ML20247K208
| ML20247K208 | |
| Person / Time | |
|---|---|
| Site: | Summer  |
| Issue date: | 07/21/1989 |
| From: | SOUTH CAROLINA ELECTRIC & GAS CO. |
| To: | |
| Shared Package | |
| ML20247K205 | List: |
| References | |
| NUDOCS 8907310481 | |
| Download: ML20247K208 (5) | |
Text
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3/4.8 ELECTRICAL POWER SYSTEMS 3/4.8.1 A.C. SOURCES OPERATING LIMITING CONDITION FOR OPERATION 3.8.1.1 As a minimum, the following A.C. electrical power sources shall be OPERABLE:
Two physically independent circuits between the offsite transmission a.
network and the onsite Class 1E distribution system, and Two separate and independent Emergency Diesel Generators (EDG), each b.
with:
A separate day fuel tank containing a minimum volume of 300 1.
gallohs of fuel, 2.
A separate fuel storage system containing a minimum volume of 42,500 gallons of fuel, and gg
'3.
A separate fuel transfer pump.
APPLICABILITY:
MODES 1, 2, 3 and 4.
ACTION:
With one offsite circuit of 3.8.1.1.a inoperable:
a.
1.
Demonstrate the OPERABIt'ITY of the remaining offsite A.C.
sources by performing Surveillance Requirement 4.8.1.1.1.a 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 8 hours9.259259e-5 days <br />0.00222 hours <br />1.322751e-5 weeks <br />3.044e-6 months <br /> thereafter, and 2.
If either EDG has not been successfully tested within the past f
24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br />, demonstrate its OPERABILITY by performing Surveillance Requirement 4.8.1.1.2.a.3 separately for each such EDG within 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br /> unless the diesel is already operating, and 3.
Restore the offsite circuit 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 at least 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 /> and 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 />.
b.
With ore EDG of 3.8.1.1.b inoperable:
1.
Demonstrate the OPERABILITY of the A.C. offsite sources by performing Surveillance Requirement 4.8.1.1.1.a within I hour and at least once per 8 hours9.259259e-5 days <br />0.00222 hours <br />1.322751e-5 weeks <br />3.044e-6 months <br /> thereafter, and 2.
If the EDG became inoperable due to any cause other than preplanned preventive maintenance or testing, demonstrate the OPERABILITY of the remaining EDG by performing Surveillance.
Requirements 4.8. 1.1.2.a.3 within 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br /> *, and
- This test is required to be completed regardless of when the inoperable EDG l
is restored to OPERABILITY.
SUMMER - UNIT 1 3/4 8-1 AMENDMENT NO.77 l
i 890721 89073104s1 gDR ADOCK0500gG
1 ELECTRICAL POWER SYSTEMS A.C. SOURCES SHUTDOWN LIMITING CONDITION FOR OPERATION
- 3. 8.1. 2 As a minimum, the following A.C. electrical power sources shall be OPERABLE:
One circuit between the offsite transmission network and the onsite a.
Class IE distribution system, and b.
One diesel generator
- with:
1.
A day fuel tank containing a minimum volume of 300 gallons of
- fuel, 2.
A fuel storage system containing a minimum volume of 30,000 gallons of fuel, and 33 gy 3.
A fuel transfer pump.
APPLICABILITY:
MODES 5 and 6.
ACTION:
With less than the above minimum required A.C. electrical power sources OPERABLE, immediately suspend all operations involving CORE ALTERATIONS positive reactivity changes, movement of irradiated fuel, or crane operation with loads over the l
fuel storage pool.
In addition, when in MODE 5 with the Reactor Coolant loops not filled, or in MODE 6 with the water level less than 23 feet above the reactor vessel flange, immediately initiate corrective action to restore the required sources to OPERABLE status as soon as possible.
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l SURVEILLANCE REQUIREMENTS l
- 4. 8.1. 2 The above required A.C. electrical power sources shall be demonstrated OPERABLE by the performance of each of the Surveillance Requirements of 4.8.1.1.1, j
4.8.1.1.2 (with the exception of 4.8.1.1.2.a.4) and 4.8.1.1.3.
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- ESF load sequencer may be deenergized in Modes 5 and 6 provided that the loss
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of voltage and degraded voltage relays are disabled.
SUKMER - UNIT 1 3/4 6-8 AMENDMENT NO. 77 I
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3/4.8 ELECTRICAL POWER SYSTEMS BASES 3/4.8.1, 3/4.8.2 AND 3/4.8.3 A.C. SOURCES, D.C. SOURCES AND ONSITE POWER DISTRIBUTION SYSTEMS The OPERABILITY of the A.C. and 0.C power sources and associated distribution systems during operation ensures that sufficient power will be available to supply the safety related equipment required for 1) the safe shutdown of the facility and 2) the mitigation and control of accident condi-tions within the facility.
The minimum specified independent and redundant A.C. and D.C. power sources and distribution systems satisfy the requirements of General Design Criterion 17 of Appendix "A" to 10 CFR 50.
The ACTION requirements specified for the levels of degradation of the power sources provide restriction upon continued facility operation commensurate with the level of degradation.
The OPERABILITY of the power sources are consistent with the initial condition assumptions of the safety analyses and are based upon maintaining at least one redundant set of onsite A.C. and D.C.
power sources and associated distribution systems OPERABLE during. accident conditions coincident with an assumed loss of offsite power and single failure l
of the other onsite A.C. source.
The A.C. and D.C. source allowable out-of-service times are based on Regulatory Guide 1.93, " Availability of Electrical l
Power Sources," December 1974.
When one diesel generator is inoperable, there is an additional ACTION requirement to verify that all required systems, subsystems, trains, components and devices, that depehd on the remaining OPERABLE diesel generator as a source of emergency power, are also OPERABLE, and that the steam-driven auxiliary feedwater pump is OPERABLE.
This require-ment is intended to provide assurance that a loss of offsite power event will not result in a complete loss of safety function of critical systems during the period one of the diesel generators is inoperable.
The' term verify as used in this context means to administratively check by examining logs or i
other information to determine if certain components.are out-of service for i
maintenance or other reasons.
It does not mean to perform the surveillance requirements needed to demonstrate the OPERABILITY of the component.
The OPERABILITY of the minimum specified A.C. and D.C. power sources and associated distribution system: during shutdown and refueling ensures that
- 1) the facility can be maintained in the shutdown or refueling condition for extended time periods and 2) sufficient instrumentation and control capability is available for monitoring and maintaining the unit status.
The Surveillance Requirements for demonstrating the OPERABILITY of the diesel generators are in accordance with the recommendations of Regulatory Guides 1.9, " Selection of Diesel Generator Set Capacity for Standby Power Supplies," March 10, 1971, 1.108, " Periodic Testing of Diesel Generator Units Used as Onsite Electric Power Systems at Nuclear Power Plants," Revision 1, l
August 1977, and 1.137, " Fuel-0il Systems for Standby Diesel Generators,"
l Revision 1, October 1979, as modified by the NRC's review and approval of South I
Carolina Electric & Gas Company's June 10, 1985 and December 6, 1985 amendment requests.
Th}$ERT" l
~-5 SUMMER - UNIT 1 B 3/4 8-1 AMENDMENT 77
' Attachment 1 to Document Control Desk Letter July 21, 1989 Page 5 of 5 Insert I to Attachment 1 I
The fuel storage system minimum volume of fuel to demonstrate operability of the diesel generators was based on fuel consumption determined from time dependent loads following a design basis accident and a. loss of off-site l
power as listed in FSAR Table.8.3-3 for seven days plus a 10% fuel margin as J
recommended in Regulatory Guide 1.137. Revision 2, " Fuel-011 Systems for Standby Diesel Generators," position C.1.C(2).
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~ to Document Control Desk Letter July 21, 1989 o
Page 1 of 1 SIGNIFICANT HAZARDS EVALUATION FOR VIRGIL C. SUMMER NUCLEAR STATION A. C. Sources i
Description of amendmentrequest:
The proposed amen' ment to Sections 3.8.1.1 and 3.8.1.2'provides a more d
restrictive limiting condition for operation for the fuel oil storage requirements for the emergency diesel generators. Specifically, the design basis calculations determined that the minimum required fuel' oil storage.
volume for each diesel'should be 47,100l gallons while in Modes 1-4 and 33,200 gallons while in Modes 5 and 6. 'The current Technical Specification limits are 42,500 gallons and 30,000 gallons, respectively.
4 Basis for proposed no significant hazards consideration:
The Commission has provided standards for determining whether a no significant hazards consideration exists as stated in 10 CFR 50.92(c). A proposed amendment to an operating license involves no significant hazards consideration if operation of the facility in accordance with'the proposed-would not:
(1) involve a significant increase in the probability or consequences of an accident previously evaluated; or (2) create the possibility of a new or different kind of accident from any previously evaluated; or (3) involve a significant reduction in the margin of safety.
The Commission has provided certain examples (51 FR 7744) of actions likely to involve no significant hazards considerations. The' request involved in this case matches example (ii), a change that constitutes an additional limitation, restriction or control not presently included in the Technical Specifications.
The Licensee has determined that a no significant hazards evaluation is justified and that should this request be implemented it will not:
L Involve a significant increase in the probability or consequences of any accident previously evaluated because no plant equipment has been changed. This proposed change provides a more restrictive limiting condition for operation for the emergency diesel generators.
2.
Create the possibility.of a new or different kind of accident from any accident previously evaluated because the additional fuel oil l
requirements are necessary to ensure the. continued reliable operation of I
the emergency diesel generators.
3.
Involve a significant reduction in a margin of safety because only additional fuel oil requirements are proposed.
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