ML20092H465

Nonproprietary Westinghouse Setpoint Methodology for Protection Sys,Comanche Peak Station. W/Two Oversize Tables.Aperture Cards Available in PDR

ML20092H465
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Site:	Comanche Peak
Issue date:	05/31/1984
From:	Miller R, Tuley C WESTINGHOUSE ELECTRIC COMPANY, DIV OF CBS CORP.
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WESTINGHOUSE PROPRIETARY CLASS 3

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WESTINGHOUSE SETPOINT METH000 LOGY FOR PROTECTION SYSTEMS COMAtiCHE PEAK STATION MAY, 1984 i

C. R. Tuley R. B. Miller f

- This document contains information proprietary to Westinghouse Electric Corporation;-it is submitted in confidence and is to be used solely for the purpose for which it is furnished and returned upon' request. This doc'ument and tuch information is not to be reproduced, transmitted, disclosed or used otherwise

'in whole or in part without authorization of Westinghouse Electric Corporation, Nuclear Energy Systems.

WESTINGHOUSE ELECTRIC Nuclear Energy Systems-P. O. Box 355 Pittsburgh, Pennsylvania 15220 8406260126 840607 PDR ADOCK 05000445 PDR A

bilrightsreserved.

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si,, '1 WESTINGHOUSE PROPRIETARY CLASS 3

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p TABLE OF CONTENTS Title Pace Section 1 -1

1.0 INTRODUCTION

2 -1

~

' 2.0 . COMBINATION OF ERROR COMPONENTS Methodology 2-1 2.1 2.2 Sensor Allowances 2-3 Rack Allowances 2-5 2.3 2-6

-2.4 Proces,s Allowances ,

3-1 3.0 PROTECTION SYSTEMS SETPOINT METHODOLOGY Margin Calculation 3-1 3.1 Definitions for Protection System 3-1 3.2 Setpoint Tolerances Statistical 'ethodology Conclusion 3-6 3.3 4-1 4.0 ~ TECHNICAL SPECIFICATI0 USAGE ,

4-1 4.1 Current Use Westinghouse Statistical Setpoint 4-2 l 4.2

. Methodology for STS Setpoints 4.2.1 Rack Allowance 4-2 Inclusion of "As Measured" 4-3 4.2.2 -

Sensor Allowance ,

4-4 4.2.3 Implementation of the Westinghouse Setpoint Methodology 4-8 4.3 Conclusion A-1

-Appendix A SAMPLE COMANCHE PEAX SETPOINT TECHNICAL SPECIFICATIONS II

s .

5 8 WESTINGHOUSE PROPRIETARY CLASS 3 a

LIST OF TABLES Title _ Ea qe Table 3-1 Power Range, Neutron Flux-High and Low Setpoints 3-7 3-2 Power Range, Neutron Flux-High Positive Rate and 3-8 High Negative Rate 3-3. Intermediate Range, Neutron Flux 3-9 3-10 3-4 Source Range, Neutron Flux Overtemperature N-16 3-11 3-5 Overpower N-16 3-13 3-6 .

Pressurizer Pressure - Low and High, Reactor Trips 3-15 3-7 Pressurizer Water level - High 3-16 3-8 Loss of Flow 3-17 3-9 Steam Generator Water Level - Low-Low Unit 1 3-18 3-10a Steam Generator Water Level - Low-Low Unit 2 3-19 3-10b 3-11 Containment Pressure - High, High-High, and 3-20 High-High-High, 65 psi span Pressurizer Pressure - Low, Safety Injection 3-21 3-12 Steamline Pressure - Low 3-22 3-13 Negative Steamline Pressure Rate - High 3-23 3-14 .

Steam Generator Water Level.- High-High Unit 1 3-24 3-15a Steam Generator Water Level - High-High Unit 2 3-25 3-15b Reactor Protection System / Engineered Safety Features 3-26 3-16 Actuation System Channel Error Allowances Overtemperature N-16 Gain Calculations 3-27 3-17 Overpower N-16 Gain Calculations 3-29 3-18 Steam Generator Level Density variations 3-31 3-19 AP' Measurements Expressed in Flow Units 3-32 3-20

-Low, low-Low N-16 3 3-21 -T, 3-37 22 T,yg-low, low-Low N-15 Gain Calculations Precision Flow Measurement 3-39 3-23 3-41 3-24 RWST Level - Automatic Switchover III

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i % $t  : ' WESTINGHOUSE PROPRIETARY CLASS 3

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LIST OF TABLES (Continued)

$t Table- ~Tftle- Pa.ge Examples _of-Current STS Setpol'nts. Philosophy 4-10 l4-1

- Examples of 'Aestinghouse STS Rack Allowance 4-10 4-2

'destinghouse Protection System STS Setpoint Inputs 4-13

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4 3 WESTINGHOUSE PROPRIETARY CLASS 3 LIST OF ILLUSTRATIONS Title Page Ficure 4-1 NUREG-0452 Rev. 4 Setpoint Error 4-11 Breakdown Westinghouse STS Setpoint Error 4-12 4-2 Breakdown V

I ~ WESTINGHOUSE PROPRIETARY CLASS 3

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1.0 INTRODUCTION

In March of 1977, the NRC reque'sted several utilities with Westinghouse Nuclear Steam Supply Systems to reply to a series of questions concern-ing the methodology for determining instrument setpoints. A statistical >

methodology was developed in response to those questions with a corres-ponding defense of the technique used a determining the overall allowance for each setpoint.

The basic underlying assumption used is that several of the error com-ponents and their parameter assumptions act independently, e.g., (

]+a,c . This allows

,the use of a statistical summation of the various breakdown components instead of a strictly arithmetic summation. A direct benefit of the use

-of this technique is increased margin in the total allowance. For those parameter assumptions known to be interactive, the technique uses the normal, conservative approach, arithmetic summation, to form independent

.q uantitles, e.g., ( ]+". 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 in the setpoint parameter breakdown, thus insuring a clear understanding of the breakdown. Also provided is a detailed example of each setpoint margin ca,lculation demonstrating the technique and noting how each parameter value is derived. In nearly all cases, significant margin exists between the statistical summation and the total allowance.

Section 4.0 notes what the current (read NRC) Technical Specifications use for setpoints and an explanation of the impact of the statistical approach on them. Detailed examples of how to determine the Technical Specification setpoint values are also provided. An Appendix is pro-vided noting a recommended set of Technical Specifications using the plant specific data in the statistical approach.

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'amMMaSt5aAA 11

WESTINGHOUSE PROPRIETARY CLASS 3 2.0 CCMSINATION OF ERROR CCMPCNENTS 2.1 METH000 LOG (

The methodology used to combine the error components for a enannel is basically the appropriate statistical combination of those groups of components which are statistically independent, i.e., not interactive.

Those errors which are not independent are placed arithmeiically into groups. The groups themselves are independent effects which can then be

' systematically combined.

Basically it is The methodology used for this combination is not new.

the [ ]**' which has been utilized in other Westinghouse reports. This technique, or other-statistical approaches of a similar nature, have been used in ~

WCAP-9180 II) and WCAP-8567(2). It should be noted that WCAP-8567 has been approved by the NRC Staff thus noting the acceptability of statistical techniques for the application req 0ested. It should also be recognized that ANSI, the American Nuclear Society, and the Instrument Society of America approve of the use of probabilistic techniques l'n

) Thus it can be seen that determining safety-related setpoints( .

'the use of statistical approaches in analysis techniques is becoming more and recre widespread.

Kopelic, S. O., and Chelemer, H., " Consideration of (1) Little, C.C.,

Uncertainties in the Specification of Core Hot Channel Factor Limits." WCAP-9180 (Proprietary), WCAP-9181 (Non-Proprietary),

Sep tembe r, 197 7.

R., almproved Thermal (2) Chelemer, H., Boman, t.. H., and Sharp, O.

Design Procedure," WCAP-8567 (Proprietary), WCAP-8568 (Non-Proprietary), July, 1975. ,

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

567.04-1982, *Setpoints for Nuclear Safety-Related (4) ISA Standard Instrumentation used in Nuclear Power 31 ants."

65Mt1N013194 2-1

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- WESTINGHOUSE PROPRIETARY ~ CLASS 3

-The relationship between the error components and the total statistical error allowance for a channel i,s, l

~

- +a,c l

~

(Eq. 2-11 t

where:

CSA = . Channel Statistical Allowance PMA = Process Measurement Accuracy PEA = Primary Element Accuracy SCA = Sensor Calibration Accuracy l

50 = Sensor Orlft STE = Sensor Temperature Effects SPE = Sensor Pressure Effects RCA = Rack Calibration Accuracy RCSA = Rack Comparator Setting Accuracy R0 = Rack Or1ft .

i RTE - Rack Temperature Effects 4

EA = Environmental Allowance As can be seen in Equation 2.1, ( ]+a,c allowances are interactive and thus not independent. The ( j

)+a,c is not necessarily considered interactive with all other parameters, but as an additional degree of conservatism is added to the statistical sum. It should be noted that for this document it l

• was assumed that the accuracy ef f ect on a chann'el due to cable degra-dation.in an accident environment will be less than 0.1 percent of .

span. This impact has been considered negligible and is not factored into the analysis. An error due to this cause found to be in excess of' .

0.1 percent of span must be directly added as an environmental error.

The Westinghouse setpoint methodology results in a value with a 95 per-i c1nt probaDility with a high confidence level. With the exception of

' Process Measurement accuracy, Rack Orfft, and Sensor Ortft. all l

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. i WESTINGHOUSE PROPRIETARY CLASS 3

.ncertainities assimec are the extremes of the ranges of the various parameters, i.e., are 0etter than 2e values.

Rack Drift and Sensor Orift are assumed, based on a survey of reported plant LERS, and with Drocess Measurement Accuracy are considered as conservative values.

2.2 SENSCR ALLCWANCES Four parameters are considered to be sensor allowances, SCA, 50, STE, and SPE (see Table 3-16).

Of these four parameters, two are considered to be statistically independent, ( ]* , and two are con-

]+a,c g )+a,c are con-sidered interactive [ ,

sidered to be independent due to the manner in which the instrumentation is checked, i.e., the instrumentation is [

An example of this would be as follows; assume a *a ,c

]*#'# .

~

~

[ )**'" are considered to be interactive f or' the same reason i.e., due to the that [ ]+a,c are considered indepencent, manner in which the instrumentation is checked. (

. + a,c j

2-3 45550: 10/013184 _

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' WESTINGHOUSE PROPRIETARY CLASS 3 .

(

]*8'C .

Based on this reasoning, [

]

'have been added to for',m an independent group which is then factored into Equation 2.1. An example of the impact of this treatment is; for Pressurizer Water level-High (sensor parameters ,only):

+a,c using Equation 2.1 as written gives a total of;

+a,c

= 1.66 percent .

Assuming no interactive effects for any of the parameters gives the following results: .

. +a ,c

'(EQ. 2.2)

= 1.32 percent

-Thus it can Ebe seen that the approach represented by Equation 2.1 which accounts for interactive parameters results in a more conservative sum-mation of the allowances.

-- . - 45!!0:10/01318a ?A

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WESTINGHOUSE PROPRIETARY CLASS 3

, I 2.3 4ACK ALLCWANCES Four parameters, as noted by Ta-ble 3-16, are considered to be rack allowances, RCA, RCSA, RTE, and RO. Three of these parameters are considered to be interactive (for much the same reason outlined for sensors in 2.2), [ ]+a,c ,

( ,

l

-]**. Based on this logic, these three factors have been added to form an independent group. This group is then factored into Equation 2.1. The impact of this approach-(formation of an independent group based on interactive components) is significant. For the same channel using the same approach outlined in Equations 2.1 and 2.2 the following results are reached:

. +a ,c ,

i

.using Equation 2.1 the result is:

. +a,c

= 1.32 percent 2-5 45550:10/013184 ,

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.,y .. -

- WESTINGHOUSE PROPRIETARY CLASS 3 Assuming no interactive effects for any of the parameters yields the following less conservative results;

- ~a ,c (Eq. 2.3)

= 1.25 percent

- Thus the impact of the use of Equation 2.1 is even greater in the area of : rack ef f ects than f or the sensor. Therefore, accounting for inter-active ef f ects in the statistical treatment of these allowances insures a conservative result.

l 2.4 PROCESS ALLOWANCES Finally, the PMA a'nd PEA parameters are considered to be l'ndependent of both sensor and rack paramete'rs. PMA provides allowances for the non-instrument related effects, e.g., neutron flux, calorimetric power error

~

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assumptions, fluid density changes, and temperature stra.tification assumptions. PMA may consist of more than one independent error allow-ance. PEA accounts for errors due to metering devices, such as elbows and venturis. Thus, these parameters have'been statistically factored into Equation 2.1.

uuumuufdL5am 2-6

0 ,f WESTINGHOUSE PR'OPRIETARY CLASS 3 3.0 PROTECTION SYSTEM SETPOINT METH000 LOGY 3.1- MARGIN CALCULATION As-noted in Section One Westinghouse utilizes a statistical summation of the various components of the channel breakdown.. This approach is valid where no dependency is present. An arithmetic summation is requiredwhereaninteractionbetweentwopc{ametersexists,SectionTwo i

-provides a more detailed explanation of thisiapproach. The equation ,

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

~ (Eq. 3.1) where: .

TA-= Total Allowance, and

.all other parameters are as defined for Equation 2.1.

Tables 3-1 through 3-15 provide individual channel breakdown and. channel statistical allowance' calculations for all protection functions utiliz-ing 7300 process rack equipment. Table 3-16 provides a summary of the previous 15 tables and includes analysis and technical specification values, total allowance and margin.

3.2 OEFINITIONS FOR PROTECTION SYSTEM SETPOINT TOLERANCES To insure a clear understanding of the channel breakdown used in this report, the following definiti.ons are noted:

1. Trio Accuracy The tolerance :and containing ne nignest expec:ec value of the difference tetween (a) the cesired trip point value of a process a5550:10/013184 3-1

[-

WESTINGHOUSE PROPRIETARY CLASS 3 variaole and ;0) the actual value at wnich a comparator trips (and thus actuates some desired result).

This is the tolerance band, in percent of span, within which the complete channel must perform its intended trio f unction. It includes comparator setting accuracy, channel accuracy (including the sensor) for each input, and environ-mental effects on the rack-mounted electronics. It comprises all instrumentation errors; however, it does not include process heasurement accuracy.

2. Process Measurement Accuracy includes plant variable measurement errors up to but not including the sensor. Examples are the effect of fluid stratification on temperature measurements and the effect of changing fluid density on level measurements.

3. Actuation Accuracy Synonymous with trip accuracy, but used where the word " trip

• does not apply;

4. Indication Accuracy The tolerance band containing the highest expected value of the difference between (a) the value of a process variable read on an indicator or recorder and (b) the actual value of that process vari-It

• able. An indication must fall within this tolerance band.

includes channel accuracy, accuracy of readout devices, and rack environmental effects, but not process measurement accuracy (such as fluid stratification). It also assumes a controlled environment for the readout device.

5. Channel Accuracy The accuracy of an analcq :nannel ani:n inci Aes :ne ac:ura;j ;r tne primary element and/or transmitter and mccules in :ne cna'n wnere l

22 l a5550:10/013184

'. WESTINGHCUSE PROPRIETARY CLASS 3 caiitration of modules intermediate in a chain is allowed to com-censate for errors in other modules of the chain. Rack environ-mentaleffectsarenotinc{udedheretoavoidduplicationdueto dual inputs, however, normal environmental effects on field mounted hardware is included.

6' Sensor Allowable Deviation The accuracy that can be expected in the field. It includes drif t, temperature effects, field calibration and for the case of d/p

. transmitters, an allowance for the.effect of static pressure vari-ations.

The tolerances are as follows:

a. Reference (calibration) accuracy - [ ]+abc eccent unless other data indicates more inaccuracy. This accuracy is the SAMA reference accuracy as defined in SAMA standard PMC-20-1-1973(I) .

, b. Temperature effect - ( )+abc ercent based on.a nominal temperature coef ficient of ( )+abc percent /100*F and a maxi-mum assumed change of 50*F.

c. Pressure effect - usually calibrated out because pressure is constant. If not constant, nominal ( ]'*D' percent is used. Present data-indicates a static pressure effect,of approximately-( ]+8DC percent /1000 psi.

d. Orift - change in input-output relationship over a period of time at reference conditions (e.g., ( ]'

, )+abc of span).

(1) Scient'ific Accaratas Manuf acturers Associaticn, Standard PMC-20-1 'i973,

• Process Measurement and Control T e rm i n o l og y .

45550: 10/013194 3-3

. ,' WESTINGHOUSE PROPRIETARY CLASS 3

7. Rack aliewa:1e Sev'ation The tolerances are as follows:

a. Rack Calibration Accuracy The accuracy that can be expected during a calibration at reference conditions. This accuracy is the SAMA reference I) This accuracy as defined in SAMA standard PMC-20-1-1973 .

includes all modules in a rack and is a total of ( ]+abc percent of span assuming the chain of modules is tuned to this accuracy. For simple loops where a power supply (not used as a converter) is the only rack module, this accuracy may be

~

ignored. All rack modules individually must have a reference accuracy within ( )+abc ercent.

b. Rack Environmental Effects Includes effects of temperature, humidity,, voltage and frequency changes of which temperature is the most significant. An accuracy of ( )+abc ercent is used khich considers a nominal anbient temperature of 70*F with extremes to 40*F and 120*F for short periods of time. .

c. Rack Orif t (instrument channel drif t)' - change in input-output relationship over a period of time at reference concitions (e.g.,( )

)-il percent of span.

d. Comoarator Settino Accuracy Assuming an exact electronic input, (note that tne

• channel accuracy

• takes care of deviations fr0m this ideal), the toler-ance on the precisien with which a c0mparator trip value (1) Scientific accara:us Manufactureres Associa: ton, 5:ancard PMC-20-1-1973, ' Process Measurement anc C:n:rol Tecnnoicgy' j 8

e I WESTINGHOUSE PROPRIETARY CLASS 3 can ce set, within such practical constraints as time and ef fort expended in making tne setting.

The tolerances are as follows:

(a) Fixed setpoint with a single input - ( ]+abc eccent accuracy. This assumes that comparator non'inearities are compensated by the setpoint.

• 1 (b) Oual input - an additional ( ]+abc eccent must be added for comparator nonlinearities between two inputs.

Total ( ]+abc percent accuracy.

Note: The following four definitions are currently used-in the Standardized Technical Specifications (STS).

8. Nominal Safety System Setting .

f I

The desired setpoint for the variable. Initial calibration and subsequent recalibrations should be made at the nominal safety system setting (" Trip Setpoint" in STS).

l

9. .Limitino Safety System Setting A setting chosen to prevent exceeding a Safety Analysis Limit Violation of this setting represents  ;

(" Allowable Values

• in STS). l an STS violation.

10, Allowance for Instrument Channel Orift The difference between (8) and (9) taken in the conservative direction.

11. Safety Analvsis limit The setpoint value assumed in safety ana.tyses.

• 3-5 ]

4555Q: 10/013184 _

. LWESTINGHOUSE PROPRIETARY CLASS 3

12. Total Al' cwa 51e Setooint Deviation Same definition as 9, but the difference between 3 and 12 encom-passes [ }.

3.3 STATISTICAL METH000 LOGY CONCLUSION The Westinghouse setpoint methodology results in a value with a 95 per-

. cent probability with a hign confidence level . With the exception of Process- Measurement Accuracy, Rack' Orif t, and Sensor Orif t, all uncer-tainties assumed are the extremes of the ranges of the various parameters, i.e., are better than 2e values. Rack Orift and Sensor Drift are assumed, based on a survey of reported plant LERs, and with Process Measurement Accuracy are co.nsidered as conservative values.

e 9

b 4

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WESTINGHOUSE PROPRIETARY CLASS 3 4,'

TABLE 3-1 POWER RANGE,. NEUTRON FLUX - HIGH AND LOW SETPOINTS Allowance

• Parameter

.+ a,c - -+a, Process .easurement M Accuracy w

~

Primary Element Accuracy

• +a,c Sensor Calibration

}

(

Sensor Pressure Effects Sensor Temperature Ef f ects +a,c

)

(

+a,c Sensnr Orift '

1

. C .

Env;ronmental Allowance

~

• Rack Calibration ,

Rack Accuracy .

Comparator One input Rack Temperature Effects Rack Orift ,

• In percent span (120 percent Rated Thermal Power)

Channel Statistical Allowance = y 3-7 45550: 10/013194 - . _ . . _

. .-w-- ----------------------------------;---- -- - - -

. WESTINGHOUSE PROPRIETARY CLASS 3 TABLE 3-2 POWER RANGE, NEUTRON FLUX - HIGH POSITIVE RATE AND HIGH NEGATIVE RATE Parameter Allowance

• Process Measurement Accuracy . -a , c

- - +a , c Primary Element Accuracy i i

. 'a,c ',

Sensor Calibration '.

Sensor Pressure Effects Sensor Temperature Effects .

+a ,c Sensor Orift . +a,c Environmental Allowance .

4 Rack Calibration ,

Rack Accuracy Comparator One inpu't Rack Temperature Effects Rack Orift .

J 1

• In percent span (120 percent Rated Thermal Power)

Channel Statistical Allowance = ,

-a,c

~

45550:10/013184 3-0

p. ,. . .; . ..-:

+

WESTINGHOUSE PROPRIETARY CLASS 3 TABLE 3-3 INTERMEDIATE RANGE, NEUTRON FLUX Allowance

• Parameter Process Measurement Accuracy ,+a ,c

- - +a , c

. l Primary Element Accuracy

+a,c Sensor Calibration

)

(

Sensor Pressure Effects

- Sensor Temperature Effects +a,c

( l

+a,c Sensor Orift  :

3

(+ i l

Environmental Allowance Rack Calibration Rack Accuracy Comparator One input

• Rack Temperature Effects  !

1 Rack Drift i 5 percent of Rated Thermal Power - _i ,

l

• In percent span (conservatively assumed to be 120 percent Rated Thermal Power)

Channel Statistical Allowance = _a4 O

I l

4i59Q;10/013184 3-9  ;

7 '

3

, WESTINGHOUSE PROPRIETARY CLASS 3 TABLE 3-4 SOURCE RANGE, NEUTRCN FLUX Parameter Allowance

• Process Measurement Accuracy ,+a ,c

- - +a , c Primary Element Accuracy Sensor Calibration +a,c

( l Sensor Pressure Effects Sensor Temperature Effects +a,c

( l

' Sensor Orift +a.c ,

[ ]

Environmental Allowance Rack Calibration -

Rack Accuracy .

Comparator One input

. Rack Temperature Effects Rack Orift 3 x .104 cps

• In percent. span (1 x 106 counts per second)

Channel Stat.istical Allowance = .

• a ,c 45550: 10/013184 3-10

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WESTINGHOUSE PROPRIETARY CLASS 3

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TABLE 3-5 ,

.p.g-OVERTEi4PERATURE N-16 Allowance

• Parameter

+a , c,

- - +a,c, Process ideasurement Accuracy

.! e v

!(~ ,<

. ' t, y \

~

Primary Element Accuracy Sensor Calibration -

+a,c v44- ,

[

t, .-

Sensor Pressure Effects .

4 Sensor. Temperature Effacts <'

+a,c

(

• 1 A

v Sensor Orlft - .

+(7, +a , c

t. ,.

/,,

.g.

i ,. v f'

Environmental Allowance 4, '

Rack Calibration .

+a,c p -

y' e

(,

.(f

'( (l -

e I_ Q, . .

• I Rack Accuracy +a.c '

n.

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(

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.[h,  ;';l))] T TABLE 3-5 (Continued) a s.

[ 'N ' ' U 3 OVERTEMPERATURE N-16

.e , s.

Allowance

• p$ Aa rame tir v,8 - - +a,c

[(iD(Total Tej .

v pu' '((t ( Ty c '

( y! N-16 Pressure Channel

~Al Channel-Compa ra tor

,.Two inputs s

s t -

Ra'ck' Temperature Effects ( )+a,c t i -

33 **

~ Rack Orif t

/Setpoint reference signal f),i N-16 channel - .-

j i

( . ,,  %{s

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• ' * . WESTINGHOUSE PROPRIETARY CLASS 3 I

TABLE 3-6

)

. 0VERPO'AER N-16 Ny_

"" Allowance

• Parameter ,

+a,c Process Measurement Accuracy ta , c -

l l

Primary Element Accuracy

' Sensor- Ca l ib ra tion .+ a,c Sensor _Tamperature Effects +a,c

( )

Sensor Pressure Effects 1

Sensor Orift' .

.+a ,c Environmental. Allowance Rack' Calibration . +a ,c Rack Accuracy: 'a,c

[. ] .

Total Tc N-16

-Setpoint. l Comparator.

'Two inputs pa ,c Rack' Temperature Effects (

Rack Orift- ,

LSetuoint reference signal l' N-16 channel a n

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WESTINGHOUSE PROPRIETARY CLASS 3 r

TABLE 3-6 (Continued)

[, OVERPO'AER N-16

• In percent span (Tc - 120*F, N 150 percent Rated Thermal Power, AI.- t 60 percent AI)

• • See Table 3-18 f or conversion calculations Channel Statistical Allowance = la ,C B

6 0

'e 9

0 9

-  % 28

. WESTINGHOUSE PROPRIETARY CLASS 3 lAULL J-f PRESSURIZER PRESSURE - LCW AND HIGH, REACTOR TRIPS Sarameter Allowance

• _ ,,_ a , C Process Measurement Accuracy Primary Element Accuracy .

. Sensor Calibrat on Sensor Pressure ' Effects Sensor Temperature Effects -

+a , c Sensor Orift

. Low Pressure Trip High Pressure Trip (t'reated as a bias]+a,c Environmental Allowance Rack Calibration

-Rack Accuracy Comparator One input Rack Temperature Effects Rack Orift - _

• In percent span (800 psi)

• Channel Statistical Allowance = _ -a , e 45550: 10/051184 3-15

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• - WESTINGHOUSE PROPRIETARY CLASS 3 t.-

TABLE 3 8 PRESSURIZER WATER LEVEL - HIGH Parameter-Allowance

• _ +a ,c Process Measurement Accuracy' _

+a.c

[ .

3 Primary Element Accuracy Senso'r Calib' ration Sensor Pressure Effects-

' Sensor Temperature Effects Sensor Orift Environmental Allowance Rack Calibration-Rack Accuracy Comparator One input .

Rack Temperature Effects Rack Drift ; _ _

In percent span (100 percent span)

Channel Statistical Allowande = _ 'a ,c 45550:10/051184 3-16.

. . =; .. . .

. . - 7, . . ... .

. WESTINGHOUSE PROPRIETARY CLASS 3 TABLE 3-9 LOSS OF FLOW Parameter Allowance

• _ *a ,c Process Measurement Accuracy (

]+a,c Primary Element Accuracy

+a,C  ;

-( l

~

Sensor Calibration +a,c

(- ]

Sensor Pressure Effects .+a,c

( ] j 1

Sensor Temperature Effects (I 2+a,c Sensor Orift [ ]+a,c r

Envi'ronmental Allowance Rack Calibration Rack Accuracy ( ]+a,c ,

Compa ra tor-Oneinput( ]+a .C Rack Temperature Effects [ ]+a,c Rack Orift'

1.0 percent AP Span _ _

In percent flow span (120 percent Thermal Design Flow)

'** See Table 3-23 for explanation

_'a ,c l- ,

Channel-Statistical Allowance = ,

p l r

d t

45550: 10/051124,.

[- ---

sus ,_

-. WESTINGHOUSE PROPRIETARY CLASS 3 .

t.

TABLE 3-10a STEAM GENERATOR WATER LEVEL - LOW-LOW UNIT 1 (04) c Allowance

• Pa rame te r Process Measur'ement Accuracy Density variations with load due to changes _

_ *a,c in ' recirculation **

-( l ,

3+a,c

- Primary Element Accuracy

, Sensor Calibration Sensor Pressure Effects Sensor Temperature Effects

]+a,c

[

Sensor Orift Environmental Allowance Reference leg Heatup Rack Calibration -

Rack Accuracy Comparator

's One input Rack Temperature Effec'ts Rack Orift -

• In percent span (100 percent span)

. ** _See Table 3-19 for explanation

(

3+a,c

- -a.c i

Channel Statistical Allowance =

4 m

Q&_a

WESTINGHOUSE PROPRIETARY CLAS' 3 TABLE 3-10b STEAM GENERATOR WATER LEVEL - LOW-LOW UNIT 2 (35)

Pa rame t e r Allowance

• Process Measurement Accuracy

_+a ,c Density variations with load due to changes _

in recirculation **

Primary Element Accuracy Sensor Calibration Sensor Pressure Effects .

Sensor T.emperature Effects Sensor Drift Environmental Allowance Reference Leq Heatup Rack Calibration Rack Accuracy

-Comparator One input'

' Rack Temperature Effects Rack Orift. _ _,

• In percent span (100 percent span)

. ** See -Table 3-19 f or explanation Channel-Statistical Allowance =

,a + ,c 45550,: 10/013184 3-19

..,' WESTINGHOUSE PROPRIETARY CLASS 3 TABLE 3-11 CONTAINMENT PRESSURE - HIGH, HIGH-HIGH, HIGH-HIGH-HIGH

.. Span - 65 psi Allowance

• parameter

_ _ +a,c Process Measurement Accuracy Primary Element Accuracy

. Sensor Calibration Sensor Pressure Effects Sensor Temperature Effects Sensor Drift Environmental Allowance Rack Calibration Rack. Accuracy ,

Comparator ,

One. input .

Rack Temperature Effects Rack Drift 0.65 psig i

• In percent span (65 psig)

Channel Statistical Allowance =

~

+a,c l

45550:10/013184 3-20 L

.' WESTINGHOUSE PROPRIETARY CLASS 3 TABLE 3-12 PRESSURIZER. PRESSURE - LOW, SAFETY INJECTION pa rame t e r Allowance

• _ 'a ,c Process Measurement Accuracy Primary Element Accuracy I

SbnsorCalibration .

~

Sensor Pressure Effects Sensor Temperature Effects Sensor Drift Environmental Allowance Rack Calibration ~

Rack Accuracy Comparator One input Rack Temperature Effects Rack Orfft _ _

• In percent span (800 psi)

Channel Statistical Allowance = - *a ,c 3-21 45550 10/050184

7, f 4- h' WESTINGHOUSE PROPRIETARY CLASS 3 TABLE 3-13 STEAMLINE PRESSURE - LOW Pa ramete r A_llcwance*

_ _. +a.C

-Process-Measurement Accuracy Primary Element Accuracy i '

Sensor Calibration

' Sensor Pressure Effects Sensor Temperature Effects Sensor Drift Environmental Allowance Rack Calibration

~ Rack Accuracy Comparator '

One input Rack Temperature Effects- ,

Rack Orift ,_.

s

• In percent span'(1300 psig)

Channel Statistical Allowance = ,

+3,c 4

4 m

..^'

• WESTINGHOUSE PROPRIETARY CLASS 3 TABLE 3-14

. NEGATIVE STEAMLINE PRESSURE RATE - HIGH

-Parameter- ~ , Allowance *

+a , C Process Measurement Accuracy Primary Element Accuracy ,

. +a ,c Sen.sor Calibration

.iensor Pressure Effects

. +a,c Seqsor Temperature Ef f ects

. +a ,c Sensor Drift Environmental Allowance Rack Calibration Rack Accuracy-Comparator One input Rack. Temperature Effects

' Rack Drift - _

• In percent span (200 psig)

Channel Statistical Allowance = .'a,C l

l 3-23 b- - 55550:10/013184- ~ - - . - - - . . ____ _.

i r:. - .

WESTINGHOUSE PROPRIETARY CLASS 3 ,

l l

TABLE 3-15a STEAM GENERATOR WATER LEVEL - HIGH-HIGH UNIT 1 (04)

Pa rame te r Allowance

• Process' Measurement Accuracy-

_ . -a , c j density variations with load due to changes -

"in recirculation ** +a,c l I

l l

Primary Element Accuracy Sensor Calibration Sensor Pressure Effects Sensor Temperature Effects Sensor Orift Environmental Allowance Rack Calibration i

-Rack Accuracy Comparator One input Rack Temperature. Effects Rack Orift

• • In percent span (100 percent span) l

• • See Table 3-19 for explanation Channel Statistical Allowance =

. +a ,c l

45550:10/013134 3-Za

)

1 s s' e

. WESTINGHOUSE PROPRIETARY CLASS 3 .

TABLE 3-15b STEAM GENERATOR WATER LEVEL - HIGH-HIGH UNIT 2 (05)

Allowance

• Parameter Process Measurement Accuracy - -

'a , c density variations with load due to changes.

in recirculation""

Primary Element. Accuracy Sensor Calibration Sensor Pressure Effects Sensor Temperature Effects

. Sensor Orift Environmental Allowance Rack Calibration Rack Accuracy Comparator One input .

. Rack Temper'ature Effects Rack Orfft - _

• I'n percent span (100 percent span)

• • See Table 3-19 for explanation Channel Statistical Allowance = . + a,c

~

' 3-25 45550:10/013184

s  ;

e t l

DOCUV1ENT ~

~

l

~

PAGE .

l PU_ LED l ANO.sewa J NO. OF PAGES .

l

)

l REASON l

C PAGE ILLEGS.E. .

1 D HARD CDPV FJLED A1. PDR CF l o men :  ;

i -

1 3 l l D BETTER COP (REQUE51ED ON _

E 10 FILM.

CDPr FILED A1: PDR .

, OTHER -

O ,

D FILMED ON APERTURE CARD NO 4

l  :

. ,' WESTINGHOUSE PROPRIETARY CLASS 3 TABLE 3-17 OVERTEMPERATURE N-16 1 + T)S .

OT Ib N<- K 1

-K 2 1+T 5 2 T

c

-T c

+X 3 (M) - f (W3 wnere:

16 1+t S\ l OT N= S 4

1 (1+T2/

I j j h[ 1

+K55 c c} '16 91*K8 ~7 1 +1 3

5 I+T 4 j V + '5 S

)

6 II-9) 1 I 16 N= N PWR - Kg N) - K10"2 N), N 2 = utputs of top sections of excores nem percent RTP K = 1.069 g

X

.( )+a,c percent RTP K = 0.00948 1/ percent.RTP *F 2 . .

K = 0.000494 1/ percent RTP -psi 3

Vessel AT = 618.2-558.8*F = 59.4*F positive f(at) gain = 1.55 percent RTP/ percent al a , c.

I 45550 30/050294 3-27

^ *

., WESTINGHOUSE PROPRIETARY CLASS 3 TABLE 3-17 (Continued)

GVERTEMPERATURE'.'l-16 GAIN AND CONVERSION CALCULATIONS

-a,C

~

e t

9 e

8 m

0 1

i W

~

. WESTINGHOUSE PROPRIETARY CLASS 3 TABLE 3-18 OVERPOW5'R N-16 CONVER$[CN CALCULATIONS 6

OP N1K 4 -f2 (6l) where: ,

i, e .

16 N=

!1 + '1S\

OP

) ,*2S/ 1 I

) ) )

h I

, I+X5 ( c' c 16 I

41" 8 7 \1 + t 3 5 1+1 54 1+t 5 /)

I +

6 (I ~ 4 )

1 l 6

N= N PWR - K g N) -K10"2 N), N 2 = utputs of top sections of excores K =[ ]#'

nom K = 1.12 4

Vessel 6T = 59.4*F 1 percent RTP = 0.59'F ~ 0.6 *F f (6t) "

2 , "a 9

. WESTINGHOUSE PROPRIETARY CLASS 3 TABLE 3-18 (Continued)

OVERPCWER .'J-l6 CONVERSION CALCULATIONS

+a,c 45550: 10/013184 3-30

+ WESTINGHOUSE PROPRIETARY CLASS 3 TABLE 3-19 STEAM GENERATOR LEVEL DENSITY VARIATIONS Because of density variations with load due t changes in recirculation, it is impossible without some form of compensation to have the same

- accuracy'under all load conditions. In the past the recommended calibra-tion has been at 50 percent power conditions. Approximate errors at 0 percent and 100 percent water. level readings'and also for ncminal trip points of 10 percent and 70 percent level are listed below for a typical 50 percent power conditio'n calibration. This is a general case and will cnange somewhat from plant to plant. -These errors are only from density changes and do not reflect channel accuracies, trip accuracies or indi-

• cated accuracies which has been defined as a aP measurement only.I )

INDICATED LEVEL (50 Percent Power Calibration) ,

10 70 100 .

0 percent ' percent percent percent  ;

~

_'s,c t

t (1) Miller, R. S. ,

• Accuracy Analysis f or Protection /Saf eguards and

' Selected Control Channels", WCAP-3108 (Proprietary). Mar:n 1973.

3-31 NOMIS4 _ . _ _ _ _ _ --- - _ . . . _ _ . _ . . _ _ _ _

-* WESTINGHOUSE PROPRIETARY CLASS 3 .

e TABLE 3-20 aP MEASUSEMENTS EXPRESSED IN FLOW UNITS

~ The AP accuracy expressed as percent of span of the transmitter applies throughout the measured span, i.e., t 1.5 percent of 100 inches aP = t 1.5 inches anywhere in the span. Because F = f(aP) 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:

i a

c 3-32 45550: 10/051684

c- .

- WESTINGHOUSE PROPRIETARY CLASS 3 Error in flow units is: +a ,i Equation 3-20.8 is used to express errors in percent full span in this document.

6

m -

.=:.--

.WESTIFFIriOUSE PROPRIETARY CLASS 3 TABLE 3-21

• Tav'g - LOW, LOW-LOW Parameter-

~

Allowance

• 1 Process Measurement Accuracy -

'a ,c

• a , c a

f Primary Element Accuracy ,

Sensor Calibration

. +a,c Sensor Pressure Effects b

- S'ensor Temperature Effects- +a ,c

{.-

}

' Sensor Orift . *a,c -

Environmental Allowance _ _

t l

L ._ w

.- , WESTINGHOUSE PROPRIETARY CLASS 3 .

. TABLE 3-21 (Continued)

Tavg.- LOW, LOW-LOW Parameter - Allowance

• Rack Calibration' d 'C _ +a ,c Rack Accuracy

- +a,c

(. 3

. Total C1 Cl N-16 Comparator'

.One input Rack Temperature Effects

[ 3

' Rack Drift

. 'N-16 Channel

'T Channel

• In percent span (T - 120*F, N 150 percent Rated Thermal Power, al - +.'60 percent 61,'Tjyg - 100*F)

• • See Tacle 3-22 for gain / conversion calculations 45550: 10/013184 3-35

c .

, WESTINGHCUSE PROPRIETARY CLASS 3 TABLE 3-21 (Continued)

Tavg - LOW, LOW-1.CW Channel Statistical Allowance = -a,c

~

9 m

G b

o

~ -

1, . . ,

. WESTINGHOUSE PROPRIETARY CLASS 3 -

TABLE 3-22 T - LOW, LOW-LOW N-16 GAIN CALCULATIONS AVG _

= T + N

. T, 3

/ 1 h 16 9

=

1 + t)S j 1 N

3 k 1 1 1 / I+K5 (T -c T )c > 16

[1

( +t I-

~

'91 : "

8 . 7 3 / \

I

• • 4 $ / [I +'

\

b 5I i /I+ 6 II~4 ) 1 N = '. N Pwr. - Kg N) -K10"2 N),-Ng=outputsoftopsectionsofexcores vessel ai = 618.2 558.8'F = 59.4*F 100~ percent RTP = 60*F 1 ~ percent RTP = .0.6*F' or l'F = 1.7 percent RTP

_ta,c-x x

2 -45550': 10/051.184 3

~*

. WESTINGHOUSE PROPRIETARY CLASS 3 TABLE 3-22 (Continued)

T - LOW, LOW-LOW N-16 GAIN CALCULATIONS

_ 'a ,c e

M e

4 e

e r

2 l uwvaduuaL9ukVt 3-23

m. - .

7.,7 ,,

,' WESTINGHOUSE PROPRIETARY CLASS 3 ty1 / [i (,

5.'

~~

'[ i ,4 ?

i TABLE 3-23 [

t A.,

,. ..,. , . !j

ff -  %' PRECISION FLOW MEASUREMENT

.(D 1

7

• Allowance *

-}y! , Parameter 3: ,

- ~

'a,c j'th:*n,- ;g Pressurizer bressure uncertainty (

/ ( } +g'c on c9 d leg specific volume 1

- t e; 5

( j ,

e,..

Pressurizer,. pressure uncertainty (

, ~

T ]+"'" on hot leg specific volume

~)if {

Jf 3 T uncertainty [ ]+a,c on cold leg

, e

~ ':- specific volume. ,

Iw ,

e , g' f, )

Tg -unc'er'tainty-[ - ]** on hot leg ,

sp'er.ific volume .

"? i

~

c, < :

f;;

. +a .C

• f 3, - -Uncertainty on hot leg,plumetric flod e{p 1

t

c. , s ,

~

'i '

, f'

Q 3;,,o

.qJT? ; ( j,S) ) f;. t ,, .

W'l r , Hot' leg jolumetric flow uhcertainty on h'ot' leg specific +a C volume L- t r rd .

< c.- << \

r g ,

vc . cq , e4 ,-r f ,

.-Y..c . Precision calorimetric-loop power uncertainty onu +a,c .

hot leg specific volume

,/

'lf;, p

- y ,! ' \ /

s v .r . 5 s. , $

Procedure convergence ,derer on loop power

(- '

, impact on ho-t Ieg, F'- [ ( _]

.t F

'T ,

specific vol6me  ;'

• y[;;y

JQ s m , ,

m .

-In percent flow o'

s. .

' ~

. WESTINGHCUSE PROPRIETARY CLASS 3

h ,a >

q+

i i TABLE 3-23 (Continued) 9' s? , .

't

,, t -

PRECISION FLOW MEASUREMENT i.

~

/A 4

, Channel Statistical Allowance =

-a,C f,' l 0-

,) .

4\ '

\

git -

c ., t s, I

k'

~

I5 1

." I

/t

/

f,'~,

k s

e

'y 9

e

• 's

~

y, mn e_w 1 -40

-m-c -

, i

' WESTINGHOUSE PROPRIETARY CLASS 3 TABLE 3-24 RWST LEVEL '- AUTOMATIC SWITCHOVER Allowance

• l Pa rameter

_ *a ,c  ;

i Process-' Measurement Accuracy

. . Primary Element Accuracy-Sensor Calibration Sensor Pressure Effects

~

Sensor Temperature-Effects

-Sensor Orift -

l Environmental Allowance Rack Calibration Rack Accuracy

'Comparator-One-Input l

. Rack' Temperature Effects l Rack 0 rift

~

1 1

"In percent span (100 percent ap)

~wouvastsuuw -3 21-

.- WESTINGHCUSE PROPRIETARY CLASS 3 TABLE 3-24 (Continued)

RWST LE'/EL e AUTOMATIC SWITCH 0'!ER Channel Statistical Allowance = _ 'a ,c .

i.

See e

M h

3 - 12

<-- est%th1Rffi31#14

~

. ,' 'dESTINGHOUSE PROPRIETARY CLASS 3 1

a.0 TECHNICAL SPECIFICATION USAGE 4.1 CURRENT USE_

The Standardized Technical Specifications (STS) as used for Westinghouse type plant designs (see NUREG-0452, Revision 4) utilizes a two column format for the RPS and ESF system. This format recognizes that the setpoint channel breakdown, as presented in Figure 4-1, allows for a certain amount of rack drift. The intent of this format is to reduce the number of Licensee Event Reports (LERs) in the area of instrumenta-tion setpoint drift. It appears that this approach has been succassful in achieving its goal. However, the approach utilized is fairly sim-plistic (

)+a,c

• The use of the statistical summation technique described in Section 2 of this report allows for a natural extension of the two column approach.

(

+a,c and allows for a more flexible approach in report-j ing Leas. Also of significant benefit to the plant is the incorporation of sensor drift parameters on an 18 mcnth basis (or more often if neces-sary). .

1 l

4-1 45550:10/013184

v. .

J. WESTINGHOUSE PROPRIETARY CLASS 3 4.2 WESTINGHOUSE STATISTICAL SETPOINT METHODOLOGY FOR STS SETPOINTS Recogniti.ng that besides rack drift the plant also experiences sensor

-drift, a different approach to techi n cal specification setpoints, that is somewhat more sophisticated, is used today. This methodology accounts for two additional factors seen in the plant during period'ic surveillance, 1) interactive effects for both sensors and rack and, 2) sensor drift effects.

4.2.1 RACK ALLOWANCE When an The first item that will be covered is the interactive effects.

instrument technician looks for [ ]* he is seeing more than that. This interaction has been noted several times and is handled in Equations 2.1 and 3.1 [

)+a,c .

To provide a conservative'" trigger value", the di.ffer-ence between the STS trip setpoint and the STS allowable value is ,

determined by two methods. The first is simply the values used in the a

).+a,c The second

(

[

]&a,c as_follows:

]+a,c ,(gq, 4,3)

[

S where:

+a,c d

m

" WESTINGHOUSE PROPRIETARY CLASS 3 s -. ..

_ -a , c

~ .

-The smaller of the trigger values should be used for comparison with the "as measured * ( ]+" value. As long as the "as mea-sured" value is smaller, the channel is well within the accuracy allowance. If the "as measured" value exceeds the " trigger val.e", the actual numbers should be used in the calculation described in Section 4.2.3.

This.means' that all the instrument technician has to do during ti '31

. day periodic surveillance is determine the value of the bistable . rip

.setpoint, verify that it is less than the STS Allowable Value, and does

not have to account for any additional ef fects. The same approach is used f or the sensor, i.e., the "as measured" value is used when required. Tables 4-1 and 4-2. show- the current STS setpoint philosophy (NUREG-0452, Revision 4) and the Westinghouse rack allowance-(for use on 31 day surveillance only). A comparison of the two different Allowable LValues'will' snow the. net gain of the Westin^ghouse version.

4.2.2 INCLUSION OF "AS MEASURE 0" SENSOR ALLOWANCE If'the approach used by Westinghouse was a straight arithmetic sum, sensor allowances for drif t would also be straight .forsard, i.e., a

" three column setpoint methodology. However, the use of the statistical summation requires a somewhat more complicated approach. This method-ology; as. demonstrated in Sectier 4.2.3, Implementation, can be used quite readily by any operator whose plant's setpoints are based on sta-

.tistical summation. The methodoiogy is based on the use of the follow-ing equation.

4-3

! - L45550:10/013184

i _ ,,

• ^

M~ e f. WESTINGHOUSE- PROPRIETARY ' CLASS 3

~

]+a,c (Ec. 4.2)

(-

L wnere:

R- = theas-measured rack value" ( ]***C S' = the 'as measured sensor value* ( ]+a,c and all other. parameters are'as defined in Equation 4.1.

Equation 4.2.can be reduced further, for use in the STS to: .

%y 1

(Eq. 4.3)

Z + R + S'1 TA

'%here:

[_ 3+a,c Equation 4.3 would be used'in two instances, 1) when the "as measured" rack:setpoint value exceeds the rack " trigger value* as defined by the

- STS Allowable Value, and, 2) when determining that the "as measured" sensor value is within acceptable values as utilized in the various Saf ety Analyses and verified every 18 months.

4.2.3 IMPLEMENTATION OF THE WESTINGHOUSE SETPOINT METH000 LOGY Implementation of this methodology is reasonably straight forward.

Appendix A provides_a text and tables for use in the Technical Specifications. An example of how the specification would be used for

.the Pressurizer Water Level - High reactor trip li as folicws.

Every 31 days, as required by Table 4.3-1 of NUREG-0452, Revision 4, a f unctional _ test would be ;:erformed on the channels of this trip func-tion. During this test the bistable trit setsoint would De determined e

i-

r~ .

' - WESTINGHOUSE PROPRIETARY CLASS 3 for eacn nannel. If the as measured" bistable trip setpoint error was founc to :e less than or equal to that required by the Allowable value, no action would be necessary by th.e plant staff. The Allowable Value is cetermined by Equation 4.1 as f'ollows:

_ 'a ,C I .

TA = 5 percent (an assumed value)-

+a,C 5

4

^ However, since only (

),+a,c that value will be used'as the " trigger value". The lowest of two values is used.for the " trigger value*; (

1.+a,c

ri  ; .

.. . WESTINGHOUSE PROPRIETARY CIJtSS 3 Now assume that one bistable has " drifted

• more than that allowed by the STS for 31 day surveillance. According to ACTION statement A , the plant staf f must verif y that Eqyation 2.2-1 is met. Going to Table 2.2-1, the following values are' noted: Z = 2.18 and the Total Allowance

.(TA) = 5.0. Assume that the "as measured" rack.setpoint value is 2.25 percent low and the "as measured" sensor value is 1.5 percent. Equation 2.2-1 looks like:

i Z + R + S 5 TA ,

2.18 + 2.25 + 1.5 15.0 .

5.9)5.0 As can be seen, 5.9 percent is not less than 5.0 percent thus, the plant staff'must follow ACTION statement *S" (declare channel inoperable and place in the " tripped" condition). It should be noted that if the plant staff had not measured the sensor drift, but instead used the value of S in Table 2.2-1 then the sum of Z + R + S would also be greater than 5.0 percent. In fact, almost anytime'the "as measured" value for rack drift is greater than T (the " trigger value"), use of .5 in Table 2.2-1 will result in the sum of I + R + 5 being greater than TA and requiring the reporting-of the case to the NRC.

If the sum of R + S was about one percent less, e.g. , R = 2.0 percent, S = 0.75 percent thus, R + S = 2.75 percent, then the sum of Z + R

• S would be less than 0 sercent. Under this condition, the plant staff would recalibrate the instrumentation, as good engineering practice l-suggests, but the incident is not reportable, even though the trigger value" is exceeded, because Equation 2.2-1 was satisfied.

In the determination of T for a function with multiple channel inputs there is a slight disagreement between Westinghouse proposed methodology 1

' and NRC approved methodology. Westingnouse believes that i should be either:

4-6 45550: 10/013134

n- ,

. . - z, *f WESTINGHOUSE PROPRIETARY 2JLSS 3 s

. '3,C (Eq. 4.4)

(Eq. 4.5)

.where:the subscript I and 2 denote c hannel s .1 and 2, and the'value of T

, used is-whichever is smaller.

The-NRC in turn'has_ approved a method of determining T for a multiple

-' channel input function as follows, either: ' ~

- +a,c (Eq. 4.6)

This method is Again the value of T used is whichever is smaller.

Ldescribed.in appropriately circumspect terms in NUREG-0717 Supplement 4,

- dated August 1982.

An example demonstrating all of the above noted equations for Overpower

N-16 is provided below:

- +a,C O

. t'

,+ a,C -

ED 1 -

4_7

WESTINGHOUSE PROPRIETARY CLASS 3

-a,c The value of T used is from Equation 4.5. In this document Equations 4.5 and 4.6, whichever results in the smaller value is used f or multiple channel input functions to remain consistent with current NRC approved mett}odologies. Table 4-3 notes the values of TA, A, S, T, and I for all

~

protection functions and is utilized in the determination of the Illowable Values noted in Appendix A.

l Table 4.3-1 also requires that a calibration be perf ormed every ref uel-ing (approximately 18 months). To satisfy this requirement, the plant staff would determine the bistable trip setpoint (thus, determining the "as measured" rack value at that time) and the sensor "as measured"

• value. Taking these two "as measured

• values and using Equation 2.2-1 again the plant, staff can determine that the tested channel is in fact within the Safety Analysis allcwance.

4.3 CONCt.USION Using the above methodology, the plant gains added operational flexibil-ity and jet remains within the all:wances accounted for in tie various 455s0:10/051184 ,.

.. x. .< .~... . . ~

i

• WESTINGHOUSE PROPRIETARY CLASS 2

+ .

1 acc' cent analyses. In addition, the methodology allows for a senscr drif t f actor and an increased rack drif t f actor. These two gains should significantly reduce the proolems associated with channel drif t and thus, decrease the nu:cer of LERS while allowing plant operation in a safe manner.

l l

1 1

i l

l l

4-9 45550: 10/013184

, ., WESTINGHOUSE PROPRIETARY CLASS 3 0._'_

gij TABLE 4-1 EXAMPLES OF CURR'ENT STS SETPOINT PHILOSOPHY y

Power Range Pressurizer Neutron Flux - High Pressure - High Safety Analysis Limit 118 percent 2410 psig STS Allowable Value- 110 percent 2395 psig >

STS Trip Setpoint 109 percent 2385 psig TABLE 4-2 EXAMPLES OF~ WESTINGHOUSE STS RACX ALLOWANCE Power Range Pressurizer

• Neutron Flux - High Pressure - high 2410 psig Safety Analysis Limit 118 percent 111.2 percent 2396 psig STS Allowable value

• (Trigger value) t

- STS Trip Setpoint_ 109 percent 2385 psig i

f 4-10 45550:10/013184 _ . _ _ _ _ ,_ .. _ _ _--.- _ _ - . _ --_ .~ _ _ , _ _ _ _ . _ _ _ . _ . - _ .

~*

-*- ' WESTINGHOUSE PROPRIETARY CLASS 3 Safety Analysis Limit Process Measurement Accuracy A

Primary Element Accuracy Sensor Temperature Effects Sensor Pressure Effects Sensor Calibration Accuracy

'. Sensor Orift Environmer.tal Allowance Rack Temperature Effects

~

Rack Comparator Setting Accuracy Rack Calibration Accuracy STS Allowable Value Rack Orift STS Trip Setpoint -

Actual Calibration Setpoiht- -

Figure 4-1 NUREG-0452 Rev 4 Setpoint Error Breakdown 1

1.

4-11 L 45550: 10/013134

t . . , . , _-;

.L .i.

• WESTINGHOUSE PROPRIETARY CLASS 3

Saf ety -Analysis !.imit Process Measurement Accuracy Primary Element Accuracy

- Sensor Temperature E'ffects

- Sensor Pressure Effects Sensor. Calibration Accuracy 1SensorOrift '

Environmental Allowance Rack Temperature Effects STS Allowable Value Rack Ccmparator Setting Accuracy Rack Calibration Accuracy STS Trip Setpoint Figure 4-2 Westinghouse STS Set;oint Error Breakdoon

I I

. l l

I t

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PU_ LED

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NO. OF PAGES i  !

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! O PAGE ILLEGS2. .

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D HARD COPt FEED A1. PDR own- -

3 3  !

l D BETTER COP / REQUESTED ON

- t AGE 100 E10 FEM.

~

OICP(FEED A1: PDR . f l

CT4R D FEMED ON APERTURE CARD NO -

ObOINI

~

- WESTINGHOUSE PROPRIETARY CLASS 3 APPENDIX A SAMPLE COMANCHE PEAK i

SETPOINT TECHNICAL SPECIFICATIONS h

Y ,' ' WESTINGHCUSE PROPRIETARY CLASS 3 SAFETY LIMITS' AND LIMITING SAFETY SYSTEM SETTINGS 2.2 ' LIMITING SAFETY SYSTEM SETITINGS

, REACTOR TRIP SYSTEM INSTRUMENTATION SETPOINTS 2.2.1 The reactor trip system instrumentation and interlocks shall be

. consistent with the Trip Setpoint values shown in Table 2.2-1.

APPLICABILITY: As shown for each channel-in Table 3.3-1.

ACTION:

a'. With'a reactor trip system instrumentation or interlock setpoint less conservative than the value shown in the Trip Setpoint column of: Table 2.2-1. adjust the setpoint consistent with the Trip Setpoint value,

b. ~Withf the reactor trip system in's trumentation or interlock setpoint less conservative t'han the value shown in the Allowable Values

' column of Table 2.2-l', place the channel in the tripped condition within l-hour, and within the following 12 hours1.388889e-4 days <br />0.00333 hours <br />1.984127e-5 weeks <br />4.566e-6 months <br /> either: .

1. Determine that Equation 2.2-1 was satisfied for the affected channel and adjust the setpoint consistent with the Trip Setpoint value of Table 2.2-1, or Declare the channel inoperable and apply the applicable ACTION 2.

statement requirement of Specification 3.3.1 until the channel is restored to OPERABLE status with its setpoint adjusted consistent'with the Trip-Setpoint.value.

EQUATION 2.2-1 Z

• R

• S 5 TA 45550:10/012184 ,

A-2' -

ga ,-

E . ;. WESTINGHOUSE PROPRIETARY CLASS 3 '

.wnere:

Z: = The value for column Z,of Table 2.2-1 for the affected channel, R' =- the as measured" value '(in percent span) of rack error for the affected channel,

S = ~ either the "as measured" value (in percent span) of the-sensor

' error, or the value in column S of Table 2.2-1 for the affected

• . channel, and TA = the value from column TA of Table 2.2-l for the affected channel.

ii l

F i

A-3 45550: 10/013184

~ . . . . . , . . - _ . - , , . - , - . _ - - - . - - . - , _ - - , , , . - . . . - . . . - - . . - - - - - - . - . - ,

a

~ .

TABLE 2.2-1 REACIOR 1 RIP SYSTEM INSTRUMENTA110N TRIP SETPOINTS Total Sensor fun (tional unit Allowance (TAL _7_ Drift (51 Trio Setpoint Allowable Value NA NA

1. Manual Reactor Trip NA NA NA

2. Power Range, Neutron Flux, 7.5 4.56 0 $ 109% of RTP $ 111.2% of RIP liigh Setpoint C E3 Low Setpoint 8.3 .4.56 0 1 25% of RTP $ 27.2% of RIP g 5

rc

3. Power Range, Neutron flux, 1.6 0.5 0 $ 5% of RTP with a time 5 6.3% of RIP with'a liigh Positive Rate constant t 2 seconds constant t 2 seconds hm 5~6.3% of RIP with a u Power Hange, Neutron. Flux, 1.6 0.5 0 5 5% of RTP with a time 4.

liigh flegative Rate constant t 2 seconds constant 1 2 seconds {

o 8.4 0 i 31% of RTP m 17.0 5 25% of RTP

5. Intermediate Range, neutron flux (s 17.0 10.0 0 1 105 cps i 1.4 x 105 cps p

b. Sour (e Hange, Neutron Flux D

Overt emperature N-16 6.4 4.71 0.6&1.2 See note 1 See note 2 to

1. w 11 . Overpower N-16

~

4.0 1.91 1.3 5 112% RIP 5 114.5% RIP Pr e,surizer Pressure - Low 8.8 2.81 1.5 t 1910 psig

~

1 1896 psig 9.

10. Pre,surizer Pressure - liigh 7.5 4.96 0.5 5 2385 psig 5 2399 psig II. Pressurizer Water Level-liigh 5.0 2.18 1.5 $ 92% of instrument span 5 93.8% of instrument span l.31 0.6 1 90% of loop design > 88.8% of loop design

12. tou iteattor Coolant flow 2.5 flow

• flow" atoop de,ign iIow = 95.700 gpm COMAt"llf t PI'AK - (IN!! I .

A-4 A M W il4

a

^

TABLE 2.2'l (Continued)

REAC10R 1 RIP SYSlEM INSTRUNENTA110N TRIP'SETrolNIS Total Sensor l unc_dorial Unit Allowance (TA) 7 .Orift (S) Trip Setpoint Allowable Value

13. a . Steam Generator Water 8.8 7.08 .l.5 2 43.4% of narrow range. > 42.1% of narrow Ievel - tow-tow Unit'1 . instrument span instrument span 1 19.4% of narrow' range 2 11.11% of narTow

b. Steam Generator Water 19.4 17.38 1.5 s.

Ievel - Low-Low Unit 2 -

instrument span instrument span' D d'

14. tindervoltage - Reactor 7.7 0 0 1 4830 Volts 4781 volts E Coolant Pump 5 a

.- -g M

15. 11nderfrequency - Reactor 4.4 0 0 t 57.2_liz 57.1 ilz '

Coolant Pumps @

16. lus tiine trip $

m

A. tou trip System Pressure Not Westinghouse Scope

! L1. lushine Stop Valve Closure Not Westinghouse Scope h s

)1. Lilety injection Input NA NA NA NA NA p I rom I$1' g

en W

Ill. Itear tur Irip System 1

Interlocks i

a. Intermediate Range NA NA NA nominal lx10-10 amps 16x10-II amps j fleut on I lux, P-6

b. Iou Power Reactor isIps lilock, P-7 NA NA NA nominal 10 percent of < 12.2 percent of I) P-10 loput Rated lhermal Power Rated Thermal Power CUMAt4Clit PiAK - UNil 1 A-5 .

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}

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l p e ph eh p e b el T pl el l sa a

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rsv r r rsv S t el i el el el i I n puu pa pa puu N i pq m m pq c I o 0mE 8 r 0 r 0mE O p 1 I 4 e 1 e 1 I P t e h h e ~

T e l er l T l T l er )

S anu a a anu c E

nd nd nis 1 e

) S p

nis i e i b s r d i b s i e u e P i mr e mt mt oa mre our A A s u I r our oa N s n R T nTP nR nR nl P N e i 1 S S r t 2 r p n N ) i e g

o O S w C I ( + + o n

( T r

• P i f3 A ot I 1 t -

T sf l a A 1 N ni A A A a r

- E er A A A m e SD N N N N N r p

'2 M N ' 2 U K e o 2 R h T T l E S a L N A A A A j d n B I 7 A A K e i N N N N N N m A t I M = a o L ) R d n I A t i S T n f t s S Y ( i

• a p C S o R e p . , _

P c t e I e d I n A A A e r r e R a A A A s u e u t N N N N N N c s a I l w t ao p a n s c R tl i r e e i 0 ol r e r r dp n 1 T A t p e C m f i A 0 e er re (

E 1 r N t z g R - e g , i i P b -

e r s m r l f

• u p n , a e 4 s o rx h s

t n d s 5 r eu C r I e l 8 e 3 t wl e r o 5 r 2 u of e d u C 5 P 2 1 t e P s3 k u N n l 1 a n t p t o u - e a a 1 e nr pP r r 1 t n g it m B p e 4 1

i I p l n nu ou i .

p i

r m -

it 3 a - pe e e e -

4 1 RP t n er i r

t r '

l e nu ci

't t r e K P r , S e i s I

• A a ex g bs i l i e h P P n wn r o v w I I n wu s l oa r e ur o t

at O l' i ) t t 2 PI I R T P t m l oL c

m l

( a t c  : l n uo C u . . . e 1 N

f C d e R Al

't A '

. . i M 6 D O <

a: <

TABLE 2.2-l' (Continued)

REAC10R TRIP SYSTEM INSTRUMENTATION TRIP SETPOINIS NOTA 1 ION N0ll 1: (continued)

K y

- 1.069 Ky = 0.00940 K - 0.000494 .

3 z:

1 i .is g

= lead-lag compensator on measured Tc g i e is 1

g m

2 m

= me c nstants utilized in the lead-lag controller for T c, i g = 10 secs., g i

g,v2 -c i '3 s#Cs" 2 N

_i ~

e K

S = Laplace transform operator sec W

and fj(Aq) is a function of the indicated difference between the sum of the upper detector pair and the sum of the lower detector pair of the power range nuclear ton chambers;'with gains to be selected based ori measured instrument response during platit startup tests such that:

(i) for gt - gh between -35 percent and *10.0 percent f)(Aq) = 0 (where qt equals the sum of the upper detector pair and qb equals the sum of tiie lower detector ,

pair in percent RAILD lilERMAL POWER, and qt

• gb equals the total TilERMAL POWLR tri percent of RAIED lilERMAL POWER).

(ii) for each percent that the magnitude of (qt - gb) exceeds -35 percent, the N-16 trip setpoint shall be automatically reduced by 1.25 percent of its value at RAlED lilERMAL POWER.

COMANt:lli Pi AK llNil 1 A-7 4 5W): 10/0$01114

e TABLE 2.2-l' (Continued)

REACIOR 1 RIP SYSIEM. INSTRUMENTATION TRIP SETPOINTS-NOTA 110N N0ll 1: (continued)

(ill)

- for each percent that the magnitude of (qt - qb) exceeds +10 percent, the N-16 ,

trip setpoint shall be automatically reduced by 1.55 percent of its value at RAltl)

TitCRMAL POWER.

g Ihe channel's maximum trip setpoint shall not exceed its computed trip point by more.than 1.4 Null 2:

percent N-16 span (150 percent RIP).

~

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5' 8

m E

o E

M s

(n w

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~'i.: y WE:STINGHOUSE PROPRIETARY CLASS 3 2.2 = LIMITING SAFETY SYSitM dttitaus SASES ,

2.2.1 RESCTOR TRIP SYSTEM INSTRUMENTATICN SETPOINTS

'The Reactor Trip"Setpoint Limits specified in Table 2.2-1 are the

~

nominal values at which the Reactor Trips are set.for each functional unit. The Trip Setpoints have been selected to ensure that the reactor core and reactor coolant system are prevented f rom exceeding their

~

safety limits during normal operation and design basis anticipated operational occurrences and to assist the Engineered Safety Features Actuation System in mitigating the consequences of accidents. The setpoint for a reactor trip system or interlock function is considered to be adjusted consistent with the nominal value when the "as measured" setpoint is within -the band allowed for calibration accuracy.

To accommodate.the instrument drift assumed to occur between operational tests and the accuracy to which setpoints can b'e measured and calibrated, Allowable Values for the reactor trip setpoints have been specified in Table 2.2-1. Operation with setpoints less conservative than the Trip Setpoint'but within the Allowable Value is acceptable since an allowance has been made in the safety analysis to accommodate

.this error. An optional provision has been included for determining the OPERABILITY of a channel when its trip setpoint is found to exceed the Allowable Value. The methodology of this option utilizes the "as measured" deviation from the specified calibration point for rack and sensor components-in conjunction with a statistical combination of the other uncertainties in calibrating the instrumentation. In Equation 2.2-1, Z + R + S 1 TA, the interactive ef fects of the errors in the rack and the sensor, and the "as measured" values of the errors are considered. Z, as specified in Table 2.2-1, in percent span, is the statistical summation of errors assumed in the analysis excluding those associated with the sensor and rack drift and the accuracy of their A-9 45550: 10/013134 .

. WESTINGHOUSE PROPRIETARY CLASS 3 messarement. TA or Total Allowance-is the dif f erence, in percent span, tet,,een the trip setcoint and the value used in the analysis for reactor trip. R or Rack -Error is the *)s measured" deviation, in percent span, for the affected channel from the specified trip setpoint. 5 or Sensor

~

Error _is either the as measured" deviation of the sensor from its calibration point or the value specified in Table 2.2-1, in percent [

- span, from the analysis assumptions. Use of Equation 2.2-1 allows for a sensor drift factor, an increased rack drift factor, and provides a l tnreshold value for REPORTABLE OCCURRENCES.

~

The methodology to derive the trip setpoints is based upon combining all of the' uncertainties in the channels. Inherent to the determination of the trip setpoints are the magnitudes of these channel uncertainties.

1 Sensors and other instrumentation utilized in these channels are expected to be capable of operating within the allowances of these l uncertainty magnitudes. Rack drift in excess of the Allowable Value exhibits the behavior that the rack has not met its allowance. Seing that there is a small statistical chance t,at h this'will happen, an

-infrequent excessive drift is expected. Rack or sensor drif t, in excess  ;

of the allowance that_is more than occasional, may be indicative of more  ;

i serious problems and'should warrant further investigation.

t F . ,

a L

i i

F A-10 45550: 10/013184

9

• .*' WESTIfGOUSE PROPRIETARY CLASS 3 3/4.3.2 INGINEE9E0 SAFETY FEATURE ACTUATION SYSTEM INSTRUMENTATION LIMITING CON 0! TION FOR OPERATICN 3.3.2 The Engineered Safety Feature Actuation System (ESFAS) instrumentation channels and interlocks shown in Table 3.3-3 shall be OPERABLE with their trip setpoints set consistent with the values ,shown '

in tne Trip Setpoint column of Table 3.3-4 and with RESPONSE TIMES as snown.in Table 3.3-5.

ApPLICA8(L[TY: As'shown in Table 3.3-3.

ACTION:

a. With an ESFAS instrumentation or interlock setpoint trip less '

conservative than the value shown in the Trip Setpoint column of Table 3.3-4 adjust the setpoint consistent with the Trip Setpoint value. .

b. With an E'SFAS instrumentation or interlock setpoint less conservative than the value shown in the Allowable Values column of

• Table 3.3-4, place the channel in the tripped condition within 1 hour1.157407e-5 days <br />2.777778e-4 hours <br />1.653439e-6 weeks <br />3.805e-7 months <br />, and within the following 12 hours1.388889e-4 days <br />0.00333 hours <br />1.984127e-5 weeks <br />4.566e-6 months <br /> either:

l. Determine that Equation 2.2-1 was satisfied f or the af f ected enannel and adjust the setpoint consistent with the Trip

• Setpoint value of Table 3.3-4, or

2. Declare the channel inoperable and apply the appilcable ACTION statement requirements of Table 3.3.3 until the channel is restored to OPERABLE status with its setpoint adjusted consistent with the Trip Setpoint value.

EQUATION 2.2-1 Z

• R

• S 5 TA A-Il 4555Q: 10/013184

~ ^

• w ~- - - = - -

<:(

~ . _. . - ___

{'

. .. t 4f . y-s' ~

WESTINGHOUSE PROPRIETARY CLASS 3

' m{ f(v-

w. o q; ' ) .('

( ,

i

, _. dg

-yt - .nere: _

v \

l 3 -4 for the affected cdannel,

-f:

• Z =

.tlh'e' d' value f or column I of Tab e 3.

1

~

R = the'"as measured" value (in percent span) of rack error for the j affected-channel, 5 = either the *as measured" value (in percent span) of the sensor  ;

i 3

error, or the value in column S of Table 3.3-4 for the affected -

s.

c channel, and i: ,

j- s

.TA = the value frem column TA of Table 3.3-4 for the affected channel.

( ,

()3 (

Ii r

,t .

< N , ..

. I Lg y ,

y f;

.M t .- l 3 -r (

\} U . - -

t l

hh 9r iI[< t i

1, ,' , s , (;l.

,4j if.3;i -

ib q ,

i (

ll r i

, (I  :

rr  ?

p? ;i '

'L t,'

.4 y  :

, i n'

s

' 4[ '

- 45550:10/013184 A-12 }

. q 3

TABLE 3.3-4 ENGINEERED SAFE 1Y FEATURE AClUA110N SYSTEM IRIP SEIP0lNIS Total Sensor Trio Setpoint Allowable Value functional tinit Allovance {TA) Z Drift (S)

1. SAftlY IN]IC110N, TURBINE TRIP AND fil0WAILR ISOLATION NA g.

NA NA -NA NA A. Manual Initiation NA NA Q 11 . Automat ic Actuation Logic NA NA 0.71 NA 1.5 1 3.35 psig 5 3.9 psiu d C. Containtuent Pressure - High 2.5 h 1823 psig 19 16.1 14.41 1.5 1 1829 psig D. Pressurlier Pressure - Low 17.3 14.81 1.5 1 605 psig 1 586 psig (Note a) ,

g 1.'. Steamline Pressure - Low $

2. CONIAINitt.NI SPRAY @

NA NA @

A. Manual Initlation NA NA NA NA NA NA $.

M B. Automatic Actuation Logic NA NA 0.71 $ 18.35 psig $ 18.9 psig C. Containment Pressure - 2.5 1. 5 -

h l

i liigh liigli-liigh ,

fl B;

3. CONI AlHillNI ISulA110N u, L^8 A. Phase "A" Isolation NA NA NA NA -NA j 1. Manual Initlatlon NA NA NA (4A NA i 2. Automatic Actuation I og i t'

3. Safety injection See item I above for all Safety injection Trip Setpoints/ Allowable Values i

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~. 2-w - - , , , ,,e - , , - r-- - - - - e-w. -. ,- a , -- - --w

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. .. .i TABLE 3.3-4 (Continued) ,

ENGINEERED SAFELY FEATURE ACTUATION SYSltH TRIP SEIPOINlS Total Sensor functional tinit Allowance (TAl 7 Drift (S) Trip Setpoint Allowable Value

!!. Phase "11" Isolation

1. Manual Initiation NA NA NA NA NA

2. Automatic Actuation NA NA NA NA NA

3. Containment Pressure - 2.5 0.71 1.5 5 18.35 psig i 18.9 psig h liigh-liigh-liigh y E5 n'

C. Ventilation Isolation I. Manual Initlation NA , NA NA NA NA -

h rn

2. Automatic Actuation NA NA NA NA NA o

l og ic See item I above for all Safety Injection Trip Setpoints/ Allowable Values o

3. '.afety injection N

4. S!LAN tINL ISOLA 110N g B

NA K A. Manual Initiation NA NA NA NA ll. Automatic Actuation Logic NA NA. NA NA NA p C. Containment Pressure - 2.5 0.71 1.5 1 6.35 psig 5 6.9 psig g u) liigh liigh 2 586 psig (Note a) W O. Ste.ualine Pressure - Low 17.3 14.81 1.5 1 605 psig L Negative Steam Pressure Ita t e -liigh 11 . 0 0.5 0.0 1 100 psi i 111.6 psi (Note b)

COMANClit I'lAK llNlI I 4 5$51); 111/0$01114 A-14

d TABLE 3.3-4 (Continued)

ENGINEERED SAFE 1Y FEATURE ACTUATION SYSTEM 1 RIP SElPOINIS Total Sensor f unc t ional tinit Allowance-(TAL 7 Drift (S) Trip Setpoint Allowable Value i 5. IllitillNL IRIP AND FEEDWATER IS0tAllON

a. Automatic Actuation Logic NA NA NA NA NA 8:

b. a. Steam Generator Water 1.6- 4.3 1.5 5 82.4% of narrow range s 84.2% of narrow r.

level - liigh-liigh tinit 1. instrument span ..

instrument span h 1: b. ' Steam' Generator Water 4.2 2.18 1.5 5 76.8% of narrow rsnge 5 78.4% of narrow r t evel - liigh-liigh' Unit 2 instrument span instrument span h

- E3 o

6. AtlXil I AltY F EEDWAIER m u

NA NA g A. Manual Initiation NA NA NA NA gg

11. Automa t ic Actuation logic NA NA NA NA Steam Generator Water 8.8 7.08 1.5 1 43.4% of narrow range 1 42.1% of narrow r y C a.

instrument span H instrument span level - tow-low Unit 1 h C. h. Steam Generator Water 19.4 17.38 1.5 2 19.4% of narrow range 2 17.8% of narrow r ,

instrument span instrument span ,

tevtl - Low-l.ow Unit 2 D. Salety injection See item 1 above for all Safety injection Trip Setpoints/Allowble values i St a t ion tilact.out NA NA NA t 4830 kV 2 4781 kV v3 NA NA NA u, I trip of Ma)" feedwater flA NA Pumps J. Automatic Switchover to Containment Sump NA NA A. Aut onat ic Actuation Logic NA NA NA Anil Attualion Relays 11 . Hu?. I level - low Coincident 2.6 0.71 1.5 > 18'-10" from tank base > 18'-5.S" from tank base with Safety injection (a) lime constants utilized in the lead-lad' controller for steam pressure low are ij t 50 seconds and i,5 5 setonds.

(b) the. time constant utilized in the rate-lag controller for steam pressure rate - high = 50 seconds.

COMANCH' l'l AK - !! Nil 1 A-15 4SSSO "Psultl4. , _ .

e 9

TABLE 3.3-4 (Continued)

ENGINEERED SAFETY FEATURE' ACTUATION SYSTEM TRIP SETPOIN1S .

Total Sensor Allowance (TA) 7 Drift (S)_ Trio Setpoint Allowable Value f unc t ional linit H. Loss of Power (6.9 kV Safe-guards) System Undervoltage

a. Preferred Offsite :c Source Undervoltage: > 4781 V Di undervoltage Relays NA NA NA 4830 V 2 0.825 sec. El NA NA 0.75 sec.

Diesel Start Timer NA NA NA NA 0.5 sec. 50.55sec. y Source Bkr. Irlp Timer -

S v>

m .

b. Bus lindervoltage m

• no

1) Diesel Start -

NA NA 4830 V > 4781 V @

Undervoltage Relays NA R NA NA 0.75 sec. 5 0.825.sec.

limer NA 0 M

.. 2) Initiation of Solid State Safeguards System P Sequences NA 4030 V i 4781 V @

O' lindervoltage Relays NA NA MA NA NA sec. 1 0.55 sec. w limers

9. Safety Chilled Water System Attuation NA NA NA NA NA

a. Automation Actuation iogit and Actuation Relays Safety injection See item 1 above for all Safety injection Trip Setpoints/Allowble Values b.

NA NA NA NA NA

c. tilatkout Sequence COMANCitt itAK - IINil 1 IK--Eh

o

' ~

~

. TABLE 3.3-4 (Continued) .,

ENGINEERED SAFETY FEATURE ACTUATION SYSTEM TRIP SE190lN15 Total Sensor Allowance (lA) Drift (S) Trip Setpoint Allowable Value functional IJnit Z

). Control Room isolation NA NA NA NA

a. Manual Inillation NA aC NA NA NA NA

b. Automatic Actuation NA h

Logic and Actuation c Relays 25 Blackout Sequence NA NA. NA NA NA h c.

NA NA Smoke Density NA NA NA

d. o-u

). [ngineered Salety features  %

Actuation System Interlocks -

a Pressurizer Pressure, NA NA NA nominal 1960 psig i 1974 psig h a.

N01 -P -ll NA nominal 1960 psig > 1946 psig

b. Pressuriier Pressure, NA NA.

w P ll NA nominal 553*f > 550.l*f NA NA

c. l avg l ow-Low P-12 NA NA HeatIor trip, P-4 NA NA NA d.

4 t0MANClli PlAK tlN il I p)y

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n

• j ,* ' WESTINGHOUSE PROPRIETARY CLASS 3.

3/4.3 INSTRUMENTATION BASES 3 / 4 . 3 .' 1 and 3/4.~3.2 REACTOR TRIP AND ENGINEEREO SAFETY FEATURE ACTUATION SYSTEM INSTRUMENTATION ine'0PERABILITY of the Reactor Protection System and Engineered Safety

-Feature Actuation System Instrumentation and interlocks ensure that 1)

~

the associated action and/or reactor trip will be inititted when the parameter monitored by each channel or combination thereof reaches its setpoint, 2) the specified coincidence logic is maintained, 3) sufficient redundancy is maintained to permit a channel to be out of service.for testing or maintenance, and 4) sufficient system functional capability is available from diverse parameters.

The OPERABILITY of these systems is required to provide the overall reliability, redundancy, and diversity ass.umed.available in the facility _

design for the protection and mitigation of accident and transient conditions The integrated. operation of each of these systems is consistent with the assumptions used in the_ accident analyses. The

~

surveillance requirements'spectfied for these systems ensure that the l ,

overall system ~ functional capability is maintained comparable to the.

3 original' design standards. The periodic surveillance tests performed at

,the. minimum frequencies are sufficient to demonstrate this capability; I

• The Engineered Safety Feature. Actuation System Instrumentation Trip "Setpoints specified in Table 3.3-4 are the nominal values at which the

~

A setpoint is considered to bistables'areLset for each functional unit.

tbe adjusted' consistent with the nominal '/aiue when the "as measured" setpoint is within the band. allowed for calibration accuracy.

To' accommodate the instrument drift assumed to occur between operational

. tests and'the accuracy to which setpoints can ce measured and

~

A-1B I 45550:10/013184

- , 'dESTINGHOUSE PROPRIETARY CLASS 3 cal'oratec. D'cwable Values for ne setpoints have been specified in Tacle 3.3-4 Operation'witn setpoints less conservative than the Trio

, Setpoint but witnin the Allowab.'le Value is acceptable since an allowance has been made in the safety analysis to accommodate this error. An optional provision has been included for determining the OPERASILITY of a channel wnen-its trip setpo'.,nt is found to exceed the Allowable Value. The methodology of this option utilizes the *as measured"

'eviation from the spPcified calibration point for rack and sensor d

components in conjunct-lon with a statistical combination of the o-ther uncertainties of the instrumentation to measure the process variable and the uncertainties in calibrating the instrumer.'.ation. In Equation 2.2-1, Z + R + S 1 TA, the interactive ef f ec*.s of the errors in the rack and th.! sensor, and the "as measured" values of the errors are considered. Z, as specified in Table 3.3-4, in percent span, is the statistical summation of errors assumed in the analysis excluding those associated with the sensor and rack drif t and the accuracy of their measurement. TA or Total Allowance is the difference, in percent span, between the trip setpoint and the value used in the analysis for the

' actuation. R or Rack Error is the' "as measured" deviation, in percent span, for the af f ected channel f rom the specified trip setpoint. S or Sensor Errar is either the "as measured" deviation of the sensor from its calibration point or the value specified in Table 3.3-4, in percent span, from the analysis assumptions. Use of Equation 2.2-1 allows for a sensor drif t f actor, an increased rack drif t f actor , and provides a threshold value for REPORTABLE OCCURRENCES.

• The methodology to derive the trip setpoints is based upon combining all of the uncertainties in the channels. Inherent to the determination of the trip setpoints are the magnitudes of these channel uncertainties.

Sensor and rack instrumentation utilized in'tnese channels are expected to be capable of operating within the allowances of these uncertainty magnitudes. Rack drift in excess of the Allowable Value exhibits the behavior that the rack has not met its allowance. Seing that there is a small statistical chance that this will happen. an infrequent excessive 4S550: 10/013184 A-19

o ,

• ~> - WESTIf;GHCUSE PRCPRIETARY CLASS 3 Orif: is ex;ec et. Rac'< ar sensor dri f t, in excess of the al'awance

na is :cre tnan oc:asional, may be indicative of more serious problems and should warrant furtner investigation.

t l

I A-20 45550:10/013184