ML17083C623

Rev 4 to WCAP-13705, W Setpoint Methodology for Protection Sys Diablo Canyon Units 1 & 2,24 Month Fuel Cycle Evaluation

ML17083C623
Person / Time
Site:	Diablo Canyon
Issue date:	01/31/1997
From:	Andre S, Rood M, Scherder W WESTINGHOUSE ELECTRIC COMPANY, DIV OF CBS CORP.
To:
Shared Package
ML16342D530	List: DCL-96-214, Transmits WCAPs Supporting NRCs Review of License Amend Request 96-10,rev of TSs to Support Extended Fuel Cycles to 24 months.WCAP-11082,rev 5,WCAP-11594,rev 2 & WCAP-14646,rev 1 Withheld ML16342D531 ML16342D532 ML16342D533 ML16342D535 ML16343A474 ML17083C623
References
WCAP-13705, WCAP-13705-R04, WCAP-13705-R4, NUDOCS 9702120225
Download: ML17083C623 (118)

Text

Westinghouse Non-Proprietary Class 3

+ + + + + + + +

Westinghouse Setpoint Methodology for Protection Systems Diablo Canyon Units 1 8c 2 24 Month Fuel Cycle Evaluation Docket 8 P,CCese}Q',l n

Westinghouse Energy Systems

/

7 1

WCAP-13705 Rev.

4 WESTINGHOUSE NON-PROPRIETARY CLASS 3 WESTINGHOUSE SETPOINT METHODOLOGY FOR PROTECTION SYSTEMS DIABLO CANYON UNITS 1 AND 2 24 MONTH FUEL CYCLE EVALUATION January 1997 S.

V.

Andre'.

C.

Rood W. J. Scherder R.

W. Trozzo T.

P. Williams WESTINGHOUSE ELECTRIC CORPORATION Nuclear Services Division P. 0.

Box 355 Pittsburgh, Pennsylvania 15230-0355 e

1997 Westinghouse Electtic Corporation All Rights Reserved

0 l

FOREWORD The Westinghouse Protection System Setpoint Study provides a basis for the Reactor Protection

System, and Engineered Safety Features Actuation System values contained in the Technical Specifications.

This report contains the results associated with implementation of the Technical Specifications as well as recommended Trip Setpoints.

e

ACKNOWLEDGMENTS The authors of this report wish to acknowledge L. Bates, T. Donat, V. Backman, C. Ciocca, and P.

Kennevan for their cooperation and technical assistance throughout the Diablo Canyon Units I and 2 Extended Surveillance Interval Program.

Section TABLE OF CONTENTS Title Page

1.0 INTRODUCTION

1.1 References / Standards..

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2 2.0 COMBINATION OF UNCERTAINTY COMPONENTS......................................

3 2.1 Methodology........

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6 2.3 Rack Allowances.........

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9 2.5 Measuring and Test Equipment Accuracy 2.6 References / Standards...........

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. 10 3.0 PROTECTION SYSTEM SETPOINT METHODOLOGY.......................

12 3.1 Margin Calculation.

12 3.2 Definitions For Protection System Setpoint Tolerances...........

13 3.4 References / Standards................

23 4.0 APPLICATION OF THE SETPOINT METHODOLOGY.....................

81 4.1 Uncertainty Calculation Basic Assumptions/Premises 4.2 Sensor/Transmitter Procedural Evaluation 4.3 Process Rack Operability Determination Program and 4.4 Application to the Plant Technical Specifications 4.5 References/Standards..........

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Section LIST OF TABLES Title Page TABLE 3-1 TABLE 3-2 TABLE 3-3 TABLE 3-4 TABLE 3-5 TABLE 3-6 TABLE 3-7 TABLE 3-8 TABLE 3-9 TABLE 3-10 TABLE 3-11 TABLE 3-12 TABLE 3-13 TABLE 3-14 TABLE 3-15 TABLE 3-16 TABLE 3-17 TABLE 3-18 POWER

RANGE, NEUTRON FLUX -

LOW 5 HIGH.

POWER

RANGE, NEUTRON FLUX HIGH POSITIVE AND NEGATIVE RATE INTERMEDIATE RANGE NEUTRON FLUX.............................

SOURCE RANGE NEUTRON FLUX...

NEGATIVE STEAM PRESSURE RATE - HIGH.........................

OVERTEMPERATURE dT OVERPOWER hT PRESSURIZER PRESSURE -

LOW 5 HIGH PRESSURIZER WATER LEVEL - HIGH..............................

OSS OF FLOW

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L STEAM GENERATOR WATER LEVEL -

LOW-LOW NDERVOLTAGE U

UNDERFREQUENCY CONTAINMENT PRESSURE - HIGH, HIGH-HIGH......................

PRESSURIZER PRESSURE - SI..............

STEAMLINE PRESSURE -

LOW SI (ROSEMOUNT 1154)

STEAMLINE PRESSURE -

LOW SI (BARTON 763)....................

STEAM GENERATOR WATER LEVEL - HIGH-HIGH 26 28 30 32 33 36 38 40 42 44 46 48 50 52 54 56 58 TABLE 3-19 TABLE 3-20 TABLE 3-21 TABLE 3-22 TABLE 3-23 TABLE 3-24 TABLE 3-25 r

TABLE 3-26 TABLE 3-27 TABLE 3-28 TABLE 4.2-1 RCS LOOP bT EQUIVALENT TO POWER EISMIC

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S 4.16 KV BUS UNDERVOLTAGE (Westinghouse, 85 volts)...........

4.16 KV BUS UNDERVOLTAGE (Westinghouse, 107.8 volts)........

4.16 KV BUS UNDERVOLTAGE (General Electric, 82.45 volts)....

4. 16 KV BUS UNDERVOLTAGE (General Electric, 76.5 volts).....

60 62 64 66 68 70 OVERTEMPERATURE 6T CALCULATIONS............................

OVERPOWER 5T CALCULATIONS....................

hP MEASUREMENTS EXPRESSED IN FLOW UNITS..... -..............

SENSOR/TRANSMITTER AS-FOUND CRITERIA 75 78 79 85 REACTOR PROTECTION SYSTEM/ENGINEERED SAFETY FEATURES ACTUATION SYSTEM CHANNEL UNCERTAINTY ALLOWANCES 73 iv

1.0 INTRODUCTION

In Generic Letter 91-04, 'he NRC has noted that uncertainty calculations should be performed in a manner which results in values at a high probability and a high confidence level.

The implication of this is that a more statistically rigorous calculation is required.

In addition, Generic Letter 91-18~

clarifies the NRC's definition of operability.

In particular, Generic Letter 91-04 provides guidance on the use of statistically derived drift values based on plant specific operational data.

In response to these documents and because of the use of uncertainty values derived from actual plant data, Westinghouse has modified the basic uncertainty algorithm.

To address the requirements for a definitive basis for drift, explicit calculations were made to determine appropriate values for the transmitters/sensors.

The basic Westinghouse approach to an uncertainty calculation is to achieve an understanding of the plant instrumentation calibration and operability verification processes.

The uncertainty algorithm resulting from this understanding can be function specific, i.e., is very likely different for two functions if their calibration or operability determination processes are different.

Effort is expended in determination of what parameters are dependent statistically or functionally.

Those parameters that are determined to be independent are treated accordingly.

This allows the use of a Square-Root-Sum-Of-The-Squares (SRSS) su@nation of the various components.

A direct benefit of the use of this technique is increased margin in the total allowance.

For those parameters determined to be dependent, appropriate (conservative) su@nation techniques are utilized.

An explanation of the overall approach is provided in Section 2.0.

Section 3.0 provides a description, or definition, of each of the various components, to allow a clear understanding of the methodology.

Also provided is a detailed example of each setpoint margin calculation demonstrating the methodology and noting how each parameter value is utilized.

In all cases, margin exists between the summation and the total allowance.

Section 4.0 provides a description of the methodology utilized in the determination of the Diablo Canyon Units 1 and 2 Technical Specifications and an explanation of the relationship between a trip setpoint and an operability verification.

An Appendix is provided noting a recommended set of Technical Specifications using the plant specific data and the revised Hestinghouse approach that reflects the plant specific operability verification process.

1.1 References / Standards

[1]

Generic Letter 91-04,

1991, "Changes in Technical Specification Surveillance Intervals to Accommodate a 24 Month Fuel Cycle.

[2]

Generic Letter 91-18, 1991, "Information to Licensees Regarding Two NRC Inspection Manual Sections on Resolution of Degraded and Nonconforming Conditions and on Operability.

2.0 COMBINATION OF UNCERTAINTY COMPONENTS 2.1 Methodology The methodology used to combine the uncertainty components for a channel is an appropriate combination of those groups which are statistically and functionally independent.

Those uncertainties which are not independent are conservatively treated by arithmetic sumation and then systematically combined with the independent terms.

The basic methodology used is the SRSS technique which has been utilized in other Westinghouse reports.

This technique, or others of a similar nature, has been used in WCAP-10395 and WCAP-8567

WCAP-8567 is approved by the NRC noting acceptability of statistical techniques for the application requested.

Also, various ANSI, American Nuclear Society, and Instrument Society of America standards approve the use of probabi listic and statistical techniques in determining safety-related setpoints~'

The basic methodology used in this report is essentially the same as that noted in an ISA paper presented in 1992 '

The relationship between the uncertainty components and the calculated uncertainty for a channel is given in Eq. 2. 1, CSA

= ((PMA)

+ (PEA)

+

(SMTE +

SD)

+

(SMTE + SCA)

+ (SPE)

+

(STE)

+ (SRA)

+

(RMTE + RD)

+

(RMTE + RCA)

+

(RMTE +

RCSA)

+ (RTE)

)

+ EA + BIAS where:

CSA PMA PEA Channel Statistical Allowance Process Measurement Accuracy Primary Element Accuracy

SMTE SD SCA SPE STE SRA RMTE RD RCA RCSA RTE EA BIAS Sensor Measuring 5 Test Equipment Accuracy Sensor Drift Sensor Calibration Accuracy Sensor Pressure Effects Sensor Temperature Effects Sensor Reference Accuracy Rack Measuring 5 Test Equipment Accuracy Rack Drift Rack Calibration Accuracy Rack Comparator Setting Accuracy Rack Temperature Effects Environmental Allowance One directional, known magnitude This equation was originally designed to address analog process racks with bistables.

Digital process racks generally operate in a different manner by simulating a bistable.

The protection function setpoint is a value held in memory.

The digital process racks compare the functions value with the value stored in memory.

A trip is initiated when the function input corresponds to or exceeds the value in memory.

Thus, with the absence of a physical

bistable, the RCSA term can be eliminated.

Equation 2. 1 represents a slight variation from the equations noted in Reference 5.

In particular, it has been determined that the calibration accuracies (SCA and RCA) can be treated as random terms rather than biases.

This determination for SCA is based on evaluations which showed that the sensor As Left data can be generally characterized as having a near zero mean and a small standard deviation.

Although the Eagle 21 rack As Left data was not evaluated, it is considered to be a random term based on the self-checking feature of Eagle.

As can be seen in Equation 2. 1, drift and calibration accuracy allowances are treated as dependent parameters with the measuring and test equipment uncertainties.

The environmental allowance is not necessarily considered dependent with all other parameters, but as an additional degree of conservatism is added to the statistical sum.

Bias terms are one directional with a known magnitude and are added to the statistical sum.

The calibration

terms are treated in the same radical based'on the Generic Letter 91-04

'equirement for general trending.

Pacific Gas 8 Electric (PGEE) has indicated that trending will be performed to support the requirements of Generic Letter 91-04.

This results in a net reduction of the CSA magnitude over that which would be determined if trending was not performed.

It should be noted here that uncertainties for several Reactor Protection System channels were not recalculated by Westinghouse as part of the 24-month fuel cycle evaluation.

These channels are the Power Range Neutron Flux High and Low Setpoints, the Power Range Neutron Flux High Positive and High Negative Rates, the Intermediate Range Neutron Flux, and the Source Range Neutron Flux.

The CSA equation used for combining the uncertainty components for these channels is the same one used in Revision 2 of WCAP-11082, "Westinghouse Setpoint Methodology for Protection

Systems, Diablo Canyon Units 1 and 2, Eagle 21 Version," supporting the current Diablo Canyon Technical Specifications setpoints for those channels.

That CSA equation assumed that calibration accuracy and drift are dependent

terms, and results in a more conservative CSA than would be obtained if these channels were reevaluated with Equation

2. 1.

Although these channels were not part of the 24-month fuel cycle evaluation, they have been included in this WCAP for completeness.

The uncertainties associated with the Intermediate Range Neutron Flux and the Source Range Neutron Flux channels have been updated by PGEE.

The results in this document are based on the premise that the instrument surveillance program at Diablo Canyon Units 1 and 2 consists of a combination of quarterly rack tests and sensor/relay calibrations performed each refueling outage.

Digital Rack Drift is based on system design.

Process Measurement Accuracy terms are considered to be conservative values.

The cable PJ insulation resistance degradation

terms, the reference leg heatup uncertainty for steam generator level, and the transmitter Environmental Allowance terms for transmitters not supplied through Westinghouse were developed by PGKE.

2.2 Sensor Allowances Six parameters are considered to be sensor allowances:

SCA, SRA,

SMTE, SD,

STE, and SPE (see Table 3-25).

Of these parameters, three are considered to be independent (SRA, STE and SPE),

and three are considered dependent with at least one other term (SCA, SMTE and SD).

SRA is the manufacturer's reference accuracy that is achievable by the device.

This term is introduced to address repeatability and hysteresis concerns when only performing a single pass calibration, i.e.,

one up and one down.

STE and SPE are considered to be independent due to the manner in which the instrumentation is checked; i.e.,

the instrumentation is calibrated and drift determined under conditions in which pressure and temperature are assumed constant.

An example of this would be as follows.

Assume a sensor is placed in some position in the containment during a refueling outage.

After placement, an instrument technician calibrates the sensor.

This calibration is performed at ambient pressure and temperature conditions.

At some later plant shutdown, an instrument technician checks the sensor's performance using the same technique as for the initial calibration and from the two sets of readings a drift value can be determined.

The ambient temperature and pressure conditions should be essentially the same as those for the initial calibration.

Therefore, these conditions have no significant impact on the drift determination and are independent of the drift allowance.

The discussion about calibration at plant shutdown is for illustrative purposes only and shutdown is not a necessary condition for the data to be valid.

Any variations in the data due to changes in calibration temperature will be inherent in the drift result.

SCA, SMTE and SD are considered to be dependent for the same reason that STE and SPE are considered independent; i.e.,

due to the manner in which the instrumentation is checked.

When calibrating a sensor, the sensor output is checked to determine if it is accurately representing the input.

The sensor

response, measured by applying known inputs and recording the sensor output, involves the calibrated accuracy of both the sensor and the Measuring

& Test Equipment (M&TE).

The plant specific drift equals the difference between the "as-found" and the previous "as-left" data and therefore involves the actual sensor drift and calibration M&TE.

The "as-found calibration data indicates

whether the sensor input/output relationship was within reasonable allowances over the interval since the last calibration.

The combination of "as-left" calibration data and plant specific sensor drift indicate whether it is reasonable to expect the sensor to continue to perform this function for future cycles.

Statistically based drift values were determined for all sensors except where there was insufficient data due to recent sensor replacement.

In these

cases, a thirty (30) month drift value was determined through engineering judgment which considered manufacturer specifications, drift exhibited by devices of the same manufacturer in similar applications, and Westinghouse experience.

Drift for the following devices was not statistically based:

all Pressurizer Pressure transmitters, Containment Pressure transmitters, RCP Undervoltage relays and Steam Pressure Rosemount transmitters.

The calibration accuracy and 30 month drift values were combined with the Measuring In Test equipment accuracy term to form the dependent relationships.

A hypothetical example of the impact of this treatment for a level transmitter is (sensor parameters only):

+a,c SCA SRA SMTE SPE STE SD excerpting the sensor portion of Equation 2.1 results in;

{(SMTE + SCA)

+

(SMTE + SD)

+ (SPE)

+

(STE)

+ (SRA)

)

Assuming no dependencies for any of the parameters results in the following:

{(SCA)

+

(SMTE)

+ (SD)

+ (SPE)

+ (STE)

+

(SRA) )

-or-(Eq. 2.2)

] " = 1.5%

Thus it can be seen that the approach represented by Equation 2. 1, which accounts for dependent parameters, results in a more conservative summation of the allowances.'.3 Rack Allowances Five parameters, as noted by Table 3-25, are considered to be rack allowances:

RCA, RMTE, RCSA,

RTE, and RD.

Three of these parameters (RCA, RMTE, and RD) are considered to be dependent for much the same reason outlined for sensors in Section 2.2.

As noted in Section 2. 1, the rack comparator setting accuracy (RCSA) may be eliminated for digital channels.

When calibrating or determining drift in the racks for a specific channel, the processes are performed at essentially constant temperature; i.e.,

ambient temperature (which is reasonably controlled).

Because of this, the RTE parameter is considered to be independent of any factors for calibration or drift.

However, the same cannot be said for the other rack parameters.

As noted in Section 2.2, when calibrating or determining drift for a channel, the same end result is desired; that is, the point at which the bistable changes state.

Based on this logic, these factors have been conservatively sumaed to form several independent groupings (see Equation 2. 1).

The impact of this approach (formation of independent groups based on dependent components) is significant.

For the hypothetical example of an analog

channel, using the same approach outlined in Equations

2. 1 and 2.2 results in the following:

+a,c RCA RMTE RCSA RTE RD

excerpting the rack portion of Equation 2.1 results in:

{(RMTE + RCA)

+

(RMTE + RCSA)

+(RMTE + RD)

+ (RTE) }

j '15%

Assuming no dependencies for any of the parameters yields the following less conservative results:

{(RCA)

+

(RMTE)

+

(RCSA)

+

(RD)

+ (RTE) }

(Eq. 2.3)

-or-j " = 1.3%

Thus, the use of Equation 2.1 is conservative for rack effects and for sensor effects.

Therefore, accounting for dependencies in the treatment of these allowances provides a conservative result.

Similar results, with different magnitudes, would be arrived at using digital process rack uncertainties.

2.4 Process Allowances Finally, the PMA and PEA parameters are considered to be independent of both sensor and rack parameters.

PMA provides allowances for the non-instrument related effects; e.g.,

neutron flux, calorimetric power uncertainty assumptions, fluid density changes, and temperature stratification assumptions.

PMA may consist of more than one independent uncertainty allowance.

PEA accounts for uncertainties due to metering devices, such as elbows, venturis, and orifice plates.

Thus, these parameters have been factored into Equation 2. 1 as independent quantities.

It should be noted that treatment as an independent parameter does not preclude determination that a

PMA or PEA term should be treated as a bias.

If that is determined to be appropriate, Equation 2. 1 would be modified such that the affected term would be treated by arithmetic sumation as deemed necessary.

2.5 Measuring and Test Equipment Accuracy Based on information from PGImE, it was concluded that the test equipment used for calibration of the transmitters does not meet ISA S51. 1-1979 with regards to allowed exclusion from the calculation.

This implies that test equipment without an accuracy of 10K or less of the calibration accuracy is required to be included in the uncertainty calculations of Equations

2. 1 and

3. 1.

Information from PGEE indicated that the rack measuring and test equipment (Eagle 21 only) does meet the ISA standard, and therefore the RMTE terms are taken to be zero.

The Sensor Measuring Im Test Equipment (SMTE) accuracies used in this study represent the maximum allowed inaccuracy of the test equipment.

2.6 References / Standards LQ L3j 14j L57 Grigsby, J.

M., Spier, E. M., Tuley, C. R., "Statistical Evaluation of LOCA Heat Source Uncertainty,"

WCAP-10395 (Proprietary),

WCAP-10396 (Non-Propri etary),

November 1983.

Chelemer, H.,

Boman, L. H., and Sharp, D. R., "Improved Thermal Design Procedure,"

WCAP-8567 (Proprietary),

WCAP-8568 (Non-Proprietary), July, 1975.

ANSI/ANS Standard 58.4-1979, "Criteria for Technical Specifications for Nuclear Power Stations."

ISA Standard S67.04, 1994, "Setpoints for Nuclear Safety-Related Instrumentation Used in Nuclear Power Plants."

Tuley, C. R., Williams, T. P.,

"The Significance of Verifying the SAMA PMC 20. 1-1973 Defined Reference Accuracy for the Westinghouse Setpoint Methodology," Instrumentation, Controls and Automation in the Power Industry, Vol. 35, Proceedings of the Thirty-Fifth Power Instrumentation Symposium (2"

Annual ISA/EPRI Joint Controls and Automation Conference),

Kansas City, Mo., June,

1992,

p. 497.

Generic Letter 91-04,

1991, "Changes in Technical Specification Surveillance Intervals to Accommodate a 24 Month Fuel Cycle."

10

Westinghouse Letter to

PGSE, PGE-96-569, J.

Hoebel to S.D.

Kamdar, 6/14/96.

Instrument Society of America Standard S51. 1-1979 (Reaffirmed 1993),

"Process Instrumentation Terminology."

11

3.0 PROTECTION SYSTEM SETPOINT METHODOLOGY 3.1 Margin Calculation As noted in Section 2.0, Westinghouse utilizes the square root of the sum of the squares for summation of the various components of the channel uncertainty.

This approach is valid where no dependency is present.

Arithmetic summation is a conservative treatment when a dependency between two or more parameters exists.

The equation used to determine the margin, and thus the acceptability of the parameter values used, is:

Margin

=

TA - ((PHA)

+

(PEA)

+ (SMTE+ SCA)

+ (SMTE+ SD)

+

(SPE)

+ (STE)

+ (SRA)

+

(RHTE + RCA)

+

(RMTE +

RCSA)

+ (RHTE + RD)

+ (RTE)

)

EA - BIAS where:

TA Total Allowance, which is defined as (Safety Analysis Limit - Nominal Trip Setpoint) and all other parameters are as defined for Equation 2.1.

This equation is appropriate when trending of transmitter calibration and drift is taking place.

Using Equation

2. 1, Equation 3. 1 may be simplified to:

Margin

=

TA -

CSA For those channels which were not evaluated for the 24-month fuel cycle

program, Equation 3.2 may still be used for determining margin.

The value for CSA to be used in Equation 3.2 would be based on the CSA equation which was used for that particular channel.

Determination of margin and Total Allowance is appropriate only for those channels which have an explicit Safety Analysis Limit (or other licensing basis limit).

12

Tables 3-1 through 3-24 provide individual component uncertainties and CSA calculations for the protection functions noted in Tables 2.2-1 and 3.3-4 of the Diablo Canyon Units 1 and 2 Technical Specifications.

Table 3-25 provides a summary of the Reactor Protection System / Engineered Safety Features Actuation System Channel Uncertainty Allowances for Diablo Canyon Units 1 and 2 and includes Safety Analysis and Technical Specification values, Total Allowance and Margin.

The values in these tables are reported to two decimal places using the conventional technique of rounding down numbers less than 5

and rounding up numbers greater than or equal to 5.

Parameters reported in the tables as "N/A", "0", or "---" are not applicable or have no value for that channel.

3.2 Definitions For Protection System Setpoint Tolerances To insure a clear understanding of the channel uncertainty values used in this report, the following definitions are provided.

For terms which are not defined in this section, refer to ISA S67.04 Analog-to-Digital (A/D)

An electronic circuit module used to convert a continuously variable analog signal to a discrete digital signal via a prescriptive algorithm.

Allowable Value A bistable trip setpoint (analog function) or CPU trip output (digital function) in plant Technical Specifications, which allows for deviation, e.g.,

Rack Drift plus Rack Measuring 5 Test Equipment Accuracy, from the Nominal Trip Setpoint.

A trip setpoint found non-conservative with respect to the Allowable Value requires some action for restoration by plant operating personnel.

13

+

As Found The condition in which a transmitter, process rack module or process instrument loop is found after a period of operation.

For example, after a period of operation, a transmitter was found to deviate from the ideal condition by -0.5% span.

This would be the "as found" condition.

+

As Left The condition in which a transmitter, process rack module or process instrument loop is left after calibration or bistable trip setpoint verification.

This condition is typically better than the calibration accuracy for that piece of equipment.

For example, the permitted calibration accuracy for a transmitter is t0.5% of span, while the worst measured deviation from the ideal condition after calibration is +0.1%

span.

In this instance, if the calibration was stopped at this point (i.e.,

no additional efforts were made to decrease the deviation) the "as left" error would be +0. 1% span.

+

Channel The sensing and process equipment, i.e., transmitter to bistable (analog function) or transmitter to CPU trip output (digital function), for one input to the voting logic of a protection function.

Westinghouse designs protection functions with voting logic made up of multiple

channels, e.g.

2/3 Steam Generator Level - Low-Low channels per one steam generator must have their bistables in the tripped condition for a Reactor Trip to be initiated.

+

Channel Statistical Allowance (CSA)

The combination of the various channel uncertainties via SRSS and arithmetic summation, as appropriate.

It includes both instrument (sensor and process rack) uncertainties and non-instrument related 14

effects (Process Measurement Accuracy).

This parameter is compared with the Total Allowance for determination of instrument channel margin.

+

Environmental Allowance (EA)

The change in a process signal (transmitter or process rack output) due to adverse environmental conditions from a limiting accident condition.

Typically this value is determined from a conservative set of enveloping conditions and may represent the following:

a) temperature effects on a transmitter, b) radiation effects on a transmitter, c) seismic effects on a transmitter, d) temperature effects on a level transmitter reference leg, e) temperature effects on signal cable insulation, and f) seismic effects on process racks.

+

Margin The calculated difference between the Total Allowance and the Channel Statistical Allowance.

+

Nominal Trip Setpoint (NTS)

A bistable trip setpoint (analog function) or CPU trip output (digital function) in plant Technical Specifications or plant administrative procedures.

This value is the nominal value to which the bistable is

set, as accurately as reasonably achievable (analog function) or the defined input value for the CPU trip output setpoint (digital function).

+

Normalization The process of establishing a relationship, or link, between a process parameter and an instrument channel.

This is in contrast with a calibration process.

A calibration process is performed with 15

independent known values, i.e.,

a bistable is calibrated to change state when a specific voltage is reached.

This voltage corresponds to a process parameter magnitude with the relationship established through the scaling process.

A normalization process typically involves an indirect measurement, e.g.,

determination of Steam Flow via the hp drop across a flow restrictor.

The flow coefficient is not known for the restrictor, effectively an orifice, therefore a mass balance between Feedwater Flow and Steam Flow must be made.

With the Feedwater Flow known through measurement via the venturi, the Steam Flow is normalized.

Primary Element Accuracy (PEA)

Uncertainty due to the use of a metering device, e.g., venturi, orifice, or elbow.

Typically, this is a calculated or measured accuracy for the device.

Process Loop (Instrument Process Loop)

The process equipment for a single channel of a protection function.

Process Measurement Accuracy (PMA)

Allowance for non-instrument related effects which have a direct bearing on the accuracy of an instrument channel's reading, e.g.,

temperature stratification in a large diameter pipe, fluid density in a pipe or vessel.

Process Racks The analog or digital modules downstream of the transmitter or sensing

device, which condition a signal and act upon it prior to input to a voting logic system.

For Westinghouse process

systems, this includes all the equipment contained in the process equipment cabinets, e.g.,

conversion resistor, transmitter power supply, R/E, lead/lag,

rate, lag functions, function generator,

summator, control/protection isolator, 16

and bistable for analog functions; conversion resistor, transmitter power supply, signal conditioning-A/0 converter and CPU for digital functions.

The go/no go signal generated by the bistable is the output of the last module in the analog process rack instrument loop and is the input to the voting logic.

For a digital system, the CPU trip output signal is the input to the voting logic.

+

R/E Resistance (R) to voltage (E) conversion module.

The RTD output (change in resistance as a function of temperature) is converted to a process loop working parameter (voltage) by this analog module.

Westinghouse Eagle-21 Process Instrumentation System utilizes R/E converters for treatment of RTD output signals.

Rack Calibration Accuracy (RCA)

The reference (calibration)

accuracy, or accuracy rating as defined by ISA Standard S51.1-1979, for a process loop string.

Inherent in this definition is the verification of the following under a reference set of conditions;

1) conformity, 2) hysteresis 'nd 3) repeatability The Westinghouse definition of a process loop includes all modules in a specific channel.

Also it is assumed that the individual modules are calibrated to a particular tolerance and that the process loop as a

string is verified to be calibrated to a specific tolerance.

The tolerance for the string is typically less than the arithmetic sum or SRSS of the individual module tolerances.

This forces calibration of the process loop without a systematic bias in the individual module calibrations, i.e.,

as left values for individual modules must be compensating in sign and magnitude.

For a Westinghouse supplied digital channel, RCA represents calibration of the signal conditioning - A/D converter providing input to the CPU.

Typically there is only one module present in the digital process

loop, thus compensation between multiple modules for errors is not possible.

17

However, for protection functions with multiple inputs, compensation between multiple modules for errors is possible.

Each signal conditioning - A/D converter module is calibrated to within an accuracy of [

]"'or functions with process rack inputs of 4 - 20 mA or10-50mA, or [

] " for RTD inputs.

Rack Comparator Setting Accuracy (RCSA)

The reference (calibration) accuracy, or accuracy rating as defined by ISA Standard S51. 1-1979

, of the instrument loop comparator (bistable).

Inherent in this definition is the verification of repeatabi lity'nder a reference set of conditions.

For a single input bistable (fixed setpoint) the typical calibration tolerance is

] ".

This assumes that comparator nonlinearities are compensated by the setpoint.

For a dual input bistable (floating setpoint) the typical calibration tolerance is [

] ".

This allows for nonlinearities between the two inputs.

In many plants calibration of the bistable is included as an integral part of the rack calibration, i.e., string calibration.

Westinghouse supplied digital channels do not have an electronic comparator, therefore no uncertainty is included for this term for these channels.

Rack Drift (RD)

The change in input-output relationship over a period of time at reference conditions.

Typical values assumed for this parameter are

~l.OX span for analog channels and [

]"'or di gital channels.

An example of RD is: for an "as found" value of -0.5% span and an "as left" value of +0. 1% span, the magnitude of the drift would be {(-0.5) - (+0. 1)

= -0.6X span) in the negative direction.

Rack Measuring E Test Equipment Accuracy (RMTE)

The accuracy of the test equipment (typically a transmitter simulator, voltage or current power supply, and DVM) used to calibrate a process 18

loop in the racks.

When the magnitude of RMTE meets the requirements of by ISA Standard S51.1-1979 it is considered an integral part of RCA.

Magnitudes in excess of the 10: 1 limit are explicitly included in Westinghouse calculations.

+

Rack Temperature Effects (RTE)

Change in input-output relationship for the process rack module string due to a change in the ambient environmental conditions (temperature, humidity, voltage and frequency) from the reference calibration conditions.

It has been determined that temperature is the most significant, with the other parameters being second order effects.

For Westinghouse supplied process instrumentation, a value of

]"'s used for analog channel temperature effects and L

]"'s used for digital channels.

It is assumed that calibration is performed at a nominal ambient temperature of +70'F.

Safety Analysis Limit (SAL)

The parameter value assumed in a transient analysis or other plant operating limit at which a reactor trip or actuation function i s initiated.

Sensor Calibration Accuracy (SCA)

The calibration accuracy for a Sensor or transmitter as defined by the Diablo Canyon Units 1 and 2 calibration procedures.

For transmitters, this accuracy is typically ~0.5% span as defined by PGLE Procedures.

Utilizing Westinghouse recommendations for RTD cross-calibration, this accuracy is typically [

] " for the Hot and Cold Leg RTDs.

Sensor Drift (SD)

The change in input-output relationship over a period of time at reference calibration conditions.

An example of SD is: for an "as 19

found" value of +0.5% span and an "as left" value of +0.1% span, the magnitude of the drift would be ((+0.5) -(+0.1)

= +0.4% span) in the positive direction.

For this evaluation, a maximum surveillance interval of 30 months was assumed when projecting drift allowance.

+

Sensor Measuring E Test Equipment Accuracy (SMTE)

The accuracy of the test equipment (typically a high accuracy local readout gauge and DYM) used to calibrate a sensor or transmitter in the field or in a calibration laboratory.

When the magnitude of SMTE meets the requirements of by ISA Standard S51. 1-1979't is considered an integral part of SCA.

Magnitudes in excess of the 10:1 limit are explicitly included in Westinghouse calculations.

Sensor Pressure Effects (SPE)

The change in input-output relationship due to a change in the static head pressure from the calibration conditions or the accuracy to which a correction factor is introduced for the difference between calibration and operating conditions for a dp transmitter.

Sensor Temperature Effects (STE)

The change in input-output relationship due to a change in the ambient environmental conditions (temperature, humidity, voltage and frequency) from the reference calibration conditions.

It has been determined that temperature is the most significant, with the other parameters being second order effects.

It is assumed that calibration is performed at a

nominal ambient temperature of +70 F.

Sensor Reference Accuracy The reference accuracy that is achievable by the device as specified in the manufacturers specification sheets.

Reference (calibration) accuracy or accuracy rating for a sensor'r transmitter as defined by 20

ISA Standard S51.1-1979 l.

Inherent in this definition is the verification of the following under a reference set of conditions; 1) conformity, 2) hysteresis and 3) repeatability This term is introduced into the uncertainty calculation to address repeatability concerns when only performing a single pass calibration (i.e.,

one up and one down), or repeatability and hysteresis when performing a single pass calibration in only one direction.

+

Span The region for which a device is calibrated and verified to be operable, e.g., for a Pressurizer Pressure transmitter with a calibrated range of 1250 - 2500 psig would yield a span of 1250 psig.

For Pressurizer

Pressure, considerable suppression of the zero and turndown of the operating range is exhibited.

+

SRSS Square root of the sum of the squares, i.e.,

as approved for use in setpoint calculations by ISA Standard S67.04-1994

+

Total Allowance (TA)

The absolute value of the calculated difference between the Safety Analysis Limit and the Nominal Trip Setpoint l(SAL - NTS)

I in X

instrument span.

Two examples of the calculation of TA are:

21

~

NIS Power Ran e Neutron Flux - Hi h SAL 118%

RTP NTS 109K RTP TA 9X RTP If the instrument span

= 120Ã RTP, then TA = (9X RTP)(100K span)/(120'L RTP)

= 7.5X span Pressurizer Pressure - Low Tri SAL 1845 psi9 NTS

-~1950 s i TA I -105 psi I= 105 psi If the instrument span

= 1250 psi, then TA = (105 psi)(100K span)/(1250 psi)

= 8.4K span 22

3.3 References / Standards L2j pj L6j Instrument Society of America Standard S51. 1-1979 (Reaffirmed 1993),

"Process Instrumentation Terminology",

p 6.

Ibid, p 8.

Ibid, p 20.

Ibid, p 27.

Ibid, p 32.

Instrument Society of America Standard S67.04-1994, "Setpoints for Nuclear Safety-Related Instrumentation",

p 18, 1994.

23

TABLE 3-1 POWER

RANGE, NEUTRON FLUX - HIGH AND LOW SETPOINTS**

Parameter Process Measurement Accuracy

+a,c Allowance*

+a,c Primary Element Accuracy Sensor Calibration j+a,c Sensor Pressure Effects Sensor Temperature Effects j+a,c Sensor Drift j+a,c Environmental Allowance Rack Calibration Rack Measuring 8 Test Equipment Accuracy Comparator One input Rack Temperature Effects Rack Drift In percent span (120% Rated Thermal Power)

• • Not processed by Eagle-21 racks.

TABLE 3-1 (continued)

POWER RANGE, NEUTRON FLUX - HIGH AND LOW SETPOINTS Channel Statistical Allowance =

((PHA)

+ (PEA)

+

(SCA +

SD)

+ (SPE)

+ (STE)

+

(RCA + RHTE + RCSA + RD)

+ (RTE) )

+

EA + BIAS 25

TABLE 3-2 POMER

RANGE, NEUTRON FLUX - HIGH POSITIVE RATE AND HIGH NEGATIVE RATE**

Parameter Process Measurement Accuracy

+a,c Al1 owance*

+8,C Primary Element Accuracy

+i!,C Sensor Pressure Effects Environmental Allowance Rack Calibration Rack Measuring

& Test Equipment Accuracy Comparator One input Rack Temperature Effects Rack Drift In percent span (120% Rated Thermal Power)

• Not processed by Eagle-21 racks.

26

TABLE 3-2 (continued)

POWER

RANGE, NEUTRON FLUX - HIGH POSITIVE RATE AND HIGH NEGATIVE RATE

• Channel Statistical Allowance =

((PMA)

+

(PEA)

+

(SCA +

SD)

+

(SPE)

+

(STE)

+

(RCA + RMTE + RCSA + RD)

+ (RTE) )

+

EA + BIAS 27

TABLE 3-3 INTERMEDIATE RANGE, NEUTRON FLUX**

Par ameter Process Measurement Accuracy

+a,c Allowance*

+a,c Primary Element Accuracy Sensor Calibration

]+a>

c Sensor Pressure Effects Sensor Temperature Effects

]+a>c Sensor Orift Environmental Allowance Rack Calibration Rack Measuring 8 Test Equipment Accuracy Comparator One input Rack Temperature Effects Rack Drift j+a,c In percent span (conservatively assumed to be 120% Rated Thermal Power)

• • Not processed by Eagle-21 racks.

28

TABLE 3-3 (continued)

INTERMEDIATE RANGE, NEUTRON FLUX**

Channel Statistical Allowance =

{(PMA)

+

(PEA)

+

(SCA +

SD)

+ (SPE)

+ (STE)

+

(RCA + RMTE + RCSA + RD)

+

(RTE)

)

+

EA + BIAS

+a,c 29

TABLE 3-4 SOURCE

RANGE, NEUTRON FLUX*

Parameter Process Measurement Accuracy

+a,c Al1 owance*

+a,c Primary Element Accuracy Sensor Calibration j+a,c Sensor Pressure Effects Sensor Temperature Effects j+a,c Sensor Drift Environmental Al 1 owance Rack Calibration Rack Measuring 8 Test Equipment Accuracy Comparator One input Rack Temperature Effects Rack Drift 3 x 10 cps In X span (I x 10 cps)

• • Not processed by Eagle-21 racks.

30

TABLE 3-4 (continued)

SOURCE

RANGE, NEUTRON FLUX

• Channel Statistical Allowance =

{(PMA)

+ (PEA)

+

(SCA +

SD)

+

(SPE)

+ (STE)

+

(RCA + RMTE + RCSA + RD)

+ (RTE) )

+

EA + BIAS 31

TABLE 3-5 NEGATIVE STEAMLINE PRESSURE RATE - HIGH Parameter Process Measurement Accuracy Primary Element Accuracy Allowance*

+a,c Sensor Pressure Effects Sensor Temperature Effects

+a,c Environmental Allowance Rack Calibration Rack Measuring

& Test Equipment Rack Temperature Effects Rack Drift In X span (1200 psi)

Channel Stat, istical Allowance =

((PMA)

+ (PEA)

+

(SCA + SMTE) +

(SMTE + SD)

+ (SPE)

+ (STE)

-+

(RCA + RMTE) +

(RMTE + RD)

+ (RTE)

}

+ EA + BIAS

+a,c 32

TABLE 3-6 OVERTEMPERATURE hT Parameter Process Measurement Accuracy

]+a,c

]+a,c

]+a>c

]+a,c

]+a,c

]+a,c

]+a,c

]+a,c Allowance*

+a,c Primary Element Accuracy Sensor Calibration Accuracy

]+a,c

]ia,c Sensor Reference Accuracy

]+a,c

]+a,c Sensor Measuring 5 Test Equipment Accuracy

]+a,c

]+a,c Sensor Pressure Effects Sensor Temperature Effects

]+a,c Sensor Drift

]+a,c

]+a,c Environmental Allowance 33

TABLE 3-6 (continued)

OVERTEMPERATURE AT Parameter Rack Calibration Accuracy Allowance*

+a,c j+a,c j+a,c Rack Measuring

& Test Equipment Accuracy L

j+a,c j+a,c

]+a>c Rack Temperature Effect j+a,c j+a,c

~+a,c Rack Drift L

L j+a,c j+a,c j+a,c In percent dT span (dT - 96.6'F - Unit 1 (this is bounding for the Unit 1

uprated value of 98.6'F); 97.5'F - Unit 2)

NH = 8 of hot leg RTDs

= 2 Nq = 8 of cold leg RTDs

=

1 34

TABLE 3-6 (continued)

OVERTEMPERATURE hT Channel Statistical Allowance =

t,(PMA)

+

(PEA)

+

E(~SMTE r~+SD rX ~+SMTE r~+SCA rl

+

NH

~SMTE r~+SD rl ~+SMTE r~+SCA rl

)

2

+

Nc

({~RMTE r~+RD r$ ~+RTE rg ~+RMTE r~+RCA rj

+

NH

~RMTE r~+RD rg~+RTE J ~+RMTE r~+RCA J

} j

+

Nc (SMTEp +

SDp)

+

(SRAp)

+

(SPEp)

+

(STEp)

+

(SMTEp + SCAp)

+

(RMTEp + RDp)

+ (RTEp)

+

(RMTEp + RCAp) 2(RMTEzl + RDAji)

+ 2(RTEng)

+ 2(RMTEgl + RCAzl) )

+

EA + BIAS 35

TABLE 3-7 OVERPOWER AT Parameter Process Measurement Accuracy

]+a,c

]+a,c

]+a,c

]+a,c

]+a,c

]+a,c Al1 owance*

+a,c Primary Element Accuracy Sensor Calibration Accuracy

]+a,c Sensor Reference Accuracy

]+a,c Sensor Measuring

& Test Equipment Accuracy

]+a>c Sensor Pressure Effects Sensor Temperature Effects Sensor Drift

]+a,c Environmental Al 1 owance AT - Cable IR Effects (+I'F)

Tavg - Cable IR Effects (+8'F)

Rack Calibration Accuracy

]+a,c Rack Measuring 5 Test Equipment Accuracy

]+a,c 36

Parameter Rack Temperature Effect TABLE 3-7 (continued)

OVERPOWER hT j+a,c Allowance*

+a,c Rack Drift j+a,c In percent hT span (bT - 96.6 F - Unit 1 (this is bounding for the Unit 1

uprated value of 98.6'F); 97.5'F - Unit 2)

NH = ¹ of hot leg RTDs

= 2 N< = ¹ of cold leg RTDs

=

1 Channel Statistical Allowance =

((PMA)

+

(PEA)

+

l{~SMTE r~+SD r):~+SMTE r~+SCA r): +

NH

~SMTE r~+SD r) ~+SMTE r~+SCA rg }g-+

Nc l(~RMTE r~+RO r)~~+RTE rl ~+RMTE r~+RCA r)

+

NH

~RMTE r~+RD r);~+RTE rg ~+RMTE r~+RCA rj

)"j )" -+

Nc EA + BIAS

+a,c 37

TABLE 3-8 PRESSURIZER PRESSURE -

LOW AND HIGH REACTOR TRIP Parameter Process Measurement Accuracy Primary Element Accuracy Sensor Calibration Accuracy Sensor Reference Accuracy Sensor Measuring

& Test Equipment Accuracy Sensor Pressure Effects Sensor Temperature Effects.

Sensor Drift (30 months)

Environmental Allowance Rack Calibration Accuracy Rack Measuring

& Test Equipment Accuracy Rack Temperature Effect Rack Drift Allowance

+a,c

• In percent span (1250 psi) 38

TABLE 3-8 (continued)

PRESSURIZER PRESSURE -

LOW AND HIGH REACTOR TRIP Channel Statistical Allowance =

f(WA)'

(PEA)'

(SHTE +

SO)'

(SRA)'

(SPE)'

(STE)'

(SMTE + SCA)

+ (RHTE+ RO)

+ (RTE)

+

(RNITE + RCA) )

+ EA + BIAS 39

TABLE 3-9 PRESSURIZER WATER LEVEL - HIGH Parameter Process Measurement Accuracy j+a,c j+a,c j+a,c Allowance*

+a,c Primary Element Accuracy Sensor Calibration Accuracy Sensor Reference Accuracy Sensor Measuring 5 Test Equipment Accuracy Sensor Pressure Effects Sensor Temperature Effects Sensor Drift/Process Effects (30 months)**

Environmental Allowance Rack Calibration Accuracy Rack Measuring 8 Test Equipment Accuracy Rack Temperature Effect Rack Drift In percent span (100K)

• • A drift allowance of t5.0% has been calculated based on the Pressurizer Level as-found and as-left data.

Since Rosemount transmitter drift is typically in the range of i0.6% to +1.2%, it is the joint PGKE and Westinghouse engineering judgment that the a5l drift is caused by installation/configuration effects associated with the DP level measurement

system, as well as the transmitter.

As long as the as-found and as-left data reflects both the process effects and transmitter drift, the 5X process/transmitter drift allowance may be used to verify continued performance consistent with historical data.

40

TABLE 3-9 (continued)

PRESSURIZER MATER LEVEL - HIGH Channel Statistical Allowance =

((PMA)'+ (PEA)'+ (SMTE+

SO)'+ (SRA)'+ (SPE)'+ (STE)'+

(SMTE + SCA)

+ (RTE)

+

(RMTE + RD)

+

(RMTE + RCA) )

+ EA + BIAS

TABLE 3-10 LOSS OF FLOW Parameter Process Measurement Accuracy

+a,c Allowance

+a,c Primary Element Accuracy j+a,c Sensor Calibration j+a,c Sensor Reference Accuracy j+a,c Sensor Measuring 5 Test Equipment Accuracy j+a,c Sensor Pressure Effects j+a,c Sensor Temperature Effects j+a,c Sensor Drift j+a,c Bias j+a,c Rack Calibration j

<a,c Rack Measuring 8 Test Equipment Accuracy Rack Temperature Effects

]+a,c Rack Drift j+a,c

• In I flow span (120.0% Thermal Design Flow). Percent dP span converted to flow span via Equation 3-28.8, with F= 120.0X and F= 90K

TABLE 3-10 (continued)

LOSS OF FLOW Channel Statistical Allowance

=

{(PMA)

+ (PEA)

+

(SMTE +

SD)

+ (SRA)

+ (SPE)

+ (STE)

+

(SCA)

+ (RTE)

+ (RMTE + RD)

+

(RHTE + RCA) }

+ EA + BIAS

TABLE 3-11 STEAM GENERATOR NARROW RANGE WATER LEVEL -.LOW-LOW Parameter Process Measurement Accuracy

[

L L

j+a,c j+a,c j+a,c j+a,c A11owance*

+a,c Primary Element Accuracy Sensor Calibration Accuracy Sensor Reference Accuracy Sensor Measuring E Test Equipment Accuracy Sensor Pressure Effects Sensor Temperature Effects Sensor Drift (30 months)

Environmental Allowance Transmitter Elevated Temperature Effects Reference Leg Heatup Cable IR Effects Rack Calibration Accuracy Rack Measuring 5 Test Equipment Accuracy Rack Temperature Effect Rack Drift

• In percent span (100%)

TABLE 3-11 (continued)

STEAM GENERATOR NARROM RANGE MATER LEVEL "- LOW-LOW Channel Statistical Allowance =

f (PMA)

+ (PEA)

+

(SMTE +

SD)

+ (SRA)

+. (SPE)

+ (STE)

+

(SMTE + SCA)

+

(RMTE + RD)

+ (RTE)

+

(RMTE + RCA) )

+

EA + BIAS 45

TABLE 3-12 REACTOR COOLANT PUMP UNDERVOLTAGE**

BASLER BEI-27 RELAY Parameter Process Measurement Accuracy Primary Element Accuracy Sensor Calibration Accuracy Sensor Reference Accuracy Sensor Measuring E Test Equipment Accuracy Sensor Pressure Effects Sensor Temperature Effects Sensor Drift (30 months)

Environmental Allowance Rack Calibration Accuracy Rack Measuring 8 Test Equipment Accuracy Rack Temperature Effect Rack Drift Allowance

+ih, C In Volts

• • Not processed by Eagle-21 racks.

46

TABLE 3-12 (continued)

REACTOR COOLANT PUMP UNDERVOLTAGE*

BASLER BE1-27 RELAY Channel Statistical Allowance =

((PMA)

+

(PEA)

+

(SHTE +

SD)

+

(SRA)

+ (SPE)

+ (STE)

+

(SHTE + SCA)

+

(RMTE + RD)

+

(RTE)

+

(RHTE + RCA) )

+

EA + BIAS

TABLE 3-13 REACTOR COOLANT PUMP UNDERFREQUENCY*

BASLER BE1-81 0/U RELAY Parameter Process Measurement Accuracy Primary Element Accuracy Sensor Calibration Accuracy Sensor Reference Accuracy Sensor Measuring Im Test Equipment Accuracy Sensor Pressure Effects Sensor Temperature Effects***

Sensor Drift (30 months)

Environmental Al 1 owance Rack Calibration Accuracy Rack Measuring 5 Test Equipment Accuracy Rack Temperature Effect Rack Drift Allowance*

+ a,c In Hertz Not processed by Eagle-21 racks.

Based on engineering

judgment, not specified by Vendor.

48

TABLE 3-13 (continued)

REACTOR COOLANT PUMP UNDERFREgUENCY**

BASLER BE1-81 0/U RELAY Channel Statistical Allowance =

t (PMA)

+ (PEA)

+

(SMTE +

SO)

+

(SRA)

+ (SPE)

+ (STE)

+

(SMTE + SCA)

+

(RMTE + RD)

+ (RTE)

+

(RMTE + RCA) )

+

EA + BIAS 49

TABLE 3-14 CONTAINMENT PRESSURE - HIGH, HIGH-HIGH Parameter Process Measurement Accuracy Primary Element Accuracy Sensor Calibration Accuracy Sensor Reference Accuracy Sensor Measuring 5 Test Equipment Accuracy Allowance*

ta,c Sensor Pressure Effects Sensor Temperature Effects Sensor Drift (30 months)

Environmental Allowance Rack Calibration Accuracy Rack Measuring E Test Equipment Accuracy Rack Temperature Effect Rack Drift In percent span (60 psi) 50

TABLE 3-14 (continued)

CONTAINMENT PRESSURE - HIGH, HIGH-HIGH Channel Statistical Allowance =

{(PMA)

+

(PEA)

+

(SMTE +

SD)

+ (SRA)

+ (SPE)

+ (STE)

+

(SMTE + SCA)

+

(RMTE + RD)

+ (RTE)

+

(RMTE + RCA) )

+

EA + BIAS 51

TABLE 3-15 PRESSURIZER PRESSURE -

LOW, SAFETY INJECTION Parameter Process measurement Accuracy Primary Element Accuracy Sensor Calibration Accuracy Sensor Reference Accuracy Sensor Measuring 5 Test Equipment Accuracy Sensor Pressure Effects Sensor Temperature Effects Sensor Drift (30 months)

Allowance*

+a,c Environmental Allowance Transmitter Effects Cable IR Effects Rack Calibration Accuracy Rack Neasuring 5 Test Equipment Accuracy Rack Temperature Effect Rack Drift

• In percent span (1250 psi) 52

TABLE 3-15 (continued)

PRESSURIZER PRESSURE -

LOW, SAFETY INJECTION Channel Statistical Allowance =

f (PMA)

+ (PEA)

+

(SMTE +

SD)

+ (SRA)

+

(SPE)

+ (STE)

+

(SMTE + SCA)

+

(RMTE + RD)

+ (RTE)

+

(RMTE + RCA) }

+

EA + BIAS 53

TABLE 3-16 STEAM LINE PRESSURE -

LOW ROSEMOUNT 1154 TRANSMITTER Parameter Process Measurement Accuracy Primary Element Accuracy Sensor Calibration Accuracy Sensor Reference Accuracy Sensor Measuring E Test Equipment Accuracy Sensor Pressure Effects Sensor Temperature Effects Sensor Drift (30 months)

Allowance*

+a,c Environmental Al 1 owance Transmitter Effects (R1154SH9 Temp and Pressure effect)

Cable IR Effects Rack Calibration Accuracy Rack Measuring 5 Test Equipment Accuracy Rack Temperature Effect Rack Drift Tag No.'s - P515 (Unit 1),

P524 (Unit 1),

P545 (Unit 2)

In percent span (1200 psi)

TABLE 3-16 (continued)

STEAM LINE PRESSURE -

LOM ROSEMOUNT 1154 TRANSMITTER Channel Statistical Allowance

=

((PMA)

+

(PEA)

+

(SMTE +

SD)'+ (SRA)'+ (SPE)'+ (STE)'+

(SMTE + SCA)

+

(RMTE + RD)

+ (RTE)

+ (RMTE + RCA) )

+

EA + BIAS 55

Parameter TABLE 3-17 STEAM LINE PRESSURE -

LOW BARTON 763 TRANSMITTER Allowance*

Process Measurement Accuracy Primary Element Accuracy Sensor Calibration Accuracy Sensor Reference Accuracy Sensor Measuring E Test Equipment Accuracy Sensor Pressure Effects Sensor Temperature Effects Sensor Drift (30 months)

Environmental Allowance Transmitter Elevated Temperature Effects Cable IR Effects Rack Calibration Accuracy Rack Measuring 8 Test Equipment Accuracy Rack Temperature Effect Rack Drift Tag No.'s - P514, P515 (Unit 2),

P516, P524 (Unit 2),

P525, P526,

P534, P535,

P536, P544, P545 (Unit 1),

P546, In percent span (1200 psi) 56

TABLE 3-17 (continued)

STEAM LINE PRESSURE -

LOW BARTON 763 TRANSMITTER Channel Statistical Allowance =

{(PMA)

+

(PEA)

+

(SMTE +

SD)

+ (SRA)

+ (SPE)

+ (STE)

+

(SMTE + SCA)

+

(RMTE + RD)

+ (RTE)

+

(RMTE + RCA) )

+

EA + BIAS 57

TABLE 3-18 STEAM GENERATOR NARROW RANGE WATER LEVEL - HIGH HIGH Parameter Process Measurement Accuracy j+a,c

]+a,c j+a,c j+a,c Allowance*

+a,c Primary Element Accuracy Sensor Calibration Accuracy Sensor Reference Accuracy Sensor Measuring 8 Test Equipment Accuracy Sensor Pressure Effects Sensor Temperature Effects Sensor Drift (30 months)

Environmental Allowance Rack Calibration Accuracy Rack Measuring 8 Test Equipment Accuracy Rack Temperature Effect Rack Drift

• In percent span (100%)

TABLE 3-18 (continued)

STEAM GENERATOR NARROM RANGE MATER LEVEL - HIGH HIGH Channel Statistical Allowance

=

((PMA)

+ (PEA)

+ (SMTE +

SD)

+ (SRA)

+

(SPE)

+ (STE)

+

(SMTE + SCA)

+

(RMTE + RD)

+ (RTE)

+

(RMTE + RCA) )

+

EA + BIAS

+OTIC 59

Parameter Process Measurement Accuracy j+a,c

]+a>c j+a,c j+a,c TABLE 3-19 RCS LOOP AT E(UIVALENT TO POWER j+a,c Allowance*

+a,c Primary Element Accuracy Sensor Calibration Accuracy

]+a>c Sensor Reference Accuracy j+a,c Sensor Measuring 5 Test Equipment Accuracy Sensor Pressure Effects Sensor Temperature Effects Sensor Orift Environmental Allowance dT - Cable IR Effects

(+1 F)

Rack Calibration Accuracy j+a>c Rack Measuring 8 Test Equipment Accuracy j+a,c 60

Parameter Rack Temperature Effect L

TABLE 3-19 (continued)

RCS LOOP hT EQUIVALENT TO POMER j+a>c Allowance*

+a,c Rack Drift j+a,c

• In percent hT span (bT - 96.6'F - Unit 1 (this is bounding for the Unit 1

uprated value of 98. 6'F); 97.5'F - Unit 2)

NH = )I'f hot leg RTDs

2 Nq

)5) of cold leg RTDs

=

1 Channel Statistical Allowance =

{ (PMA)

+

(PEA)

+

[)~SMTE r~+SD rl ~+SMTE r~+SCA rg

+

NH

~SMTE r~+SD r$ ~+SMTE r~+SCA r$ )j-+

Nc

({~RMTE r~+RD rj~+ATE r) ~+RMTE r~+RCA J +-

NH

~RMTE r~+RD rj~+RTE J ~+RMTE r~+RCA r)

)"g )" +-

Nc EA + BIAS

+a,c 61

TABLE 3-20 SEISMIC TRIP*

KINEMETRICS ELECTROMAGNETIC SEISMIC TRIGGERS MODEL TS-33A Parameter Process Measurement Accuracy Primary Element Accuracy Allowance*

+8,C Sensor Calibration Accuracy Sensor Reference Accuracy Sensor Measuring 5 Test Equipment Accuracy Sensor Pressure Effects Sensor Temperature Effects Sensor Drift (30 months)

Environmental Allowance Rack Calibration Accuracy Rack Measuring 5 Test Equipment Accuracy Rack Temperature Effect Rack Drift In units of acceleration, fraction of the gravitation constant, g.

(where g

= 32.2 ft/sec )

Not processed by Eagle-21 racks.

62

TABLE 3-20 (continued)

SEISMIC TRIP KINEMETRICS ELECTROMAGNETIC SEISMIC TRIGGERS MODEL TS-33A Channel Statistical Allowance =

((PMA)

+ (PEA)

+

(SMTE +

SD)

+ (SRA)

+ (SPE)

+

(STE)

+

(SMTE + SCA)

+

(RMTE + RO)

+ (RTE)

+

(RMTE + RCA)

}

+

EA + BIAS 63

TABLE 3-21 4.16 KV BUS UNDERVOLTAGE WESTINGHOUSE RELAYS/NOMINALSETPOINT 85 VOLTS This CSA is the responsibility of PG&E and will be developed as part of other activities.

• Not processed by Eagle-21 racks.

64

TABLE 3-21 (continued) 4.16 KV BUS UNDERVOLTAGE WESTINGHOUSE RELAYS/NOMINALSETPOINT 85 VOLTS Channel Statistical Allowance =

This CSA is the responsibility of PGhE and will be developed as part of other activities.

65

TABLE 3-22 4.16 KV BUS UNDERVOLTAGE**

WESTINGHOUSE RELAYS/NOMINAL SETPOINT 107.8 VOLTS This CSA is the responsibility of PGEE and will be developed as part of other activities.

• • Not processed by Eagle-21 racks.

66

TABLE 3-22 (continued) 4.16 KV BUS UNDERVOLTAGE MESTINGHOUSE RELAYS/NOMINAL SETPOINT 107.8 VOLTS Channel Statistical Allowance

=

This CSA is the responsibility of PG&E and will be developed as part of other activities.

67

TABLE 3-23 4.16 KV BUS UNDERVOLTAGE**

GENERAL ELECTRIC RELAYS/NOMINAL SETPOINT 82.45 VOLTS This CSA is the responsibility of PGEE and will be developed as part of other activities.

Not processed by Eagle-21 racks.

68

'TABLE 3-23 (continued) 4.16 KV BUS UNDERVOLTAGE GENERAL ELECTRIC RELAYS/NOMINAL SETPOINT 82.45 VOLTS Channel Statistical Allowance =

This CSA is the responsibility of PGKE and will be developed as part of other activities.

69

TABLE 3-24 4.16 KV BUS UNDERVOLTAGE**

GENERAL ELECTRIC RELAYS/NOMINAL SETPOINT 76.5 VOLTS This CSA is the responsibility of PGRE and will be developed as part of other activities.

Not processed by Eagle-21 racks.

70

TABLE 3-24 (continued) 4.16 KV BUS UNDERVOLTAGE GENERAL ELECTRIC RELAYS/NOMINALSETPOINT 76.5 VOLTS Channel Statistical Allowance =

This CSA is the responsibility of PGEE and will be developed as part of other activities.

71

This page intentionally left blank 72

TABLE3-25 REACTOR PROTECTION SYSTEM/ENGINEERED SAFETY FEATURES ACTUATIONSYSTEM CHANNELERROR ALLOWANCES DIABLOCANYON SENSOR 10 INSTRUMENTRACK 12 13 14 15 16 17 18 19 PAGE 73 6 PAGE 74 20 PROIECIIOM CHALXL 1

POWER RANGE,NEUTRON FNX HIGH SETPOWT 2

POh!KR RANGE. NEUIROMFLUX-LOWSETPOWT 3

POIIKRRANGE. NBJIROMFLUX-HIGH POQTIVE RATE 4

PNhKR RANGE.%UTRONFLUX-HIGHNEGATIVERATE 5

WTBL-Dl'Q.NEVTR(WFNX 6

SOURCE RANGE, AKVTRONFNX 7

NEGATIVESIEAMUNE PRESSURE RATE - HIGH PROCESS MEASUREhtENT ACCURACY 0)

PRDAARY ELEMBIT 0)

CAUBRAllOM 0)

REFERENCE 0)

MEASVREMENT 6 TEST EGIBPMENT ACCURACY 0)

PRESSURE EFrcCIS 0)

TEMPERATURE EFFECTS 0)

DRIFT 0)

ENNROM-MENTAL ALLOWANCE 0)

NIFASURKMENT 4r IKST CAUBRAllOM EOIBPMENT ACCURACY ACCURACY 0) 0)

COMPARATOR SETIING ACCURACY 0)

TEMPERATURE EIFECIB 0)

DRIFT 0

I AMAlYQS (2) 118'l RTP 3$'A'RTP (9)

(9)

(9)

(9)

ALLOWABLE VANE (3)

IIrh2'/i RTP 263% RTP sss RTpn scc 5$% RTpn sEc 1AEe5 CPS 102.4 PSI TRIP SETPOIMT (4) 10Fk RlP 25Yr RTP 5/e, RTpn 6EO 54% RTPn SEC 25'A RTP TOTAL ALLOWANCE 0)

CHAPEL STATISTICAL ALLOWANCE 0)

MARGW 0) 8 OVERTEMPERATURE aT aT CHANNEL Trrrg CHANNEL PRESSURIZER PRESSURE CHANEL al CHANAKL FUNCIION08)

FUNCTION 09) +

GABYaT epan tor ERI card Ih14Y aT epan 0.19% aT e pan FUNCTION 09) 9 OVERPOlhKR aT aT CHANNEL FUNCTION0 6)

RWCTION 09) +

GABYaT epen fVNCIIOM09) 10 PRESSVIVZER PRESSURE -LOW, REACTOR IHIP 11 PRESSVRZER PRESSURE 10GH Tery CHANNEL 1845 PSIG 1947$ PQG 2445 PSIG 10 12 P

ESSURIZER WATER LEVEL-HIGH 13 LOSS OF FNW 14 STEAM GENERATOR WATER LEVEL-LOW4.0W 15 UNDERVOLTAGE RCP 16 WOERRIEOEMCY-RCP 17 CONTAMNEMTPRESSURE - IBGH (9) 0% SPAN I

(9) 903% SPAN 7.0% SPAM 78.77 V(29) 3.1 2 PSIG 90th SPAM (22) 74th SPAN 8050 V(29) 3/I PQG 12 13 14 15 16 17 16 COMTADDABITPRESSURE IBGH-IBGH 19 PRESSUMZER PRESSURE - LOW,Sl 20 SIEAMUNEPRESSURE - UWV ( eeemouno 21 STEAMUNE PRESSURE - lDW (Barton) 22 STEAM GENERATOR WATER LEVEL-HIGIHIIGH 23 RCS LOOP aT EONVAIENTIO POWER aT CHANNEL 24.7 PSIG 1660 PSIG 22.12 PSIG 1847$ PQG 82% SPAM 753Y SPAN 444.0 PQG 597.6 PSIG 597.6 PSIG 22.0 PSIG 1850 PSIG 600 PSIG 600 PSIG 75'PAM 19 20 21 22 23 24 SE SLUG I

CHANNEL (31) 0359 24 NOTES:

2.

7.

8.

9.

10.

AU.VAUESARE SHOWN AS MAMTUKONLYAND LVPERCENT OF SPAM MESS OTHERWSE NOTED. QGNS SHOWN W TABLESMIHROUGH3 24.

AS NolED W SECTION 1$.1 OF THE UPDATED FSAIL AS CALCIRATEDUSWG THE APPROVKD McCOOOLOGYOF SECTION 43.

AS NOTED W DIABLOCANYONTECHNICALSPEISFICATIONS

(

]re@

(

(

l NOT USED W THE SAFElYANALYSIS LVCLVDEDIN]

] re 11.

12.

13.

14.

15.

16.

17.

18.

19.

]ea,o

]ceo INCLUDEDW ]

~C WOORE/ EXCORE I(dJ) COMPAIVSOMAS NOTED INIKONGAL SPECRCAllONS

]ea,c AS NOTED W FIGURE 15.1-1 OF UPDAlEDfSAR AS NOTED WTABtE22.1 OF DIABLOCANYONTECHNICALSPECfflCATIONS 20.

21.

22.

24.

2$.

27.

RECOMMENDED I)UP SETPOWT VAUIE

]ee,C

]e4g ROSEMOIWTTRAMSMITlERFA IERM PROVIDED BYPOSE -TREATED AS A BIAS CABLE WSUIAIIOMREQSIAVCEOEGRADATIONPROVIDED BY PGSE-TREAIEO AS A BIAS 28.

REFERENCE lEG HEAlUP EFFECT PROVIDED BYPOSE-TREATED AS A BIAS THESE TECHNICALSPECIFICATIONVAUKSHAVE SEEM CONVERIED TO THE EOUIVAIEMTVAL%SEEN BYIHE RELAYS BARTON ELEVAlCD TEMPERAllIRE EFFECTS PROVIDED BYPGSE-TREATKDAS A BIAS NOT USED W ACCIDENTANALYSISBUTPARTOF THE UCBSING BASIS FOR DCPP. UCENSWG BASIS ACCELERATIONSARE 0.75G HOIVZONTALANDOSG VERTICAL APERTL]RE CARD Atso Available on A e]ture Card I

I

', yvOZ/ZOZZ5 ro

SI l

I II Tj 4

TABLE 3-26 OVERTEMPERATURE hT CALCULATIONS

+

The equation for Overtemperature hT:

+~To Qj - IG

-T)+ EsP

>) f (>)j

(~+ rsvp

(~+ r~4 K> (nominal)

V(max)

Kp Vessel TH Vessel Tz 61 gain 1.20 Technical Specification value t:

j+a,c 0.0182/

F 0.000831/psi 608.8'F

• 544.4 F

• 2.38K RTP/X BI

+

Full power hT calculation:

hT span

= [

dT span pwr

= 150XRTP j+a,c

+

Process Measurement Accuracy Calculations:

+a,c

+a,c

+a,c These val ues are based on Unit 1 oper ating condi tions prior to power uprating which provi des the most conservative result.

75

TABLE 3-26 (continued)

OVERTEMPERATURE hT CALCULATIONS dI - Incore / Excore Mismatch EI - Incore Map Delta-I

+

Pressure Channel Uncertainties Gain

=

SCA SMTE =

STE SD RCA RMTE =

RTE RD 76

TABLE 3-26 (continued)

OVERTEMPERATURE AT CALCULATIONS

+ BI Channel Uncertainties Gain

=

+a,c RCA

+a,c RMTE =

RTE RD Total Allowance

+a,c These values are based on Unit 1 operating conditions prior to power uprating which provides the most conservative result.

77

TABLE 3-27 OVERPOMER hT CALCULATIONS The equation for Overpower hT:

~ 4To (K - K (

) T - K P' T"J - f'hl))

(s+ <,s)

'z+ <,s)

K4 (nominal)

K4 (max)

K5 K5 K6 Vessel TH Vessel Tz 1.072 Technical Specification value j+a>c 0.0 for decreasing average temperature 0.0174 for increasing average temperature (sec/

F)

0. 00145/'

608.8'F

• 544.4 F

• Full power hT calculation:

dT span

= [

hT span pwr

=

150'KRTP j+a,c

+

Process Measurement Accuracy Calculations:

+a,c

+a,c

+a,c Total Allowance

+a,c These values are based on Unit 1 operating conditions prior to power uprating which provides the most conservative result.

78

TABLE 3-28 hP MEASUREMENTS EXPRESSED IN FLOW UNITS The hP accuracy expressed as percent of span of the transmitter applies throughout the measured span, i.e.,

~1.5% of 100 inches hP

= ~1.5 inches anywhere in the span.

Because F'

f(hP) the same cannot be said for flow accuracies.

When it is more convenient to express the accuracy of a transmitter in flow terms, the following method is used:

(F>)

= hP>where N = Nominal Flow 2F BF

BhP thus BF

2FN Eq. 3-28.1 Error at a point (not in percent) is:

BFN Bh PN Bh PN FN 2(F)'h PN Eq. 3-28.2 and h PN (Fz)(F..)'q.

3-28.3 where max

= maximum flow and the transmitter hP error is:

(100) =percent error in Full Scale hP (X e FS hP)

Bh PN hP Eq. 3-28.4 79

therefore:

OFT FN Yo cFS LP1 100 J

Yo 8FS dP F

F (2)(100)

F 2kp Fm~

Eq. 3-28.5 Error in flow units is:

Yo b'FS LP Fmsx (2)(100)

FN Eq. 3-28.6 Error in percent nominal flow is:

By'~(

)

Yo zFS dd'N 2

FN Eq. 3-28.7 Error in percent full span is:

Yo zFS M F

(1pp) F

~

F (100)

Fmg(

Fmac (2)(100)

FN Yo sFS LP F

FN Eq. 3-28.8 Equation 3-28.8 is used to express errors in percent full span in this document.

80

4.0 APPLICATION OF THE SETPOINT METHODOLOGY 4.1 Uncertainty Calculation Basic Assumptions/Premises The equations noted in Sections 2 and 3 have several basic premises which were determined by a systematic review of the calibration procedures utilized at Diablo Canyon Units 1 and 2 and statistical evaluations of "as left" and "as found" data for the RPS/ESFAS functions noted in Tables 3-6 through 3-24:

1) the instrument technicians optimize, within the calibration tolerance, the Nominal Setpoint's "as left" condition at the start of each process rack's surveillance interval,

2) the instrument technicians optimize, within the calibration tolerance, the sensor/transmitter's "as left" condition at the start of each surveillance interval,

3) the process rack drift is limited by the Eagle 21 self-checking

feature,

4) the sensor/transmitter drift is trended over the fuel cycle and evaluated (probability distribution function characteristics and drift magnitude) over multiple fuel cycles,

5) the sensor/transmitter calibration accuracy is evaluated (probability distribution function characteristics and magnitude) over multiple surveillance intervals,

6) the sensor/transmitters are calibrated using a one up and one down pass utilizing multiple calibration points (minimum 5 points, as recoranended by ISA51.1 '

It should be noted for (1) and (2) that it is not necessary for the instrument technician to recalibrate a device or channel if the "as left" condition is not exactly at the nominal condition but is within the plus or minus "as left" procedural tolerance.

As noted above, the 81

uncertainty calculations assume that the "as left" tolerance (conservative and non-conservative direction) is satisfied on a statistical

basis, not that the nominal condition is satisfied exactly.

Westinghouse evaluated, using actual Diablo Canyon "as left" data, the achieved sensor calibration accuracy (as-left data) for the RPS/ESFAS sensor/transmitters for Diablo Canyon Units 1 and 2 over multiple calibration cycles and verified them to be consistent with procedural tolerances and the assumptions of the statistical uncertainty combination methodology.

In summary, a sensor/transmitter or a process rack channel is considered to be "calibrated" when the two-sided "as left" calibration procedural tolerance is satisfied.

An instrument technician may decide to recalibrate if the "as found" condition is near the extremes of the "as left" procedural tolerance, but it is not required to do so.

Recalibration is explicitly required any time the "as found" condition of the device or channel is outside of the "as left" procedural tolerance.

A device or channel may not be left outside the "as left" tolerance without declaring the channel "inoperable" and appropriate action taken.

Thus an "as left" tolerance may be considered as an outer limit for the purposes of calibration and instrument uncertainty calculations.

As part of this effort, drift data

("as found" - "as left") for the sensor/transmitters was evaluated.

Where data was available, multiple surveillance intervals were evaluated to determine the appropriate values for drift for a surveillance interval of 30 months.

This evaluation determined that the SD parameter values noted in Tables 3-1 through 3-24 were satisfied on a 95

'X probability / 95 X confidence level basis for a 30 month surveillance interval.

Generic Letter 91-04 'l requires that drift be monitored or trended on a periodic basis.

The equations used in Sections 2 and 3, assume that drift data is evaluated for continuation of the validity of the basic characteristics determined by the Westinghouse evaluation.

This assumption has a

significant beneficial effect on the basic uncertainty equations utilized, i.e., it results in a reduction in the CSA magnitude.

82

4.2 Sensor/Transmitter Procedural Evaluation Generic Letter 91-04, Enclosure 2, requires that the assumptions of the setpoint evaluations be appropriately reflected in plant surveillance procedures and that a program be in place to monitor and assess the effects of increased calibration surveillance intervals on instrument drift and its effect on safety.

The program should ensure that existing procedures provide data for evaluating the effects of increased calibration intervals.

The data should confirm that the estimated errors for instrument drift with increased calibration intervals are within projected limits.

This requirement to monitor instrument drift is consistent with the format of the uncertainty equations noted in Sections 2 and 3 of this WCAP, whereby calibration accuracy and drift are treated as two statistically independent parameters.

An implication of this format is that equipment performance should be evaluated

based, not only on the capability of the equipment to be calibrated, but also on continued equipment performance which is consistent with the drift allowances based on historical performance and incorporated in the uncertainty calculations.

As input to the verification that sensor/transmitter performance is consistent with the assumptions of the setpoint evaluations, an initial surveillance test procedure evaluation criterion is used, based on an "as found" tolerance about the nominal value.

A reasonable value for this tolerance is SNTE + SD.

SD is the 95/95 drift value identi.fied in the Diablo Canyon statistical setpoint study based on historical performance, and SMTE is the uncertainty for the MTE used to calibrate the sensors as identified in the Diablo Canyon Units I and 2 procedures.

Values for the "as found" tolerance evaluation are provided in Table 4.2-1, The tolerance represents the value for the evaluation criterion based on the SNTE program presently used at Diablo Canyon.

These criteria for sensors can be incorporated into plant procedures as the defined "as found" tolerance about the desired calibration value.

If the device is found to be outside these criterion, the device characteri stics will be evaluated in conjunction with the previous experience for that specific device to determine whether the device 83

performance is within the assumptions of the Diablo Canyon statistical setpoint study. Additional criteria for field performance evaluation are the ability to calibrate the sensor/transmitter within the two-sided "as left" tolerance and the qualitative response characteristics of the device.

The approach described here provides a reasonable set of initial criteria for input to the sensor/transmitter performance evaluation when used in conjunction with the Diablo Canyon drift monitoring and assessment program.

The Diablo Canyon drift monitoring and assessment program should confirm that the observed instrument drift with increased calibration intervals is within the projected limits.

More elaborate evaluation and more frequent on-line monitoring may be included, as necessary, if the drift appears to be excessive or the device is difficult to calibrate.

84

TABLE 4.2-1 SENSOR/TRANSMITTER AS-FOUND CRITERIA FUNCTION CRITERIA (SD + SMTE)

PRESSURIZER PRESSURE -

LOW, REACTOR TRIP PRESSURIZER PRESSURE - HIGH PRESSURIZER WATER LEVEL - HIGH LOSS OF FLOW STEAN GENERATOR WATER LEVEL -

LOW-LOM UNDERVOLTAGE - RCP UNDERFREOUENCY -

RCP CONTAINHENT PRESSURE - HIGH CONTAINMENT PRESSURE - HIGH-HIGH PRESSURIZER PRESSURE -

LOW, SI STEAHLINE PRESSURE -

LOW (Rosemount)

STEAHLINE PRESSURE -

LOW (Barton)

STEAM GENERATOR MATER LEVEL - HIGH-HIGH SEISMIC 85

4.3 Process Rack Operability Determination Program and Criteria A program has been determined to define operability criteria for the Eagle 21 digital process racks.

Since the process racks are self-

checking, the critical parameter is the ability of the process racks to be calibrated within the Rack Calibration Accuracy.

These values are currently found in the plant calibration procedures as the "as left" calibration accuracy, and are consistent with the Eagle 21 card/channel Analog Input Verification Test Criteria with the following values:

+a,c EAI ERI-NR (TEMP)

ERI-WR (TEMP)

ERI-WR (Voltage)

A channel found in excess of the Rack Calibration Accuracy and less than or equal to the Allowable Value, designated as (RD + RMTE), should be considered operable if the "as left" condition can be returned to within the Rack Calibration Accuracy.

If the measured setpoint is found in excess of the Allowable Value, the channel bistable/output device must be evaluated for operability.

The channel will be considered inoperable if it cannot be returned to within the Rack Calibration Accuracy regardless of the "as found" value.

The Allowable Values are defined as:

EAI ERI-NR (TEMP)

ERI-WR (TEMP)

ERI-WR (Voltage) 0.20K Span 0.30K Span 0.20%

Span 0.20'X Span For the Nuclear Instrument channels, PGLE will use the same definition for Allowable Value as is being applied to the other channels in this setpoint study, i.e. the difference between the Allowable Value and the Nominal Trip Setpoint equals Rack Drift plus Rack Measuring 8 Test Equipment accuracy.

86

4.4 Application to the Plant Technical Specifications Westinghouse recommends revision of Table 2.2-1 "Reactor Trip System Instrumentation Setpoints" and Table 3.3-4, "Engineered Safety Features Actuation System Instrumentation Trip Setpoints" in the Technical Specifications.

Appendix A provides the Westinghouse recommendations for revision of these two tables with the recoranended Nominal Trip Setpoint and Allowable Value for each RPS/ESFAS protection function, which was utilized in the Westinghouse uncertainty calculations and determined to be acceptable for use.

4.5 References/Standards

[1j Instrument Society of America Standard S51.1-1979 (Reaffirmed 1993),

"Process Instrumentation Terminology",

p 33.

[2j Generic Letter 91-04,

1991, "Changes in Technical Specification Surveillance Intervals to Accommodate a 24 month Fuel Cycle."

87

APPENDIX A SAMPLE DIABLO CANYON UNITS I AND 2 SETPOINT TECHNICAL SPECIFICATIONS

TABLE 2.2-1 REACTOR TRIP SYSTEM INSTRUMENTATION TRIP SETPOI TS FUNCTI NAL UNIT OMINAL TRIP SETPOINT ALLOWABLE VALUES 2.

Manual Reactor Trip Power

Range, Neutron Flux, N.A.

N.A.

a.

Low Setpoint

b. High Setpoint 5 25K of RATED THERMAL POWER 5 109K of RATED THERMAL POWER 5 26,2X of RATED THERMAL POWER 5 110.2X of RATED THERMAL POWER 3 ~

Power Range, Neutron Flux, High Positive Rate 5 5X of RATED THERMAL POWER with a time constant

> 2 seconds 5 5.6X of RATED THERMAL POWER with a time constant 2 2 seconds 4.

Power Range, Neutron Flux, High Negative Rate 5 5X of RATED THERMAL POWER with a time constant

> 2 seconds 5 5.6X of RATED THERMAL POWER with a time constant 2 2 seconds 5.

Intermediate

Range, Neutron Flux 5 25K of RATED THERMAL POWER 5 30,6X of RATED THERMAL POWER 6.

Source

Range, Neutron Flux 7.

Overtemperature hT 8.

Overpower dT 9.

Pressurizer Pressure

- Low 10.

Pressurizer Pressure

- High 11.

Pressurizer Water Level - High 12.

Reactor Coolant Flow - Low 5 10 counts per second See Note 1

See Note 3 2 1950 psig M 2385 psig 5 90% of instrument span 2 90$ of minimum measured flow**per loop 5 1.4 x 10'ounts per second See Note 2 See Note 4 2 1947.5 psig 5 2387.5 psig 5 90.2% of instrument span c 89.8X of minimum measured flow**per loop Minimum Measured Flow Per Loop = 89,800 gpm per loop for Unit 1 and 90,625 gpm per loop for Unit 2.

A-2

TABLE 2.2-1 (Continued)

FU CTIONAL IT REA TOR TRIP SYSTEM I STRUHENTATION TRIP SETPOINTS NOMINAL TRIP SETPOINT ALLOWABLE VALUES 13.

Steam Generator Mater Level - Low-Low Coincident with:

a.

RCS Loop hT Equivalent to Power 5 50K RATED THERMAL POWER With a time delay (TD)

OR b.

RCS Loop hT Equivalent to Power

> 50K RATED THERMAL POWER With no time delay 14.

DELETED 15.

Undervoltage -

RCP 16.

Underfrequency -

RCP

> 7.2% of narrow range instrument span - each steam generator RCS Loop hT variable input 5 50K RTP 5 TD (Note 5)

RCS Loop hT variable input

> 50K RTP TD = 0 2 8050 V each bus 2 54.0 Hz each bus 2 7.0K of narrow range instrument span - each steam generator RCS Loop hT variable input 5 50.7K RTP 5 (1.01)TD (Note 5)

RCS Loop hT variable input

> 50.7X RTP TO=0 2 7877 V each bus 2 53.9 Hz each bus 17.

Turbine Trip a.

Low Autostop Oil Pressure b, Turbine Stop Valve Closure 2 50 psig 2 1$ open c 45 psig 2

1X open 18.

Safety Injection Input from ESF NBA.

N.A.

19.

RCP Breaker Position Trip 20.

Reactor Trip Breakers N.A.

N.A.

N.A.

N.A.

A-3

FUNCTIONAL UNIT 21.

Automatic Trip and Interlock Logic 22.

Reactor Trip System Interlocks TABLE 2.2-1 (Continued)

REACTOR TRIP SYSTEM INSTRUME TATION TRIP SETPOINTS NOMINAL TRIP SETPOINT N.A.

ALLOWABLE VALUES N.A.

a, Intermediate Range Neutron Flux, P-6 2

1 x 10-10 amps 2 8 x 10-11 amps b.

Low Power Reactor Trips Block, P-7 1.

P-10 input

2. P-13 input c.

Power Range Neutron Flux, P-8 10X of RATED THERMAL POWER 5 10X RATED THERMAL POWER Turbine Impulse Pressure Equivalent 5 35X of RATED THERMAL POWER

> 8.8X, 5 11.2X of RATED THERMAL POWER 5 10.2X RATED THERMAL POWER Turbine Impulse Pressure Equivalent 6 36.2X of RATED THERMAL POWER d.

Power Range Neutron Flux, P-9 5 50X of RATED THERMAL POWER 5 51.2X of RATED THERMAL POWER e.

Power Range Neutron Flux, P-10 10X of RATED THERMAL POWER 2 8.8X, 5 11.2X of RATED THERMAL POWER

f. Turbine Impulse Chamber

Pressure, P-13 23.

Seismic Trip 5 10X RATED THERMAL POWER Turbine Impulse Pressure Equivalent 5 0.35 g

K 10.2X RATED THERMAL POWER Turbine Impulse Pressure Equivalent 5 0.43 g

A-4

TABLE 2.2-1 (Continued)

TABLE NOTATION NOTE 1:

OVERTEMPERATURE AT I + x S 1+ x S

5 1+ xIS

<bT {K-K (

[T-T']+K(P-P') - f (BI)}

o 1

Z 1+x2 3

1 Where:

I+xS I+xS 4'

hT 0

K (nominal)

Measured hT by Reactor Coolant System Instrumentation; Lead-lag compensator on measured bT Time constants utilized in the lead-lag controller for hT, ~

= 0 secs.,

~

= 0 secs.

Loop specific Indicated hT at RATED THERMAL POWER; 1.20 K (nominal)

I+~S I+xS 1'

T

0. 0182/'F The function generated by the lead-lag compensator for T dynamic compensation; avg Time constants utilized in the lead-lag compensator for T

~1 30 secs.,

~2 = 4 secs.

avg' Average temperature,

'F A-5

TABLE 2.2-1 (Continued)

TABLE NOTATION Continued NOTE 1:

(continued)

K> (nominal) pl Nominal Loop specific Indicated T,, at RATED THERMAL POWER 0.000831/psi g Pressurizer

pressure, psig 2235 psig (Nominal RCS operating pressure)

Laplace transform operator, sec ',

and f>(hI) is a function of the indicated difference between top and bottom detectors of the power range nuclear ion chambers; with gains to be selected based on measured instrument response during plant startup tests such that:

for q, -

q> between

-19K and

+7%, f>(d,I)

= 0 (where q, and qq are percent RATED THERMAL POWER in the top and bottom halves of the core respectively, and q, + q> is total THERMAL POWER in percent of RATED THERMAL POWER);

(2) for each percent that the magnitude of (q, - q>) exceeds

-19K, the d T trip setpoint shall be automatically reduced by 2.75K of its value at RATED THERMAL POWER; and (3) for each percent that the magnitude of (q, - q>) exceeds

+7%, the hT Trip Setpoint shall be automatically reduced by 2.38K of its value at RATED THERMAL POWER.

Note 2:

The Channel's maximum trip setpoint shall not exceed its computed trip setpoint by more than 0.46K bT span for hot leg or cold leg temperature inputs, 0. 14K hT span for pressurizer pressure input, or 0. 19K hT span for 8,1 inputs.

A-6

TABLE 2.2-1 (Continued)

TABLE NOTATION Continued NOTE 3:

OYERPOWER hT (1 + xS) x S bT

<hT

{K -K

(

) T-KIT-T]- f (hI))

1+~5S o

4 5

1+~S 6

2 3

Where:

1 + x S

1 + w S

4' hT 0

K4 (nominal)

Ks (nominal) z3S 1 + w S

'3 Measured hT by Reactor Coolant System Instrumentation; Lead-lag compensator on measured dT Time constants utilized in the lead-lag controller for dT,

~

= 0 secs.,

~

= 0 secs.

Loop specific Indicated hT at RATED THERMAL POWER; 1.072 0.0174/'F for increasing average temperature and 0 for decreasing average temperature The function generated by the rate-lag compensator for T dynamic compensation avg Time constants utilized in the rate-lag compensator for T

, ~

= 10 secs.

avg 3

A-7

TABLE 2.2-1 (Continued)

TABLE NOTATION Continued NOTE 3:

(continued)

K, (nominal)

=

0.00145/'F for T > T" and 0 for T < T" Average temperature,

'F Hominal loop specific Indicated T,, at RATED THERMAL POWER Laplace transform operator, sec ',

f (AI) 0 for all hI NOTE 4:

The Channel's maximum trip setpoint shall not exceed its computed trip setpoint by more than 0.46K hT span.

A-8

TABLE 2.2-1 (Continued)

TABLE OTATION Continued Note 5:

Steam Generator Water Level Low-Low Trip Time Delay TD = B1(P)

+ B2(P)

+ B3(P)

+ B4 Where:

P

=

RCS Loop dT Equivalent to Power (X RTP),

P S 50K RTP TD = Time delay for Steam Generator Water Level Low-Low Reactor Trip ( in seconds).

B1

= -0.007128 B2 = +0.8099 83

= -31.40 84

= +464.1 A-9

TABLE 3'-4 ENGI EERED AFETY FEATURE ACTUATION SYSTEM I STRUMENTATION TRIP SETPOINTS FU CTIONAL UNIT NOMINAL TRIP SETPOI T

ALLOWABLE VALUES Safety Injection (Reactor Trip, Feedwater Isolation, Start Diesel Generators, Containment Fan Cooler

Units, and Component Cooling Water) a.

Manual Initiation b.

Automatic Actuation Logic c.

Containment Pressure

- High d.

Pressurizer Pressure

- Low e.

DELETED f.

Steamline Pressure

- Low N.A.

5 3 psig h 1850 psig 2 600 psig (NOTE 1)

N.A.

N.A.

5 3.12 psig

> 1847.5 psig 2 597.6 psig (NOTE 1) 2.

Containment Spray a.

Manual Initiation N.A.

N.A.

b.

Automatic Actuation Logic and Actuation Relays c.

Containment Pressure

- High-High N.A, 5 22.0 psig N.A.

~ 22.12 psig A-10

TABLE 3.3-4 (Continued)

ENGINEERED SAFETY FEATURES ACTUATION SYSTEM INSTRUMENTATION TRIP SETPOINTS FUNCTIONAL UNIT NOMINAL TRIP SETPOINT ALLOWABLE VALUES 3.

Containment Isolation a.

Phase "A" Isolation

1) Manual Initiation

2) Automatic Actuation Logic and Actuation Relays N.AD N.A.

N.A.

N.A.

3) Safety Injection See Item 1 above for all Safety Injection Trip Setpoints and Allowable Values.

b.

Phase "B" Isolation

1) Manual Initiation N.A.

N.A.

2) Automatic Actuation Logic and Actuation Relays N.A.

N.AD

3) Containment Pressure-High-High 5 22.0 psig 5 22.12 psig c.

Containment Ventilation Isolation

1) Automatic Actuation Logic and Actuation Relays N.A.

N.AD

2) Deleted

3) Safety Injection

4) Containment Ventilation Exhaust Radiation-High (RM-44A and 44B)

See Item 1 above for all Safety Injection Trip Setpoints and Allowable Values.

Per the ODCP

TABLE 3.3-4 (Continued)

ENGINEERED SAFETY FEATURES ACTUATION SYSTEM I STRUHENTATION TRIP ETPOINTS FUNCTIONAL UNIT ONINAL TRIP SETPOINT ALLOWABLE VALUES 4.

Steam Line Isolation a.

Manual Initiation b.

Automatic Actuation Logic and Actuation Relays N.A.

N.A.

N.A.

N.A.

c.

Containment Pressure

- High-High d.

Steamline Pressure

- Low e.

Steam Line Pressure-Negative Rate - High 5 22.0 psig

> 600.0 psig (NOTE 1) s 100 psi (NOTE 3) 5 22.12 psig

~ 597.6 psig (NOTE 1)

~ 102.4 psi (NOTE 3) 5 ~

Turbine Trip and Feedwater Isolation a.

Automatic Actuation Logic Actuation Relays N.A.

N.A.

b.

Steam Generator Water Level High-High 5 75K of narrow range instrument span each steam generator.

< 75.2K of narrow range instrument span each steam generator A-12

TABLE 3.3-4 (Continued)

ENGINEERED SAFETY FEATURES ACTUATION SYSTEM INSTRUMENTATION TRIP SETPOI TS FUNCTIONAL UNIT HOMINAL TRIP SETPOINT ALLOWABLE VALUES 6.

Auxiliary Feedwater a,

Manual Initiation N.A.

b.

Automatic Actuation Logic and Actuation Relays N.A.

N.A.

c.

Steam Generator Water Level - Low-Low Coincident with:

1)

RCS Loop dT Equivalent to Power ~ 50'K RTP With a time delay (TD) 2 7.2% of narrow range instrument span - each steam generator RCS Loop hT variable input 5 50'K RTP 5 TD (NOTE 2) 2 7.0X of narrow range instrument span - each steam generator RCS Loop hT variable input 5 50.7X RTP 5 (1.01)TD (NOTE 2)

OR 2)

RCS Loop ET Equivalent to Power > 50K RTP RCS Loop hT variable input

> 50'5 RTP RCS Loop hT variable input

> 50.7%

RTP With no time delay TD=0 TD = 0 d.

Undervoltage -

RCP e.

Safety Injection 2 8050 volts 2 7877 volts See Item 1 above for all Safety Injection Trip Setpoints and Allowable Values.

A-13

TABLE 3.3-4 (Continued)

ENGINEERED SAFETY FEATURES ACTUATION SYSTEH INSTRUHENTATI N TRIP SETPOINTS FUNCTIONAL UNIT NOHINAL TRIP SETPOINT ALLOWABLE VALUES 7.

Loss of Power (4. 16 kV Emergency Bus Undervoltage) a.

First Level 1)

Diesel Start TBD by PG&E TBD by PG&E 2)

Initiation of Load Shed TBD by PG&E TBD by PG&E b.

Second Level 1)

Diesel Start TBD by PG&E TBD by PG&E 2)

Initiation of Load Shed TBD by PG&E TBD by PG&E 8.

Engineered Safety Features Actuation System Interlocks a.

Pressurizer

Pressure, P-11 K 1915 psig C 1917.5 psig b.

DELETED

-c, Reactor Trip, P-4 N.AD N.AD A-14

TABLE 3.3-4 (Continued)

TABLE NOTATIONS NOTE 1:

Time constants utilized in the lead-lag controller for Steam Pressure-Low are ~>

= 50 seconds and ~z

= 5 seconds.

NOTE 2:

Steam Generator Water Level Low-Low Trip Time Delay TD = 81(P)

+ 82(P)

+ B3(P)

+ B4 Where:

P

=

RCS Loop AT Equivalent to Power (X RTP),

P < 50K RTP TD = Time delay for Steam Generator Water Level Low-Low Reactor Trip ( in seconds).

B1

= -0.007128 B2

= +0.8099 B3

= -31.40

, B4 = +464.1 NOTE 3:

The time constant utilized in the rate-lag controller for Negative Steam Line Pressure Rate - High are

~q

= 50 seconds and ~4

= 50 seconds.

A-15