ML20031H077
| ML20031H077 | |
| Person / Time | |
|---|---|
| Site: | Haddam Neck File:Connecticut Yankee Atomic Power Co icon.png |
| Issue date: | 09/30/1981 |
| From: | CONNECTICUT YANKEE ATOMIC POWER CO. |
| To: | |
| Shared Package | |
| ML20031H068 | List: |
| References | |
| NUDOCS 8110270114 | |
| Download: ML20031H077 (21) | |
Text
i.
Docket No. 50-213 Attachment IIaddam Neck Plant Proposed Revisions to Technical Specifications September, 1981 l
0110270114 811021 PDR ADOCK 05000213 p
3.9 OPERATIONAL SAFETX INSTRUMENTATION AND CONTROL SYSTEMS Applicability: Applies to the operability of plant instrumen-tation and control systems required for reactor safety.
Objective:
To specify the limits imposed on plant operation by those instrumentation and control systems re-quired for reactor safety.
Specification: This specification relates to the items listed in Table 3.9-1.
The use of the table is 111ust-rated in the basis.
Table 3 9-LA is a continuation of Table 3.9-1 in Standard Technical Specification format.
A.
Plant operation at a rated power shall be permitted to continue with the logic stated in column I of Table 3.9-1, for on-line testing or in the event a subsystem in-strumentation channel fails.
B.
In the event the number of channels of a particular subsystem in service falls below the limit given in Table 3.9-1, column I, so that the required logic cannot be met, plant operation shall be limited according to the requirement shown on Table 3.9-1, column II.
C.
Neutron monitoring instrumentation shall be provioed to continuously monitor neutron flux intensities from the fully shutdown condition to 120% of full power. Neutron monitors in each range shall be in continuous operation until at least one decade of reliable in-dication is verified on the next range of instrumentation.
D.
With an undervoltage channel inoperable, take the action shown in Table 3.9-1A.
1 Basis:
In column I of Table 3.9-1, the first figure is the number of operational channels which must sense the abnormal condition in order to in;tiate a protective ection. The second figure is the uinimum number of operational ch?nnels required for the reactor to be at full power. As an example, consider the nuclear overpower reactor trip.
Two channels must sense a nuclear power equal to or greater than the overpower trip setting for a reactor trip to occur. A minimum of three channels must be operable and in service to sense nuclear overpower for the reactor to be at full power.
3-14 t
I Re' actor safety, consistent with reliability of operation, is provided by the reactor protection system, which automatically initiates approp-riate action to prevent exceeding established limits. This specification outlines limiting conditions for operation necessary to preserve the effectiveness of the reactor control and protection system when any one of the channels is out of service.
The term " operator surveillance" used in Table 3.9-1 means that, when prescribed, an operator shall continuously be watching the specified instruments.
REFERENCE:
(1) FDSA Section 7.2 3-15
TABLE 3.9-1 MINIMUM INSTRUMENTATION OPERATING-CONDITIONS Functional Unit Column I Column II Logic Required for Required Operating Action if At Power Requirements Full Power Operation Column I Logic Cannot be Met 1.
Nuclear Overpower Reactor Trip 2/3 Maintain Shutdown Conditions 2.
Pressurizer Variable Low Pressure Reactor Trip 1/2 Maintain Load Below 10% Full Power (F.P.)
3..
Pressurizer Fixed High Pressure Reacter Trip 1/2 Maintain Shutdown Conditions u4.
Pressurizer High Water Level Reactor Trip 1/2 Maintain Load Below 10% F.P.
5.
Low Coolant Flow Reactor Trip-4 Loop Operation 1/4 Maintain Load Below 84% F.P.
-3 Loop Operation 1/3 Maintain Load Below 10% F.P.
6.
Pressurizer Low. Pressure Signal (For Safety Injection Trip) 1/2 Maintain Shutdown Conditions l
7.
Deleted 8.
M:nual Trip 1/1 Maintain Hot Shutdown Conditions 9.
Steam-Feedwater Flow Mismatch Coincident Continuous Operator Surveillance of with Low Steam Generator Level-Reactor Trip 1/4 Steam and Feedwater Flow Recorder and Steam Generator Vater Level of Affected Steam Generator
- 10. High Steam Flow Isolation valve Trip-4 Loop Operation 2/4 Isolate Corresponding Loop
-3 Loop operation 2/3 Maintain Shutdown with 1/2 Startup Requirement Intermediate Range SUR Reactor Trip 1/1 Maintain Shutdown Conditions Source Range SUR Rod Stop 1/1 Maintain Shutdown Conditions Refueling Pequirement Shutdown High Neutron Level Alarm 1/1 No Changes in Care Geometry Pe mitted 3-15a
I TABLE 3.9-1A ENGINEERED SAFETY FEATURE ACTUATION SYSTEM INSTRINENTATION MINIMLH FUNCTIONAL UNIT TOTAL NO.
CllANNELS CilANNFLS ADPLICABLE FICTION OF CilANNELS TO TRIP OPERABLE MODES 11.
LOSS OF POWER a.
4.16 Kv Emergency Bus Undervoltage (3/ Bus)
(2/ Bus)
(2/ Bus) 1,2,3,4 1
Level 1 (Loss of Voltage) b.
4.16 Kv Emergency Bus Undervoltage (3/ Bus)
(2/ Bus)
(2/ Bus) 1,2,3,4 1
Level 2 (Degraded Voltage) c.
4.16 Kv Emergency Bus Undervoltage (3/ Ben)
(2/ Bus)
(2/ Bus) 1,2,3,4 1
Level 3 (Degraded voltage)
ACTION 1 - With the number of OPERABLE Channels one less than the Total Number of Channels, STARTUP and/or POWER OPERATION may proceed provided the following conditions are satisfied:
a.
The inoperable channel is placed in the tripped condition within I hour.
b.
The Minimum Channels OPERABLE requirements is met; however, one additional 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 /> during surveillance 'esting as required in Table 4.2-1A 3-15b
3.12 STATION SERVICE P.OWER APPLICABILITY Applies to the availability ef station service power to operate plant auxiliaries.
OBJECTIVE:
To specify those conditions of electrical pcwer availability neccasary to insure safe reactor operation ar.d the performance of engineered safeguards.
SPECIFICATIONS:
A)
When the plant is in Modes 1, 2, 3, or 4, the following conditions must be met; 1)
Two physically independent circuits between the effsite transmission network and the onsite safety related distribution system must be operable.
2)
Two diesel generators must be opersble.
3) a.
With an offsite circuit or diesel generator inoperable, verify the operability of the re-maining A.C. sources within 1 hour1.157407e-5 days <br />2.777778e-4 hours <br />1.653439e-6 weeks <br />3.805e-7 months <br /> and once per 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br /> thereafter; restore the inoperable circuit or diesel generator to operable status within 72 hours8.333333e-4 days <br />0.02 hours <br />1.190476e-4 weeks <br />2.7396e-5 months <br /> or be in COLD SHUTDOWN within the next 36 hours4.166667e-4 days <br />0.01 hours <br />5.952381e-5 weeks <br />1.3698e-5 months <br />, b.
With both an offsite circuit and a diesel gen-erator inoperable or with both offsite A.C.
circuits inoperable, verify the operability of the remaining A.C. sources within one hour and once per 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br /> thereafter; restore at least one of the inoperable sources to operable status within 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br /> er be in COLD SHUTDOWN within the next 36 hours4.166667e-4 days <br />0.01 hours <br />5.952381e-5 weeks <br />1.3698e-5 months <br />. Restore both A.C. circuits and both diesel generators to operable status within 72 hours8.333333e-4 days <br />0.02 hours <br />1.190476e-4 weeks <br />2.7396e-5 months <br /> of the initial loss or be in COLD SHUTDOWN within the next 36 hours4.166667e-4 days <br />0.01 hours <br />5.952381e-5 weeks <br />1.3698e-5 months <br />.
c.
With both diesel generators inoperable, verify the operability of the two offsite A.C. circuits within 1 hour1.157407e-5 days <br />2.777778e-4 hours <br />1.653439e-6 weeks <br />3.805e-7 months <br /> and at least once per 24 houra thereafter; restore at least one of the diesel generators to opersble status within 2 hours2.314815e-5 days <br />5.555556e-4 hours <br />3.306878e-6 weeks <br />7.61e-7 months <br /> or be in COLD SHUTDOWM within the next 36 hours4.166667e-4 days <br />0.01 hours <br />5.952381e-5 weeks <br />1.3698e-5 months <br />.
Restore both diesel generators to operable status within 72 hours8.333333e-4 days <br />0.02 hours <br />1.190476e-4 weeks <br />2.7396e-5 months <br /> of the initial loss or be in COLD SHUTDOWN within the next 36 hours4.166667e-4 days <br />0.01 hours <br />5.952381e-5 weeks <br />1.3698e-5 months <br />, 3-21 e
~
f 4)
Both of.the two 4160 - volt.cmergency buses, each i ~
.of the four 480 - volt buses and each of the four 120 - volt vital buses shall be operable and ener-j '
gfzed. With any of these A.C. buses inoperable, restore that bus to operable ~ status within 72 hours8.333333e-4 days <br />0.02 hours <br />1.190476e-4 weeks <br />2.7396e-5 months <br /> or bc in COLD SHUTDOWN within the next 36 hours4.166667e-4 days <br />0.01 hours <br />5.952381e-5 weeks <br />1.3698e-5 months <br />.
(With either Emergency Bus #8 or #9 or 480 volt buses
- 4 and #5 or #6 and #7 incapable of being powered by a diesel generator, restoreithe capability to supply emergency power-to that_ bus within 72 hours8.333333e-4 days <br />0.02 hours <br />1.190476e-4 weeks <br />2.7396e-5 months <br /> or be in COLD SHUTDOWN within the next 36 hours4.166667e-4 days <br />0.01 hours <br />5.952381e-5 weeks <br />1.3698e-5 months <br />.)
5)
Each of-the two 125 - volt D.C. buses, 125 - volt battery bank and battery chargers must be operable.
With any of these components inoperable, restore that l
component to operable status within 72 hours8.333333e-4 days <br />0.02 hours <br />1.190476e-4 weeks <br />2.7396e-5 months <br /> or be in COLD SHUTDOWN within the next 36 hours4.166667e-4 days <br />0.01 hours <br />5.952381e-5 weeks <br />1.3698e-5 months <br />.
B)
The loading of euch diesel generator shall not exceed 2850 kw.
C)
When the plant is in modes 1 or 2, the following con-ditions must be met:
1)
With the voltage on an inservice 4.16 KV emergency bus below the level three undervoltage setpoint (3940V), but above 3620 volts, restore that bus to the level three setpoint voltage or higher t
within 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br /> or be in HOT STANDBY within the next 6 hours6.944444e-5 days <br />0.00167 hours <br />9.920635e-6 weeks <br />2.283e-6 months <br />.
2)
With the voltage on an inservice 4.16 KV emer-gency bus below the level two undervoltage set-point (3620V), the reactor shall be in HOT STANDBY within the next 4 hours4.62963e-5 days <br />0.00111 hours <br />6.613757e-6 weeks <br />1.522e-6 months <br />.
'l-Basis:
The electrical system equipment is arranged so that no single contingency can inactivate enough safe-guards equipment to jeopardize the plant safety.
The 480-volt equipment is arranged on 4 buses. The 4160-volt equipment is supplied from 6 buses, two-
'of which are emergency busec. This' arrangement is shown in Figure 9.1-1, 2, 3 and 9.5-1 of the FDSA.
Two separate outside sources supply station service power to the plant thrcugh the two 115/4.16 KV station service transformers. 'The separation.of the.
j!-
two sources is maintained in the 4160-volt, 480-volt and lower voltage systems.
4 1
3-21a-a
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The plant, auxiliary equipment is arranged electrically so that m.1tiple items receive their power from the two diffe.ent sources. One charging pump and two s afety it.Jection pumps are supplied from each 4160-volt emerg?ncy bus. A service water pump and a containment recirculation fan are supplied from each 480-volt bus.
The but of the valve motor control center, MCC5 is taking its feed from either of two separate sources.
One outside source of power is capable of supplying sufficient power to run normal operating equipment.
One 115/4.16 KV station service transformer is capable of supplying all the auxiliary loads exclusive of the reactor coolant pumps.
The bus arrangements specified for operation ensure that power is available to an adequate number of safe-guards cuxiliaries, With additional switching, more equipn.ent could be out of service without infringing on safety. however, as stated, the specification should not limit operation unduly and is more clear cut for easy administration.
Each diesel has capacity enough to start and run a fully loaded high pressure safety injection pump, a fully loaded low pressure cafety injection pump, a service water pump, a containment fan, valves, etc.
The diesel generator also has capacity enough to start and run a residual heat removal pump in combination with any one of the first two pumps, a service water pump, a containment fan, valves, etc.
These com-binations of pumps, etc., can adequately cool the core for any loss of coolant incident and maintain the con-tainment pressure within the design value.
One battery charger shall be in service so that the batteries will always be at full charge in anticipation of a loss of ac power incident.
This ensures that adequate DC power will be available for starting the emergency generators and other emergency uses.
The loading of each diesel generator is limited to 2850 KW.
As a result of this limit, there is a 100 KW margin with respect to the seven day per year rating; and 200 KW margin with respect to the thirty minute overload rating.
3-22
In orde'r to assure that safeguards loads can perform 1
their design functions, the voltage at their term-inals must be within acceptable tolerances. The voltage drop due to starting safeguards motors from the offsite power source, while all the auxiliary _
loads associated with normal full load output are assumed te remain connected, is found to be the limit-ing case. To assure the voltage will not drop below the acceptable tolerance of the most limiting equip-nent when the safeguards loads are required to start with the plant operating at full load, the voltage at the 4.16 KV emergency bus must be equal to or greater tnan 3940 volts prior to a S.I. signal.
This voltage will be detected by the level-three undervoltage bistables connected to the potential transformers for the safeguards buses. The bi-stables and all other equipment used in the scheme are Class 1E.
Should the voltage fall below the level-three setpoint followed by a safety injection signal, the offsite power source will be auto-matically tripped and the onsite power supplies started to insure proper voltage levels. Recog-7 nizing the low likelihood of a LOCA, it is reascnable to allow continued full power operation with volcage conditions below the level-three setpoint, but no safety injection signal, for a period of 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br /> so long as the voltage does not fall to the level of 3620 volts where equipments would be operating at voltages below acceptable levels. This 24 hour2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br /> period allows time for corrective measures te be taken-to raise the voltage.
The level-three scheme assures that adequate voltage is present prior to starting the safeguards loads.
Ilowever, starting of safeguards loads will most pro-bably result in a running voltage below the level-three setpoint but above the minimum acceptable voltage (3620 volts). To prevent'the level-three undervoltage scheme from interrupting the sequencing of safeguards loads, the level-three scheme will be blocked once the safeguards loads begin to sequence.
The operator will receive an alarm if the voltage drops below the level-three setpoint.
3-22a
. ~ - -.. -
The level-two scheme ~ operates when the'4.16 KV 'ous voltage drops to the 3620-volt level and will be in service at all times.
If the level two scheme operates, the operator will receive an alarm.
If, at any time,.the level-two scheme operates and is coincident with a safety injection signal, the offsite power source will be automatically tripped and the onsite power supplies' started to insure, proper voltage levels.
During normal plant operations, all Jarge motors, except dedicated safeguards loads, are normally running. Any remaining small loads which might oc started would produce a negligible voltage drop during starting or running. Under these normal plant operating conditions, voltages as low as 3620 volts can be sustained continuously on the 4.16 KV emergency buses without subjecting loads on the 4160-volt or 480-volt electrical systems to valtages outside of their talerances.
If the voltage should drop below 3620 volts, equipments would be subjected to voltages outside of their ratings. This then is the basis for proceeding to
.he hot standby mode should the voltage fall-below the 3620-volt level.
References:
(1) FDSA Section 9.3 (2) FDSA Section 9.4 (3)
D. C. Switzer (CYAPCO) letter to D. L. Ziemann (NRC) dated May 22, 1978 (4)
D. C. Switzer (CYt_PCO) letter to D. L. Ziemann (NRC) dated May 24, 1978 L
s 3-22b i
4.2 OPERATIONAL SAFETY ITEMS Applicability:
Applies to items directly related to safety limits and limiting conditions for operation.
Objective:
A.
Instrumentation shall be checked,' tested, and calibrated at sufficiently frequent intervals to assure safe operation.
B.
Equipment and sampling test shall be conducted at sufficiently frequent intervals to assure safe operation.
Specification:
Calibration testing, and checking shall be,"
performed as detailed in Tables 4.2-1, 4.2-1A, and 4.2-2.
Undervoltage setpoints are specified in Table 4.2-3.
Basis:
Nuclear flux channels shall be calibrated every day when the plant is at power using a heat balance calculation to account for discrepancies resulting from changes in the control rod pattern and core physics parameters.
Process system channels for parameters such as pressure, flow, level, and temperature may be subject to small long-time drift j
errors. Available statistics based on Yankee-Rowe nuclear plant experience have l
shown that the drift of trip setpoints between refuelings is not excessive and has generally averaged less than 2% with a maximum 3.5%.
Control channel total channel i
drift has averaged less than 3% with a esximum drift of 4.5%. _Between refuelings, a regular check by the operators of similar instruments in separate channels will point up an inconsistent channel in time to test and repair that channel's components before they jeopardize plant operations, c
Operator checks will also reveal blown fuses, l
opened circuits or improperly functioning electronic components.
In general, conditions such as these will be annunciated at the main control board and therefore can be immediately noted for testing.
i l
a 4-2 L,
~.
Periodic testing of instrumentation channels when no deficiency is apparent is not considered desirable. The risk of inadvertently tripping the plant is increased whenever a channel is being tested. The risk that a channel will be left inoperative after a test, while small, is nevertheless also increased.
Furthe more, while the channel is on test, it is..ot available to perform its design function, be it control or protection.
Experience with process instrumentation in industry, thermal plants and at the Yankee-Rowe power reactor supports these statements.
Testing of all three levels of undervoltage protection is required to assure that the circuits will perform their design functions at the appropriate trip values. The loss-of-voltage (level one) protective circuitry is designed to trip the circuit breakers to the offsite power supply, start the onsite power supply, and other functions within one second upon the complete loss of-offsite power.
This brief time delay is to allow for transmission network fault clearing. The level two voltage protective circuitry will also trip the offsite power scurce if ther, is a safety injection signal present and the voltage is_below the level-two setpoint'(as opecified in Table 4.2-3).
The level-two logic incorporates a nine second time delay.
The level three protective circuitry will. trip the offsite power supply if a safety injection signal occurs provided the low voltage condition exists prior to -
the SI signal.
This trip.would also include a nine second time delay.
Reference:
(1) FDSA - Section 7 4-2.1
TABLE 4.2-1A i
ENGINEERED SAFETY FEATURE ACTUATION SYSTEM INSTROMENTATION SURVEILLANCE REOUIRDfENTS 1
CHANNEL CilANNEL CilANNEL MODES IN WilICll l
FUNCTIONAL UNIT CllECK CALIBRATION FUNCTIONAL SURVEILLANCE REQUIRED TEST
' 25.
LOSS-OF POWER
.a.
4.16 Kv Emergency Bus Undervoltage S
R M
1, 2, 3, 4 Level 1 (Loss of Voltage) b.
4.16 Kv Emergency Bus Undervoltage S
R M
1, 2, 3, 4 Level 2 (Degraded Voltage) c.
4.16 KV Emergency Bus Undervoltage S
R M
1,2,3,4 Level 3 (Degraded Voltage)
- g!
4 e
i 4
6 x
...m TABLE 4.2-3 UNDERVOLTAGE PROTECTION SYSTEMS CALIBRATION SETPOINTS I
Functional Unit-Trip Setpoint Allowable Values i
8 - LOSS OF POWER a.
.4.16 KV Emergency Bus 2870 volts
- 2870 + 86 volts
- undervoltage (loss of voltage)
Level l' b.
'4.16 KV Emergency. Bus 3620 volts 3620 1 20 volts undervoltage (degraded voltage) 9 seconds 8-10 seconds Level 2
. time delay time delay 4
c.
4.16 KV Emergency Bus 3940 volts 3940 1 20 volts undervoltage (degraded voltage) 9 seconds 8-10 seconds
-h Level 3 time delay time delay c.
- Setpcint'ia by tap position. Time delay of device.is inverse. function of voltage. Device must change state within 0.95-1.05 seconds when the input voltage to the device goes from normal to zero volts instantaneously.
F March 21, 1981 4.3 CORE COOLING SYSTEMS - PERIODIC TESTING Applicabilitu: Applies to periodic testing requirements for the core cooling system.
' objective:
To verify the operability of the core cooling systems.
Specifica tion : A) During each refueling shutdown, a test shall be conducted to demonstrate proper automatic operation of the core cooling systems.
The test shall be performed in accordance with written procedure cs summarized below:
1)
The two independent core cooling egstems will be tested separately. A test signal will be applied to initiate a loss of normal AC power to each of the emergency power systems while a coincident signal is applied which initiates operation of the emergency core cooling equipment associated with the system being tested.
2)
Verification shall be made that the diesel gen-erator and its associated pumps have started in the proper r equence and that the high pressure safety injection and low pressure safety injection (core deluge) attain required discharge heads of 1400 psig and 295 psig^respectively. Following this check of the automatic sequence, one of the safety injection pumps will be secured and the associated charging pump will be started manually. Verifica tion shall be made that the charging pump attains the required discharge head of 2150 psig. ' The next step s
will be to secure either the charging pump or the remaining safety injection pump and manually start the associated RHR pump.
Verification will be made that the RHR pump attains the required discharge head of 145 psig.
3)
The test will be considered satisfactory if-control board indication and visual observations indicate all ~ components have operated and sequenced properly.
- 4) A prerequisite for this test shall be that either:
a) the RCS shall be vented by a 3" or larger opening and the RCS OPS shall be inservice, or b) a minimum of two' three inch openings shall be used for venting if both trains of the RCS OPS -
are out of service.
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4.- Th2 prsssura drop ceross occh chere231 filter bank chall be determined pariedically.
5.
The syste= dampers shall be tested periodically to verify operability and proper orientation.
B.
Acceptance Criteria 1.
Values of the efficiencies measured during the test of IV.A.1 shall be at least 95%.
l 2.
Values of the efficiencies measured during the test of IV.A.2 shall be at least 99%.
[
C.
Corrective Action 1.
The activated charcoal or the complete charcoal filter unit shall be replaced if the acceptance criterion of IV.B.1 is not met.
2.
Leakage paths through each filter bank will be located and repaired if the acceptance criterion of IV.B.2 is not met.
3.
Unusual conditions which could affect the intended application of the charcoal filter shall be corrected.
D.
Test Frequency 1.
The iodine removal efficiency tests shall be performed
(
on the same test frequency as the integrated leakage rate tests, as tabulated in Section 1-D hereof.
2.
Visual inspection of the filter installation and pres-sure drop determinations shall be perfo m ed at least monthly.
3.
The damper operation and positioning tests shall be performed monthly.
E.
Report of Test Results Each integrated leakage rate test will be the subject of a summary technical report and will include summaries of Specification II, III, and IV test results ired.
Basis:
A leakage value of,0.3% per 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br /> will under the most adverse accident conditions maintain public exposure well below 10 CTR 100 values in the event of the hypothetical accident (see Section 10.4 of the FDSA). De maximum allowable leakage rate Lp, has been reduced to 0.25% per 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br /> to reflect the less severe, air only, test conditions.
The tests at the design pressure of 40 psi will assure the continued ability of the containment to perform its function.
(
nis test plus the original test at 15 psi and the continuous tests at 1-2 psig will establish the relationship between leakage rates and containment pressure to be used in the
, extrapolation of low pressure measurem-nts to the accident pressure.
4-9 t
4.5 EMERGENCY POWER SYSTEM PERIODIC TESTING Applicabilitv: Applies to periodic testing requirements of the 4
emergency power system.
Objective:
To verify that the emergency power system will respond promptly and properly when required.
Specification:
A.
Each diesel generator shall be demonstrated OPERABLE monthly by:
1.
Verifying the fuel volume in the day and engine-mounted fuel tank to be at least 400 gallons.
2.
Verifying the fuel volume in the fuel storage tank to be at least 3250 gallons.
3.
Verifying the fuel transfer pump can be started and transfers fuel from the storage system to the day and engine-mounted tank.
4.
Verifying the diesel starts from ambient condition and accelerates to at least 450 rpm in less than or equal to 8 seconds.
5.
Verifying the generator is synchronized, manually loaded to between 2750 kw and 2850 kw, and operates for greater than or equal to two (2) hours.
6.
Ver.ifying the diesel generator is aligned to provide standby power to the associated emergency busses.
7.
Verifying that the automatic load sequence timers are OPERABLE with the following allowable elapsed times:
EQUIPMENT ALLOWABLE ELAPSED TIME LPSI Pump
< 3 sec.
HPSI Pump jL10 sec.
Charging Pump ji 20 sec.
Service Water Pump 33 1 5 sec.
Backup Service Water Pump 38 1 5 sec.
Containment Recire. Fan 43 1 5 sec.
Backup Containment Recire. Fan 48 1 5 sec.
NOTE:
Failure of any of the above items will require retest of that item in accordance with the frequency specified in Table 4.5-1.
B.
During each refueling, each dimel generator shall be demonstrated s
operable, one safeguards train at a time, by simulating a loss of offsite power coincident with a safety injection signal and verifying that:
4-11
1.
The emergency buses are de-energized and load shedding occurs.
2.
The diesel starts from ambient conditions on the auto start signal, energizes the emergency buses with permanently connected loads, energizes the auto connected emergency loads through-the load sequence timers and operates for more than five minutes while its generator is loaded with the emergency loads.
3.
That upon interruption of the diesel generator power source, the loads are shed from the emergency buses, the diesel start relay is re-energized with the auto start signal, the emergency buses are energized with-permanently connected loads, the auto connected emergency loads are energized through the load sequence timers and the diesel operates for more than five minutes while its generator is loaded with the emergency loads.
C.
Each of the' required independent circuits between the offsite transmission network and the onsite safety related distribution system shall be:
1.
Determined OPERABLE at least once per seven days by verifying correct breaker alignments, indicated power availability, and 2.
Demonstrated OPERABLE at least once per 18 months during shutdown by transferring (manually and automatically) unit power supply from the normal circuit to the alternate circuit.
D.
The AC buses specified in Section 3.12 shall be determined OPERABLE at least once per seven days by verifying correct breaker alignment and indicated power availability.
E.
Each DC bus train specified in Section 3.12 shall be determined OPERABLE ar* energized at least once per seven 4
days by verifying correct breaker alignment and indicated power availability.
F.
Each 125 - volt battery bank and charger shall be demonstrated OPERABLE:
4-12
1.
At least once per seven days by verifying that:
a.
The electrolyte level of each pilot cell is between the minimum and maximum level indication marks, b.
The pilot cell specific gravity, corrected to 770F and full electrolyte level, is greater than or equal to 1.200.
The pilot cell voltage is greater than or equal c.
to 2.1 volts, and, d.
The overall battery voltage is greater than or equal to 125 volts.
2.
At least once per 92 days by verifying that:
a.
The voltage of each connected cell is greater than or equal to 2.1 volts under float charge.
b.
The specific gravity, corrected to 77 F and full electrolyte level, of each connected cell is greater than or equal to 1.190.
c.
The electrolyte level of each connected cell is between the minimum and maximum level indication marks.
E l
J 4-13
'N TABLE 4.5-1 DIESEL GENERATOR TEST SCHEDULE Number of Failures in Last 100 Valid Tests
- Test Frequency
<1 At least once per 31 days 2
At least once per 14 days
>f 3 Ai least once per 7 days
- Criteria for deterniaing number of failures and number of valid tests shall be in accordance with Regulatory Position C.2.e of Regulatory Guide 1.108, Revision 1, August 1977, where the-last 100 tests are determined on a per nuclear unit basis.
For the purposes of this test schedule, only valid tests conducted af ter the OL issuance date shall be included in the computation of the "last 100 valid tests."
Entry into-
'this test schedule shall be made at the 31 day frequency.
I w
4 d
4 l~
.4-14 a.
P g-
. v Basis:
The design cc the emergency power system features complete separation or the emergency buses, their respective power supplies and associated relaying, thus, providing a means of testing the controls and equip.mni associated with an individual emergency bus without t: quiring a complete interruption of outside power to the site.
Loss of voltage on the normal supply to either emergency bus will initiate automatic operation which isolates that particular bus from its normal supply, strips all loads from that particular 4160v bus and its associated 480v buses, starts the respective diesel generator, connects it to the emergency ous and sequentially starts the train of associated safeguards equipment.
The tests specified above demonstrate that the diesel generators will provide power for operation of vital equipment. They also assure that the emergency generator system controls will function automatically in the event of either a partial or complete loss of normal ac station service power.
The testing frequency specified is sufficient to identify and correct any mechanical or electrical deficiency before it can result in a system failure. The control components are in dust-tight enclosures and not subject to drif t.
The fuel supply, starting circuits, and controls are continuously monitored. An abnormal condition in these systems would be signaled without having to place the diesel generators themselves on test.
The nartial loss of AC test, as described, removes the undesirable aspect of completely separating the site from outside power sources unnecessarily.
REFERENCE:
FDSA Section 9.5 t
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