ML20211C037
| ML20211C037 | |
| Person / Time | |
|---|---|
| Site: | South Texas  |
| Issue date: | 08/18/1999 |
| From: | HOUSTON LIGHTING & POWER CO. |
| To: | |
| Shared Package | |
| ML20211C027 | List: |
| References | |
| NUDOCS 9908250145 | |
| Download: ML20211C037 (13) | |
Text
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NOC-AB-000521 Page 4 of 7 REACTOR C0OLANT SYSTEM OVERPRESSURE PROTECTION SYSTEMS LIMITING CONDITION FOR CPERATION j
Au 3.4.9.3 At h ::t ::: Of th: f0thuki;)verpressure Protection System [shall beOPERABLp IMsLh,T$
a.
Two power-operated relief valves (PORVs) with lift settings which do not exceed the limit established in Figure 3.4-4, or b,
The Reactor Coolant System (RCS) depressurized with an RCS vent of greater than or equal to 2.0 square inches.
APPLICABIL1TY: H0 DES 4 and S. and MODE 6 when the head is on the reactor vesse1 Nh ACTION:
rusenr2 t.
Witd one PORY inoperable in H0DE 4 restore the inoperable PORV to *
}
'c.
OPERABLE status within 7 days or depressurize and vent the RCS through at least a 2.0 square inch vent within the next 8 hours9.259259e-5 days <br />0.00222 hours <br />1.322751e-5 weeks <br />3.044e-6 months <br />.
g.
With one PORV inoperable in MODES 5 or 6 with the head on the reactor J
d.
vessel, restore the inoperable PORV to OPERABLE status within 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br />, or complete depressurization and venting of t through at least agsquare i ch vent within the next 8 hour9.259259e-5 days <br />0.00222 hours <br />1.322751e-5 weeks <br />3.044e-6 months <br /> J,
g f.
With both PORVs inoperable, depressurize and v the RCS through
[
e.
at least a 2.0 square inch vent within 8 hours9.259259e-5 days <br />0.00222 hours <br />1.322751e-5 weeks <br />3.044e-6 months <br />, f
In the event either the PORVs or the RCS vent (s) are used to mitigate j{d an RCS pressure transient, a Special Report shall be prepared and submitted to the Commission pursuant to Specification 6.9.2 within 30 days. The report shall describe the circumstances initiating the transient, the effect of the PORVs or RCS vent (s) on the transient, and any corrective action necessary to prevent recurrence, f.
The provisions of Specification 3.0.4 are not applicable.
l S-MisACTIONmarbesuspendedforupto7daystoallowfunctionaltestingto j
y verify PORV operability. During this test period, operation of systems or i
components which could teruit in an RCS mass or temperature increase wi)) be administrative 1y controlled. During the ASME stroke testing of two inoperable RswdATE PORVs, cold overpressurization mitigation will be provided by two RHR discharge pg relief valves associated with two OPERABLE and operating RHR loops which have the auto closure interlock bypassed [or deleted). If one PORY is inoparable, Pc. 3# 4 38 cold overpressure mitigation will be provided by the OPERABLE PORV and one RHR discharge relief valve associated with an OPERABLE and operating RHR loop which has the auto closure interlock bypassed (or deleted).
""m uva - imiTS 1 I. 2 3/4 4-36 Unit 1 - Amendment No. 31 6nM 2 - Am 3wat it 22 9908250145 990818 PDR ADOCK 05000498 i
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4 NOC-AB-000521 R e u es. hh m 6 k uar
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(CN A/EX Y PAGE)
THE 2 PUWP AND 4 PUWP CUmS Coom AT OREATER THAN OR EQUAL TO 20oY soo
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soo 100 200 400 TRTD - AUCT10NEERED LOW WEASURED RCS TEMPERATURE 'F)
(IoEND 2 PUWP 4 PUMP OPERA o-toas m e new.
FIGURE 3.4-4 NOMINAL MAXIMUM ALLOWABLE PORV SETPOINT FOR THE COLD OVERPRESSURE SYSTEM SOUTH TEXAS - UNITS 1 & 2 3/4 4-37 Unit 1 - Amendment No. 63 Unit 2 - Amendment No. 52
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NOC.AB 000521 MAXIMUM ALLOWABLE PORV SETPOINT Page 6 of 7 i
TE 2 PUhr AND 4 FUF CURVES CDNODE AT GREATER THAN 200 083 F i
i 750 i
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& 700.
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i 650.
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j 600. _......;.............. $........
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g 500 1
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50 100 150 250 300 350 400 T.. AUCTICNBED LOW MEASUPUE RC8 TEMPERATLRE(D83 F)
...... 4 FU@ ORRATION 2 PUNPCHRATION kEPL A CE Mf KIT. bra tr)I And FDL*.
Smue.G.3. 4-4 en AtGE 3/4 4-37 I
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NOC-AE-000521 Page 7 of 7 REACTOR COOLANT SYSTEM OVERPRESSURE PROTECTION SYSTEMS SURVEILLANCE REOUIREMENTS 4.4.9.3.1 Each PORV shall be demonstrated OPERABLE by:
Performance of an ANALOG CHANNEL OPERATIONAL TEST on the PORV a.
actuation channel, but excluding valve operation, within 31 days prior to entering a condition in which the PORV is required OPERABLE and at least once per 31 days thereafter when the PORV is required OPERABLE; b.
Performance of a CHANNEL CALIBRATION on the PORV actuation channel at least once per 18 months; and Verifying the PORV block valve is open at least once per 72 hours8.333333e-4 days <br />0.02 hours <br />1.190476e-4 weeks <br />2.7396e-5 months <br /> c.
when the PORV is being used for overpressure protection.
o " 4.4.9.3gThe RCS vent (s) shall be verified to be open at least once per v"
12 hours1.388889e-4 days <br />0.00333 hours <br />1.984127e-5 weeks <br />4.566e-6 months <br /> when the vent (s) is being used for overpressure protection.
4.4.9.3.3 The positive displacement pump shall be demonstrated inoperabl at least once per 31 days, except when the reactor vessel head is removed g
or when both centrifugal charging pumps are inoperable and secured, by v-verifying that the motor circuit breakers are secured in the open position.***'
Icsnar 3 r-Iusur '+
+
I. cars Seectricarrant NOTA 7 ions A
dxcept when the vent pathway is provided with a valve which is locked, sealed,
. or otherwise secured in the open position, then verify these valves open at east once per 31 days.
, he provisions of 3.0.4 and 4.0.4 are not applicable for entry into MODE 4 from MODE 3 for the positive displacement pump declared inoperable pursuant 3#. g 4
to Specification 4.4.9.3.3 provided that the positive displacement pump is t
3
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declared dNOPERAB W within 4 hours4.62963e-5 days <br />0.00111 hours <br />6.613757e-6 weeks <br />1.522e-6 months <br /> after entry into MODE 4 from MODE 3 or ca prior to the temperature of one or more of the RCS cold legs decreasing g elow 325'F, whichever comes first.
hschre e.h;-p;sitive di:ph:::;nt ;;;; ::::y b; :n:rgized-fee-test 4ng previded-the
- 3 7;; 37 ;3
- p. 7?has been isolated from the RCS by a closed isolation valve with power removed from the valve operator, or by a manual isolation valvesecuredintheclosedposition.i ruse i -
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SOUTH TEXAS - UNITS 1 & 2 3/4 4-38 Unit 1 - Amendment No. 4 i
NOC-AE-000521 Page t of 4 ATTACHMENT 5 TECHNICAL SPECIFICATION BASES MARKED-UP PAGES ETI lon62311
NOC-AE-000521 j
i A/
//
Anachmem 5
/Vo L#ANGE.S h//s PME Page 2 of 4 P.EACTOR COOLANT SYSTEM BASES l
PRESSURE / TEMPERATURE LIMITS (Continued) increase with increasing heatup rate, a lower bound curve cannot be defined.
Rather, each heatup rate of interest must be analyzed on an individual basis.
Following the generation of pressure-temperature curves for both the steady-state and finite heatup rate situations, the final limit curves are produced as follows. A composite curve is~~ constructed ba'ed on'a' point-by-s point comparison of the steady-state and finite heatup rate data? At'any given temperature, the allowable pressure is taken.to be the lesser of the three values taken from the curves under consideration. >:
The use of the composite curve is necessary to set conservative heatup limitations because it is possible for conditions to exist such that over the course of the heatup ramp.the contro111n.g. condition s. witches from the inside.
to the outside a'nd the pr, essure limit must at all times be based on analysis of the most critical criterion.
L.
Finally, the composite curves. for the heatup-rate : data' and the cooldown rate data are adjusted for possible errors in the pressure and temperature sensing instruments by the values indicated on the respective curves.
Although the pressurizer operates in temperature ranges above those for which there is reason for concern of nonductile failure, operating limits are provided to assure compatibility of operation with the fatigue analysis performed in accordance with the ASME Code requirements.
LOW TEMPERATURE OVERPRESSURE PROTECTION The OPERABILITY of two PORVs or an RCS vent opening of at least 2.0 square inches ensu'res that the RCS will be protected from pressure transients which could exceed the limits of Appendix G to 10 CFR Part 50 when one or more of the RCS cold legs are less than or equal to 350*F. Either PORV has adequate relieving capability to protect the RCS from overpressurization when the transient is limited to either:
(1) the start of an idle RCP with the secondary water temperature of the steam generator less than or equal to 50*F above the RCS cold leg temperatures, or (2) the maximum credible mass injection flow rate due to the startup of a single HHSI pump plus 100 gpm net charging flow, while the RCS is in a water solid condition and the RCS temperature is between 350*F and 200*F.
For RCS temperatures less than 200*F, the maximum overpressure event consists of operating a centrifugal charging pump with complete termination of j
letdown and a failure of the charging flow control valve to the full flow l
condition.
SOUTH TEXAS - UNITS 1 & 2 B 3/4 4-14 Unit 1 - Amendment No. -4, 62 Unit 2 - Amendment No. 51 L
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NOC-AE-000521 l
Anachment 5 i
kd [HANGES
/4/:5 bGE Page 3 0f 4 REACTOR COOLANT SYSTEM BASES LOW TEMPERATURE OVERPRESSURE PROTECTION (Continued)
The design mass input transient in MODE 4 assumes that, with failure of one PORV to open, a safety injection signal will start one High Head Safety Injection pump. The normal charging and letdown flow paths would be isolated by a containment isolation phase "A" signal, but a Reactor Coolant Pump seal flow rate of 100 gpm would be maintained (normal seal flow is 20 gpm). The i
capacity of each PORV is sufficient to discharge the combined High Head Safety Injection and Reactor Coolant Pump seal flow rate at RCS pressure below the present maximum allowable PORV setpoint pressure for 200*F.
In MODE 5, the mass input transient assumes the operation of one Centrifugal Charging Pump (CCP) with letdown isolated and the charging flow control valve full open.
In each case the letdown is isolated allowing only the path through the RCP seals l
with a maximum CCP flow of 100 gpm. Whether one or both CCPs are lined up to the RCP seal flow path, the credible flow through the RCP seals can only be 20 gpm with letdown isolated unless a seal failure occurs. Therefore, by positioning the charging isolation valve closed during a pump testing or switching process, assurance is provided that a mass additional pressure
- transient, which exceeds the relief capacity of a single PORV, will not occur.
'The Maximum Allowed PORV Setpoint for the Cold Overpressure Mitigation i
System (COMS) is derived by analysis which models the performance of the COMS assuming various mass input and heat input transients. Operation with a PORV Setpoint less than or equal to the maximum Setpoint ensures that Appendix G criteria will not be violated with consideration for a maximum pressure i
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SOUTH TEXAS - UNITS 1 & 2 B 3/4 4-14a Unit 1 - Amendment No. 62 Unit 2 - Amendment No. 51 l
l NOC-AE-000521 REACTOR COOLANT SYSTEM Page 4 of 4 BASES i
LOW TEMPERATURE OVERPRESSURE PROTECTION (Continued) overshoot beyond the PORV Setpoint which can occur as a result of time delays in signals processing and valve opening, instrument uncertainties, and single l
failure. To ensure that mass and heat input transients more severe than those assumed cannot occur. Technical Specifications require lockout of all high head safety injection )umas while in MODE 5 and MODE 6 with the reactor vessel head on. All but one 1191 head safety injection pump are required to be locked out in MODE 4.
Technical Specifications also require lockout of the positive dis)lacement pump and all but one charging pump while in MODES 4, 5, and 6 with tie reactor vessel head installed and disallow start of an RCP if secondary temperature is more than 50'F above primary temperature.3 Iuscar10 Administrative controls and two RHR relief valves will be used to provide cold overpressure protection (COMS) during the ASME stroke testing of two administratively declared inoperable PORVs. During the performance of the PORV function test, two RHR trains will be OPERABLE and in operation with the auto closure interlock bypasses (or deleted) to provide COMS.
With one PORV inoperable COMS will be provided during the ASME test by the OPERABLE PORV and one RHR relief valve associated with an OPERABLE and operating RHR train which has the auto closure interlock bypassed (or deleted), Each RHR relief valve provides sufficient capacity to relieve the flow resulting from the maximum charging flow with concurrent loss of letdown.
. Analysis conservatively demonstrates that the RHR relief valves limit RCS pressure'to approximately 590 psig.
Therefore two OPERABLE and operating RHR trains.qC one OPERABLE PORV and one OPERABLE and operating RHR train will provide adequate and redundant
. overpressure protection. Use of the RHR relief valves will maintain the RCS pressure below the low temperature limits of ASME Section III, Appendix G.
l With regard to the MODE 6 a)plicability of this Technical Specification, I
the statement "with the head on tie reactor vessel" means any time the head is installed with or without tensioning the RPV studs.
)
The Maximum Allowed PORV Setpoint for the COMS will be updated based on the results of examinations of reactor vessel matrr1al irradiation
- surveillance specimens performed as required by 10 CFR Part 50, Appendix H.
3/4.4.10 STRUCTURAL INTEGRITY - BASES The inservice inspection and testing programs for ASME Code Class 1, 2.
and 3 components ensure that the structural integrity and operational readiness of these components will be maintained at an acceptable level SOUTH TEXAS - UNITS 1 & 2 B 3/4 4-15 Unit 1 - Amendment No. 4. 36. 55 1119-97 Unit 2 - Amendment No. G7. 44 1119-97 L
NOC-AE-000521 Page 1 of 5 ATTACHMENT 6 TECHNICAL SPECIFICATION RECONSTITUTED PAGES
[ Note: These pages represent the Technical Specification with amendments incorporated, and are provided for the reviewer's convenience.]
TscJts_Rev1 NOC-AE400521, FINAL doc STI. 30862331
REACTOR COOLANT SYSTEM OVERPRESSURE PROTECTION SYSTEMS LIMITING CONDITION FOR OPERATION 3.4.9.3 An Overpressure Protection System shall be OPERABLE with a maximum of one centrifugal charging pump capable of injecting into the RCS and the emergency core cooling system (ECCS) accumulators isolated and either a. or b. below:
a.
Two power-operated relief valves (PORVs) with lift settings which do not exceed the limit established in Figure 3.4-4, or b.
The Reactor Coolant System (RCS) depressurized with an RCS vent of greater than or equal to 2.0 square inches.
APPLICABILITY: MODES 4 and 5, and MODE 6 when the head is on the reactor l
vessel.
ACTION:
- a. With one or more ECCS accumulators not isolated, isolate the ECCS accumulator (s) within 1 hour1.157407e-5 days <br />2.777778e-4 hours <br />1.653439e-6 weeks <br />3.805e-7 months <br />.
- b. With more than one centrifugal charging pump capable of injecting into the RCS, immediately initiate action to render all but one centrifugal charging pump incapable of injecting into the RCS,
2
- c. With one PORV inoperable in MODE 4, restore the inoperable PORV to OPERABLE status within ? days or depressurize and vent the RCS through at least a 2.0 square inch vent within the next 8 hours9.259259e-5 days <br />0.00222 hours <br />1.322751e-5 weeks <br />3.044e-6 months <br />.
- d. With one PORV inoperable in MODES 5 or 6 with the head on the reactor vessel, restore the inoperable PORV to OPERABLE status within 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br />, or complete depressurization and venting of the RCS through at least a 2.0 square inch vent within the next 8 3
hours.
- e. With both PORVs inoperable, depressurize and vent the RCS through at least a 2.0 square inch vent within 8 hours9.259259e-5 days <br />0.00222 hours <br />1.322751e-5 weeks <br />3.044e-6 months <br />.
3
- f. In the event either the PORVs or the RCS vent (s) are used to mitigate an RCS pressure transient, a Special Report shall be prepared and submitted to the Commission pursuant to Specification 6.9.2 within 30 days.
The report shall describe the circumstances initiating the transient, the effect of the PORVs or RCS vent (s) on the transient, and any corrective action necessary to prevent recurrence.
- g. The provisions of Specification 3.0.4 are not applicable.
SOUTH TEXAS - UNITS 1 & 2 3/4 4-36 Unit 1 - Amendment No.
Unit 2 - Amendment No.
L
t MAXIMUM ALLOWABLE PORV SETPOINT THE 2 PUMP AND 4 PUMP CURVES COINCIDE AT GREATER THAN 200 DEG F 750
,_2 6
hw*
7M J
6 E
OA
-j p 650
<E 30 3 A E$
x# 600 E ct:
JO
<A E
550 z
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............ b.
Q-500 0
50 100 150 200 250 300 350 400 T
- AUCTIONEERED LOW MEASURED RCS TEMPERATURE (DEG F)
..... 5 4 PUW OPERATION 2 PUW OPERATlONl J
FIGURE 3.4-4 NOMINAL MAXIMUM ALLOWABLE PORV SETPOINT FOR THE COLD OVERPRESSURE SYSTEM SOUTH TEXAS - UNITS 1 & 2 3/4 4-37 Unit 1 - Amendment No.
Unit 2 - Amendment No.
, OVERPRESSURE PROTECTION SYSTEMS SURVEILLANCE REQUIREMENTS 4.4.9.3.1 Each PORV shall be demonstrated OPERABLE by:
a.
PerformanceLof an ANALOG CHANNEL OPERATIONAL TEST on the PORV actuation channel, but excluding valve operation, within 31 days prior to entering a condition in which the PORV is required OPERABLE and at least once per 31 days thereafter when
. the PORV is required OPERABLE;
- b. Performance of a CHANNEL CALIBRATION on the PORV actuation channel at.least once per 18 months; and
- c. Verifying the PORV block valve is open at least once per 72 hours8.333333e-4 days <br />0.02 hours <br />1.190476e-4 weeks <br />2.7396e-5 months <br /> when the PORV is being used for overpressure protection.
4.4.9.3.2 The RCS vent (s) shall be verified to be open at least once per 12 hours1.388889e-4 days <br />0.00333 hours <br />1.984127e-5 weeks <br />4.566e-6 months <br />' when the vent (s) is being used-for overpressure protection.
4.4.9.3.3'.The positive displacement pump shall be demonstrated inoperable 5 at.least once per 31 days, except when the reactor vessel head is removed or when both centrifugal charging pumps are inoperable and secured, by verifying that the motor circuit breakers are secured in the open position.2 4.4.9.3.4 Verify at least once every 31 days that only one centrifugal 2
charging pump is capable of injecting into the RCS, except when the reactor vessel head is removed, by verifying that the motor circuit breakers are secured in the open position.2 4.4.9.3.5 Verify at least once every 12 hours1.388889e-4 days <br />0.00333 hours <br />1.984127e-5 weeks <br />4.566e-6 months <br /> that each ECCS accumulator is isolated.
SPECIFICATION NOTATIONS
{
2 ECCS accumulator isolation is required only when ECCS accumulator pressure is greater than or equal to the maximum RCS pressure for the existing RCS cold leg temperature allowed by Figures 3.4-2 and 3.4-3.
2 L
An inoperable centrifugal charging pump (s) and/or positive displacement charging pump may be energized for testing or pump switching provided the discharge of the pump (s) has been isolated from the RCS by a closed isolation valve with power removed from the valve operator, or by a manual isolation valve secured in the closed position. Reactor coolant pump seal l
injection flow may be maintained during the RCS isolation process.
3 This ACTION may be suspended for up to 7 days to allow functional testing to
- verify PORV operability.
During this test period, operation of systems or components which could result in an RCS mass or temperature increase will be Jadministratively controlled. During the ASME stroke testing of two inoperable PORVS, cold overpressurization mitigation will be provided by two RHR discharge relief valves associated with two OPERABLE and operating RHR loops which have the auto closure interlock bypassed [or deleted).
If one PORV is inoperable, cold overpressure mitigation will be provided by the OPERABLE PORV and one RHR discharge relief valve associated with an OPERABLE and operating RHR loop which has the auto closure interlock bypassed [or deleted).
- Except when the vent pathway is provided with a valve that is locked, sealed, or otherwise secured in the open position, then verify these valves open at least once per 31 days.
f SOUTH TEXAS'-' UNITS 1 & 2 3/4 4-38 Unit 1 - Amendment No.
~
Unit 2 - Amendment No.
O
5 The provisions of 3.0.4 and 4.0.4 are not applicable for entry into MODE 4 fr'om MODE 3 while making all but one centrifugal charging pump incapable of injecting into the RCS pursuant to Specification 4.4.9.3.4, and for the positive displacement pump declared inoperable pursuant to Specification 4.4.9.3.3 provided that all but one centrifugal charging pump is made incapable of injecting into the RCS, and the positive displacement pump is declared inoperable within 4 hours4.62963e-5 days <br />0.00111 hours <br />6.613757e-6 weeks <br />1.522e-6 months <br /> after entry into MODE 4 from MODE 3 or prior to the temperature of one or more of the RCS cold legs decreasing below 325'F, whichever comes first.
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i SOUTH TEXAS - UNITS 1 & 2 3/4 4-38a Unit 1 - Amendment No.
Unit 2 - Amendment No.