ML20063K011

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Proposed Tech Specs Decreasing Maximum Allowable Value for OTN-16 & Increasing Minimum Allowable Value for Pressurizer pressure-low for Unit 2
ML20063K011
Person / Time
Site: Comanche Peak  Luminant icon.png
Issue date: 02/14/1994
From:
TEXAS UTILITIES ELECTRIC CO. (TU ELECTRIC)
To:
Shared Package
ML20063J995 List:
References
RTR-NUREG-1468 TXX-94046, NUDOCS 9402280041
Download: ML20063K011 (16)
v • d • e


Text

-_ _ - - _ _ _ _ _ _ _ - - _ _ _ _ _ _ _ - _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ - - _ _ _ _ _ _ _ _ _ - _ _ . _ - _ - .

Attachment 3 to TXX-94046 Affected Technical Specification Pages (NUREG-1468) l Pages 2-4 to 2-8, 2-11, B2 3 3/4 3-13, 3/4 3-25 to 3/4 3-30 B3/4 3-1, and B3/4 3-2 I

i l

I 9402280041 940214 PDR P ADOCK 05000445 PDR

SAFETY LIMITS AND LIMITING SAFETY SYSTEM SETTINGS 2.2 LIMITING SAFETY SYSTEM SETTINGS REACTOR TRIP SYSTEM INSTRUMENTATION SETPOINTS 2.2.1 The Reactor Trip System Instrumentation and Interlock Setpoints shall be set 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 but more conservative than the value shown in the Allowable Value column of Table 2.2-1, adjust the setpoint consistent with the Trip Setpoint value.
b. With the Reactor Trip System Instrumentation or Interlock Setpoint less conservative than the value shown in the Allowable Values column of Table 2.2-1,fiilth Adjust the setpoint consistent with the Trip Setpoint value of l Table 2.2-1 and determine within 12 hours1.388889e-4 days <br />0.00333 hours <br />1.984127e-5 weeks <br />4.566e-6 months <br /> that Equation 2.2-1 l was satisfied for the affected channel, or j 2.

()[WstatementrequirementofSpecification3.3.1untilthechannelp$clar is restored to OPERABLE status with its setpoint adjusted cor.sistent with the Trip Setpoint value.

Equation 2.2-1 Z + R + 5 s TA ty Where:

2 - The value from 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 from Column S (Sensor Error) of Table 2.2-1  ;

for the affected channel, and j TA - The value from Column TA (Total Allowance) of Table 2.2-1 for  :

the affected channel.

I COMANCHE PEAK - UNITS 1 AND 2 2-4 1

TABLE 2.2-1 8

g REACTOR TRIP SYSTEM INSTRUMENTATION TRIP SETPOINTS L SENSOR) i y ALLOWANCE ERROR 9

n FUNCTIONAL UNIT fTA) Z fS) TRIP SETPOINT ALLOWABLE VALUE

l. Nanual Reactor Trip N.A. N.A. N.A. N.A. N.A E k g 2. Power Range, Neutron Flux

~

a. High Setpoint i 7.5 4.56 1.25 s109% of RTP* s111.7% of RTP*

SE

b. Low Setpoint 4.56 1.25 s25% of RTP* $27.7 of RTP*

[ { 8.3

3. Power Range, Neutron Flux, I .6 0.5 0 1 $5% of RTP* with s6.3% of RTP* with High Positive Rate k a time constant a time constant

} [ 22 seconds 22 seconds i I

'? 4. Power Range, Neutron Flux, 1.6 0.5 0 s5% of RTP* with 56.3 of RTP* with High Negative Rate l a time constant a time constant 22 seconds 22 seconds i

ec 5. Intermediate Range, 17.0 8.41 0 i s25% of RTP* s31.5 of RTP*

Q Neutron Flux

6. Source Range, Neutron Flux !17.0 10.01 0 I s105 cps $1.4 x 105 cps

[ *-*  ;

\

FF 7. Over_ temp rature N-16  ! 4 y

g"

a. Unit 1 -

l 10.53 6.70 0.76',.10+ M 1.0+1 3 - 3 D

. Unit 2 10.0 6.75 .

g. See Not

.. w y,38+,,heNote1 0, 0 gm E

53

  • R ^ ---

"m M (TP - RAIED

1) 1.0% span forTl!EMBL_P_0WER N-16 power monitor, 1.10% for T RTDs and 0.76% for pressurizer pressure sensors.

(2) 1.0% span for N-16 power monitor,1.38% for T,c,to RTDs and 0.96% for pressurizer pressure sensors. l' otd

( - --~~_ __#

___ _ _ ~ ~ '____ __._.

g TABLE 2.2-1 (Continued) x E

o REACTOR TRIP SYSTEM INSTRUMENTATION TRIP SETPOINTS A / ALLOWANCE ERROR \

N FUNCTIONAL UNIT (TA) (S)

Z

\TRIPSETPOINT ALLOWABLE VALUE h 8. Overpower N-16 4.0 2.05 1.0+0.05'" sll2% of RTP* sil4.5% 'of RTP* l

~

-< \

9. Pressurizer Pressure-Low

~

2-

~ a. Unit 1 4.4 0.71 2.0 .

21880 psig ,?l863,6_psig g b. Unit 2 4.4 1.12 2.0 j 21880 psig ' 41863.6 psig l m 10. Pressurizer Pressure-High f f $I ' '

a. Unit 1 i 7.5 5.01 1.0 $2385 psig $2400.8 psig
b. Unit 2 k 7.5 1.12 2.0 s2385 psig $2401.4 psig
11. Pressurizer Water Level-High ! l ,

AN Q / 8.0 2.18 2.0 /'s92% of instrument 593.9% of instrumenh

O pan span #
b. Unit p ; / 8.0 2.35 2.0 [s9Ifof inshument-~s93.91RiFinstrument A Qspan span CC 11 12. Re c tor Coolant Flow-Low 1 4

"~ a.'Jnit 1 2.5 1.18 0.6 290% of loop 288.6% of loop

design flow ** design flow **

h. Unit 2 2.5 1.25 0.87 290% of loop 188.8% of loop

{E

=E .

minimum measured fl ow**

  • minimum measured fl ow* **

-j g - - -

m

,,Q3)1.0%spanforN-16_powermonitorand0.05%for_T ~~

m -~~RTDs jin 7TPTRATED THCRMAL POWER

    • Loop design flow - 99,050 gpm l

] "

      • Loop minimum measured flow - 98,500 gpm

~

E g IABLE 2.2-1 (Continued) .-

M g REACTOR TRIP SYSTEM INSTRUMENTATION TRIP SETPOINTS aL f I. TOTAL SENSOR x ALLOWANCE FUNCTIONAL UNIT (IA) Z ERROR (S) ( TRIP SLTPOINT c  ; ALLOWABLE VALUE 1

$ 13. Steam Generator Water )

in Level - Low-Low ,

~

a. Unit 1 -

25.0 22.08 2.0 225.0% of narrow g 223.1% of narrow a

range instrument- range instrument span span N b. Unit 2 35.4 22.2 2.0 235.4% of narrow 233.4% of narrow range instrument range instrument span span

14. Undervoltage - Reactor ,

Coolant Pumps j g

I a. UNIT I 7.7 1.2 0 24830 volts- 24753 volts-m l

{ arJLbus. - each bus Unit 2' 7.7 1.2 0 ,

(eachbus24830 24753 each vo1vo1V%

bus y R j

15. Underfrequency - Reactor i ec Coolant Pumps  !

hh C Unit 1 % ,

4.4 0 0 f (i57.2 Hz 257.06 Hz' ,

l m- b. Unit 2j 4.4 0 0 (257.2Hz 257.0 ,6 HC

16. Turbine Trip kk oa
a. . Low Trip System Pressure N.A. N.A. N.A. 259 psig 246.6 psig
b. Turbine Stop Valve  ;

@@ N.A. -H.A. N.A. 21% open' 21% open g@ Closure g or  ;

17. Safety injection Input- I N.A. N.A. N . A .- ) N.A. N.A.

from ESF j L

y T ABLE 2.2-1 (Cont inue<!) .

y Rf ALIGILIRIP SYSJiH INSTRUM[NTA110N IRIP SfiPOINTS m , -

3 .,

o j 101Al SENSOR 9 All 0WANCE ERROR }

{ FUNCTIONAL UNIT liA) L (S) / 1 RIP SEIPOINT All0WABLE VAlUE E 18. Reactor Trip System

] Interlocks f

a. Intermediate Range 'N.A. N.A. H.A. I x 10
  • amps 26 x 10'" amps E Neutron Flux, P-6 f
b. Low Power Reactor Trips Block, P-7
1) P-10 input N.A. N.A. H.A. 10% of RTP* s12.7% of RTP*
2) P-13 input N.A. N.A. h.A. 10% RTP* Turbine $12.7% RTP* Turbine First Stage Pres- First Stage Pressure

,? 4 sure Equivalent Equivalent

c. Power Range Neutron N.A. N.A. N.A. 48% of RTP* s50.7% of RTP*

Flux, P-8

d. Power Range Neutron N.A. N.A. N.A. s50% of RTP* $52.7% of RTP*

Flux, P-9 e.

Power Range Neutron .

N.A. N.A. N.A. 10% of RTP* 27.3% of RTP*

Flux, P-10 }

19. Reactor Trip Breakers N.A. N.A. N.A. N.A. N.A.
20. Automatic Trip and Interlock N.A. N.A. N.A. N.A.

Logic N.A.)

  • RTP = RATED TilERMAL POWER

I i

n TABLE 2.2-1 (Continued) g TABLE NOTATIONS (Continued) 2 -

y NOTE 1: (Continued) y For Unit 2 n

i (1) for q - qs between -52% and +5.5%, f (aq) - 0, where q c-RATED, THERMAL POWER in the top and bo,ttom halves of respectively.

core the, and q, are percer.t and q, + q, is total THERMAL POWER in percent of RATED THERMAL POWER, w

(11) for each percent that the magnitude of q - q, exceeds -52%, the N-16 Trip g Setpoint shall be automatically reduced by 2.15% of its value at RATED THERMAL '

o POWER, and m

(iii) for each percent that the magnitude of q -q exceeds +5.5%, the N-16 Trip Setpoint shall be automatically reduced by 2.37% of its value at RATED THERMAL POWER.

m NOTE 2: The channel's maximum Tr_lp Setpoint shall not exceed its computed Trip Setpoint by more than 3.51%

l l h of span for Unit I or,688tgof span for Unit 2.

05

??

~~

8 8

%a

~

~=

b

Ml 2.2 LIMITING SAFETY SYSTEM SETTINGS BASES l

2.2.1 Rf. ACTOR TRIP SYSTEM INSTRUMENTATION SETPOINIS  !

i 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 l Setpoints have been selected to ensure that the core and Reactor Coolant System are prevented from 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 duisapirsd" setpoint l is within the band allowed for calibration accuracy and instrument dtift.

YD To accommodate the instrument drift assumed to occur between operational tests and the accuracy to which setpoints can be measured and calibrated.

Allowable Values for the Reactor Trip Satpoints 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 errorJAn optionar provision has been 7 P'Tncluded for ostermining the OPLRABILITY 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 of the instrumentation to measure the process variable and the uncertainties in calibrating the instrumentation. In Equation 2.2-1, Z + R + 5 s TA, the interactive effects 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 l errors assumed in the analysis excluding those associated with the sensor and rack drift and the accuracy of their measurement. TA or Total Allowance is the difference, in percent span, between the Trip Satpoint and the value used in the analysis for Reactor trip. R or Rack Error is the *as measured" deviation,  !

I in percent span, for the affected channel from the specified Trip Setpoint. S 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 threshold value for U

( REPORTABLE EYDfTS.

The monodology to derive the Trip Setpoints is based upon combining all of ,

J the uncertataties in the channels. Inherent to the determination of the Trip Setpoints are the magnitudes of these channel uncertainties. Sensors and other instrumentation utilized in these 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. Being that there is a small statistical chance that this will happen, an infrequent excessive drift is expected. Rack or sensor drift, in excess of the allowance that is more than occasional, may be indicative of more serious problems and should warrant further investigation.

COMANCHE PEAK - UNITS 1 AND 2 B 2-3

l INSTRUMENTATION 3/4.3.2 ENGINEERED SAFETY FEATURES ACTUATION SYSTEM INSTRUMENTATION

~

LIMITING CONDITION FOR OPERATION 3.3.2 The Engineered Safety Features Actuation System (ESFAS) instrumentation channels and interlocks shown in Table 3.3-2 shall be OPERABLE with their Trip Setpoints set consistent with the values shown in the Trip Setpoint column of r Table 3.3-3.

APPLICABILITY: As shown in Table 3.3-2.

ACTION:

a. With an ESFAS Instrumentation or Interlock Trip Setpoint trip less conservative than the value shown in the Trip Setpoint column but more conservative than the value shown in the Allowable Value column of Table 3.3-3, adjust the Setpoint consistent with the Trip Setpoint value.
b. With an ESFAS Instrumentation or Interlock Trip Setpoint less Table 3.3-3,fliither: conservative than the(value shown in l
1. Adjust the Setpoint consistent with the Trip Setpoint value of j
t. Table 3.3-3, and determine within 12 hours1.388889e-4 days <br />0.00333 hours <br />1.984127e-5 weeks <br />4.566e-6 months <br /> that Equation 2.2-1) f was satisfied for the affected channel, or _ _

j ,

2.i gedlare the channel inoperable and apply the applicable ACTION k fatement requirements of Table 3.3-2 until the channel is i restored to OPERABLE status with its Setpoint adjusted consistent with the Trip Setpoint value.

[ Equation 2.2-1 Z + R + S 5; TA p Where:

y Z - The value from Column Z of Table 3.3-3 for the affected channel, I

i 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 i error, or the value from Column S (Sensor Error) of Table 3.3-3 for the affected channel, and TA - The value from Column TA (Total Allowance) of Table 3.3-3 for the affected channel,

c. With an ESFAS instrumentation channel or interlock inoperable, take the ACTION shown in Table 3.3-2.

COMANCHE PEAK - UNITS 1 AND 2 3/4 3-13

n y TABLE 3.3-3 z

k ENGINEERED SAFETY FEATURES ACTUATION SYSTEN INSTRUMENTATION TRIP SETPOINTS h ,

< SENSOR

^ / TOTAL ERROR

' FUNCTIONAL UNIT  ! ALLOWANCE (TA) I (S) TRIP SETPOINT ALLOWABLE VALUE E SafetyInjection(ECCS,ReactorTrip,l p 1. ,

,f-m Feedwater Isolation, Control Room

~ Emergency Recirculation, Emergency /

g; Diesel Generator Operation, Contain- I o ment Vent Isolation, Station Service  !

N Water, Phase A Isolation, Auxiliary I I

Feedwater-Motor Driven Pump, Turbine Trip, Component Cooling Water, Essential Ventilation Systems, and .

t w Containment Spray Pump).

w a. Manual Initiation N.A. N.A. N.A. N.A. N.A

b. Automatic Actuation Logic N.A. N.A. N.A. N.A. N.A and Actuation Relays
c. Containment Pressure--High 1 2.7 0.71 1.7 53.2 psig $3.8 psig c

a

% d. Ere u zer Pressure--Low _

- 15.0 10.91 2.0 20 psig e

I it

2) Unit 2 15.0 11.3 2.0 21803.6 W [4

@(21820 psig21803.6 ps F

= e. Steam Line Pressure--Low

1) Unit 1 17.3 15.01 2.0 2605 psig* 2593.5 psig*

h 17.3 9.15 2.0 2605 psig* 2578.4 psig*

g 2) Unit 2 g 2. Containment Spray

- a. Manual Initiation N.A. N.A. N.A. N.A. N.A

b. Ac omatic Actuation Logic N.A. N.A. N.A.- N.A. N.A ar- Actuation Relays Containment Pressure--Nigh-3 0.71 $18.2 psig s18.8 psig c.

Q7 _

l.7

ci j TABLE 3.3-3 (Continued) z ENGINEERED SAFETY FEATURES ACTUATION SYSTEH INSTRUMENTATION TRIP SETPOINTS 3

h n /

%#TOTAL SENSOR ERROR

' FUNCTIONAL UNIT ALLyANCE (TA) Z (S) TRIP SETPOINT ALLOWABLE VALUE C

$, Containment Isolation v 3.

- a. Phase "A" Isolation E N.A. N.A. N.A. N.A. N.A o I) Manual Initiation

" N.A. N.A

2) Automatic Actuation Logic N.A. N.A. N . A, and Actuation Relays -
3) Safety Injection See Item 1. above for all Safety Injection Trip Setpoints and w Allowable Values.

'A w b. Phase "B" Isolation

1) Manual Initiation See Item 2.a above. Phase "B" isolation is manually initiated when containment spray function is manually initiated.
2) Automatic Actuation Logic ' N.A. N.A. N.A.$ N.A. N.A and Actuation Relays
3) Containment Pressure-- 2.7 0.71 1.7 s18.2 psig s18.8 psig High-3 j Containment Vent Isolation I) Hanual Initiation See Items 3.a.1 and 2.a above. Containment Vent Isolation is manually initiated when Phase "A" isolation function or containment spray function is manually initiated.
2) Automatic Actuation Logic.

N.A. H.A. N.A and Actuation Relays N. h

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

L

~- , s e - .,v. ee

. ~

n -

l TABLE 3.3-3 (Continued) z 3 ENGINEERED SAFETY FEATURES ACTUATION SYSTEM INSTRUMENTATION TRIP SETPOINTS 3^

Q TOTAL- ERROR

' FUNCTIONAL UNIT ALLOWANCE (TA) Z (S) TRIP SETPOINT ALLOWABLE VALUE C

$4. Steam Line Isolation

a. Manual Initiation N.A. N.A. N.A. N.A. N.A
b. Automatic Actuation Logic N.A. H.A. N.A. N.A. N.A N and Actuation Relays
c. Containment Pressure--High-2 2.7 0.71 1.7 $6.2 psig $6.8 psig w d. Steam Line Pressure--Low 1 1) Unit 1 17.3 15.01 2.0 2605 psig* 2593.5 psig*
2) Unit 2 17.3 9.15 2.0 2605 psig* 2578.4 psig*
e. Steam Line Pressure -

Negative Rate--High (7100pst**

t l'jDnit1

/

V 8.0 0.5 0 .

sl78.7 osi+* 4>

2) Unit 2 8.0 0.25 0 (s100 psi **~ sl78.7 p

=

0 i

a n

' ~

l TABLE 3.3-3 (Continued) z k ENGINEERED SAFETY FEATURES ACTUATION SYSTEN INSTRUMENTATION TRIP'SETPOINTS h

^ TOTAL SENSOR)

ERROR '

' FUNCTIONAL UNIT ALLOWANCE (TA) 1 (S) TRIP SETPOINT ALLOWABLE VALUE.

C"

$5. Turbine Trip and Feedwater

<a Isolation g -a. Automatic Actuation Logic N.A. N.A. N. A. t N.A.

N.A o and Actuation Relays m

b. Steam Generator Water Level--High-High
1) Unit 1 kl 7.6 4.78 2.0 $82.4% of s84.3% of narrow narrow range -range instrument i instrument span

~

w span. -

h 2) Unit 2 -18.5 12.4 2.0 s81.5% of <83.5% of narrow

" narrow range range instrument p "

/ instrument span span.

~

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

1 2

a

.n O.

g I

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

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

, TABLE 3.3-3 (Continued) y ENGINEERED SAFETY FEATURES ACTUATION SYSTEM INSTRUMENTATION TRIP SETPOINTS z n 2

TOTAL SENSOR}

ERROR -

yFUNCTIONALUNIT ALLOWANCE (TA) 1 (S) TRIP SETPOINT ALLOWABLE VALUE n

e 6. Auxiliary Feedwater f E a. Automatic Actuation Logic . N.A. N.A. N.A. N.A. N.A and Actuation Relays

]

- b. Steam Generator Water g Level--Low-Low s 1) Unit 1 j 25.0 22.08 2.0 225.0% of 223.1% of narrow narrow range range instrument m

4 instrument span.

span.

2) Unit 2 35.4 22.2 2.0 235.4% of 233.4% of narrow

, narrow range range instrument

instrument span.

m span, i

U c. Safety Injection - Start See Item 1. above for all Safety Injection Trip Setpoints and Motor Driven Pumps Allowable Values.

d. Loss-of-Offsite Power .A. N.A. N.A. N.A. N.A
e. Trip of All Main Feedwater N.A. N.A. N.A. N.A. N.A g Pumps
  1. 7. Automatic Initiation of ECCS

- Switchover to Containment Sump

a. Automatic Actuation Logic N.A. N.A. N.A. N.A. N.A

{R b.

and Actuation Relays RWST Level--Low-Low M 1) Unit 1 2.5 0.71 1.25 240.0% of 238.9% of span a span

2) Unit 2 2.5 0.99 240.0% of 239.1% of span 2

1.25) span j

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

TABLE 3.3-3 (Contir,ued) n ,

ENGINEERED SAFETY FEATURES ACTUATION SYSTEN INSTRUMENTATION TRIP SETPOINTS m TOTAL d450R)

ERROR ALLOWANCE (TA) Z (S) t TRIP SETPOINT ALLOWABLE VALUE

%FUNCTIONALUNIT .

[8. Loss of Power (6.9 kV & 480 V Safeguards System Undervoltage) 5

[ a. 6.9 kV Preferred Offsite ) H.A. H.A. N.A. 25004 V $5900 V y Source Undervoltage 24900 V E b. 6.9 kV Alternate Offsite N.A. N.A. N.A. 25004 V 55900 V m Source Undervoltage 24900 V

c. 6.9 kV Bus Undervoltage N.A. N.A. N.A. 22037 V 21935 V 53450 V y d. 6.9 kV Degraded Voltage N.A. N.A. N. A. I 26064 V 25933 V 1 E. 480 V Degraded Voltage N.A. N.A. N.A. 2439 V 2435 V Y' f. 480 V Low Grid N.A. H.A. N.A. 2447 V 2443 V U Undervoltage
9. Control Room Emergency Recirculation
a. Nanual Initiation N.A. H.A. N.A.

J N.A. N.A E _ _ -

3 b. Safety Injection See Item 1. above for all Safety Injection Trip Setpoints and

- Allow.ble Values.

p 10. Engineered Safety Features g Actuation System Interlocks

a. p 5 a. Pressurizer Pressure, P-ll #

?+ 1) Unit 1 N.A. N.A. N.A. s1960 psig s1975.2 psig g 2) Unit 2 N.A. N.A. N.A. $1960 psig s1976.4 psig

- b. Reactor Trip, P-4 N.A. N.A. N. A. 4 N.A. N.A

11. Solid State Safeguards Sequencer N.A. N.A. N.A. N.A. N.A (SSSS) w _ _ - - - _ - _ _ - - . _ . - - -. . _ -

3/4.3 INSTRUMENTATIM BASES I .

3/4.3.1 and 3/4.3.2 REACTOR TRIP SYSTEM and ENGINEERED SAFETY FEATURES ACTUATION SYSTEM INSTRUMENTATION The OPERABILITY of the Reactor Trip Sye+am and the Engineered Safety Features Actuation System instrumentatior

  • interlocks ensures that: (1) the associated ACTION and/or Reactor trip wil. iltiated when the parameter
  • monitored by each channel or combination theicof reaches its Setpoint, (2) the specified coincidence logic and ::ufficient redundancy is maintained to permit
  • I a channel to be out-of-service for testing or maintenance consistent with main-taining an appropriate level of reliability of the reactor protection and engi-I neered safety features instrumentation, and (3) sufficiant system functional capability is available from diverse parameters.

The OPERABILITY of these systems is required to e the overall reli-ability, redundancy, and diversity assumed available in tne facility design for ,

the protection and mitigation of accident and transient conditions. The inte-grated operation of each of these systems is consistent with the assumptions used in the safety analyses. The Surveillance Requirements specified for these systems ensure that the overall system functional capability is maintained comparable to the original design standards. The periodic surveillance tests performed at the minimum frequencies are sufficient to demonstrate this capability. Specified surveillance intervals and surveillance and maintenn outage times have been determined in accordance with WCAP-10271, "Evaluatis ' Surveillance Frequencies and Out of Service Times for the Reactor Protection . _trumentation System", WCAP-10271 Supplement 2, " Evaluation of Surveillance Frequencies and Out of Service Times for the Engineered Safety Features Actuation System" and supplements to these reports as approved by the NRC and documented in the SER (letters to the Westinghouse Owners Group (WOG) dated February 21, 1985, February 22, 1989, and April 30, 1990). ,

The Engineered Safety Features Actuation System Instrumentation Trip Setpoints specified in Table 3.3-3 are the nominal values at which the bistables are set for each functional unit. A Setpoi tdsj;onsidgred to be adjusted ' / .

consistent with the nominal value when the "as : am cd"]Setpoint is within the V N band " lowed for calibration accuracy. W /e/r" /

lo accommodate the instrument drift assumed to occur between operational tests and the accuracy to wnich Setpoints can be measured and calibrated, Allow-l able Values for the Setpoints- have been specified in Table 3.3-3. Operation with Setpoints less conservative than the Trip Setpoint but within the Allowable Value i is acceptable since an allowance has been made in the safety analysis __to act -

modate this error. On optionaFprovision has been included for determining the

/~0MRABILITY 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 of the instrumentation to j measure the process variable and the uncertainties in calibrating the instrumen-

, tation. In Equation 2.2-1, Z + R + S s TA, the interactive effects of the errors  !

in the rack and the sensor, and the "as measured" values of the errors are con-sidered. Z, as specified in Table 3.3-3, in percent span, is the statistical i (summationoferrorsassumedintheanalysisexcludingthoseass sensor and rack drift and the accuracy of their measurement. TA or Total l Unit 1 - Amendment No. 13  !

COMANCHE PEAK - UNITS 1 AND 2 B 3/4 3-1 l

l

INSTRUMENTATION BASES I

REACTOR TRIP SYSTEM and ENGINEERED SAFETY FEATURES ACTUATION SYSTEM

, INSTRUMENTATION (Continued)

[Allowanceisthedifference,inpercentspan,RorRackErroristhe"as measured" deviation, in the percent span, for the affected channel from the g specified Trip Setpoint. S or Sensor Error is either the "as measured" deviation of the sensor from its calibration point or the value specified it p Table 3.3-3, in percent span, from the analysis assumptions. Use of Equation 2.2-1 allows for a sensor drift factor, an increased rack drift facto p ';

provides a threshold value for REPORTABLE EVENTS y The methodology to derive the Trip Setpoints is based upon combining all l 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 these 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. Being that there is a small statistical chance that this will happen, an infrequent excessive drift is expected. Rack or sensor drift, in excess of the allowance that is more than occasional, may be indicative of more serious problems and should warrant further investigation.

The measurement of response time specified in the Technical Requirements Manual at the specified frequencies provides assurance that the Reactor trip and the Engineered Safety Features actuation associated with each channel is completed within the time limit assumed in the safety analyses. No credit was taken in the analyses for those channels with response times indicated as not '

applicable. Response time may be demonstrated by any series of sequential, overlapping, or total channel test measurements provided that such tests demon-strate the total channel response time as defined. Sensor response time veri-fication may be demonstrated by either: (1) in place, onsite, or offsite test measurements, or (2) utilizing replacement sensors with certified response time.

The Engineered Safety Features Actuation System senses selected plant ['

parameters and determines whether or not predetermined limits are being exceeded. If they are, the signals are combined into logic matrices sensitive to combinations indicative of various accidents events, and transients. Once the required logic combination is completed, the system sents actuation signals g

to those Engineered Safety Features components whose aggregate function best '

serves the requirements of the condition. As an example, the following actions  !

may be initiated by the Engineered Safety Features Actuation System to mitigate the consequences of a steam line break or loss-of-coolant accident: (1) ECCS i pumps start and automatic valves position, (2) Reactor trip, (3) feedwater isolation, (4) startup of the emergency diesel generators, (5) containment spray pumps start and automatic valves position (6) containment isolation, (7) steam -

line isolation, (8) turbine trip, (9) auxiliary feedwater pumps start and automatic valves position, (10) station service water pumps start and automatic valves position, (11) Control Room Emergency Recirculation starts, and (12)  ;

essential ventilation systems (safety chilled water, electrical area fans, primary plant ventilation ESF exhaust fans, battery room exhaust fans, and UPS l ventilation) start.

Unit 1 - Amendment No. 13 l COMANCHE PEAK - UNITS 1 AND 2 B 3/4 3-2 l

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