ML20217D053
| ML20217D053 | |
| Person / Time | |
|---|---|
| Site: | South Texas  |
| Issue date: | 09/30/1999 |
| From: | HOUSTON LIGHTING & POWER CO. |
| To: | |
| Shared Package | |
| ML20217D047 | List: |
| References | |
| NUDOCS 9910140166 | |
| Download: ML20217D053 (13) | |
Text
_
. . j l
l N pe MMY l
SOUTII TEXAS PROJECT ELECTRIC GENERATING STATION UNIT 2 CYCLE 7 CORE. OPERATING LIMITS REPORT Revision 1 September 1999 9910140166 990930 PDR ADOCK 05000498 P PDR Core Operating Limits Report. Rev i September 1999
F .
South Texas Project Unit 2 Cycle 7 1.0 CORE OPERATING LIMITS REPORT This Core Operating Limits Report for STPEGS Unit 2 Cycle 7 has been prepared in accordance with the requirements of Technical Specification 6.9.1.6. The core operating limits have been developed using the NRC-approved methodologies specified in Technical Specification 6.9.1.6.
l
- The Technical Specifications affected by this report are: !
l
- 1) 2.1 SAFETY LIMITS
- 2) 2.2 LIMITINO SAFETY SYSTEM SETTINGS l
- 3) 3/4.1.1.3 MODERATOR TEMPERATURE COEFFICIENT LIMITS !
- 4) 3/4.1.3.5 SHUTDOWN ROD INSERTION LIMITS
- 5) 3/4.1.3.6 CONTROL RODINSERTION LIMITS
- 6) 3/4.2.1 AFD LIMITS l 7) 3/4.2.2 HEAT FLUX HOT CHANNEL FACTOR
! 8) 3/4.2.3 NUCLEAR ENTHALPY RISE HOT CHANNEL FACTOR l
- 9) 3/4.2.5 DNB PARAMETERS ,
l 2.0 OPERATING LIMITS COLR Section 2.8 provides for an alternate minimum measured Reactor Coolant System flow limit consistent with plugging up to 10% of steam generator tubes and Departure from Nucleate Boiling requirements. When using the alternate minimum flow limit, the Tava limit is reduced for RCS flow no less than 380,500 gpm, Setpoint and constant values for OPAT and OTAT are also revised accordinely when this alternate mode of operation is entered.
, The cycle-specific parameter limits for the specifications listed in Section 1.0 are presented below.
l 2.1 SAFETY LIMITS (Specification 2.1) 2.1.1- The combination of THERMAL POWER, pressurizer pressure, and the highest operating loop coolant temperature (T ) shall not exceed the limits shown in Figure 1, or in Figure 2 when operating under alternate operating criteria consistent with reduced Reactor Coolant System flow as addressed in COLR Section 2.8.
Core Operating Lirnits Report. Rev i September 1999 l Page 2 of 13 l
4 South Texas Project Unit 2 Cycle 7 2.2 LIMITING SAFETY SYSTEM SETTINGS (Specification 2.2) 2.2.1 The Loop design flow for Reactor Coolant Flow-Low is 95,400 gpm (or 92,500 gpm for alternate operation with reduced RCS flow).
2.2.2 The Over Temperature AT and Overpower AT setpoint parameter values are listed below:
Overtemperature AT Setpoint Parameter Values Ti ; measured reactor vessel AT lead / lag time constant, Ti = 8 sec T2; measured reactor vessel AT lead / lag time constant, T2 = 3 sec T3; measured reactor vessel AT lag time constant, T3 = 0 see T4; measured reactor vessel average temperature lead / lag time constant, T4 = 28 see T5; measured reactor vessel average temperature lead / lag time constant, T5 = 4 sec T6; measured reactor vessel ave: age temperature lag time constant, T6 = 0 sec ,
Ki; Overtemperature AT reactor trip setpoint, Ki = 1.14; or , Ki = 1.13 for altemate operation with reduced RCS flow K2; Overtemperature AT reactor trip setpoint Tavg coefficient, K2 = 0.028/ F K3 ; Overtemperature AT reactor trip setpoint pressure coefficient, K 3= 0.00143/psig T'; Nominal full power Tavg, T' 5; 589.0 *F (including altemate operation with reduced RCS flow) i P'; Nommal RCS pressure, P' = 2235psig f i(AI) is a function of the indicated difference bctween top and bottom detectors of the power-range neutron ion chambers; with gains to be ,
selected based on measured instrument response during plant startup tests such that; (1) For gi - qd between -70% and +8%, or +6% for altemate operation with reduced RCS flow, fi(AI) = 0, where qi and qs are percent RATED THERMAL POWER in the top and bottom halves of the Core Operating Limits Report, Rev 1 September 1999 Page 3 of 13
South Texas Project Unit 2 Cycle 7 core respectively, and gi + qdi s total THERMAL POWER in percent of RATED THERMAL POWER; (2) For each percent that the magnitude of gi- qs. exceeds -70%, the AT Trip Setpoint shall be automatically reduced by 0.0% ofits value at RATED THERMAL POWER; and (3) For eacia percent that the magnitude of qt - qu exceeds +8%, or +6%
for attemate operation with reduced RCS flow, the AT Trip Setpoint I shall be automatically reduced by 2.65% ofits value at RATED THERMAL POWER.
Overpower AT Setpoint Parameter Values n; measured reactor vessel AT lead / lag time constant, q = 8 sec T2; measured reactor vessel AT lead / lag time constant, T2 = 3 sec i
n ; measured reactor vessel AT lag time constant, n = 0 sec I T6; measured reactor vessel average temperature lag time constant, T6 = 0 sec !
l 1
T7; Time constant utilized in the rate-lag compensator for T.yg, t7 = 10 sec k; Overpower AT reactor trip setpoint, K4 = 1.08; (or k = 1.07 for alternate ;
operation with reduced RCS flow)
K5; Overpower AT reactor trip setpoint Tavg rate / lag coefficient, K 5 = 0.02/ F for increasing average temperature, and K5 = 0 for decreasing average temperature k; Overpower AT reactor trip setpoint Tavg heatup coeflicient k = 0.002/ F for T > T" and, k = 0 for T s T" T"; Indicated full power Tavg, T" s 589.0 F (including altemate operation with reduced RCS flow) f2(AI) = 0 for all(AI) 2.3 MODERATOR TEMPERATURE COEFFICIENT (Specification 3.1.1.3):
2.3.1 The BOL, ARO, MTC shall be less positive than the limits shown in Figure 3.
Core Operaung Limits Report, Rev i September 1999 Page 4 of 13
r-South Texas Project Unit 2 Cycle 7 4
2.3.2 The EOL, ARO, HFP, MTC shall be less negative than -6.12 x 10 Ak/k/ F.
2.3.3 The 300 ppm, ARO, HFP, MTC shall be less negative than -5.22 x 104 Ak/k/ F (300 ppm Surveillance Limit).
where: BOL stands for Beginning-of-Cycle Life EOL stands for End-of-Cycle Life ARO stands for All Rods Out HFP stands for Hot Full Power (100% RATED THERMAL FOWER)
HFP vessel average temperature is 589 F 2.4 ROD INSERTION LIMITS (Specification 3.1.3.5 and 3.1.3.6):
2.4.1 All banks shall have the same Full Out Position (FOP) of at least 250 steps withdrawn but not exceeding 259 steps withdrawn.
2.4.2 The Control Banks shall be limited in physical insertion as specified in Figure 4.
2.4.3 Individual Shutdown bank rods are fully withdrawn when the Bank Demand Indication is at the FOP and the Rod Group Height Limiting Condition for Operation is satisfied (T.S. 3.1.3.1).
l 2.5 AXIAL FLUX DIFFERENCE (Specification 3.2.1):
l 2.5.1 AFD limits as required by Technical Specification 3.2.1 are determined by l CAOC Operations with an AFD target band of+3, -12%.
2.5.2 The AFD shall be maintained within the ACCEPTABLE OPERATION l portion of Figure 5, as required by Technical Specifications.
2.6 HEAT FLUX HOT CHANNEL FACTOR (Specification 3.2.2):
2.6.1 FT = 2.55.
2.6.2 K(Z)is provided in Figure 6.
2.6.3 The Fxy limits for RATED THERMAL POWER (FRg ) within specific core planes shall be:
2.6.3.1 Less than or equal to 2.102 for all core planes containing Bank "D" control rods, and 2.6.3.2 Less than or equal to the appropriate core height-dependent value from Table 1 for all unrodded core planes.
2.6.3.3 PFxy == 0.2.
These F,y limits were used to confirm that the heat flux hot channel factorFn(Z) will be limited by Technical Specification 3.2.2 assuming the most-limiting axial power Core Operating Limits Repon Rev i September 1999
r l South Texas Project l Unit 2 Cycle 7 p
distributions expected to result for the insertion and removal of Control Banks C and D during operation, including the accompanying variations in the axial xenon l and power distributions, as described in WCAP-8385. Therefore, these F,y limits l provide assurance that the initial conditions assumed in the LOCA analysis are met, along with the ECCS acceptance criteria of 10 CFR 50.46.
For Unit 2 Cycle 7, the L(Z) penalty is not applied (i.e., L(Z) = 1.0 for all core elevations).
2.7 ENTHALPY RISE HOT CHANNEL FACTOR (Specification 3.2.3):
Standard Fuel VANTAGE SH / VANTAGE + / RFA Fuel 2.7.1 FW = 1.49 FW = 1.557 2.7.2 PFm = 0.3 - PFm = 0.3 2.8 DNB PARAMETERS (Specification 3.2.5) 2.8.1 The following DNB-related parameters shall be maintained within the following limits:
- a. Reactor Coolant System Tog,s 595 F* l (or s 593 F* with reduced RCS flow of COLR 2.8.1.c)
- b. Pressurizer Pressure, > 2219 psig* *
- c. Minimum Measured Reactor Coolant System Flow 2 392,300 gpm***
(or3 380,500 gpm* ** with reduced RCS Tasof COLR 2.8.1.a)
- Includes a 1.9 'F measurement uncertainty.
" Limit not applicable during either a "Ihermal Power ramp in excess of 5% of RTP per minute or a Thennal Power step in excess of 10% RTP. Includes a 28.4 psi measurement uncertainty.
"* Includes a 2.8% flow measurement uncertainty.
3.0 REFERENCES
3.1 Letter from N. R. Metcalf(Westinghouse) to Dave Hoppes (STPNOC), " Unit 2 Cycle 7 Core Operating Limits Report," 98TG-G-0064 (ST-UB-NOC-1840), October 12,1998.
! 3.2 NUREG-1346, Technical Specifications, South Texas Project Unit Nos. I and 2.
l 3.3 STPNOC Calculation ZC-7035, Rev.1," Loop Uncertainty Calculation for RCSTavg Instrumentation", 10-19-1998 3.4 STPNOC Calculation ZC-7032, Rev.1," Loop Uncertainty Calculation for Narrow Range Pressurizer Pressure Monitoring Instrumentation",6-10-1999.
I Core Operating Limits Report, Rev 1 September 1999 Page 6 of 13 l
t
South Texas Project Unit 2 Cycle 7 Figure 1 Reactor Core Safety Limit - Four Loops in Operation 680 l l
l UNACCEPTABLE (0.02,663.54) 660 '
'N 'N g d J
-(0.02,660 46) N N N %
% N
_ N N N N
- (0'02,650 94)N-' A '
A
% N N g (1.00.636.50) 640 N g 2400 PSIA A N N
%_ N N m (
% A (0.02.633.87) N- g 2250 PStA N g N
N
-- (1.00.633.01) (\\
% % s 1
' ^
s * % N l
$ 620 '
s x * (i.o4.620mD 3
E
- (0 m.aus>Nx ,, ,3, N
N \, \
> -s N s N 3
4 m w \ <
's N g( ,
0 600 1830 PSIA DA N (1.30.600.39)
E N %
' s s \ (i.30.ss7.6s>
N N g (1.30,589.25)
N N k 580 (1.14,585.75)
\
A CC EPTABLE \ \ ,,,,,,,,
% t ._
(1 2 ,664.71) 560 4
' I i, - t
-[ . .
.._j q ._ 2 l
I ' '
540 0 0.2 0,4 0.6 0.8 1 1.2 l
Fraction of RATED THERMAL POWER Core Operating Umits Report, Rev 1 September 1999 Page 7 of 13
[
l South Texas Project Unit 2 Cycle 7
)
Figure 2 Reactor Core Safety Limit - Four Loops in Operation (Alternate) 680 s o2.u 44a) UNACCEPTABLE 660 - Q% x
-(o o2mt.so)D [N G PSIA 2
N 0 02.8s2 o7) s N N
N
%~xK[
2400 esiA N N s
640 s % q h s m ee2.s38 4e)
N. N %
N N 2250 PSIA N N
%._ _ (om.632.61) b (0 02.634.se)g % N 4
^ '%.
n %
- u. 620 2N * - \
N g N g (1.00s.621.26) f e
w en g
-(o 02.622.37) -N N g
s~N 2000 PSIA N
N g s
's
'\ _
r ~ s _. _
h600 e
1830 Pd:D N s gs N ,
N m w
s \(- N (s m.5952)
N w \ \
N \ (130.ss7.2s) 580 ACCEPTABLE o.ur.ses 723 \ \ l
\ \ >
o m.s73.34)
\
560 - - - -
- r- -,-
_ g _. . . . . _
_ _,a __. _
- .s !
._ _ . .! _... .i .
i MO '
! 0 0.2 0.4 0.6 0.8 1 1.2 i
Fraction of RATED THERMAL POWER Core Operating Limits Report, Rev 1 September 1999 Page 8 of 13 l
i
(
{ South Texas Project Unit 2 Cycle 7 Figure 3 MTC versus Power Level 1
70 '
- Ehg >. ~i?$$?$$$$$$bh w ^ t*
6.0 [~ -
UNACCEPTABLE OPERATION
...~ -
.* r.w -
z ~% '- s. ~cw~ .-- -
5.0 l
l we.w 4.0 7; 3
l V', ,. .. .
3.0. : o' 'c C .
) ,
% 7 ~~ " y i E '
l
- 8. 2.0 O -
g ACCEPTABLE OPERATION 1.0 Y l O.0 1
l
-1.0 i
1
-2.0 l
1 0
-3'0 100.0 O.0 20.0 40.0 60.0 80.0 l Relative Power (%)
l l
Core Operating Limits Report, Rev i September 1999 j Page 9 of 13 l
l \
l 1
T' I
South Texas Project Unit 2 Cycle 7 l Figure 4 j 1 '
, 1 L
- Control Rod Insertion Limits versus Power Level fPower, FOP)e Ovarino (23,259): 122 Step overlap i r (23,258): 121 Step overlap 260 ,
l / (22,256)s 119 Step overlap / )
l ,
/ (21,254): 117 Step overlap ,
/ ,
240 ,
/ l ,
/ l 7 7
,r fPower. FOP)t Overlan ;
/ . . / (79,259): 122 step overlap l
' ' f (79,258): 121 Step overlap 220 / /
/ / (78,256): 119 step overlap !
l
/ ,
/ (77,254): 117 step overlap 1 r l 200 - 40,202 l /
/
h 4
A ,
180 ,
/ l100,174 H
/ )
. / )
I 160
$ f iRAIGt C i j i )
140 i '
f ,
m i /
g i /
120 f y .
) / i
) / \
l 100
)
A f
p
~~
/ / IBMut D I ._[
80 , ,
==
/ .f 60 g
j....
e,6s
- n. y
.r r
.f
/
f 40 7
/
f s
r
.. 20 ,/
/
r ,___,
Q 2' O 10 20 30 40 50 60 70 80 90 100 REIATIVE POWER (%)
Coatest Bank A is already withdrawn to Fun Out Position.
Core Operating Limits Report. Rev 1 September 1999 Page 10 of 13 i
l 1
l
[. .
South Texas Project Unit 2 Cycle 7 l-l Figure 5 AFD Limits versus Rated Thermal Power
-120 100 l - 11, 9 01 l11,90l
~~
UNACCEPTABLE ! \ UNACCEPTABLE p OPERATION / T OPERATION
- 8o
/ N .
i e 3 O J q
/ \
f \
R " > <
j /
/ \
h e ; ACCEPTABLE (
$ OPERATION g I-31,50! !31,50!
40 20 0
-50 -40 30 -20 -10 0 10 20 30 40 50 j Flux Dif ference (AI) % l l
l l
Core Operating Limits Report, Rev 1 - September 1999 Page 11 of 13
r
+ .
South Texas Project Unit 2 Cycle 7
! Figure 6 K(Z) - Normalized Fo(Z) versus Core IIcight l
}
1.2 E1 x
of O
y0.8 5
e E
E 0.6 6
8- Core Elevation FQ K(Z) 0.0 ft 2.55 1.0
$ 04 ~
7.0 ft 2.55 1.0 l
d 14.0 ft 2.359 0.925 E
a:
@ 0.2 0 14.0 0.0 7.0 CORE HEIGHT (FT) l
(
Core Operating Limits Report, Rev i September 1999
II
' l South Texas Project !
Unit 2 Cycle 7 Table 1 l
, Unrodded F,y for Each Core Height Core Height Unrodded Core Height Unrodded (Ft.) Fxy- (Ft.) Fxy_ l 14.000 3.443 6.800 1.905 13.800 3.125 6.600 1.907 13.600 2.793 6.400 1.909 13.400 2.453 6.200 1.911 13.200 2.193 6.000 1.909 13.000 2.032 5.800 1.905 l 12.800 1.987 5.600 1.90' 12.600 1.975 5.400 1.907 12.400 1.983 5.200 1.916 12.200 1.985 5.000 1.923 12.000 1.994 4.800 1.929 j 11.800 2.007 4.600 1.926 11.600 2.029 4.400 1.923 ;
11.400 2.024 4.200
=
1.924 11.200 2.000 4.000 1.927 11.000 1.949 3.800 1.937 )
10.800 1.918 3.600 1.951 10.600 1.899 3.400 1.945 10.400 1.892 3.200 1.929 !
10.200 1.889 3.000 1.908 i 10.000 1.886 2.800 1.886 I 9.800 1.883 2.600 1.862 9.600 1.878 2.400 1.844 9.400 1.872 2.200 1.831 9.200 1.866 2.000 1.816 ,
9.000 1.861 1.800 1.805 8.800 1.857 1.600 1.788 ,
8.600 1.855 1.400 1.786 l 8.400 1.854 1.200 1.777 8.200 1.857 1.000 1.779 8.000 1.862 0.800 1.896
'7.800 1.872 0.600 2.113 7.600 1.884 0.400 2.381 7.400 1.895 0.200 2.643 7.200 1.901 0.000 2.893 7.000 1.903 For Unit 2 Cycle 7, the L(Z) penalty is not applied (i.e., L(Z) = 1.0 for all core elevations).
Core Operating Limits Report, Rev i September 1999 i
Page 13 of 13