ML101040090

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License Amendment Request 249: (TAC ME02467) Conversion to Improved Technical Specifications - Setpoint Methodology
ML101040090
Person / Time
Site: Kewaunee Dominion icon.png
Issue date: 04/13/2010
From: Price J
Dominion Energy Kewaunee
To:
Document Control Desk, Office of Nuclear Reactor Regulation
References
09-491B, TAC ME02467
Download: ML101040090 (38)
v • d • e


Text

Dominion Energy Kewaunee, Inc.

5000 Dominion Boulevard, Glen Allen, VA 23060 April 13, 2010 ATTN: Document Control Desk Serial No.09-491 B U. S. Nuclear Regulatory Commission L1C/GOR/RO Washington, DC 20555-0001 Docket No.: 50-305 License No.: DPR-43 DOMINION ENERGY KEWAUNEE, INC.

KEWAUNEE POWER STATION LICENSE AMENDMENT REQUEST 249: (TAC NO. ME02467) CONVERSION TO IMPROVED TECHNICAL SPECIFICATIONS - SETPOINT METHODOLOGY Pursuant to 10 CFR 50.90, Dominion Energy Kewaunee, Inc. (DEK) requested an amendment to Facility Operating License Number DPR-43 for Kewaunee Power Station (KPS) (Reference 1). This license amendment request (KPS LAR-249) would revise the KPS current Technical Specifications (CTS) to Improved Technical Specifications (ITS) consistent with the Improved Standard Technical Specifications (ISTS) described in NUREG 1431, "Standard Technical Specifications - Westinghouse Plants," Revision 3.0.

In Reference 1, DEK proposed adoption of Technical Specification Task Force (TSTF) traveler TSTF-493, "Clarify Application of Setpoint Methodology for LSSS Functions,"

Revision 4, Option B for the KPS ITS and marked up the proposed ITS pages accordingly. Option B allows the relocation of instrumentation allowable values from the Technical Specifications to a licensee control. TSTF-493, Rev. 4, states that a request to adopt Option B requires submittal and NRC approval of the setpoint methodology or methodologies that a plant desires to use to calculate future setpoint changes. The enclosed document provides the proposed setpoint methodology for KPS. The methodology is referenced in proposed KPS ITS specification 5.5.16, "Setpoint Control Program," item b.1.

TSTF-493, Rev. 4 was submitted to the NRC by the TSTF on July 31, 2009 (ADAMS Accession No. ML092150990) and is currently under NRC review. DEK used TSTF-493, Rev. 4 in the development of LAR-249 (Reference 1). However, since the NRC staff has not yet completed its review of TSTF-493, Rev. 4, there may be some differences between the final approved version of TSTF-493 and the proposed KPS technical specifications.

After submittal of LAR 249, DEK submitted a technical report that provided the setpoint methodology for those instruments included in the KPS Setpoint Control Program (Reference 2). Although this technical report included the setpoint methodology DEK is requesting approval to use, additional information on how the methodology will be used

Serial No.09-491 B Page 2 of 3 was included in the technical report. During a teleconference between members of the NRC and DEK staffs on March 11, 2010, it was agreed that a new technical report containing only the setpoint methodology should be submitted. The intention of submitting only the setpoint methodology is to avoid potential confusion regarding what aspects of the methodology are actually being reviewed and approved by the NRC staff.

Therefore, as an enclosure to this letter DEK is providing the NRC with a technical report containing only the KPS specific setpoint methodology information.

Enclosed is Technical Report No. EE-0132, Revision 0, "Setpoint Methodology for Kewaunee Power Station, Kewaunee Unit 1, Kewaunee Electricalll&C Design," dated March 2010.

Dominion continues to request approval of the proposed amendment and an implementation period as stated in Reference 1. In addition, the information contained in this supplement does not alter the no significant hazards consideration determination contained in Reference 1.

A copy of this letter has been provided to the State of Wisconsin in accordance with 10 CFR 50.91 (b).

If you have any questions or require additional information, please contact Mr. Gerald O. Riste at (920) 388-8424.

Serial No.09-491 B Page 3 of 3 Very truly yours, Price resident - Nuclear Engineering COMMONWEALTH OF VIRGINIA COUNTY OF HENRICO The foregoing document was acknowledged before me, in and for the County and Commonwealth aforesaid, today by J. Alan Price, who is Vice President - Nuclear Engineering of Dominion Energy Kewaunee, Inc. He has affirmed before me that he is duly authorized to execute and file the foregoing document in behalf of that Company, and the statements in the document are true to the best of his kn/..OWle:e and b Acknowledged before me this '3 "" day of . . A

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  • Technical Report No. EE-0132 Revision 0, "Setpoint Methodology for Kewaunee Power Station, Kewaunee Unit 1, Kewaunee Electrical/I&C Design," March 2010.

References:

1. Letter from Leslie N. Hartz (DEK) to Document Control Desk (NRC), "License Amendment Request 249: Kewaunee Power Station Conversion to Improved Technical Specifications (TAC NO. ME02467)," dated August 24, 2009. [ADAMS Accession No's ML092440371, ML092440416 through ML092440435, and ML092440441 ]
2. Letter from J. Alan Price (DEK) to Document Control Desk (NRC), "License Amendment Request 249: Kewaunee Power Station Conversion to Improved Technical Specifications (TAC No. ME02467) - Setpoint Methodology Supplement," dated October 22,2009. [ADAMS Accession No. ML093070096]

Commitments made by this letter: None cc: Regional Administrator, Region III

Serial No.09-491 B Page 4 of 3 U. S. Nuclear Regulatory Commission 2443 Warrenville Road Suite 210 Lisle, IL 60532-4352 Mr. P. S. Tam Sr. Project Manager U.S. Nuclear Regulatory Commission One White Flint North, Mail Stop 08-H4A 11555 Rockville Pike Rockville, MD 20852-2738 Mr. V. G. Cusumano NRC KPS ITS Conversion Lead U.S. Nuclear Regulatory Commission One White Flint North Mail Stop 0-7 C2A 11555 Rockville Pike Rockville, MD 20852-2738 NRC Senior Resident Inspector Kewaunee Power Station Public Service Commission of Wisconsin Electric Division P.O. Box 7854 Madison, WI 53707

Serial No.09-491 B ENCLOSURE LICENSE AMENDMENT REQUEST 249: KEWAUNEE POWER STATION CONVERSION TO IMPROVED TECHNICAL SPECIFICATIONS (TAC NO. ME02467)

TECHNICAL REPORT NO. EE-0132, REVISION 0 SETPOINT METHODOLOGY FOR KEWAUNEE POWER STATION KEWAUNEE UNIT 1 KEWAUNEE ELECTRICAL II&C DESIGN MARCH 2010 KEWAUNEE POWER STATION DOMINION ENERGY KEWAUNEE, INC.

Serial No.09-491 B ENCLOSURE LICENSE AMENDMENT REQUEST 249: KEWAUNEE POWER STATION CONVERSION TO IMPROVED TECHNICAL SPECIFICATIONS (TAC NO. ME02467)

TECHNICAL REPORT NO. EE-0132, REVISION 0 SETPOINT METHODOLOGY FOR KEWAUNEE POWER STATION KEWAUNEE UNIT 1 KEWAUNEE ELECTRICAL II&C DESIGN MARCH 2010 KEWAUNEE POWER STATION DOMINION ENERGY KEWAUNEE, INC.

Technical Report Cover Sheet EE~0132, Rev. 0 NDaM~~M 1 ~, ~ "' ~ , Attachment 1 TECHNICAL REPORT No. EE"'()132 J REVISION 0 SETPOINT METHODOLOGY FOR KEWAUNEE POWER STATION KEWAUNEE UNIT 1 KEWAUNEE ELECTRICAL II&C DESIGN March 2010 Prepared By: (li~~' ft1C?--- Date ..~"2 - /7 *-ut'"

Prepared By: VtfM/4 'llff/hatv Date 2-/g-;).o/O Reviewed Bykj.- ~~Y' Date 3*>B .. )0 Date 3/rt/ftJ Date 3/i'Llo QA Category SR Key Words: Allowable Values As Found Tolerances ESFAS Jnstrumentation Improved Technical Specifications Limiting Safety System Settings Reactor Protection System Instrumentation Setting Limits Setpoints (June 2006)

EE-0132 Revision 0 Record of Revision Rev 0 Original Issue. The Setpoint Methodology described in this Technical Report is taken from Technical Report EE-0116, Revision 6, "Allowable Values For North Anna Improved Technical Specifications (ITS) Tables 3.3.1-1 and 3.3.2-1, Setting Limits for Surry Custom Technical Specifications (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". The Setpoint Methodology described in Technical Report EE-0116, Revision 6 and in this Technical Report was previously screened via VPAP-0301 (Safety Review) and DNAP-3004 (50.59/72.48 Screen) as documented in Engineering Transmittal ET-CEE-09-0009, Revision 1 "Transmittal of Design Input Information Based on the Results of Technical Report EE-0116, Revision 6 and Associated Channel Statistical Allowance Calculations".

EE-0132 Page 1 of30 Revision 0 TABLE OF CONTENTS SECTION PAGE

1.0 INTRODUCTION

2 1.1 Purpose 2 1.2 Scope 2 2.0 OVERVIEW 3 2.1 Defmitions 3 2.2 The Significance ofthe Allowable Value 6 2.2.1 Background 6 2.2.2 Addressing Recent NRC Concerns Associated With Allowable Values 6 2.2.3 The NRC StaffPosition Concerning the LSSS and AV 7 2.2.4 The ISA/ NEWarious Industry Groups Position Concerning the LSSS and AV 8 2.2.5 The Dominion Position Concerning the LSSS and AV for Kewaunee 9 3.0 METHODOLOGY 10 3.1 Introduction 10 3.2 Functional Groups for RPS and ESFAS Instrumentation 10 3.3 The Instrumentation, Systems and Automation Society (ISA) Methodologies Used to Calculate Allowable Values 17 3.3.1 Method 1 18 3.3.2 Method 2 19 3.3.3 Method 3 20 3.3.4 Method 3 with Additional Margin 21 3.4 Methodology for Determining Kewaunee's "Allowable Value" and "Limiting Trip 22 Setpoint" Based on TSTF-493 and RIS 2006-17 3.4.1 PrimaryRPS and ESFAS Trips, Permissives, and Other LCO's Credited in the 22 Kewaunee Safety Analysis 3.4.2 Backup RPS and ESFAS Trips, Permissives and Other LCO's Not Credited in the 24 Kewaunee Safety Analysis 3.4.3 Calculating Limiting Trip Setpoints, Allowable Values, and As Found 25 Tolerances for Kewaunee Power Station

4.0 REFERENCES

29

EE-0132 Page 2 of30 Revision 0

1.0 INTRODUCTION

1.1 Purpose The purpose of this docmnent is to provide a comprehensive and controlled reference which details the design basis for the Allowable Values that appear in the Kewaunee Power Station Setpoint Control Program.

1.2 Scope

Limiting Trip Setpoints, Nominal Trip Setpoints, Allowable Values, As Found Tolerances, and As Left Tolerances to be used in Kewaunee Power Station's Setpoint Control Program to support the conversion to hnproved Technical Specifications.

  • This docmnent 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 Station's Setpoint Control Program to support the conversion to hnproved Technical Specifications.

  • This docmnent 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 Station's Setpoint Control Program to support the conversion to hnproved Technical Specifications.
  • This docmnent 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 Station's Setpoint Control Program to support the conversion to hnproved Technical Specifications.
  • The nmnerical values that appear in this Technical Report are for illustrative purposes only.

EE-0132 Page 3 of30 Revision 0 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 CAY) - is the threshold value used to detennine 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 11-1994.

Analytical Limit CAL) - 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) -The As Found Tolerance is equal to the statistical combination of the rack error components and rack drift.

As Left Tolerance (ALT) -The As Left Tolerance is equal to the statistical combination of the rack error components minus the rack drift.

Calibrated Range - The calibration span ofthe sensor/transmitter as it applies to the indicated process range ofthe 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. 4.4).

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 nonnally includes the following five elements; the process, a transmitter/sensor, process electronics, indications and/or automatic control elements.

Limiting Safety System Setting (LSSS) - The LSSS is a term used to defme 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 LSSS is equivalent to the As Found Tolerance for Kewaunee.

EE-0132 Page 4 of30 Revision 0 Limiting Trip Setpoint (LTSP) - Based on TSTF-493, Rev. 4 and RIS 2006-17, the LTSP is the limiting setting for the channel trip setpoint considering all credible instrument errors associated with the instrument channel (Refs. 4.12 and 4.13).

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 TSTF-493, Rev. 4 and RIS 2006-17 (Refs. 4.12 and 4.13), 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 (Ml, 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/As Found Tolerance.

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 value's of a process parameter or the signal values corresponding to these.

Tolerance - The allowable deviation from an ideal calculated value.

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 ofTLU/CSA error terms is provided in Table 2.1 below.

EE-0132 Page 5 of30 Revision 0 Table 2.1: Channel Statistical Allowance (CSA) Equation and Error Term Definitions CSA = SE +/- lEA2 + PMA2 + PEA2 + (SCA+SMTE)2 + sn2 + SPE22 + STE22 + SPSE2 2 + (M1+MIMTE)2 +

(M2+M2MTE)2+ ... + (Mn+MnMTEi+ RD + RTE + RRA ]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 ofInsulation 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 ofSMTE 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 (Ml through Mn) Module Ml 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 (Ml 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-0132 Page 6 of30 Revision 0 2.2 The Significance of the Allowable Value 2.2.1 Background Historically, for plants that have used Westinghouse Standardized Technical Specifications (STS), two values have been provided for each Reactor Protection System (RPS) 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 Kewaunee (CTS), normally only one setpoint value (assumed to be the Limiting Safety System Setting "LSSS" or the Setting Limit) 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 defmition 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 ofretained/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), Le., also known as the Safety Analysis

EE-0132 Page 7 of30 Revision 0 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 layout 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 ofthe LSSS. These items will be addressed in this document as they apply to Kewaunee.

At the present time, Kewaunee Power Station is using Custom Technical Specifications (CTS). 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, Revision 4 (Ref. 4.12). The Setpoint Control Program will be administered as defmed in ITS, Section 5.5.16 "Setpoint Control Program". 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)(I)(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 (A V) 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

EE-0132 Page 8 of30 Revision 0 RIS 2006-17 (Ref. 4.13), the NRC's 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 2.2.5.(1) 2.2.4 The ISAlNEIIVarious 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.
  • The Trip Setpoint (TSP) protects the AL.

Summary

  • The AV, based on a portion of the errors, does not invalidate the TSP.
  • The AV validates an error contribution assumption via periodic surveillance testing.
  • As long as the AV is not exceeded, the channel is OPERABLE.
  • During Surveillance Testing, the AV serves as the LSSS.

In summary, ISA/NEINarious 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. Dominion's implementation of the requirements set forth in TSTF-493, Revision 4 (Ref. 4.12) as they apply to Kewaunee Power Station will be addressed in Sections 2.2.5 and 3.4.

(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-0132 Page 9 of30 Revision 0 2.2.5 The Dominion Position Concerning the LSSS and AV for Kewaunee Dominion has decided to adopt hnproved Technical Specifications (ITS) for Kewaunee. As part of the ITS conversion, Dominion has chosen to implement Option B ofTSTF-493, Revision 4 (Ref. 4.12). 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 defmed 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. 4.12 and 4.13) 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 Kewaunee's 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. 4.13). This revised position is a change from the historical defmition of the Allowable Value as delineated in Standardized Technical Specifications (STS), i.e., "A setting chosen to prevent exceeding a Safety Analysis Limit" (Ref. 4.3). 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 3.4. With respect to Kewaunee's conversion to ITS, Dominion agrees with this revised position based on explanations and guidance provided in TSTF-493, Revision 4 and RIS 2006-17.

Kewaunee's 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 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, Kewaunee's Setpoint Methodology will incorporate the revised terminology and additional requirements imposed by TSTF-493, Revision 4 and RIS 2006-17. A detailed discussion of Kewaunee's Setpoint Methodology incorporating the revised terminology and requirements from TSTF-493 and RIS 2006-17 is provided in Section 3.4.

EE-0132 Page 10 of30 Revision 0 3.0 METHODOLOGY 3.1 Introduction Many Westinghouse Plants continue to use Westinghouse or other Engineering Finns to perfonn some or all of their Safety Analysis Functions. In addition, Westinghouse has also perfonned the RPS 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 RPS 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. .

Kewaunee is unique in the fact that a majority of the USAR Chapter 14 Safety Analysis is perfonned in house by the Corporate Nuclear Analysis & Fuels Department. In addition, Channel Statistical Allowance Calculations for Primary and Backup RPS and ESFAS Trip Functions are perfonned in house by the Corporate ElectricallI&C/Computers Department. Because Dominion perfonns their own Safety Analysis and CSA Calculations, the methodology used to detennine Improved Technical Specifications (NUREG-1431 "ITS") As Found Tolerances for Kewaunee will be similar and in some cases more conservative than that used by Westinghouse in the past to detennine Allowable Values for later versions of Standardized Technical Specifications. In addition, the methods used to calculate the limiting values for Kewaunee will be consistent with the requirements ofMethods 1 or 2 as described in ISA-RP67.04.02-2000 (Ref 4.7).

3.2 Functional Groups for RPS and ESFAS Instrumentation.

Based on Dominion Technical Report NE-0994 (Ref. 4.2), the Reactor Protection System (RPS) and the Engineered Safety Features Actuation System (ESFAS) Instrumentation at Kewaunee 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 ESFAS Actuation Functions
  • Primary ESFAS Pennissives

EE-0132 , Page 11 of 30 Revision 0 Backup Trip Functions include the following:

  • Backup ESFAS Permissives In addition to the above, there are three basic functional groups of Westinghouse Nuclear Instrumentation System (NIS), Foxboro H-Line, and NUS Replacement Modules Instrumentation that develop the majority of the RPS and ESFAS trips. These basic functional groups are divided into the three categories listed below:
1. Single parameter protection function
2. Dual Parameter Protection Functions
3. Multiple parameter protection function (i.e., more than two process parameters)

Different methods are used to calculate or validate the As Found Tolerances for Kewaunee depending on whether the function is considered to be Primary or Backup. In addition, the functional group category will also effect how the As Found Tolerance is calculated. Some examples of functional groups are given below.

Single Parameter Protection Functions

  • Compensated Low Steam Line Pressure ESFAS initiation

Multiple Parameter Protection Functions

EE-0132 Page 12 of30 Revision 0 Single Parameter Protection Functions Kewaunee The NSSS Protection and Control System at Kewaunee uses the Westinghouse Nuclear Instrumentation System (NIS) 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). Most of the RPS and ESFAS trips generated from these systems are single parameter protection functions.

Figure 3.2-1 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 Flcm Loop P""",

Supply Module HI61IlAC-D or NUS

+/~ 0.0%

FS-411 TJ

+}t--t--- F/411 C D 4872202 L-NE FC-411 RC LowFlcm 120VAC RXTrip Channel Bistable Bistable Test TaRPS Test S\\itch Relay Log ic H/63U-AC-OHAA ar Ta Other Loop NUS C<JlTllOIl"nts +/~ 0.5%

Figure 3.2-1 Refer to Figure 3.2-1 :

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.

EE-0132 Pa~e 13 of30 Revision 0 In the case of Kewaunee's Low Reactor Coolant Flow Reactor Trip as shown in Figure 3.2-1, the rack error terms from CSA Calculation C10819 (Ref. 4.10) 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 %

Dual Parameter Protection Functions Kewaunee The Overpower IIT Reactor Trip is the only dual parameter protection function at Kewaunee. Figure 3.2-2 is a block diagram that illustrates Kewaunee's Overpower llT Reactor Trip, Overtemperature llT Reactor Trip, and the Low T AVG trip functions.

As can be seen from Figure 3.2-2, Kewaunee's Overpower llT Reactor Trip function is derived from two process parameters, they are :

  • T HOT
  • TCOLD NOTE: The FM input is set to zero The Overpower IIT Reactor Trip function is further broken down into channels as defmed below:
  • IIT Channel, made up of THOT and TCOLD
  • TAVG Channel, made up ofTHoT and TCOLD The Overpower IIT Reactor Trip function is considered to be a Backup Reactor Trip Function at Kewaunee, therefore the Allowable Value, As Found Tolerance, and As Left Tolerance will be based on the COT error components taken from the Channel Statistical Allowance Calculation of record.

Developing an Allowable Value, As Found Tolerance, and As Left Tolerance based on Methods 1 or 2 from ISA-RP67.04.02-2000 (Ref 4.7) is not applicable for trip functions that do not have an associated Analytical Limit.

EE-0132 Page 14 of30 Revision 0 Multiple Parameter Protection Functions Kewaunee There are two multiple parameter protection functions at Kewaunee. Figure 3.2-2 is a block diagram that illustrates Kewaunee's Overtemperature ~T Reactor Trip configuration (note that Overpower ~T and Low TAVG are also shown on the drawing).

Kewaunee Power Station Overtemperature ~T Reactor Trip TFA01A

<: TT-401A Foxboro or NUS

,... DB Box 08-1 TM-405R Foxboro E1E DB Box De~a T

? RdfR1D (Thol)

R'E Converter (Thot) M1 De~T Lead/Lag Ul~

(De~a T)

M3 08-2 Delta T De~a T r+

TFA01B

'<: TT-401B Foxboro or NUS f-+ TM-401BB Foxboro Elt DB Box 08-3 TM-401-0 Foxboro OR NUS TAVG

-------+ Lead/Lag Ul~

1---+ ~

? RlE Converter 1--4 (TAVG) rrpulse Leadl Lag Ul~ (TAVG)

RdfR1D (Tcold) M2 TAVG (Tcold) M4 M5 TC-401A1D Foxboro or NUS Lo-Lo

-- StmUna Isol Bistable

~ StmLine TAVG A"essurizer A"essure L TM-401V Foxboro OroTSPZ Sunmator M6 f---

TAVG TAVG M8 TC-401F Isolation CH.1

~ aosure Foxboro or NUS ow TAVG L. FRV Oose FRV

-- I PQ-429 DB Box TM-401B Bistable Roserrount Foxboro or NUS 08-7 M9 Foxboro OTDT 1---+ f-------. t--

r Model Power Supply SP1 LeadlLag TAVG 1154SH9 M10 PZR Un~ M7 DB Box L.-+ TC-405A1B 4 08-4 l!!l DAM 9000

~

QU OroT OroT Bistable TAVG Overpow er De~a T SP RXTrip rl..

NM306 M17 TC-405L

'Ii. Foxboro or NUS Isolation Arrp Qu > a Controller DB Box r+ F\)Q M11 M13 08-6 au f-----+ TM-401T Foxboro De~ Q J TC-405CID l!!l DAM 9000 r

Signal selector M15 DB Box OTDT Bistable ~ OTDT QL f-----+ L.-.

08-5 OTDT Overterrperature Delta T SP M18 RXTrip QI STPT NM307

'Ii. + TC-401R Foxboro or NUS '--- TM*401U Isolation Arrp M12 - .... a > au Controller M14 F\)Q J

Foxboro Delta Q Current Source M16 Figure 3.2-2 As can be seen from Figure 3.2-2, Kewaunee's Overtemperature ~T Reactor Trip function is derived from five process parameters, they are:

  • THOT
  • T coLD
  • Pressurizer Pressure
  • Function of Delta Flux (FM) made up of Upper Flux (Qu) and Lower Flux (Qd

EE-0132 Page 15 of30 Revision 0 The Overtemperature L\T Reactor Trip function is further broken down into channels as defined below :

  • L\T Channel, made up of T HOT and T COLD
  • TAVG Channel, made up of THOT and T COLD
  • Pressurizer Pressure Channel
  • Function of Delta Flux (FL\I), made up of Qu and QL Because there are five inputs to Kewaunee's Overtemperature L\T function, the rack error components will be grouped as channel inputs versus a string of modules as would be the case for a Single or Dual Parameter Function. This type of assessment will yield a conservative and valid As Found Tolerance using the fout step method described in Section 3.4. CSA Calculation C11865 (Ref. 4.9) was performed using a module calibration method, which for a multiple-parameter function will result in a very conservative CSA value. In the case of Kewaunee, the module calibration method was used to come up with an overall Total Loop Uncertainty and was then reduced to yield a conservative As Found Tolerance.

The rack error components for each Overtemperature L\T input channel are given below.

Pressurizer Pressure Channel = (RCA3 + RMTE 3) + RD 3 + RTE 3 OTL\T Setpoint = (RCAs + RMTEs)

OTL\T Bistable = (RCSA + RMTE6)

Where:

RCA l = L\T Channel Calibration Accuracy = +/- 0.707 % (M3)

RMTE l = L\T Channel Rack Measuring and Test Equipment = +/- 0.173 % (M3MTE)

RD l = L\T Channel Rack Drift = +/- 1.00 %

RTE l = L\T Channel Rack Temperature Effect = +/- 0.50 %

RCA2 = TAVG Channel Calibration Accuracy = +/- 0.707 % (M4)

RMTE 2 = TAVG Channel Rack Measuring and Test Equipment = +/- 0.245 % (M4MTE)

RD 2 = TAVG Channel Rack Drift = +/- 1.00 %

RTE2 = TAVG Channel Rack Temperature Effect = +/- 0.50 %

RCA 3 = Pressurizer Pressure Channel Calibration Accuracy = +/- 0.00 %

RMTE 3 = Pressurizer Pressure Channel Rack Measuring and Test Equipment = +/- 0.0 %

RD 3 = Pressurizer Pressure Channel Rack Drift = +/- 0.00 %

RTE 3 = Pressurizer Pressure Channel Rack Temperature Effect = +/- 0.00 %

RC~ = FL\I Channel Calibration Accuracy = +/- 0.50 % (MIS)

RMTE4 = FL\I Channel Rack Measuring and Test Equipment = +/- 0.346 % (M15MTE)

EE-0132 Page 16 of30 Revision 0

= FL11 Channel Rack Drift = +/- 1.00 %

= FM Channel Rack Temperature Effect = +/- 0.50 %

= OTL1T Setpoint Summator Calibration Accuracy = +/-0.50 % (M7)

= OTL1T Setpoint Summator Rack Measuring and Test Equipment = +/- 0.374 %

(M7MTE)

RCSA = OTL1T Reactor Trip Bistable = +/- 0.50 % (M18)

RMTE6 = OTL1T Reactor Trip Bistable Rack Measuring and Test Equipment = +/- 0.224 %

(M18MTE)

Some of the error terms listed above will be used to determine the As Found Tolerance for Kewaunee's Overtemperature L1T Reactor Trip.

EE-0132 Page 17 of30 Revision 0 3.3 The Instrumentation, Systems and Automation Society (lSA) 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-I 994.

Analytical Limit (AL) =6.00PSIG 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 Kewaunee, these error components are:

  • Rack or Module Calibration Accuracy (RCA or MI, 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 Kewaunee, 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 MIMTE, M2MTE ... MnMTE)
  • Rack Temperature Effect (RTE)

EE-OI32 Page 18 of30 Revision 0 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. 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.

[(0.85i + (1.lOiJ y, = 1.39 or [(1.39i - (0.85iJ y, = 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 TT LU = 1.39 NON COT f = 0.85

. _. AV=5.15PSIG 1 COT =1.10 1 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-0132 Page 19 of 30 Revision 0 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 fmd 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:

T

- - - - AL = 6.00 PSIG NON1085 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

EE-0132 Page 20 of 30 Revision 0 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:s 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 ofMethod 3 using 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 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 UNCERTAINlY COT = TESTED LOOP UNCERTAINTY CAL SP =CALCULATED SETPOINT ACT SP =ACTUAL SETPOINT Figure 3.3-3

EE-0132 Page 21 of30 Revision 0 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.

METHOD 3 WITH ADDITIONAL MARGIN*

AL = 6.00 PSIG i

T --l*-

TLU =1.39 NON COT =0.29 AV = 5.71 PSIG 1 ---+- -- 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-0132 Page 22 of30 Revision 0 3.4 Methodology for Determining Kewaunee's "Allowable Value" and "Limiting Trip Setpoint" Based on TSTF-493 and RIS 2006-17 Kewaunee's setpoint methodology incorporates the requirements and revised terminology imposed by TSTF-493 and RIS 2006-17 (Refs. 4.12 and 4.13) as appropriate. Kewaunee Power Station has chosen to implement TSTF-493, Revision 4, Option B as part of the conversion to hnproved Technical Specifications.

As stated above in Section 2.2.5, TSTF-493, Revision 4, Option B allows for the relocation of the Allowable Values associated with LCO's 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 defmed 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)(I)(ii)(A) are described in detail in a separate Technical Report that utilizes the methodology described here.

3.4.1 Primary RPS and ESFAS Trips, Permissives, and Other LCO's 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 LCO's 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 4.7) 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 3.4-1

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 ofthe NON COT Loop Error Components to the Analytical Limit (AL).

EE-0132 Page 23 of30 Revision 0

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 T t Analytical Limit (AL)

NONcJ'RROR' TOTAL LOOP UNCERTAINTY (TLU) - . - . . - - Allowable Value (AV)

(STEP 2)

I COT ERRORS

~ 1_ _ -

Limiting Trip Setpoint (LTSP)

(STEP 1)

MARGIN

- .f* - /Js Found Tolerance (AFT)

(STEP 4)

COT ERRORS Nominal Trip Setpoint (NTSP)

(STEP 3)

Figure 3.4-1

EE-0132 Page 24 of 30 Revision 0 3.4.2 Backup RPS and ESFAS Trips, Permissives, and Other LCO's 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 LCO's 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-0132 Page 25 of30 Revision 0 3.4.3 Calculating Limiting Trip Setpoints, Allowable Values, and As Found Tolerances for Kewaunee Power Station Kewaunee's Steam Generator Water Level High - High Currently, Kewaunee's Custom Technical Specifications (Ref. 4.8) do 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 3.4.1 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. 4.2). 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. 4.2)

Current CTS Setting Limit = not specified Current Nominal Trip Setpoint = 66.5 % Narrow Range Level (Ref. 4.14)

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. 4.11)

Type of Trip = Increasing Trip, Normally Energized (Ref. 4.14)

Functional Group = Primary Trip, Single Parameter Protection Function (Refs. 4.2 and 4.14)

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 Clll16 (Ref. 4.11) are detailed below:

EE-0132 Page 26 of30 Revision 0 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. 4.4), we have the following NON-COT total error:

2 NON COTerror = SE + PMA3 +/- [PEA + (SCA+SMTEi + SD2 + SPE2 + STE2 + SPSE2 + M1MTE2 +

M3MTE2 + RTE2] 1/2 NON COTerror = 0.0 + 5.945 +/- [0.02 + (0.25+0.217i + 0.2802 + 0.5772 + 1.241 2 + 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. 4.7) 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 fimction 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. 4.18 and 4.19). 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-0132 Page 27 of30 Revision 0 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 Clll16 (Ref. 4.11) 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 Clll16 are detailed below:

Module 1 - Foxboro or NUS Loop Power Supply (Ml) = +/- 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. 4.4), we have the following COT total error:

COTerror = +/- (M1 2 + M3 2 + RD2) 1/2 COTerror = +/- (0.02 + 0.5 2 + 1.02) 1/2 COTerror = +/- 1.12 % Narrow Range Level As described in Section 3.4.1 for Step 4, 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 Kewaunee's 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(l)

Steps 1 through 4 as they apply for Kewaunee's Steam Generator High-High Water Level Reactor Trip are illustrated below in Figure 3.4-2.

(1) ALT = COT error minus Rack Drift (RD) = +/- (0.0 2 + 0.5 2) Y, = +/- 0.5 % of span = +/- 0.5 % NR Level

EE-0132 Page 28 of30 Revision 0 KEWAUNEE'S STEAM GENERATOR HI-HI WATER LEVEL ESFAS Analytical Limit (AL) 100.00 NR Level

~

0::

j

~

5 ffi 0::

Z

~;

j 0q '#.

~ ........

0:: i5Z Lt'l

~~ '#...,

Z r-.

Allowable Value (AV)

~~Z Sl pj 0::

Z 92.486 % NR Level

> r-.

0:: ~m 0:: o >

W

~~

0

(.)

0 Limiting Trip Setpoint (LTSP) 92.077 % NR Level As Found Tolerance (AFT)

SA~MARGN 0 67.62. %NRLevel 25.58 % NR Level ~

ffi 8 Nominal Trip Setpoint (NTSP) l5__

66.50 % NR Level OPERATING MARGN 17.50 %NRLevel High Operating Limit 49.00 %NRLevel Nominal Operating Setpoint 44.00 % NR Level Figure 3.4-2 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 Kewaunee's RPS instrumentation, ESFAS instrumentation, and other instrumentation associated with LCD's 3.3.5, 3.3.6, and 3.3.7 in a separate Technical Report. 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 a separate Technical Report.

EE-0132 Page 29 of30 Revision 0

4.0 REFERENCES

4.1 Technical Report EE-0116, Revision 6, Allowable Values For North Anna hnproved Technical Specifications (ITS) Tables 3.3.1-1 and 3.3.2-1, Setting Limits For Surry Custom Technical Specifications (CTS), Sections 2.3 and 3.7, and Allowable Values For Kewaunee Power Station hnproved Technical Specifications (ITS) Functions Listed in Specification 5.5.16.

4.2 Technical Report NE-0994, Revision 17, Safety Analysis Limits for Technical Specification Instrumentation - Companion to EE-0101, September 2009.

4.3 Westinghouse - NAPS Reactor Protection System/Engineered Safety Features Actuation System Setpoint Methodology (NRC Letter - SIN 541, Dated 09-28-78).

4.4 Dominion Virginia Power STD-EEN-0304, Revision 6, Calculating Instrumentation Uncertainties By the Square Root of the Sum ofthe Squares Method.

4.5 Dominion Virginia Power STD-GN-0030, Revision 8, Nuclear Plant Setpoints.

4.6 USNRC Regulatory Guide 1.105, Revision 3 (December 1999), Setpoints for Safety-Related Instrumentation.

4.7 ISA-RP67.04.02-2000, Methodologies for the Determination of Setpoints for Nuclear Safety-Related Instrumentation.

4.8 Technical Specifications for Kewaunee Power Station.

4.9 Dominion CalCulation Cl1865, 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.

4.10 Dominion Calculation C10819, Revision 0, Kewaunee Unit 1 Reactor Coolant Low Flow Reactor Trip Channel Statistical Allowance (CSA) Calculation.

4.11 Dominion Calculation Clll16, Revision 0, Kewaunee Unit 1 Steam Generator Narrow Range Level Protection Channel Statistical Allowance (CSA) Calculation.

4.12 Technical Specification Task Force hnproved Standard Technical Specifications Traveler, TSTF-493, Clarify Application ofSetpoint Methodology for LSSS Functions, Revision 4.

4.13 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.

4.14 Kewaunee Surveillance Procedure SP-05A-028B-3, Revision 3, Steam Generator Level Instrument Channel 463 (Yellow) Calibration.

EE-0132 Page 30 of30 Revision 0 4.15 Kewaunee Power Station Updated Safety Analysis Report, Revision 21.6, dated 12/31/09.

4.16 ISA-RP67.04-Part 11-1994, Methodologies for the Determination of Setpoints for Nuclear Safety-Related Instrumentation.

4.17 Kewaunee Power Station Technical Requirements Manual, Core Operating Limits Report (COLR)

Cycle 30, Revision 2.

4.18 Kewaunee Alarm Response Procedure OP-KW-ARP-47062-A, Revision 0, S/G A Program Level Deviation.

4.19 Kewaunee Drawing E-2006, Revision T, Integrated Logic Diagram Feedwater System.

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