Text

Proposed Tech Specs 3.8.1.1 Re AC Sources - Operating
	ML20140C064
Person / Time
Site:	Summer
Issue date:	03/26/1997
From:	; SOUTH CAROLINA ELECTRIC & GAS CO.
To:	;
Shared Package
ML20140C057	List: ML20140C064; RC-97-0065, TS Change Request - TSP 97-04,to License NPF-12,adding Footnote to TS 3.8.1.1, AC Sources - Operating, to Allow One Time Extension of Allowed Outage Time from 72 H to 7 Days to Perform on-line Maint on EDG B During Cycle 11;
References
	NUDOCS 9704020064
	Download: ML20140C064 (9)
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Document Control Desk

, Attachment I ,

, . TSP 970004 J RC-97-0065 l

Page 1 of 1 :

SCE&G - EXPLANATION OF CHANGES I

Paae Affected Bar Description of Chanae Reason for Chanae Section g 3/4 8.2 3.8.1.1 1&2 1) Add "" between " hours" VCSNS may need to perform

~

Action b.4 and "or" on the first line. on-line maintenance on EDG B during Cycle 11 to replace l

2) A footnote was added to the intercooler/ injector cooling !

Technical Specification water, jacket water, and lube l 3.8.1.1 Action b.4. The oi! heat exchangers. This i footnote allows a one time maintenance is expected to AOT of 7 days to perform take longer than the 72 hour8.333333e-4 days 0.02 hours 1.190476e-4 weeks 2.7396e-5 months maintenance on EDG B AOT allowed by the existing ,

during Cycle 11. Technical Specification. I l

9704020064 970326 PDR ADOCK 05000395-PDR P

. - - .. ~ - - - - - - - - - .~ - _ .- _ . . - - - - -. _

9 ELECTRICAL POWER SYSTEMS i

LIMITING CONDITION FOR OPERATION !

ACTION: (Continued) l

. 3. Within 2 hours2.314815e-5 days 5.555556e-4 hours 3.306878e-6 weeks 7.61e-7 months , verify that required systems, subsystems, trains components and devices that depend on the remaining EDG

! as a source of emergency power are also OPERABLE and in MODE 1, l 2, or 3, that the Turbine Driven Emergency Feed Pump is t

! OPERABLE. If these conditions are not satisfied within 2 hours2.314815e-5 days 5.555556e-4 hours 3.306878e-6 weeks 7.61e-7 months be in at least HOT STAND 8Y within the next 6 hours6.944444e-5 days 0.00167 hours 9.920635e-6 weeks 2.283e-6 months and in COLD i SHUTDOWN within the following 30. hours. '

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l 4. Restore the EDG to OPERABLE ' status within 72 hours8.333333e-4 days 0.02 hours 1.190476e-4 weeks 2.7396e-5 months r be in at I

! l '

least HOT STAND 8Y within the next 6 hours6.944444e-5 days 0.00167 hours 9.920635e-6 weeks 2.283e-6 months and in COLD SHUTDOWN l

within the following 30 hours3.472222e-4 days 0.00833 hours 4.960317e-5 weeks 1.1415e-5 months .

c. With one offsite circuit and one EDG inoperable:

I 1. Demonstrate the OPERABILITY of the remaining offsite A.C. l source by performing Surveillance Re'quirement 4.8.1.1.1 within one hour and at least once per 8 hours9.259259e-5 days 0.00222 hours 1.322751e-5 weeks 3.044e-6 months thereafter, and h j

. 1 l 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 Requirement 4.8.1.1.2.a.3 within 8 hours9.259259e-5 days 0.00222 hours 1.322751e-5 weeks 3.044e-6 months *, and

3. Within 2 hours2.314815e-5 days 5.555556e-4 hours 3.306878e-6 weeks 7.61e-7 months , verify that required systems, subsystems, trains, components and devices that depend on the remaining EDG as source of emergency power are also OPERABLE and in MODE 1, 2, or 3, that the Turbine Driven Emergency Feed Pump is OPERABLE. If these conditions are not satisfied within 2 hours2.314815e-5 days 5.555556e-4 hours 3.306878e-6 weeks 7.61e-7 months be in at least HOT STAND 8Y within the next 6 hours6.944444e-5 days 0.00167 hours 9.920635e-6 weeks 2.283e-6 months and in COLD SHUTDOWN within the following 30 hours3.472222e-4 days 0.00833 hours 4.960317e-5 weeks 1.1415e-5 months .

4. Restore one of the inoperable sources to OPERABLE status within 12 hours1.388889e-4 days 0.00333 hours 1.984127e-5 weeks 4.566e-6 months or be in at least HOT STAND 8Y within the next 6 hours6.944444e-5 days 0.00167 hours 9.920635e-6 weeks 2.283e-6 months and in COLD SHUTDOWN within the following 30 hours3.472222e-4 days 0.00833 hours 4.960317e-5 weeks 1.1415e-5 months , and

5. Restore the other A.C. power source (offsite circuit or diesel generator) to OPERABLE status in accordance with the provisions l of Section 3.8.1.1 Action Statement a. or b. , as appropriate, with the time requirement of that Action Statement based on the time of initial loss of the remaining inoperable A. C. power

source.

This test is required to be completed regardless of when the inoperable EDG is restored to OPERABILITY.

,- ~ -_ m . . ~ --=w 9 f % A ou b 4WaJ ohy b f ,Q'M 35 [

SUMIR Y INIT i 3/4 8-2 AMENDMENT NO. 77. 98 f

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ELECTRICAL POWER SYSTEMS LIMITING CONDITION FOR OPERATION ACTION: (Continued)

3. Within 2 hours2.314815e-5 days 5.555556e-4 hours 3.306878e-6 weeks 7.61e-7 months , verify that required systems, subsystems, trains, components and devices that depend on the remaining EDG as a source of emergency power are also OPERABLE and in MODE 1, 2, or 3, that the Turbine Driven Emergency Feed Pump is OPERABLE. If these conditions are not satisfied within 2 hours2.314815e-5 days 5.555556e-4 hours 3.306878e-6 weeks 7.61e-7 months be in at least HOT STANDBY within the next 6 hours6.944444e-5 days 0.00167 hours 9.920635e-6 weeks 2.283e-6 months and in COLD SHUTDOWN within the following 30 hours3.472222e-4 days 0.00833 hours 4.960317e-5 weeks 1.1415e-5 months .

4. Restore the EDG to OPERABLE status within 72 hours8.333333e-4 days 0.02 hours 1.190476e-4 weeks 2.7396e-5 months " or be in at l least HOT STANDBY within the next 6 hours6.944444e-5 days 0.00167 hours 9.920635e-6 weeks 2.283e-6 months and in COLD SHUTDOWN within the following 30 hours3.472222e-4 days 0.00833 hours 4.960317e-5 weeks 1.1415e-5 months .

c. With one offsite circuit and one EDG inoperable:

1. Demonstrate the OPERABILITY of the remaining offsite A.C.

source by pedorming Surveillance Requirement 4.8.1.1.1 within one hour and at least once per 8 hours9.259259e-5 days 0.00222 hours 1.322751e-5 weeks 3.044e-6 months 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 pedorming Surveillance Requirement 4.8.1.1.2.a.3 within 8 hours9.259259e-5 days 0.00222 hours 1.322751e-5 weeks 3.044e-6 months *, and

3. - Within 2 hours2.314815e-5 days 5.555556e-4 hours 3.306878e-6 weeks 7.61e-7 months , verify that required systems, subsystems, trains, components and devices that depend on the remaining EDG as source of emergency power are also OPERABLE and in MODE 1, 2, or 3, that the Turbine Driven Emergency Feed Pump is OPERABLE. If these conditions are not satisfied within 2 hours2.314815e-5 days 5.555556e-4 hours 3.306878e-6 weeks 7.61e-7 months be in at least HOT STANDBY'within the next 6 hours6.944444e-5 days 0.00167 hours 9.920635e-6 weeks 2.283e-6 months and in COLD SHUTDOWN within the following 30 hours3.472222e-4 days 0.00833 hours 4.960317e-5 weeks 1.1415e-5 months .

4. Restore one of the inoperable sources to OPERABLE status within 12 hours1.388889e-4 days 0.00333 hours 1.984127e-5 weeks 4.566e-6 months or be in at least HOT STANDBY within the next 6 hours6.944444e-5 days 0.00167 hours 9.920635e-6 weeks 2.283e-6 months and in COLD SHUTDOWN within the following 30 hours3.472222e-4 days 0.00833 hours 4.960317e-5 weeks 1.1415e-5 months , and

5. Restore the other A.C. power source (offsite circuit or diesel generator) to OPERABLE status in accordance with the provisions of Section 3.8.1.1 Action Statement a. or b., as appropriate, with the time requirement of that Action Statement based on the time of initial loss of the remaining inoperable A.C. power source.

This test is required to be completed regardless of when the inoperable EDG is restored to OPERABILITY.

" A one time allowed outage time of 7 days is allowed for EDG B during Cycle 11 for maintenance.

SUMMER - UNIT 1 3/48-2 Amendment No. 77,98,

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Document Control Desk 1

. Attachment ll

, . TSP 970004 RC-97-0065 i Page 1 of 3 ]

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SAFETY EVALUATION l

FOR REVISING THE EDG B ALLOWED OUTAGE TIME i

l ONE TIME FOR MAINTENANCE DURING CYCLE 11

' IN THE VIRGIL C. SUMMER NUCLEAR STATION TECHNICAL SPECIFICATIONS i 1

)

I Description of Amendment Reauest i

The Virgil C. Summer Nuclear Station (VCSNS) Emergency Diesel Generator (EDG) !

! Technical Specification (TS) (3.8.1.1 Action b.4) is being revised to add a one time i . allowance to extend the allowed outage time (AOT) from 72 hours8.333333e-4 days 0.02 hours 1.190476e-4 weeks 2.7396e-5 months to 7 days for EDG B.

l This one time AOT extension will allow maintenance to be performed while the plant is

' on-line to replace EDG B intercooler/ injector cooling water, jacket water, and lube oil heat exchangers (XHE0017B-HE1, HE2, & HE3)if necessary. Based on the analysis

of data gathered during Refuel 10, replacement of the heat exchangers may be prudent during Cycle 11.

4 i During Refuel 8 eddy current testing on the EDG A jacket water heat exchanger,

. indication of minimal tube degradation was identified. During Refuel 9 eddy current

! testing on the EDG A intercooler/ injector cooling water and lube oil heat exchangers, indcation of further tube degradation was identified. Based on the results of the eddy -

l- current testing during Refuel 9 all three EDG A heat exchangers are scheduled for j replacernent during Refuel 10. A detailed evaluation of the EDG A heat exchanger j tubes will be performed after the heat exchangers are removed to further correlate the

, degradation mechanism and evaluate the impact on the EDG B heat exchangers.

j Based on this correlation, further evaluations may need to be performed (i.e., eddy i

current testing on EDG B heat exchanger tubes) to determine if the EDG B heat l exchangers have sufficient margin to meet their design function. Previous eddy current

testing on EDG B heat exchangers has shown only minimal tube degradation.

Safety Evaluation i l

! VCSNS is proposing to change the TS to permit a one time extended AOT to perform i maintenance on EDG B during Cycle 11 if evaluations indicate replacement of the heat

exchangers is necessary. This TS change is required because the EDG B heat j exchangers cannot be replaced within the current Technical Specification AOT of 72 2

hours. Extending the AOT and performing the maintenance on-line will not significantly j increase the risk to the health and safoty of the pub.lic as discussed below. ;

i The Technical Specification change request will allow VCSNS EDG B to be out of l service for 7 days while on-line maintenance is being performed. Performance of this

maintenance on-line does not significantly increase the risk to the health and safety of ;

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Document Control Desk 1

Attachment 11 '

i TSP 970004 I. 'RC-97-0065

) Page 2 of 3 i l the general public. From an overall plant safety perspective, EDG maintenance

! performed during on-line constions is at least as safe as during shutdown conditions. l l Emergency Diesel Generator maintenance should be performed when plant conditions l

! more readly allow for decay heat removal via natural circulation in the Reactor Coolant ;

System (RCS) with steam dump from the steam generators (in the case when all AC l

power is lost) and with no other maintenance and operational activities in progress that could affect AC power supplies. A review of recent industry loss of ESF bus events i

! shows that the vast majority occur during plant outage conditions. There are system activities during shutdown conditions which could affect the ability to cool the core if a

!' loss of all AC power were to occur (i.e., RCS integrity may not be estabbshed [which

! eliminates decay heat removal via natural circulation], no water in the Steam Generator j [SG) U-tubes due to eddy current testing, no water on the SG secondary side, the

turbine driven emergency feedwater pump may be out of service for maintenance, ;

i etc.). If defueled, the attemate spent fuel pool cooling would be available upon loss of j AC power via inventory change-out using the diesel driven fire service water pump or ,

j gravity drain from the refueling water storage tank.

I !

l As discussed in the previous paragraph, pedorming EDG maintenance on-Ene ensures i j natural circulation is more readily available which allows time to restore AC power or :

find alternate sources of AC power before core damage can occur. Two alternate !

l sources of offsite power available to VCSNS are the Fairfield Pumped Storage and.

L Parr Hydro and Gas Turbine Stations. The Fairfield facility is located approximately 1

one mile from VCSNS and consists of eight 64 MW units, two of which have black start

[ capabiEty, that feed through separate step-up transformers and transmission lines to the VCSNS Switchyard. During a station blackout condition, system dspatch can j isolate the transmission lines at VCSNS via remote control from the dspatch office and .

i allow the Fairfield generation to be dedcated to supply VCSNS. Fairfield is manned 24 i hours a day so the capability to start the units and isolate generation can be l accomplished within the 4 hour4.62963e-5 days 0.00111 hours 6.613757e-6 weeks 1.522e-6 months station blackout coping time (actual time is

approximately 20 minutes). Parr Hydro is a 16 MW unit with black start capability

(located approximately three miles from VCSNS), which feeds the switchyard at Parr.

From the station service power at the switchyard, the four Gas Turbines (two 13 MW j and two 17 MW units) can be started. Parr Hydro is not manned continuously and may

require a call out to start, however, it can be started within the 4 hour4.62963e-5 days 0.00111 hours 6.613757e-6 weeks 1.522e-6 months station blackout

! coping time. During a station blackout condtion, the transmission lines at Parr can be i isolated so that the power flow can be dedicated to VCSNS. Although not specifically i credited in the design basis, these sources add dveise capability and reliability to the l VCSNS offsite sources. Emergency Diesel Generator work during the 7 day AOT will i be coordinated with the system dispatcher to ensure the availability of these offsite

! sources.

i k Probabilistic Risk Assessments (PRA) were run to determine the affects on the core

damage frequency (CDF) due to increasing the EDG AOT from 72 hours8.333333e-4 days 0.02 hours 1.190476e-4 weeks 2.7396e-5 months to 7 days, one i time for heat exchanger maintenance. The PRA results indicate an increase of less i

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Document Control Desk Attachment 11

TSP 970004 I

'RC-97-0065 j Page 3 of 3 i than 4%, not considering the offsetting benefit of increased availability of the EDG B during the outage. However, the most important factor in this analysis is EDG j unavailabiEty. A review of historical EDG unavailability data from the PRA and :

i Maintenance Rule data bases indicate an improving trend. SCE&G creusts inproved maintenance practices which have led to better control of EDG unavailability, ano

, increased reliability, it is important to note that the risk of performing ons additional 72

hour outage on an EDG in the 1990 - 1991 time frame,is now comparsole to

pedorming one additional 7 day outage. !

i This proposed change, and the resulting EDG unavailability time,is not expected to

exceed the Maintenance Rule criterion. The current performance of the EDG B, and i the low unavailability time logged to date, will allow an additional 7 days of outage time

{. without exceeding the target performance level. ;

i i

Finally, performing EDG maintenance on-line allows the dedication of resources to that !

4 task without competing for resources as occurs doring shutdown conditions. During j shutdown conditions, Operations has to deal with inany abnormal system alignments j and a large number of maintenance activities that could affect AC power supplies.

i During power operations, no planned activities will be allowed during EDG maintenance

that could degrade safety. Also, maintenance will not begin if adverse weather (i.e.,

! tornadoes and hurricanes)is expected.

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Document Control Desk Attachment lli j , , TSP 970004

! RC-97-0065 Page 1 of 3 i

NO SIGNIFICANT HAZARDS EVALUATION FOR REVISING THE DEFINITION FOR i

EDG B ONE TIME AOT EXTENSION i

IN THE VIRGIL C. SUMMER NUCLEAR STATION TECHNICAL SPECIFICATIONS

! Description of Amendment Reauest 1

i The Virgil C. Summer Nuclear Station (VCSNS) Emergency Diesel Generator (EDG) i Technical Specification (TS) (3.3.1.1 Action b.4) is being revised to add a one time allowance to extend the allowed outage time (AOT) from 72 hours8.333333e-4 days 0.02 hours 1.190476e-4 weeks 2.7396e-5 months to 7 days for EDG B.

, This one time AOT extension will allow maintenance to be performed while the plant is i on-line to replace EDG B intercooler/ injector cooling water, jacket water, and lube oil

heat exchangers (XHE0017B-HE1, HE2, & HES) if necessary. Based on the analysis i of data gathered during Refuel 10, replacement of the heat exchangers may be

} prudent during Cycle 11.

l During Refuel 8 eddy current testing on the EDG A jacket water heat exchanger,

! indication of minimal tube degradation was identified. During Refuel 9 eddy current testing on the EDG A intercooler/ injector cooling water and lube oil heat exchangers, i

indcation of further tube degradation was identified. Based on the results of the eddy j current testing during Refuel 9, all three EDG A heat exchangers are scheduled for j replacement during Refuel 10.' A detailed evaluation of the EDG A heat exchanger

'~

tubes will be performed after the heat exchangers are removed to further correlate the i degradation mechanism and evaluate the impact on the EDG B heat exchangers.

Based on this correlation, further evaluations may need to be pedormed (i.e., eddy current testing on EDG B heat exchanger tubes) to determine if the EDG D heat exchangers have sufficient margin to meet their design function. Previous eddy current -

testing on EDG B heat exchangers has shown only minimal tube degradation.

Basis for No Sionificance Hazards Consideration Determination South Carolina Electnc & Gas Company (SCE&G) has evaluated the proposed changes to the VCSNS TS described above against the Significant Hazards Criteria of 10 CFR 50.92 and has determined that the changes do not involve any significant hazard. The following is provided in support of this conclusion.

1. Does the change involve a significant increase in the probability or consequences of an accident previously evaluated?

The proposed change will allow a one time EDG AOT increase from 72 hours8.333333e-4 days 0.02 hours 1.190476e-4 weeks 2.7396e-5 months to 7 days to perform on-line maintenance on EDG B during Cycle 11. This change

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Document Contral Desk j Attachment lli i

, , TSP 970004

RC-97-0065 i Page 2 of 3

! does not significantly affect the probability of an accident previously evaluated.

l Inoperability of an EDG is not an initiator of any analyzed event. Extendng the i EDG AOT to perform on-line maintenance will not significantly affect the

consequences of an accident. During power operations, the capability of being

able to remove decay heat via natural circulation is greater (in the case where all AC power is lost). This increases the likelihood of restoring AC puwer or i

finding an alternate source prior to core damage occurring. Attemate AC power j sources are available which can supply AC power to VCSNS (one of the sources can be made available in approximately 20 minutes). During shutdown l conditions, heat removal via natural circulation may not be available due to RCS

! integrity not being maintained, lack of water in the SG U-tubes, lack of water on

! the SG secondary side, or the turbine driven' emergency feedwater pump being i out of service. During power operations, no planned activities will be allowed during EDG maintenance that could degrade safety. PRA results indicate an j increase in core damage frequency (CDF) of less than 4%. This increase is

offset by the reduction in outage risk (most loss of ESF bus events occur during

outage conditions), and the ability to better control concurrent activities and j focus resources on line. Therefore, the change does not involve a significant ;

j increase in the probability or consequences of an accident previously evaluated.

2. Does the change create the possibility of a new or different kind of accident

! from any accident previously evaluated?

! The proposed change will allow a one time EDG AOT increase from 72 hours8.333333e-4 days 0.02 hours 1.190476e-4 weeks 2.7396e-5 months to j 7 days to perform on-line maintenance on EDG B during Cycle 11. Although i the change allows replacement of EDG heat exchangers, the change will not

involve a significant change in the design or operation of the plant. This change l will not involve any new or unusual Operator actions. The change will not i

impose any new or different requirements or eliminate any existing i requirements. Therefore, the change does not create the possibility of a new or

different kind of accident from any accident previously evaluated.

3. Does this change involve a significant reduction in margin of safety?

1 The proposed change will allow a one time EDG AOT increase from 72 hours8.333333e-4 days 0.02 hours 1.190476e-4 weeks 2.7396e-5 months to 7 days to perform on-line maintenance on EDG B during Cycle 11. Extending the AOT to 7 days to replace EDG B heat exchangers on-line will not j significantly affect the margin of safety. There are two alternate sources of AC 3 power which can be made available solely to VCSNS (one of the sources can 1 be made available in approximately 20 minutes). Performing the maintenance

, on-line allows natural circulation to be more readily available. Additionally, on-

line performance allows dedication of resources to this task without competition i from other activities that would occur during a shutdown. PRA results indicate 4

an increase in CDF of less than 4%. This increase is offset by the reduction in J

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+& Ja %& ,,aMn w4-E'%e i- .

, Docuneent Contr@l Desk-l Attachment lil TSP 970004

' RC-97-0065

Page 3 of 3 L

i o

j outage risk (most loss of ESF bus events occur during outage conditions), and i the ability to better control concurrent activities and focus resources on-line. !

l Therefore, the change does not involve a significant reduction in a margin of

safety i

Pursuant to 10 CFR 50.91, the preceding analyses provide a determination that the i proposed TSCR poses no significant hazard as delineated by 10 CFR 50.92.

i i

l Environmental Assessment t

, This proposed Technical Specifications change has been evaluated against criteria for j and identification of licensing and regulatory actions requiring environmental i assessment in accordance with 10 CFR 51.21. It has been determined that the i

proposed change meets the criteria for categorical exclusion as provided for under 10 CFR 51.22(c)(9). The following is a discussion of how the proposed Technical Specification change meets the criteria for categoncal exclusion.

10 CFR 51.22(c)(9): Although the proposed change involves change to requirements with respect to inspection or Surveillance Requirements, 1

(i) proposed change involves No Significance Hazards Consideration (refer to the l No Significance Hazards Consideration Determination section of this Technical Specification Change Request);

(ii) there are no significant changes in the types or significant increase in the amounts of any effluents that may be released offsite since the proposed i changes do not affect the generation of any radioactive effluents nor do they affect any of the permitted release paths; and i (iii) there is no significant increase in indvidual or cumulative occupational radiation i exposure.

i Accordingly, the proposed change meets the eligibility criteria for categorical exclusion set forth in 10 CFR 51.22(c)(9). Based on the aforementioned and pursuant to 10 CFR 51.22 (b), no environmental assessment or environmentalimpact statement need be prepared in connection with issuance of an amendment to the Technical Specifications incorporating the proposed change requested.

ML20140C064

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