ML20082M941
| ML20082M941 | |
| Person / Time | |
|---|---|
| Site: | Callaway  |
| Issue date: | 04/17/1995 |
| From: | UNION ELECTRIC CO. |
| To: | |
| Shared Package | |
| ML20082M938 | List: |
| References | |
| NUDOCS 9504240450 | |
| Download: ML20082M941 (17) | |
Text
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ULNRC-03198 -l l
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h ATTACIDENT FOUR l i
i PROPOSED TECHNICAL SPECIFICATION REVISIONS r
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9504240450 9504*.7 PDR ADOCK 050004B3
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TABLE'Y. 2-1 s REACTOR TRIP SYSTEM INSTRUMENTATION TRIP SETPOINTS ,
n
- TOTAL SENSOR ERROR '
{R FUNCTIONAL UNIT ALLOWANCE (TA) Z [S1 TRIP SETPOINT ALLOWABLE VALUE
- 1. Manual Reactor Trip N.A. N.A. N.A. N.A. N.A.
- 2. Power Range, Neutron Flux 5 a. High Setpoint 7.5 4.56 0 <109% of RTP* <112.3% of RTP*-
] b. Low Setpoint 8.3 4.56 0 125% of RTP* 128.3% of RTP*
- 3. Power Range, Neutron Flux, 2.4 0.5 0 High Positive Rate 14% of RTP* with 163% of RTP* with a time constant a time constant
>2 seconds >2 seconds
- 4. Deleted
- 5. Intermediate Range, 17.0 8.41 0 <25% of RTP* <35.3% of RTP*
p Neutron Flux
- 6. Source Range, Neutron Flux 17.0 10.01 0 1105 cps 1 1 6 x 105 cps
- 7. byertemperature aT 9.3 6.47 1.83 .See Note 1 See Note 2
+1.24***
- 8. Overpower AT 5. 7 fd 1.90 1.65 See Note 3 See Note 4
- 9. Pressurizer Pressure-Low 5.0 2.21 2.0 >1885 psig >1874 psig g 10. Pressurizer Pressure-High 7.5 4.96 1.0 < 2385 psig 12400 psig
@ 11. Pressurizer Water Level- 8.0 2.18 2. C' <92% of instrument <93.8% of instrument
,R High span span a
- 12. Reactor Coolant Flow-Low 2.5 1.38 0.6 >90% of loop >88.8% of loop
,5 minimum measured minimum measured flow ** fIow**
"w g *RTP = RATED THERMAL POWER 3 ** Minimum Measured Flow = 95.660 gpm
. ***Two Allowances (temperature and pressure, respectively)
__m_._-_.__ ___________________m _ .____.__m. -___.==_m_ _ _ _ _ e __ _ - 2___.=__m au____-_ __a 2 _ -._ _ _ As _s--
g TABLE 2Q_pntinuedl ,
n .
- p TABLE NOTATIONS , . ,
y -
3: -
U NOTE 1: OVERTEMPERATURE AT t
1 + tis) #
1 S)I f 1
- T' ] + K3 (P - P*) - f g(All)
@ s ATo{Kt-K2All(1++TSSI t4 )QT L1 + tgs; s
AT( (1 +SI t2(1 + T3Ss '
C
" Where: AT = Measured AT:
1 + tis = lead-lag compensator on measured AT:
, g t1, t2 = Time constants utilized in lead-lag compensator for AT, ti 2 8 s, t2 s 3 s; 1
= Lag compensator on measured AT:
9 g t3 - Time constant utilized in the lag compensator for AT, t3 = 0 s:
ATo - Indicated AT at RATED T11ERMAL POWER:
Kj = 1.15:
K2 = 0.0251/*F; .
+ = The function generated by the lead-lag compensator for T yg dynamic compensation:
T4, t5 = Time constants utilized in the Isad-lag compensator for Tavg,t4 2 28 s, t5 s 4 s:
T = Average temperature, 'F:
g{ 9 g
- Lag compensator on measured Tavg:
- s -
@' to = Time constant utilized in the measured Tavg lag compensator, t6 = 0 s:
s l2: -
?
t
=. ,'
i
l l l
I '
i
- t,
.' * , , ,f * ; , ; :! , f '. .
e r
u t
a r
e p
m
_ t e
s e
_ g s
) 3 a ;
s 0 l
l A
s e r
0
( 2 v =
1 2 t a 6 f ,
g h t
- s :
n 1 s i 7 r 8 s g T o
0 a y .
"T 2 e 3 g t a
- 1 = r c T v s t
e a n l
S
, 3 t d r
o T e p
~ m 6 T f r -
m T A T
, r o r f o m m.
- r A f o r o
+ f o r 0 t
a o c h
_ 1 r f o d s
n t
a g a
_ o r n e s l T
t a o a p n g s t ;
e e p v
)
[
n a il s r m o a
. d e 6 e p n E u c m T K t o
d
) u n T m e p W a r g c d e
A o O e a mP e it T p g g r u n d c : o l
e a v u s
n o S e g T c L m t l
- a a i r e a e T n (C A t
B u l a g A t r t e o t s d
d a M e e a d m a r C S e e l
a R g N + e r ht e r e e he E a u
(
O m u r y ht ht H
l s e s 1
n t G22 1
- I T n a n T v b n a e n A o i e a d n
- i i de ED i
d m T S r e m g e o d e d 7 o n n t n e E O t t a
iz l
o iz T i a r
ita iz o z _
s N lit A L i e s s it l l B
E + n u r o u R a
e n n it u
r o it u
A L e s t t
- 0) r e e t _
T g p p
a 9 nc a 1 _
B t a t t t n
n nm n T s n s _
A m 5 a n a T 0 i a n a
_ T K A o t s e t s A r o oc t s e t s
d c n p /. fo it n p n n d c n ic
- e g o m o e o m o 4 r u a c o c a : / F u ma c o c _
t
- _
K s l
e c f e c e
( a e
d a m g e ic : 2 md n: 0 e n m g m o e i a h y i a i T M L T L iT I
. 0 T d T L T _
A _
s _
= = = = = = = = = =
S 3
T g g g
+ _
T 2 A
1 t 1
o [
1 _
T 3 T A K4 K 5 R ' I S A t 1
t 7
t 6
1 E ' 2 W
- t _
O + + :
P e R
E " 1
( e h
r V T O A W 3
E T
w O N
n $ t c3* w Yto N ge g* w? ". #
lt!lllll l' ll' .l
. 4 Q ,. . :
TABLE 2.2-1 (Continued) '
y TABLE NOTATIONS (Continued) -
r- .
E NOTE 3: (Continued)
% o.ooiW*F
=
i Ks 6.GGG3/^F- for T > T" and Ks = 0 for T 1 T";
C
{ T = Average Temperature, "F; T" =
Indicated T,yg at RATED THERMAL POWER (Calibration temperature for aT -
instrumentation,1 588.4"F);
5 = L'a place transform operator, s 1; and e
= 0.for all al.
f(al) 2
- NOTE 4
- The channel's maximum Trip Setpoint shall not exceed its computed Trip Setpoint by more than
{ W 0f3 AT span.
- g.
2N/e 9
a 2
a 5
I M h
3 .
LIMhTINGSAFETYSYSTEMSETTINGS BASES Intermediate and Source Ranoe. Neutron Flux The Intermediate and Source Range, Neutron Flux trips provide core protection during reactor startup to mitigate the consequences of an uncontrolled rod cluster control assembly bank withdrawal from a suberitical condition. These trips provide redundant protection to the Low Setpoint trip of the Power Range, Neutron Flux chpnnels. The Source Range channels will initiate a Reactor trip at about 10 counts per second unless manually blocked when P-6 becomes active. The Intermediate Range channels will initiate a Reactor trip at a current level equivalent to approximately 25% of RATED THERMAL POWER unless manually blocked when P-10 becomes active.
Overtemoerature AT The Overtemperature AT trip provides~ core protection to prevent DNB for all combinations of pressure, power, coolant temperature, and axial power l
distribution, provided that the transient is slow with respect to piping transit delays from the core to the temperature detectors, and pressure is within the range between the Pressurizer High and Low Pressure trips. The Setpoint is automatically varied with: (1) coolant temperature to correct for temperature induced changes in density and heat capacity of water and includes dynamic compensation for piping delays from the core to the loop temperature
" detectors, (2). pressurizer pressure, and (3) axial power distribution. With normal axial power distribution, this Reactor Trip limit is always below the core Safety Limit as shown in Figure 2.1-1. If axial peaks are greater than design; as indicated by the difference between top and bottom power range nuclear detectors, the Reactor trip is automatically reduced according to the notations in Table 2.2-1.
Del ta-T as used in the Overtemperature and Overpower AT trips, represents l,he 100% RTP value as measured by the plant for each loop. For the startup of a refueled core until measured at 100% Rated Thermal Power (RTP),
Delta T is initially assumed at a value which is conservatively lower than the lasi measured 100% RTP Delta T, for each loop. This normalizes each .
loop's AT trips to the actual operating conditions existing at the time of measurement, thus forcing the trip to reflect the equivalent full power conditions as assumed in the accident analyses. These differences in vessel j AT can arise due to several factors, the most prevalent being measured RCS loop flows greater than Minimum Measured Flow, and slightly asymmetric power distributions between quadrants. While RCS loop flows are not expected to change with cycle life, radial power redistribution between quadrants may occur, resulting in small changes in loop specific vessel AT values. Accurate determination of the loop specific vessel AT value should be made when performing the Incore/Excore quarterly recalibration and under steady state conditions (i.e., power distributions not affected by Xe or other transient conditions).
> : W ERY Al Overoower AT The Overpower AT trip provides assurance of fuel integrity (e.g., no fuel pellet melting and less than 1% cladding strain) under all possible overpower conditions, limits the required range for Overtemperature AT trip, and provides a backup to the High Neutron Flux Trip.
CALLAWAY - UNIT I B 2-5 geg me hN g , 57f d
10/28/94
l INSERT Al i l
l The time constants utilized in the lag compensation of measured AT, T3, and j measured Tavg. T6, are set in the field at 0 seconds. This setting corresponds to the 7300 NLL cards used for lag compensation of these signals. Safety ,
analyses that credit Overtemperature AT for protection must account for ;
these field adjustable lag cards as well as all other first order lags (i.e., the combined RTD/thermowell response time and the scoop transport delay and thermal lag). The safety analyses use a total first order lag ofless than or equal to 6 seconds. ,
f l
i i
~
l 4
- a. .
L dMITINGSAFETYSYSTEMSETTINGS BASES 1
~
l l Overoower AT (Continued)
The Setpoint is automatically varied with: (1) coolant temperature to correct for temperature induced changes in density and heat capacity of' water, and (2) rate of change of temperature for dynamic compensation for piping delays from the core to the loop temperature detectors, to ensure that the allowable heat L
is not exceeded. The Overpower AT trip provides j t
generation protection to mitigate t consequences of various size steam breaks as rate (kW/ft) he ;
}
reported in WCAP-9226, " Reactor Core Response to Excessive Secondary Steam l
! Releases."
Delta-T as used in the Overtemperature and Overpower AT trips, represents l,he 100% RTP value as measured by the plant for each loop. For the 1 i
startup of a refueled core until measured at 100% Rated Thermal Power (RTP),
Delta T is initially assumed at a value which is conservatively lower than for each loop. This normalizes each the loop'slasl ATmeasured trips to the100%
actual RTP operaDelta T, ting conditions existing at the time of measurement, thus forcing the trip to reflect the equivalent full power conditions as assumed in the accident analyses. These differences in vessel i AT can arise due to several factors, the most prevalent being measured RCS l loop flows greater than Minimum Measured Flow, and slightly asymmetric power distributions between quadrants. While RCS loop flows are not expected to change with cycle life, radial power redistribution between quadrants may 1 occur, resulting in small changes in loop specific vessel AT values. Accurate determination of the loop specific vessel AT value should be made when performing the Incore/Excore quarterly recalibration and under steady state conditions (i.e., power distributions not affected by Xe or other transient conditions).
> ZNSER7~ A;2 Pressurizer Pressure In each of the 3ressurizer pressure channels, there are two independent bistables, each wit 1 its own Trip Setting to provide for a High and Low l Pressure trip thus limiting the pressure range in which reactor operation is permitted. The Low Setpoint trip protects against low pressure which could lead to DNB by tripping the reactor in the event of a loss of reactor coolant pressure.
On decreasing power the Low Setpoint trip is automatically blocked by P-7 (a power level of approximately 10% of RATED THERMAL POWER with turbine impulse chamber pressure at approximately 10% of full power equivalent); and l
on increasing power automatically reinstated by P-7. '
I l The High Setpoint trip functions in conjunction with the pressurizer
- . relief and safety valves to protect the Reactor Coolant System against system I overpressure.
Pressurizer Water level l The Pressurizer High Water level trip is provided to prevent water relief through the pressurizer safety valves. On decreasing power the Pressurizer
- ) High Water Level trip is automatically blocked by P-7 (a power level of l CALLAWAY - UNIT 1 B 2-6 gmendmen Ng 28 I
lhM4
i i
e INSERT A2 l The time constants utilized in the lag compensation of measured AT, T3, and l measured Tavg, T6, are set in the field at 0 seconds. This setting corresponds to the 7300 NLL cards used for lag compensation of these signals. Safety analyses that credit Overpower AT for protection must account for these field adjustable lag cards as well as all other first order lags (i.e., the combined RTD/thermowell response time and the scoop transport delay and thermal lag). The safety analyses use a total first order lag ofless than or equal to 6 seconds. ;
1 I
h i
l L
l J
l' TABLE 2.2-1 ,
Q REACTOR TRIP SYSTEM INSTRUMENTATION TRIP SETPOINTS ,.
r-5
- f TOTAL SENSOR ERROR
-< FUNCTIONAL UNIT ALLOWANCE frA) Z d) TRIP SETPOINT ALLOWABLE VALUE .
E 1. Manual Reactor Trip N.A. N.A. N.A. N.A. N. A.
z 2. Power Range, Neutron H Flux
- a. High Setpoint 7.5 4.56 0 s109% of RTP* sil2.3% of RTP*
- b. Low Setpoint 8.3 4.56 0 s25% of RTP* s28.3% of RTP*
- 3. Power Range, Neutron 2.4 0.5 0 $4% of RTP* with 56.3% of RTP* with a Flux, High Positive Rate a time constant 22 time constant 22 seconds seconds
- 4. Deleted
- 5. Intermediate Range, 17.0 8.41 0 s25% of RTP* s35.3% of RTP*
y Neutron Flux i 6. Source Range, Neutron 17.0 10.01 0 s105cps 51.6 x 105 cps Flux
- 7. Overtemperature AT 9.3 6.47 1.83 See Note 1 See Note 2
+1.24***
3 8. Overpower AT 5.0 1.90 1.65 See Note 3 See Note 4 -
B 9. Pressurizer Pressure-Low 5.0 2.21 2.0 21885 psig 21874 psig
{3 10. Pressurizer Pressure-High
- 11. Pressurizer Water Level-7.5 8.0 4.%
2.18 1.0 2.0 s2385 psig $2400 psig 592% ofinstrument 593.8% ofinstrument E., High span span z 12. Reactor Coolant Flow-Low 2.5 1.38 . 0.6 290% ofloop 288.8% ofloop minimum 9 minimum measured measured flow **
M flow *
- h
,$
- RTP = RATED THERMAL POWER
$ ** Minimum Measured Flow = 95,660 gpm
- Two Allowances (temperature and pressure, respectively)
TABLE 2.2-1 (Coenamed)
- TABLE NOTATIONS . . -
O NOTE 1: ' OVERTEMPERATURE AT r-9 1 1 + r.S) ' 1 AT(1 + riS) ' -T' ]+K3(P-P')-fi(AI) }
- :E y
- (1 + r2S)(1 + rS; s AT.(Ki-K2[(1((1+rS)T + r.Ss g Where: AT - Mea red AT; 9
. 1+rS I+rS = IMLag compensaene on measured AT; rrs - rune constama mihzed in lead-lag 2-- , - x for AT,r 2 8s,ri s 3s; I
- Las compen.aeor on measured AT; 1+rS Y rs = Tune constad utahred in the lag compensator for AT; r = Os; 9
AT. - Indicated AT W RATED THERMAL POWER;
> Ki - 1.15; 3
<t a K2 - 0.025ti'F;
-B E 1 + r.S
- The function ;;.-.-M by the lead-lag cm.---
=
x w for T,y, dynanue s--, : - m; z 1+rS 9
h r., rs = Time constams utahzed in the lead-lag a - - - for T avs.
p r. 2 28s, r, s 4s;
, T - Average ^_...,,, ofF; 1 ,
= Lag C' m
- 1+rd on measured T*'8:
1 re -
Time constant utahzed in the measured .T,yglag s ,- - s re - Oa;
(
__m_mm..--__.-m__m_mm _ _ _ _ _
-___m_m.weme,n,-
. , w mw..,, ww, , - 4 , -a-, w -,w,m , - * -
~.,,,,,,,,,,,,,,.m. -,,y. ,y,,%,,+%iw.m,,-- g , +.,- ,. v ,.
,,y__ _g. ,,. , , ,,...
, 3
'I s
TABLE 2.2-1 (CM $- .
TABLE NOTATIONS <=
NOTE 3: OVERPOWER AT ,.
r-
'5 1 r,S ' ' 1 1
- E AT(1 + riS) ' -T" ]-fi(AI) }
(1+ r S) (1+ rS; s AT.{K4-Ks (1 + r,S; (1 + r.S; T-K6(T (1+r.Ss 2
c Where: AT - Me nred AT; z
9 m 1+rS
' - te.d-1.g compen sor on me ured AT;
. 1+rS ri, r2 - rune cona m. mmzed in te.d_1.g u ---- 4 for AT, ri 2 Bs, r s 3s; 1
- Lag compensator on measured AT; 1+rS -
ra 6 r, - Time const nc uniued in ihe 1.g co apen.nor for AT,rs= 0 s; AT. - Indicased AT t RATED THERMAL POWER; K4 .. 1.090; B
"j K5 - 0.02/*F for incre.mng ver.ge ^_ r..; and 0 for decreasing aver.ge ^_..p..; .
cL
$ r,S 3 S
- The functi a gener eed by ihe r ne-1.g : ----, ; --- for T ygdyn.nnec. . w ,
2 9
g r, - Time const.nt unlued in the r% h, - . for T ,y,, r to.;
h ab
_ _ _ _ _ _ . _ _ _ _ _ _ _ _ . _ _ _ _ .- .- . . . - - . . . . - , . _ - _ _ . _. . . - . _ . _-. ~. . . . . . _ . _ . _ _ _ . _ .
4 I TABLE 2.2-1 (Com=M -
TABLE NOTATIONS .
Q g NOTE: 3 (Continued)
Q l = "y on measured T ava; Lag h ,,-
I 1+r.S
- r. nme constant utilized in ihe measured T,ygtag cwip-av, r.= 0s; z
} Ks -
- o. cots /*F for T > T" and Ks - o for T s T":
T - Average T, ,~.e , *F; T" - Indicated T avg at RATED THERMAL POWER (Calibration ,te..- ~.eo for AT instrumentanon, s 588.4*F);
S - Lapiace transform operator, c1; and y fi(AI) - o for an AI. ;
O NOTE 4: The channel's mannum Trip Setpome shall not exceed its computed Trip Scepomt by more than 2.4 % of AT span.
l B
w 1 3
Q.
3-w .
z 9
M y
as M
i
__._ _ . _ _ _ _ _ _ _ _ _ _ _ _ . . - . , . - . . - . . . - - . . ,-___-. . . - . - , , _. _ , . . - . -- . . ~ . - . . . _ . _ . . - . . . . .. , ,
o
- LIMITING SAFETY SYSTEM SETTINGS BASES Intermediate and Source Ranoe. Neutron Flux The Intermediate and Source Range, Neutron Flux trips provide core protection during reactor startup to mitigate the consequences of an uncontrolled rod cluster control assembly bank withdrawal from a subcritical condition. These trips provide redundant protection to the Low Setpoint trip of the Power Range, Neutron Flux channels. The Source Range channels will initiate a Reactor trip at about 105 counts per second unless manually blocked when P-6 becomes active. The Intermediate Range channels willinitiate a Reactor trip at a current level equivalent to approximately 25%
of RATED THERMAL POWER unless manually blocked when P-10 becomes active.
Overtemoerature AT The Overtemperature AT trip provides core protection to prevent DNB for all combinations of pressure, power, coolant temperature, and axial power distribution, provided that the transient is slow with respect to piping transit delays from the core to the temperature detectors, and pressure is within the range between the Pressurizer High and Low Pressura trips. The Setpoint is automatically varied with: (1) coolant temperature to correct for temperature induced changes in density and heat capacity of water and includes dynamic compensation for piping delays from the core to the loop temperature detectors, (2) pressurizer pressure, and (3) axial power distribution. With normal axial power distribution, this Reactor Trip limit is always below the core Safety Limit as shown in Figure 2.1-1. If axial peaks are greater than design, as indicated by the difference between top and bottom power range nuclear detectors, the Reactor trip is automatically reduced according to the notations in Table 2.2-1.
Delta-T., as used in the Overtemperature and Overpower AT trips, represents the 100% RTP value as measured by the plant for each loop. For the startup of a refueled core until measured at 100% Rated Thermal Power (RTP), Delta T. is initially assumed at a value which is conservatively lower than the last measured 100% RTP Delta T. for each loop. This normalizes each loop's AT trips to the actual operating conditions existing at the time of measurement, thus forcing the trip to reflect the equivalent full power conditions as assumed in the accident analyses. These differences in vessel AT i can arise due to several factors, the most prevalent Leing measured RCS loop flows greater than Minimum Measured Flow, and slightly asymmetric power distributions between quadrants. While RCS loop flows are not expected to change with cycle life, radial power redistribution between quadrants may occur, resulting in small changes in loop specific vessel AT values. Accurate determination of the loop specific vessel AT )
value should be made when performing the Incore/Excore quarterly recalibration and !
under steady state conditions (i.e., power distributions not affected by Xe or other transient conditions).
l The time constants utilized in the lag compensation of measured AT, 73, and I measured T 7300 NLL av carks, r.,for used arelagset in the field ofatthese compensation 0 seconds.
signals. This Safetysetting corresponds analyses that credit to the CALLAWAY - UNIT 1 B 2-5 Amendment No. GB,67 Revised by letter of 10/28/94
o *o
, LIMITING SAFETY SY:lIEM SETTINGS ,
BASES .
Overtemperature AT (Continued)
Overtemperature AT for protection must account for these field adjustable lag cards as well as all other first order lags (i.e., the combined RTD/thermowell response time and the scoop transport delay and thermal lag). The safety analyses use a total first order lag of less than or equal to 6 seconds.
Overoower AT The Overpower AT trip provides assurance of fuel integrity (e.g., no fuel pellet melting and less than 1 % cladding strain) under all possible overpower conditions, limits -
the required range for Overtemperature AT trip, and provides a backup to the High Neutron Flux Trip.
CALLAWAY - UNIT 1 B 2-5a Amendment No. G8,57 Revised by letter of 10/28/94
, c. .
LibilTING SAFETY SYSTEM SETTINGS BASES Overoower AT (Continued)
The Setpoint is automatically varied with: (1) coolant temperature to correct for temperature induced changes in density and heat capacity of water, and (2) rate of change of temperature for dynamic compensation for piping delays from the core to the loop temperature detectors, to ensure that the allowable heat generation rate (kW/ft) is not exceeded. The Overpower AT trip provides protection to mitigate the consequences of various size steam breaks as reported in WCAP-9226, " Reactor Core Response to Excessive Secondary Steam Releases."
Delta-T., as used in the Overtemperature and Overpower AT trips, represents the 100% RTP value as measured by the plant for each loop. For the startup of a refueled core until measured at 100% Rated Thermal Power (RTP), Delta T. is initially assumed at a value which is conservatively lower than the last measured 100% RTP Delta T. for each loop. This normalizes each loop's AT trips to the actual operating conditions existing at the time of measurement, thus forcing the trip to reflect the equivalent full power conditions as assumed in the accident analyses. These differences in vessel AT can arise due to several factors, the most prevalent being measured RCS loop flows greater than Minimum Measured Flow, and slightly asymmetric power distributions between quadrants. While RCS loop flows are not expected to change with cycle life, radial power redistribution between quadrants may occur, resulting in small changes in loop specific vessel AT values. Accurate determination of the loop specific vessel AT value should be made when performing the Incore/Excore quarterly recalibration and under steady state conditions (i.e., power distributions not affected by Xe or other transient conditions).
The time constants utilized in the lag compensation of measured AT, n, and measured Ta vg, r., are set in the field at 0 seconds. This setting corresponds to the 7300 NLL cards used for lag compensation of these signals. Safety analyses that credit Overpower AT for protection must account for these field adjustable lag cards as well as ,
all other first order lags (i.e., the combined RTD/thermowell response time and the scoop transport delay and thermallag). The safety analyses use a total first order lag of less than or equal to 6 seconds.
Pressurizer Pressurg in each of the pressurizer pressure channels, there are two independent bistables, each with its own Trip Setting to provide for a High and Low Pressure trip thus limiting the pressure range in which reactor operation is permitted. The Low Setpoint trip protects against low pressure which could led to DNB by tripping the reactor in the ;
event of a loss of reactor coolant pressure, j CALLAWAY - UNIT 1 B 2-6 Amendment No. 28 Revised by letter of l 10/28/94
~ ~ ..
. LibilTING SAFETY SYSTEM SETTINGS BASES ,_
Pressurizer Pressure (Continued)
On decreasing power the Low Setpoint trip is automatically blocked by P-7 (a power level of approximately 10% of RATED THERMAL POWER with turbine impulse chamber pressure at approximately 10% of full power equivalent); and on increasing power, automatically reinstated by P-7.
The High Setpoint trip functions in conjunction with the pressurizer relief and safety valves to protect the Reactor Coolant System against system overpressure.
Pressurizer Water Level The Pressurizer High Water Level trip is provided to prevent water relief through the pressurizer safety valves. On decreasing power the Pressurizer High Water Level trip is automatically blocked by P-7 (a power level of CALLAWAY - UNIT 1 B 2-6a Amendment No. 28 Revised by letter of 10/28/94
--