ML20196B812
| ML20196B812 | |
| Person / Time | |
|---|---|
| Site: | South Texas  |
| Issue date: | 11/23/1998 |
| From: | HOUSTON LIGHTING & POWER CO. |
| To: | |
| Shared Package | |
| ML20196B810 | List: |
| References | |
| NUDOCS 9812010190 | |
| Download: ML20196B812 (4) | |
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g 3/4.7 PLANT SYSTEMS l-3/4.7.1 TURBINE CYCLE rj i
SAFETY VALVES I
LIMITING CONDITION FOR OPERATION 3.7.1.1. All main steam lihe' Code safety valves associated with each steam l
generator shall be OPERABLE with lift settings as specified in Table 3.7-2.
APPLICABILITY: MODES 1, 2, and 3.
ACTION:
With four reactor coolant loops and associated steam generators in a.
operation and with one or more main steam line Code safety valves i
inoperable, operation in MODES 1, 2, and 3 may proceed provided that within 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br />, either the inoperable valve is restored to OPERABLE l
status or the Power Range Neutron Flux High Trip Setpoint is reduced j
l per Table 3.7-1; otherwise, be in at least HOT STAN0BY within the I
next 6 hours6.944444e-5 days <br />0.00167 hours <br />9.920635e-6 weeks <br />2.283e-6 months <br /> and in COLD SHUTOOWN within the following 30 hours3.472222e-4 days <br />0.00833 hours <br />4.960317e-5 weeks <br />1.1415e-5 months <br />.
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The provisions of Specification 3.0.4 are not applicable.
SURVEILLANCE RE0UIREMENTS i
4.7.1.1 There are no additional requirements other than those required by 1
Specification 4.0.5 I
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S'00TH TEXAS - UNITS 1 & 2 3/4 7-1 Unit 1 - Amendment No. / 59 Unit 2 - Amendment No. 47 j-J
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TABLE 3.7-1 MAXIMUM ALLOWABLE POWER RANGE NEUTRON FLUX HIGH SETPOINT WITH INOPERABLE STEAM LINE SAFETY VALVES DURING 4 LOOP OPERATION MAXTAUM NLNBER OF INOPERABLE MAXIMUM ALLOWABLE POWER RANGE SAFETY VALVES ON ANY NEUTRON FLUX HIGH SETPOINT
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OPERATING STEAM GENERATOR (PERCENT OF RATED THERMAL POWER) 1 63 2
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SOUTH TEXAS - UNITS I & 2 3/4 7-2 Unit I - Amendment No. 66 Unit 2 - Amendment No. 55
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TABLE 3.7-2 STEAM LINE SAFETY VALVES PER LOOP I_
l VALVE NUMBER LIFT SETTING' (13%)2
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f LOOP A' LOOP B LOOP C LOOP D 1.
PSV-7410 PVS-7420 PSV-7430 PSV-7440 1285 psig 16 n.2 2.
PSV-7410A PVS-7420A PSV-7430A PSV-7440A 1295 psig 16 2
3.
PSV-741CB PiS-7420B PSV-7430B PSV-74408 1305 psig 6i.
4.
PSV-7410C'PVS-7420C PSV-7430C PSV-7440C 1315 psig in 5.
PSV-7410D PVS-74200 PSV-74300 PSV-7440D 1325 psig in.
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'The lift setting pressure shall correspond to ambient conditions of the valve l
at nominal operating temperature and pressure.
The as left lift setting shall be within 114 following valve, testing.
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SOUTH TEXAS - UNITS-1 & 2 3/4 7-3 Unit 1 - Amendment No. 78 Unit 2 - Amendment No. 67
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3/4.7.1 TURBINE CYCLE l
3/4.7.1.1 SAFETY VALVES l
The OPERABILITY of the main steam line Code safety valves ensures that the Secondary System pressure will be limited to within 110% (1413.5 psig) of i
its design pressure of 1285 psig during the most severe anticipated system operational transient. The maximum relieving capacity is associated with a i
Turbine trip from 100% RATED THERMAL POWER coincident with an assumed loss of j
condenser heat sink (i.e., no steam bypass to the condenser).
l The specified valve lift settings and relieving capacities are in
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accordance with the requirements of Section III of the ASME Boiler and j
Pressure Code, 1971 Edition. The to}al relieving capacity for all valves on all of the steam lines is 20.65 x i
secondary steam flow of 16.94 x 10l0 lbs/h which is 122% of the total lbs/h at 100% RATED THERMAL POWER. A ninimum of two OPERABLE safety valves per steam generator ensures that sufficient relieving capacity is available for the allowable THERMAL POWER restriction in Table 3.7-1.
STARTUP and/or POWER OPERATION is allowable with safety valves inoperable within the limitations of the ACTION requirements on the basis of the reduction in Secondary Coolant System steam flow and THERMAL POWER required by the reduced Reactor trip settings of the Power Range Neutron Flux channels.
The Reactor Trip Setpoint reductions are derived on the following bases:
Hit - (100) (w,h,,N)
Q K
Where:
Hi @ - Safety analysis power range high neutron flux setpoint, percent Q
= Nominal NSSS power rating of the plant (including reactor coolant pump heat), MWt K
- Conversion Factor, 947.82 (B W/sec)/MWt w,
- Minimum total steam flow rate capability of the operable MSSVs on any one steam generator at the highest MSSV opening pressure, including tolerance and accumulation, as appropriate, in 1bm/sec. For example, if the maximum number of inoperable MLSVs on any one steam generator is one, then w, should be a
If the maximum number of inoperable MSSVs per steam generator is three, then w should.be a summation of the capacity of the operable MSSVs al the highest operable MSSV operating pressure, excluding the three highest capacity MSSVs.
h,, - Heat of vaporization for steam at the highest MSSV operating pressure including allowances for tolerance, drift, and accumulation, as appropricte, Btu /lbe N
- Number of loops in the plant.
The calculated values are lowered an additional 9% full power to account for instrument and channel uncertainties.
SOUTH TEXAS - UNITS 1 & 2 B 3/4 7-1 Unit 1 - Amendment No. 66
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