Allowable Value (MAV).
NON COTerror = (PMA2 + PEA2 + (SCA+SMTE)2 + SD2 + SPE2 + STE2 + SPSE2 + M1MTE2 +
M4MTE2 + RTE2) 1/2 NON COTerror = [0.02 + 0.02 + (0.5+0.215)2 + 0.3082 + 1.1582 + 0.02 + 0.02 + 0.02 + 0.1502 + 0.52) 1/2 NON COTerror = + 1.490 % of span = + 0.969 PSIA COTerror = + (M12 + M42 + RD2) 1/2 COTerror = + (0.02 + 0.52 + 1.02) 1/2 COTerror = + 1.118 % of span = + 0.727 PSIA SURRY'S CONTAINMENT PRESSURE HI-HI ESFAS INITIATION Analytical Limit (AL) 27.0 PSIA NON-COT ERRORS 0.969 psia TOTAL LOOP 1.237 PSIA Maximum Allowable Value (MAV)
UNCERTAINTY (TLU) 26.031 PSIA COT ERRORS 0.268 PSIA Maximum Trip Setpoint (MTS) 25.763 PSIA Actual Allowable Value (AV) 24.00 PSIA COT ERRORS SAFETY MARGIN 1.00 PSIA 2.763 PSIA Actual Trip Setpoint (ATS) 23.00 PSIA OPERATING MARGIN 11.0 PSIA High Operating Limit 12.0 PSIA Nominal Operating Setpoint 10.5 PSIA Figure 4.4.3
EE-0116 Page 125 of 205 Revision 7 4.4.4 Pressurizer Pressure Low-Low Allowable Value : > 1770 PSIG (Refs. 5.1, 5.8, 5.32 & 5.68)
Adding the Total Loop Uncertainty (TLU) to the Analytical Limit (AL) yields a Minimum Trip Setpoint (MTS) of 1771.06 PSIG. Adding the NON COT error components to the Analytical Limit yields a Minimum Allowable Value (MAV) of 1770.40 PSIG. The Actual Nominal Trip Setpoint of 1780 PSIG is conservative with respect to the Minimum Trip Setpoint and the Actual Allowable Value of 1770 PSIG is conservative with respect to the Minimum Allowable Value. The Nominal Trip Setpoint value of 1780 PSIG allows a 10.00 PSIG margin to be used for the COT error components. The Allowable Value of > 1770 PSIG is conservative with respect to the calculated Minimum Allowable Value but is non-conservative with respect to the calculated Allowable Value using the CSA rack error terms from Calculation EE-0514.
The calculated Allowable Value for this function is > 1771.056 PSIG based on the a setpoint of 1780 PSIG using the COT error components. The 1.056 PSIG offset is accommodated in the 8.94 PSIG Safety Margin for this trip as illustrated in Figure 4.4.4.
The statistical combination of the COT and NON COT error components from CSA Calculation EE-0514 (Ref. 5.32) are given below. The COT and NON COT error components are used in Figure 4.4.4 to determine the Minimum Trip Setpoint (MTS) and the Minimum Allowable Value (MAV).
NON COTerror = SE + IR + [PMA2 + SPTE2 + REDBE2 + PEA2 + (SCA+SMTE)2 + SD2 + SPE2 + STE2
+ SPSE2 + M1MTE2 + M4MTE2 + RTE2]1/2 NON COTerror = 0.0 + .245 + [0.02 + 8.02 + 1.6882 + 0.02 + (0.5 + 0.404)2 + 0.752 + 0.02 + 2.0132 + 0.02
+ 0.02 + 0.152 + 0.52]1/2 NON COTerror = - 8.273 % or + 8.763 % of span = + 70.104 PSIG (worst case)
COTerror = + (M12 + M42 + RD2) 1/2 COTerror = + (0 + 0.52 + 1.02) 1/2 COTerror = + 1.118 % of span = + 8.944 PSIG See Figure 4.4.4 for specific details.
EE-0116 Page 126 of 205 Revision 7 SURRY'S PRESSURIZER LO-LO PRESSURE ESFAS INITIATION Nominal Operating Limit 2235 PSIG Low Operating Limit 2210 PSIG OPERATING MARGIN 430 PSIG Actual Trip Setpoint (ATS) 1780 PSIG COT ERRORS 10.0 PSIG SAFETY MARGIN 8.94 PSIG (Static)
Minimum Trip Setpoint (MTS) 1771.06 PSIG Actual Allowable Value (AV) 0.66 PSIG 1770 PSIG COT TOTAL LOOP ERRORS 70.760 PSIG Minimum Allowable Value (MAV) 1770.40 PSIG UNCERTAINTY (TLU)
NON-COT ERRORS 70.10 PSIG Analytical Limit (AL) 1700.3 PSIG Figure 4.4.4 4.4.5 High Differential Pressure Steam Lines Versus Steam Header ESFAS Initiation Allowable Value : < 135.0 PSID (Refs. 5.1, 5.7, 5.36 & 5.65)
Subtracting the Total Loop Uncertainty (TLU) from the Analytical Limit (AL) yields a Maximum Trip Setpoint (MTS) of 130.63 PSID. Subtracting the NON COT error components from the Analytical Limit yields a Maximum Allowable Value (MAV) of 135.60 PSID. The Actual Nominal Trip Setpoint of 120.0 PSID is conservative with respect to the Maximum Trip Setpoint. However, the current Allowable Value of < 150.0 PSID is non-conservative with respect to the Maximum Allowable Value. The current Allowable Value will be changed from < 150.0 PSID to < 135.0 PSID in order to conform to the requirements of Methods 1 and 2 as described in Sections 3.3.1 and 3.3.2. The revised Allowable Value
EE-0116 Page 127 of 205 Revision 7 of < 135.0 PSID is based on maintaining a Nominal Trip Setpoint value of 120.0 PSID. The revised Allowable Value of < 135.0 PSID is conservative with respect to the calculated COTerror shown below.
The statistical combination of the COT and NON COT error components from CSA Calculation EE-0355 (Ref. 5.36) are given below. The COT and NON COT error components are used in Figure 4.4.5 to determine the Maximum Trip Setpoint (MTS) and the Maximum Allowable Value (MAV).
NON COTerror csa 7 = [EA 2 + PMA2 + PEA2 + (SCA+SMTE)2 + SD2 + SPE2 + STE2 + SPSE2 +
M10MTE2] 1/2 NON COTerror csa7 = [0.02 + 0.02 + 0.02 + (0.5 + 0.207)2 + 0.4292 + 0.02 + 1.4752 + 0.02 + 0.02] 1/2 NON COTerror csa7 = + 1.691 % of span = + 23.674 PSID NON COTerror csa 14 = [EA 2 + PMA2 + PEA2 + (SCA+SMTE)2 + SD2 + SPE2 + STE2 + SPSE2 +
M17MTE2 + M18MTE2] 1/2 NON COTerror csa14 = [0.02 + 0.02 + 0.02 + (0.5+0.207)2 + 0.4292 + 0.02 + 1.4752 + 0.02 + 0.02 + 0.1582]
1/2 NON COTerror csa14 = + 1.698 % of span = + 23.772 PSID NON COTerror r4 = (M19MTE2 + RTE2) 1/2 NON COTerror r4 = [0.2122 + 0.52) 1/2 NON COTerror r4 = + 0.543 % of span = + 7.602 PSID TOTAL NON COTerror = (NON COTerror csa72 + NON COTerror csa 142 + NON COTerror r42)1/2 TOTAL NON COTerror = (1.6912 + 1.6982 + 0.5432) 1/2 TOTAL NON COTeror = 2.457 % of span = + 34.40 PSID COTerror = + (M102 + M172 + M182 + M192 + RD2) 1/2 COTerror = + (0.02 + 0.02 + 0.52 + 0.52 + 1.02) 1/2 COTerror = + 1.225 % of span = + 17.15 PSID See Figure 4.4.5 for specific details.
EE-0116 Page 128 of 205 Revision 7 SURRY'S HI dP STM LINE VS STM HDR ESFAS INITIATION Analytical Limit (AL) 170.0 PSID NON-COT ERRORS TOTAL LOOP 34.40 PSID 39.37 PSID Maximum Allowable Value (MAV)
UNCERTAINTY (TLU) 135.60 PSID Actual Allowable Value (AV)
COT ERRORS 135.0 PSID 4.97 PSIA Maximum Trip Setpoint (MTS) 130.63 PSID COT ERRORS 15.0 PSID SAFETY MARGIN 10.63 PSID Actual Trip Setpoint (ATS) 120.00 PSID OPERATING MARGIN 100.00 PSID High Operating Limit 20.0 PSID Nominal Operating Limit 0.0 PSID Figure 4.4.5
EE-0116 Page 129 of 205 Revision 7 4.4.6 High Steam Flow in 2/3 Steam Lines Allowable Values : < 40.0 % of full steam flow (at zero load), < 40.0 % of full steam flow (at 20 % load) and < 110.0 % of full steam flow (at full load)
(Refs. 5.1, 5.7, 5.12, 5.38 & 5.62)
Subtracting the Total Loop Uncertainty (TLU = 2.933 % of P span) from the Analytical Limit (AL =
20.76 % of P span from 0 % to 20 % power, the most limiting condition) yields a Maximum Trip Setpoint (MTS) of 17.827 % of P span. Subtracting the NON COT error components from the AL yields a Maximum Allowable Value (MAV) of 17.935 % of P span. The Actual Nominal Trip Setpoint of 8.30 % of P span (from 0 % to 20 % power) is conservative with respect to the Maximum Trip Setpoint (MTS). The current Allowable Value of < 9.09 % of P span (e.g., equivalent to 40 % of full steam flow at RTP) is conservative with respect to the MAV. The Allowable Value of < 9.09 % of P span is based on maintaining a Nominal Trip Setpoint value of 8.30 % of P span. The statistical combination of the COT and NON COT error components from CSA Calculation EE-0457 (Ref. 5.38) are given below.
CSAstm flow NON COTerror = [EA2 + PMA2 + PEA2 + (SCA+SMTE)2 + SD2 + SPSE2 + STE2 + SPE2 +
M1MTE2 + M2MTE2 + RTE2] 1/2 CSAstm flow NON COTerror = [0.02 + 1.0412 + 0.02 + (0.0+0.0)2 + 0.4902 + 0.02 + 1.6382 + 1.3312 + 0.02 +
0.2122 + 0.1742]1/2 CSAstm flow NON COTerror = + 2.419 % of P span (The PMA and RTE terms were converted from %
Flow to % P for 20 % power conditions. See Note 1 below)
CSAtfsp NON COTerror = [EA2 + PMA2 + PEA2 + (SCA+SMTE)2 + SD2 + SPSE2 + STE2 + SPE2 +
M1MTE2 + M2MTE2 +M5MTE2] 1/2 CSAtfsp NON COTerror = [0.02 + 0.02 + 0.02 + (0.5+0.219)2 + 0.3212 + 0.02 + 1.1912 + 0.02 + 0.02 +
0.2122 + 0.2122 ] 1/2 CSAtfsp NON COTerror = + 1.459 % of P span TOTAL NON COTerror = + (2.4192 + 1.4592)1/2 = + 2.825 % of P span CSA6 & 7COTerror = + (M12 + M22 + M12 + M22 + M52 + RD2)1/2 CSA6&7COTerror = + (0.02 + 0.52 + 0.02 + 0.52 + 0.3472) 1/2 CSA6&7COTerror = + 0.788 % of P span (the RD term was converted from % Flow to % P for 20 %
power conditions. See Note 1 below)
TLU = (TOTAL NON COTerror2 + CSA6&7COTerror2) 1/2 = (2.8252 + 0.7882) 1/2 = 2.933 % P span
EE-0116 Page 130 of 205 Revision 7 SURRY'S HI STEAM FLOW IN TWO STEAM LINES ESFAS INITIATION Analytical Limit (AL) 20.76 % dP span (Note 1)
TOTAL LOOP NON-COT ERRORS 2.825 % dP span 2.933% dP span Maximum Allowable Value (MAV)
UNCERTAINTY (TLU) 0.108 % dP span 17.935 % dP span COT ERRORS Maximum Trip Setpoint (MTS) 17.827 % dP span Actual Allowable Value (AV) 9.09 % dP span SAFETY MARGIN COT ERRORS 9.527 % dP span 0.788 % dP span Actual Trip Setpoint (ATS) 8.30 % dP span OPERATING MARGIN High Operating Limit 5.7 % dP span 2.60 % dP span (Based on SF/FF Mismatch Rx Trip)
Nominal Operating Limit 2.9 % dP span (20 % of Flownom)
Figure 4.4.6 Note 1: Calculation EE-0457 specifies a 3.0 % of flow span PMA value, a 0.5 % of flow span RTE value, and a 0.5 % of flow span RD value. Equation 2.3 from EE-0457 is used to convert from % of Flow span to % of P span. Equation 2.3 modified for a generic conversion from % of Flow span to % P of span is % P span = [% Flow span / 0.5] / [Flowmax /
Flow x]. Flowmax is the maximum indicated flowrate (i.e., 4.4
- 106 PPH) and Flow x is the flowrate of interest. At 20 %
power, Flow x = 20 % Flow, noting that the nominal flowrate at 100 % power is equal to 3.7533
- 106 PPH. To bound this analysis for the MUR uprate on both units at Surry, the nominal flow rate will be increased by 1.7 %, i.e., 3.7533
- 106 PPH
- 1.017 = 3.817
- 106 PPH. Flow x = 0.2
- 3.817
- 106 PPH = 0.7634
- 106 PPH.
% P span(PMA) = [3.0 / 0.5] / [4.4 / 0.7634] = 1.041 % P span
% P span(RTE) = [0.5 / 0.5] / [4.4 / 0.7634] = 0.174 % P span
% P span(RD) = [1.0 / 0.5] / [4.4 / 0.7634] = 0.347 % P span Note 2: Flowmax = 4.4 MPPH and Flownom = 3.7533 MPPH. Based on Technical Report EE-0100, Appendix 18-5 (Ref.
5.12), the equation used to convert from % Flownom to % P span is : % P span = ((% Flownom / Flowmax)2 / 1.26169))
- 100. See the example below for the conversion of the Analytical Limit of 60 % of Flownom to % P span for Pre and Post MUR conditions:
Pre-MUR ((0.6
- 3.7533) / 4.4)2 / 1.26169))
- 100 = 20.76 % P span (Bounding Value)
Post-MUR ((0.6
- 3.817) / 4.4)2 / 1.26169))
- 100 = 21.47 % P span
EE-0116 Page 131 of 205 Revision 7 4.4.7 Low TAVG Allowable Value : > 541.0 oF (Refs. 5.1, 5.7, 5.31 & 5.69)
Adding the Total Loop Uncertainty (TLU) to the Analytical Limit (AL) yields a Minimum Trip Setpoint (MTS) of 541.1 oF. Adding the NON COT error components to the Analytical Limit yields a Minimum Allowable Value (MAV) of 540.276 oF. The Actual Nominal Trip Setpoint of 543.0 oF is conservative with respect to the Minimum Trip Setpoint and the Actual Allowable Value of > 541.0 oF is conservative with respect to the Minimum Allowable Value. This Allowable Value of > 541.0 oF is based on maintaining a Nominal Trip Setpoint value of 543.0 oF. The actual Allowable Value of >
541.0 oF is slightly less than the calculated Allowable Value of > 541.342 oF. The 0.342 oF offset is accommodated in the Safety Margin of 1.898 oF. See Figure 4.4.7 for specific details.
The statistical combination of the COT and NON COT error components from CSA Calculation EE-0415 (Ref. 5.31) are given below. The COT and NON COT error components are used in Figure 4.4.7 to determine the Minimum Trip Setpoint (MTS) and the Minimum Allowable Value (MAV).
CSA11NON COTerror = [PMATAVG2 + (SCARTD+SMTERTD)2 + (SCARTD+SMTERTD)2 +
(SCARTD+SMTERTD)2 + (SCARTD+SMTERTD)2 + (4
- SDRTD2)+ M1MTE2 + M2MTE2 + M3MTE2 +
M4MTE2 + M5MTE2 + M7MTE2 + M11MTE2 + RTE2]1/2 CSA13NON COTerror = [1.702 + (0.417+0.167)2 + (0.417+0.167)2 + (0.417+0.167)2 + (0.417+0.167)2 +
(4
- 0.252) + 0.2482 + 0.2482 + 0.2482 + 0.2442 + 0.32 + 0.2602 + 0.1502 + 0.52] 1/2 CSA13NON COTerror = + 2.276 % of span = + 2.276 oF CSA13COTerror = + (M12 + M22 + M32 + M42 + M52 + M72 + M112 + RD2) 1/2 CSA13COTerror = + (0.52 + 0.52 + 0.52 + 0.52 + 0.52 + 0.52 + 0.52 + 1.02) 1/2 CSA13COTerror = + 1.658 % of span = + 1.658 oF
EE-0116 Page 132 of 205 Revision 7 SURRY'S LOW T AVG ESFAS INITIATION Nominal Operating Limit 547 °F Low Operating Limit 545°F OPERATING MARGIN 2.0 °F Actual Trip Setpoint (ATS) 543 °F COT ERRORS SAFETY MARGIN 2.0 °F 1.898 °F Minimum Trip Setpoint (MTS) 541.102 °F Actual Allowable Value (AV) 541 °F COT ERRORS 0.826 °F TOTAL LOOP 3.102 °F Minimum Allowable Value (MAV) 540.276 °F NON-COT ERRORS UNCERTAINTY (TLU) 2.276 °F Analytical Limit (AL) 538 °F Figure 4.4.7 4.4.8 Steam Line Pressure - Low Allowable Value : > 510.0 PSIG (Refs. 5.1, 5.7, 5.36 & 5.65)
Adding the Total Loop Uncertainty (TLU) to the Analytical Limit (AL) yields a Minimum Trip Setpoint (MTS) of 456.11 PSIG. Adding the NON COT error components to the Analytical Limit yields a Minimum Allowable Value (MAV) of 450.09 PSIG. The Actual Nominal Trip Setpoint of 525 PSIG is conservative with respect to the Minimum Trip Setpoint and the Actual Allowable Value of > 500 PSIG is conservative with respect to the Minimum Allowable Value. The current Allowable Value of > 500 PSIG will be changed to > 510 PSIG to conform to the requirements of Methods 1 and 2 as described in Sections 3.3.1 and 3.3.2. The revised Allowable Value of > 510 PSIG is conservative with respect to the calculated value using the CSA rack error terms from Calculation EE-0355 (Ref.5.36). The calculated Allowable Value for this function is 507.85 PSIG.
EE-0116 Page 133 of 205 Revision 7 The statistical combination of the COT and NON COT error components from CSA Calculation EE-0355 (Ref. 5.36) are given below. The COT and NON COT error components are used in Figure 4.4.8 to determine the Minimum Trip Setpoint (MTS) and the Minimum Allowable Value (MAV).
NON COTerror = + [EA2 + PMA2 + PEA2 + (SCA+SMTE)2 + SD2 + SPE2 + STE2 + SPSE2 + M10MTE2
+ M11MTE2 + M12MTE2 + RTE2]1/2 NON COTerror = + [0.02 + 0.02 + 0.02 + (0.5+0.207)2 + 0.4292 + 0.02 + 1.4752 + 0.02 + 0.02 + 0.1582 +
0.052 + 0.52 ]1/2 NON COTerror = + 1.771 % of span = + 24.79 PSIG COTerror = + (M102 +M112 + +M122 + RD2) 1/2 COTerror = + (0.02 + 0.52 + 0.52 + 1.02) 1/2 COTerror = + 1.225 % of span = + 17.15 PSIG SURRY'S STEAM LINE PRESSURE LOW ESFAS INITIATION Nominal Operating Limit 800 PSIG Low Operating Limit 755 PSIG OPERATING MARGIN 230 PSIG (Static)
Actual Trip Setpoint (ATS) 525 PSIG COT ERRORS 15.0 PSIG SAFETY MARGIN 68.89 PSIG (Static)
Actual Allowable Value (AV) 510 PSIG Minimum Trip Setpoint (MTS) 456.11 PSIG COT ERRORS 6.02 PSIG TOTAL LOOP 30.81PSIG Minimum Allowable Value (MAV) 450.09 PSIG UNCERTAINTY (TLU)
NON-COT ERRORS 24.79 PSIG Analytical Limit (AL) 425.3 PSIG Figure 4.4.8
EE-0116 Page 134 of 205 Revision 7 4.4.9 Steam Generator Water Level Low Low Reactor Trip/SI See item 4.3.13.
4.4.10 Low Intake Canal Level Allowable Value : 23 feet-5.85 inches (Refs. 5.1, 5.7, 5.42, 5.78, 5.79 & 5.80)
Adding the Total Loop Uncertainty (TLU) to the Analytical Limit (AL) yields a Minimum Trip Setpoint (MTS) of 23 feet-5.66 inches. Adding the NON COT error components to the Analytical Limit yields a Minimum Allowable Value (MAV) of 23 feet-5.63 inches. The Actual Nominal Trip Setpoint of 23 feet-6 inches conservative with respect to the Minimum Trip Setpoint and the Actual Allowable Value of 23 feet-6 inches is conservative with respect to the Minimum Allowable Value. However, the current Allowable Value is set equal to the Nominal Trip Setpoint. In this case, the Allowable Value will be changed from 23 feet-6 inches to 23 feet-5.85 inches. This revised Allowable Value will allow a 0.15 inch margin to be used for the COT error components. The revised Allowable Value of 23 feet-5.85 inches is conservative with respect to the calculated value using the CSA rack error terms from Calculation EE-0724 (Ref. 5.42) and Engineering Transmittal CEE 98-005 (Ref. 5.78).
The statistical combination of the COT and NON COT error components from CSA Calculation EE-0724 (Ref. 5.42) and Engineering Transmittal CEE 98-005 (Ref. 5.78) are given below. The COT and NON COT error components are used in Figure 4.4.10 to determine the Minimum Trip Setpoint (MTS) and the Minimum Allowable Value (MAV).
NON COTerror = SE + [EA2 + PMA2 + PEA2 + (SCA+SMTE)2 + SD2 + SPE2 + RCA2 + RTE2] 1/2 NON COTerror = 56.43 + [0.02 + 0.02 + 0.02 + (5.53 + 0.25)2 + 0.02 + 0.02 + 0.02 + 0.322] 1/2 NON COTerror = 56.43 + 5.789 seconds = 50.641 seconds to 62.22 seconds Converting seconds to inches : Calculation ME-0318 (Ref. 5.79) and Engineering Transmittal CEE 98-005 (Ref. 5.78) indicates that with a loss of power, the drop in canal level is linear with respect to time.
In 66 seconds, canal level will drop 5.972 inches. Thus, 5.972 inches/66 seconds = 0.0904848 inches/second. The Allowable Value of 23 feet- 5.85 inches calculates out to a voltage of 230 mV @
61.568 seconds using the range of 250 mV and 75.33 seconds from EE-0724.
NON COTerror = 50.641 seconds
- 0.0904848 inches = 4.58 inches to 62.22 seconds
- 0.0904848 inches
= 5.63 inches (worst case).
COTerror = (RMTE2 + RD2) 1/2 COTerror = (1.702 + 0.642) 1/2 = 1.816 seconds COTerror = + 1.816 seconds
- 0.0904848 inches = 0.1643 inches Figure 4.4.10 for specific details.
EE-0116 Page 135 of 205 Revision 7 SURRY'S LOW INTAKE CANAL LEVEL ESFAS INITIATION Nominal Operating Limit Variable (> 24 feet)
Low Operating Limit 24 feet OPERATING MARGIN 6 inches Actual Trip Setpoint (ATS) 23 feet-6 inches COT ERRORS 0.15 inches SAFETY MARGIN 0.34 inches Actual Allowable Value (AV) 23 feet-5.85 inches Minimum Trip Setpoint (MTS) 23 feet-5.66 inches COT ERRORS 0.03 inches TOTAL LOOP 5.66 inches Minimum Allowable Value (MAV) 23 feet-5.63 inches UNCERTAINTY (TLU)
NON-COT ERRORS 5.63 inches Analytical Limit (AL) 23 feet Figure 4.4.10 4.4.11 SG Water Level - High High Allowable Value : < 76.0 % Narrow Range (NR) Level (Refs. 5.1, 5.7, 5.35 & 5.60)
Subtracting the Total Loop Uncertainty (TLU) from the Analytical Limit (AL) yields a Maximum Trip Setpoint (MTS) of 85.46 % NR Level. Subtracting the NON COT error components from the Analytical Limit yields a Maximum Allowable Value (MAV) of 85.80 % NR Level. The Actual Nominal Trip Setpoint of 75.0 % NR Level is conservative with respect to the Maximum Trip Setpoint and the Actual Allowable Value of < 80.0 % NR Level is conservative with respect to the Maximum Allowable Value.
The Allowable Value of < 80.0 % NR Level will be changed to < 76.0 % NR Level to conform to the requirements of Methods 1 and 2 as described in Sections 3.3.1 and 3.3.2. The revised allowable value of < 76.0 % NR Level is conservative with respect to the calculated value using CSA rack error terms from Calculation EE-0432 (Ref. 5.35). The statistical combination of the COT and NON COT error
EE-0116 Page 136 of 205 Revision 7 components from CSA Calculation EE-0432 (Ref. 5.35) are given below. The COT and NON COT error components are used in Figure 4.4.11 to determine the Maximum Trip Setpoint (MTS) and the Maximum Allowable Value (MAV).
NON COTerror = SE + PMA2 + [PEA2 + (SCA+SMTE)2 + SD2 + SPE2 + STE2 + M1MTE2 + M3MTE2 +
RTE2] 1/2 NON COTerror = 0.0 + (-8.70) + [0.02 + (0.5+0.361)2 + 0.2812 + 1.1582 + 1.0872 + 0.02 + 0.1502 +
0.52]1/2 NON COTerror = - 10.601 % of span = - 10.601 % NR Level COTerror = + (M12 + M32 + RD2) 1/2 COTerror = + (0.02 + 0.52 + 1.02) 1/2 COTerror = + 1.118 % of span = + 1.118 % NR Level SURRY'S STEAM GENERATOR HI-2 LEVEL ESFAS INITIATION Analytical Limit (AL) 96.4 % NR Level TOTAL LOOP NON-COT ERRORS 10.601 % NR Level 10.939 % NR Level UNCERTAINTY (TLU)
Maximum Allowable Value (MAV) 85.799 % NR Level COT ERRORS 0.338 % NR Level Maximum Trip Setpoint (MTS) 85.461 % NR Level Actual Allowable Value (AV) 76.00 % NR Level COT ERRORS 1.00 % NR Level SAFETY MARGIN 10.461 % NR Level Actual Trip Setpoint (ATS) 75.00 % NR Level OPERATING MARGIN 26.0 % NR Level High Operating Limit 49.0 % NR Level Nominal Operating Limit 44.0 % NR Level Figure 4.4.11
EE-0116 Page 137 of 205 Revision 7 4.4.12 Refueling Water Storage Tank Level Low - Low RMT Initiation Allowable Values : > 12.7 % Wide Range (WR) Level and < 14.3 % Wide Range (WR) Level (Refs. 5.1, 5.7, 5.41 & 5.58)
There are two Analytical Limits and thus two Allowable Values associated with this function. The Analytical Limits are > 11.00 % WR Level and < 16.00 % WR Level. The corresponding Allowable Values are > 11.25 % WR Level and < 15.75 % WR Level. Both Allowable Values will be analyzed below.
Analysis for > 11.25 % Wide Range (WR) Level Adding the Total Loop Uncertainty (TLU) to the Analytical Limit (AL) yields a Minimum Trip Setpoint (MTS) of 12.799 % WR Level. Adding the NON COT error components to the Analytical Limit yields a Minimum Allowable Value (MAV) of 12.355 % WR Level. The Actual Nominal Trip Setpoint of 13.5 % WR Level is conservative with respect to the Minimum Trip Setpoint. The Actual Allowable Value of > 11.25 % WR Level is non-conservative with respect to the Minimum Allowable Value. The Allowable Value of > 11.25 % WR Level will be changed to > 12.7 % WR Level to conform to the requirements of Methods 1 and 2 as described in Sections 3.3.1 and 3.3.2. The revised Allowable Value of > 12.7 % WR Level is conservative with respect to the calculated value using CSA rack error terms from Calculation EE-0112 (Ref. 5.41).
The statistical combination of the COT and NON COT error components from CSA Calculation EE-0112 (Ref. 5.41) are given below. The COT and NON COT error components are used in Figure 4.4.12 to determine the Minimum Trip Setpoint (MTS) and the Minimum Allowable Value (MAV).
NON COTerror = SE + [EA2 + PMA2 + PEA2 + (SCA+SMTE)2 + SD2 + SPE2 + STE2 + SPSE2 +
M1MTE2 + M3MTE2 + RTE2]1/2 NON COTerror = 0.0 + [0.02 + 0.02 + 0.02 + (0.5+0.234)2 + 0.2702 + 0.02 + 0.9762 + 0.02 + 0.02 + 0.1502
+ 0.52]1/2 NON COTerror = + 1.355 % of span COTerror = + (M12 +M32 + RD2) 1/2 COTerror = + (0.02 +0.52 + 1.02) 1/2 COTerror = + 1.118 % of span
EE-0116 Page 138 of 205 Revision 7 Analysis for < 15.75 % Wide Range (WR) Level Subtracting the Total Loop Uncertainty (TLU) from the Analytical Limit (AL) yields a Maximum Trip Setpoint (MTS) of 14.201 % WR Level. Subtracting the NON COT error components from the Analytical Limit yields a Maximum Allowable Value (MAV) of 14.645 % WR Level. The Actual Nominal Trip Setpoint of 13.5 % WR Level is conservative with respect to the Maximum Trip Setpoint.
The Actual Allowable Value of < 15.75 % WR Level is non-conservative with respect to the Maximum Allowable Value. The Allowable Value of < 15.75 % WR Level will be changed to < 14.3 % WR Level to conform to the requirements of Methods 1 and 2 as described in Sections 3.3.1 and 3.3.2. The revised Allowable Value of < 14.3 % WR Level is conservative with respect to the calculated value using CSA rack error terms from Calculation EE-0112 (Ref. 5.41).
The statistical combination of the COT and NON COT error components from CSA Calculation EE-0112 (Ref. 5.41) are given below. The COT and NON COT error components are used in Figure 4.4.12 to determine the Maximum Trip Setpoint (MTS) and the Maximum Allowable Value (MAV).
NON COTerror = SE + [EA2 + PMA2 + PEA2 + (SCA+SMTE)2 + SD2 + SPE2 + STE2 + SPSE2 +
M1MTE2 + M3MTE2 + RTE2]1/2 NON COTerror = 0.0 + [0.02 + 0.02 + 0.02 + (0.5+0.234)2 + 0.2702 + 0.02 + 0.9762 + 0.02 + 0.02 + 0.1502
+ 0.52]1/2 NON COTerror = + 1.355 % of span COTerror = + (M12 +M32 + RD2) 1/2 COTerror = + (0.02 +0.52 + 1.02) 1/2 COTerror = + 1.118 % of span See Figure 4.4.12 for specific details.
EE-0116 Page 139 of 205 Revision 7 SURRY'S RWST LEVEL LOW- LOW RMT ESFAS INITIATION Nominal Operating Limit 97.6 % WR Level Low Operating Limit 96.7 % WR Level High Analytical Limit (AL) 16.00 % WR Level TOTAL LOOP NON-COT 1.799 % WR Level ERRORS 1.355 %
UNCERTAINTY (TLU)
Maximum Allowable Value (MAV)
OPERATING 14.645 % WR Level MARGIN Actual Allowable Value (AV) 83.2 % WR Level COT 14.300 % WR Level ERRORS 0.444 %
Maximum Trip Setpoint (MTS) 14.201 % WR Level COT SAFETY MARGIN ERRORS 0.701% WR Level 0.80 % WR Level Actual Trip Setpoint (ATS) 13.5 % WR Level SAFETY MARGIN 0.701 % WR Level COT ERRORS 0.80 % WR Level Minimum Trip Setpoint (MTS)
COT 12.799 % WR Level ERRORS 0.444 %
TOTAL LOOP Actual Allowable Value (AV) 1.799 % WR Level 12.700 % WR Level Minimum Allowable Value (MAV) 12.355 % WR Level UNCERTAINTY (TLU)
NON-COT ERRORS 1.355 %
Low Analytical Limit (AL) 11.00 % WR Level Figure 4.4.12
EE-0116 Page 140 of 205 Revision 7 4.4.13 Refueling Water Storage Tank Level - Low Inside/Outside Recirculation Spray Pump Interlock Allowable Values : > 59.0 % Wide Range (WR) Level and < 61.0 % Wide Range (WR) Level (Refs. 5.1, 5.7, 5.41, 5.58 & 5.83)
There are two Analytical Limits and thus two Setting Limits associated with this new function. The Analytical Limits are based on input from the Nuclear Analysis and Fuel group and Technical Report NE-1460 (Reference 5.83). The Analytical Limits are > 57.50 % WR Level and < 62.50 % WR Level. The corresponding Setting Limits to be used in Technical Specifications are > 59.00 % WR Level and < 61.00 % WR Level. Both Setting Limits will be analyzed below.
Analysis for > 59.00 % Wide Range (WR) Level Adding the Total Loop Uncertainty (TLU) to the Analytical Limit (AL) yields a Minimum Trip Setpoint (MTS) of 59.299 % WR Level. Adding the NON COT error components to the Analytical Limit yields a Minimum Allowable Value (MAV) of 58.855 % WR Level. The Actual Nominal Trip Setpoint of 60.00 % WR Level is conservative with respect to the Minimum Trip Setpoint. The Actual Allowable Value of > 59.00 % WR Level is conservative with respect to the Minimum Allowable Value. This Allowable Value of > 59.00 % WR Level is based on maintaining a Nominal Trip Setpoint value of 60.00 % WR Level. The Allowable Value of > 59.00
% WR Level is conservative with respect to the calculated value using rack error terms (i.e., COT error terms) from Dominion Channel Statistical Allowance (CSA) Calculation EE-0112 (Reference 5.41).
Analysis for < 61.00 % Wide Range (WR) Level Subtracting the Total Loop Uncertainty (TLU) from the Analytical Limit (AL) yields a Maximum Trip Setpoint (MTS) of 60.701 % WR Level. Subtracting the NON COT error components from the Analytical Limit yields a Maximum Allowable Value (MAV) of 61.145 % WR Level. The Actual Nominal Trip Setpoint of 60.00 %
WR Level is conservative with respect to the Maximum Trip Setpoint. The Actual Allowable Value of < 61.00
% WR Level is conservative with respect to the Maximum Allowable Value. This Allowable Value of < 61.00
% WR Level is based on maintaining a Nominal Trip Setpoint value of 60.00 % WR Level. The Allowable Value of < 61.00 % WR Level is conservative with respect to the calculated value using rack error terms (i.e.,
COT error terms) from Dominion Channel Statistical Allowance (CSA) Calculation EE-0112 (Reference 5.41).
The statistical combination of the COT and NON COT error components from CSA Calculation EE-0112 are given below. The COT and NON COT error components are used in Figure 4.4.13 to determine the Minimum/Maximum Trip Setpoints (MTS) and the Minimum/Maximum Allowable Values (MAV).
NON COTerror = SE + [EA2 + PMA2 + PEA2 + (SCA+SMTE)2 + SD2 + SPE2 + STE2 + SPSE2 + M1MTE2 +
M3MTE2 + RTE2]1/2 NON COTerror = 0.0 + [0.02 + 0.02 + 0.02 + (0.5+0.234)2 + 0.2702 + 0.02 + 0.9722 + 0.02 + 0.02 + 0.1502 +
0.52]1/2 NON COTerror = + 1.355 % of span COTerror = + (M12 +M32 + RD2) 1/2
EE-0116 Page 141 of 205 Revision 7 COTerror = + (0.02 +0.52 + 1.02) 1/2 COTerror = + 1.118 % of span See Figure 4.4.13 for specific details.
SURRY'S RWST LEVEL LO ESFAS INITIATION Nominal Operating Limit 97.6 % WR Level Low Operating Limit 96.7 % WR Level High Analytical Limit (AL) 62.50 % WR Level TOTAL LOOP NON-COT 1.799 % WR Level ERRORS 1.355 %
Maximum Allowable Value (MAV)
UNCERTAINTY (TLU)
OPERATING 61.145 % WR Level MARGIN COT Actual Allowable Value (AV) 0.444 %
36.70 % WR Level 61.00 % WR Level ERRORS Maximum Trip Setpoint (MTS) 60.701 % WR Level COT COT SAFETY MARGIN 0.701% WR Level ERRORS ERRORS Actual Trip Setpoint (ATS) 60.0 % WR Level SAFETY MARGIN 1.0 % WR Level 1.0 % WR Level 0.701 % WR Level Minimum Trip Setpoint (MTS) 59.299 % WR Level COT TOTAL LOOP ERRORS 1.799 % WR Level 0.444 % Actual Allowable Value 59.0 % WR Level Minimum Allowable Value UNCERTAINTY (TLU) 58.855 % WR Level NON-COT 1.355 %
ERRORS Low Analytical Limit (AL) 57.50 % WR Level Figure 4.4.13 Note: The COT errors are based on the Minimum Trip Setpoint value minus the Minimum Allowable value and the Actual Trip Setpoint value minus the Actual Allowable Value.
EE-0116 Page 142 of 205 Revision 7 ESFAS Permissives Note: In the context of this document, the terms Allowable Value and Setting Limit and Limiting Safety System Setting (LSSS) have the same meaning and intent.
4.4.14 Pressurizer Pressure, P-11 Allowable Value : < 2010 PSIG (Refs. 5.1, 5.7, 5.32 & 5.44)
Only one Allowable Value will be provided for the P-11 function. The automatic disabling of the manual block of safety injection on increasing pressure is the portion of this function that is important to safety. The revised Allowable Value of < 2010 PSIG is based on maintaining a Nominal Trip Setpoint value of 2000 PSIG. In this case, the current Allowable Value of < 2000 PSIG is set equal to the Nominal Trip Setpoint. Changing the Allowable Value to < 2010 PSIG will take into account the tolerances associated with the CSA rack error terms from Calculation EE-0514 (Ref 5.32). The calculated Allowable Value for this function is < 2008.9 PSIG. Note that this function is assumed to be available in the Safety Analysis but no specific setpoint is assumed. The proposed Allowable Value for Surry is the same as the Allowable Value in North Annas Improved Technical Specifications for the automatic disabling of the manual block of safety injection.
4.4.15 TAVG, P-12 Allowable Value : < 545.0 oF (Refs. 5.1, 5.7, 5.31, 5.69)
Only one Allowable Value will be provided for the P-12 function. The automatic disabling of the manual block of the High Steam Flow in 2/3 Lines or Low Steam Pressure coincident with Low TAVG on increasing temperature is the portion of this function that is important to safety. The revised Allowable Value of < 545.0 oF is based on maintaining a Nominal Trip Setpoint value of < 544.0 oF. In this case, the current Allowable Value of < 543.0 oF is set equal to the Nominal Trip Setpoint of the Low TAVG Interlock (see section 4.4.7). Changing the Allowable Value to < 545.0 oF will take into account the tolerances associated with the CSA rack error terms from Calculation EE-0415 (Ref 5.31). The revised Allowable Value for this function is conservative with respect to the calculated value of < 545.658 oF (See COTerror from item 4.4.7). Note that this function is assumed to be available in the Safety Analysis but no specific setpoint is assumed.
EE-0116 Page 143 of 205 Revision 7 4.5 Limiting Trip Setpoints, Allowable Values, As Found Tolerances, and As Left Tolerances for Kewaunee Reactor Protection System (RPS) Instrumentation to Support the Setpoint Control Program Note : Only the limiting As Found Tolerance value will be addressed in analysis for each Reactor Trip Function described below.
Reactor Trips 4.5.1 Power Range Neutron Flux High Setpoint Reactor Trip As Found Tolerance Value : 105 % RTP + 1.5 % RTP (Refs. 5.1, 5.90, 5.91, 5.103, and 5.104)
Subtracting the Total Loop Uncertainty (TLU) from the Analytical Limit (AL) yields a Limiting Trip Setpoint (LTSP) of 110.96 % Rated Thermal Power (RTP). Subtracting the NON COT error components from the Analytical Limit yields an Allowable Value (AV) of 111.19 % RTP. The Nominal Trip Setpoint (NTSP) of 105.0 % RTP is conservative with respect to the Limiting Trip Setpoint and the As Found Tolerance Value of < 106.5 % RTP is conservative with respect to the Allowable Value. The current Custom Technical Specification (CTS) LSSS value of < 109 % RTP will be changed to an As Found Tolerance value < 106.5 % RTP to conform to the requirements of TSTF-493, Rev. 4 and RIS 2006-17. The As Found Tolerance is based on a Nominal Trip Setpoint value of 105 % RTP. The Nominal Trip Setpoint value of 105 % RTP will allow a 1.5 % RTP margin to be used for the COT error components. The revised As Found Tolerance value of < 106.5 % RTP is conservative with respect to the calculated value of < 106.56 % RTP using the CSA rack error terms from Calculation C11705 (Ref 5.91).
The calculated As Found Tolerance value for this function is < 106.562 % RTP. The 0.062 % RTP offset will be subtracted from the calculated value to arrive at a value that can be determined on the indicator. The statistical combination of the COT and NON COT error components from CSA Calculation C11705 (Ref. 5.91) are given below. The COT and NON COT error components are used in Figure 4.5.1 to determine the Limiting Trip Setpoint (LTSP) and the Allowable Value (AV).
NON COTerror = SE + (PMA12 + PMA32 + M1MTE2 + M3MTE + RTE2) 1/2 NON COTerror = 0.333 + (1.4172 + 5.1242 + 0.1852 + 0.1932 + 0.52) 1/2 NON COTerror = + 5.679 % of span = + 6.815 % RTP COTerror = + (M12 + M32 + RD2) 1/2 COTerror = + (0.052 + 0.8332 +1.02) 1/2 COTerror = + 1.302 % of span = + 1.562 % RTP (for conservatism round to + 1.5 % RTP)
As Found Tolerance (AFT) = 105 % RTP + 1.5 % RTP As Left Tolerance (ALT) = 105 % RTP + 1.0 % RTP(1)
EE-0116 Page 144 of 205 Revision 7 See Figure 4.5.1 for specific details.
(1) As Left Tolerance = + (M12 + M32) 1/2 = + (0.052 + 0.8332)1/2 = + 0.834 % of span = + 1.001 % RTP KEWAUNEE'S POWER RANGE NEUTRON FLUX HIGH REACTOR TRIP Analytical Limit (AL) 118.00 % RTP NON-COT ERRORS 6.815 % RTP TOTAL LOOP 7.040 % RTP Allowable Value (AV)
UNCERTAINTY (TLU) 111.185 % RTP COT ERRORS 0.225 % RTP Limiting Trip Setpoint (LTSP) 110.960 % RTP As Found Tolerance (AFT)
COT ERRORS SAFETY MARGIN 106.50 % RTP 1.50 % RTP 5.960 % RTP Nominal Trip Setpoint (NTSP) 105.00 % RTP OPERATING MARGIN 3.00 % RTP High Operating Limit 102.00 % RTP Nominal Operating Setpoint 100.00 % RTP Figure 4.5.1
EE-0116 Page 145 of 205 Revision 7 4.5.2 Power Range Neutron Flux Low Setpoint Reactor Trip As Found Tolerance: 24.5 % RTP + 1.5 % RTP (Refs. 5.1, 5.90, 5.91, 5.103, and 5.104)
Subtracting the Total Loop Uncertainty (TLU) from the Analytical Limit (AL) yields a Limiting Trip Setpoint (LTSP) of 27.96 % Rated Thermal Power (RTP). Subtracting the NON COT error components from the Analytical Limit yields an Allowable Value (AV) of 28.19 % RTP. The Nominal Trip Setpoint (NTSP) of 24.5 % RTP is conservative with respect to the Limiting Trip Setpoint and the As Found Tolerance Value of < 26.062 % RTP (conservatively round to < 26.0) is conservative with respect to the Allowable Value. The current Custom Technical Specification (CTS) LSSS value of < 25 % RTP will be changed to an As Found Tolerance value of < 26 % RTP to conform to the requirements of TSTF-493, Rev. 4 and RIS 2006-17. The As Found Tolerance is based on a Nominal Trip Setpoint value of 24.5 % RTP. The Nominal Trip Setpoint value of 24.5 % RTP will allow a 1.5 % RTP margin to be used for the COT error components.
The statistical combination of the COT and NON COT error components from CSA Calculation C11705 (Ref. 5.91) are given below. The COT and NON COT error components are used in Figure 4.5.2 to determine the Limiting Trip Setpoint (LTSP) and the Allowable Value (AV).
NON COTerror = SE + (PMA12 + PMA32 + M1MTE2 + M4MTE + RTE2) 1/2 NON COTerror = 0.333 + (1.4172 + 5.1242 + 0.1852 + 0.1932 + 0.52) 1/2 NON COTerror = + 5.679 % of span = + 6.815 % RTP COTerror = + (M12 + M42 + RD2) 1/2 COTerror = + (0.052 + 0.8332 +1.02) 1/2 COTerror = + 1.302 % of span = + 1.562 % RTP (for conservatism round to + 1.5 % RTP)
As Found Tolerance (AFT) = 24.5 % RTP + 1.5 % RTP As Left Tolerance (ALT) = 24.5% RTP + 1.0 % RTP(1)
See Figure 4.5.2 for specific details.
(2) As Left Tolerance = + (M12 + M42)1/2 = + (0.052 + 0.8332)1/2 = + 0.834 % of span = + 1.001 % RTP
EE-0116 Page 146 of 205 Revision 7 KEWAUNEE'S POWER RANGE NEUTRON FLUX LOW SETPOINT REACTOR TRIP AnalyticalLimit (AL) 35.0 % RTP NON-COT ERRORS 6.815 % RTP TOTAL LOOP 7.040 % RTP UNCERTAINTY (TLU)
Allowable Value (AV) 28.19 % RTP COT ERRORS 0.225 % RTP Limiting Trip Setpoint (LTSP) 27.960 % RTP As Found Tolerance (AFT)
SAFETY MARGIN 26.00 % RTP COT ERRORS 1.5% RTP 3.46 % RTP Nominal Trip Setpoint (NTSP) 24.50 % RTP OPERATING MARGIN 13.5 % RTP High Operating Limit 11.0 % RTP Nominal Operating Setpoint 10.0 % RTP Figure 4.5.2
EE-0116 Page 147 of 205 Revision 7 4.5.3 Power Range Neutron Flux High Positive Rate Reactor Trip As Found Tolerance: 5.0 % RTP + 1.3 % RTP with a time constant of 2.3 seconds + 0.2 seconds (Refs. 5.1, 5.11, 5.12, 5.13, 5.73, 5.90, 5.91, 5.104, 5.136, & 5.142)
The current Kewaunee Custom Technical Specifications (CTS) LSSS value for this function is 15.0 % /
q / 5.0 seconds. The manner in which this specification is presented in Kewaunees CTS is different than the typical presentation in Standardized Technical Specifications (STS) or in Improved Technical Specifications (ITS). The typical expression for this function in STS or ITS would be < 15.0 % RTP with a time constant > 5.0 Seconds. For consistency and clarity, the expression for this function will be written in the ITS format. The current static Nominal Trip Setpoint (NTSP) for this function is (+) 5.0
% RTP and the Rate Lag Derivative Time Constant associated with this function is currently set at a nominal value of 2 seconds versus the required CTS LSSS value of 5.0 seconds.
For Rate Lag Derivative functions, conservative settings are > the desired/required time constant. The Power Range Neutron Flux Positive Rate Reactor Trip is developed based on a combination of the dynamic compensation from the Rate Lag Derivative Module (NM311) and the static trip setpoint installed in the Bistable Relay Driver (NC303). When Kewaunees current settings for Rate Lag Derivative Module (i.e., nominal 2 second time constant) and the Bistable Relay Driver (i.e., nominal trip setpoint is + 5.0 % RTP) are combined, the Power Range Neutron Flux Positive Rate Reactor Trip function is set conservative when compared to the current CTS LSSS settings (i.e., + 15.0 % RTP with a time constant of 5 seconds) for all postulated conditions which include both a ramp and a step. The major contributing factor that results in this determination is based on the fact that the nominal trip setpoint is set at 5.0 % RTP versus 15.0 % RTP. The currently installed settings versus the current LSSS settings will be compared below for both a step and a ramp.
Based on References 5.12, 5.13, 5.136, and 5.137, the equation to determine the output of a Rate Lag Derivative Module for a step input is:
VOUT = G * (e -t/t1 * (VF - VI) + B)
Where:
G = Module Gain = 1.0000 V/V e = antilog of the natural log (ex) t = time of interest (for this example use 0.1 second) t1 = Rate Lag Derivative Time Constant = 2 or 5 Seconds VF = Voltage input to the Rate Lag Derivative Module after the step change = 8.771 VDC VI = Voltage input to the Rate Lag Derivative Module before the step change = 8.333 VDC B = Rate Lag Derivative Module Bias = 0.000 VDC There is no pedestal voltage for the NIS Rate Lag Derivative Modules. For a step change starting at VOUT = 0.000 VDC with the currently installed settings, i.e., + 5.0 % RTP = (5 %/120 %)
- 10.000 VDC
= + 0.417 VDC and a nominal Rate Lag Derivative Time Constant of 2 seconds, the Power Range Neutron Flux Positive Rate Reactor Trip will occur with a power change of 5.256 % RTP. This includes
EE-0116 Page 148 of 205 Revision 7 a conservative assumption of 0.1 seconds used for the time of interest (i.e., t) to account for on-board module lag(s) and the process lags. Therefore, the common parameters are:
Bistable Relay Driver Setpoint = 5.0 % RTP = 0.417 VDC Rate Lag Derivative Time Constant = 2 seconds To make the Positive Rate Bistable Relay Driver trip, we must use a step change of 0.438 VDC to account for lags in the system as discussed above. This step change voltage is calculated as:
(1 / e -0.1/2)
- 0.417 VDC = 0.438 VDC With the currently installed settings, NM311 will output the following:
VOUT(NM311) = 1.0000 * ( e -0.1/2 * (8.771 - 8.333) + 0.000)
VOUT(NM311) = 0.417 VDC (Bistable Relay Driver TRIP), noting that actual power is equal to (0.438 VDC / 10.000 VDC)
Using the same input parameters and substituting Kewaunees current LSSS settings, NM311 will output the following:
VOUT(NM311) = 1.0000 * ( e -0.1/5 * (8.771 - 8.333) + 0.000)
VOUT(NM311) = 0.429 VDC (Bistable Relay Driver RESET), noting that actual power is equal to (+) 5.256
% RTP. However, the installed setpoint for the Bistable Relay Driver would be set at (+) 15.0 % RTP =
- 10.000 VDC = 1.250 VDC.
Based on References 5.12, 5.13, 5.136, and 5.137, the equation to determine the output of a Rate Lag Derivative Module for a ramp input is:
VOUT = G
- VI + t1
- G * (1 - e -t/t1) + B Where:
G = Module Gain = 1.0000 V/V e = antilog of the natural log (ex) t = time of interest (for this example use 5 seconds) t1 = Rate Lag Derivative Time Constant = 2 or 5 Seconds VI = Voltage input to the Rate Lag Derivative Module before the ramp starts = 8.333 VDC RR = Ramp Rate (VDC/Second)
B = Rate Lag Derivative Module Bias = 0.000 VDC The assumption used for this example for the Ramp Rate (RR) is a (+) 15.0 RTP power change in 5 seconds. That means the indicated power on the Full Power Meter goes from 100 % RTP to 115 % RTP in 5 seconds. So the Ramp Rate will be [(15 % RTP / 120 % RTP)
- 10.000 VDC] / 5 seconds = 0.250 VDC / second = 3.0 % RTP / second. The currently installed settings versus the current Technical Specifications LSSS settings will be compared below for a ramp of (+) 3.0 % RTP / second at a time of interest (t) of 5 seconds after the ramp begins.
EE-0116 Page 149 of 205 Revision 7 With the currently installed settings, the Positive Rate Trip will respond as shown below:
Nominal Trip Setpoint = (+) 5.0 % RTP = 0.417 VDC Nominal Rate Lag Derivative Time Constant = 2 Seconds VOUT(NM311) = 1.0000
- 0.000 + 2
- 0.250
- 1.0000 (1 - e -5/2) + 0.000 VOUT(NM311) = 0.459 VDC (Bistable Relay Driver TRIP)
With the current Technical Specifications LSSS settings, the Positive Rate Trip will respond as shown below:
Nominal Trip Setpoint = (+) 15.0 % RTP = 1.250 VDC Nominal Rate Lag Derivative Time Constant = 5 Seconds VOUT(NM311) = 1.0000
- 0.000 + 5
- 0.250
- 1.0000 (1 - e -5/5) + 0.000 VOUT(NM311) = 0.790 VDC (Bistable Relay Driver RESET)
As can be seen from the examples above, from a dynamic perspective, the current Technical Specifications LSSS setting for the Rate Lag Derivative Time Constant (i.e., time constant = 5 seconds) will yield the most conservative output from NM311 for both a ramp and a step. However, when the dynamics and the statics are combined for the overall function, noting that the installed static nominal trip setpoint is set conservative by 10.0 % RTP, the currently installed settings are conservative for all conditions. It should also be noted that Kewaunees currently installed settings of (+) 5.0 % RTP with a Rate Lag Derivative Time Constant of 2 seconds are consistent with the nominal Standardized Technical Specifications (STS) values for this function and are identical to North Annas settings for this function.
Note : This trip function is not credited in the USAR Chapter 14 Safety Analysis (Ref. 5.1). A CSA Calculation has not been performed for this function. CSA Calculation 11705 (Ref. 5.91) and Instrument Surveillance Procedure SP-48-004A (Ref. 5.104) were used to perform this analysis.
Static As Found Tolerance (AFT) = 5.0 % RTP + 1.3 % RTP(1)
Static As Left Tolerance (ALT) = 5.0% RTP + 0.5 % RTP(2)
Dynamic As Found Tolerance = 2.3 seconds + 0.2 seconds(3)
Dynamic As Left Tolerance = 2.3 seconds + 0.2 seconds(3)
(1) AFT = + (M12+NM3112+NC3032+RD2) 1/2 = + (0.052+0.052+0.4172+1.02) 1/2 = + 1.086 % span = + 1.303 % RTP (2) ALT = + (M12+NM3112+NC3032) 1/2 = + (0.052+0.052+0.4172) 1/2 = + 0.424 % span = + 0.508 % RTP (3) The Dynamic Tolerance is equal to + 10 % of the desired time constant based on Reference 5.73.
Note: the calibration accuracy of NC303 is + 0.5 % RTP = + (0.5 % / 120 %)
- 100 % span = + 0.417 % span
EE-0116 Page 150 of 205 Revision 7 4.5.4 Power Range Neutron Flux High Negative Rate Reactor Trip As Found Tolerance: 5.0 % RTP + 1.3 % RTP with a time constant of 2.3 seconds + 0.2 seconds (Refs. 5.1, 5.11, 5.12, 5.13, 5.73, 5.90, 5.91, 5.104, 5.136, & 5.142)
The current Kewaunee Custom Technical Specifications (CTS) LSSS value for this function is 10.0 % /
q / 5.0 seconds. The manner in which this specification is presented in Kewaunees CTS is different than the typical presentation in Standardized Technical Specifications (STS) or in Improved Technical Specifications (ITS). The typical expression for this function in STS or ITS would be < 10.0 % RTP with a time constant > 5.0 Seconds. For consistency and clarity, the expression for this function will be written in the ITS format. The current static Nominal Trip Setpoint (NTSP) for this function is (-) 5.0 %
RTP and the Rate Lag Derivative Time Constant associated with this function is currently set at a nominal value of 2 seconds versus the required CTS LSSS value of 5.0 seconds.
For Rate Lag Derivative functions, conservative settings are > the desired/required time constant. The Power Range Neutron Flux Negative Rate Reactor Trip is developed based on a combination of the dynamic compensation from the Rate Lag Derivative Module (NM311) and the static trip setpoint installed in the Bistable Relay Driver (NC301). When Kewaunees current settings for Rate Lag Derivative Module (i.e., nominal 2 second time constant) and the Bistable Relay Driver (i.e., nominal trip setpoint is + 5 % RTP) are combined, the Power Range Neutron Flux Negative Rate Reactor Trip function is set conservative when compared to the current CTS LSSS settings (i.e., - 10 % RTP with a time constant of 5 seconds) for all postulated conditions which include both a ramp and a step. The major contributing factor that results in this determination is based on the fact that the nominal trip setpoint is set at - 5.0 % RTP versus - 10.0 % RTP. The currently installed settings versus the current LSSS settings will be compared below for both a step and a ramp.
Based on References 5.12, 5.13, 5.136, and 5.137, the equation to determine the output of a Rate Lag Derivative Module for a step input is:
VOUT = G * (e -t/t1 * (VF - VI) + B)
Where:
G = Module Gain = 1.0000 V/V e = antilog of the natural log (ex) t = time of interest (for this example use 0.1 second) t1 = Rate Lag Derivative Time Constant = 2 or 5 Seconds VF = Voltage input to the Rate Lag Derivative Module after the step change = 7.895 VDC VI = Voltage input to the Rate Lag Derivative Module before the step change = 8.333 VDC B = Rate Lag Derivative Module Bias = 0.000 VDC There is no pedestal voltage for the NIS Rate Lag Derivative Modules. For a step change starting at VOUT = 0.000 VDC with the currently installed settings, i.e., - 5.0 % RTP = (- 5 %/120 %)
- 10.000 VDC = - 0.417 VDC and a nominal Rate Lag Derivative Time Constant of 2 seconds, the Power Range Neutron Flux Negative Rate Reactor Trip will occur with a power change of - 5.256 % RTP. This
EE-0116 Page 151 of 205 Revision 7 includes a conservative assumption of 0.1 seconds used for the time of interest (i.e., t) to account for on-board module lag(s) and the process lags. Therefore, the common parameters are:
Bistable Relay Driver Setpoint = - 5.0 % RTP = - 0.417 VDC Rate Lag Derivative Time Constant = 2 seconds To make the Negative Rate Bistable Relay Driver trip, we must use a step change of - 0.438 VDC to account for lags in the system as discussed above. This step change voltage is calculated as:
(1 / e -0.1/2) * - 0.417 VDC = - 0.438 VDC With the currently installed settings, NM311 will output the following:
VOUT(NM311) = 1.0000 * ( e -0.1/2 * (7.895 - 8.333) + 0.000)
VOUT(NM311) = - 0.417 VDC (Bistable Relay Driver TRIP), noting that actual power is equal to (-) 5.256
% RTP.
Using the same input parameters and substituting Kewaunees current LSSS settings, NM311 will output the following:
VOUT(NM311) = 1.0000 * ( e -0.1/5 * (7.895 - 8.333) + 0.000)
VOUT(NM311) = - 0.429 VDC (Bistable Relay Driver RESET), noting that actual power is equal to (-)
5.256 % RTP. However, the installed setpoint for the Bistable Relay Driver would be set at (-) 10 %
- 10.000 VDC = - 0.833 VDC.
Based on References 5.12, 5.13, 5.136, and 5.137, the equation to determine the output of a Rate Lag Derivative Module for a ramp input is:
VOUT = G
- VI + t1
- G * (1 - e -t/t1) + B Where:
G = Module Gain = 1.0000 V/V e = antilog of the natural log (ex) t = time of interest (for this example use 10 seconds) t1 = Rate Lag Derivative Time Constant = 2 or 5 Seconds VI = Voltage input to the Rate Lag Derivative Module before the ramp starts = 8.333 VDC RR = Ramp Rate (VDC/Second)
B = Rate Lag Derivative Module Bias = 0.000 VDC The currently installed settings versus the current Technical Specifications LSSS settings will be compared below for the minimum ramp of (-) 3.0 % RTP / second at a time of interest (t) of 5 seconds after the ramp begins. This is the minimum ramp rate and approximate ramp time required to achieve a trip for either condition. The Ramp Rate VDC/Second = ( - 3.0 % RTP/120 % RTP)
- 10 VDC = (-)
0.250 VDC / Second.
EE-0116 Page 152 of 205 Revision 7 With the currently installed settings, the Negative Rate Trip will respond as shown below:
Nominal Trip Setpoint = (-) 5.0 % RTP = - 0.417 VDC Nominal Rate Lag Derivative Time Constant = 2 Seconds VOUT(NM311) = 1.0000
- 0.000 + 2 * - 0.250
- 1.0000 (1 - e -5/2) + 0.000 VOUT(NM311) = - 0.459 VDC (Bistable Relay Driver TRIP)
With the current Technical Specifications LSSS settings, the Negative Rate Trip will respond as shown below:
Nominal Trip Setpoint = (-) 10.0 % RTP = - 0.833 VDC Nominal Rate Lag Derivative Time Constant = 5 Seconds VOUT(NM311) = 1.0000
- 0.000 + 5 * - 0.250
- 1.0000 (1 - e -5/5) + 0.000 VOUT(NM311) = - 0.790 VDC (Bistable Relay Driver RESET)
As can be seen from the examples above, from a dynamic perspective, the current Technical Specifications LSSS setting for the Rate Lag Derivative Time Constant (i.e., time constant = 5 seconds) yields the most conservative output from NM311 for both a ramp and a step. However, when the dynamics and the statics are combined for the overall function, noting that the installed static nominal trip setpoint is set conservative by 5.0 % RTP, the currently installed settings are conservative for all conditions. It should also be noted that Kewaunees currently installed settings of (-) 5.0 % RTP with a Rate Lag Derivative Time Constant of 2 seconds are consistent with the nominal Standardized Technical Specifications (STS) values for this function and are identical to North Annas settings for this function.
Finally, Kewaunees installed settings for this function are consistent with the requirements of WCAP-10298-A which specify nominal settings for the Power Range Negative Rate Trip of (-) 5.0 % RTP with a time constant of 2 seconds (Ref. 5.138).
Note : This trip function is not credited in the USAR Chapter 14 Safety Analysis (Ref. 5.1). A CSA Calculation has not been performed for this function. CSA Calculation 11705 (Ref. 5.91) and Instrument Surveillance Procedure SP-48-004A (Ref. 5.104) were used to perform this analysis.
Static As Found Tolerance (AFT) = 5.0 % RTP + 1.3 % RTP(1)
Static As Left Tolerance (ALT) = 5.0% RTP + 0.5 % RTP(2)
Dynamic As Found Tolerance = 2.3 seconds + 0.2 seconds(3)
Dynamic As Left Tolerance = 2.3 seconds + 0.2 seconds(3)
(1) AFT = + (M12+NM3112+NC3012+RD2) 1/2 = + (0.052+0.052+0.4172+1.02) 1/2 = + 1.086 % span = + 1.303 % RTP (2) ALT = + (M12+NM3112+NC3012) 1/2 = + (0.052+0.052+0.4172) 1/2 = + 0.424 % span = + 0.508 % RTP (3) The Dynamic Tolerance is equal to + 10 % of the desired time constant based on Reference 5.73.
Note: the calibration accuracy of NC301 is + 0.5 % RTP = + (0.5 % / 120 %)
- 100 % span = + 0.417 % span
EE-0116 Page 153 of 205 Revision 7 4.5.5 Intermediate Range Neutron Flux High Reactor Trip As Found Tolerance : 20.0 % RTP + 5.0 % RTP (Refs. 5.1, 5.16, 5.29, and 5.116)
The current Custom Technical Specification (CTS) LSSS value of < 40.0 % RTP is based on maintaining a Nominal Trip Setpoint value of 20.0 % RTP. The current Custom Technical Specification (CTS) LSSS value is non-conservative based on the COT error components of the Nuclear Instrumentation System. The Intermediate Range Neutron Flux High Reactor Trip function is not credited in the Kewaunee USAR Chapter 14 Safety Analysis (Ref. 5.1); therefore no Channel Statistical Allowance (CSA) Calculation has been performed for this function. The typical COT error allowance for this function is approximately 5.0 % RTP. For example, the COT error for this function at Surry is equal to + 5.678 % RTP, the COT error at North Anna is + 4.403 % RTP, and the typical Standardized Technical Specifications (STS) COT allowance is 5 % RTP (Refs. 5.3, 5.16, and 5.29). The As Found Tolerance will be < 25.0 % RTP. The As Found Tolerance of < 25.0 % RTP is based on maintaining a Nominal Trip Setpoint Value of 20.0 % RTP.
Note : This trip function is not credited in the USAR Chapter 14 Safety Analysis (Ref. 5.1). A CSA Calculation has not been performed for this function. Ref. 5.116 was used in the determination of the AFT and ALT below.
As Found Tolerance (AFT) = 20.0 % RTP + 5.0 % RTP As Left Tolerance (ALT) = 20.0% RTP + 4.9 % RTP(1)
(1) ALT = + (CSA2 - RD2) 1/2 = + (5.02 - 1.22) 1/2 = + 4.854 % RTP 4.5.6 Source Range Neutron Flux High Reactor Trip As Found Tolerance: 1.0 E5 CPS + 0.466 E5 CPS, - 0.318 E5 CPS (Refs. 5.1, 5.17, 5.30, and 5.117)
The current Custom Technical Specification (CTS) LSSS for this function states within Source Range span. The current Nominal Trip Setpoint for this function is 1.0 E5 Counts Per Second (CPS). The Source Range Neutron Flux High Reactor Trip function is not credited in the Kewaunee USAR Chapter 14 Safety Analysis (Ref. 5.1); therefore no Channel Statistical Allowance (CSA) Calculation has been performed for this function. The typical COT error allowance for this function is approximately + 3.0 %
of linear span. For example, the COT error for this function at Surry is equal to + 2.973 % of linear span and the COT error at North Anna is + 3.136 % of linear span (Refs. 5.17 and 5.30). To be conservative, the North Anna COT error allowance will be used in this analysis. The As Found Tolerance will be <
1.466 E5 CPS(1). The As Found Tolerance of < 1.466 E5 CPS is based on maintaining a Nominal Trip Setpoint Value of 1.0 E5 CPS.
Note : This trip function is not credited in the USAR Chapter 14 Safety Analysis (Ref. 5.1). A CSA Calculation has not been performed for this function. References 5.17, 5.30, and 5.117 were used in the determination of the AFT and ALT below.
As Found Tolerance (AFT) = 1.0 E5 CPS + 0.466 E5 CPS, - 0.318 E5 CPS(1)
As Left Tolerance (ALT) = 1.0 E5 CPS + 0.358 E5 CPS, - 0.264 E5 CPS(2)
EE-0116 Page 154 of 205 Revision 7 (1) Nominal Trip Setpoint = 1.0
- 105 CPS log 1.0
- 105 = 5.0 (on a 0 to 5.301 Decade scale)
COT error = + 3.136 % of linear span (3.136 %/100 %)
- 5.301 Decades = + 0.166239 Decade High Trip Setpoint = 5.0 + 0.166239 = 5.166239 antilog 5.166239 = 1.466
- 105 Low Trip Setpoint = 5.0 - 0.166239 = 4.833761 antilog 4.833761 = 0.682
- 105 (2) Nominal Trip Setpoint = 1.0
- 105 CPS log 1.0
- 105 = 5.0 (on a 0 to 5.301 Decade scale)
COT error minus Rack Drift = + 2.5 % of linear span (2.5 %/100 %)
- 5.301 Decades = + 0.133 Decade High Trip Setpoint = 5.0 + 0.133 = 5.133 antilog 5.133 = 1.358
- 105 Low Trip Setpoint = 5.0 - 0.133 = 4.867 antilog 4.867 = 0.736
- 105 4.5.7 Overtemperature T Reactor Trip As Found Tolerance: See below (Refs. 5.1, 5.90, 5.94, 5.105, 5.114, and 5.133)
The channel's maximum Trip Setpoint shall not exceed its computed Trip Setpoint by more than 2.0
% of the T span (Note that 2.0 % of the T span is equal to 3.0 % T Power)
The Overtemperature T (OTT) Reactor Trip Setpoint equation in terms of process units is:
1+t s OT TSP < T0 [ K1 - K2 * ( 1 + t s ) * (T - T') + K3 * (P - P') - f ( I)]
1 2
(Equation 4.5.7)
Where :
T0 = Indicated T at Rated Power, %
T = Average temperature, oF T = 573.0 oF P = Pressurizer pressure, psig P = 2235 psig K1 = 1.195 K2 = 0.015 / oF K3 = 0.00072 / psig I = qt - qb, where qt and qb are percent power in the top and bottom halves of the core respectively, and qt + qb is total core power in percent of rated power.
f(I) = function of I, percent of rated core power as shown in the Kewaunee COLR.
1 30.0 seconds 2 4.0 seconds The Overtemperature T (OTT) Reactor Trip Setpoint is variable and is constantly calculated based on actual plant conditions. For this reason, the Allowable Value cannot be expressed as a constant.
Further, the OTT Reactor Trip will only be analyzed for the following condition:
- OTT Reactor Trip with no FI
EE-0116 Page 155 of 205 Revision 7 The two conditions listed below are also associated with the OTT Reactor Trip. These conditions are not credited in the USAR Chapter 14 Safety Analysis and will not be analyzed here.
- OTT Reactor Trip with (+) FI
- OTT Reactor Trip with (-) FI Note: FI is the Delta Flux Penalty generated from the Upper and Lower Power Range Neutron Flux Detectors (i.e., QU and QL).
Subtracting the Total Loop Uncertainty (TLU) from the Analytical Limit (AL) yields the following Limiting Trip Setpoints (LTSP) for the OTT Reactor Trip with no FI condition as described above:
- LTSP for OTT Reactor Trip with no FI = 130.0 % - 8.403 % = 121.597 % T Power Subtracting the NON COT error components from the Analytical Limit yields the following Allowable Value (AV) for the OTT Reactor Trip with no FI contribution as described above:
- AV for OTT Reactor Trip with no FI = 130.0 % - 5.883 % = 124.117 % T Power For the most limiting condition (i.e., OTT Reactor Trip with no FI) the Actual Nominal Trip Setpoint of 118.25 % T Power (e.g., based on TAVG = 572.0 oF) is conservative with respect to the Limiting Trip Setpoint of 121.597 % T Power. The As Found Tolerance Value of 121.25 % T Power is conservative with respect to the Allowable Value of 124.117 % T Power. This As Found Tolerance Value of < 121.25 % T Power is based on maintaining a Nominal Trip Setpoint value of 118.25 % T Power. Note that this analysis is based on static conditions such that dynamic components are not considered.
The statistical combination of the COT and NON COT error components from CSA Calculation C11865 (Ref. 5.94) with the appropriate modifications described in Section 3.2 for the OTT Reactor Trip are given below. The COT and NON COT error components are used in Figure 4.5.7 to determine the Nominal Trip Setpoint (NTSP), Allowable Value (AV), As Found Tolerance (AFT), and As Left Tolerance (ALT) for the most limiting condition.
OTT Reactor Trip with no FI NON COTerror = SE1 + SE2 + SE3a + [PMA32 + PMA42 + PMA52 + PMA62 + PMA72 + PEA2 + (CSA3 NON 2 2 2 2 2 2 2 COT) + (CSA4 NON COT) + (CSA5 NON COT) + (CSA6 NON COT) + M7MTE + M18MTE + RTE1 +
2 2 1/2 RTE2 + RTE3 ]
Where the following terms are taken from Calculation C11865 (Ref. 5.94):
CSA3 NON COT = [(CSA1 NON COT)2 + (CSA2 NON COT)2 + (M3MTE)2 ] 1/2 CSA3 NON COT = (0.5482 + 0.5482 + 0.1732) 1/2 = 0.794 % of T span
EE-0116 Page 156 of 205 Revision 7 CSA4 NON COT = [(CSA1 NON COT
- 0.667)2 + (CSA2 NON COT
- 0.667)2 + (M4MTE)2 ] 1/2 CSA4 NON COT = [(0.548
- 0.667)2 +(0.548
- 0.667)2 + 0.2452) 1/2 = 0.572 % of T span CSA5 NON COT = (PEA2 + (SCA3 + SMTE3)2 + SD32 + SPE32 + STE32 + SPSE32 + M10MTE2)1/2 CSA5 NON COT = (0.02 + (0.096 + 0.150)2 +0.2882 + 0.02 + 0.8832 + 0.0612 + 0.02)1/2 = 0.963 % of T span CSA6a NON COT = (M15MTE2 + M16MTE2)1/2 CSA6a NON COT = (0.3462 + 0.2002)1/2 = 0.400 % of T span Thus, the total NON COTerror is equal to:
NON COTerror = 0.267 + 0.722 + 0.867 + [0.02 + 0.02 + 0.02 + 0.02 + 1.1332 + 0.02 + 0.7942 + 0.5722 +
0.9632 + 0.4002 + 0.3742 + 0.2242 + 0.52 + 0.52 + 0.52]1/2 NON COTerror = + 3.922 % of span = + 5.883 % T Power COTerror = (CSA3 COT2 + CSA4 COT2+ CSA5 COT2+ CSA6a COT2 + M72 + M182 + RD12 + RD22 + RD32)1/2 Where the following terms are taken from Calculation C11865 (Ref. 5.94):
CSA3 COT = [(CSA1 COT)2 + (CSA2 COT)2 + (M3)2 ] 1/2 CSA3 COT = (0.4172 + 0.4172 + 0.7072) 1/2 = 0.921 % of T span CSA4 COT = [(CSA1 COT
- 0.667)2 + (CSA2 COT
- 0.667)2 + M42] 1/2 CSA4 Cot = [(0.417
- 0.667)2 + (0.417
- 0.667)2 + 0.7072) 1/2 = 0.809 % of T span CSA5 COT = M10 CSA5 COT = 0.0 = 0.0 % of T span CSA6a COT = [(M15MTE)2 + (M16MTE)2]1/2 CSA6a COT = (0.5002 + 0.5002)1/2 = 0.707% of T span Thus, the COTerror is equal to:
COTerror = (0.9212 + 0.8092+ 0.02+ 0.7072 + 0.52 + 0.52 + 1.02 + 1.02 + 1.02)1/2 COTerror = + 2.346 % of T span = + 3.519 % T Power (The calculated COT error will be conservatively rounded back to + 2.0 % of T span = + 3.0 % T Power for the As Found Tolerance)
EE-0116 Page 157 of 205 Revision 7 Static As Found Tolerance (AFT) = Computed Setpoint + 3.0 % T Power Static As Left Tolerance (ALT) = Computed Setpoint + 2.4 % T Power (1)
(1) ALT = + (COTerror2 - RD12 - RD22 - RD32) 1/2 = + (2.3462 - 1.02 - 1.02 - 1.02) 1/2 ALT = + 1.582 % of T span = + 2.373 % T Power (round to + 2.4 % T Power)
KEWAUNEE'S OVERTEMPERATURE DELTA T REACTOR TRIP Analytical Limit (AL) 130.0 % Delta T Power TOTAL LOOP NON-COT ERRORS 5.883 % DT PWR 8.403 % DT Power UNCERTAINTY (TLU)
Allowable Value (AV) 2.520 % DT PWR 124.117 % Delta T Power COT ERRORS Limiting Trip Setpoint (LTSP) 121.597 % Delta T Power As Found Tolerance (AFT) 121.25 % Delta T Power COT ERRORS 3.00 % DT PWR SAFETY MARGIN 3.347 % DELTA T POWER Nominal Trip Setpoint (NTSP) 118.25 % Delta T Power OPERATING MARGIN 16.25 % DELTA T POWER High Operating Limit 102.00 % Delta T Power Nominal Operating Limit 100.00 % Delta T Power Figure 4.5.7
EE-0116 Page 158 of 205 Revision 7 4.5.8 Overpower T Reactor Trip As Found Tolerance: See below (Refs. 5.1, 5.90, 5.94, and 5.105)
" The channel's maximum Trip Setpoint shall not exceed its computed Trip Setpoint by more than 1.546 % of the T span " (Note that 1.525 % of the T span is equal to 2.288 % T Power)
The Overpower T Reactor Trip Setpoint is variable and is constantly calculated based on actual plant conditions. For this reason, the Allowable Value cannot be expressed as a constant. The Overpower T Reactor Trip is a backup reactor trip function and is not credited in the USAR Chapter 14 Safety Analysis (Ref. 5.1). The As Found Tolerance of + 1.525 % of T span = + 2.288 % T Power(1) is based on the COT error components from CSA Calculation (Ref. 5.94). The As Left Tolerance is based on the As Found Tolerance minus Rack Drift.
Static As Found Tolerance (AFT) = Computed Setpoint + 2.288 % T Power(1)
Static As Left Tolerance (ALT) = Computed Setpoint + 1.724 % T Power (2)
(1) The Overpower T Reactor Trip COT error is taken from Calculation C11865 (Ref. 5.94).
AFT = + (M12 + M22 + M32 + M42 + M52 + M62 + M172 + RD12 + RD22) 1/2 AFT = + (0.4172 + 0.4172 + 0.7072 + (0.707
- 0.667)2 + 0.0342 + 0.0342 + 0.52 + 1.02 + (1.0
- 0.069)2) 1/2 AFT = + 1.525 % of T span = + 2.288 % T Power (2) ALT = + (COTerror2 - RD12 - RD22) 1/2 = + (1.5252 - 1.02 - 0.0692) 1/2 ALT = + 1.149 % of T span = + 1.724 % T Power 4.5.9 Pressurizer Low Pressure Reactor Trip As Found Tolerance: 1904 PSIG + 10.0 PSIG (Refs. 5.1, 5.90, 5.93, and 5.105)
Adding the Total Loop Uncertainty (TLU) to the Analytical Limit (AL) yields a Limiting Trip Setpoint (LTSP) of 1858.82 PSIG. Adding the NON COT error components to the Analytical Limit yields an Allowable Value (AV) of 1855.94 PSIG. The Actual Nominal Trip Setpoint of 1904 PSIG is conservative with respect to the Limiting Trip Setpoint. The current Custom Technical Specification (CTS) LSSS value of > 1875 PSIG is conservative with respect to the Allowable Value. The current Custom Technical Specification (CTS) LSSS value of > 1875 PSIG is non-conservative based on the calculated COT error components determined in Calculation C10818 (Ref. 5.93). The LSSS value of >
1875 PSIG will be changed to an As Found Tolerance value of > 1894 PSIG to conform to the requirements of TSFT-493, Rev. 4 and RIS 2006-17. This As Found Tolerance is based on a Nominal Trip Setpoint value of 1904.0 PSIG. The Nominal Trip Setpoint value of 1904 PSIG will allow a 10.0 PSIG margin to be used for the COT error components. The As Found Tolerance value of > 1894 PSIG is sufficiently close enough to the calculated value using the CSA rack error terms from Calculation C10818 (Ref. 5.93).
The calculated As Found Tolerance for this function is > 1894.20 PSIG. The 0.20 PSIG offset is accommodated in the 45.18 PSIG Safety Margin for this trip as illustrated in Figure 4.5.9.
EE-0116 Page 159 of 205 Revision 7 The statistical combination of the COT and NON COT error components from CSA Calculation C10818 (Ref. 5.93) are given below. The COT and NON COT error components are used in Figure 4.5.9 to determine the Limiting Trip Setpoint (LTSP) and the Allowable Value (AV).
NON COTerror = SE + [PMA2 + PEA2 + (SCA+SMTE)2 + SD2 + SPE2 + STE2 + SPSE2 + M1MTE2 +
M2MTE2 + M3MTE2 + RTE2] 1/2 NON COTerror = 0.0 + [0.02 + 0.02 + (0.250 + 0.391)2 + 0.752 + 0.02 + 2.3002 + 0.1582 + 0.02 + 0.2002 +
0.2832 + 0.52]1/2 NON COTerror = + 2.580 % of span = + 20.64 PSIG COTerror = + (M12 + M22 + M32 + RD2) 1/2 COTerror = + (0.02 + 0.52 + 0.52 + 1.02) 1/2 COTerror = + 1.225 % of span = + 9.80 PSIG (round to + 10 PSIG)
As Found Tolerance (AFT) = 1904 PSIG + 10.0 PSIG As Left Tolerance (ALT) = 1904 PSIG + 5.7 PSIG(1)
See Figure 4.5.9 for specific details.
(1) ALT = + (COTerror2 - RD2) 1/2 = + (1.2252 - 1.02) 1/2 = + 0.71 % of span = + 5.7 PSIG
EE-0116 Page 160 of 205 Revision 7 KEWAUNEE'S PRESSURIZER LOW PRESSURE REACTOR TRIP Nominal Operating Limit 2235 PSIG Low Operating Limit 2210 PSIG OPERATING MARGIN 306 PSIG (Static)
Nominal Trip Setpoint (NTSP) 1904 PSIG COT ERRORS 10.00 PSIG SAFETY MARGIN 45.18 PSIG (Static)
As Found Tolerance (AFT) 1894.00 PSIG Limiting Trip Setpoint (LTSP) 1858.82 PSIG COT 2.88 PSIG TOTAL LOOP ERRORS 23.52 PSIG Allowable Value (AV) 1855.94 PSIG UNCERTAINTY (TLU)
NON-COT ERRORS 20.64 PSIG Analytical Limit (AL) 1835.3 PSIG Figure 4.5.9
EE-0116 Page 161 of 205 Revision 7 4.5.10 Pressurizer High Pressure Reactor Trip As Found Tolerance: 2377 PSIG + 9.0 PSIG (Refs. 5.1, 5.90, 5.93, and 5.105)
Subtracting the Total Loop Uncertainty (TLU) from the Analytical Limit (AL) yields a Limiting Trip Setpoint (LTSP) of 2387.64 PSIG. Subtracting the NON COT error components from the Analytical Limit yields an Allowable Value (AV) of 2389.78 PSIG. The Actual Nominal Trip Setpoint of 2377 PSIG is conservative with respect to the Limiting Trip Setpoint. The current Custom Technical Specification (CTS) LSSS value < 2385 PSIG is conservative with respect to the Allowable Value. The CTS LSSS value < 2385 PSIG will be revised to an As Found Tolerance Value of < 2386 PSIG based on the COT error components calculated below. The revised As Found Tolerance Value of < 2386 PSIG is also conservative with respect to the Allowable Value, however it is slightly non-conservative with respect to the calculated value using the CSA rack error components from Calculation C10818 (Ref 5.93). The calculated As Found Tolerance Value for this function is < 2385.94 PSIG. The 0.06 PSIG offset from the calculated value is accommodated within the Safety Margin for this function (i.e., 10.64 PSIG). The As Found Tolerance value of < 2386 PSIG is based on the Nominal Trip Setpoint value of 2377.0 PSIG.
The statistical combination of the COT and NON COT error components from CSA Calculation C10818 (Ref. 5.93) are given below. The COT and NON COT error components are used in Figure 4.5.10 to determine the Limiting Trip Setpoint (LTSP) and the Allowable Value (AV).
NON COTerror = SE + [PMA2 + PEA2 + (SCA+SMTE)2 + SD2 + SPE2 + STE2 + SPSE2 + M1MTE2 +
M2MTE2 + RTE2] 1/2 NON COTerror = 0.0 + [0.02 + 0.02 + (0.250 + 0.391)2 + 0.752 + 0.02 + 2.3002 + 0.1582 + 0.02 + 0.2002 +
0.52]1/2 NON COTerror = + 2.565 % of span = + 20.52 PSIG COTerror = + (M12 + M22 + RD2) 1/2 COTerror = + (0.02 + 0.52 + 1.02) 1/2 COTerror = + 1.118 % of span = + 8.944 PSIG (round to + 9.0 PSIG)
As Found Tolerance (AFT) = 2377 PSIG + 9.0 PSIG As Left Tolerance (ALT) = 2377 PSIG + 4.0 PSIG(1)
See Figure 4.5.10 for specific details.
(1) ALT = + M2 = + 0.5 % of span = + 4.0 PSIG
EE-0116 Page 162 of 205 Revision 7 KEWAUNEE'S PRESSURIZER HIGH PRESSURE REACTOR TRIP Analytical Limit (AL) 2410.3 PSIG NON-COT ERRORS 20.52 PSIG TOTAL LOOP 22.66 PSIG Allowable Value (AV)
UNCERTAINTY (TLU) 2389.78 PSIG COT ERRORS 2.14 PSIG Limiting Trip Setpoint (LTSP) 2387.64 PSIG As Found Tolerance (AFT)
SAFETY MARGIN COT ERRORS 2386.00 PSIG 9.00 PSIG 10.64 PSIG Nominal Trip Setpoint (NTSP) 2377 PSIG OPERATING MARGIN 117 PSIG High Operating Limit 2260 PSIG Nominal Operating Setpoint 2235 PSIG Figure 4.5.10
EE-0116 Page 163 of 205 Revision 7 4.5.11 Reactor Coolant Flow Low Reactor Trip (Normalized)
Allowable Value: As Found Tolerance = 93% Flow + 1.1% Flow (Refs. 5.1, 5.90, 5.96, 5.106, and 5.120)
Adding the Total Loop Uncertainty (TLU) to the Analytical Limit (AL) yields a Limiting Trip Setpoint (LTSP) of 90.52 % Flow. Adding the NON COT error components to the Analytical Limit yields an Allowable Value (AV) of 90.27 % Flow. The current Nominal Trip Setpoint of 93.0 % Flow is conservative with respect to the Limiting Trip Setpoint and the current Custom Technical Specification (CTS) LSSS value of > 90.0 % Flow is non conservative with respect to the Allowable Value. The CTS LSSS value > 90.0 % Flow will be changed to an As Found Tolerance value of > 91.9 % Flow based on the calculated value using the CSA rack error terms from Calculation C10819 (Ref 5.96). The As Found Tolerance of > 91.9 % Flow is conservative and conforms to the methodology described in TSFT-493, Rev. 4 and RIS 2006-17.
The calculated As Found Tolerance Value for this function is > 91.853 % Flow. The 0.047 % Flow offset will be negated resulting in a conservative As Found Tolerance value of > 91.9 % Flow for this trip as illustrated in Figure 4.5.11.
The statistical combination of the COT and NON COT error components from CSA Calculation C10819 (Ref. 5.96) are given below. The COT and NON COT error components are used in Figure 4.5.11 to determine the Limiting Trip Setpoint (LTSP) and the Allowable Value (AV).
NON COTerror (P span) = [(SCA+SMTE)2 + SD2 + SPE2 + STE2 + SPSE2 +
M2MTE2]1/2 NON COTerror (P span) = [(0.250 + 0.110)2 + 0.502 + 0.02 + 0.7132 + 0.1102 + 0.2002]1/2 NON COTerror (P span) = + 0.970 % of P span = + 0.574 % of Flow span @ 93 % Flow(1)
NON COTerror (Flow span) = SE + (PMA2 + PEA2 + RTE2) 1/2 NON COTerror (Flow span) = 0.372 + (2.4552 + 0.4552 + 0.52) 1/2 NON COTerror (Flow span) = 2.918 % of Flow span TOTAL NON COTerror (Flow span) = (2.9182 + 0.5742) 1/2 = 2.974 % of Flow span = 3.271 % Flow @
93.0 % Flow (e.g., the Nominal Trip Setpoint).
COTerror (P span ) = + M2 COTerror (P span ) = + 0.50 % of P span COTerror (P span) = + 0.50 % of P span = + 0.296 % of Flow span @ 93 % Flow = + 0.326 % Flow(1)
COTerror (Flow span) = RD = + 1.0 % of Flow span = + 1.10 % Flow
EE-0116 Page 164 of 205 Revision 7 TOTAL COTerror (Flow span) = (0.2962 + 1.02) 1/2
= 1.043 % of Flow span = 1.147 % Flow @ 93.0 %
Flow (e.g., the Nominal Trip Setpoint) (1)
As Found Tolerance (AFT) = 93% Flow + 1.1% Flow(1)
As Left Tolerance (ALT) = 93% Flow + 0.55% Flow(2)
See Figure 4.5.11 for specific details.
KEWAUNEE'S REACTOR COOLANT LOW FLOW REACTOR TRIP Nominal Operating Limit 100 % Flow OPERATING MARGIN 7.0 % Flow Nominal Trip Setpoint (NTSP) 93.0 % Flow COT ERRORS 1.1 % Flow SAFETY MARGIN 2.485 % Flow As Found Tolerance (AFT) 91.9 % Flow Limiting Trip Setpoint (LTSP) 90.515 % Flow COT ERRORS 0.244 %
TOTAL LOOP Flow 3.515 % Flow Allowable Value (AV)
UNCERTAINTY (TLU) 90.271 % Flow NON-COT ERRORS 3.271 % Flow Analytical Limit (AL) 87.0 % Flow Figure 4.5.11 (1) The equation to convert % P error to % Flow error is: % flow span = (P uncertainty)
- 0.5 * (flow max / flow x) (Ref. 5.120)
(2) The calculated As Left Tolerance is + 0.296 % of Flow Span. This tolerance is too restrictive and will be set at + 0.5 % of Flow Span (i.e., like all other Bistable tolerances). The + 0.204 % of Flow Span offset is accommodated in the Safety Margin of 2.485
% Flow = 2.259 % of Flow Span.
EE-0116 Page 165 of 205 Revision 7 4.5.12 Reactor Coolant Pump Undervoltage As Found Tolerance: 76.667 + 0.885 % of normal voltage = 92 + 1.06 VAC (Refs. 5.1, 5.90, 5.127, and 5.128)
The current Custom Technical Specification (CTS) LSSS for this function is > 75 % of normal voltage.
The current Nominal Trip Setpoint for this function is 91 to 93 VAC where 92 VAC is the centerline voltage = 76.667 % of voltage span (Ref. 5.127). This analysis assumes that 120 VAC from the potential transformer is equal to 100 % of bus voltage/normal voltage which is equal to 4160 VAC. The Reactor Coolant Pump Undervoltage Trip function is not credited in the Kewaunee USAR Chapter 14 Safety Analysis (Ref. 5.1); however a Channel Statistical Allowance (CSA) Calculation has been performed for this function. The calibration accuracy for this trip function is 92 + 1.0 VAC = 76.667 + 0.833 % of normal voltage (Ref. 5.127). The COT error from Calculation C11891 is + 1.06 VAC = + 0.885 % of normal voltage. Therefore, the As Found Tolerance for the Reactor Coolant Pump Undervoltage Trip is 76.667 + 0.885 % of normal voltage = 92 + 1.06 VAC based on device calibration accuracy and drift from Reference 5.128. The As Left Tolerance for the Reactor Coolant Pump Undervoltage Trip is 76.667 + 0.833 % of normal voltage = 92 + 1.0 VAC based on the device calibration accuracy from Reference 5.127. The As Found and As Left Tolerances are based on maintaining a Nominal Trip Setpoint Value 92 VAC = 76.667 % of normal voltage.
As Found Tolerance (AFT) = 76.667 + 0.885 % of normal voltage = 92 + 1.06 VAC(1)
As Left Tolerance (ALT) = 76.667 + 0.833 % of normal voltage = 92 + 1.0 VAC(2)
(1) AFT = + (SCA2 + SD2) 1/2 = + (0.8332 + 0.3002) 1/2 = + 0.885 % of normal voltage = + 1.06 VAC (2) ALT = + SCA = + 0.833 % of normal voltage = + 1.0 VAC 4.5.13 Reactor Coolant Pump Underfrequency As Found Tolerance: 57 + 0.3 Hz (Refs. 5.1, 5.90, 5.126, and 5.127)
The current Custom Technical Specification (CTS) LSSS for this function is > 55.0 Hz. The current Nominal Trip Setpoint for this function is 57 + 0.1 Hz (Ref. 5.127). The Reactor Coolant Pump Underfrequency Trip function is not credited in the Kewaunee USAR Chapter 14 Safety Analysis (Ref.
5.1); however a Channel Statistical Allowance (CSA) Calculation has been performed for this function.
Based on Calculation C11890 (Ref. 5.126), the COT error allowance for this function is + 0.3 Hz. The calibration accuracy for this trip function is + 0.1 Hz (Ref. 5.127). The As Found Tolerance of 57 + 0.3 Hz is based on the COT error from Calculation C11890 and the As Left Tolerance of 57 + 0.1 Hz is conservatively based on device calibration accuracy from Reference 5.127. The As Found and As Left Tolerances are based on maintaining a Nominal Trip Setpoint Value of 57 Hz.
As Found Tolerance (AFT) = 57 + 0.3 Hz(1) (3)
As Left Tolerance (ALT) = 57 + 0.1 Hz(2)
(1) AFT = + (SCA2 + SD2) 1/2 = + (6.662 + 0.6672) 1/2 = + 6.69 % of frequency span or (6.69% /100%) x 4.5 Hz(3) = + 0.3 Hz (2) ALT = Current Calibration Accuracy from Reference 5.127 = + 0.1 Hz (3) The frequency span of 4.5 Hz is taken from Calculation C11890 (Ref. 5.126).
EE-0116 Page 166 of 205 Revision 7 4.5.14 Pressurizer High Level Reactor Trip As Found Tolerance: 85.0 % Level + 1.12 % Level (Refs. 5.1, 5.90, 5.92, and 5.109)
The current Custom Technical Specification (CTS) LSSS for this function is < 90.0 % Level. The current Nominal Trip Setpoint for this function is 85.0 % Level (Ref. 5.109). The Pressurizer High Level Reactor Trip function is not credited in the Kewaunee USAR Chapter 14 Safety Analysis (Ref.
5.1); however a Channel Statistical Allowance (CSA) Calculation has been performed for this function.
Based on Calculation C10982 (Ref. 5.92), the COT error allowance for this function is + 1.118 % of span = + 1.118 % Level. The calibration accuracy for this trip function is + 0.5 % of span = + 0.5 %
Level (Ref. 5.109). The As Found Tolerance based on the COT error from Calculation C10982 is 85 +
1.118 % Level (round to 85 + 1.12 % Level). The As Left Tolerance is 85 + 0.5 % Level is based on device calibration accuracy from Reference 5.109. The As Found and As Left Tolerances are based on maintaining a Nominal Trip Setpoint Value of 85 % Level.
As Found Tolerance (AFT) = 85.0 % Level + 1.12 % Level(1)
As Left Tolerance (ALT) = 85.0 % Level + 0.5 % Level(2)
(1) AFT = + (M22 + RD2) 1/2 = + (0.52 + 1.02) 1/2 = + 1.118 % span = + 1.118 % Level (2) ALT = + M2 = + 0.5 % span = + 0.5 % Level 4.5.15 Steam Generator Water Level Low Low Reactor Trip / Auxiliary Feedwater Initiation As Found Tolerance: 17.0 % Level + 1.12 % Level (Refs. 5.1, 5.90, 5.97, 5.112, and 5.134)
Note: The Analytical Limit for this function is 0.0 % NR Level (Ref. 5.1). The Channel Statistical Allowance (CSA) for this function has a large negative Process Measurement Accuracy (PMA) bias term which results in a negative CSA value. For conservatism, the absolute value of the larger CSA value from Reference 5.97 will be used in this analysis.
Adding the Total Loop Uncertainty (TLU) to the Analytical Limit (AL) yields a Limiting Trip Setpoint (LTSP) of 4.496 % NR Level. Adding the NON COT error components to the Analytical Limit yields an Allowable Value (AV) of 4.087 % NR Level. The Actual Nominal Trip Setpoint of 17.0 % NR Level (Ref. 5.112) is conservative with respect to the Limiting Trip Setpoint and the current Custom Technical Specification (CTS) LSSS value of > 5.0 % NR Level is conservative with respect to the Allowable Value. The CTS LSSS value of > 5.0 % NR Level is non-conservative based on the calculated COT error components determined in Calculation C11116 (Ref. 5.97). The CTS LSSS value of > 5.0 % NR Level will be changed to an As Found Tolerance value of > 15.88 % NR Level to conform to the requirements of TSFT-493, Rev. 4 and RIS 2006-17. The As Found Tolerance Value of
> 15.88 % NR Level is based on maintaining a Nominal Trip Setpoint value of 17.0 % NR Level.
The statistical combination of the COT and NON COT error components from CSA Calculation C11116 (Ref. 5.97) are given below. The COT and NON COT error components are used in Figure 4.5.15 to determine the Limiting Trip Setpoint (LTSP) and the Allowable Value (AV).
EE-0116 Page 167 of 205 Revision 7 NON COTerror = PMA2 + (PEA2 + (SCA+SMTE)2 + SD2 + SPE2 + STE2 + SPSE + M1MTE2 +
M3MTE2 + RTE2) 1/2 NON COTerror = 2.518 + [0.02 + (0.250+0.217)2 + 0.2802 + 0.5772 + 1.2412 + 0.0602 + 02 + 0.2002 +
0.52]1/2 NON COTerror = + 4.087 % of span = + 4.087 % NR Level (worst case).
COTerror = + (M12 + M32 + RD2) 1/2 COTerror = + (0.02 + 0.52 + 1.02) 1/2 COTerror = + 1.118 % of span = + 1.118 % NR Level (round to + 1.12 % NR Level)
As Found Tolerance (AFT) = 17.0 % Level + 1.12 % Level(1)
As Left Tolerance (ALT) = 17.0 % Level + 0.5 % Level(2)
See Figure 4.5.15 for specific details.
(1) AFT = + (M32 + RD2) 1/2 = + (0.52 + 1.02) 1/2 = + 1.118 % span = + 1.118 % Level (round to + 1.12 % NR Level)
(2) ALT = + M3 = + 0.5 % span = + 0.5 % Level
EE-0116 Page 168 of 205 Revision 7 KEWAUNEE'S STEAM GENERATOR LO-LO LEVEL REACTOR TRIP Nominal Operating Limit 44.0 % NR Level Low Operating Limit 39.0 % NR Level OPERATING MARGIN 22.0 % NR Level Nominal Trip Setpoint (NTSP) 17.0 % NR Level COT ERRORS 1.12 % NR Level SAFETY MARGIN 12.504 % NR Level As Found tolerance (AFT) 15.88 % NR Level Limiting Trip Setpoint (LTSP) 0.409 % NR Level 4.496 % NR Level COT ERRORS TOTAL LOOP 4.496 % NR Level Allowable Value (AV) 4.087 % NR Level UNCERTAINTY (TLU)
NON-COT ERRORS 4.087 % NR Level Analytical Limit (AL) 0.0 % NR Level Figure 4.5.15
EE-0116 Page 169 of 205 Revision 7 4.5.16 Steam Generator Water Level Low Coincident Reactor Trip As Found Tolerance: 25.5 % Level + 1.12 % NR Level (Refs. 5.1, 5.90, 5.97, and 5.112)
The Steam Generator Water Level Low Coincident Reactor Trip is not addressed in the current version of Kewaunees Custom Technical Specifications (CTS). This function will now be included in the Setpoint Control Program based on the requirements of ITS Table 3.3.1-1, item 15. The current Nominal Trip Setpoint for this function is 25.5 % NR Level (Ref. 5.112). The Steam Generator Water Level Low Coincident Trip function is not credited in the Kewaunee USAR Chapter 14 Safety Analysis (Ref. 5.1); however a Channel Statistical Allowance (CSA) Calculation has been performed for this function. Based on Calculation C11116 (Ref. 5.97), the COT error allowance for this function is +
1.118 % of span = + 1.118 % NR Level. The calibration accuracy for this trip function is + 0.5 % of span = + 0.5 % Level (Ref. 5.112). The As Found Tolerance based on the COT error from Calculation C11116 is 25.5 + 1.118 % NR Level (round to 25.5 + 1.12 % NR Level). The As Left Tolerance is 25.5
+ 0.5 % NR Level is based on the device calibration accuracy from Reference 5.112. The As Found and As Left Tolerances are based on maintaining a Nominal Trip Setpoint Value of 25.5 % NR Level.
As Found Tolerance (AFT) = 25.5 % Level + 1.12 % NR Level(1)
As Left Tolerance (ALT) = 25.5 % Level + 0.5 % NR Level(2)
(1) AFT = + (M22 + RD2) 1/2 = + (0.52 + 1.02) 1/2 = + 1.118 % span = + 1.118 % NR Level (2) ALT = + M2 = + 0.5 % span = + 0.5 % NR Level 4.5.17 Steam Flow Feed Flow Mismatch Coincident Reactor Trip As Found Tolerance: 0.87
- 106 PPH + 0.063
- 106 PPH (Refs. 5.1, 5.90, 5.98, 5.108, and 5.130)
The Steam Flow Feed Flow Mismatch Coincident Reactor Trip is not addressed in the current version of Kewaunees Custom Technical Specifications (CTS). This function will now be included in the Setpoint Control Program based on the requirements of ITS Table 3.3.1-1, item 15. The current Nominal Trip Setpoint for this function is 0.87
- 106 Pound Per Hour (PPH) (Ref. 5.108). Based on Reference 5.108, the maximum Steam and Feedwater flowrate is 4.47
- 106 PPH and the nominal flowrate at 100 % power (i.e., Flownom) is 3.82
- 106 PPH (Ref. 5.98). This means that the current Nominal Trip Setpoint is set at 22.77 % of Flownom. The Steam Flow Feed Flow Mismatch Coincident Reactor Trip function is not credited in the Kewaunee USAR Chapter 14 Safety Analysis (Ref. 5.1) and a Channel Statistical Allowance (CSA) Calculation has not been performed for this function. The COT error allowance for this function will be based on the applicable module calibration accuracies given in Reference 5.108 and the standard + 1.0 % of span Rack Drift (RD) value from Reference 5.5. Based on References 5.108 and 5.130, there are four modules with calibration accuracies that develop this trip function. The COT error allowance based on References 5.5 and 5.108 is + 1.414 % of Flow Span = +
0.063
- 106 PPH (1). The As Found Tolerance based on References 5.5, 5.108, and 5.130 is 0.87
- 106 PPH + 0.063
- 106 PPH. The As Left Tolerance based on calibration accuracy of the four devices from Reference 5.108 is 0.87
- 106 PPH + 0.045
- 106 PPH. The As Found and As Left Tolerances are based on maintaining a Nominal Trip Setpoint Value of 0.87
- 106 PPH.
EE-0116 Page 170 of 205 Revision 7 As Found Tolerance (AFT) = 0.87
- 106 PPH + 0.063
- 106 PPH (1)
As Left Tolerance (ALT) = 0.87
- 106 PPH + 0.045
- 106 PPH (2)
(1) AFT = + (FM-466A2 + FC-466B/C2 + FM-464A2 + FM-464B2 + RD2) 1/2 AFT = + (0.52 + 0.52 + 0.52 + 0.52 + 1.02) 1/2 = + 1.414 % of Flow Span = + 0.063
- 106 PPH (2) ALT = + (FM-466A2 + FC-466B/C2 + FM-464A2 + FM-464B2) 1/2 ALT = + (0.52 + 0.52 + 0.52 + 0.52) 1/2 = + 1.00 % of Flow Span = + 0.0447
- 106 PPH (round to + 0.045
- 106 PPH) 4.5.18 Turbine Trip Low Fluid Oil Pressure As Found Tolerance: 45.0 PSIG + 0.5 PSIG (Refs. 5.1 and 5.144)
The current Custom Technical Specifications (CTS) does not address the Turbine Trip Low Fluid Oil Pressure function. Improved Technical Specifications (ITS) has added this function to ITS Table 3.3.1-
- 1. Based on Reference 5.144, the current Nominal Trip Setpoint for Turbine Trip Low Fluid Oil Pressure is 45.0 PSIG (decreasing). The Turbine Trip Low Fluid Oil Pressure function is not credited in the Chapter 14 Safety Analysis (Ref. 5.1). Based on Reference 5.144, the calibration accuracy for the pressure switch is + 0.5 PSIG. For this application, the As Found Tolerance and As Left Tolerance will be set at the same value, i.e., + 0.5 PSIG.
As Found Tolerance (AFT) = 45.0 PSIG + 0.5 PSIG As Left Tolerance (ALT) = 45.0 PSIG + 0.5 PSIG (1) AFT = Calibration Procedure Setpoint = + 0.5 PSIG ( Reference 5.144)
(2) ALT = Calibration Procedure Setpoint = + 0.5 PSIG ( Reference 5.144)
Note: Reference 5.144 is applicable in CTS. The procedure is being converted for ITS and will become MA-KW-ISP-TB-001, Revsion 0, TB-Turbine Pressure Switches and Indicators Calibration.
4.5.19 Safety Injection (SI) Input from Engineered Safety Features Actuation System (ESFAS)
See Section 4.6.
EE-0116 Page 171 of 205 Revision 7 Reactor Trip Permissives Note : Only the limiting As Found Tolerance value will be addressed in analysis for each Reactor Trip Permissive described below.
4.5.20 Permissive P-6, Intermediate Range Neutron Flux As Found Tolerance: Permissive P-6 unblock should occur between 1
- 10-5% Rated Power and 1.27
- 10-5% Rated Power (Refs. 5.1, 5.90, and 5.116)
The current Custom Technical Specification (CTS) LSSS for this function is > 10-5% Rated Power. The current Nominal Trip Setpoint for this function is set equal to the CTS LSSS value, i.e., 1
- 10-5% Rated Power. Permissive P-6 is not credited in the Kewaunee USAR Chapter 14 Safety Analysis (Ref. 5.1) and a Channel Statistical Allowance (CSA) calculation has not been performed for this function. The COT error allowance for this function will be based on a portion of the calibration accuracy for the Intermediate Range Front Panel Meter at the nominal unblock trip setpoint value of 1
- 10-5% Rated Power, i.e., 7.9
- 10-6% Rated Power to 1.27
- 10-5% Rated Power as specified in Reference 5.116.
Only the high end of the tolerance value will be used to develop the As Found Tolerance for this function such that the current CTS LSSS value of 10-5% Rated Power will be the low end of the tolerance. The As Found Trip for Permissive P-6 should occur between 1
- 10-5% Rated Power and 1.27
- 10-5% Rated Power. Since this As Found Tolerance does not include a Rack Drift value, the As Left Tolerance will be equal to the As Found Tolerance.
As Found Tolerance (AFT) = Permissive P-6 unblock should occur between 1
- 10-5% Rated Power and 1.27
- 10-5% Rated Power As Left Tolerance (ALT) = Permissive P-6 unblock should occur between 1
- 10-5% Rated Power and 1.27
- 10-5% Rated Power 4.5.21 Permissive P-7, Block Low Power Reactor Trips and Enable High Power Trips P-10 As Found Tolerance (AFT) = 11.0 % RTP + 1.2 % RTP P-13 As Found Tolerance (AFT) = 8.8 % Turbine Load + 1.25 % Turbine Load (Refs. 5.1, 5.90, 5.91, 5.104, and 5.132)
The current Custom Technical Specification (CTS) LSSS for Permissive P-7 is < 12.2 % of Rated Power for both inputs, i.e., P-10 and P-13. Permissive P-7 is not credited in the Kewaunee USAR Chapter 14 Safety Analysis (Ref. 5.1); however, a Channel Statistical Allowance (CSA) Calculation has been performed for Permissive P-10. Permissive P-7 is made up of input signals from Turbine First Stage Pressure (P-13) and NIS Power Range (P-10). Signals to the P-7 and P-10 permissives are supplied from the same bistables in the NIS Power Range drawers. P-7 and P-10 will both enable and block functions from the trip and reset points of these bistables. The calibration procedure (Ref. 5.104) for the NIS Power Range P-10 unblock input into Permissive P-7 sets the Nominal Trip Setpoint at 11.0
% RTP (increasing). The current Nominal Trip Setpoint for the Turbine First Stage Pressure input to P-7, i.e., P-13 is 8.8 % of Turbine Load (e.g., based on a nominal Turbine First Stage Pressure value of 583.5 PSIG @ 100 % Power). The COT error associated with P-10 taken from Calculation C11705 (Ref. 5.91) is + 1.085 % of span = + 1.3 % RTP (round back to + 1.2 % RTP)(1). The COT error
EE-0116 Page 172 of 205 Revision 7 associated with P-13 is + 1.12 % of span = + 1.25 % Turbine Load based on the P-13 Bistable calibration accuracy from Reference 5.132 and the standard Rack Drift (RD) error value from Reference 5.5(3). The As Found Tolerance for the P-10 input to P-7 is 11.0 + 1.2 % RTP(1). The As Left Tolerance for the P-10 input to P-7 is 11.0 + 0.5 % RTP(2). The As Found Tolerance for the P-13 input to P-7 is 8.8 + 1.25 % Turbine Load(3). The As Left Tolerance for the P-13 input to P-7 is 8.8 + 0.56 % Turbine Load(4).
P-10 As Found Tolerance (AFT) = 11.0 % RTP + 1.2 % RTP(1)
P-10 As Left Tolerance (ALT) = 11.0 % RTP + 0.5 % RTP(2)
P-13 As Found Tolerance (AFT) = 8.8 % Turbine Load + 1.25 % Turbine Load(3)
P-13 As Left Tolerance (ALT) = 8.8 % Turbine Load + 0.56 % Turbine Load(4)
(1) AFT = + (M12 + M52 + RD2) 1/2 = + (0.052 + 0.4172 + 1.02) 1/2 = + 1.085 % of span = + 1.3 % RTP. This COT error will be rounded back to + 1.2 % RTP to conform to the current CTS LSSS of < 12.2 % RTP (i.e., 11 % + 1.2 % is < 12.2 %)
(2) ALT = + (M12 + M52) 1/2 = + (0.052 + 0.4172) 1/2 = + 0.42 % of span = + 0.5 % RTP.
(3) AFT = + (PC-466A2 + RD2) 1/2 = + (0.52 + 1.02) 1/2 = + 1.12 % of span. The range of the Turbine First Stage Pressure Transmitters is 0 to 650 PSIG and the nominal 100 % Power pressure is 583.5 PSIG. (1.12 %/100 %)*650 PSIG = 7.28 PSIG. Then, (7.28 PSIG/583.5 PSIG)
- 100 % Turbine Load = 1.25 % Turbine Load.
(4) ALT = + 0.5 % of span = (0.5 %/100 %)*650 PSIG = 3.25 PSIG. Then, (3.25 PSIG/583.5 PSIG)
- 100 % Turbine Load =
0.56 % Turbine Load.
4.5.22 Permissive P-8, Power Range Neutron Flux As Found Tolerance (AFT) = 9.5 % RTP + 1.3 % RTP (Refs. 5.1, 5.90, 5.91, and 5.104)
The current Custom Technical Specification (CTS) LSSS for Permissive P-8 is < 10.0 % of Rated Power. The Nominal Trip Setpoint for the unblock portion of Permissive P-8 is 9.5 % RTP (Ref. 5.104).
Permissive P-8 is not credited in the Kewaunee USAR Chapter 14 Safety Analysis (Ref. 5.1) and a Channel Statistical Allowance (CSA) Calculation has not been performed for this function. However, CSA Calculation C11705 (Ref. 5.91) has identified the COT error components associated with Permissive P-10 which uses identical circuitry to that of Permissive P-8 to generate their respective functions. The COT error associated with Permissive P-10, taken from Calculation C11705 (Ref. 5.91),
is + 1.085 % of span = + 1.3 % RTP(1). This COT error is also applicable for Permissive P-8 and will be used to develop the As Found Tolerance. Based on a Nominal Trip Setpoint of 9.5 % RTP and a COT error of + 1.3 % RTP, the As Found Tolerance for Permissive P-8 is 9.5 + 1.3 % RTP. Note that the high end of the As Found Tolerance (i.e., 9.5 % RTP + 1.3 % RTP = 10.8 % RTP) is non-conservative with respect to the current CTS LSSS of < 10 % RTP, however this As Found tolerance is acceptable because there is no specific Analytical Limit associated with this permissive. The As Left Tolerance will be equal to the COT error minus Rack Drift (RD)(2). The As Found and As Left Tolerance are based on maintaining a Nominal Trip Setpoint of 9.5 % RTP.
As Found Tolerance (AFT) = 9.5 % RTP + 1.3 % RTP(1)
As Left Tolerance (ALT) = 9.5 % RTP + 0.5 % RTP(2)
(1) AFT = + (M12 + M52 + RD2) 1/2 = + (0.052 + 0.4172 + 1.02) 1/2 = + 1.085 % of span = + 1.3 % RTP.
(2) ALT = + (M12 + M52) 1/2 = + (0.052 + 0.4172) 1/2 = + 0.42 % of span = + 0.5 % RTP.
Note: The error terms used above are from Calculation C11705 (Ref. 5.91) and they are used for Permissive P-10.
EE-0116 Page 173 of 205 Revision 7 4.5.23 Permissive P-10, Power Range Neutron Flux Unblock Low Power Reactor Trips and Block High Power Trips As Found Tolerance (AFT) = 9.0 % RTP + 1.3 % RTP (Refs. 5.1, 5.90, 5.91, and 5.104)
The current Custom Technical Specification (CTS) LSSS for Permissive P-10 (i.e., unblock the low power trips) is > 7.8 % of Rated Power. The calibration procedure (Ref. 5.104) for the NIS Power Range P-10 unblock of the low power trips sets the Nominal Trip Setpoint at 9.0 % RTP (decreasing).
Permissive P-10 is not credited in the Kewaunee USAR Chapter 14 Safety Analysis (Ref. 5.1); however, a Channel Statistical Allowance (CSA) Calculation has been performed for this function. Based on Reference 5.91, the COT error associated with P-10 is + 1.085 % of span = + 1.3 % RTP(1). This COT error will be used to develop the As Found Tolerance for this function. Based on a Nominal Trip Setpoint of 9.0 % RTP and a COT error of + 1.3 % RTP, the As Found Tolerance for Permissive P-10 is 9.0 + 1.3 % RTP. Note that the low end of the As Found Tolerance (i.e., 9.0 % RTP - 1.3 % RTP = 7.7
% RTP) is non-conservative with respect to the current CTS LSSS of > 7.8 % RTP, however this As Found tolerance is acceptable because there is no specific Analytical Limit associated with this permissive. The As Left Tolerance will be equal to the COT error minus Rack Drift (RD)(2). The As Found and As Left Tolerance are based on maintaining a Nominal Trip Setpoint of 9.0 % RTP.
As Found Tolerance (AFT) = 9.0 % RTP + 1.3 % RTP(1)
As Left Tolerance (ALT) = 9.0 % RTP + 0.5 % RTP(2)
(1) AFT = + (M12 + M52 + RD2) 1/2 = + (0.052 + 0.4172 + 1.02) 1/2 = + 1.085 % of span = + 1.3 % RTP.
(2) ALT = + (M12 + M52) 1/2 = + (0.052 + 0.4172) 1/2 = + 0.42 % of span = + 0.5 % RTP.
EE-0116 Page 174 of 205 Revision 7 4.6 Limiting Trip Setpoints, Allowable Values, As Found Tolerances, and As Left Tolerances for Kewaunee Engineered Safety Features Actuation System (ESFAS) Instrumentation to support the Setpoint Control Program Note: Only the limiting As Found Tolerance value will be addressed in analysis for each ESFAS Trip Function described below.
4.6.1 Safety Injection, Manual Initiation As Found Tolerance: There is no specific ESFAS Trip Setpoint associated with this function.
4.6.2 High Containment Pressure - Safety Injection As Found Tolerance: As Found Tolerance = 3.6 PSIG + 0.335 PSIG (Refs. 5.1, 5.90, 5.95, 5.110, and 5.111)
Subtracting the Total Loop Uncertainty (TLU) from the Analytical Limit (AL) yields a Limiting Trip Setpoint (LTSP) of 4.237 PSIG. Subtracting the NON COT error components from the Analytical Limit yields an Allowable Value (AV) of 4.328 PSIG. The current CTS Setting Limit for this function is < 4.0 PSIG. The CTS Setting Limit for this function of < 4.0 PSIG is conservative with respect to the Allowable Value, however it is non-conservative with respect to the calculated As Found Tolerance value of 3.6 PSIG + 0.335 PSIG (i.e., 3.935 PSIG) . The Actual Nominal Trip Setpoint of 3.6 PSIG is conservative with respect to the Limiting Trip Setpoint. The CTS Setting Limit of < 4.0 PSIG will be changed to an As Found Tolerance value of 3.6 PSIG + 0.335 PSIG to conform to the requirements of TSFT-493, Rev. 4 and RIS 2006-17.
The statistical combination of the COT and NON COT error components from CSA Calculation C11006 (Ref. 5.95) are given below. The COT and NON COT error components are used in Figure 4.6.2 to determine the Limiting Trip Setpoint (LTSP) and the Allowable Value (AV).
NON COTerror = [PMA2 + PEA2 + (SCA+SMTE)2 + SD2 + SPE2 + STE2 + SPSE2 + M1MTE2 +
M2MTE2 + RTE2] 1/2 NON COTerror = [0.02 + 0.02 + (0.5+0.388)2 + 0.3752 + 0.02 + 1.9502 + 0.02 + 0.02 + 0.2002 + 0.52] 1/2 NON COTerror = + 2.241 % of span = + 0.672 PSIG COTerror = + (M12 + M22 + RD2) 1/2 COTerror = + (0.02 + 0.52 + 1.02) 1/2 COTerror = + 1.118 % of span = + 0.335 PSIG As Found Tolerance (AFT) = 3.6 PSIG + 0.335 PSIG As Left Tolerance (ALT) = 3.6 PSIG + 0.15 PSIG(1)
EE-0116 Page 175 of 205 Revision 7 See Figure 4.6.2 for specific details.
(1) ALT = + M2 = + 0.5 % of span = + (0.5 % / 100 %)
Analytical Limit (AL) 5 PSIG NON-COT ERRORS 0.672 PSIG TOTAL LOOP 0.763 PSIG UNCERTAINTY (TLU)
Allowable Value (AV) 4.328 PSIG COT ERRORS 0.091 PSIG Limiting Trip Setpoint (LTSP) 4.237 PSIG As Found Tolerance (AFT) 3.935 PSIG COT ERRORS SAFETY MARGIN 0.335 PSIG 0.637 PSIG Nominal Trip Setpoint (NTSP) 3.6 PSIG OPERATING MARGIN 1.6 PSIG High Operating Limit
< 2.0 PSIG (T.S. Section 3.6)
Nominal Operating Limit 0.0 PSIG Figure 4.6.2
EE-0116 Page 176 of 205 Revision 7 4.6.3 High - High Containment Pressure (Containment Spray)
As Found Tolerance: As Found Tolerance = 21.0 PSIG + 0.671 PSIG (Refs. 5.1, 5.90, 5.95, 5.110, and 5.111)
Subtracting the Total Loop Uncertainty (TLU) from the Analytical Limit (AL) yields a Limiting Trip Setpoint (LTSP) of 21.622 PSIG. Subtracting the NON COT error components from the Analytical Limit yields an Allowable Value (AV) of 21.827 PSIG. The current CTS Setting Limit for this function is < 23.0 PSIG. The CTS Setting Limit for this function of < 23.0 PSIG is set equal to the Analytical Limit and is non-conservative with respect to the Allowable Value. In addition, the current CTS Setting Limit is also non-conservative with respect to the calculated As Found Tolerance value of 21.0 PSIG +
0.671 PSIG (i.e., 21.671 PSIG). The Actual Nominal Trip Setpoint of 21.0 PSIG is conservative with respect to the Limiting Trip Setpoint. The CTS Setting Limit of < 23.0 PSIG will be changed to an As Found Tolerance value of 21.0 PSIG + 0.671 PSIG to conform to the requirements of TSFT-493, Rev. 4 and RIS 2006-17.
The statistical combination of the COT and NON COT error components from CSA Calculation C11006 (Ref. 5.95) are given below. The COT and NON COT error components are used in Figure 4.6.3 to determine the Limiting Trip Setpoint (LTSP) and the Allowable Value (AV).
NON COTerror = (PMA2 + PEA2 + (SCA+SMTE)2 + SD2 + SPE2 + STE2 + SPSE2 + M1MTE2 +
M2MTE2 + RTE2) 1/2 NON COTerror = [0.02 + 0.02 + (0.5+0.261)2 + 0.3752 + 0.02 + 1.6772 + 0.02 + 0.02 + 0.22 + 0.52) 1/2 NON COTerror = + 1.955 % of span = + 1.173 PSIG COTerror = + (M12 + M22 + RD2) 1/2 COTerror = + (0.02 + 0.52 + 1.02) 1/2 COTerror = + 1.118 % of span = + 0.671 PSIG As Found Tolerance (AFT) = 21.0 PSIG + 0.671 PSIG As Left Tolerance (ALT) = 21.0 PSIG + 0.300 PSIG(1)
See Figure 4.6.3 for specific details.
(1) ALT = + M2 = + 0.5 % of span = + (0.5 % / 100 %)
EE-0116 Page 177 of 205 Revision 7 KEWAUNEE'S HIGH HIGH CONTAINMENT PRESSURE CONTAINMENT SPRAY INITIATION Analytical Limit (AL) 23.0 PSIG NON-COT ERRORS 1.173 PSIG TOTAL LOOP 1.378 PSIG Allowable Value (AV)
UNCERTAINTY (TLU) 21.827 PSIG COT ERRORS 0.205 PSIG As Found Tolerance (AFT) 21.671 PSIG Limiting Trip Setpoint (LTSP) 21.622 PSIG COT ERRORS 0.671 PSIG SAFETY MARGIN 0.622 PSIG Nominal Trip Setpoint (NTSP) 21.00 PSIG OPERATING MARGIN 19.0 PSIG High Operating Limit
< 2.0 PSIG Nominal Operating Limit 0.0 PSIG Figure 4.6.3
EE-0116 Page 178 of 205 Revision 7 4.6.4 High - High Containment Pressure (Steam Line Isolation)
As Found Tolerance: As Found Tolerance = 15.0 PSIG + 0.671 PSIG (Refs. 5.1, 5.90, 5.95, 5.110, and 5.111)
Subtracting the Total Loop Uncertainty (TLU) from the Analytical Limit (AL) yields a Limiting Trip Setpoint (LTSP) of 15.622 PSIG. Subtracting the NON COT error components from the Analytical Limit yields an Allowable Value (AV) of 15.827 PSIG. The current CTS Setting Limit for this function is < 17.0 PSIG. The CTS Setting Limit for this function of < 17.0 PSIG is set equal to the Analytical Limit and is non-conservative with respect to the Allowable Value. In addition, the current CTS Setting Limit is also non-conservative with respect to the calculated As Found Tolerance value of 15.0 PSIG +
0.671 PSIG (i.e., 15.671 PSIG). The Actual Nominal Trip Setpoint of 15.0 PSIG is conservative with respect to the Limiting Trip Setpoint. The CTS Setting Limit of < 17.0 PSIG will be changed to an As Found Tolerance value of 15.0 PSIG + 0.671 PSIG to conform to the requirements of TSFT-493, Rev. 4 and RIS 2006-17.
The statistical combination of the COT and NON COT error components from CSA Calculation C11006 (Ref. 5.95) are given below. The COT and NON COT error components are used in Figure 4.6.4 to determine the Limiting Trip Setpoint (LTSP) and the Allowable Value (AV).
NON COTerror = (PMA2 + PEA2 + (SCA+SMTE)2 + SD2 + SPE2 + STE2 + SPSE2 + M1MTE2 +
M2MTE2 + RTE2) 1/2 NON COTerror = [0.02 + 0.02 + (0.5+0.261)2 + 0.3752 + 0.02 + 1.6772 + 0.02 + 0.02 + 0.22 + 0.52) 1/2 NON COTerror = + 1.955 % of span = + 1.173 PSIG COTerror = + (M12 + M22 + RD2) 1/2 COTerror = + (0.02 + 0.52 + 1.02) 1/2 COTerror = + 1.118 % of span = + 0.671 PSIG As Found Tolerance (AFT) = 15.0 PSIG + 0.671 PSIG As Left Tolerance (AFT) = 15.0 PSIG + 0.300 PSIG(1)
See Figure 4.6.4 for specific details.
(1) ALT = + M2 = + 0.5 % of span = + (0.5 % / 100 %)
EE-0116 Page 179 of 205 Revision 7 KEWAUNEE'S CONTAINMENT PRESSURE HI-HI STEAM LINE ISOLATION INITIATION Analytical Limit (AL) 17.0 PSIG NON-COT ERRORS 1.173 PSIG TOTAL LOOP 1.378 PSIG Allowable Value (AV)
UNCERTAINTY (TLU) 15.827 PSIG COT ERRORS 0.205 PSIG As Found Tolerance (AFT) 15.671 PSIG Limiting Trip Setpoint (LTSP) 15.622 PSIG COT ERRORS 0.671 PSIG SAFETY MARGIN 0.622 PSIG Nominal Trip Setpoint (NTSP) 15.00 PSIG OPERATING MARGIN 13.0 PSIG High Operating Limit
< 2.0 PSIG (T. S. Section 3.6)
Nominal Operating Setpoint 0.0 PSIG Figure 4.6.4
EE-0116 Page 180 of 205 Revision 7 4.6.5 Pressurizer Low Pressure (Safety Injection)
As Found Tolerance: 1830 PSIG + 10 PSIG (Refs. 5.1, 5.90, 5.93, and 5.105)
Adding the Total Loop Uncertainty (TLU) to the Analytical Limit (AL) yields a Limiting Trip Setpoint (LTSP) of 1755.62 PSIG. Adding the NON COT error components to the Analytical Limit yields an Allowable Value (AV) of 1754.94 PSIG. The Actual Nominal Trip Setpoint of 1830 PSIG is conservative with respect to the Limiting Trip Setpoint. The current Custom Technical Specification (CTS) Setting Limit value of > 1815 PSIG is conservative with respect to the Allowable Value. The current Custom Technical Specification (CTS) LSSS value > 1815 PSIG is non-conservative based on the calculated COT error components determined in Calculation C10818 (Ref. 5.93). The Setting Limit value of > 1815 PSIG will be changed to an As Found Tolerance value of 1830 PSIG + 10.0 PSIG to conform to the requirements of TSFT-493, Rev. 4 and RIS 2006-17. The revised As Found Tolerance value of > 1820 PSIG will allow a 10.00 PSIG margin to be used for the COT error components. The revised As Found Tolerance value of > 1820 PSIG is conservative with respect to the calculated Allowable Value but is non-conservative with respect to the calculated As Found Tolerance value using the CSA rack error terms from Calculation C10818 (Ref. 5.93).
The calculated As Found Tolerance value for this function is > 1821.06 PSIG based on using the COT error components. The 1.06 PSIG offset is accommodated in the 74.38 PSIG Safety Margin for this trip as illustrated in Figure 4.6.5.
The statistical combination of the COT and NON COT error components from CSA Calculation C10818 (Ref. 5.93) are given below. The COT and NON COT error components are used in Figure 4.6.5 to determine the Limiting Trip Setpoint (LTSP) and the Allowable Value (AV).
NON COTerror = SE + IR + [PMA2 + PEA2 + REDBE2 + SPTE2 + (SCA+SMTE)2 + SD2 + SPE2 + STE2
+ SPSE2 + M1MTE2 + M4MTE2 + RTE2]1/2 NON COTerror = 0.0 + 0.174 + [0.02 + 0.02 + 1.6882 + 8.02 + (0.250 + 0.391)2 + 0.752 + 0.02 + 2.3002 +
0.1582 + 0.02 + 0.22 + 0.52]1/2 NON COTerror = - 8.395 % or + 8.743 % of span = + 69.944 PSIG (worst case)
COTerror = + (M12 + M42 + RD2) 1/2 COTerror = + (0.0 + 0.52 + 1.02) 1/2 COTerror = + 1.118 % of span = + 8.944 PSIG (round to + 10 PSIG)
As Found Tolerance (AFT) = 1830 PSIG + 10 PSIG As Left Tolerance (ALT) = 1830 PSIG + 4.0 PSIG(1)
See Figure 4.6.5 for specific details.
(1) ALT = + M4 = + 0.5 % of span = + 4.0 PSIG
EE-0116 Page 181 of 205 Revision 7 KEWAUNEE'S PRESSURIZER LOW PRESSURE ESFAS INITIATION Nominal Operating Limit 2235 PSIG Low Operating Limit 2210 PSIG OPERATING MARGIN 380 PSIG Nominal Trip Setpoint (NTSP) 1830 PSIG COT ERRORS 10.0 PSIG SAFETY MARGIN As Found Tolerance (AFT) 74.38 PSIG (Static) 1820 PSIG Limiting Trip Setpoint (LTSP) 0.676 PSIG 1755.62 PSIG COT ERRORS TOTAL LOOP Allowable Value (AV) 1754.94 PSIG 70.62 PSIG NON-COT ERRORS UNCERTAINTY (TLU) 69.944 PSIG Analytical Limit (AL) 1685 PSIG Figure 4.6.5
EE-0116 Page 182 of 205 Revision 7 4.6.6 High Steam Flow Coincident with Safety Injection and Coincident with Tavg - Low Low As Found Tolerance: 0.75
- 106 lbs/hr + 0.149
- 106 lbs/hr (Refs. 5.1, 5.90, 5.98, 5.108, and 5.120)
Subtracting the Total Loop Uncertainty (TLU) from the Analytical Limit (AL) yields a Limiting Trip Setpoint (LTSP) of 0.944
- 106 lbs/hr. Subtracting the NON COT error components from the Analytical Limit yields an Allowable Value (AV) of 0.981
- 106 lbs/hr. The current CTS Setting Limit for this function is 0.745
- 106 lbs/hr. The CTS Setting Limit for this function of 0.745
- 106 lbs/hr is set conservative with respect to the Allowable Value. The current Nominal Trip Setpoint of 0.494
- 106 lbs/hr is conservative with respect to the Limiting Trip Setpoint, however it is set overly conservative and at an unstable flowrate during startup. The current Nominal Trip Setpoint will be changed to 0.75
- 106 lbs/hr equivalent to 19.63 % of Flownom(4). This revised Nominal Trip Setpoint will now be set at a more stable flowrate which should allow the trip to lock in without excessive relay chatter (i.e., passing through trip and reset multiple times) during the power escalation. The CTS Setting Limit of 0.745
- 106 lbs/hr will be changed to an As Found Tolerance Value of 0.75
- 106 lbs/hr + 0.149
- 106 lbs/hr to conform to the requirements of TSFT-493, Rev. 4 and RIS 2006-17. This As Found Tolerance Value of 0.75
- 106 lbs/hr + 0.149
- 106 lbs/hr is based on maintaining a Nominal Trip Setpoint value of 0.75
- 106 lbs/hr.
The statistical combination of the COT and NON COT error components from CSA Calculation C10854 (Ref. 5.98) are given below. Calculation C10854 is based on a Nominal Trip Setpoint of 0.494
- 106 lbs/hr versus the revised Nominal Trip Set point of 0.75
- 106 lbs/hr which allows the current Channel Statistical Allowance (CSA) value to be used in this analysis since it is conservative. The COT and NON COT error components are used in Figure 4.6.6 to determine the Limiting Trip Setpoint (LTSP) and the Allowable Value (AV).
NON COTerror = SE + [EA2 + PMA2 + PEA2 + (SCA+SMTE)2 + SD2 + SPE2 + STE2 + SPSE2 +
M1MTE2 + M2MTE2 + RTE2] 1/2 NON COTerror = 0.0 + [0.02 + 0.0662 + 3.3332 + (0.250+0.187)2 + 0.3862 + 0.5032 + 1.5572 + 0.1582 +
0.02 + 0.22 + 0.52]1/2 NON COTerror = + 3.801% of P span = + 17.197 % of Flow Span = + 0.769
- 106 lbs/hr(1)
COTerror = + (M12 + M22 + RD2)1/2 COTerror = + (0.02 + 0.52 + 1.02) 1/2 COTerror = + 1.118% of P span = + 3.332 % of Flow Span = + 0.149
- 106 lbs/hr(2)
As Found Tolerance (AFT) = 0.75
- 106 lbs/hr + 0.149
- 106 lbs/hr(2)
As Left Tolerance (ALT) = 0.75
- 106 lbs/hr + 0.067
- 106 lbs/hr(3)
See Figure 4.6.6 for specific details.
EE-0116 Page 183 of 205 Revision 7 KEWAUNEE'S HI STEAM FLOW COINCIDENT WITH SI AND LO-2 TAVG Analytical Limit (AL) 1.75
- 106 lbs/hr TOTAL LOOP NON-COT ERRORS 0.769
- 106 lbs/hr 0.806
- 10 6 lbs/hr UNCERTAINTY (TLU)
Allowable Value (AV) 0.981
- 106 lbs/hr 0.037
- 10 6 lbs/hr COT ERRORS Limiting Trip Setpoint (LTSP) 0.944
- 106 lbs/hr As Found Tolerance (AFT) 0.149
- 10 6 lbs/hr 0.899
- 106 lbs/hr SAFETY MARGIN COT ERRORS 0.194
- 106 lbs/hr Nominal Trip Setpoint (NTSP) 0.75
- 106 lbs/hr OPERATING MARGIN N/A(4)
High Operating Limit N/A(4)
Nominal Operating Limit N/A(4)
Figure 4.6.6 (1) The equation to convert % P error to % Flow error is: % flow span = (P uncertainty)
- 0.5 * (flow max / flow x) (Ref.
5.120). According to Reference 5.98, flow max = 4.47
- 106 lbs/hr and based on Reference 5.108, flow x = 0.494
- 106 lbs/hr. Therefore, the NON COTerror in terms of % Flow = + 3.801
- 0.5 * (4.47 / 0.494) = 17.197 % Flow span =
(17.197/100)
- 4.47 = + 0.769
- 106 lbs/hr.
(2) Using the information from Note 1 above and substituting the revised Nominal Trip Setpoint of 0.75* 106 lbs/hr , the AFT =
COTerror in terms of % Flow = + 1.118
- 0.5 * (4.47 / 0.75) = 3.332 % Flow span = (3.332/100)
- 4.47 = + 0.149
- 106 lbs/hr.
(3) The ALT = + M2 = + 0.5 % of P span. Using the information from Note 1 above and substituting the revised Nominal Trip Setpoint of 0.75* 106 lbs/hr, the ALT in terms of % Flow = + 0.5
- 0.5 * (4.47 / 0.75) = 1.49 % Flow span = (1.49/100)
- 4.47 = + 0.067
- 106 lbs/hr.
(4) The High Steam Flow portion of this ESFAS function is always active and will be locked in as a partial coincident trip at 0.75
- 106 lbs/hr, i.e., at 19.63 % Power where % power = (flow x / flow nom)
- 100 = (0.75 / 3.82)
- 100 = 19.63. Based on Reference 5.98, Flownom (nominal steam flow at 100 % power) = 3.82
- 106 lbs/hr.
EE-0116 Page 184 of 205 Revision 7 4.6.7 High High Steam Flow Coincident with Safety Injection As Found Tolerance: 4.3439
- 106 lbs/hr + 0.026
- 106 lbs/hr (Refs. 5.1, 5.90, 5.98, 5.108, and 5.120)
Subtracting the Total Loop Uncertainty (TLU) from the Analytical Limit (AL) yields a Limiting Trip Setpoint (LTSP) of 7.668
- 106 lbs/hr. Subtracting the NON COT error components from the Analytical Limit yields an Allowable Value (AV) of 7.673
- 106 lbs/hr. The current CTS Setting Limit for this function is 4.4
- 106 lbs/hr. The CTS Setting Limit for this function of 4.4
- 106 lbs/hr is set conservative with respect to the Allowable Value; however, the current CTS Setting Limit is set non-conservative with respect to the calculated As Found Tolerance value of 4.3439
- 106 lbs/hr + 0.026
- 106 lbs/hr (i.e., 4.3699
- 106 lbs/hr). The Actual Nominal Trip Setpoint of 4.3439
- 106 lbs/hr is conservative with respect to the Limiting Trip Setpoint. The CTS Setting Limit of 4.4
- 106 lbs/hr will be changed to an As Found Tolerance Value of 4.3439
- 106 lbs/hr + 0.026
- 106 lbs/hr to conform to the requirements of TSFT-493, Rev. 4 and RIS 2006-17. This As Found Tolerance Value of 4.3439
- 106 lbs/hr + 0.026
- 106 lbs/hr is based on maintaining a Nominal Trip Setpoint value of 4.3439
- 106 lbs/hr.
The statistical combination of the COT and NON COT error components from CSA Calculation C10854 (Ref. 5.98) are given below. The COT and NON COT error components are used in Figure 4.6.7 to determine the Limiting Trip Setpoint (LTSP) and the Allowable Value (AV).
NON COTerror = SE + [EA2 + PMA2 + PEA2 + (SCA+SMTE)2 + SD2 + SPE2 + STE2 + SPSE2 +
M1MTE2 + M2MTE2 + RTE2] 1/2 NON COTerror = 0.0 + [0.02 + 0.02 + 3.3332 + (0.250+0.187)2 + 0.3862 + 0.5032 + 1.5572 + 0.1582 + 0.02
+ 0.22 + 0.52]1/2 NON COTerror = + 3.800% of P span = + 1.955 % of Flow Span = + 0.087
- 106 lbs/hr(1)
COTerror = + (M12 + M22 + RD2)1/2 COTerror = + (0.02 + 0.52 + 1.02) 1/2 COTerror = + 1.118% of P span = + 0.575 % of Flow Span = + 0.026
- 106 lbs/hr(2)
As Found Tolerance (AFT) = 4.3439
- 106 lbs/hr + 0.026
- 106 lbs/hr(2)
As Left Tolerance (ALT) = 4.3439
- 106 lbs/hr + 0.011
- 106 lbs/hr(3)
See Figure 4.6.7 for specific details.
EE-0116 Page 185 of 205 Revision 7 KEWAUNEE'S HI HI STEAM FLOW COINCIDENT WITH SAFETY INJECTION Analytical Limit (AL) 7.76
- 106 lbs/hr TOTAL LOOP NON-COT ERRORS 0.087
- 106 lbs/hr 0.092
- 106 lbs/hr UNCERTAINTY (TLU)
Allowable Value (AV) 7.673
- 106 lbs/hr COT ERRORS 0.005
- 106 lbs/hr Limiting Trip Setpoint (LTSP) 7.668
- 106 lbs/hr As Found Tolerance (AFT) 4.3699
- 106 lbs/hr 0.026
- 106 lbs/hr COT ERRORS SAFETY MARGIN 3.324
- 106 lbs/hr Nominal Trip Setpoint (NTSP) 4.3439
- 106 lbs/hr OPERATING MARGIN 0.448
- 106 lbs/hr High Operating Limit 3.896
- 106 lbs/hr (approx. 102 % Power)
Nominal Operating Limit 3.82
- 106 lbs/hr (flow nom)
Figure 4.6.7 (1) The equation to convert % P error to % Flow error is: % flow span = (P uncertainty)
- 0.5 * (flow max / flow x) (Ref.
5.120). According to Reference 5.98, flow max = 4.47
- 106 lbs/hr and based on Reference 5.108, flow x = 4.3439
- 106 lbs/hr. Therefore, the NON COTerror in terms of % Flow = + 3.800
- 0.5 * (4.47 / 4.3439) = 1.955 % Flow span =
(1.955/100)
- 4.47 = + 0.087
- 106 lbs/hr.
(2) Using the information from Note 1 above, the AFT = COTerror in terms of % Flow = + 1.118
- 0.5 * (4.47 / 4.3439) = 0.575
% Flow span = (0.575/100)
- 4.47 = + 0.026
- 106 lbs/hr.
(3) The ALT = + M2 = + 0.5 % of P span. Using the information from Note 1 above, the ALT in terms of % Flow = + 0.5
- 0.5 * (4.47 / 4.3439) = 0.257 % Flow span = (0.257/100)
- 4.47 = + 0.011
- 106 lbs/hr.
EE-0116 Page 186 of 205 Revision 7 4.6.8 Low-Low TAVG Coincidence input to Steam Line Isolation As Found Tolerance Value: 541.0 oF + 1.38 oF (Refs. 5.1, 5.90, 5.94, and 5.105)
The current Custom Technical Specification (CTS) Setting Limit for this function is > 540.0 oF. The current Nominal Trip Setpoint for this function is > 541.0 oF (Ref. 5.105). The Low TAVG Coincidence input to the Steam Line Isolation ESFAS function is not credited in the Kewaunee USAR Chapter 14 Safety Analysis (Ref. 5.1); however a Channel Statistical Allowance (CSA) Calculation has been performed for this function. Based on Calculation C11865 (Ref. 5.94), the COT error allowance for this function is + 1.38 % of span = + 1.38 oF. The As Found Tolerance based on the COT error from Calculation C11865 is 541 oF + 1.38 oF. The CTS Setting Limit for this function of > 540.0 oF is set slightly conservative with respect to the calculated As Found Tolerance value of 541 oF + 1.38 oF (i.e.
539.62 oF). The As Found Tolerance being slightly non-conservative with respect to the current CTS Setting Limit is acceptable because there is no Analytical Limit associated with this function. The As Left Tolerance will be based on the COT error allowance minus Rack Drift (i.e., RD2 from Ref. 5.94).
The As Found and As Left Tolerances are based on maintaining a Nominal Trip Setpoint Value of 541 o
F.
As Found Tolerance (AFT) = 541.0 oF + 1.38 oF(1)
As Left Tolerance (ALT) = 541 oF + 0.95 oF (2)
(1) AFT = + ((M1
- 0.667)2 + (M2
- 0.667)2 + M42 + M82 + RD22) 1/2 = +((0.417
- 0.667)2 + (0.417
- 0.667)2 + 0.7072 + 0.52 +
1.02) 1/2 = + 1.38 % of TAVG span (2) (2) ALT = + ((M1
- 0.667)2 + (M2
- 0.667)2 + M42 + M82) 1/2 = + ((0.417
- 0.667)2 + (0.417
- 0.667)2 + 0.7072 + 0.52) 1/2 =
+ 0.95 % of TAVG span (3) The effective gain of the TAVG summing junction is set by the relationship of the TAVG span versus the span of THOT and TCOLD (i.e., 520 to 620 oF versus 500 to 650 oF, span equal to 150 oF). For Kewaunee, the effective gain is 0.6667 V/V, therefore
% TAVG span is equal to % THOT span or TCOLD span
- 0.6667.
4.6.9 Steam Line Pressure - Low As Found Tolerance: 514.0 PSIG + 17.15 PSIG (Refs. 5.1, 5.90, 5.98, and 5.108)
Adding the Total Loop Uncertainty (TLU) to the Analytical Limit (AL) yields a Limiting Trip Setpoint (LTSP) of 511.066 PSIG. Adding the NON COT error components to the Analytical Limit yields an Allowable Value (AV) of 504.01 PSIG. The Actual Nominal Trip Setpoint of 514.0 PSIG is conservative with respect to the Limiting Trip Setpoint. The current Custom Technical Specifications (CTS) Setting Limit of > 500 PSIG is non-conservative with respect to the calculated Allowable Value and is conservative with respect to the calculated As Found Tolerance. The As Found Tolerance of 514 PSIG + 17.15 PSIG is based on the calculated COT error allowance from Calculation C10854 (Ref.
5.98). The Custom Technical Specifications (CTS) Setting Limit of > 500 PSIG will be changed to an As Found Tolerance of 514 PSIG + 17.15 PSIG to conform to the requirements of TSFT-493, Rev. 4 and RIS 2006-17. The calculated As Left Tolerance will be based on the COT error allowance from Calculation C10854 minus Rack Drift (RD). The As Found and As Left Tolerances are based on maintaining a Nominal Trip Setpoint of 514.0 PSIG.
EE-0116 Page 187 of 205 Revision 7 The statistical combination of the COT and NON COT error components from CSA Calculation C10854 (Ref. 5.98) are given below. The COT and NON COT error components are used in Figure 4.6.9 to determine the Limiting Trip Setpoint (LTSP) and the Allowable Value (AV).
NON COTerror = SE + [EA2 + PMA2 + PEA2 + (SCA+SMTE)2 + SD2 + SPE2 + STE2 + SPSE2 +
M1MTE2 + M2MTE2 + M3MTE2 + RTE2]1/2 NON COTerror = 0.0 + [0.02 + 0.02 + 0.02 + (0.250 + 0.180)2 + 0.4292 + 0.02 + 1.4752 + 0.1582 + 0.02 +
0.2832 + 0.22 + 0.52 ]1/2 NON COTerror = + 1.715 % of span = + 24.01 PSIG COTerror = + (M12 +M22 + M32 + RD2) 1/2 COTerror = + (0.02 + 0.52 + 0.52 + 1.02) 1/2 COTerror = + 1.225 % of span = + 17.15 PSIG As Found Tolerance (AFT) = 514.0 PSIG + 17.15 PSIG As Left Tolerance (ALT) = 514 PSIG + 10.0 PSIG(1)
See Figure 4.6.9 for specific details.
(1) ALT = (M12 +M22 + M32 ) 1/2 = + (0.02 + 0.52 + 0.52) 1/2 = + 0.707 % of span = + 9.898 PSIG (round to + 10. PSIG)
EE-0116 Page 188 of 205 Revision 7 KEWAUNEE'S STEAM LINE PRESSURE LOW ESFAS INITIATION Nominal Operating Limit 790.0 PSIG Low Operating Limit 600.0 PSIG (Low Press Alarm STPT)
OPERATING MARGIN 86 PSIG (Static)
Nominal Trip Setpoint (NTSP) 514.0 PSIG COT ERRORS 17.15 PSIG SAFETY MARGIN 2.934 PSIG (Static)
As Found Tolerance (AFT) 496.85 PSIG Limiting Trip Setpoint (LTSP) 511.066 PSIG COT ERRORS 7.056 PSIG TOTAL LOOP 31.066 PSIG Allowable Value (AV) 504.01 PSIG UNCERTAINTY (TLU)
NON-COT ERRORS 24.01 PSIG Analytical Limit (AL) 480.0 PSIG Figure 4.6.9
EE-0116 Page 189 of 205 Revision 7 4.6.10 Steam Generator Water Level Low Low Reactor Trip / Auxiliary Feedwater Initiation See item 4.5.15.
4.6.11 SG Water Level - High High See Section 3.5.3.
EE-0116 Page 190 of 205 Revision 7 4.7 Limiting Trip Setpoints, Allowable Values, As Found Tolerances, and As Left Tolerances for Kewaunee Instrumentation associated with LCOs 3.3.5, 3.3.6, and 3.3.7 to support the Setpoint Control Program 4.7.1 Safeguards Bus Undervoltage (Loss of Voltage)
As Found Tolerance: 84.47 + 0.200 % of Bus Voltage = 101.69 + 0.241 VAC with a time delay of 1.75 seconds + 0.25 seconds (Refs. 5.1, 5.90, 5.102, & 5.129)
The current Custom Technical Specification (CTS) Setting Limit for this function is 85 % + 2 % of bus voltage in < 2.5 secs. The current Nominal Trip Setpoint for this function is 101.49 to 101.89 VAC where 101.69 VAC is the centerline voltage = 84.47 % of bus voltage(1) (Ref. 5.102 & 5.129). This analysis assumes that 120.39 VAC from the potential transformer is equal to 100 % of bus voltage which is equal to 4160 VAC per the conversion factor as noted in footnote 1. The Safeguards Bus Undervoltage Loss of Power Trip is not credited in the Kewaunee USAR Chapter 14 Safety Analysis (Ref. 5.1); however a Channel Statistical Allowance (CSA) calculation has been performed for this function. The calibration accuracy for this trip is 101.69 + 0.2 VAC = 84.47 + 0.166 % of bus voltage (1)
(Ref. 5.129). The COT error from Calculation C11709 is + 0.200 % of bus voltage = + 0.241 VAC.
Therefore, the As Found Tolerance for the Safeguards Bus Undervoltage Loss of Power Trip is 84.47 +
0.200 % of bus voltage = 101.69 + 0.241 VAC(1) based on the device calibration accuracy from Reference 5.102. The As Left Tolerance for the Safeguards Bus Undervoltage Loss of Power Trip is 84.47 + 0.166 % of bus voltage = 101.69 + 0.200 VAC based on the device calibration accuracy from Reference 5.129. The As Found Tolerance and As Left Tolerance are based on maintaining a Nominal Trip Setpoint Value of 101.69 VAC = 84.47 % of bus voltage.
The time delay associated with this trip is based on a setpoint of 1.75 seconds + 0.01 seconds (Ref.
5.129). Calculation C11709 (Ref. 5.102) gives a total error associated with the relays as 14.14 % of the settings. Utilizing the total error of 14.14 % of the setting provides a range of 1.50 seconds to 2.00 seconds based on a setpoint of 1.75 seconds. Therefore, the Time Delay As Found Tolerance is 1.75 seconds + 0.25 seconds. The Time Delay As Left Tolerance is 1.75 + 0.10(5) second based on the device calibration accuracy from Reference 5.129.
As Found Tolerance (AFT) = 84.47 + 0.200 % of bus voltage = 101.69 + 0.241 VAC(2)
As Left Tolerance (ALT) = 84.47 + 0.166 % of bus voltage = 101.69 + 0.200 VAC(3)
Time Delay As Found Tolerance = 1.75 Seconds + 0.25 seconds Time Delay As Left Tolerance = 1.75 Seconds + 0.10 seconds(5)
As Found Tolerance (AFT) = 84.15 + 0.200 % of bus voltage = 101.31 + 0.241 VAC(4)
As Left Tolerance (ALT) = 84.15 + 0.166 % of bus voltage = 101.31 + 0.200 VAC(4)
(1) Convert % bus Voltage to VAC as follows:
4160*(% bus Volts / 100) / (sqrt (3)
- 20
- 0.9975) = VAC Where 20 is the PT turn down ratio and 0.9775 is the Ratio Correction Factor (Ref. 5.102).
(2) AFT = + SCA = + 0.200 % bus voltage (From Reference 5.102).
(3) ALT = Current Calibration Accuracy from Reference 5.129 = + 0.166 % bus voltage.
(4) Calculation C11709 (Ref. 5.102) recommends a setpoint change for the Safeguards Bus Undervoltage Loss of Voltage Trip. The recommended setpoint will be 101.31 + 0.200 VAC = 84.15 + 0.166 % of bus voltage for the relay Dropout.
EE-0116 Page 191 of 205 Revision 7 The COT error from Calculation C11709 is + 0.200 % of bus voltage = + 0.241 VAC. Therefore, the As Found Tolerance for the Safeguards Bus Undervoltage Loss of Power Trip is 84.15 + 0.200 % of bus voltage = 101.31 + 0.241 VAC based on the device calibration accuracy from Reference 5.102. The As Left Tolerance for the Safeguards Bus Undervoltage Loss of Power Trip is 84.15 + 0.166 % of bus voltage = 101.31 + 0.200 VAC based on the recommendation from Reference 5.102. The As Found Tolerance and As Left Tolerance are based on implementing the recommendations of Calculation C11709 and setting the Nominal Trip Setpoint to a value of 101.31 VAC = 84.15 % of bus voltage. The same Time Delay Tolerances apply for the new setpoints.
(5) Undervoltage relays 27A/B5, 27C/B5, 26A/B6, 27C/B6 have an As Left time delay of 0.01 seconds listed in the Electrical Preventive Maintenance Procedures with an As Found time delay of 0.1 seconds. The procedure value of 0.01 seconds is conservative to the As Left Tolerance of 0.1 seconds as described above.
4.7.2 Safeguards Bus Second Level Undervoltage (Degraded Voltage)
As Found Tolerance: 93.80 + 0.179 % of bus voltage = 112.93 + 0.215 VAC with a time delay of 6.72 seconds + 0.68 seconds (Refs. 5.1, 5.90, 5.102, & 5.129)
The current Custom Technical Specification (CTS) Setting Limit for this function is 93.6 % + 0.9 % of bus voltage in < 7.4 secs. The current Nominal Trip Setpoint for this function is 112.73 to 113.13 VAC where 112.93 VAC is the centerline voltage = 93.80 % of bus voltage(1) (Ref. 5.102 & 5.129). This analysis assumes that 120.39 VAC from the potential transformer is equal to 100 % of bus voltage which is equal to 4160 VAC per the conversion factor as noted in footnote 1. The Safeguards Bus Second Level Undervoltage Degraded Voltage Trip is not credited in the Kewaunee USAR Chapter 14 Safety Analysis (Ref. 5.1); however a Channel Statistical Allowance (CSA) calculation has been performed for this function. The calibration accuracy for this trip is 112.93 + 0.2 VAC = 93.80 + 0.166
% of bus voltage (1) (Ref. 5.129). The COT error from Calculation C11709 is + 0.179 % of bus voltage =
+ 0.215 VAC. Therefore, the As Found Tolerance for the Safeguards Bus Second Level Undervoltage Degraded Voltage Trip is 93.80 + 0.179 % of bus voltage = 112.93 + 0.215 VAC based on the device calibration accuracy from Reference 5.102. The As Left Tolerance for the Safeguards Bus Second Level Undervoltage Degraded Voltage Trip is 93.80 + 0.166 % of bus voltage = 112.93 + 0.200 VAC based on the device calibration accuracy from Reference 5.129. The As Found Tolerance and As Left Tolerance are based on maintaining a Nominal Trip Setpoint Value of 112.93 VAC = 93.80 % of bus voltage.
The time delay associated with this trip is based on a setpoint of 6.72 seconds + 0.01 seconds (Ref.
5.129). Calculation C11709 (Ref. 5.102) gives a total error associated with the relays as 10.1 % of the settings. Utilizing the total error of 10.1 % of the setting provides a range of 6.04 seconds to 7.40 seconds based on a setpoint of 6.72 seconds. Therefore, the Time Delay As Found Tolerance is 6.72 seconds + 0.68 seconds. The Time Delay As Left Tolerance is 6.72 + 0.10(5) second based on the device calibration accuracy from Reference 5.129.
As Found Tolerance (AFT) = 93.80 + 0.179 % of bus voltage = 112.93 + 0.215 VAC(2)
As Left Tolerance (ALT) = 93.80 + 0.166 % of bus voltage = 112.93 + 0.200 VAC (3)
Time Delay As Found Tolerance = 6.72 Seconds + 0.68 seconds Time Delay As Left Tolerance = 6.72 Seconds + 0.10 seconds(5)
As Found Tolerance (AFT) = 93.50 + 0.200 % of bus voltage = 112.57 + 0.215 VAC(4)
As Left Tolerance (ALT) = 93.50 + 0.166 % of bus voltage = 112.57 + 0.200 VAC(4)
EE-0116 Page 192 of 205 Revision 7 (1) Convert % bus Voltage to VAC as follows:
4160*(% bus Volts / 100) / (sqrt (3)
- 20
- 0.9975) = VAC Where 20 is the PT turn down ratio and 0.9775 is the Ratio Correction Factor (Ref. 5.102).
(2) AFT = + SCA = + 0.179 % bus voltage (From Reference 5.102).
(3) ALT = Current Calibration Accuracy from Reference 5.129 = + 0.166 % bus voltage.
(4) Calculation C11709 (Ref. 5.102) recommends a setpoint change for the Safeguards Bus Undervoltage Degraded Voltage Trip. The recommended setpoint will be 112.57 + 0.200 VAC = 93.50 + 0.166 % of bus voltage for the relay Dropout.
The COT error from Calculation C11709 is + 0.179 % of bus voltage = + 0.215 VAC. Therefore, the As Found Tolerance for the Safeguards Bus Undervoltage Degraded Voltage Trip is 93.50 + 0.179 % of bus voltage = 112.57 +
0.215 VAC based on the device calibration accuracy from Reference 5.102. The As Left Tolerance for the Safeguards Bus Undervoltage Degraded Voltage Trip is 93.50 + 0.166 % of bus voltage = 112.57 + 0.200 VAC based on the recommendation from Reference 5.102. The As Found Tolerance and As Left Tolerance are based on implementing the recommendations of Calculation C11709 and setting the Nominal Trip Setpoint to a value of 112.57 VAC = 93.50 % of bus voltage. The same Time Delay Tolerances apply for the new setpoints.
(5) Undervoltage (Degraded Voltage) relays 27AY/B5, 27CY/B5, 26AY/B6, 27CY/B6 have an As Left time delay of 0.01 seconds listed in the Electrical Preventive Maintenance Procedures with an As Found time delay of 0.1 seconds. The procedure value of 0.01 seconds is conservative to the As Left Tolerance of 0.1 seconds as described above.
4.7.3 Forebay Level As Found Tolerance: 162 H2O + 9 H2O (Refs. 5.1, 5.90, 5.101 & 5.121)
The current Custom Technical Specifications (CTS) do not list a Setting Limit value associated with the Forebay Level Trip. The Forebay Level Trip function is not credited in the Kewaunee USAR Chapter 14 Safety Analysis (Ref. 5.1). The current As Found Nominal Trip Setpoint for this function is 162 Inches H2O Decreasing + 9.0 Inches H2O per Reference 5.121. The current As Left Nominal Trip Setpoint is 162 Inches H2O Decreasing + 4.5 Inches H2O per Reference 5.121. Per Calculation C11220 (Ref.
5.101) testing concluded that at a water level of 565 3, acceptable conditions exist for continued operation of the SW pumps. The setpoint of 162 H2O is equivalent to 566 Forebay water level per Reference 5.101, which yields a difference of 9 H2O to be used for the As Found Tolerance.
As Found Tolerance (AFT) = 162 H2O + 9 H2O(1)
As Left Tolerance (ALT) = 162 H2O + 4.5 H2O(2)
(1) AFT = Margin from minimum level for SW Pump operation - Existing Setpoint Equivalent (Ref. 5.101) = 566 - 5653
= 9 (2) ALT = Current As Left Calibration Accuracy from Reference 5.121 = 4.5
EE-0116 Page 193 of 205 Revision 7 4.7.4 Containment Purge and Vent System Radiation Particulate Detector and Radioactive Gas Detector Containment Ventilation Isolation Containment Gas Radiation Monitors (R12 and R21)
As Found Tolerance: 2.2 E+05 CPM + BKG (Refs. 5.1, 5.90, 5.113, 5.114, 5.115, 5.123, 5.124, 5.131, & 5.143)
The current Custom Technical Specifications (CTS) Setting Limit for this function states < radiation levels in exhaust duct as defined in footnote(3). The current Nominal Trip Setpoint (4) for the Containment Gas Radiation Monitors are 8.00 E +04 CPM for the High Alarm Setpoint per References 5.123 and 5.143. The Containment Gas Radiation monitors are not credited in the Chapter 14 Safety Analysis (Ref. 5.1). The Alert and Alarm setpoints are determined IAW the methodology outlined in the Kewaunee Power Station Offsite Dose Calculation Manual (ODCM) and documented in Calculation C10690 (Ref. 5.115). The High Alarm Setpoint provides the Containment Isolation signal. The calculated High Alarm Setpoint per the ODCM and Calculation C10690 (Refs. 5.113 & 5.115) is currently 2.2 E +05 CPM + Background (BKG). The Setpoints listed in Reference 5.123 are set conservative to the values determined in the ODCM and Calculation C10690 (Refs. 5.113 & 5.115).
There are currently no Analytical Limits or Allowable Values associated with this function (Ref. 5.1).
The determination of the setpoints is not within the scope of the Setpoint Control Program and the current High Alarm Nominal Trip Setting of 8.00E +04 CPM is conservative with respect to the calculated value listed in the ODCM and Calculation C10690. Based on Reference 5.113 & 5.115 the As Found Tolerance will be 2.2 E +05 CPM + Background. The As Left Tolerance will be based on the existing High Alarm Setpoint listed in Reference 5.123.
As Found Tolerance (AFT) = 2.2 E+05 CPM + BKG (1)
As Left Tolerance (ALT) = 8.00 E+04 CPM (2)
(1) AFT = Setpoint taken from Reference 5.113 & 5.115 (2) ALT = Calibration Procedure Setpoint = 8.0 E+04 CPM ( Reference 5.123 & 5.124)
(3) Footnote three from Technical Specification Table 3.5-1 page 2 of 2 states The setting limits for max radiation levels are derived from ODCM Specification 3.4.1 and Table 2.2, and USAR Section 6.5.
(4) The Alert Setpoint is determined IAW References 5.113 and 5.115 and is set at 2.00 E +04 CPM per Reference 5.123.
The Alert Setpoint provides an alarm function only and the Containment Isolation signal is provided by the High Alarm Setpoint.
EE-0116 Page 194 of 205 Revision 7 4.7.5 Containment Particulate Radiation Monitor (R11)
As Found Tolerance: 8.00 E+04 CPM (Refs. 5.1, 5.90, 5.113, 5.114, 5.115, 5.122, 5.124, & 5.131)
The current Custom Technical Specifications (CTS) Setting Limit for this function states < radiation levels in exhaust duct as defined in footnote(3). The current Nominal Trip Setpoint for the Containment Particulate Radiation Monitor is 5.00 E +04 CPM for the alert setpoint and 8.00 E +04 CPM for the High Alarm per Reference 5.122. The Containment Particulate Radiation monitor is not credited in the Chapter 14 Safety Analysis (Ref. 5.1). Per USAR Table 11.2.7 the Setpoint is set Statistically significant level above background. The Design Change Process which is controlled by the 50.59/72.48 process is utilized to determine any setpoint changes associated with the Containment Particulate Radiation Monitors. The existing setpoints are shown on drawing E-2021 (Ref. 5.124) and were derived utilizing this process and will be maintained as the As Found Tolerance and the As Left Tolerance.
As Found Tolerance (AFT) = 8.00 E+04 CPM (1)
As Left Tolerance (ALT) = 8.00 E+04 CPM (2)
(1) AFT = Calibration Procedure Setpoint = 8.0 E+04 CPM ( Reference 5.122, & 5.124)
(2) ALT = Calibration Procedure Setpoint = 8.0 E+04 CPM ( Reference 5.122 & 5.124)
(3) Footnote three from Technical Specification Table 3.5-1 page 2 of 2 states The setting limits for max radiation levels are derived from ODCM Specification 3.4.1 and Table 2.2, and USAR Section 6.5.
4.7.6 Control Room Ventilation Radiation Monitor (R23)
As Found Tolerance: 1.00 E+04 CPM (Refs. 5.1, 5.114, 5.124, & 5.125)
The current Custom Technical Specifications (CTS) Setting Limit does not specify a Setting Limit for this Radiation Monitor. The Improved Technical Specifications have added this monitor. The current Nominal Trip Setpoint for the Control Room Ventilation Radiation Monitor is 5.00 E +03 CPM for the alert setpoint and 1.00 E +04 CPM for the High Alarm per References 5.124 and 5.125. The Control Room Ventilation Radiation Monitor is not credited in the Chapter 14 Safety Analysis (Ref. 5.1). Per USAR Table 11.2.7 the Setpoint is set Statistically significant level above background. The Design Change Process which is controlled by the 50.59/72.48 process is utilized to determine any setpoint changes associated with the Control Room Radiation Monitor. The existing setpoints are shown in drawing E-2021 (Ref. 5.124) and were derived utilizing this process and will be maintained as the As Found Tolerance and the As Left Tolerance.
As Found Tolerance (AFT) = 1.00 E+04 CPM (1)
As Left Tolerance (ALT) = 1.00 E+04 CPM (2)
(3) AFT = Calibration Procedure Setpoint = 1.0 E+04 CPM ( Reference 5.124, & 5.125)
(4) ALT = Calibration Procedure Setpoint = 1.0 E+04 CPM ( Reference 5.124, & 5.125)
EE-0116 Page 195 of 205 Revision 7 4.7.7 Turbine Building Service Water Header Isolation As Found Tolerance: 82.5 PSIG + 1.0 PSIG (Refs. 5.1, 5.114, 5.140, & 5.141)
The current Custom Technical Specifications (CTS) does not address the Turbine Building Service Water Header Isolation function. Improved Technical Specifications (ITS) has added this function to ITS Table 3.3.2-1. Based on References 5.140 and 5.141, the current Nominal Trip Setpoint for Turbine Building Service Water Low Pressure Isolation is 82.5 PSIG (decreasing). The Turbine Building Service Water Header Isolation function is not credited in the Chapter 14 Safety Analysis (Ref. 5.1).
Based on Reference 5.140, the calibration accuracy for the pressure switch is + 1.0 PSIG. For this application, the As Found Tolerance and As Left Tolerance will be set at the same value, i.e., + 1.0 PSIG.
As Found Tolerance (AFT) = 82.5 PSIG + 1.0 PSIG As Left Tolerance (ALT) = 82.5 PSIG + 1.0 PSIG (5) AFT = Calibration Procedure Setpoint = + 1.0 PSIG ( Reference 5.140)
(6) ALT = Calibration Procedure Setpoint = + 1.0 PSIG ( Reference 5.140)
EE-0116 Page 196 of 205 Revision 7
5.0 REFERENCES
5.1 Technical Report NE-0994, Revision 17, Safety Analysis Limits for Technical Specification Instrumentation - Companion to EE-0101, September 2009.
5.2 Technical Report EE-0101, Revision 10, Setpoint Basis Document - Analytical Limits, Setpoints and Calculations for Technical Specification Instrumentation At North Anna and Surry Power Stations, Dated 12-11-07.
5.3 Westinghouse - NAPS Reactor Protection System/Engineered Safety Features Actuation System Setpoint Methodology (NRC Letter - S/N 541, Dated 09-28-78).
5.4 Engineering Transmittal CEE 99-0028, Revision 0, Response to Open Items ITS LCO 3.3.1, Surry Power Station Units 1 and 2, Dated 10-29-99.
5.5 Dominion Virginia Power STD-EEN-0304, Revision 6, Calculating Instrumentation Uncertainties By the Square Root of the Sum of the Squares Method.
5.6 Dominion Virginia Power STD-GN-0030, Revision 8, Nuclear Plant Setpoints.
5.7 Surry Power Station Technical Specifications.
5.8 North Anna Power Station Technical Specifications.
5.9 USNRC Regulatory Guide 1.105, Revision 3 (December 1999), Setpoints for Safety-Related Instrumentation.
5.10 Improved Thermal Design Procedure, Instrument Uncertainties for North Anna Units 1 & 2 Core Uprating C. R. Tuley July 1986, Westinghouse Electric Corporation.
5.11 Dominion Virginia Power Technical Report EE-0099, Revision 0 (AR), North Anna Instrument Tolerance Document.
5.12 Dominion Virginia Power Technical Report EE-0100, Revision 2 with Appendices 5, 12, and 18.
5.13 Dominion Virginia Power Technical Report EE-0085, Revision 2 with Appendices 5, 12, and 18.
5.14 Engineering Transmittal CEE 95-037, Revision 2, Transmittal of Surveillance Limits for RPS and ESFAS Primary Trip Functions at Surry Power Station Units 1 and 2, Dated 03-20-02.
5.15 Dominion Virginia Power Calculation EE-0063, Revision 2, Setpoint Accuracy for Power Range Neutron Flux High Setpoint Reactor Trip, North Anna Power Station, Units 1 and 2.
5.16 Dominion Virginia Power Calculation EE-0738, Revision 1, Add. 00A, NIS Intermediate Range Channel Statistical Allowance Calculation.
EE-0116 Page 197 of 205 Revision 7 5.17 Dominion Virginia Power Calculation EE-0710, Revision 0, North Anna Nuclear Instrumentation Source Range Uncertainty.
5.18 Dominion Virginia Power Calculation EE-0434, Revision 2, Delta T and T AVG Protection Loops, T-412, T-422 and T-432, North Anna Power Station, Units 1 and 2.
5.19 Dominion Virginia Power Calculation EE-0069, Revision 3, with Add 00A, Setpoint and Indication Accuracy for Pressurizer Pressure Loops.
5.20 Dominion Virginia Power Calculation EE-0058, Revision 2, CSA for North Anna Pressurizer Level Protection & Indication CSA.
5.21 Dominion Virginia Power Calculation EE-0060, Revision 3, CSA for North Anna Power Station Units 1 &
2 Reactor Coolant Flow Protection.
5.22 Dominion Virginia Power Calculation EE-0492, Revision 2, with Add. 00A, CSA Calculation for North Anna Power Station, Steam Generator Narrow Range Level, Units 1 & 2, Loops L-1474, L-1475, L-1476, L-1484, L-1485, L-1486, L-1494, L-1495, L-1496, L-2474, L-2475, L-2476, L-2484, L-2485, L-2486, L-2494, L-2495, & L-2496.
5.23 Dominion Virginia Power Calculation EE-0736, Revision 5, Channel Uncertainty for North Anna Units 1&2 Feedwater Flow and Steam Flow Channels Including Channel Check Criteria for Feedwater and Steam Flow Indication.
5.24 Dominion Virginia Power Calculation EE-0524, Revision 0 with Add. 0A and 0B, Reactor Coolant Pump Undervoltage and Underfrequency Trip Setpoints.
5.25 Dominion Virginia Power Calculation EE-0052, Revision 2, with Add. 00A, North Anna Containment Narrow Range Pressure Uncertainty.
5.26 Dominion Virginia Power Calculation EE-0121, Revision 3, with Add. 00A North Anna Main Steam Pressure Protection Channel Uncertainty.
5.27 Dominion Virginia Power Calculation EE-0092, Revision 4, North Anna Refueling Water Storage Tank Level Uncertainty - Wide Range.
5.28 Dominion Virginia Power Calculation EE-0198, Revision 1 with Add. 1A, Setpoint Accuracy for Power Range Neutron Flux High Setpoint Reactor Trip.
5.29 Dominion Virginia Power Calculation EE-0722, Revision 1, NIS Intermediate Range Channel Statistical Allowance Calculation.
5.30 Dominion Virginia Power Calculation EE-0719, Revision 0, Surry Nuclear Instrumentation Source Range Uncertainty.
EE-0116 Page 198 of 205 Revision 7 5.31 Dominion Virginia Power Calculation EE-0415, Revision 2, Delta T and T Average Protection Loops, T-412, T-422 and T-432, Surry Power Station, Units 1 and 2.
5.32 Dominion Virginia Power Calculation EE-0514, Revision 1, Pressurizer Pressure Protection and Indication Uncertainties CSA.
5.33 Dominion Virginia Power Calculation EE-0458, Revision 1, with Add. 00A and 00B, Channel Statistical Allowance (CSA) Calculation for Surry Pressurizer Level Protection, Surry Units 1 and 2.
5.34 Dominion Virginia Power Calculation EE-0183, Revision 3, with Add. 00A, CSA Calculation for Surry Power Station Units 1 and 2 Reactor Coolant Flow.
5.35 Dominion Virginia Power Calculation EE-0432, Revision 4 with Add. 00A, CSA Calculation for Surry Power Station, Steam Generator Narrow Range Level, Units 1&2, Loops L-1474, L-1475, L-1476, L-1484, L-1485, L-1486, L-1494, L-1495, L-1496, L-2474, L-2475, L-2476, L-2484, L-2485, L-2486, L-2494, L-2495, L-2496.
5.36 Dominion Virginia Power Calculation EE-0355, Revision 3, with Add. 03A, 00B, 00C, and 00D, Channel Uncertainty Calculation for Surry, Units 1&2 Feedwater Flow, Steam Flow, Steam Pressure and Steam Header Pressure Protection and Control Including Channel Check Criteria for Feedwater and Steam Flow Indication.
5.37 Dominion Virginia Power Calculation EE-0412, Revision 0, with Add. 0A and 0B, Reactor Coolant Pump Undervoltage and Underfrequency Trip Setpoints.
5.38 Dominion Virginia Power Calculation EE-0457, Revision 1, CSA Calculation for Turbine First Stage Pressure, Steam Break Protection and High Steam Flow SI Actuation, Surry Power Station Units 1 and 2.
5.39 Dominion Virginia Power Calculation EE-0131, Revision 4, SPS Reactor Containment Pressure: Narrow Range Pressure Indication and Protection CSA.
5.40 Dominion Virginia Power Calculation EE-0141, Revision 1, Insulation Resistance (IR) Effects for Environmentally Qualified (EQ) Instrumentation.
5.41 Dominion Virginia Power Calculation EE-0112, Revision 2, with Add. 00A, Refueling Water Storage Tank Level Uncertainty.
5.42 Dominion Virginia Power Calculation EE-0724, Revision 0, Canal Level Probe Channel Statistical Accuracy Calculation Channel Numbers: 1-CW-LS-102. 1-CW-LS-103. 2-CW-LS-202. 2-CW-LS-203.
5.43 ISA-RP67.04.02-2000, Methodologies for the Determination of Setpoints for Nuclear Safety-Related Instrumentation.
5.44 North Anna Instrument Calibration Procedure 1-ICP-RC-P-1455, Revision 4, Pressurizer Pressure Protection Channel 1 (1-RC-P-1455) Calibration.
EE-0116 Page 199 of 205 Revision 7 5.45 North Anna Instrument Calibration Procedure 1-ICP-LO-PS-609-4, Revision 11, Reactor Trip From Turbine Trip Auto Stop Oil Pressure Switch (LO-PS-609-4) Calibration.
5.46 North Anna Instrument Calibration Procedure ICP-NI-1-N-41, Revision 36, Power Range Channel N-41 Protection Channel I.
5.47 North Anna Instrument Calibration Procedure ICP-RC-1-T-1412, Revision 33, Reactor Coolant Delta T/
TAVG Protection Channel I (1-RC-T-1412) Calibration.
5.48 North Anna Instrument Calibration Procedure 1-ICP-FW-L-1474, Revision 15, Steam Generator A Narrow Range Level Protection Channel I (1-FW-L-1474) Calibration.
5.49 North Anna Instrument Calibration Procedure 1-ICP-MS-F-1474, Revision 24, Steam Generator A Steam Flow and Feed Flow Protection Channel III (1-MS-F-1474 and 1-FW-F-1477) Calibration.
5.50 North Anna Instrument Calibration Procedure 1-ICP-MS-P-1474, Revision 6, Steam Line A Steam Pressure Protection Channel II (1-MS-P-1474) Calibration.
5.51 North Anna Instrument Calibration Procedure 1-ICP-NI-N-31, Revision 8, NIS Source Range Channel I (N-31) Calibration.
5.52 North Anna Instrument Calibration Procedure 1-ICP-QS-L-100A, Revision 10, Refueling Water Storage Tank Level Channel III (1-QS-L-100A) Calibration.
5.53 North Anna Instrument Calibration Procedure 1-ICP-RC-F-1414, Revision 4, Reactor Coolant Flow Loop A Protection Channel I (1-RC-F-1414) Calibration.
5.54 North Anna Instrument Calibration Procedure 1-ICP-RC-L-1459, Revision 4, Pressurizer Level Protection Channel 1 (1-RC-L-1459) Calibration.
5.55 orth Anna Instrument Calibration Procedure 1-ICP-LM-P-100B, Revision 2, Reactor Containment Pressure Protection Channel II (1-LM-P-100B) Calibration.
5.56 North Anna Instrument Calibration Procedure ICP-MS-1-P-1446A, Revision 20, P-1446A, First Stage Pressure Protection Channel III (1-MS-P-1446A) Calibration.
5.57 North Anna Instrument Calibration Procedure ICP-NI-1-N-35, Revision 22, Intermediate Range Channel N-35.
5.58 Surry Instrument Periodic Test Procedure 1-IPT-CC-CS-L-100A, Revision 7, Refueling Water Storage Tank Level Loop L-100A Channel Calibration.
5.59 Surry Instrument Periodic Test Procedure 1-IPT-CC-FW-F-476, Revision 13, Feedwater Flow Loop F 476 Channel Calibration.
EE-0116 Page 200 of 205 Revision 7 5.60 Surry Instrument Periodic Test Procedure 1-IPT-CC-FW-L-474, Revision 10, Steam Generator Level Protection Loop L-1-474 Channel Calibration.
5.61 Surry Instrument Periodic Test Procedure 1-IPT-CC-LM-P-100A, Revision 11, Containment Pressure Loop P-LM-100A Channel Calibration.
5.62 Surry Instrument Periodic Test Procedure 1-IPT-CC-MS-F-474, Revision 14, Steam Line Flow Protection Loop F-1-474 Channel Calibration.
5.63 Surry Instrument Periodic Test Procedure 1-IPT-CC-MS-P-446, Revision 13, Turbine Load Loop P-1-446 Channel Calibration.
5.64 Surry Instrument Periodic Test Procedure 1-IPT-CC-MS-P-464, Revision 3, Steam Header Pressure Loop P-1-464 Channel Calibration.
5.65 Surry Instrument Periodic Test Procedure 1-IPT-CC-MS-P-474, Revision 8, Steam Line Pressure Loop P-1-474 Channel Calibration.
5.66 Surry Instrument Periodic Test Procedure 1-IPT-CC-RC-F-414, Revision 10, Reactor Coolant Flow Loop F-1-414 Channel Calibration.
5.67 Surry Instrument Periodic Test Procedure 1-IPT-CC-RC-L-459, Revision 17, Pressurizer Level Protection Loop L-1-459 Channel Calibration.
5.68 Surry Instrument Periodic Test Procedure 1-IPT-CC-RC-P-455, Revision 12, Pressurizer Pressure Protection Loop P-1-455 Channel Calibration.
5.69 Surry Instrument Periodic Test Procedure 1-IPT-CC-RC-T-412, Revision 29, Delta T and TAVG Protection Set I Loop T-1-412 Channel Calibration.
5.70 North Anna Maintenance Operating Procedure 1-MOP-55.80, Revision 5, Turbine Stop Valve Closure Position Indication Instrumentation.
5.71 Engineering Transmittal ET-NAF-970142, Revision 0, Surry Technical Specification 3.2 Limiting Safety Settings, Protective Instrumentation Modification to Surveillance Procedures Surry Power Station Units 1 and 2.
5.72 Engineering Transmittal CEE-97-029, Revision 0, Comments on NAF Engineering Transmittal ET-NAF-970142, Revision 0 (DRAFT), Surry Power Station Units 1 & 2.
5.73 Technical Report EE-0068, Revision 0 (AR), Instrument Tolerances for Westinghouse/Hagan 7100 Process Protection and Control System, Surry Power Station.
5.74 Calculation SM-932, Revision 0, with Add. 00A and 00B, Surry Core Uprating Rod Withdrawal at Power.
EE-0116 Page 201 of 205 Revision 7 5.75 Calculation SM-0933, Revision 0, Generation of OTT, OPT and F(I) Function Constants for Surry Core Uprating.
5.76 NAF Technical Report NE-680, Revision 1, Analysis and Evaluations Supporting Implementation of STAT DNB and a 1.62 Fh at Surry Units 1 and 2.
5.77 59-DCP-06-013, NRC GSI-191, RWST Level ESFAS Function to Support Containment Sump Modifications / North Anna / Unit 2.
5.78 Engineering Transmittal CEE 98-005, Revision 0, Intake Canal Level Trip Setpoint Procedural Changes, Surry Power Station, Units 1 and 2.
5.79 Calculation ME-0318, Revision. 0, Add. 0A, Canal Level Probe Response Time.
5.80 Surry Instrument Periodic Test Procedure 1-IPT-CC-CW-L-102, Revision 10, Intake Canal Level Probe 1-CW-LS-102 Time Response Test and Channel Calibration.
5.81 Surry Instrument Periodic Test Procedure 1-PT-1.2, Revision 21, NIS Power Range Trip Channel Test.
5.82 Surry Instrument Periodic Test Procedure 1-PT-1.1, Revision 36, NIS Trip Channel Test Prior to Start-up.
5.83 Technical Report NE-1460, Revision 1, Implementation of GOTHIC Containment Analyses and Revisions to the LOCA Alternate Source Term Analysis to Support Resolution of NRC GL 2004-02 for Surry Power Station, Dated July 2006.
5.84 WCAP-11203, Improved Thermal Design Procedure Instrument Uncertainties for North Anna Units 1 &
2 Core Uprating.
5.85 Engineering Transmittal CEE-06-0010, Revision 0, Determination of RWST Level Allowable Values to Support Technical Report NE-1472 and Technical Specification Change Request N-051, North Anna Units 1 and 2, Dated 8-17-06.
5.86 Technical Report NE-1472, Revision 0, Implementation of GOTHIC Containment Analyses and Revisions to the LOCA Alternate Source Term Analysis to Support Resolution of NRC GL 2004-02 for North Anna Power Station, Dated 9-27-06.
5.87 Technical Report NE-1381, Revision 0, Evaluation of Surry Power Station Reactor Coolant System Leak Rate Calculation, Dated 8-15-2003.
5.88 Engineering Transmittal ET-NAF-08-0061, Revision 0, Implementation of Revised Safety Analysis Limit for High Pressurizer Pressure Reactor Trip, North Anna Units 1 and 2, Dated 9-9-2008.
5.89 59-DCP-06-015, NRC GSI-191, RWST Level ESFAS Function to Support Containment Sump Modifications / North Anna / Unit 1.
EE-0116 Page 202 of 205 Revision 7 5.90 Technical Specifications for Kewaunee Power Station.
5.91 Dominion Calculation C11705, Revision 0, Kewaunee Unit 1 Channel Statistical Allowance (CSA)
Calculation for the Power Range Neutron Flux High Setpoint Reactor Trip, Low Setpoint Reactor Trip and the P-10 permissive.
5.92 Dominion Calculation C10982, Revision 0, Pressurizer High Level Reactor Trip CSA.
5.93 Dominion Calculation C10818, Revision 0, Kewaunee Unit 1 Pressurizer Pressure Protection Channel Statistical Allowance (CSA) Calculation.
5.94 Dominion Calculation C11865, Revision 0, Kewaunee Unit 1 Channel Statistical Allowance (CSA)
Calculation for the Overtemperature Delta T Reactor Trip, Overpower Delta T Reactor Trip, Low-Low T Average Input to Steam Line Isolation, and Low T Average Feedwater Regulator Valve Closure.
5.95 Dominion Calculation C11006, Revision 0, Containment Pressure Channel Statistical Allowance (CSA) for Safety Injection, Main Steam Isolation, and Containment Spray Initiation.
5.96 Dominion Calculation C10819, Revision 0, Kewaunee Unit 1 Reactor Coolant Low Flow Reactor Trip Channel Statistical Allowance (CSA) Calculation.
5.97 Dominion Calculation C11116, Revision 0, Kewaunee Unit 1 Steam Generator Narrow Range Level Protection Channel Statistical Allowance (CSA) Calculation.
5.98 Dominion Calculation C10854, Revision 0, Hi & Hi-Hi Steam Flow and Low Steam Line Pressure ESF Actuation CSA.
5.99 Technical Specification Task Force Improved Standard Technical Specifications Traveler, TSTF-493, Clarify Application of Setpoint Methodology for LSSS Functions, Revision 4.
5.100 NRC Regulatory Issue Summary 2006-17, NRC Staff Position on the Requirements of 10 CFR 50.36, Technical Specifications, Regarding Limiting Safety System Settings During Periodic Testing and Calibration of Instrument Channels.
5.101 Kewaunee Calculation C11220, Revision ORIG, Determination of Forebay Low-Low- Level Trip Instrument Accuracy.
5.102 Dominion Calculation C11709, Revision 1, Addendum A, Degraded and Loss of Voltage Relay Settings, Kewaunee Power Station.
5.103 Kewaunee Surveillance Procedure SP-48-003E, Revision 17, Nuclear Power Range Channel 1 (Red) N-41 Monthly Test.
5.104 Kewaunee Surveillance Procedure SP-48-004A, Revision 27, Nuclear Power Range Channel 1 (Red) N-41 Calibration.
EE-0116 Page 203 of 205 Revision 7 5.105 Kewaunee Surveillance Procedure SP-47-011A, Revision 20, Reactor Coolant Temperature and Pressurizer Pressure Instrument Channel 1 (Red) Calibration.
5.106 Kewaunee Surveillance Procedure SP-36-014B-1, Revision D, Reactor Coolant Flow Channel 411 (Red) Instrument Calibration.
5.107 Kewaunee Surveillance Procedure SP-06-031A-1, Revision 3, Steam Generator Steam Pressure Loop 468 Transmitter Channel 1 (Red) Calibration.
5.108 Kewaunee Surveillance Procedure SP-06-034B-1, Revision 13, Steam Generator Flow Mismatch and Steam Pressure Instrument Channel 1 (Red) Calibration.
5.109 Kewaunee Surveillance Procedure SP-36-017B-1, Revision 2, Pressurizer Level Instrument Channel 426 (Red) Calibration.
5.110 Kewaunee Surveillance Procedure SP-18-043, Revision 27, Containment Pressure Instrument Channels Test.
5.111 Kewaunee Surveillance Procedure SP-18-044B, Revision 23, Containment Pressure Instrument Calibration.
5.112 Kewaunee Surveillance Procedure SP-05A-028B-3, Revision 3, Steam Generator Level Instrument Channel 463 (Yellow) Calibration.
5.113 Kewaunee Power Station Offsite Dose Calculation Manual (ODCM), Revision 11, February 22, 2007.
5.114 Kewaunee Power Station Updated Safety Analysis Report, Revision 21.3, dated 6/30/09.
5.115 Kewaunee Calculation C10690, Revision A, ODCM Setpoint Calculations.
5.116 Kewaunee Surveillance Procedure SP-48-287A-4, Revision 13, Intermediate Range N-35 Drawer Calibration.
5.117 Kewaunee Surveillance Procedure SP-48-287A-1, Revision G, Source Range N-31 Drawer Calibration.
5.118 ISA-RP67.04-Part II-1994, Methodologies for the Determination of Setpoints for Nuclear Safety-Related Instrumentation.
5.119 Surry Technical Specification Change Request No. 318 (Revised Setting Limits and Overtemperature &
Overpower T Time Constants) Licensing Amendments DPR-32 Amendment No. 261 and DPR-37 Amendment No. 261.
5.120 Technical Report No. EE-0039 Revision 0, Flow Channel Uncertainties, North Anna and Surry Power Stations.
EE-0116 Page 204 of 205 Revision 7 5.121 Kewaunee Surveillance Procedure SP-04-135, Revision 20, Forebay Area Water Level Instruments Calibration.
5.122 Kewaunee Surveillance Procedure SP-45-049.11, Revision 21, RMS Channel R-11 Containment Particulate Radiation Monitor Quarterly Functional Test.
5.123 Kewaunee Surveillance Procedure SP-45-049.12, Revision Z, RMS Channel R-12 Containment Gas Radiation Monitor Quarterly Functional Test.
5.124 Kewaunee Integrated Logic Diagram Radiation Monitoring E-2021, Revision AG.
5.125 Kewaunee Instrument Calibration Procedure MA-KW-ISP-RM-001-23, Revision 1, RMS Channel R-23 Control Room Ventilation Radiation Monitor Quarterly Functional Test.
5.126 Dominion Calculation C11890, Revision 0, Kewaunee Unit 1 Reactor Coolant Pump Underfrequency Trip Channel Statistical Allowance (CSA) Calculation.
5.127 Kewaunee Electrical Surveillance Procedure MA-KW-ESP-EHV-001A, Revision 3, BUS 1-1 4KV Voltage and Frequency Test and Calibration.
5.128 Dominion Calculation C11891, Revision 0, Kewaunee Unit 1 Reactor Coolant Pump Undervoltage Reactor Trip Channel Statistical Allowance (CSA) Calculation.
5.129 Kewaunee Electrical Preventive Maintenance Procedure MA-KW-EPM-EHV-015, Revision 0, BUS 1-5 Loss of Voltage Relay Calibration.
5.130 Kewaunee Drawing XK-100-621, Revision 3N, Interconnection Wiring Diagram.
5.131 Kewaunee DCR 2172, Provide Overall System Upgrade of Process and Area Rad Monitoring Systems.
5.132 Kewaunee Surveillance Procedure SP-54-059, Revision 29, Turbine First Stage Pressure Loop Calibration.
5.133 Kewaunee Power Station Technical Requirements Manual, Core Operating Limits Report (COLR)
Cycle 29, Revision 2.
5.134 Kewaunee Alarm Response Procedure OP-KW-ARP-47062-A, Revision 0, S/G A Program Level Deviation.
5.135 Kewaunee Drawing E-2006, Revision T, Integrated Logic Diagram Feedwater System.
5.136 7300 Process Instrumentation Scaling, I&C Training Manual, Westinghouse Nuclear Training Services, Copyright 1981, Westinghouse Electric Corporation.
5.137 WCAP-8773, Calculation Manual Westinghouse 7100 Series Process Control Systems, Dated April 1976.
EE-0116 Page 205 of 205 Revision 7 5.138 WCAP-10298-A, Dropped Rod Methodology for Negative Rate Trip Plants, June 1983.
5.139 Surry Power Station Design Change DCP 07-047, Implement Requirments of TSCR 318 / Surry / Units 1 & 2.
5.140 Kewaunee Instrument Surveillance Procedure MA-KW-ISP-SW-001A, Revision 2, Service Water Header A Pressure Switch Calibration.
5.141 Kewaunee Calculation C11345, Revision A, Addendum B, Re-evaulation of Turbine Building SW Header Isolation Set point.
5.142 Kewaunee Condition Report CR361418, Improved Technical Specifications Change to Nuclear Instrumentation System Rate Trips.
5.143 Kewaunee Surveillance Procedure SP-45-049.21, Revision 23, RMS Channel R-21 Containment Stack Radiation Monitor Quarterly Functional Test.
5.144 Kewaunee Instrument Calibration Procedure ICP-54-30, Rev. 12, TB-Turbine Pressure Switches and Indicators Calibration.