ML19345F375
| ML19345F375 | |
| Person / Time | |
|---|---|
| Site: | Rancho Seco |
| Issue date: | 02/02/1981 |
| From: | SACRAMENTO MUNICIPAL UTILITY DISTRICT |
| To: | |
| Shared Package | |
| ML19345F370 | List: |
| References | |
| TAC-10968, NUDOCS 8102170358 | |
| Download: ML19345F375 (9) | |
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RANCHO SECO UNIT 1 TECHNICAL SPECIFICATIONS Surveillance Standards 4.6 EMERGENCY POWER SYSTEM PERIODIC TESTING Applicabliity Applies to the periodic testing and surveillance of the emergency power system.
Objective To verify that the emergency power sources and equipment are operable and respond properly when required.
Specification 4.6.1 At intervals not to exceed one month, a test of the diesel generators will be performed to verify proper operation of these emergency power sources and associated equir-;..c.
This test will be performed to assure that:
A.
Each diesel generator can be started from the control room.
B.
Each diesel generator can be synchronized with its associated 4160 voit nuclear service bus.
4.6.2 During each refueling interval, a test of the diesel generators and emerger y start circuits shall be performed to verify that these-emergency power sources and associated equipment are operable by:
A.
Simulating a loss of offsite power in, conjunction with a safety features actuation signal, and:
1)
Verifying de-energization of the nuclear services buses and operation of the load shedding circuitry.
2)
Verifying the diesel starts from ambient condition on the' 51 auto-start signal and. energizes the nuclear services buses, and by verifying proper operation of the automatic load sequencing circuitry. The diesel generators will be operated for at least 5 minutes in this condition.
I 3)
Verifying that on diesel-generator trip, the load sheddino circuitry operates properly and the diesel restarts on the auto-start signal, and by verifying proper operation of the automatic load sequencing circuitry. The diesel generator.
will be operated for at least 5 minutes in this condition.
B.
Load. testing the diesel generators to SFAS' capacity.
l h-34
. Proposed Amendment No.'51 Rev'.1
@l02170%E 2
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RANCHO SECO UNIT 1 TECHNICAL SPECIFICATIONS Surveillance Standards 4.6.3 Each diesel generator shall be given a thorough inspection at least biannual?* following the manufacturer's recommendations for this class of standby service.
4.6.4 Batteries in the 125 volt DC systems shall be tested as follows:
A.
The voltage and specific gravity of each pilot cell shall be measured and recorded weekly.
B.
The specific gravity., level and voltage of each c.cIl shall be measured and recorded every month.
C.
Each time data are recorded, new data shall be compared with old to detect signs of deterioration.
D.
During each refueling interval, the battery shall be subjected to a rated load or equivalent test. The battery voltage as a func-tion of time shall be monitored to establish that the battery performs as expected.
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4-34a Proposed Amendment No. 51 Rev..I
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a TABLE 4.1-1 (Continued)
INSTRUMENT SURVEILLANCE REQUIREMENTS Channel Description Check Test Calibrate Remarks 42.
Reactor Building drain accumulation tank level NA NA R
43 Incore neutron detectors M(1)
NA NA (1) Check Functioning, including functioning of computer readout and/or recorder readout y
E 44.
Process and area radiation
@ g monitoring systems W
M Q
RM P8 45 Emergency plant radiation m
y, 7
instruments M(1)
NA R
(1) Battery check AE Y
D 46.
Environmental air monitors M(1)
NA R
(1) Check functioning 2 E.
9Z 47 Strong motion accelerometer Q(1)
NA R
(1) Battery check d _,
E E
{
48.
Voitage protection S(1)
(1) Compare voltmeter readings a.
R E'
Y 51s' S
b.
Overvoltage M
R I
c.
Time delay M
R
=
c>
2 E
S = Each shift M = Monthly P = Prior to each startup if not done previous week Q
D = Daily Q = Quarterly R = Once during the refueling interval C
a
- o E
W = Weekly
RANCHO SECO UntT 1 TECHNICAL SPECIFICATIONS Limiting Conditions for Operation 3.7 AUXILIARY ELECTRICAL SYSTEMS Applicability Applies to the availability of off-site and on-site electrical power for station operation and for operation of station auxiliaries.
Object ive To define those conditions of electrical power availability necessary to provide for safe reactor operation and to provide for continuing availability of engineered safety features in an unrestricted manner.
Specification 3.7.1 The reactor shall not be brought critical unless the following conditions are met:
A.
All nuclear service buses, nuclear service switchgear, and nuclear service load shedding systems are cperable.
B.
Two 220 KV lines are in service.
C.
One 6900 volt reactor coolant pump motors bus is energized.
D.
Emergency diesel generators are operable and at least 35,000 gallons of fuel are in each storage tank.
E.
Plant batteries are charged and in service.
f F.
Two out of three bat tery changers are operable for ~125 vol t DC l
buses "A" and "C", and "B" and "D".
i G.
Three out of four inverters are-operable for 120 volt AC vital bus power.
H.
Both startup transformers,.No. 1.and No. 2, are in s'rvice.
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l.
The-swi tchyard vol tage is 218' KV or-above.
[_51
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j 3 7.2 The reactor shall not remain critical unless all of the following requirements are satisfied:
A.
One 220 KV.line shall be fully operational and capable ~of f
carrying nuclear service and auxiliary power'except as specified in D below.
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3 -
Proposed Amendment No. 51'Rev. I
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RANCHO SECO UNIT 1 TECHNICAL SPECIFICATIONS Limiting. Conditions for Operation B.
Both startup transformers shall be in service except that one will be sufficient if during the time one startup transformer is inoperable, a diesel generator is started and run continously.
C.
Both diesel generators shall be operable except that from and,after the date that one of the diesel generators is made or fotnd to be inoperable for any reason, reactor operation is permissible for the succeeding 15 days provided that during such 15 days the oper-able diesci generator shall be load tested daily and both startup transformers are available.
If the diesel is not returned to service at the end of 15 days, the other diesel will be started and run with at least mirimum load continuously for an additional 15 days.
If at the end of the second 15 days the diesel is not returned to service, the reactor shall be ibrought to the cold shut-down condition within an additional 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br />.
I D.
If the plant isseparatedfromthesystem)whilecarryingitsown auxiliaries, or if all 220 KV lines are lost, continued reactor -
operation is permissible provided that one emergency diesei genera-
. tor shall be started and run continuously until a transmission line is restored.
E.
The essential nuclear service electrical buses, switchgear,, load shedding, and automatic diesel start systems shall be operable except as provided in C above and as required for surveillance testing.
F.
Nuclear service batteries are charged and in service except that one nuclear service battery may be removed from service.for not more than 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br />.
G.
Both nuclear service buses are operable except that one nuclear service bus may be removed f rom service-for not more than 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br /> provided that all equipment on the other ' nuclear service bus is operable.
H.
If the switchyard voltage is below 2'18 KV.for less than 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br />, no corrective action is required. After.24_ hours, if-the voltage has not increased above.218 KV, both diesel generators will b 51 started, connected to the nuclear service buses, and the.startup transformers removed from the nuclear service buses.
Switchyard voltage above 218 KV will allow unrestricted plant operation.
3.7 3 If both diesel _ generators become inoperable, the unit shall be placed in the cold shutdown contition.
3.7.4 The voltage protection system trip setting'shall be as stated in' Table 51 3.7.1.
3,
Proposed Amendment No. 51, Rev.:1-l
RANCHO SECO UNIT 1 TECHNICAL SPECIFICATIONS Limiting Conditions for Operation 3.7.5 Voltage Protection System Limiting Conditions A.
Startup and operation are not permitted unless the minimum require-ments and action statements of Table 3.7.2 are met.
51 B.
In the event the number of protective channels falls below that listed in Table 3.7.2, the plant will be brought to a hot shutdown within 48 hours5.555556e-4 days <br />0.0133 hours <br />7.936508e-5 weeks <br />1.8264e-5 months <br />.
Bases The auxiliary electrical power systems are arranged so that no single failure can inactivate enough safety features equipment to jeopardize plant sa fe ty.
The normal source of power to the redundant nuclear service-loads is by the two startup transformers connected to. the 220-KV station switchyard. All of the normal power supply to plant auxiliary loads is provided through the two unit auxiliary transformers connected to the generator bus.
Emergency power for the nuclear service loads is obtained from two on-site diesel generators.
Since the startup transformers are sized to carry full plant auxiliary loads, if plant auxiliaries' power is not available from the unit auxiliary trans-former it will be obtained from the startup transformers.
The five 220-KV transmission lines are not.under the direct control of the Rancho Seco station. Therefore, all five cannot be assumed to be available at all times.
However, extensive reliability and protective features are utilized so that the probability of losing more than one source of 220-KV power from faults is low.
By requiring that two 220-KV lines are in service prior to startup', one circuit will be immediately available following~a loss of the onsite alternating current diesel power supplies and the other offsite 220-KV l.
line.
If there is a loss of all 220-KV remote connections, power to the-safety features will be supplied'by the diesel generators.
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The 35,000 gallons of fuel stored in each storage tank permit operation of the two diesel generators for seven days.
It is considered unlikely not to j
be able to. secure fuel oil from an outside source during'this-time under the-j.
worst of weather conditions.
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The four 125 volt DC control panelboards are arranged so that loss of one bus will not preclude safe shutdown or operation of safety features systems.
During' periods when one plant battery is de-energized for. test or maintenance, the associated.125 Volt DC bus can be supplied from its battery-charger.
Each redundant pai r ("A and "C", "B" and "D") of' safe'ty features ac tuat ion i
and reactor protection 125 volt'DC buses has a' standby battery. charger--in addition to the two bus battery chargers.. Loss of power f rom one battery
)
. charger per pair of redundant DC buses has no significant consequence since a standby battery charger is available.
In addition, each 125 volt.DC bus
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can cont inue to receive power f rom its. respective battery without interruption.
i 3-43 Proposed Amendment No. SbRev. 1
RANCHO SECO UNIT 1 TECHNICAL SPECIFICATIONS Limiting Conditions for Operation Sufficient redundancy is available with any three of the four 120 volt AC vital power buses in service that reactor safety is assured.
Every reasonable effort will be made to maintain all safety instrumentation in operation.
During periods of station operation under the condition of electrical system degradation, as described above in Specification 3.7.2, the operating action required is to start and run sufficient standby power supplies so as not to compromise the safety of the plant.
As seen in Specification 3.7.2, a time limit is placed on operation during certain degraded conditions based on the reliability of the available power supply.
The voltage protection system is designed to isolate the nuclear survice buses from the startup transformers when the bus voltage exceeds the allowable operating limits of the equipment. The allowable operating range for the 4160 volt nuclear service buses is 3731 to 4626 volt's and 397 to 521 volts 51 for the 480 volt nuclear service buses. This corres' ponds to a switchyard voltage range of 214 to 244 KV.
This range of switchyard voltage encompasses the normal operating range of 221 to 239 KV.
n 3-44 Proposed Amendment No. 51."ev. I
TABLE 3.7.1 VOLTAGE PROTECTION SYSTEM RELAY TRIP VALUES Trip Value Time Delay Undervoltage (Note 1) a.
Dropout 3771 + 38V 12s + 1.2s E
b.
75 percent of 4160V 3120 + 31V 1.9 + 0.2s gg 51
-- =
n n c.
Complete loss 0
1.5 + 0.2s pg vi vi sf Overvoltage 4580 + 46V 3.0 + 0.3s ag n o
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o Note.1 - The ' relay voltage' values. shown have been converted by the PT ratio (40:1) for review g --
- f convenience.
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t TABLE 3.7.2 Minimum Total Number Channels Channels Action Functional Unit of Channels to Trip OPERABLE (Note 1)
Undervoltage 3/ Bus 2/ Bus 2
A w
Overvoltage 3/ Bus 2/ Bus 2
A p;
E 5' R E Action Statements w
I-Action A - With the number of OPERABLE channels one less than the total Number of Channels 51
?? 8 E
operation may proceed provided both of the following conditions are satisfied:
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a.
The inoperable channel is placed in the tripped condition within one hour.
[,
E b.
The Minimum Channels OPERABLE requirement is met; however, one additional U!
{
channel may be bypassed for up to 2 hours2.314815e-5 days <br />5.555556e-4 hours <br />3.306878e-6 weeks <br />7.61e-7 months <br /> for surveil lance test ing.
g Note 1: The above table is not applicable when the plant is in cold shutdown.
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