ML20093A924

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Proposed Tech Specs,Extending AOT When One Offsite Circuit Inoperable from Current 72 H to Seven Days
ML20093A924
Person / Time
Site: Millstone Dominion icon.png
Issue date: 10/06/1995
From:
NORTHEAST NUCLEAR ENERGY CO.
To:
Shared Package
ML20093A923 List:
References
NUDOCS 9510110149
Download: ML20093A924 (7)
v • d • e


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I/4.s ELECTRICAL POWDt SYSTDIS i-

! NLLI h.200RCES

! ePERATINS

. LINITING CO SITION FOR OPERATION

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! 3.8.'I.1 As a minimus, the following A.C. electrical power sources shall

be OPERA 8tE

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a. Two physically independent circuits between the offsite trans-j mission network and the switchyard, and b.- Two separate and independent diesel generators each with a separate fuel oil supply tank containing a minimum of 12,000 gallons of fuel. ,

APPLICABILITY: MODES, 1, 2, 3 and 4.

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j a. With one offsite circuit inoperable, demonstrate the OPERABILITY

of the remaining A.C. sources by performing Surveillance Requirement 4.8.1.1.1 within I hour and at least once per i 8 hours9.259259e-5 days <br />0.00222 hours <br />1.322751e-5 weeks <br />3.044e-6 months <br /> thereafter. If either diesel generator has not been ji successfully tested within the past 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br />, demonstrate its

' OPERABILITY by perfoming Surveillance Requirement 4.8.1.1.2.a.2 enerator within 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br />.

separate Restore t 1bforeachsuchdieseloffsitecircuitto0ERABLEstatuswithin72hourb i

er 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 SHUTDOW within the following 30 hours3.472222e-4 days <br />0.00833 hours <br />4.960317e-5 weeks <br />1.1415e-5 months <br />.

i b. With one diesel generator inoperable, demonstrate the OPERABILITY of the A.C. offsite sources by performing

Surveillance Requirement 4.8.1.1.1 within I hour and at least 4

once per 8 hours9.259259e-5 days <br />0.00222 hours <br />1.322751e-5 weeks <br />3.044e-6 months <br /> thereafter; and if the diesel generator became

! inoperable due to any cause other than preplanned preventative j maintenance or testing, demonstrate the OPERABILITY of the remaining OPERABLE diesel generator by performing Surveillance j Nequirement 4.8.1.1.2.a.2 within 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br /> *; restore the diesel j ponerator 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 upT STAND 8Y 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 SWTDOWN within the following 30 hours3.472222e-4 days <br />0.00833 hours <br />4.960317e-5 weeks <br />1.1415e-5 months <br />.

t in Eg.npb && For Cycle I.5 only- Restore ne elec6W cms _Ne

.g 044., g .6 OPER AB LE 5%h$ W Oi n 7 claj S or be in d'

4 , A (eas;- Hor srAND3Y Abig the WP G k wsetnciin

cout> spDoWtd 4% de. .f,{bWg so hows.
3 *This test is required to be completed regardless of when the inoperable

!i diesel generator 4s restored to n 0PERABLE status.

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N3,LLSTONE - IIIIT 2 3/48-1 Amendment No.d5, J

9510110149 951006 '

PDR ADOCK 05000336 PDR

P. -. _

May 17,1995

.' i jff.s rLtcTRIcAL povra systries l.

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The OPERA 8ILITY of the A.C. and D.C. Power sources and associated distribution systems during operation' ensures that sufficient power will

' be available to supply the safety related equipment required for 13 the the mitigation and control ed safe shutdown of tie facility accident conditions within the facil and 2)ity. The minisua specified indepen-dont and redundant A.C. and D.C. power sources and distribution systems satisfy the requirements of General Design Criteria 17 of Appendix 'A' to 10 CFR 50.

The ACTION requirements specified for the levels of degradation of I 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 -

accident analyses and are based upon maintaining at least one of each of the onsite A.C. and D.C. power sources and associated distribution systems OPERA 8LE during accident conditions coincident with an assumed loss of l

offsite power and single failure of the other onsite A.C. source.

The OPERABILITY of the minimum specified A.C.and D.'C. power sources and associated distribution systems during shutdown and refueling ensures that 1) the facility can be maintained in the shutdown or refueling sufficient instrumentation condition and control capaht11ty is available for mon itoring and maintaining the for extend 6d time periods and 2) facility sta

{'.

4 The non safety grade 125V D.C. Turbine Battery is required for accident mitigation for a main steam lir.e break within containment with a coincident loss of a vital D.C. bus. The Turbine Battery provides the alternate source of power for Inverters 1 & 2 respectively via non-safety grade Inverters 5 & 5. For the loss of a 0.C. event with a coincident steam line break within containment, the feedwater regulating valves are required to close to ensure containment design pressure is not exceeded.

The feedwater regulating valves require power to close. On loss of a vital D.C. bus, the alternate source of power to the vital A.C. bus vf a the Turbine Battery ensures power is available to the affected feedwater regulating valve such that the valve will isolate feed flow into the faulted senerator. The Turbine Battery is considered inoperable when bus voltage Is less than 125 volts D.C. thereby ensuring adequate capacity for isolation functions via the feedwater regulating valves during the onset of a steam line break.

The Turbine Battery Charger is not required to be included in Technical Specifications even though the Turbine Battery is needed to power ,

backup Inverters 5 & 6 for a main steam line break inside containment coincident with a loss of a Class 1E D.C. bus. This is due to the fact that feedwater isolation occurs within seconds from the onset of the event.

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NILLSTONE - UNIT 2 B3/44-1 Amendment No.188 em

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INSERT A A probabilistic risk assessment has examined the additional risk to pu safety, if Millstone Unit No. 2 operates in a configuration where the cross bus 14H is unavailable for a period of two weeks. The results of the assessment show that the increase in risk associated with having the cross tie unavailabl days is negligible provided that two diesel generato Millstone Unit No.1 reservo station service transformer and the 14H bus during Millstone Unit No.1 outages without requiring a shutdown of Milistone Unit No.

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  • Docket No. 50-336 B15380 i

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d Attachment 4 i

Millstone Nuclear Power Station, Unit No. 2 i

Proposed Revision to Technical Specifications Cycle-Specific A.C. Sources Allowed Outage Time Extension Retyped Version of Current Technical Specifications i

4 October 1995

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'3 3/4.8 ELECTRICAL POWER SYSTEMS l 3/4.8.1 A.C. SOURCES l

OPERATING 1

'LINITING CONDITION FOR OPERATION 3.8.1.I' As:a minimum, the following A.C. electrical power sources shall i

be OPERABLE:

a. Two physically independent circuits between the offsite trans-

. mission network and the switchyard, and ,

b .- Two separate and independent diesel generators each with a separate fuel oil supply tank containing a minimum of 12,000

gallons of fuel.

. APPLICABILITY: N0 DES, 1, 2, 3 and 4.

ACTION:

i a. With one offsite circuit inoperable, demonstrate the OPERABILITY of i the remaining A.C. sources.by performing Surveillance i Requirement 4.8.1.1.1 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. If either diesel generator has not been

successfully tested within the past 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.2 l separately for each such diesel generator within 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br />.

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 /> ** l 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 l 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 />.

' b. With one diesel generator inoperable, demonstrate the OPERABILITY of the A.C. offsite sources by performing Surveillance

. Requirement 4.8.1.1.1 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 /> i thereafter; and if the diesel generator became inoperable due to any

cause other than preplanned preventative maintenance or testing, demonstrate the OPERABILITY of the remaining OPERABLE diesel generator by performing Surveillance Requirement 4.8.1.1.2.a.2
within 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br /> *; restore the 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 at least HOT STANDBY within the next j 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 test is required to be completed regardless of when the inoperable diesel generator is restored to an CPERABLE status.
    • Except that.for Cycle 13 only - Restore the electrical cross-tie to Unit I to

. OPERABLE status within 7 days or be in at least HOT STANDBY within the next i: 6: hours 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 />.

l NILLSTONE - UNIT 2 3/4 8-1 Amendment No. f), J77. j 0221

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3/4.8 ELECTRICAL POWER SYSTEMS l

I BASES n

i The OPERABILITY of the A.C. and D.C. power sources and associated distribution systems during operation ensures that sufficient power will be available to su) ply the safety related equipment required for 1) the

safe shutdown of tie facility and 2) the mitigation and control of i accident conditions within the factitty. The minimum specified indepen-i dent and redundant A.C. and D.C. power sources and distribution systems satisfy the requirements of General Design Criteria 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 accident analyses and are based upon maintaining at least one of each of

the 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 of the other onsite A.C. source.

The OPERABILITY of the minimum specified A.C.and D.C. power sources

! and associated distribution systems during shutdown and refueling ensures j that1) 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 facility status.
A 2robabilistic risk assessment has examined the additional risk to public 1ealth and safety, if Millstone Unit No. 2 operates in a configuration where the cross-tie through bus 14H is unavailable for a i period of two weeks. The results of the assessment show that the increase
in risk associated with having the cross-tie unavailable for 14 days is

! negligible provided that two diesel generators are available. The 7 days allowed outage time provided sufficient time for maintenance to be i performed on the Unit 1 RSST and 14H bus during Millstone Unit No. 1 i outages without requiring a shutdown of Millstone Unit No. 2.

l The non-safety grade 125V D.C. Turbine Battery is required for accident mitigation for a main steam line break within containment with a coincident loss of a vital D.C. bus. The Turbine Battery provides the

alternate source of power for Inverters 1 & 2 respectively via non-safety

[ grade Inverters 5 & 6. For the loss of a D.C. event with a coincident-

steam line break within containment, the feedwater regulating valves are
required to close to ensure containment design pressure is'not exceeded.

J The'feedwater regulating valves require power to close. On loss of a vital D.C. bus, the alternate source of power to the vital A.C. bus via the Turbine Battery ensures power is available to the affected feedwater regulating valve such that the valve will isolate feed flow into the l faulted generator. The Turbine Battery is considered inoperable when bus N

jlSTONE-UNIT-2 83/48-1 Amendment No. Jpp,

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..- _ = _ _ . ._- . -. _- - _ - - _ _ . - . . _ - _ ._. -. . . -

3/4.8 (LECTRICAL POWER SYSTEMS BASES voltage is less than 125 volts D.C, thereby ensuring adequate ca)acity for

isolation functions via the feedwater regulating valves during tie onset of a steam line break.

The Turbine Battery Charger is not required to be included in Technical Specifications even though the Turbine Battery is needed to power backup Inverters 5 & 6 for a main steam line break inside containment

. coincident with a loss of a Class IE D.C. bus. This is due to the fact

., that feedwater isolation occurs within seccads from the onset of the event.

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NILLSTONE - UNIT 2 B3/48-2 AmendmentNo.Jpp, osu v -r- + - - ' - - _ _ _____a-_____ _ _m- ---____ -

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