ML17311B030

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Proposed Tech Specs Re Temp Method to Respond to Sustained Degraded Switchyard Voltage
ML17311B030
Person / Time
Site: Palo Verde  Arizona Public Service icon.png
Issue date: 07/03/1995
From:
ARIZONA PUBLIC SERVICE CO. (FORMERLY ARIZONA NUCLEAR
To:
Shared Package
ML17311B029 List:
References
NUDOCS 9507140191
Download: ML17311B030 (12)
v • d • e


Text

ELECTRICAL POWER SYSTEMS LIMITINGCONDITION FOR OPERATION (CONTINUED)

ACTION (Continued) f.* With switchyard voltage less than 524 kV and with three startup transformers in service, restore OPERABILITY of one train of A.C.

sources by blocking fast bus transfer within 1 hour1.157407e-5 days <br />2.777778e-4 hours <br />1.653439e-6 weeks <br />3.805e-7 months <br />; AND" either:

Restore OPERABILITY of the remaining EDG by starting, loading, and separating from offsite power within the next hour; the remaining offsite circuit to OPERABLE status within AND'estore 72 hours8.333333e-4 days <br />0.02 hours <br />1.190476e-4 weeks <br />2.7396e-5 months <br /> AND within 6 days from the discovery of failure to meet the LCO; OR Restore OPERABILITY of the remaining train of A.C. sources by blocking fast bus transfer within the next hour; OR

3. 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 in COLD SHUTDOWN within the following 30 hours3.472222e-4 days <br />0.00833 hours <br />4.960317e-5 weeks <br />1.1415e-5 months <br />.

g.* With switchyard voltage less than 525 kV and with two startup transformers in service, restore OPERABILITY of one train of A.C.

sources by blocking fast bus transfer within 1 hour1.157407e-5 days <br />2.777778e-4 hours <br />1.653439e-6 weeks <br />3.805e-7 months <br />; AND'ither:

Restore OPERABILITY of the remaining EDG by starting, loading, and separating from offsite power within the next hour; the remaining offsite circuit to OPERABLE status within AND'estore 72 hours8.333333e-4 days <br />0.02 hours <br />1.190476e-4 weeks <br />2.7396e-5 months <br /> AND 6 within days from the discovery of failure to meet the LCO; OR Restore OPERABILITY of the remaining train of A.C. sources by blocking fast bus transfer within the next hour; OR

3. 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 in COLD, SHUTDOWN within the following 30 hours3.472222e-4 days <br />0.00833 hours <br />4.960317e-5 weeks <br />1.1415e-5 months <br />.

This amendment will expire upon full compliance with GDC 17.

Enter appiicabie conditions and requirements of TS LCD 3 8 3 1 ACTION a and ACTION b for the INOPERABLE train. In addition, with no A.C. power source to one train, enter appiicabIe conditions and ACTIONs of TS LCO 3.8.1.1, "Onsite Power Distribution Systems -Operating."

Enter applicabie conditions and requirements of TS LCO 3.8.1.1 ACTION a for the INOPERABLE offsite circuit.

PALO VERDE - UNIT 1 3/0 8-2A AMENDMENT 9'507140191 950703 PDR ADOCK 05000528 P PDR

ELECTRICAL POWER SYSTEMS

'LIMITINGCONDITION FOR OPERATION (CONTINUED)

ACTION (Continued) f." With switchyard voltage less than 518 kV and with three startup transformers in service, restore OPERABILITY of one train of A.C.

sources by blocking fast bus transfer within 1 hour1.157407e-5 days <br />2.777778e-4 hours <br />1.653439e-6 weeks <br />3.805e-7 months <br />; AND'ither:

Restore OPERABILITY'ofthe remaining EDG by starting, loading, and separating from offsite power within the next hour; the remaining offsite circuit to OPERABLE status within AND'estore 72 hours8.333333e-4 days <br />0.02 hours <br />1.190476e-4 weeks <br />2.7396e-5 months <br /> AND within 6 days from the discovery of failure to meet the LCO; OR Restore OPERABILITY. of the remaining train of A.C. sources by blocking fast bus transfer within the next hour; 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 in COLD SHUTDOWN within the following 30 hours3.472222e-4 days <br />0.00833 hours <br />4.960317e-5 weeks <br />1.1415e-5 months <br />.

g.* With switchyard voltage less than 525 kV and with two startup transformers in service, restore OPERABILITY of one train of A.C.

sources by blocking fast bus transfer within 1 hour1.157407e-5 days <br />2.777778e-4 hours <br />1.653439e-6 weeks <br />3.805e-7 months <br />; AND'ither:

Restore OPERABILITY of the remaining EDG by starting, loading, and separating from offsite power within the next hour; the remaining offsite circuit to OPERABLE status within AND'estore 72 hours8.333333e-4 days <br />0.02 hours <br />1.190476e-4 weeks <br />2.7396e-5 months <br /> AND within 6 days from the discovery of failure to meet-the LCO; OR Restore OPERABILITY of the remaining train of A.C. sources by blocking fast bus transfer within the next, hour; OR

3. 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 in COLD SHUTDOWN within the following 30 hours3.472222e-4 days <br />0.00833 hours <br />4.960317e-5 weeks <br />1.1415e-5 months <br />.

This amendment will expire upon full compliance with GDC 17.

Enter applicableconditionsand requirements of TS LCD 3 8 3.1 ACTION a and ACTIONb for the INOPERABLE train. In addition.

with no A.C. power source to one train, enter applicable conditions and ACTIONs of TS LCO 3.8.1.1 "Onsite Power Distribution

~

Systems - Operating.

Enter applicable conditions and requirements of TS LCO 3.8.1.1 ACTION a for the INOPERABLE offsite circuit.

PALO VERDE - UNIT 2 3/4 8-2A AMENDMENT

ELECTRICAL POWER SYSTEMS LIMITINGCONDITION FOR OPERATION (CONTINUED)

ACTION (Continued) f.* With switchyard voltage less than 518 kV and with three startup transformers in service, restore OPERABILITY of one train of A.C.

sources by blocking fast bus transfer within 1 hour1.157407e-5 days <br />2.777778e-4 hours <br />1.653439e-6 weeks <br />3.805e-7 months <br />; AND'ither Restore OPERABILITY of the remaining EDG by starting, loading, and separating from offsite power within the next hour; the remaining offsite circuit to OPERABLE status within AND'restore 72 hours8.333333e-4 days <br />0.02 hours <br />1.190476e-4 weeks <br />2.7396e-5 months <br /> AND within 6 days from the discovery of failure to meet the LCO; OR Restore OPERABILITY of the remaining train of A.C. sources by blocking fast bus transfer within the next hour; 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 in COLD SHUTDOWN within the following 30 hours3.472222e-4 days <br />0.00833 hours <br />4.960317e-5 weeks <br />1.1415e-5 months <br />.

C g.* With switchyard voltage less than 525 kV and with two startup transformers in service, restore OPERABILITY of one train of A.C.

sources by blocking fast bus transfer within 1 hour1.157407e-5 days <br />2.777778e-4 hours <br />1.653439e-6 weeks <br />3.805e-7 months <br />; AND'ither:

Restore OPERABILITY of the remaining EDG by st'arting, loading, and separating from offsite power within the next hour; the remaining offsite circuit to OPERABLE status within AND'estore 72 hours8.333333e-4 days <br />0.02 hours <br />1.190476e-4 weeks <br />2.7396e-5 months <br /> AND within 6 days from the discovery of failure to meet the LCO; OR Restore OPERABILITY of the remaining train of A.C. sources by blocking fast bus transfer within the next hour; 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 in COLD SHUTDOWN within the following 30 hours3.472222e-4 days <br />0.00833 hours <br />4.960317e-5 weeks <br />1.1415e-5 months <br />.

This amendment will expire upon full compliance with GDC 17.

Enter applicable conditions and requirements of TS LCO 3 8 3.1 ACTION a and ACTION b for the INOPERABLE train. In addition, with no A.C. power source to one train, enter applicable conditions and ACTIONs of TS LCO 3.8.1.1, "Onsite Power Distribution Systems - Operating." C Enter applicable conditions and requirements of TS LCO 3.8.1.1 ACTION a for the INOPERABLE offsite circuit.

PALO VERDE - UNIT 3 3/4 8-2A AMENDMENT

ELECTRICAL POWER SYSTEMS BASES A.C. SOURCES D. C. SOURCES AND ONSITE DISTRIBUTION SYSTEMS (Continued)

ACTION requirements 3.8.1.1.f and 3.8.1.1.g provide restrictions upon continued unit operation commensurate with degradation of switchyard voltage and restoration of OPERABILITY of the required A.C. sources. Conformance to GDC-17 requires maintenance of switchyard voltages at or above those identified in ACTIONs 3.8.1.1.f and 3.8.1.1.g. At voltages below those identified, a unit trip resulting from a SIAS, coincident with low switchyard voltages, will result in sequencing of ESF equipment on preferred offsite power. The Class 1E degraded'voltage relays will detect a sustained degraded voltage due to the fast bus transfer on non-Class 1E loads from the auxiliary transformer to the startup transformers. The relays will actuate to strip the ESF equipment and resequence it on the emergency diesel generator. This "double sequencing" causes an interruption in equipment credited with specific response time in UFSAR Chapter 6 and Chapter 15 safety analysis, and is unanalyzed. Maintenance of switchyard voltage at or above the specified value prevents this effect. The required voltage is higher when three units are operating on two startup transformers, as two secondary.windings of the startup transformers must each supply ESF power to two units.

PALO VERDE - UNIT 1 B 3/4 8-2A AMENDMENT

r,~

F

ELECTRICAL POWER SYSTEMS

'BASES A.C. SOURCES D. C. SOURCES AND ONSITE DISTRIBUTION SYSTEMS (Continued)

ACTION requirements 3.8.1.1.f and 3.8.1.1.g provide restrictions upon continued unit operation commensurate with degradation of switchyard voltage and restoration of OPERABILITY of the required A.C. sources. Conformance to GDC-17 requires maintenance of switchyard voltages at or above those identified in ACTIONs 3.8.1.1.f and 3.8.1.1.g. At voltages below those identified, a unit trip resulting from a SIAS, coincident with low switchyard voltages, will result in sequencing of ESF equipment on preferred offsite power. The Class,1E degraded voltage relays will detect a sustained degraded voltage due to the fast bus transfer on non-Class 1E loads from the auxiliary transformer to the startup transformers. The relays will actuate to strip the ESF equipment and resequence it on the emergency diesel generator. This "double sequencing" causes an interruption in equipment credited with specific response time in UFSAR Chapter 6 and Chapter 15 safety analysis, and is unanalyzed. Maintenance of switchyard voltage at or above the specified values prevent this effect. The requiied voltage is higher when three units are operating on two startup transformers, as two secondary windings of the startup transformers must each supply ESF power to two units.

PALO VERDE - UNIT 2 B 3/4 8-2A AMENDMENT

1 r

PLEC7 RICAL POWER SYSTEMS BASES A.C. SOURCES D. C. SOURCES AND ONSITE DISTRIBUTION SYSTEMS (Continued)

ACTION requirements 3.8.1.1.f and 3.8.1.1.g provide restrictions upon continued unit operation commensurate with degradation of switchyard voltage and restoration of OPERABILITY of the required A.C. sources. Conformance to GDC-17 requires maintenance of switchyard voltages at or above those identified in ACTIONs 3.8.1.1.f

~

and 3.8.1.1.g. At voltages below those identified, a unit trip resulting from a SIAS, coincident with low switchyard voltages, will result in sequencing of ESF equipment on preferred offsite power. The Class 1E degraded voltage relays will detect a sustained degraded voltage due to'the fast bus transfer on non-Class 1E loads from the auxiliary transformer to the startup transformers: The relays will actuate to strip the ESF equipment and resequence it on the emergency, diesel generator. This "double sequencing" causes an interruption in equipment credited with specific response time in UFSAR Chapter 6 and Chapter 15 safety analysis, and is unanalyzed. Maintenance of switchyard voltage at or above the specified values prevent this effect. The required voltage is higher when three units are operating on two startup transformers, as two secondary windings of the startup transformers must each supply ESF power to two units.

PALO VERDE - UNIT 3 B 3/4 8-2A AMENDMENT

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