Text

Proposed Tech Specs 3.8.1 Re AC Electrical Sources
	ML20117N585
Person / Time
Site:	Vogtle
Issue date:	09/13/1996
From:	; GEORGIA POWER CO.
To:	;
Shared Package
ML20117N582	List: ML20117N581; ML20117N585;
References
	NUDOCS 9609190292
	Download: ML20117N585 (21)
	v • d • e

- - - --_ _ _ _ . _ . .. -_ _. -. ,

1 AC Sources -- Operating l 3.8.1 3.8 ELECTRICAL POWER SYSTEMS 3.8.1 AC Sources -- Operating l LCO 3.8.1 The following AC electrical sources shall be OPERABLE:

l

a. Two qualified circuits between the offsite l transmission network and the onsite Class 1E AC Electrical Power Distribution System; and

b. Two diesel generators (DGs) capable of supplyin onsite Class 1E power distribution subsystem (s)g the .

Automatic load sequencers for Train A and Train B ESF buses shall be OPERASLE.

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

l l

l ACTIONS r_ % __...___..----------------N0TE---------------------- ------_--

The Standby Aurii;;r" sformer (SAT) is avai applicationtoonly]

one of the four 4.16 kV ES =a n time for Units 1 and 2 for use in accordance with Specif' .8.1 as offsite source or to meet l the requireme e C0 3.8.1 condition.

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CONDITION REQUIRED ACTION COMPLETION TIME l

! A. One required offsite A.1 Perform SR 3.8.1.1 1 hour1.157407e-5 days 2.777778e-4 hours 1.653439e-6 weeks 3.805e-7 months l circuit inoperable. for required OPERABLE offsite circuit. AND Once per 8 hours9.259259e-5 days 0.00222 hours 1.322751e-5 weeks 3.044e-6 months thereafter i

AND (continued) r l

Vogtle Units 1 and 2 3.8-1 Amendment No. 96 (Unit 1)

Amendment No. 74 (Unit 2) 9609190292 960913 -

PDR ADOCK 05000424 '

P PDR

r --

, p' AC Sources - Operating 3.8.1 ACTIONS CONDITION REQUIRED ACTION COMPLETION TIME A. (continued) A.2 Declare required 24 hours2.777778e-4 days 0.00667 hours 3.968254e-5 weeks 9.132e-6 months from feature (s) with no discovery of no offsite power offsite power to available inoperable one train i when its redundant concurrent with l l required feature (s) inoperability of is inoperable. redundant required feature (s)

AND A.3 Restore required 72 hours8.333333e-4 days 0.02 hours 1.190476e-4 weeks 2.7396e-5 months offsite circuit to l OPERABLE status. AND g

ays from l

discovery of

(

failure to meet LC0 l

l B. One DG inoperable. . Verify calendar date I hour not fall on or l withi ly 15

through N ber 15.

l 8.2 Verify SAT avail I hour l

Once pe hours

. thereafter l

l AN l

B./ Perform SR 3.8.1.1 1 hour1.157407e-5 days 2.777778e-4 hours 1.653439e-6 weeks 3.805e-7 months i for the required offsite circuit (s). AND AND Once per 8 hours9.259259e-5 days 0.00222 hours 1.322751e-5 weeks 3.044e-6 months thereafter (continued)

Vogtle Units 1 and 2 3.8-2 Amend:aent No. 96 (Unit 1)

Amendment No. 74 (Unit 2)

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

, r AC Sources -- Operating

, 3.8.1 ACTIONS A

CONDITION REQUIRED ACTION COMPLETION TIME B. (continued) B.[ Declare required 4 hours4.62963e-5 days 0.00111 hours 6.613757e-6 weeks 1.522e-6 months from

~

f, feature (s) supported discovery of by the inoperable DG Condition B

) inoperable when its concurrent with

. required redundant inoperability of j

feature (s)is redundant 4 inoperable, required feature (s) 1 l

AND B. 1 Determine OPERABLE DG 24 hours2.777778e-4 days 0.00667 hours 3.968254e-5 weeks 9.132e-6 months is not inoperable due to common cause failure.

QB B.,$.2 Perform SR 3.8.1.2 24 hours2.777778e-4 days 0.00667 hours 3.968254e-5 weeks 9.132e-6 months ,

$ for OPERABLE DG. 1 AND 1 Verify an enhanced 72 h rs lack-start I co ion turbine generato TG) is functional by Within 72 hours8.333333e-4 days 0.02 hours 1.190476e-4 weeks 2.7396e-5 months verifying the CT rior to entry l the black star Condition B l diesel gene or ;

starts a achieves stead tate voltage ,

s and requency. '

0 (continued)

Vogtle Units 1 and 2 3.8-3 Amendment No. 96 Unit 1 Amendment No. 74 Unit 2

r . .

-)

l j V AC Sources - Operating 3.8.1 l . .

ACTIONS ,

CONDITION REQUIRED ACTION COMPLETION TIME B. (continued) bE. . Start and run at 72 hours8.333333e-4 days 0.02 hours 1.190476e-4 weeks 2.7396e-5 months e CTG while in Condi ;

n B for preplanned .

maintenance. .

72 h.un l

[gh pm Restore DG to M'ty: 'x discogr/ I of B.[I OPERABLE status. d .; . . . , of .

i , _ . , . _ _ _ ___. ,

~-~

i ~ d'" ~ ~ ~

(failun ho

) meat l.40

__Awo

~ _

w l C.1 Restore DG to and associated ;

Completion T' '

u C

J.I Two required offsite JK1 Declare required 12 hours1.388889e-4 days 0.00333 hours 1.984127e-5 weeks 4.566e-6 months from

( circuits inoperable. feature (s) inoperable when its redundant discovery of Condition g C required feature (s) concurrent with is inoperable. inoperability of redundant required features AND C.

p.'2 Restore one required 24 hours2.777778e-4 days 0.00667 hours 3.968254e-5 weeks 9.132e-6 months offsite circuit to OPERABLE status.

(continued) !

1 f

~

l Vogtle Units 1 and 2 3.8-4 Amendment No. 96 (Unit 1) I Amendment No. 74 (Vnit 2) l l

i AC Sources - Operating 3.8.1 ACTIONS (continued) l CONDITION REQUIRED ACTION COMPLETION TIME l

/. One required offsite - - - - - - - - - - - - N O T E - - - - - - - - -- - - -

-p circuit inoperable. Enter applicable Conditions and Required Actions of AND LC0 3.8.9, " Distribution Systems - Operating," when One DG inoperable. Condition JL *s entered with noACpowerhourcetooneor more trains.b

__________..... D._____________

L

[.1 Restore required 12 hours1.388889e-4 days 0.00333 hours 1.984127e-5 weeks 4.566e-6 months offsite circuit to 9 OPERABLE status.

l QR

/.2 Restore DG to 12 hours1.388889e-4 days 0.00333 hours 1.984127e-5 weeks 4.566e-6 months

, OPERABLE status.

.9 i

/. Two DGs inoperable. [.1 Restore one DG to 2 hours2.314815e-5 days 5.555556e-4 hours 3.306878e-6 weeks 7.61e-7 months PERABLE status.

l 6 E l

/. One automatic load f.1 Restore automatic 12 hours1.388889e-4 days 0.00333 hours 1.984127e-5 weeks 4.566e-6 months sequencer inoperable. load sequencer to F F OPERABLE status.

(continued) l i

l l

Vogtle Units 1 and 2 3.8-5 Amendment No. 96 (Unit 1)

Amendment No. 74 (Unit 2) l l

r . .

AC Sources - Operating 3.8.1 I

ACTIONS (continued)

CONDITION- REQUIRED ACTION COMPLETION TIME

. Required Action and .1 Be in MODE 3. 6 hours6.944444e-5 days 0.00167 hours 9.920635e-6 weeks 2.283e-6 months associated Completion TimeofConditionA,8 AND i C, D, E, Fg;3E!!!pnot l met. M2 Be in MODE 5. 36 hours4.166667e-4 days 0.01 hours 5.952381e-5 weeks 1.3698e-5 months I

W R Q

. Requi Acti B.4, B. . .5.2, or B.7 a ss "ated Co etion Tim t t.

Three or more required

[Q AC sources inoperable. /1 Enter LC0 3.0.3. Immediately g

l l

l I

l Vogtle Units 1 and 2 3.8-6 Amendment No. 96 (Unit 1 l Amendment No. 74 (Unit 2 l

AC Sources - Operating B 3.8.1 I

BASES l

i LCO train. For the DGs, separation and independence are !

(continued) complete.

For the offsite AC sources, separation and independence are I to the extent practical. A circuit may be connected to more than one ESF bus while the bus is being transferred to the ;

other circuit, l

l APPLICABILITY The AC soarces and sequencers are required to De OPERABLE in MODES 1, 2, 3, and 4 to ensure that:

a. Acceptable fuel design limits and reactor coolant l

pressure boundary limits are not exceeded as a result of A00s or abnormal transients; and

b. Adequate core cooling is provided and containment OPERABILITY and other vital functions are maintained in the event of a postulated DBA.

The AC power requirements for MODES 5 and 6 are covered in LC0 3.8.2, "AC Sources - Shutdown."

ACTIONS F Note prior to the ACTIONS table prompts the user th end th AT is being applied in accordance with LC0 3. as an offsi ircuit for an ESF bus or to meet the uirements of an LC 8.1 Condition (SAT available) f an ESF bus, it is not 'avai le" for any of the other ree 4.16 kV ESF buses during tha ime. The SAT is ilable when it is:

Operable in accor wi plant procedures;

Not being applied t ny c, he four 4.16 kV ESF buses for Units 1 and n accordan ith Specification 3.8.1 as eith an offsite source to meet the requiremen of an LC0 3.8.1 Conditi and,

Not viding power to the other unit when unit in MODE 5 or 6 or defueled.

J l

l.

(continued)

Vogtle Units 1 and 2 B 3.8-5 Revision No. 0

l AC Sources - Operating I 8 3.8.1 1 BASES I

ACTIONS A.1 (continued)

To ensure a highly reliable power source remains with one offsite circuit inoperable, it is necessary to verify the OPERABILITY of the remaining required offsite circuit on a l more frequent basis. Since the Required Action only '

specifies " perform," a failure of SR 3.8.1.1 acceptance criteria does not result in a Required Action not met.

the However, if a second required circuit fails SR 3.8.1.J,for secondoffsitecircuitisinoperable,andCondition7,-

two offsite circuits inoperable, is entered.

4 A.2 Required Action A.2, which only applies if the train cannot be powered from an offsite source, is intended to provide assurance that an event coincident with a single failure of the associated DG will not result in a complete loss of safety function of critical redundant required features.

These features are powered from the redundant AC electrical power train. This includes motor driven auxiliary feedwater pumps. Single train systems, such as turbine driven auxiliary feedwater pumps, may not be included.

The Completion Time for Required Action A.2 is intended to allow the operator time to evaluate and repair any discovered inoperabilities. This Completion Time also allows for an exception to the normal " time zero" for beginning the allowed outage time " clock." In this Required Action, the Completion Time only begins on discovery that both:

a. The train has no offsite power supplying it loads; and

b. A required feature on the other train is inoperable.

If at any time during the existence of Condition A (one offsite circuit inoperable) a redundant required feature subsequently becomes inoperable, this Completion Time begins to be tracked.

Discovering no offsite power to one train of the onsite Class 1E Electrical Power Distribution System coincident with one or,more inoperable required support or supported (continued)

Vogtle Units 1 and 2 B 3.8-6 Revision No. 0

I l .,.

AC Sources - Operating B 3.8.1 BASES l

ACTIONS A.2 (continued) features, or both, that are associated with the other train l that has offsite power, results in starting the Completion Times for the Required Action. Twenty-four hours is acceptable because it minimizes risk while allowing time for restoration before subjecting the unit to transients associated with shutdown.

The remaining OPERABLE offsite circuit and DGs are adequate to supply electrical power to Train A and Train B of the onsite Class 1E Distribution System. The 24 hour2.777778e-4 days 0.00667 hours 3.968254e-5 weeks 9.132e-6 months Completion Time takes into account the component OPERABILITY of the t redundant counterpart to the inoperable required feature.

Additionally, the 24 hour2.777778e-4 days 0.00667 hours 3.968254e-5 weeks 9.132e-6 months Completion Time takes into account the capacity and capability of the remaining AC sources, a reasonable time for repairs, and the low probability of a DBA occurring during this period.

A.3 l

According to Regulatory Guide 1.93 (Ref. 6), operation may continue in Condition A for a period that should not exceed l 72 hours8.333333e-4 days 0.02 hours 1.190476e-4 weeks 2.7396e-5 months . With one required offsite circuit inoperable, the reliability of the offsite system is degraded, and the potential for a loss of offsite power is increased, with l

attendant potential for a challenge to the unit safety systems. In this Condition, however, the remaining OPERABLE )

offsite circuit and DGs are adequate to supply electrical l power to the onsite Class 1E Distribution System. ;

1 The 72 hour8.333333e-4 days 0.02 hours 1.190476e-4 weeks 2.7396e-5 months Completion Time takes into account the capacity I and capability of the remaining AC sources, a reasonable i time for repairs, and the low probability of a DBA occurring i during this period.

I The second Completion Time for Required Action A.3 establishes a limit on the maximum time allowed for any combination of required AC power sources to be inoperable i during any single contiguous occurrence of failing to meet '

the LCO. If Condition A is entered while, for instance, a l DG is inoperable and that DG is subsequently returned l OPERABLE, the LC0 may already have been not met for up to 1

C ; ty:. This could lead to a total of M i p , since U IW hWfS (continued)

Vogtle Units 1 and 2 B 3.8-7 Revision No. O l

[

,- p-l AC Sources - Operating l

! B 3.8.1 '

BASES I

! l ACTIONS A.3 (continued) .g gogg l initial failure to meet the LCO, to restore the o fsite !

circuit. At this time, a DG could again become in pera the circuit restored OPERABLE, and an pitional 4 i-[ble l

[/oroMd/089dop) W i n i g ad a; u. SAT ev;il;bilit # #allowed orior to 4

complete restoration of the LCO. The. W tay Completion Time provides a limit on the time allowed in a specified ,

condition after discovery of failure to meet the LCO. This limit is considered reasonable for situations in which l Conditions A and B are entered concurrently. The "AND" (,

connector between the 72 hour8.333333e-4 days 0.02 hours 1.190476e-4 weeks 2.7396e-5 months and W day Completion Times I

means that both Completion Times apply simultaneously, and the more restrictive Completion Time must be met.

b Tracking the .W day Completion Time is a requirement for i

beginning the Completion Time " clock" that is in addition to g the normal Completion Time requirements. With respect to the N day Completion Time, the " time zero" is specified as commencing at the time LC0 3.8.1 was initially not met, ,

instead of at the time Condition A was entered. This results in the requirement when in this Condition to track the time elapsed from both the Condition A " time zero" and l the " time zero" when LC0 3.8.1 was initially not met. ;

I .1 f i

Requ d Action B.1 addresses the concern that there may be l an iner ed potential for weather-related events that c d cause elec cal system grid disturbances and/or dam to l the switchyar r electrical service to the switc rd i during the perio time from July 15 throug vember 15.

If at any time while Condition B Requir ction B.1

cannot be met, then Con n C become plicable, and the

! DG must be restored to OPER st within 72 hours8.333333e-4 days 0.02 hours 1.190476e-4 weeks 2.7396e-5 months from entry into Condition C. Note while the Completion Time of 72 hours8.333333e-4 days 0.02 hours 1.190476e-4 weeks 2.7396e-5 months begins upon en into ition C, the total l

time to restore an ino able DG cannot eed 14 days (per

! the Completion Ti Required Action B.7 . Therefore, due to the constr ' of Required Action B.1, a DG

1 not be voluntari removed from service for maintenance t would requ' an extended Completion Time during the period m

! 15 through November 15. !

(continued) i Vogtle Units 1 and 2 B 3.8-8 Revision No. O i

? .

I' AC Sources - Operating l B 3.8.1 t

l BASES i

ACTIONS l

l (continued) fB.2 e 13.8/4.16 kV Standby Auxiliary Transformer (SAT) is a l i qu ified offsite circuit that may be connected to the t onsi Class 1E distribution system independently of th i RATS a may be utilized to meet the LC0 3.8.1 requir nts for an o ite circuit. Its availability permits a extension o the allowable out-of-service time for a DG to l 14 days from e discovery of failure to meet L 3.8.1.

l The SAT is ava ble when it is:

Operable in a ordance with plant pr edures;

Not being applie o any of the ur 4.16 kV ESF buses i for Units 1 and 2 i accordanc with Specification 3.8.1 as either an o ite s rce or to meet the requirements of an LC0 .8 Condition; and,

Not providing power tc- he ther unit when that unit )

is in MODE 5 or 6 or efuele When one or more of ese criteria ar not satisfied, the l l SAT is not availa . These criteria a structured to l ensure that the T is available as an a rnate offsite source to sup rt the extended DG Completi Time of 14 days. Ther ore, when a DG is inoperable, i is necessary to verify e availability of the SAT within o hour and i once pe hours thereafter. If Required Action .2 is not met o the status of the SAT changes after Require ction i

B. s initially met, Condition C must be entered i currently.

B./

To ensure a highly reliable power source remains with an inoperable DG, it is necessary to verify the availability of ;

the offsite circuits on a more frequent basis. Since the Required Action only specifies " perform," a failure of I l

SR 3.8.1.1 acceptance criteria does not result in a Required l l Action being not met. However, if a circuit fails to pass SR 3.8.1.1, it is inoperable. Upon offsite circuit inoperability, additional Conditions and Required Actions must then be entered.

l (continued)

Vogtle Units 1 and 2 B 3.8-9 Revision No. O

' ', e AC Sources - Operating B 3.8.1 BASES !

ACTIONS (continued)

Dd

[

Required Action B.7 is intended'to provide assurance that a loss of offsite power, during the period that a DG is inoperable, does not result in a' complete loss of safety function of critical systems. These features are designed with redundant safety related trains. This includes motor driven auxiliary feedwater pumps. Single train systems, such as turbine driven auxiliary feedwater pumps, are not included.- Redundant required feature failures consist of inoperable features associated with a train, redundant to the train that has an inoperable DG. .

TheCompletionTimeforRequiredActionB./isintendedto allow the operator time to evaluate and repair any discovered inoperabilities. This Completion Time also allows for an exception to the normal " time zero" for beginning the allowed outage time " clock." In this Required 4 Action, the Completion Time only begins on discovery that both:

a. An inoperable DG exists; and l

b. A required feature on the other train (Train A or Train B) is inoperable.

'If at any time during the existence of this Condition (one DG inoperable) a required feature subsequently becomes inoperable, this Completion Time would begin to be tracked.

Discovering one required DG inoperable coincident with one or more inoperable required support or supported features, or both, that are associated with the OPERABLE DG, results in starting the Completion Time for the Required Action.

Four hours from the discovery of these events existing concurrently is acceptable because it minimizes risk while allowing time for restoration before subjecting the unit to transients associated with shutdown.

In this Condition, the remaining OPERABLE DG and offsite circuits are adequate to supply electrical power to the onsite Class 1E Distribution System. Thus, on a component i basis, single failure protection for the required feature's

! function may have been lost; however, function has not been j lost. The 4 hour4.62963e-5 days 0.00111 hours 6.613757e-6 weeks 1.522e-6 months Completion Time takes into account the

! (continued)

I Vogtle Units 1 and 2 B 3.8-10 Revision No. 0 ,

'. c )

AC Sources - Operating B 3.8.1 BASES ACTIONS B.# (continued)

OPERABILITY of the redundant counterpart to the inoperable required feature. Additionally, the 4 hour4.62963e-5 days 0.00111 hours 6.613757e-6 weeks 1.522e-6 months Completion Time takes into account the capacity and capability of the

remaining AC sources, a reasonable time for repairs, and the low probability of a DBA occurring during this period.

3 .3 B.g.1 and B.f.2 3

Required Action B.)f.1 provides an allowance to avoid unnecessary testing of the OPERABLE DG. If it can be determined that the cause of the inoperable DG does not exist on the OPERABLE DG, SR 3.8.1.2 does not have to be performed. If the cause of inoperability exists on the other DG, the other DG would be declared inoperable upon discovery and Condition F of LC0 3.8.1 would % ea. -- 3 Once the failure is repaired, the co cause failure no longer exists, and Required Action B. 1 is satisfied. If the cause of the initial inoperable DG cannot be confirmed not to exist on the remaining DG, performance of SR 3.8.1.2 suffices to provide assurance of continued OPERABILITY of that DG.

3 In the event the inoperable DG is re tored to JPERABLE status prior to completing either B.T.1 or B./.2, the applicable plant procedures will continue to require the evaluation of the common cause possibility. This continued evalcation, however, is no longer under the 24 hour2.777778e-4 days 0.00667 hours 3.968254e-5 weeks 9.132e-6 months constraint imposed while in Condition B.

According to Generic Letter 84-15 (Ref. 7), 24 hours2.777778e-4 days 0.00667 hours 3.968254e-5 weeks 9.132e-6 months is reasonable to confirm that the OPERABLE DG is not affected by the same problem as the inoperable DG.

r 1 R li_.1 and B.6.2 Required Ac B.6.1 provides assurance that nhanced black-start combu n turbine generato ) is functional j when a DG is out of s'e _e for er than 72 hours8.333333e-4 days 0.02 hours 1.190476e-4 weeks 2.7396e-5 months . l Required Action B.6.1 is o plicable provided that the two enhanced black-s TGs ha ombined reliability of l

> 95% based o inimum of 20 tests pe ced black- I start C quarterly testing thereafter. T uarterly l

I i (continued) l Vogtle Units 1 and 2 B 3.8-11 Revision No. 0 l l

c

r- . .

.* e z.

AC Sources - Operating l B 3.8.1 BASES ACTIONS .6.1 and B.6.2 (continued) i tes g will subject each enhanced black-start CTG to a l start d load-run test. The black-start diesel gener or will als be tested quarterly, but separately from th l

enhanced b ck-start CTGs. Required Action B.6.1 m be met by starting ither of the enhanced black-start CTG and the black-start d sel generator and verifying that ey achieve steady state yo age and frequency. The black-' art diesel generator may be arted separately.

If a DG is to be remo d from service volu arily for greater than 72 hours8.333333e-4 days 0.02 hours 1.190476e-4 weeks 2.7396e-5 months , 't may be advanta ous to test an enhanced black-start CTG rior to takin the DG out of service. In such cases wh e advance otice of removing a DG from service is available Requir d Action B.6.1 may be performed up to 72 hours8.333333e-4 days 0.02 hours 1.190476e-4 weeks 2.7396e-5 months prio to try into Condition B.

In other cases, Required Action .6.1 must be performed within 72 hours8.333333e-4 days 0.02 hours 1.190476e-4 weeks 2.7396e-5 months after entry in ndition B. If the reliability of the enhanced b ck-s rt CTGs has not been demonstrated or maintained 95%, the ption of starting and running any one of the si TGs while i Condition B is available in the form of equired Action .6.2. In the event of preplanned mai tenance that would xceed 72 hours8.333333e-4 days 0.02 hours 1.190476e-4 weeks 2.7396e-5 months , any one of the six CT must be started prio to entry into Condition B and all ed to run for the duratio of Condition B. Othe ise, any one of the six CTGs ust be started within 7 hours8.101852e-5 days 0.00194 hours 1.157407e-5 weeks 2.6635e-6 months (and allowed to run) afte entry into Condition . If the running CTG should fail w 'le in Condition B, y one of the remaining CTGs must be st ted within 1 ho . If one of the six CTGs cannot be starte within 1 ur, Condition C becomes applicable. Note tha Required ction B.6.1 requires that one of the two enhance black- art CTGs be started, but any one of the six CTGs coul e started to satisfy Required Action B.6.2. Since a CTG s started and running while the DG is inoperable, it is y n necessary that the CTG have enhanced black-start apability.

B.h

[The-av.ailabilityoftheSATprovW: ;,, ouuitional AC source f which permits ooarm L ,d= w a oeriod not to 1

,ey:amHtTays from discovery of failure to meetM l (continued)

Vogtle Units 1 and 2 B 3.8-12 Revision No. O

^

l

/(/Mycet /44 /g CuoW/84Accordin O M A pe//o O'/ AC-b ke- td&y Sources Operating Gwde L.3kuN Mp/etceed 12 b odd. B 3.8.1 1 ggsg5 COfscily andCufwb;///

St Ibnurkn AC anwrs).-

r L v 4

ACTIONS In Condition B, the remaining 0PERABLE DG and offsite circuits are adequate to supply electrical p er to the onsite Class 1E Distribution S / stem. The 10 d:y Completion Time takes into account the = :r rd =li di'it3 =d

=ild: hy ef ;ff; ne ~..cca d.; t; th: UT, a reasonable time for repairs, and the low probability of a DBA occurring 7

during this period.

The Completion Time for Required Action B also establishes a limit on the maximum time allowed for any combination of required AC power sources to be inoperable during any single contiguous occurrence of failing to meet the LCO. If l Condition B is entered while, for instance, an offsite l

circuit is inoperable, the LC0 may already have been not met l for up to 72 hours8.333333e-4 days 0.02 hours 1.190476e-4 weeks 2.7396e-5 months . If the offsite circuit is restored within the required 72 hours8.333333e-4 days 0.02 hours 1.190476e-4 weeks 2.7396e-5 months , this could lead to a total of fqq houn-+ U d;3;, since initial failure to meet the LCO, to restore compliance with the LC0 (i.e.. restore the DG).4 However, th f4/ AS//eW,0rld84/63 l keKdayCompletionTimeprovidesalimitontimeallowed a specified condition after discovery of failure to meet i

l c/im M couh a4aig Q q the LCO. This limit is considered reasonable for situations l /4,pagg,Q g inwhichConditionsAandB(andconsequentlyCondition/)

gg are entered concurrently. I) add at Md/// pas / y[f,,fy i Tracking the day Completion Time is a requirement for beginning the Completion Time " clock" that is in addition to (gggjgfh the normal Completion Time requirements. With respect to 4//**dp//u -/r cu the Completion Time, the " time zero" is specified as i

e//4 commencing at the time LC0 3.8.1 was initially not met,

(/hs/draffog oQ 4 cod instead of at the time Condition B was entered. This results in the requirement when in this Condition to track the time elapsed from both the Condition B " time zero" and the " time zero" when LC0 3.8.1 was initially not met, i

I i If the DG in ~ ity fa n or within July 15 through I November 15 in accor ' h Required Action B.1, or if the availability he SAT can verified and/or maintained ccordance with Require B.2, or if no l CTG me e requirements of either Required 8.6.1

' . or . 2, the DG must be restored to OPERABLE status w 'n 2 hours2.314815e-5 days 5.555556e-4 hours 3.306878e-6 weeks 7.61e-7 months . The 72-hour Completion Time begins upon entry J

4 ,

(continued)

Vogtle Units 1 and 2 B 3.8-13 Revision No. O

I AC Sources - Operating l B 3.8.1 BASES e

ACTIONS (continued) into Condi . However, the total time to re e an inoperable DG can xceed 14 days (per t mpletion Time of Required Action B.5 .

The Completion Time of 72 s i e absence of the SAT) is consistent with R tory Guide 1. ef. 6). The 72-hour Complet' ime takes into account t apacity and capabilit he remaining AC sources, a reasona time for rs, and low probability of a DBA occurring du '

s period.

Sg .1 and #.2 Required Action .1, which applies when two offsite circuits are inoperable, is intended to provide assurance that an event with a coincident single failure will not result in a complete loss of redundant required safety functions. The Completion Time for this failure of redundant required features is reduced to 12 hours1.388889e-4 days 0.00333 hours 1.984127e-5 weeks 4.566e-6 months from that allowed for one train without offsite power (Required Action A.2). The rationale for the reduction to 12 hours1.388889e-4 days 0.00333 hours 1.984127e-5 weeks 4.566e-6 months is that Regulatory Guide 1.93 (Ref. 6) allows a Completion Time of 24 hours2.777778e-4 days 0.00667 hours 3.968254e-5 weeks 9.132e-6 months for two required offsite circuits inoperable, based upon the assumption that two complete safety trains are OPERABLE.

When a concurrent redundant required feature failure exists, this assumption is not the case, and a shorter Completion Time of 12 hours1.388889e-4 days 0.00333 hours 1.984127e-5 weeks 4.566e-6 months is appropriate. These features are powered from redundant AC safety trains. This includes motor driven auxiliary feedwater pumps. Single train features, such as turbine driven auxiliary pumps, are not included in the list.

C TheCompletionTimeforRequiredActionJ[.1isintendedto allow the operator time to evaluate and repair any discovered inoperabilities. This Completion Time also allows for an exception to the normal " time zero" for beginning the allowed outage time " clock." In this Required Action the Completion Time only begins on discovery that both:

l a. All required offsite circuits are inoperable; and

b. A required feature is inoperable.

(continued)

I Vogtle Units 1 and 2 B 3.8-14 Revision No. O

y ...

AC Sources - Operating B 3.8.1 BASES j

C C ACTIONS g.1andE'.2 (continued)

If at any time during the existence of Conditiong (two offsite circuits inoperable) a required feature becomes !

inoperable, this Completi n Time begins to be tracked.

l l

According to Regulator Guide 1.93 (Ref. 6), operation may !

, continue in Condition y for a period that should not exceed l

24 hours2.777778e-4 days 0.00667 hours 3.968254e-5 weeks 9.132e-6 months . This level of degradation means that the offsite l electrical power system does not have the capability to !

effect a safe shutdown and to mitigate the effects of an L accident; however, the onsite AC sources have not been degraded. This level of degradation generally corresponds ,

to a total loss of the immediately accessible offsite power

! sources.

l Because of the normally high availability of the offsite l sources, this level of degradation may appear to be more l severe than other combinations of two AC sources inoperable l that involve one or more DGs inoperable. However, two factors tend to decrease the severity of this level of degradation:

a. The configuration of the redundant AC electrical power system that remains available is not susceptible to a

, single bus or switching failure; and

b. The time required to detect and restore an unavailable i

offsite power source is generally much less than that required to detect and restore an unavailable onsite l AC source.

With both of the required offsite circuits inoperable, sufficient onsite AC sources are available to maintain the l unit in a safe shutdown condition in the event of a DBA or l transient. In fact, a simultaneous loss of offsite AC sources, a LOCA, and a worst case single failure were l l postulated as a part of the design basis in the safety analysis. Thus, the 24 hour2.777778e-4 days 0.00667 hours 3.968254e-5 weeks 9.132e-6 months Completion Time provides a period of time to effect restoration of one of the offsite circuits commensurate with the importance of maintaining an l AC electrical power system capable of meeting its design criteria.

4 (continued)

?

Vogtle Units 1 and 2 B 3.8-15 Revision No. 0

.. . .f AC Sources - Operating 8 3.8.1 l BASES c c>

ACTIONS g.1andf.2 (continued)

According to Reference 6, with the available offsite AC l l sources, two less than required by the LCO, operation may 1 l continue for 24 hours2.777778e-4 days 0.00667 hours 3.968254e-5 weeks 9.132e-6 months . If two offsite sources are restored

! within 24 hours2.777778e-4 days 0.00667 hours 3.968254e-5 weeks 9.132e-6 months , unrestricted operation may continue. If only one offsite source is restored within 24 hours2.777778e-4 days 0.00667 hours 3.968254e-5 weeks 9.132e-6 months , power operation continues in accordance with Condition A. i O M

/1and/2 g l Pursuant to LC0 3.0. the Distribution System ACTIONS would l l

not be entered even ,

all AC sources to it were inoperable, '

l resulting in de-ener 'zation. Therefore, the Required Actions of Condition are modified by a Note to indicate that when Condition is entered with no AC source to one or ;

more trains, the Conditions and Required Actions for )

LC0 3.8.9, " Distribution Systems - Operating," must be '

immediately entered. This allows Condition to provide requirements for the loss of one offsite ci uit and one DG, l without regard to whether a train is de-ene gized.

l ions for a LC03.8.9providestheappropriaterestric}g de-energized train.

l According to Regulatory Guide 1.93 (Ref. 6), operation may continue in Condition / for a period that should not exceed i 12 hours1.388889e-4 days 0.00333 hours 1.984127e-5 weeks 4.566e-6 months .

1 D G l

In Condition f, in ividual redundancy is lost in both the offsite electrical power system and the onsite AC electrical power system. Since power system redundancy is provided by two diverse source s of power, however, the reliability of the power systems that in Condition in_(this p loss ofCondition may appear both required offsitehigher than circuits). This difference in reliability is offset by the l susceptibility of this power system configuration to a l single bus or switching failure. The 12 hour1.388889e-4 days 0.00333 hours 1.984127e-5 weeks 4.566e-6 months Completion Time takes into account the capacity and capability of the remaining AC sources, a reasonable time for repairs, and the low probability of a DBA occurring during this period.

(continued) l i

Vogtle Units 1 and 2 B 3.8-16 Revision No. O !

AC Sources - Operating B 3.8.1 i . .

BASES ACTIONS 1 With Train A and Train B DGs inoperable, there are no

remaining standby AC sources. Thus, with an assumed loss of l offsite electrical power, insufficient standby AC sources i are available to power the minimum required ESF functions.

Since the offsite electrical power system is the only source of AC power for this level of degradation, the risk associated with continued operation for a very short time could be less than that associated with an immediate controlled shutdown (the immediate shutdown could cause grid instability, which could result in a total loss of AC power). Since any inadvertent generator trip could also result in a total loss of offsite AC power, however, the time allowed for continued operation is severely restricted.

The intent here is to avoid the risk associated with an immediate controlled shutdown and to minimize the risk associated with this level of degradation.

According to Reference 6, with both DGs inoperable, operation may continue for a period that should not exceed 2 hours2.314815e-5 days 5.555556e-4 hours 3.306878e-6 weeks 7.61e-7 months .

F

,f.1 The sequencer (s) is an essential support system to both the offsite circuit and the DG associated with a given ESF bus.

Furthermore, the sequencer is on the primary success path for most major AC electrically powered safety systems powered from the associated ESF bus. The sequencers are required to provide the system response to both an SI signal and a loss of or degraded ESF bus voltage signal.

Therefore, loss of an ESF bus sequencer affects every major ESF system in the train. The 12 hour1.388889e-4 days 0.00333 hours 1.984127e-5 weeks 4.566e-6 months Completion Time provides a period of time to correct the problem commensurate with the importance of maintaining sequencer OPERABILITY. This time period also ensures that the probability of an accident (requiring sequencer OPERABILITY) occurring during periods when the sequencer is inoperable is minimal.

(continued) l Vogtle Units 1 and 2 B 3.8-17 Revision No. 0 1

9 AC Sources - Operating

' B 3.8.1 l BASES

! g g ACTIONS X 1 and Df2 (continued)

If the inoperable AC electric )ower sources or an automatic load sequencer cannot be restgred to OPERABLE status within the required Completion Time .v... " 3, ".?,

l 1 5.1, e. 3.5.2 n- et h .., [g - ";hepunit

.cdmust Ambe brought to a l

MODE in which the LC0 does not apply. To achieve this l status, the unit must be brought to at least MODE 3 within

6 hours6.944444e-5 days 0.00167 hours 9.920635e-6 weeks 2.283e-6 months and to MODE 5 within 36 hours4.166667e-4 days 0.01 hours 5.952381e-5 weeks 1.3698e-5 months . The allowed l Completion Times are reasonable, based on operating experience, to reach the required unit conditions from full power conditions in an orderly manner and without challenging plant systems.

N At 4 i

Condition / corresponds to a level of degradation in which all redundancy in the AC electrical power supplies has been i lost. At this severely degraded level, any further losses in the AC electrical power system will cause a loss of j function. Therefore, no additional time is justified for l continued operation. The unit is required by LC0 3.0.3 to commence a controlled shutdown.

l i SURVEILLANCE The AC sources are designed to permit inspection and testing REQUIREMENTS of all important areas and features, especially those that have a standby function, in accordance with 10 CFR 50, Appendix A, GDC 18 (Ref. 8). Periodic component tests are

! supplemented by extensive functional tests during refueling l outages (under simulated accident conditions). The SRs for

! demonstrating the OPERABILITY of the DGs are in accordance with the recommendations of Regulatory Guide 1.9 (Ref. 3),

Regulatory Guide 1.108 (Ref. 9), and Regulatory Guide 1.137 j (Ref. 10), as addressed in the FSAR.

Where the SRs discussed herein specify voltage and frequency tolerances, the following is applicable. The minimum steady state output voltage of 3750 V is 90% of the nominal 4160 V output voltage. This value, which is specified in ANSI C84.1 (Ref. 11), allows for voltage drop to the

! terminals of 4000 V motors whose minimum operating voltage is specified as 90% or 3600 V. It also allows for voltage (continued)

Vogtle Units 1 and 2 B 3.8-18 Revision No. O

., -1 l R: porting R:quirements 5.6 i

)

l 5.6 Reporting Requirements (continued) ..

5.6.5 Core Operatino Limits Report (COLR)

a. Core operating limits shall be established prior to each reload cycle, or prior to any remaining portion of a reload

cycle, and shall be documented in the COLR for the following

LCO 3.1.1 " SHUTDOWN MARGIN" l

LC0 3.1.3 " Moderator Temperature Coefficient" LC0 3.1.5 " Shutdown Bank Insertion Limits" LC0 3.1.6 " Control Bank Insertion Limits" LCO 3.2.1 " Heat Flux Hot Channel Factor" LC0 3.2.2 " Nuclear Enthalpy Rise Hot Channel Factor" '

i LCO 3.2.3 " Axial Flux Difference" "

LCD 3 9. I hon Concenfrafios

b. The analytical methods used to determine the core operating l limits shall be those previously reviewed and approved by l the NRC, specifically those described in the following documents:

WCAP-9272-P-A, " WESTINGHOUSE RELOAD SAFETY EVALUATION l METHODOLOGY," July 1985(HProprietary). (Methodology for Moderator Temperature Coefficient, Shutdown Bank Insertion l Limit, Control Bank Insertion Limits, and Nuclear Enthalpy )

Rise Hot Channel Factor.)

i WCAP-10216-P-A, Revision IA, " RELAXATION OF CONSTANT AXIAL 0FFSET CONTROL FQ SURVEILLANCE TECHNICAL SPECIFICATION " .

I February,1994 (H Proprietary). (Methodology for Axial Flux !

Difference (Relaxed Axial Offset Control) and Heat Flux Hot l Channel Factor (W(Z) surveillance requirements for F, '

Methodology).) ;

WCAP-10266-P-A, Revision 2, "The 1981 Version of the Westinghouse ECCS Evaluation Model Using the BASH Code,"

March 1987.

c. li i

The applicable core operating limits (e.mits g., fuelshall be determined thermal such that all mechanical limits, I core thermal hydraulic limits, Emergency Core Cooling l Systems (ECCS) limits, nuclear limits such as SDM, transient analysis limits, and accident analysis limits) of the safety analysis are met.

i (continued) a )

Vogtle Units 1 and 2 5.0-30 Amendment No. 96 Unit 1 Amendment No. 74 Unit 2

ML20117N585

Text

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