Text

Proposed Tech Specs LCOs 3.8.1,3.8.4 & 3.8.7 Re Ac Sources - Operating,Dc Sources - Operating & Inverters - Operating, Respectively
	ML20059B626
Person / Time
Site:	05200001
Issue date:	10/25/1993
From:	; GENERAL ELECTRIC CO.
To:	;
Shared Package
ML20059B624	List: ML20059B620; ML20059B626;
References
	NUDOCS 9310290033
	Download: ML20059B626 (79)
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AC Sources-0perating 3.8.1 3.8 ELECTRICAL POWER SYSTEMS 3.8.1 AC - Sources - Operating LC0 3.8.1 The following AC electrical power sources shall be OPERABLE:

a.

Two qualified circuits between the offsite transmission network and the onsite Class IE AC Electric Power Distribution System; and P

b.

Three diesel generators (DGs).

4 APPLICABILITY:

MODES 1, 2, and 3.

l ACTIONS CONDITION REQUIRED ACTION COMPLETION TIME A.

One of two offsite AC A.1 Verify affected ESF 72 hours8.333333e-4 days 0.02 hours 1.190476e-4 weeks 2.7396e-5 months pov r sources to one bus is powered from ESF ous inoperable.

the other operable AND offsite AC circuit.

once per 8 hours9.259259e-5 days 0.00222 hours 1.322751e-5 weeks 3.044e-6 months thereafter AND A.2 Verify the CTG is 72 hours8.333333e-4 days 0.02 hours 1.190476e-4 weeks 2.7396e-5 months functional by r

verifying the CTG AND starts and achieves steady state voltage once per 7 days and frequency within thereafter 10 minutes.

AND A.3 Verify the CTG 72 hours8.333333e-4 days 0.02 hours 1.190476e-4 weeks 2.7396e-5 months circuit breakers are aligned to the AND affected ESF bus.

Once per 8 hours9.259259e-5 days 0.00222 hours 1.322751e-5 weeks 3.044e-6 months thereafter (continued)

ABWR TS 3.8-1 10/21/93 NkSoSSSbOh!$1 ~

A

AC Sources-Operating 3.8.1 ACTIONS (continued)

CONDITION REQUIRED ACTION COMPLETION TIME A.

(continued)

AND A.4 Restore inoperable 30 days offsite AC power to affected ESF bus.

B.

One required offsite B.1 Perform SR 3.8.1.1 1 hour1.157407e-5 days 2.777778e-4 hours 1.653439e-6 weeks 3.805e-7 months circuit inoperable.

for OPERABLE required offsite circuit.

AND Once per i

8 hours9.259259e-5 days 0.00222 hours 1.322751e-5 weeks 3.044e-6 months thereafter AND B.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 power available from power available an OPERABLE offsite from an circuit inoperable OPERABLE when the redundant offsite circuit required feature (s) to one division are inoperable.

concurrent with inoperability of redundant required feature (s)

AND B.3 Verify the combustion 72 hours8.333333e-4 days 0.02 hours 1.190476e-4 weeks 2.7396e-5 months turbine generator (CTG) is functional by verifying the CTG starts and achieves steady state voltage and frequency within 10 minutes.

AND (continued)

ABWR TS 3.8-2 10/21/93

AC Sources-0perating 3.8.1 ACTIONS (continued)

CONDITION REQUIRED ACTION COMPLETION TIME B.

(continued)

B.4 Verify the CTG 72 hours8.333333e-4 days 0.02 hours 1.190476e-4 weeks 2.7396e-5 months circuit breakers are capable of being AND aligned to each of' three 6.9 kV once per 8 essential AC buses.

hours thereafter AND B.5 Restore required 14 days offsite circuit to OPERABLE status.

AND 1 day frcm discovery of two divisions with no power available from an OPERABLE offsite circuit AND 15 days from discovery of failure to meet the LC0 (continued) 9 ABWR TS 3.8-3 10/21/93

AC Sources-Operating 3.8.1 ACTIONS (continued)

CONDITION REQUIRED ACTION COMPLETION TIME C.

NOTE---------

C.1 Perform SR 3.8.1.1 1 hour1.157407e-5 days 2.777778e-4 hours 1.653439e-6 weeks 3.805e-7 months Required Action C.3.1 for OPERABLE required or C.3.2 shall be offsite circuit (s).

AND completed if this Condition is entered.

Once per 8 hours9.259259e-5 days 0.00222 hours 1.322751e-5 weeks 3.044e-6 months thereafter One required DG inoperable.

AND C.2 Declare required 4 hours4.62963e-5 days 0.00111 hours 6.613757e-6 weeks 1.522e-6 months from feature (s), supported discovery of by the inoperable DG, Condition C inoperable when the concurrent with redundant required inoperability feature (s) are of redundant inoperable, required feature (s)

AND C.3.1 Determine OPERABLE 24 hours2.777778e-4 days 0.00667 hours 3.968254e-5 weeks 9.132e-6 months DG(s) are not inoperable due to common cause failure.

OE C.3.2 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(s).

AND C.4 Verify the combustion 72 hours8.333333e-4 days 0.02 hours 1.190476e-4 weeks 2.7396e-5 months l

turbine generator (CTG) is functional by verifying the CTG starts and achieves l

steady state voltage and frequency within 10 minutes.

AND (continued)

ABWR TS 3.8-4 10/21/93

1 AC Sources-Operating 3.8.1 ACTIONS (continued)

CONDITION REQUIRED ACTION COMPLETION TIME C.

(continued)

C.5 Verify the CTG 72 hours8.333333e-4 days 0.02 hours 1.190476e-4 weeks 2.7396e-5 months circuit breakers are aligned to the 6.9 kV 6@

essential AC bus associated with the once per 8 inoperable DG.

hours thereafter l

AND C.6 Restore required DG 14 days to OPERABLE status.

AND 15 days from discovery of failure to meet the LC0 D.

Two required offsite D.1 Declare required 12 hours1.388889e-4 days 0.00333 hours 1.984127e-5 weeks 4.566e-6 months from circuits inoperable.

feature (s) inoperable discovery of when the redundant Condition D required feature (s) concurrent with are inoperable.

inoperability l

of redundant required feature (s)

AND D.2 Restore one required 24 hour:,

offsite circuit to OPERABLE status.

(continued) l l

ABWR TS 3.8-5 10/21/93

i AC Sources-0perating 3.8.1 ACTIONS (continued)

CONDITION REQUIRED ACTION COMPLETION TIME E.

One required offsite

NOTE-------------

circuit inoperable.

Enter applicable Conditions j

and Required Actions of AND LC0 3.8.9, " Distribution

)

Systems-Operating," when One required DG Condition D is entered with inoperable, no required AC power source to one division.

]

E.1 Verify the combustion 2 hours2.314815e-5 days 5.555556e-4 hours 3.306878e-6 weeks 7.61e-7 months turbine generator (CTG) is functional by verifying the CTG starts and achieves steady state voltage and frequency within 10 minutes.

AND i

E.2 Verify the CTG 2 hour2.314815e-5 days 5.555556e-4 hours 3.306878e-6 weeks 7.61e-7 months s-circuit breakers are capable of being AND aligned to each of three 6.9 kV once per 8 essential AC buses, hours thereafter AND i

E.3.1 Restore required 24 hours2.777778e-4 days 0.00667 hours 3.968254e-5 weeks 9.132e-6 months offsite circuit to OPERABLE status.

E.3.2 Restore required DG 24 hours2.777778e-4 days 0.00667 hours 3.968254e-5 weeks 9.132e-6 months to OPERABLE status.

(continued)

ABWR TS 3.8-6 10/21/93 1

J l

AC Sources-Operating 3.8.1 j

ACTIONS (continued)

CONDITION REQUIRED ACTION COMPLETION TIME F.

Two required DGs F.1 Verify the combustion 2 hours2.314815e-5 days 5.555556e-4 hours 3.306878e-6 weeks 7.61e-7 months inoperable.

turbine generator (CTG) is functional by verifying the CTG starts and achieves steady state voltage and frequency within 10 minutes.

AND F.2 Verify the CTG 2 hours2.314815e-5 days 5.555556e-4 hours 3.306878e-6 weeks 7.61e-7 months circuit breakers are capable of being AND aligned to each of the 6.9 kV essential once per 8 AC buses associated hours with the inoperable thereafter DGs.

AND F.3 Restore one required 72 hours8.333333e-4 days 0.02 hours 1.190476e-4 weeks 2.7396e-5 months DG to OPERABLE status.

G.

Required Action and G.1 Be in MODE 3.

12 hours1.388889e-4 days 0.00333 hours 1.984127e-5 weeks 4.566e-6 months Associated Completion Time of Condition A, AND B, C, D, E or F not met.

G.2 Be in MODE 4.

36 hours4.166667e-4 days 0.01 hours 5.952381e-5 weeks 1.3698e-5 months H.

Three or more required H.1 Enter LC0 3.0.3.

Immediately AC sources inoperable.

I ABWR TS 3.8-7 10/21/93

'l AC Sources-Operating 3.8.1 i

SURVEILLANCE REQUIREMENTS SURVEILLANCE

_ FREQUENCY 1

SR 3.8.1.1 Verify correct breaker alignment and 7 days indicated power availability for each required offsite circuit.

SR 3.8.1.2

NOTES-------------------

1.

Performance of SR 3.8.1.7 satisfies this SR.

2.

All DG starts may be preceded by an engine prelube period and followed by a warmup period prior to loading.

3.

A modified DG start involving idling and gradual acceleration to synchronous speed may be used for this SR as recommended by the manufacturer.

When modified start procedures are not used, the time, voltage, and frequency J

tolerances of SR 3.8.1.7 must be met.

Verify each DG starts from standby conditions and achieves steady state As specified in voltage 2 6210 V and s 7590 V and frequency Table 3.8.1-1 2 58.8 Hz and s 61.2 Hz.

(continued)

ABWR TS 3.8-8 10/21/93

AC Sources-0perating 3.8.1 SURVEILLANCE REQUIREMENTS (continued)

SURVEILLANCE FREQUENCY l

SR 3.8.1.3

NOTES-------------------

1.

DG loadings may include gradual loading as recommended by the manufacturer.

j 2.

Momentary transients outside the load range do not invalidate this test.

j 3.

This Surveillance shall be conducted on only one DG at a time.

4.

This SR shall be preceded by, and j

immediately follow, without shutdown, i

a successful performance of SR 3.8.1.2 or SR 3.8.1.7.

Verify each DG is synchronized and loaded As specified in and operates for 2 60 minutes at a load Table 3.8.1-1 2 5000 kW and s [

] kW.

SR 3.8.1.4 Verify each day tank contains 2 [

] liters 31 days of fuel oil.

1 i

SR 3.8.1.5 Check for and remove accumulated water from 31 days each day tank.

SR 3.8.1.6 Verify the fuel oil transfer system 92 days operates to automatically transfer fuel oil from the storage tank to the day tank.

(continued)

ABWR TS 3.8-9 10/21/93

AC Sources-Operating 3.8.1 SURVEILLANCE REQUIREMENTS (continued)

SURVEILLANCE FREQUENCY SR 3.8.1.7

NOTE--------------------

All DG starts may be preceded by an engine prelube period.

Verify each DG starts from standby 184 days condition and achieves, in s 20 seconds, voltage 2 6210.V and s 7590 V and frequency 2 58.8 Hz and s 61.2 Hz.

SR 3.8.1.8

NOTES------------------

1.

This Surveillance shall not be performed in MODE 1 or 2.

2.

Credit may be taken for unplanned events that satisfy this SR.

Verify manual transfer of the 18 months

[ unit power supply] from the normal offsite circuit to each required alternate offsite circuit.

i (continued) i i

'1 ABWR TS 3.8-10 10/21/93

)

AC Sources-Operating 3.8.1 SURVEILLANCE REQUIREMENTS (continued)

SURVEILLANCE FREQUENCY SR 3.8.1.9

NOTES--------------------

1.

This Surveillance shall not be performed in MODE 1 or 2.

2.

Credit may be taken for unplanned events that satisfy this SR.

Verify each DG operating at a power factor 18 months s[

] rejects a load 2 540 kW for Division 1 and 2 1400 kW for Divisions 2 and 3, and:

a.

Following load rejection, the frequency is s [

] Hz; b.

Within 3 seconds following load rejection, the voltage is 2 6210 V and s 7590 V; and c.

Within 3 seconds following load rejection, the frequency is 2 58.8 Hz and s 61.2 Hz.

SR 3.8.1.10

NOTES--------------------

1.

This Surveillance shall not be performed in MODE 1 or 2.

2.

Credit may be taken for unplanned events that satisfy this SR.

Verify each DG operating at a power factor 18 months 5 0.9 does not trip and voltage is maintained s [

] V during.and following a load rejection of a load 2 [5000] V and s[

] kW.

(continued)

ABWR IS 3.8-11 10/21/93

AC Sources-Operating 3.8.1 SURVEILLANCE REQUIREMENTS (continued)

SURVEILLANCE FREQUENCY SR 3.8.1.11

NOTES-------------------

1.

All DG starts may be preceded by an engine prelube period.

r 2.

This Surveillance shall not be performed in MODE 1, 2, or 3.

3.

Credit may be taken for unplanned events that satisfy this SR.

~

Verify on an actual or simulated loss of 18 months offsite power signal:

a.

De-energization of emergency buses; b.

Load shedding from emergency buses; and c.

DG auto-starts from standby condition and:

1.

energizes permanently connected loads in s 20 seconds, 2.

sequentially energizes auto-connected shutdown loads, 3.

maintains steady state voltage 2 6210 V and s 7590 V, 4.

maintains steady state frequency 2 58.8 Hz and s 61.2 Hz, and 5.

supplies permanently connected and auto-connected shutdown loads for 2 5 minutes.

(continued)

ABWR TS 3.8-12 10/21/93

AC Sources-Operating 3.C.1 SURVEILLANCE REQUIREMENTS (continued)

SURVEILLANCE FREQUENCY SR 3.8.1.12

NOTES-------------------

1.

All DG starts may be preceded by an engine prelube period.

2.

This Surveillance shall not be performed in MODE 1 or 2.

3.

Credit may be taken for unplanned events that satisfy this SR.

Verify on an actual or simulated Emergency 18 months Core Cooling System (ECCS) initiation signal each DG auto-starts from standby condition and:

a.

In s 20 seconds after auto-start and during tests, achieves voltage 2 6210 V and s 7590 V; b.

In s 20 seconds after auto-start and during tests, achieves frequency 2 58.8 Hz and 5 61.2 Hz; c.

Operates for 2 5 minutes; d.

Permanently connected loads remain energized from the offsite power system; and Emergency loads are sequentially e.

energized from the offsite power system.

(continued)

ABWR TS 3.8-13 10/21/93

AC Sources-0perating 3.8.1 SURVEILLANCE REQUIREMENTS (continued)

SURVEILLANCE FREQUENCY SR 3.8.1.13

NOTES-------------------

1.

This Surveillance shall not oe performed in MODE 1, 2, or 3.

2.

Credit may be taken for unplanned events that satisfy this SR.

Verify each DG's automatic trips are 18 months bypassed on actual or simulated loss of voltage signal on the emergency bus concurrent with an actual or simulated ECCS initiation signal except:

a.

Engine overspeed; and b.

Generator differential current.

SR 3.8.1.14

NOTES-------------------

1.

Momentary transients outside the load and power factor ranges do not invalidate this test.

2.

This Surveillance shall not be performed in MODE 1 or 2.

3.

Credit may be taken for unplanned events that satisfy this SR.

Verify each DG operating at a power factor 18 months s 0.9, operates for 2 24 hour2.777778e-4 days 0.00667 hours 3.968254e-5 weeks 9.132e-6 months s:

a.

For 2 2 hours2.314815e-5 days 5.555556e-4 hours 3.306878e-6 weeks 7.61e-7 months loaded, 2 5225 kW and 5 5500 kW; and b.

For the remaining hours of the test loaded 2 5000 kW and s [

].

(continued)

ABWR TS 3.8-14 10/21/93

[-

AC Sources-Operating 3.8.1 SURVEILLANCE REQUIREMENTS (continued)

SURVEILLANCE FREQUENCY SR 3.8.1.15

NOTES-------------------

l.

This Surveillance shall be performed within 5 minutes of shutting down the DG cfter the DG has operated 2 2 hours2.314815e-5 days 5.555556e-4 hours 3.306878e-6 weeks 7.61e-7 months loaded 2 5225 kW and s 5500 kW.

Momentary transients outside of load range do not invalidate this test.

2.

All DG starts may be preceded by an engine prelube period.

Verify each DG starts and achieves, in 18 months s 20 seconds, voltage 2 6210 V and s 7590 V and frequency 2 58.8 Hz and s 61.2 Hz.

SR 3.8.1.16

NOTES-------------------

1.

This Surveillance shall not be performed in MODE 1, 2, or 3.

2.

Credit may be taken for unplanned events that satisfy this SR.

Verify each DG:

18 months a.

Synchronizes with offsite power source while loaded with emergency loads upon a simulated restoration of offsite power; b.

Transfers loads to offsite power source; and c.

Returns to ready-to-load operation.

(continued) j j

ABWR TS 3.8-15 10/21/93

AC Sources-Operating 3.8.1 SURVEILLANCE REQUIREMENTS '(continued)

SURVEILLANCE FREQUENCY SR 3.8.1.17

NOTES-------------------

1.

This Surveillance shall not be performed in MODE 1, 2, or 3.

2.

Credit may be taken for unplanned events that satisfy this SR.

Verify, with a DG operating in test mode 18 months and connected to its bus, an actual or simulated ECCS initiation signal overrides the test mode by:

a.

Returning DG to ready-to-load operation; and b.

Automatically energizing the emergency load from offsite power.

SR 3.8.1.18

NOTES-------------------

1.

This Surveillance shall not be performed in MODE 1, 2, or 3.

2.

Credit may be taken for unplanned events that satisfy this SR.

Verify interval between each sequenced load 18 months i

block is within i 10% of design interval i

for each load sequencer timer.

(continued)

ABWR TS 3.8-16 10/21/93

1 AC Sources-Operating i

3.8.1 SURVEILLANCE REQUIREMENTS (continued)

SURVEILLANCE FREQUENCY SR 3.8.1.19

NOTES-------------------

i 1.

All DG starts may be preceded by an engine prelube period.

2.

This Surveillance shall not be performed in MODE 1, 2, or 3.

3.

Credit may be taken for unplanned events that satisfy this SR.

.i Verify, on an actual or simulated loss of 18 months offsite power signal in conjunction with an actual or simulated ECCS initiation signal:

a.

De-energization of emergency buses; b.

Load shedding from emergency buses; and c.

DG auto-starts from standby condition and:

1.

energizes permanently connected loads in s 20 seconds, 2.

sequentially energizes auto-connected emergency loads, 3.

achieves steady state voltage 2 6210 V and s 7590 V, l

4.

achieves steady state frequency 2 58.8 Hz and s 61.2 Hz, and 5.

supplies permanently connected and auto-connected emergency loads for 2 5 minutes.

l (continued)

ABWR TS 3.8-17 10/21/93

AC Sources-Operating '

3.8.1 SURVEILLANCE REQUIREMENTS (continued)

SURVEILLANCE FREQUENCY j

SR 3.8.1.20

NOTE--------------------

All DG starts may be pre;eded by an engine prelube period.

Verify, when started simultaneously from 10 years during standby condition, each Division 1, 2, shutdown and 3 DG achieves, in s 20 seconds, voltage 2 6210 V and 5 7590 V and frequency 2 58.8 Hz and s 61.2 Hz.

1 f

i l

I ABWR TS 3.8-18 10/21/93

1 i

i AC Sources-Operating 3.8.1 1

Table 3.8.1-1 (page 1 of 1)

Diesel Generator Test Schedule NUMBER OF FAILURES IN LAST 25 VALID-TESTS (a)

FREQUENCY s3 31 days 24 7 days (b) (but 2 24 hours2.777778e-4 days 0.00667 hours 3.968254e-5 weeks 9.132e-6 months ) i (a)

Criteria for determining number of failures and valid tests shall be in accordance with Regulatory Position C.2.1 of Regulatory Guide 1.9, Revision 3, where the number of tests and failures is determined on a per DG basis.

(b)

This test frequency shall be maintained until seven consecutive failure free starts from standby conditions and load and run tests have been performed. This is consistent with Regulatory Position [

], of Regulatory Guide 1.9, Revision 3.

If, subsequent to the 7 failure free tests,1 or more additional failures occur such that there are again 4 or more failures in the last 25 tests, the testing interval shall again be reduced as noted above and maintained until 7 consecutive failure free tests have been performed.

I 4

ABWR TS 3.8-19 10/21/93 l

AC Sources-Operating B 3.8.1 B 3.8 ELECTRICAL PCWER SYSTEMS B 3.8.1 AC Sources-Operating BASES BACKGROUND The unit Class IE AC Electrical Power Distribution System AC sources consist of the offsite power sources (normal preferred and alternate preferred) and the onsite standby power sources (Division I diesel generator (DG), Division II DG, and Division III DG). As required by 10 CFR 50, Appendix A, GDC 17 (Ref.1), the design of the AC electrical power system provides independence and. redundancy to ensure an available source of power to the Engineered Safety Feature (ESF) systems.

The Class lE AC distribution system supplies electrical power to three divisional load groups, with each division powered by an independent Class IE 6.9 kV ESF bus (refer to LCO 3.8.9, " Distribution Systems-Operating").

Each ESF bus has two separate ar.d independent preferred (offsite) sources of power and a dedicated onsite DG.

Each ESF bus is also connectable to a combustion turbine generator (CTG).

The ESF systems of any two of the three divisions provide for the minimum safety functions necessary to shut down the unit i

and maintain it in a safe shutdown condition.

Offsite power is supplied to each of the 6.9 kV ESF buses from the transmission network via two electrically ~and physically separated circuits.

Ihlidditi6hi@ffsite ~~

m ayi behuphl i ed it o%nf}8ns7ES FE bu sifFom7 t he ! CTG i

~

a l.imi ted ; durat i on)? when.i thelESFl bustis? be ing i fed !framJtfis reseriIeisuxiliaryetransformerJwhilef thesunitsauxiliary transformeras'sociated;withithetESFibusfis?outMfdebvTdel Thes e ~6f fs'i te" AC ^&l ecti ifal')6w3 F"Ei Fcdi t~s"YFelisished"ind located so as to minimize to the extent practicable the likelihood of their simultaneous failure under operating and postulated accident and environmental conditions. A detailed description of the offsite power system and circuits to the onsite Class lE ESF buses is found in SSAR, Chapter 8 (Ref. 2).

An offsite circuit consists of all breakers, transformers, switches, interrupting devices, cabling, controls, and control power supplies required to transmit power from the offsite transmission network to the onsite Class lE ESF bus (es). Certain required plant loads are returned to (continued)

ABWR TS B 3.8-1 10/21/93

AC Sources-Operating B 3.8.1 BASES BACKGROUND (continued) service in a predetermined sequence in order to prevent overloading the transformer supplying offsite power to the onsite Class IE Distribution System.

Initiating signals (i.e., load shedding and buses-ready-to-load) for returning certain plant loads to service are generated by the control system for the electrical power distribution system.

Individual timers for each major load are reset and started by their electrical power distribution system signals 15d/"6i!

LOCA[s;ijdals. After the initiating signals are receividT all automatic and permanently connected loads needed to recover the unit or maintain it in a safe condition are returned to service in a preset sequence via timer delays on each load.

The onsite standby power source for each 6.9 kV ESF bus is a dedicated DG. A DG starts automatically on loss of coolant accident (LOCA) signal (i.e., signal generated from low reactor water level and high drywell pressure that are arranged in two-out-of four logic combinations bus undervoltage signal (refer to LC0 3Y371?DO) or on an ESF ES$

Actuhti61iInstrumentation"). -le-add 44ssi thTCTC'prevides ankt48 ' independent source Of AC power that-ean be manuaMy aMsned to any4E-F bus.

The CTC provides On extrc level cf redundancy that can-be utilized under cert-ain conditions.

Inf addit'iodp6Gedelin bsZsOppiie'dTtifshifoMESSff6hi3his i

CTG [( for) all i mi,ted (durati on;);whenNDG li sJf nop e rabl ej In the event of a loss of preferred power, the ESF electrical loads are automatically connected to the DGs in sufficient time to provide for safe reactor shutdown and to mitigate the consequences of a Design Basis Accident (DBA) such as a LOCA.

Ratings for DGs satisfy the requirements of Regulatory Guide 1.9 (Ref. 3). The continuous service rating for each DG is 5000 kW, with 10% overload permissible for up to 2 hou..; in any 24 hour2.777778e-4 days 0.00667 hours 3.968254e-5 weeks 9.132e-6 months period.

APPLICABLE The initial conditions of DBA and transient analyses in the SAFETY ANALYSES SSAR, Chapter 6 (Ref. 4) and Chapter 15 (Ref. 5), assume ESF systems are OPERABLE.

The AC electrical power sources are designed to provide sufficient capacity, capability, redundancy, and reliability to ensure the availability of (continued)

ABWR TS B 3.8-2 10/21/93

AC Sources-Operating B 3.8.1 i

BASES APPLICABLE necessary power to ESF systems so that the fuel, Reactor SAFETY ANALYSES Coolant System (RCS), and containment design limits are not exceeded.

These limits are discussed in more detail in the Bases for Section 3.2, Power Distribution Limits; Section 3.4, Reactor Coolant System (RCS); and Section 3.6, Containment Systems.

The OPERABILITY of the AC electrical power sources (not including the CTG) is consistent with the initial assumptions of the accident analyses and is based upon meeting the design basis of the unit. This includes maintaining the onsite or offsite AC sources OPERABLE during accident conditions in the event of:

a.

An assumed loss of all offsite power or all onsite AC power; and b.

A worst case single failure.

AC sources satisfy the requirements of Criterion 3 of the NRC Policy Statement.

16 Tiddi ti bn Zt hs 70TGimiyf4s?s~6 bit'i tGisEf6FithiNsF6iid (delayf access)soffsitsi;sodrce5to?anyloh6TESEsblisiwheh %hi fi rst2 ( imed i a te f a cce s s ) fo f f s i t ei s ouFce%i s a 0xil i ary ltrib s foEm'eWWh il s7 thsVUni ttisuill i sffVtf ans farmsf hs s oc i ated !wi t hith e ! ES n tf0Ei s 4u tTo fMe hli ce MThis CTGims al so;4 bsin s edi toj su bs t i tUte f (f6dalfl i mi tedit i me)floEAh~~

i n ope ra bl e1 DG W Wi t hi thi sis ub s t i t6 ti b6 fdh's? AC Tel sc'tribil; poweM soa rdssisfsfde signedit63rovidusu f fi slest@ubsei t ca pabill1 ti Medurid ancydand Wbl i abil i tibio) en s upef the^ ~if svallability)?C6olant1SystemofinecessarffprnierstpESEs s

b i i liraits:jreina.tlexcee;dE.d C '(RCS)~A~and;9s fuelfRsactor

""~~~~'~~"p~centainmentidsfi ri

~~

LC0 Two qualified offsite circuits between the offsite transmission network and the onsite Class IE Distribution System that consists of three separate and independent divisions (Divisions I, II, and III) each backed by its own dedicated and independent DG, ensure availability of the required power to shut down the reactor and maintain it in a safe shutdown condition after an anticipated operational occurrence (A00) or a postulated DBA. h-add 4tien, the CTG (continued)

ABWR TS B 3.8-3 10/21/93

i AC Sources-Operating B 3.8.1 BASES LCO (continued) may-be-utM4ited as a temporary-repheement-fem.4mufred oHMte-or ensite-sources _tc any-one-ESF-bus-undeggrta4e eendM4 ens-In addit'iont the._ CTG.may; be' utilliediasta temporary substitution for thefseconds(delayed 1 access)esis) qual i fled:-offs ite; circuit;when7 the? fi rst l(immediate(ac qualified.offsite circuitlto::::anytone1 ESF?: bus 1(immediate '

access)ioffsite source Lisifrom;the? reserve auxiliary stid transformer while thelunit:?auxiliaryktrnsformeFlassodi with the ESFiblisLisioutSof;Eservice. JWith' this itenipor5ry' substitution, theJtwo; qualified?offsiteicircuitsLbetsseniths offsite transmission-' network 1and-theron' site C1 ass 51E Distribution? System that consistshoffthreeiseparate75Iid independent: divi's ions f (Divisions 11 kII',f and.f III)feabhiba~dked byitionnidedicatedMndsindependentiDG,yalsoiensurel

~

availability of1the4 the: required power toishutdown;(the reactor and maintainlit:in'a safe' condition:tafter an anticipat_ed ~ operational.~ occurrence 1(A00)Johaj post' lstid u

DBA.

Qualified offsite circuits are the normal and alternate preferred power circuits that are described in the SSAR and are part of the licensing basis for the unit inLaddition, the temporary substitution'of the' CTG is desdribedsinlthe SSAR and is part of the. licensing basis.for the:uniti-Each offsite circuit must be capable of maintaining rated frequency and voltage, and accepting required loads within the assumed load sequence intervals during an accident, while connected to the ESF buses. The normal preferred circuit consists of the switching station breaker to the main transformer, the generator breaker, the disconnect links to the unit auxiliary transformers, and the circuit path from the offsite transmission network to all of the 6.9 kV ESF buses including feeder breakers at the 6.9 kV ESF buses.

The alternate preferred circuit consists of the switching station breaker to the reserve auxiliary transformer and the circuit path from the offsite transmission network to all of the 6.9 kV ESF buses including feeder breakers at the 6.9 kV ESF buses.

Each DG must be capable of starting, accelerating to rated speed and voltage, and connecting to its respective ESF bus on detection of bus undervoltage. This sequence must be accomplished within 20 seconds.

Each DG must also be capable of accepting required loads within the assumed (continued)

ABWR TS B 3.8-4 10/21/93

1 AC Sources-Operating B 3.8.1 BASES LC0 (continued) loading sequence intervals, and must continue to operate until offsite power can be restored to the ESF buses. These capabilities are required to be met from a variety of initial conditions such as DG in standby with engine hot, DG in standby with engine at ambient conditions, and DG operating in parallel test mode.

Ths!CTGMhsFUsediasitsnipbraFilidif5Vif0fsifdNihs75^essiid

~ ffsitetsourcetor;for$aninoperable!DGitdianiloheXESF&dsf o

iesdidd inus ts beicapabl e16gstar;ti ng hiccsl efat i nglito ssted f s;doWsf u

Vol t ag eNand) o fs be i ng / manu al lisco n fi g u rsd { tbjk6Vi de toothesESFVbustiThisise'quencelmustEbs? accomplished {Within requiredtidsdsNlo.mustj;befcapablesoffmai'tain 10imindt'est BThe CTGimustislsoTb icapabletbfsaiiceptiri n

frequenc9f andiv 1t'ag'epandisccepting]feguitedGoad5;Jyhid connectedito?the ESF?busj Proper sequencing of loads is a required function for both DG and offsite circuit OPERABILITY.

The AC sources are separate and independent.

For the DG AC sources, the separation and independence are complete.

For the offsite AC sources (including the CTG as an offsite source), the separation and independence are to the extent practicable. For the offsite (including the CTG) to DG AC sources, the separation and independence are to the extent practicable.

Offsite circuit OPERABILITY includes the normal offsite source supplying two of three AC divisions and the alternate offsite source supplying the third AC division. Other configurations make an offsite circuit inoperable.

The AC sources are required to be OPERABLE in MODES 1, 2, and 3 to ensure that:

a.

Acceptable fuel design limits and reactor coolant 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.

(continued)

ABWR TS B 3.8-5 10/21/93

AC Sources-Operating B 3.8.1 BASES LC0 (continued)

AC power requirements for MODES 4 and 5 are covered in LC0 3.8.2, "AC Sources-Refueling", and LC0 3.8.11, "AC Sources-Shutdown (Low Water Level)."

ACTIONS A.1. A.2. A 3, and A.4 If Condition A is entered, Required Action A.4 allows 30 days to restore the inoperable offsite power source to one ESF bus to OPERABLE status provided:

a.

The ESF bus with its associated unit auxiliary transformer inoperable is verified to be energized from the offsite transmission network through the reserve auxiliary transformer initially within 72 hours8.333333e-4 days 0.02 hours 1.190476e-4 weeks 2.7396e-5 months , and once per 8 hours9.259259e-5 days 0.00222 hours 1.322751e-5 weeks 3.044e-6 months thereafter, b.

The CTG is verified functional through testing within 72 hours8.333333e-4 days 0.02 hours 1.190476e-4 weeks 2.7396e-5 months and once per 7 days thereafter, c.

The CTG is verified to be aligned with the ESF bus that has its associated unit auxiliary transformer inoperable within 72 hours8.333333e-4 days 0.02 hours 1.190476e-4 weeks 2.7396e-5 months , and once per 8 hours9.259259e-5 days 0.00222 hours 1.322751e-5 weeks 3.044e-6 months thereafter.

The 30 day Completion Time is reasonable because it accounts for the reliability and convenience of the CTG.

Since the CTG can be aligned as a temporary backup offsite source, there are sufficient offsite sources available if Required Actions A.2 and A.3 are completed. The LC0 is satisfied at this point.

However, given the primary function of the CTG as the alternate AC power source during the station blackout event and a a standby non-safety related power source located onsite to energize non-safety related plant investment protection loads, the Completion Time has been limited to 30 days.

If the CTG cannot be made available to function as a l

temporary backup offsite circuit within 72 hours8.333333e-4 days 0.02 hours 1.190476e-4 weeks 2.7396e-5 months , the configuration of the AC sources is described in Regulatory j

(continued)

ABWR TS B 3.8-6 10/21/93

AC Sources-Operating B 3.8.1 BASES ACTIONS A.I. A.2. A.3 and A.4 (continued)

(continued)

Guide 1.93 (Ref. 6), which states that operation in the applicable modes may continue as described by Condition A for a period that should not exceed 72 hours8.333333e-4 days 0.02 hours 1.190476e-4 weeks 2.7396e-5 months .

Therefore, if Required Actions A.2 and A.3 cannot be completed within 72 hours8.333333e-4 days 0.02 hours 1.190476e-4 weeks 2.7396e-5 months of entering Condition A, then Required Actions G.1 and G.2 must be followed.

Upon restoring the offsite circuit to OPERABLE status, the LC0 is met, Conditions A and F are exited, and operation may continue.

Should the CTG no longer be functional or capable of being aligned to the ESF bus subsequent to the 72-hour period following initial entry into Condition A, Condition F again applies and Required Actions G.1 and G.2 must be followed.

Anytime the 8-hours Completion Time of Required Action A.3 is not met during this extension period, Condition F must be entered.

Condition F can then only be exited by restoring the offsite circuit to OPERABLE status.

B.1 To ensure a highly reliable power source remains, it is necessary to verify the availability of the remaining required offsite circuits on a more frequent basis.

Since the Required Action only specifies " perform," a failure of SR 3.8.1.1 acceptance criteria does not result in the Required Action not met. However, if a second required circuit fails SR 3.8.1.1, the second offsite circuit is inoperable, and Condition D, for two offsite circuits inoperable, is entered.

B.2 Required Action B.2, which only applies if the division cannot be powered from an offsite source, is intended to provide assurance that an event with a coincident single failure of the associated DG does not result in a complete loss of safety function of critical systems. These features are designed with redundant safety related divisions.

Redundant required features failures consist of inoperable features associated with a division redundant to the division that has no offsite power.

(continued)

ABWR TS B 3.8-7 10/21/93

AC Sources-Operating o 3.8.1 BASES ACTIONS JL2 (continued)

(continued)

The Completion Time for Required Action B.2 is intended to allow time for the operator 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 division has no offsite power supplying its loads; and b.

A required feature on the other division is inoperable.

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

Discovering no offsite power to one division of the onsite Class IE Power Distribution System coincident with one or more inoperable required support or supported features, or both, that are associated with the other division 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 the unit is subjected to transients associated with shutdown.

The remaining OPERABLE offsite circuit and DGs are adequate to supply electrical power to the onsite Class IE Distribution System.

Thus, on a component basis, single failure protection may have been lost for the required i

feature's function; however, function is not lost.

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 redundant counterpart to the inoperable required feature. Addi.tionally, 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 i

remaining AC sources, a reasonable time for repairs, and the i

low probability of a.DBA occurring during this period.

(continued)

ABWR TS B 3.8-8 10/21/93

AC Sources-0perating B 3.8.1 BASES ACTIONS B.3. B.4 and B.5 (continued)

If Condition B is entered, Required Action B.5 allows 14 days to restore the inoperable offsite circuit to OPERABLE status, provided the combustion turbine generator (CTG) is verified functional through testing within 72 hours8.333333e-4 days 0.02 hours 1.190476e-4 weeks 2.7396e-5 months and its capabilityofbeingalignedtoinjT6Nthethree6.9kV essential AC buses is verified,"ini'tiilly within 72 hours8.333333e-4 days 0.02 hours 1.190476e-4 weeks 2.7396e-5 months , and once per 8 hours9.259259e-5 days 0.00222 hours 1.322751e-5 weeks 3.044e-6 months thereafter. This 14-day Completion Time is reasonable because it accounts for the reliability and convenience of the CTG. Since the CTG can be aligned as a temporary backup offsite source, there are sufficient offsite sources available if Required Actions B.3 and B.4 are completed.

The LC0 is not completely satisfied at this point, but the AC electrical power system is verified to be sufficiently reliable to allow for the 14-day Completion Time of Required Action A.S.

The 14-day Completion Time is also reasonable because the capabilities of the reinaining AC sources are adequate for this time period, and because of the low probability of a DBA occurring during this time period.

See the discussion for Required Action C.6 for additional justification of this Completion Time.

If the CTG cannot be made available to function as a temporary backup offsite circuit within 72 hours8.333333e-4 days 0.02 hours 1.190476e-4 weeks 2.7396e-5 months , the configuration of the AC sources is as described in Regulatory Guide 1.93 (Ref. 6), which states that operation in the applicable modes may continue as described by Condition B for a period that should not exceed 72 hours8.333333e-4 days 0.02 hours 1.190476e-4 weeks 2.7396e-5 months .

Therefore, if Required Actions B.3 and B.4 cannot be completed within 72 hours8.333333e-4 days 0.02 hours 1.190476e-4 weeks 2.7396e-5 months of entering Condition B, then Required Actions G.1 and G.2 must be followed.

Upon restoring the offsite circuit to OPERABLE status, the LCO is met, Conditions B and G are exited, and operhtion may continue.

I Should the CTG no longer be functional or capable of being aligned to a 6.9 kV AC ESF bus subsequent to the 72-hour

]

period following initial entry into Condition B, Condition G again applies and Required Actions G.1 and G.2 must be followed. Anytime the 8-hour Completion Time of Required Action B.4 is not met during this extension period, Condition G must be entered.

Condition G can then only be-exited by restoring the offsite circuit to OPERABLE status.

(continued)

ABWR TS B 3.8-9 10/21/93

AC Sources-0perating B 3.8.1 BASES ACTIONS B.3. B.4. and B.5 (continued)

(continued)

The CTG is considered functional when the requirements of Section 9.5.13.19 of the SSAR are satisfied and the CTG is verified to start hem-nandby-comRt4ons-and achieves steady state voltage 2 6210 V and s 7590 V, and frequency 2 58.8 Hz and s 61.2 Hz within 2 minutes.

The 14-day Completion Time of Required Action B.5 assumes sufficient offsite power remains to power the minimum loads needed to respond to analyzed events.

It also assumes that the CTG may be utilized if needed.

Should two divisions be affected, the 1-day Completion Time of Required Action B.5 is conservative with respect to the Regulatory Guide assumptions supporting a 1 day Completion Time for both offsite circuits inoperable (addressed by Condition D).

With only one offsite circuit, the reliability of the offsite system is degraded, and the potential for a loss of offsite power is increased, with attendant potential for a challenge to the plant safety systems.

In Condition B, however, the remaining OPERABLE offsite circuit, DGs, and the CTG are adequate to supply electrical power to the onsite Class lE distribution system.

The 14-day Completion Time takes into account the capacity and capability of the remaining AC sources, reasonable time for repairs, and the low probability of a DBA occurring during this period.

The third Completion Time for Required Action B.5 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 Condition B is entered while, for instance, a DG is inoperable and that DG is subsequently returned to i

OPERABLE status, the LCO may already have been not met for up to 14 days.

This situation could lead to a total of 28 days, since initial failure to meet the LCO, to restore the offsite circuit. At this time, a DG could again become inoperable, the circuit restored to OPERABLE status, and an additional 14 days (for a total of 42 days) allowed prior to complete restoration of the LCO.

The 15-day Completion Time provides a limit on the time allowed in a specified Condition after discovery of failure to meet the LCO.

(continued)

ABWR TS B 3.8-10 10/21/93

AC Sources-Operating B 3.8.1 BASES ACTIONS B.3. B.4. and B.5 (continued)

(continued)

This limit is considered reasonable for situations in which Conditions B and C are entered concurrently. The "MQ" connector between the 14-day and 15-day Ccmpletion Times means that both Completion Times apply simultaneously, and the more restrictive must be met.

As in Required Action B.2, the Completion Time allows for an exception to the normal " time zero" for beginning the allowed outage time " clock." This exception results in l

establishing the " time zero" at the time the LC0 was initially not met, instead of at the time that Condition B i

was entered.

L1 To ensure a highly reliable power source remains, it is necessary to verify the availability of the remaining required offsite circuit on a 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 j

Action being not met. However, if a circuit fails to pass SR 3.8.1.1, it is inoperable.

Upon offsite circuit I

inoperability, additional Conditions must then be entered.

C.2 Required Action C.2 is intended to provide assurance that a j

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 divisions (i.e., single division systems are not included).

Redundant required features failures consist of inoperable features associated with a division redundant to the division that has an inoperable DG.

The Completion Time 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."

(continued)

ABWR TS B 3.8-11 70/21/93

AC Sources-Operating B 3.8.1 BASES ACTIONS C.2 (continued)

(continued)

In this Required Action, the Completion Time only begins on discovery that both:

a.

An inoperable DG exists; and b.

A required feature on the other division is inoperable.

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

Discovering one required DG inoperable coincident with one or more required support or supported features, or both, that are associated with the OPERABLE DGs, 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.

The remaining OPERABLE DGs and offsite circuits are adequate to supply electrical power to the onsite Class 1E Distribution System.

Thus, on a component basis, single failure protection for the required feature's function may have been lost; however, function has not been lost.

The 4 hour4.62963e-5 days 0.00111 hours 6.613757e-6 weeks 1.522e-6 months Completion Time takes into account the component 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, reasonable time for repairs, and low probability of a DBA occurring during this period.

C.3.1 and C.3.2 The Note in Condition C requires that Required Action C.3.1 or C.3.2 must be completed if Condition C is entered. The intent is that all DG inoperabilities must be investigated for common cause failures regardless of how long the DG inoperability pers'sts.

Required Action C.3.1 provides an allowance to avoid unnecessary testing of OPERABLE DGs.

If it can be

(.antinued)

ABWR TS B 3.8-12 10/21/93

AC Sources-0perating B 3.8.1 BASES ACTIONS C.3.1 and C.3.2 (continued)

(continued) 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 other DGs, the other DGs are declared inoperable upon discovery, and Condition F of LC0 3.8.1 is entered.

Once the failure is repaired, and the common cause failure no longer exists, Required Action C.3.1 is satisfied.

If the cause of the initial inoperable DG cannot be confirmed not to exist on the remaining DG(s), performance of SR 3.8.1.2 suffices to provide assurance of continued OPERABILITY of those DGs.

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 time to confirm that the OPERABLE DGs are not affected by the same problem as the inoperable DG.

C.4. C.S. and C.6 If Condition C is entered, Required Action C.6 allows 14 days to restore the inoperable DG to OPERABLE status provided the CTG is verified functional through testing within 72 hours8.333333e-4 days 0.02 hours 1.190476e-4 weeks 2.7396e-5 months , and its circuit breakers are verified to be aligned to the affected 6.9 kV essential AC bus initially within 72 hours8.333333e-4 days 0.02 hours 1.190476e-4 weeks 2.7396e-5 months and once per 8 hours9.259259e-5 days 0.00222 hours 1.322751e-5 weeks 3.044e-6 months thereafter.

This 14-day Completion Time is reasonable because of the reliability and convenience of the CTG, the low probability of a DBA occurring during this time period.

The CTG is considered functional when the requirements of Section 9.5.13.19 of the SSAR are satisfied and the CTG is verified to start from standby conditions and achieves steady state voltage 2 6210 V and s 7590 V, and frequency 2 58.8 Hz and s 61.2 Hz within 2 minutes.

If the CTG can not be made available to function as a temporary onsite divisional backup to preferred offsite power, the configuration of the AC sources is as described in Regulatory Guide 1.93 (Ref. 6), which states that operation may continue as described in Condition C for a period that should not exceed 72 hours8.333333e-4 days 0.02 hours 1.190476e-4 weeks 2.7396e-5 months .

Therefore, if Required Actions C.4 and C.5 cannot be completed within 72 hours8.333333e-4 days 0.02 hours 1.190476e-4 weeks 2.7396e-5 months of entering Condition B, then Required Actions G.1 and G.2 must be followed.

Upon restoring the inoperable DG to OPERABLE status, the LC0 is met, Conditions C and G are exited, and opera +1on may continue.

(continued)

ABWR TS B 3.8-13 10/21/93

AC Sources-0perating B 3.8.1 BASES ACTIONS C.4. C.5. and C.6 (continued)

(continued)

In Condition C, if the CTG is not functional, the remaining OPERABLE DGs and offsite circuits are adequate to supply electrical power to the onsite Class lE distribution system for 72 hours8.333333e-4 days 0.02 hours 1.190476e-4 weeks 2.7396e-5 months . The 72 hour8.333333e-4 days 0.02 hours 1.190476e-4 weeks 2.7396e-5 months Completion Time takes into account the capacity and capability of the remaining AC sources, reasonable time for repairs, and low probability of a DBA occurring during this period.

Should the CTG no longer be functional or capable of being aligned to a 6.9 kV essential AC bus subsequent to the 72-hour period following initial entry into Condition C, Condl tion G again applies and Required Actions G.1 and G.2 must be followed.

Anytime the 8-hour Completion Time of Required Action C.5 is not met during this extension period, Condition F must be entered.

Condition G can then only be exited by restoring the DG to OPERABLE status.

The once-per-8-hour Completion Time of Required Action C.5 is necessary to keep a check on the proper alignment of the CTG's circuit breakers and thus the capability of 1

supplying power from the CTG to the 6.9 kV essential AC bus associated with the inoperable DG.

The second Completion Time for Required Action C.6 establishes a 8-day 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 Condition C is entered while, for instance, an offsite circuit is inoperable and that circuit is subsequently restored OPERABLE, the LC0 may already have been not met for up to 7 days.

This situation could lead to a total of 14 days, since initial failure to meet the LCO, to restore the DG. At this time, an offsite circuit could again become inoperable, the DG restored OPERABLE, and an additional 7 days (for a total of 21 days) would be allowed prior to complete restoration of the LCO.

The 8-day Completion Time provides a limit on the time allowed in a specified condition after discnvery of failure to meet the LCO.

This limit is considered reasonable for situations in which Conditions B and C are entered concurrently.

The "AND" connector between the 7-day and 8-day Completion Times means that both Completion Times apply simultaneously, and the more restrictive must be met.

I (continued)

ABWR TS B 3.8-14 10/21/93

AC Sources-Operating B 3.8.1 BASES ACTIONS C.4. C.S. and C.f (continued)

(continued)

As in Required Action C.2, the 8-day Completion Time of Required Action C.5 allows for an exception to the normal

" time zero" for beginning the allowed outage time " clock."

This exception results in establishing the " time zero" at the time the LCO was initially not met, instead of the time Condition C was entered.

D.1 and D.2 Required Action D.1 addresses actions to be taken in the event of concurrent failure of redundant required features.

Required Action D.1 reduces the vulnerability to a loss of function.

The Completion Time for taking these actions is reduced to 12 hours1.388889e-4 days 0.00333 hours 1.984127e-5 weeks 4.566e-6 months from that allowed with only one division without offsite power (Required Action B.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 all three safety divisions 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 designed with redundant safety related divisions (i.e.,

single division systems are not included in the list).

Redundant required features failures consist of any of these features that are inoperable, because any inoperability is on a division redundant to a division with inoperable offsite circuits.

The Completion Time for Required Action D.1 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.

All required offsite circuits are inoperable; and b.

A required feature is inoperable.

If, at any time during the existence of this Condition (two offsite circuits inoperable), a required feature (continued)

ABWR TS B 3.8-15 10/21/93

AC Sources-Operating B 3.8.1 BASES ACTIONS D.1 and 0.2 (continued)

(continued) subsequently becomes inoperable, this Completion Time begins to be tracked.

According to Regulatory Guide 1.93 (Ref. 6), operation may continue in Condition D for a period that should not exceed 24 hours2.777778e-4 days 0.00667 hours 3.968254e-5 weeks 9.132e-6 months .

This level of degradation means that the offsite electrical power system does not have the capability to effect a safe shutdown and to mitigate the effects of an i

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.

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

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

With both of the required offsite circuits inoperable, sufficient onsite AC sources are available to maintain the unit in a safe shutdown condition in the event of a DBA or transient.

In fact, a simultanenus loss of offsite AC sources, a LOCA, and a worst case single failure were 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 AC electrical power system capable of_ meeting its design criteria.

According to Regulatory Guide 1.93 (Ref. 6), with the available offsite AC sources two less than required by the LCO, operation may continue for 24 hours2.777778e-4 days 0.00667 hours 3.968254e-5 weeks 9.132e-6 months . If two offsite

(

(continued) i ABWR TS B 3.8-16 10/21/93

-l AC Sources-Operating B 3.8.1 BASES ACTIONS D.1 and D.2 (continued) l (continued) 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 B.

The status of the CTG was not a consideration in establishing the appropriate Completion Times for Required Actions D.1 AND D.2.

E.1 and E.2 Pursuant to LCO 3.0.6, the Distribution System ACTIONS would not be entered even if all AC sources to it were inoperable, resulting in de-energization.

Therefore, the Required Actions of Condition E are modified by a Note to indicate that when Condition E is entered with no required AC source to one division, Actions for LC0 3.8.9, " Distribution Systems-Operating," must be immediately entered. This allows Condition E to provide requirements for the loss of the offsite circuit and one DG without regard to whether a division is de-energized.

LC0 3.8.9 provides the appropriate restrictions for a de-energized division.

i According to Regulatory Guide 1.93 (Ref. 6), operation may continue in Condition E for a period that should not exceed i

12 hours1.388889e-4 days 0.00333 hours 1.984127e-5 weeks 4.566e-6 months .

In Condition E, individual 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 sources of power, however, the reliability of the power systems in this Condition may appear higher than that in Condition D (loss of both required offsite circuits).

This difference in reliability is offset by the susceptibility of this power system configuration to a 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, reasonable time for repairs, and low probability of a DBA occurring during this period.

4 (continued)

ABWR TS B 3.8-17 10/21/93

I AC Sources-Operating B 3.8.1 BASES F.1 With two DGs inoperable, there is one remaining standby AC source. Thus, with an assumed loss of offsite electrical power, insufficient standby AC sources are available to power the minimum required ESF functions.

Since the offsite electrical power system is the only source of AC power for the majority of ESF equipment at 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). -Shec eny inadvertent generater tMp-eeuM aho-+esuk--in-a-tet+1-4ess-of-eff44-te AC power, however, the time ellowed-fem +nt4nued-epeea-tion is severeby restric4edr 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 Regulatory Guide 1.93 (Ref. 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 . This Completion Time assumes complete loss of onsite (DG) AC capability to power the minimum loads needed to respond to analyzed events.

G.1 and G.2 If the inoperable AC electrical power sources cannot be restored to OPERABLE status within the associated Completion Time, the unit must be brought to a MODE in which the LC0 does not apply.

To achieve this status, the unit must be brought to MODE 3 within 12 hours1.388889e-4 days 0.00333 hours 1.984127e-5 weeks 4.566e-6 months and to MODE 4 within 36 hours4.166667e-4 days 0.01 hours 5.952381e-5 weeks 1.3698e-5 months .

The allowed Completion Times are reasonable, based on operating experience, to reach the recuired plant conditions from full power conditions in an orcerly manner and without challenging plant systems.

H.1 Condition H corresponds to a level of degradation in which all redundancy in the AC electrical power supplies has been lost. At this severely degraded level, any further losses in the AC electrical power system will cause a loss of function. Therefore, no additional time is justified for

[

(continued)

ABWR TS B 3.8-18 10/21/93 1

1

}

AC Sources-Operating B 3.8.1 BASES ACTIONS H.1 (continued)

(continued) continued operation. The unit is required by LC0 3.0.3 to commence a controlled shutdown.

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

Periodic component tests are supplemented by extensive functional tests during refueling outages under simulated accident conditions.

The SRs for i

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

l Regulatory Guide 1.9 (Ref. 3), and Regulatory Guide 1.137 (Ref. 9).

Where the SRs discussed herein specify voltage and frequency tolerances, the following summary is applicable. The minimum steady state output voltage of 6210 V is 90% of the nominal 6.9 kV output voltage.. This value, which is specified in ANSI C84.1 (Ref. 10 to the terminals of 6600 V mot 6Fs),whose minimum operatingallow voltage is specified as 90%, or 5980 V.

It also allows for voltage drops to motors and other equipment down through the 200 V level where minimum operating voltage is also usually specified as 90% of name plate rating. The specified maximum steady state output voltage of 6674 V is equal to the maximum operating voltage specified for 6600 V motors.

It ensures that for a lightly loaded distribution system, the voltage at the terminals of 6600 V motors is no more than the maximum rated operating voltages. The specified minimum and maximum frequencies of the DG are 58.8 Hz and 61.2 Hz, respectively. These alues are equal to i 2% of the 60 Hz nominal frequency and are derived from the recommendations given in Regulatory Guide 1.9 (Ref. 3).

l SR 3.8.1.1 This SR ensures proper circuit continuity for the offsite AC l

electrical power supply to the onsite distribution network l

and availability of offsite AC electrical power. The breaker alignment verifies that each breaker is in its correct i

position to ensure that distribution buses and loads are (continued)

ABWR TS B 3.8-19 10/21/93

AC Sources-Operating B 3.8.1 BASES SURVEILLANCE SR 3.8.1.1 (continued)

REQUIREMENTS (continued) connected to their preferred power source and that appropriate independence of offsite circuits is maintained.

The 7 day Frequency is adequate since breaker position is not likely to change without the operator being aware of it and because its status is displayed in the control room.

SR 3.8.1.2 and SR 3.8.1.7 These SRs help to ensure the availability of the standby electrical power supply to mitigate DBAs and transients and-maintain the unit in a safe shutdown condition.

To minimize the wear on moving parts that do not get lubricated when the engine is not running, these SRs have been modified by Notes (Note 1 for SR 3.8.1.7 and Note 2 for l

SR 3.8.1.2) to indicate that all DG starts for these l

Surveillances may be preceded by an engine prelube period and followed by a warmup period prior to loading.

i For the purposes of this testing, the DGs are started from standby conditions.

Standby conditions for a DG mean that the diesel engine coolant and oil are being continuously circulated and temperature is being maintained consistent with manufacturer recommendations.

In order to reduce stress and wear on diesel engines, some manufacturers recommend that the starting speed of DGs be limited, that warmup be limited to this lower speed, and that DGs be gradually accelerated to synchronous speed prior to loading. These start procedures are the intent of Note 3, which is only applicable when such procedures are recommended by the manufacturer.

SR 3.8.1.7 requires that, at a 184 day Frequency, the DG starts from standby conditions and achieves required voltage and frequency within 20 seconds. The 20 second start requirement supports the requirements set forth in the SSAR Chapter 8 (Ref. 2). The 20 second start requirement may not be applicable to SR 3.8.1.2 (see Note 3 of SR 3.8.1.2), when a modified start procedure as described above is used.

If a modified start is not used, the 20 second start requirement of SR 3.8.1.7 applies.

Since SR 3.8.1.7 does require a 20 second start, it is more restrictive than SR 3.8.1.2, and (continued)

ABWR TS B 3.8-20 10/21/93

AC Sources-Operating B 3.8.1 BASES SURVEILLANCE SR 3.8.1.2 and SR 3.8.12 (continued)

REQUIREMENTS (continued) it may be performed in lieu of SR 3.8.1.2.

This procedure is the intent of Note 1 of SR 3.8.1.2.

The normal 31 day Frequency for SR 3.8.1.2 (see Table 3.8.1-1, " Diesel Generator Test Schedule") is consistent with Regulatory Guide ilI9' (Ref. 9).

The 184 day Frequency for SR 3.8.1.7 is a rediiEfion in cold. testing consistent with Generic Letter 84-15 (Ref. 7). These Frequencies provide adequate assurance of DG OPERABILITY, while minimizing degradation resulting from testing.

SR 3.8.1.3 This Surveillance demonstrates that the DGs are capable of synchronizing and accepting greater than or equal to th equivalent of the maximum expected accident loads. A minimum run time of 60 minutes is required to stabilize engine temperatures, while minimizing the time that the DG is connected to the offsite source.

In order to ensure that the DG is tested under load conditions that are as close to design basis conditions as possible, testing shall be performed using a power factor less than or equal to 0.9.

This power factor is chosen to be representative of the actual design basis inductive loading that the DG would experience. The load band is provided to avoid routine overloading of the DG.

Routine overloading may result in more frequent tear down inspections in accordance with vendor recommendations in order to maintain DG OPERABILITY.

Thenormal31dayFrequencyforthisSurveillance(Q see Table 3.8.1-1) is consistent with Regulatory Guide (Ref. 9).

Note 1 modifies this Surveillance to indicate that diesel engine runs for this Surveillance may include gradual loading, as recommended by the manufacturer, so that mechanical stress and wear on the diesel engine are minimized.

(continued)

ABWR TS B 3.8-21 10/21/93

AC Sources-Operating B 3.8.1

~

BASES SURVEILLANCE SR 3.8.1.3 (continued)

REQUIREMENTS (continued)

Note 2 modifies this Surveillance by stating that momentary transients because of changing bus loads do not invalidate this test.

Note 3 indicates that this Surveillance should be conducted on only one DG at a time in order to avoid common cause failures that might result from offsite circuit or grid perturbations.

Similarly, momentary power factor transients above the limit do not invalidate the test.

Note 4 stipulates a prerequisite requirement for performance of this SR.

A successful DG start must precede this test to credit satisfactory performance.

SR 3.8.1.4 This SR provides verification that the level of fuel oil in the day tank is at or above the level at which fuel oil is automatically added.

The level is expressed as an equivalent volume in liters, and is selected to ensure adequate fuel oil for a minimum of I hour of DG operation at full load plus 10%.

The 31 day Frequency is adequate to assure that a sufficient supply of fuel oil is available, since low level alarms are provided and facility operators would be aware of any large uses of fuel oil during this period.

SR 3.8.1.5 Microbiological fouling is a major cause of fuel oil degradation.

There are numerous bacteria that can grow in fuel oil and cause fouling, but all must have a water environment in order to survive.

Removal of water from the fuel oil day tanks once every 31 days eliminates the necessary environment for bacterial survival.

This is most effective means in controlling microbiological fouling.

In addition, it eliminates the potential for water entrainment in the fuel oil during DG operation.

Water may come from any of several sources, including condensation, ground water, rain water, contaminated fuel oil, and breakdown of the fuel oil by bacteria.

Frequent checking for and removal (continued)

ABWR TS B 3.8-22 10/21/93

AC Sources-Operating B 3.8.1 i

BASES i

i SURVEILLANCE SR 3.8.1.5 (continued) i REQUIREMENTS (continued) of accumulated water minimizes fouling and provides data regarding the watertight integrity of the fuel oil system.

The Surveillance Frequencies are established by Regulatory Guide 1.137 (Ref. 9). This SR is for preventive maintenance. The presence of water does not necessarily represent a failure of this SR provided that accumulated water is removed during performance of this Surveillance.

SR 3.8.1.6 j

This Surveillance demonstrates that each required fuel oil transfer pump operates and transfers fuel oil from its associated storage tank to its associated day tank.

It is required to support the continuous operation of standby power sources.

This Surveillance provides assurance that the fuel oil transfer pump is OPERABLE, the fuel oil piping system is intact, the fuel delivery piping is not obstructed, and the controls and control systems for automatic fuel transfer systems are OPERABLE. ThTs%fstTsif heMrf6fmedMy]AMijd1jtedToRAMUllWUf6 sit]QrjjjistlAn signal _.;

I The frequency for this SR is variable, depending on individual system design, with up to a 92 day interval.

The 92 day Frequency corresponds to the testing requirements for pumps as contained in the ASME Boiler and Pressure Vessel Code,Section XI (Ref. 11); however, the design of fuel transfer systems is such'that pumps operate automatically or must be started manually in order to maintain an adequate volume of fuel oil in the day tanks during or following DG testing.

In such a case, a 31 day Frequency is appropriate.

Since proper operation of fuel transfer systems is an inherent part of DG OPERABILITY, the Frequency of this SR should be modified to reflect individual designs.

SR 3.8.1.7 See SR 3.8.1.2.

(continued)

ABWR TS B 3.8-23 10/21/93

AC Sources-0perating B 3.8.1 BASES SURVEILLANCE SR 3.8.1.8 REQUIREMENTS (continued)

Manual transfer of each 6.9 kV ESF bus power supply from the normal offsite circuit to the alternate offsite circuit demonstrates the OPERABILITY of the alternate circuit distribution network to Tlii i

shiinilitysasfs$shniTd% power the shutdown loads.

eipbEf6FaiMilii thsg oad ss(f ";e) g' Sur[ veil l anc;bu sit rans f@

i!

notafdead eisbasedo)yThe18 month Frequency o th'e n engineering judgment taking into consideration the plant conditions required to perform the Surveillance, and is intended to be consistent with expected fuel cycle lengths. Operating experience has shown that these components usually pass the SR when performed on the 18 month Frequency. Therefore, the frequency was concluded to be acceptable from a reliability standpoint.

This SR is modified by two Notes. The reason for Note 1 is that, during operation with the reactor critical, performance of this SR could cause perturbations to the electrical distribution systems that could challenge entwined steady state operation and, as a result, plant safety systems. Note 2 acknowledges that credit may be taken for unplanned events that satisfy this SR.

SR 3.8.1.9 Each DG is provided with an engine overspeed trip to prevent damage to the engine.

Recovery from the transient caused by the loss of a large load could cause diesel engine overspeed, which, if excessive, might result in a trip of the engine. This Surveillance demonstrates the DG load response characteristics and capability to reject the largest single load without exceeding predetermined voltage and frequency and while maintaining a specified margin to the overspeed trip. The load referenced for Division 2 and Division 3 DGs is the 1400 kW high pressure core flooder (HPCF) pump; for the livision 1 DG, the 540 kW residual heat removal (RHR) pump.

ihe Reactor Building Cooling Water (RCW) system load was not used.

Even though the load to DG 1 is 640 kW, that value consists of 2. RCW pumps of 320 kW each. As required by IEEE-308 (Ref. 12), the load rejection test is acceptable if the increase in~ diesel speed does not exceed 75% of the difference between synchronous speed and (continued)

ABWR TS B 3.8-24 10/21/93

AC Sources-Operating B 3.8.1 BASES SURVEILLANCE SR 3.8.1.9 (continued)

REQUIREMENTS (continued) the overspeed trip setpoint, or 15% above synchronous speed, whichever is lower.

The time, voltage, and frequcncy tolerances specified in this SR are derived from Regulatory Guide 1.9 (Ref. 3) recommendations for response during load sequence intervals.

The 3. seconds specified is equal to 60% of tha 5 second-load sequence interval associated with sequencing of this largest load. The voltage and frequency specified are consistent with the design range of the equipment powered by the-DG.

SR 3.8.1.9.a corresponds to the maximum frequency excursion, while SR 3.8.1.9.b and SR 3.8.1.9.c are steady state voltage and frequency values to which the system must recover following load rejection.

The [18 month] Frequency is consistent with the recommendation of Regulatory Guide Q..

(Ref. ;l).

In order to ensure that the DG is tested under load conditions that are as close to design basis conditions as possible, testing must be performed using a power factor s[

].

This power factor-is chosen to be representative of the actual design basis inductive loading that the DG could experience.

This SR has been modified by two Notes. The reason for Note 1 is that during operation with the reactor critical, performance of this SR could cause perturbations. to the electrical distribution systems that could challenge continued steady state operation and, as a result, plant safety systems.

Note 2' acknowledges that credit may be taken for unplanned events that satisfy this SR.

Reviewer's Note:

The above MODE restrictions may be deleted if it can be demonstrated to the staff, on a plant specific basis, that performing the SR with the reactor in any of the restricted MODES can satisfy the following criteria, as applicable:

a.

Performance of the SR will not render any safety system or component inoperable; b.

Performance of the SR will not cause perturbations to any of the electrical distribution systems that could (continued)

ABWR TS B 3.8-25 10/21/93 -

1 1

i

AC Sources-Operating -

B 3.8.1 BASES SURVEILLANCE SR.3 1.122 (continued)

REQUIREMENTS (continued) result in a challenge to steady state operation or to plant safety systems; and c.

Performance of the SR, or failure of the SR, will not cause, or result in, an A00 with attendant challenge to plant safety systems.

SR 3.8.1.10 This Surveillance demonstrates the DG capability to reject a full load without overspeed tripping or exceeding the predetermined voltage limits.

The DG full load rejection may occur because of a system fault or inadvertent breaker tripping. This Surveillance ensures proper engine generator load response under the simulated test conditions. This test simulates the loss of the total connected load that the DG experiences following a full load rejection and verifies that the DG does not trip upon loss of the load. These acceptance criteria provide DG damage protection. While the DG is not expected to experience this transient during an event, and continues to be available, this response ensures that the DG is not degraded for future application, including reconnection to the bus if the trip initiator can be corrected or isolated.

In order to ensure that the DG is tested under load conditions that are as close to design basis conditions as possible, testing must be performed using a power factor s 0.9.

This power factor is chosen to be representative of the actual design basis inductive loading that the DG would experience.

The [18 month] Frequency is consistent with the recommendation of Regulatory Guide 1.108 (Ref. 9) and is intended to be consistent with expected fuel cycle lengths.

This SR has been modified by two Notes. The reason for Note 1 is that during operation with the reactor critical, performance of this SR could cause perturbation to the electrical distribution systems that could challenge continued steady state operation and, as a result, plant safety systems.

Note 2 acknowledges that credit may be taken for unplanned events that satisfy this SR.

(continued)

ABWR TS B 3.8-26 10/21/93

AC Sources-Operating B 3.8.1 j

BASES SURVEILLANCE SR 3.8.1.10 (continued)

REQUIREMENTS (continued)

Reviewer's Note: The above MODE restrictions may be deleted if it can be demonstrated to the staff, on a plant specific basis, that performing the SR with the reactor in any of the restricted MODES can satisfy the following criteria, as applicable:

a.

Performance of the SR will not render any safety system or component inoperable; 1

b.

Performance of the SR will not cause perturbations to any of the electrical distribution systems that could result in a challenge to steady state operation or to i

plant safety systems; and c.

Performance of the SR, or failure of the SR, will not cause, or result in, an A00 with attendant challenge to plant safety systems.

SR 3.8.1.11 As required by Regulatory Guide 1!9 (Ref. 3),

paragraph 2:2.4, this Surveillance"demonstfates the as designed opeFation of the standby power sources during loss of the offsite source. This test verifies all actions encountered from the loss of offsite power, including energization of the emergency buses and respective loads from the DG.

It further demonstrates the capabilitv of the DG to automatically achieve the required voltage and frequency within the specified time.

The DG auto-start time of 20 seconds is derived from requirements stated in the SSAR Chapter 8 (Ref. 2).

The frequency should be restored to within 2% of nominal i

l following a load sequence step.

The Surveillance should be continued for a minimum of 5 minutes in order to demonstrate that all starting transients have decayed and stability has been achieved.

The requirement to verify the connection and power supply of permanent and auto-connected loads is intended to satisfactorily show the relationship of these loads to the (continued)

ABWR TS B 3.8-27 10/21/93

AC Sources-Operating B 3.8.1 BASES SURVEILLANCE SR 3.8.1.11 (continued)

REQUIREMENTS (continued)

DG loading logic.

In certain circumstances, many of these loads cannot actually be connected or loaded without undue hardship or potential for undesired operation.

For instance, ECCS injection valves are not desired to be stroked open, high pressure injection systems are not capable of being operated at full flow, or RHR systems performing a decay heat removal function are not desired to be realigned to the ECCS mode of operation.

In lieu of actual demonstration of the connection and loading of these loads, testing that adequately shows the capability of the DG system to perform these functions is acceptable.

This testing may include any series of sequential, overlapping, or total steps so that the entira connection and loading sequence is verified.

The Frequency of 18 months is consistent with the recommendations of Regulatory Guide 1.'9' (Ref. 3),

paragraph 2.214, takes into considerition unit" conditions required to pW form the Surveillance, and is intended to be

~

consistent with expected fuel cycle lengths.

This SR is modified by three Notes.

The reason for Note 1 is to minimize wear and tear on the DGs during testing.

For the purpose of this testing, the DGs must be started from standby conditions, that is, with the engine coolant and oil being continuously circulated and temperature maintained consistent with manufacturer recommendations. The reason for Note 2 is that performing the Surveillance would remove a required offsite circuit from service, perturb the electrical distribution system, and challenge plant safety systems.

Note 3 acknowledges that credit may be taken for unplanned events that satisfy this SR.

SR 3.8.1.12 This Surveillance demonstrates that the DG automatically starts and achieves the required voltage and frequency within the specified time (20 seconds) from the design basis actuation signal (LOCA signal) and operates for 2 5 minutes.

The 5 minute period provides sufficient time to demonstrate stability. SR 3.8.1.12.d and SR 3.8.1.12.e ensure that (continued)

ABWR TS B 3.8-28 10/21/93

AC Sources-Operating B 3.8.1 BASES SURVEILLANCE SR 3.8.1.12 (continued)

REQUIREMENTS (continued) permanently connected loads and emergency loads are energized from the offsite electrical power system on an ECCS signal without loss of offsite power.

The requirement to verify the connection and power supply of permanent and autoconnected loads is intended to satisfactorily show the relationship of these loads to the loading logic for loading onto offsite power.

In certain circumstances, many of these loads cannot actually be connected or loaded without undue hardship or potential for undesired operation.

For instance, ECCS injection valves are not desired to be stroked open, high pressure injection systems are not capable of being operated at full flow, or RHR systems performing a decay heat removal function are not desired to be realigned to the ECCS mode of operation.

In lieu of actual demonstration of the connection and loading of these loads, testing that adequately shows the capability of the DG system to perform these functions is acceptable.

This testing may include any series of sequential, overlapping, or total steps so that the entire connection and loading sequence is verified.

The Frequency of 18 months takes into consideration plant conditions required to perform the Surveillance and is intended to be consistent with the expected fuel cycle lengths. Operating experience has shown that these components usually pass the SR when performed at the 18 month Frequency. Therefore, the Frequency was concluded to be acceptable from a reliability standpoint.

This SR is modified by three Notes. The reason for Note 1 is to minimize wear and tear on the DGs during testing.

For the purpose of this testing, the DGs must be started from standby conditions, that is, with the engine coolant and oil being continuously circulated and temperature maintained consistent with manufacturer recommendations.

The reason for Note 2 is that during operation with the reactor critical, performance of this SR could cause perturbations to the electrical distribution systems that could challenge continued steady state operation and, as a result, plant safety systems. Note 3 acknowledges that credit may be taken for unplanned events that satisfy this SR.

(continued)

ABWR TS B 3.8-29 10/21/93

AC Sources-Operating B 3.8.1 BASES SR 3.8.1.13 This Surveillance demonstrates that DG non-critical protective functions (e.g., high jacket water temperature) are bypassed on a loss of voltage signal concurrent with an ECCS initiation test signal and critical protective functions (engine overspeed and generator differential current) trip the DG to avert substantial damage to the DG unit.

The non-critical trips are bypassed during DBAs and provide an alarm on an abnormal engine condition. This alarm provides the operator with sufficient time to react appropriately. The DG availability to mitigate the DBA is more critical than protecting the engine against minor problems that are not immediately detrimental to emergency operation of the DG.

The 18 month Frequency is based on engineering judgment, taking into consideration plant conditions required to perform the Surveillance, and is intended to be consistent with expected fuel cycle lengths.

Operating experience has shown that these components usually pass the SR when performed at the 18 month Frequency. Therefore, the Frequency was concluded to be acceptable from a reliability standpoint.

The SR is modified by two Notes. The reason for Note 1 is that performing the Surveillance removes a required DG from service.

Note 2 acknowledges that credit may be taken for unplanned events that satisfy this SR.

Reviewer's Note: The above MODE restrictions may be deleted if it can be demonstrated to the staff, on a plant specific basis, that performing the SR with the reactor in any of the restricted MODES can satisfy the following criteria, as applicable:

a.

Performance of the SR will not render any safety system or component inoperable; b.

Performance of the SR will not cause perturbations to any of the electrical distribution systems that could result in a challenge to steady state operation or to plant safety systems; and

-~

(cont i nued)"--

ABWR TS B 3.8-30 10/21/93

m

~ AC Sources-Operating

-I B 3.8.1 BASES SURVEILLANCE SR 3.8.1.13 (continued)

REQUIREMENTS-(continued) c.

Performance of the SR,-or failure of the SR, will not-cause, or result in, an A00 with attendant challenge to plant safety systems.

SR 3.8.1.14 demonstrationonceper18monthsthatthe$23, requires Regulatory Guide gg (Ref. 3), paragraph DGs can start and run continuously at full load capability for an interval of not less than 24 hour2.777778e-4 days 0.00667 hours 3.968254e-5 weeks 9.132e-6 months s-22 hours of which 'is at-a load equivalent to ' 0?f6E10'Of6Qthe continuous rating of the DG, 9

and 2 hours2.314815e-5 days 5.555556e-4 hours 3.306878e-6 weeks 7.61e-7 months of~ Midi ~fi'It'a load equivalent to 10$YiB 1100 t

of the continuous duty-rating of the DG. The DG'~itIFfs for. -

this Surveillance can be performed either-from standby or-hot conditions. The provisions for prelube and warmup, discussed in SR 3.8.1.2, and for gradual loading, discussed

-)

in SR 3.8.1.3, are applicable to this SR.

In order to ensure that the DG is tested under load conditions that are as close to~ design conditions as possible, testing must be performed using a power factor s 0.9.

This power factor is chosen to be representative f the actual design basis inductive. loading that the DG could experience.

The 18 month Frequency is consistent with the paragraph 212V9'; takes into considerifi]a]n~iSliiif) conditions recommendations of Regulatory Guide Ff9 Riff!3,

required t'~iiifform the Surveillance; and is intended to be o

consistent with expected fuel cycle lengths.

This Surveillance is modified by three Notes.

Note 1 states that momentary transients due to changing bus loads do not invalidate this test. The load band is provided to avoid routine overloading of the DG.

Routine overloading may result in more frequent tear down inspections in accordance l

with vendor recommendations in order to maintain DG i

OPERABILITY.

Similarly, momentary power factor transients above the limit do not invalidate the test. The reason for Note 2 is that during operation with the reactor critical, performance of this SR could cause perturbations to the electrical distribution systems that would challenge continued steady state operation and, as a result, plant (continued)

ABWR TS B 3.8-31 10/21/93

)

~1 AC Sources-Operating i

B 3.8.1 i

BASES SURVEILLANCE SR 3.8.1.14 (continued)

REQUIREMENTS (continued) safety systems. Note 3 acknowledges that credit may be taken for unplanned events that satisfy this SR.

SR 3.8.1.15 This Surveillance demonstrates that the diesel engine can restart from a hot condition, such as subsequent to shutdown from normal Surveillances, and achieve the required voltage and frequency within 20 seconds. The 20-second time is-derived from the requirements set forth in the SSAR Chapter 8 (Ref. 2).

The 18 month Frequency is consistent with the recommendations of Regulatory Guide )$9{(@fg3{,

paragraph 222.10.

This SR has been modified by two Notes. Note 1 ensures that the test is performed with the diesel sufficiently hot.

The requirement that the diesel has operated for at least 2 hours2.314815e-5 days 5.555556e-4 hours 3.306878e-6 weeks 7.61e-7 months at full load conditions prior to performance of this Surveillance is based on manufacturer recommendations for achieving hot conditions. The load band is provided to avoid routine overloading of the DG.

Routine overloads may result in more frequent tear down inspections in accordance with vendor recommendations in order to maintain DG OPERABILITY. Momentary transients due to changing bus loads do not invalidate this test.

Note 2 allows all DG starts to be preceded by an engine prelube period to minimize wear and tear on the diesel during testing.

SR 3.8.1.16 As required.by Regulatory Guide !!9(*(RsM3J, paragraph 2s2fl1~, this SurveillascE en~s0FEi"that the manual synchronizati6n~and automatic load transfer from the DG to the offsite source can be made and that the DG can be returned to ready-to-load status when offsite power is restored.

It also ensures that the auto-start logic is reset to allow the DG to reload if a subsequent loss of offsite power occurs. The DG is considered to be in ready-to-load status when the DG is at rated speed and voltage, the output breaker is open and can receive an (continued)

ABWR TS B 3.8-32 10/21/93

AC Sources-Operating B 3.8.1 BASES SURVEILLANCE SR 3.8.1 16 (continued)

REQUIREMENTS (continued) auto-close signal on bus undervoltage, and the load timers are reset.

The Frequency of 18 months is consistent with the recommendations of Regulatory Guide H91T NS E 3andtakesintoconildir(itT6i paragraph 212111, plant conditions required to perform the Surveillance.

This SR is modified by two Notes. The reason for Note 1 is that performing the Surveillance would remove a required offsite circuit from service, perturb the electrical distribution system, and challenge safety systems. Note 2 acknowledges that credit may be taken for unplanned events that satisfy this SR.

SR 3.8.1.17 Demonstration of the test mode override ensures that the DG availability under accident conditions is not compromised as the result of testing.

Interlocks to the LOCA sensing circuits cause the DG to automatically reset to ready-to-load operation 6fian ECCS initiation signal is received during operatioii"in the test mode.

Ready-to-load operation is defined as the DG running at rated speed and voltage with the DG output breaker open. These provisions for automatic switchover are required by IEEE-308 (Ref. g),

paragraph 6.2.6(2).

The requirement to automatically energize the emergency loads with offsite power is essentially identical to that of SR 3.8.1.12.

The intent in the requirement associated with SR 3.8.1.17.b is to show that the emergency loading is not affected by the DG operation in test mode.

In lieu of actual demonstration of connection and loading of loads, testing that adequately shows the capability of the emergency loads to perform these functions is acceptable.

This testing may include any series of sequential, overlapping, or total steps so that the entire connection and loading sequence is verified.

The 18 month Frequency is consistent with the paragraph 2.2(s of Regulatory Guide lj9}(njifM3{,1.3; takes into conside recommendation (continued)

ABWR TS B 3.8-33 10/21/93

AC Sources-Operating B 3.8.1 BASES SURVEILLANCE SR 3.8.1.17 (continued)

REQUIREMENTS (continued) required to perform the Surveillance; and is intended to be consistent with expected fuel cycle lengths.

This SR has been modified by two Notes.

The reason for Note 1 is that performing the Surveillance would remove a required offsite circuit from service, perturb the electrical distribution system, and challenge safety systems. Note 2 acknowledges that credit may be taken for unplanned events that satisfy this SR.

SR 3.8.1.18 As required by Regulatory Guide 1391(R6fM3),

paragraph 212.6, each DG is required ti deiiionstrate proper operation for the DBA loading sequence to ensure that voltage and frequency are maintained within the required limits.

Under accident conditions, prior to connecting the DGs to their respective bus, all loads are shed except load center feeders and those motor control centers that power Class lE loads (referred to as " permanently connected" loads).

Upon reaching 90% rated voltage and frequency, the DGs are then connected to their respective bus.

Load shedding and buses-ready-to-load signals are generated by the control systems for the electrical power distribution system.

Individual timers for each major load are reset and started by their electrical power distribution systems signals (Ref. 2). The 10% load sequence time interval tolerance ensures that sufficient time exists for the DG to restore frequency and voltage prior to applying the next load and that safety analysis assumptions regarding ESF equipment time delays are not violated.

Regulatory Guide 1.9 (Ref. 3) provides a summary of the automatic loading of ESF buses.

i The Frequency of 18 months is consistent with the paragraph 2.2.~6;takesintoconsiderati6n(RsfE3) recommendations of Regulatory Guide l!9f

~ liht conditions p

i required to ' perform the Surveillance; and is intended to be consistent with expected fuel cycle lengths.

This SR is modified by two Notes. The reason for Note 1 is that performing the Surveillance during these MODES would remove a required offsite circuit from service, perturb the (continued) l ABWR TS B 3.8-34 10/21/93

AC Sources-Operating B 3.8.1 BASES SURVEILLANCE SR 3.8.1.18 (continued)

REQUIREMENTS (continued) electrical distribution system, and challenge plant safety systems.

Note 2 acknowledges that credit may be taken for unplanned events that satisfy this SR.

)

Reviewer's Note: The above MODE restrictions may be deleted if it can be demonstrated to the staff. on a plant specific basis, that performing the SR with the reactor in any of the restricted MODES can satisfy the following criteria, as applicable:

a.

Performance of the SR will not render any safety system or component inoperable; b.

Performance of the SR will not cause perturbations to any of the electrical distribution systems that could result in a challenge to steady state operation or to plant safety systems; and c.

Performance of the SR, or failure of the SR, will not cause, or result in, an A00 with attendant challenge to plant safety systems.

SR 3.8.1.19 In the event of a DBA coincident with a loss of offsite power, the DGs are required to supply the necessary power to ESF systems so that the fuel, RCS, and containment design limits are not exceeded.

This Surveillance demonstrates the DG operation, as discussed in the Bases for SR 3.8.1.11, during a loss of offsite power actuation test signal in conjunction with an ECCS initiation signal.

In lieu of actual demonstration of i

connection and loading of loads, testing that adequately shows the capability of the DG system to perform these functions is acceptable. This testing may include any series of sequential, overlapping, or total steps so that the entire connection and loading sequence is verified.

The Frequency of 18 months takes into consideration plant conditions required to perform the Surveillance and is (continued)

ABWR TS B 3.8-35 10/21/93

AC Sources-Operating B 3.8.1 BASES SURVEILLANCE SR 3.8.1.19 (continued)

REQUIREMENTS (continued) intended to be consistent with an expected fuel cycle length of 18 months.

This SR is modified by three Notes.

The reason for Note 1 is to minimize wear and tear on the DGs during testing. For the purpose of this testing, the DGs must be started from standby conditions, that is, with the engine coolant and oil being continuously circulated and temperature maintained consistent with manufacturer recommendations.

The reason for Note 2 is that performing the Surveillance would remove a required offsite circuit from service, perturb the' electrical distribution system, and challenge plant safety systems. Note 3 acknowledges that credit may be taken for unplanned events that satisfy this SR.

SR 3.8.1.20 This Surveillance demonstrates that the DG starting independence has not been compromised. Also, this Surveillance demonstrates that each engine can achieve proper speed within the specified time when the DGs are started simultaneously.

The 10 year Frequency is consistent with the recommendations of Regulatory Guide fi9?(RsfM3)', paragraph 21f2714, and Regulatory Guide 1.137'(Re C~9), paragraph C'.'2.f -

This SR is modified by a Note.

The reason for the Note is j

to minimize wear on the DG during testing.

For the purpose of this testing, the DGs must be started from standby conditions, that is, with the engine coolant and oil continuously circulated and temperature maintained consistent with manufacturer recommendations.

Diesel Generator Test Schedule The DG test schedule (Table 3.8.1-1) implements the recommendations of Revision 3 to Regulatory Guide 1.9 j

(Ref. 3). The purpose of this test schedule is to provide i

timely test data to establish a confidence level associated wit.h the goal to maintain DG reliability at > 0.95 per test.

(continued)

ABWR TS B 3.8-36 10/21/93

AC Sources-Operating B 3.8.1 BASES SURVEILLANCE SR

3. 8.1. LQ (continued)

REQUIREMENTS (continued)

According to Regulatory Guide 1.9 (Ref. 3), Revision 3, each DG unit should be tested at least once every 31 days.

Whenever a DG has experienced 4 or more valid failures in the last 25 valid tests, the maximum time between tests is reduced to 7 days.

Four failures in 25 valid tests is a failure rate of 0.16, or the threshold of acceptable DG performance, and hence may be an early indication of the degradation of DG reliability. When considered in the light of a long history of tests, however, 4 failures in the last 25 valid tests may only be a statistically probable distribution of random events.

Increasing the test Frequency allows a more timely accumulation of additional test data upon which to base judgment of the reliability of the DG.

The increased test frequency must be maintained until seven consecutive failure free tests have been performed.

The Frequency for accelerated testing is 7 days, but no less than 24 hours2.777778e-4 days 0.00667 hours 3.968254e-5 weeks 9.132e-6 months .

Therefore, the interval between tests should be no less than 24 hours2.777778e-4 days 0.00667 hours 3.968254e-5 weeks 9.132e-6 months , and no more than 7 days. A successful test at an interval of less than 24 hours2.777778e-4 days 0.00667 hours 3.968254e-5 weeks 9.132e-6 months should be considered an invalid test and not count towards the seven consecutive failure free starts. A test interval in excess of 7 days constitutes a failure to meet SRs.

REFERENCES 1.

10 CFR 50, Appendix A, GDC 17.

2.

ABWR SSAR, Chapter 8.

3.

Regulatory Guide 1.9, ReVisid3) 4.

ABWR SSAR, Chapter 6.

5.

ABWR SSAR, Chapter 15.

6.

Regulatory Guide 1.93.

7.

Generic Letter 84-15, July 2, 1984.

8.

10 CFR 50, Appendix A, GDC 18, 9.

Regulatory Guide 1.137.

(continued)

ABWR TS B 3.8-37 10/21/93 1

AC Sources-Operating B 3.8.1 BASES REFERENCES (continued) 10.

ANSI C84.1, 1982.

11.

ASME, Boiler and Pressure Vessel Code,Section XI.

12.

IEEE Standard 308.

ABWR TS B 3.8-38 10/21/93

DC Sources-Operating 3.8.4 4

3.8 ELECTRICAL POWER SYSTEMS 3.8.4 DC Sources-Operating LC0 3.8.4 The Division I, Division II, Division III, and Division IV DC electrical power subsystems shall be OPERABLE.

APPLICABILITY:

MODES I, 2, and 3.

ACTIONS CONDITION REQUIRED ACTION COMPLETION TIME A.

One DC electrical A.1 Determine OPERABLE DC 2 hours2.314815e-5 days 5.555556e-4 hours 3.306878e-6 weeks 7.61e-7 months power subsystem electrical subsystems (either Division I, are not inoperable II, or III) due to common cause inoperable, failure.

AND A.2 Declare affected 2 hours2.314815e-5 days 5.555556e-4 hours 3.306878e-6 weeks 7.61e-7 months required features inoperable.

AND A.3 Verify the combustion 12 hours1.388889e-4 days 0.00333 hours 1.984127e-5 weeks 4.566e-6 months turbine generator (CTG) is functional by verifying the CTG starts and achieves steady state voltage and frequency within 10 minutes.

AND A.4 Verify the CTG 12 hours1.388889e-4 days 0.00333 hours 1.984127e-5 weeks 4.566e-6 months circuit breakers are capable of being AND aligned to each of three 6.9 kV once per 8 hours9.259259e-5 days 0.00222 hours 1.322751e-5 weeks 3.044e-6 months essential AC buses, thereafter t

(continued)

ABWR TS 3.8-I 10/21/93

1 DC Sources-Operating 3.8.4 ACTIONS (continued)

CONDITION REQUIRED' ACTION COMPLETION TIME f

A.

(continued)

A.5 Restore inoperable DC 72 hours8.333333e-4 days 0.02 hours 1.190476e-4 weeks 2.7396e-5 months electrical power subsystem to OPERABLE status.

f B.

Division IV DC B.1 Restore Division 4 DC 12 hours1.388889e-4 days 0.00333 hours 1.984127e-5 weeks 4.566e-6 months electrical power electrical power subsystem inoperable.

subsystem to OPERABLE status.

OR B.2 Declare affected 12 hours1.388889e-4 days 0.00333 hours 1.984127e-5 weeks 4.566e-6 months required features inoperable.

C.

One DC electrical C.1 Restore inoperable DC 2 hours2.314815e-5 days 5.555556e-4 hours 3.306878e-6 weeks 7.61e-7 months power subsystem electrical power (either Division I, subsystem (other than II, or III)

Division IV) to inoperable.

OPERABLE status.

AND 0J Division IV DC C.2 Restore Division IV 2 hours2.314815e-5 days 5.555556e-4 hours 3.306878e-6 weeks 7.61e-7 months electrical power DC electrical power subsystem inoperable.

subsystem to OPERABLE status.

D.

Required Action and D.1 Be in MODE 3.

12 hours1.388889e-4 days 0.00333 hours 1.984127e-5 weeks 4.566e-6 months associated Completion Time not met.

AND D.2 Be in MODE 4.

36 hours4.166667e-4 days 0.01 hours 5.952381e-5 weeks 1.3698e-5 months ABWR TS 3.8-2 10/21/93

DC Sources-Operating 3.8.4 -

SURVEILLANCE REQUIREMENTS SURVEILLANCE FREQUENCY SR 3.8.4.1 Verify battery terminal voltage is 7 days 2[

] V on float charge.

SR 3.8.4.2 Verify no visible corrosion at terminals 92 days and connectors.

og Verify connection resistance is s[

] ohms for inter-cell connections, s[

] ohms for inter-rack connections, s[

] ohms for inter-tier connections, and 5 [

] ohms for terminal connections.

SR 3.8.4.3 Verify cells, cell plates, and battery 12 months racks show no visual indication of physical damage or abnormal deterioration.

SR 3.8.4.4 Remove visible corrosion, and verify cell 12 months to cell and terminal connections are clean and coated with anti-corrosion material.

SR 3.8.4.5 Verify connection resistance is 12 months s[

] ohms for inter-cell connections, s[

] ohms for inter-rack connections, s[

] ohms for inter-tier connections, and s [

] ohms for terminal connections).

(continued) 1 ABWR TS 3.8-3 10/21/93 i

DC Sources-Operating 3.8.4 SURVEILLANCE REQUIREMENTS (continued)

SURVEILLANCE FREQUENCY l

SR 3.8.4.6

NOTES-------------------

1.

This Surveillance shall not be performed in MODE 1, 2, or 3.

2.

Credit may be taken for unplanned events that satisfy this SR.

Verify each required battery charger 18 months supplies 2 [

] amps at 2125 Y for 2 12 hours1.388889e-4 days 0.00333 hours 1.984127e-5 weeks 4.566e-6 months .

I SR 3.8.4.7

NOTES-------------------

1.

A modified performance discharge test may be performed in lieu of a service test once per 60 months.

2.

This Surveillance shall not be performed in MODE 1, 2, or 3.

3.

Credit may be taken for unplanned events that satisfy this SR.

18 months Verify battery capacity is adequate to supply, and maintain in OPERABLE status, the required emergency loads for the design duty cycle when subjected to a battery service test.

(continued) i ABWR TS 3.8-4 10/21/93

.w e

1 DC Sources-Operating 3.8.4 SURVEILLANCE REQUIREMENTS (continued)

SURVEILLANCE FREQUENCY SR 3.8.4.8

NOTES-------------------

1.

This Surveillance shall not be performed in MODE 1, 2, or 3.

2.

Credit may be taken for unplanned events that satisfy this SR.

Verify battery capacity is 2 80% of the 60 months manufacturer's rating when subjected to a performance discharge test.

6HD

NOTE------

Only applicable when battery shoWs degradation or l

has reached 85%

of expected life.

j 12 months 1

l ABWR TS 3.8-5 10/21/93

DC Sources-Operating B 3.8.4 8 3.8 ELECTRICAL POWER SYSTEMS B 3.8.4 DC Sources-Operating BASES BACKGROUND The station DC electrical power system provides the AC power system with control power.

It also provides both motive and control power to selected safety related equipment. As required by 10 CFR 50, Appendix A, GDC 17 (Ref.1), the DC electrical power system is designed to have sufficient independence, redundancy, and testability to perform its safety functions, assuming a single failure. The DC electrical power system also conforms to the requirements of Regulatory Guide 1.6 (Ref. 2) and IEEE-308 (Ref. 3).

The 125 VDC electrical power system consists of four independent Class IE DC electrical power subsystems, Givisions I, II, III, and IV.

Each subsystem consists of a battery, associated batter) charger, and all the associated control equipment and interconnecting cabling.

In addition there are two standby backup chargers. One is shared by Divisions I and II, and the other is shared by Divisions III and IV. However, no credit is taken for the backup battery chargers which are not required to be OPERABLE or surveillance tested.

During normal operation, the DC loads are powered from the battery chargers with the batteries floating on the system.

In case of loss of AC power to the battery charger, the DC loads are automatically powered from the batteries.

Division I, II, and III DC electrical power subsystems provides the control power for its associated Class 1E AC power system.

Each of these three DC electrical power subsystems provides both motive and control power, as necessary, to associated safety related components (Division IV supplies neither motive nor control power). All four DC electrical power subsystems provide DC electrical power to essential instrumentation and logic within their respective divisions as well as to the inverters, which in turn power the AC vital buses. All four subsystems also provide motive and control power for DC emergency lighting systems.

(continued)

ABWR TS B 3.8-1 10/21/93

l DC Sources-0perating B 3.8.4 BASES BACKGROUND The DC power distribution system is described in more detail (continued) in Bases for LCO 3.8.9, " Distribution Systems-0perating,"

and LC0 3.8.10, " Distribution Systems -Shutdown."

Each battery for Division I, II, III, and IV has adequate storage capacity to carry the required load continuously for at least 2 hours2.314815e-5 days 5.555556e-4 hours 3.306878e-6 weeks 7.61e-7 months .

The battery for Division I, which controls the RCIC system, also has adequate storage capacity for eight hours of operation during station blackout (Ref.

12).

Each DC subsystem battery is separately housed in a ventilated room apart from its charger and distribution centers.

Each subsystem is located in an area separated physically and electrically from the other subsystems to ensure that a single failure in one subsystem does not cause a failure in a redundant subsystem.

There is no sharing between redundant Class IE DC subsystems such as batteries, battery chargers, or distribution panels.

The maximum equalizing charge for Class IE batteries is 140 V.

The DC system mimimum discharge voltage at the end of the discharge period is 1.75 V per cell (105 V for the battery). The operating voltage range of the Class 1E DC subsystem loads is 100 to 140 V.

Each of the four battery chargers for Division I, II, III, and IV DC electrical power subsystems has ample power output capacity for the steady state operation of its Division's connected loads required during normal operation, while at the same time maintaining its battery bank fully charged.

Each battery charger has sufficient capacity to restore its battery bank from the design minimum charge to within 95% of its fully charged state within 12 hours1.388889e-4 days 0.00333 hours 1.984127e-5 weeks 4.566e-6 months while supplying the largest combined demand of the various continuous steady state loads (Ref. 4).

APPLICABLE The initial conditions of Design Basis Accident (DBA) and SAFETY ANALYSES transient analyses in the SSAR, Chapter 6 (Ref. 5) and Chapter 15 (Ref. 6), assume that ESF systems are OPERABLE.

The DC electrical power system provides DC electrical power for ESF systems, ESF support systems including the DGs and its support systems, and control and switching during all MODES of operation.

(continued)

ABWR TS B 3.8-2 10/21/93

DC Sources-Operating B 3.8.4 BASES APPLICABLE The OPERABILITY of the DC subsystems is consistent with the SAFETY ANALYSES initial assumptions of the accident analyses and is based (continued) upon meeting the design basis of the unit.

This includes maintaining DC sources OPERABLE during accident conditions in the event of:

a.

An assumed loss of all offsite AC power or of all onsite AC power; and b.

A worst case single failure.

The DC sources satisfy Criterion 3 of the NRC Policy Statement.

LC0 The four DC electrical power subsystems are required to be OPERABLE to ensure the availability of the required power to shut down the reactor and maintain it in a safe condition after an anticipated operational occurrence (A00) or a postulated DBA.

Loss of any DC electrical power subsystem does not prevent the minimum safety function from being performed (Ref. 4).

Each subsystem (or Division) consists of one battery, one battery charger, and the corresponding control equipment and interconnecting cabling within the subsystem.

APPLICABILITY The DC electrical power sources are required to be OPERABLE in MODES 1, 2, and 3 to ensure safe unit operation and to ensure that:

a.

Acceptable fuel design limits and reactor coolant pressure boundary limits are not exceeded as a result of A00s or abnormal transients; and b.

Adequate core cooling is provided, and containment integrity and other vital functions are maintained in the event of a postulated DDA.

The DC electrical power requirements for MODES 4 and 5 are addressed in the Bases for LC0 3.8.5, "DC Sources-Shutdown."

(continued)

ABWR TS B 3.8-3 10/21/93

DC Sources-Operating B 3.8.4 BASES (continued)

ACTIONS A.l. A.2. A.3. A.4. and A.5 Condition A represents one of the Division I, II, or III DC electrical. power subsystems with a loss of ability to completely respond to an event, and a potential loss of ability to remain energized during normal operation.

It is, i

therefore, imperative that the operator's attention focus on stabilizing the unit, minimizing the potential for complete-loss of DC power to the affected division.

If Condition' A fi'ehtire~d',RiqU1Fid AiitiWC5 ~ill6si?72 hours8.333333e-4 days 0.02 hours 1.190476e-4 weeks 2.7396e-5 months to restore the inoperable DC electrical power ~'^ ~~

subsystem to,0PERABLE status,,provided the combustio5 turbine generator (CTG) is verified functional through testing within 12 hours1.388889e-4 days 0.00333 hours 1.984127e-5 weeks 4.566e-6 months and its capability of being aliinid to any of the three 6.9 kV essential AC buses 'is verified,'~

initially within 12 hours1.388889e-4 days 0.00333 hours 1.984127e-5 weeks 4.566e-6 months , and once per 8 hours9.259259e-5 days 0.00222 hours 1.322751e-5 weeks 3.044e-6 months thereafter*'

The functional capability of the, CTG is verified in this~~j Condition because the DC electrical power subsystem provi' dis control functions to the divisional DGs and the circuit ~~~ ~

breakers, RCIC(,Div., I), and other, loads. ^

^ ' '

If one of the required Division I, II, or III DC electrical power subsystems is inoperable (e.g., inoperable battery, inoperable battery charger, or inoperable battery charger and associated inoperable battery), the remaining DC electrical power subsystems have the capacity to support a safe shutdown and to mitigate an accident condition.

Since a subsequent worst case single failure could, however, result in the loss of minimum necessary DC electrical subsystems, conti_nued power operation should not exceed 721 hours0.00834 days 0.2 hours 0.00119 weeks 2.743405e-4 months .

The 72 hour8.333333e-4 days 0.02 hours 1.190476e-4 weeks 2.7396e-5 months Completion Time reflects a reasonable time to assess unit status as a function of the inoperable DC electrical power subsystem and, if the DC-electrical power subsystem is not restored to OPERABLE status, to prepare to effect an orderly and safe unit shutdown. The 72 hour8.333333e-4 days 0.02 hours 1.190476e-4 weeks 2.7396e-5 months limit is consistent with the allowed time for one DC distribution subsystem (either Division I, II, or III) being inoperable.

Completion of Required Action A.1 within 2 hours2.314815e-5 days 5.555556e-4 hours 3.306878e-6 weeks 7.61e-7 months provides further assurance that operation in Condition A for 72 hours8.333333e-4 days 0.02 hours 1.190476e-4 weeks 2.7396e-5 months is acceptable by determining that no common cause failure exist among the OPERABLE DC electrical power subsystems.

Because of its potential safety significance, only 2 hours2.314815e-5 days 5.555556e-4 hours 3.306878e-6 weeks 7.61e-7 months are allowed to verify that no common cause failure exists.

(continued)

ABWR TS B 3.8-4 10/21/93

DC Sources-Operating B 3.8.4 BASES (continued)

ACTIONS A.l. A.2. A.3. A.4. and A.5 (continued)

(continued)

Rsqu i?ed ? Acii bn1A!2? i s TspEEif fid Ts6sthilf appF6jifi s&sEf f6iis a re i i mpl eme n t ed li n tacco rd a n ce i Wi t. hit hej a f.fe c ted Requi rsdT ~

featdreslof t.C0/3.4j7sfor1RHRjShutdownjCooli.ngin] MODO 3]

i B.1 and B.2 In Condition B, Division IV DC electrical power subsystem is j

inoperable.

Required Actions B.1 and B.2 allow 12 hours1.388889e-4 days 0.00333 hours 1.984127e-5 weeks 4.566e-6 months to j

e.ffedt'sd : re.i th e r re s to refed ! fe a tu re s 11 no,pe,rabl _RAB thi.s.. subsystem. t.0 OPE i

a qui e?soith"stfappropriate

actionsDare? implemented;inLaccordance withitheraffected "

requi' red feat'urestofJtheMCOsVACTIONSi~ 'Dilision~IV~is less critical"than' ths'othiFthF e~DC~sls2tVical power subsystems because of its limited role in actuating safety related functions (i.e., Essential Multiplex System Div. IV, SSLC Div. IV sensor logic).

Division IV does not feed or control i

any major mechanical components or systems.

Therefore, its loss is not as critical as a loss of one of the other divisions, and the less restrictive ACTIONS of other LCOs are appropriate (iief,j.LC0f3E3.1. M C0:31353Q ).

C.1 and C.2 In Condition C, Division IV and one other DC electrical power subsystem are inoperable.

Because this condition is more severe than that of Condition A or B, only 2 hours2.314815e-5 days 5.555556e-4 hours 3.306878e-6 weeks 7.61e-7 months are allowed to restore one of the inoperable subsystems to OPERABLE status.

This 2 hour2.314815e-5 days 5.555556e-4 hours 3.306878e-6 weeks 7.61e-7 months Completion Time reflects a reasonable time to assess unit status as a function of the two inoperable DC electrical power subsystems and, if one of the DC electrical power subsystems is not restored to OPERABLE status, to prepare to effect an orderly and safe unit shutdown.

D.1 and 0.2 If all inoperable DC electrical power subsystems cannot be restored to OPERABLE status within the associated Completion Times for Required Actions A.1, B.2, and C.1 or C.2, the unit must be brought to a MODE in which the LCO does not apply.

To achieve this status, the plant must be brought to (continued)

ABWR TS B 3.8-5 10/21/93

~

DC Sources-Operating 8 3.8.4 BASES (continued)

ACTIONS D.1 and D.2 (continued)

(continued) at least MODE 3 within 12 hours1.388889e-4 days 0.00333 hours 1.984127e-5 weeks 4.566e-6 months and to MODE 4 within 36 hours4.166667e-4 days 0.01 hours 5.952381e-5 weeks 1.3698e-5 months .

The allowed Completion Times are reasonable, based on operating experience, to reach the required plant conditions from full power conditions in an orderly manner and without challenging plant systems. The Completion Time to bring the unit to MODE 4 is coasistent with the time required in Regulatory Guide 1.93 (Ref. 7).

SURVEILLANCE SR 3.8.4.1 REQUIREMENTS Verifying battery terminal voltage while on float charge helps to ensure the effectiveness of the charging system and the ability of the batteries to perform their intended function.

Float charge is the condition in which the charger is supplying the continuous charge required to overcome the internal losses of a battery (or battery cell) and maintain the battery (or battery cell) in a fully charged state.

The voltage requirements are based on the nominal design voltage of the battery and are consistent with the initial voltages assumed in the battery sizing calculations. The 7 day frequency is consistent with manufacturer's recommendations and IEEE-450 (Ref. 8).

Visual inspection to detect corrosion of the battery cells and connections, or measurement of the resistance'of each inter-cell, inter-rack, inter-tier, and terminal connection, provides an indication of physical damage or abnormal deterioration that could potentially degrade battery performance.

The limits established for this SR must be no more than 20%

above the resistance as measured during installation, or not above the ceiling value established by the manufacturer.

The Surveillance Frequency for these inspections, which can detect conditions that can cause power losses due to resistance heating, is 92 days.

This frequency is considered acceptable based on operating experience related to detecting corrosion trends.

(continued)

ABWR TS B 3.8-6 10/21/93

DC Sources-Operating -

B 3.8.4 BASES SR 3.8.4.3 7

Visual inspection of the battery cells, cell plates, and battery racks provides an indication of physical damage or abnormal deterioration that could potentially degrade battery performance.

The 12 month Frequency of these SRs is consistent with IEEE-450 (Ref. 8), which recommends detailed visual inspection of cell condition and inspection of cell to cell and terminal connection resistance on a yearly basis.

SR 3.8.4.4 and SR 3.8.4.5 Visual inspection and resistance measurements of inter-cell, inter-rack, inter-tier, and terminal connections provides an-indication of physical damage or abnormal deterioration that could indicate degraded battery condition.

The anti-corrosion material is used to ensure good electrical connections and to reduce terminal deterioration. The visual inspection for corrosion is not intended to require removal of and inspection under each terminal connection.

The removal of visible corrosion is a preventive maintenance SR. The presence of visible corrosion does not necessarily represent a failure of this SR, provided visible corrosion is removed during performance of this Surveillance.

The connection resistance limits for this SR must be no more than 20% above the resistance as measured during installation, or not above the ceiling value established by battery sizing.

The 12 month Frequency of these SRs is consistent with IEEE-450 (Ref. 8), which recommends detailed visual inspection of cell condition and inspection.of cell to cell and terminal connection resistance on a yearly basis.

SR 3.8.4.6 Battery charger capability requirements are based on the design capacity of the chargers (Ref. 4). According to Regulatory Guide 1.32 (Ref. 9), the battery charger supply is required to be based on the largest combined demands of (continued)

ABWR TS B 3.8-7 10/21/93

DC Sources-Operating B 3.8.4 BASES l

SURVEILLANCE SR 3.8.4.6 (continued)

REQUIREMENTS J

(continued) the various steady state loads and the charging capacity to restore the battery from the design minimum charge state to the fully charged state, irrespective of the status of the unit during these demand occurrences. The minimum required amperes and duration ensure that these requirements can be satisfied.

The Surveillance Frequency is acceptable, given the unit conditions required to perform the test and the other administrative controls existing to ensure adequate charger performance during these 18 month intervals.

In addition, this Frequency is intended to be consistent with expected fuel cycle lengths.

This SR is modified by two Notes.

The reason for Note 1 is that performing the Surveillance would remove a required DC electrical power subsystem from service, perturb the electrical distribution system, and challenge safety systems. Note 2 is added to this SR to acknowledge that credit may be taken for unplanned events that satisfy the Surveillance.

SR 3.8.4.7 A battery service test is a special test of the battery's capability, as found, to satisfy the design requirements (battery duty cycle) of the DC electrical power system.

The discharge rate and test length correspond to the design duty cycle requirements as specified in Reference 4.

The Surveillance Frequency of 18 months is consistent with the recommendations of Regulatory Guide 1.32 (Ref. 9) and Regulatory Guide 1.129 (Ref.10), which state that the battery service test should be performed during refueling operations or at some other outage, with intervals between tests not to exceed 18 months.

This SR is modified by three Notes. Note I allows a once per 60 months performance of a modified discharge test in lieu of a service test.

Typically, the modified discharge test is a simulated duty cycle consisting of just two rates; the one minute rate (continued)

ABWR TS B 3.8-8 10/21/93

i DC Sources-Operating B 3.8.4 BASES SURVEILLANCE SR 3.8.4.7 (continued)

REQUIREMENTS (continued) published for the battery or the largest current load of the duty cycle, followed by the test rate employed for the performance test.

Since the ampere-hours removed by a rated one minute discharge represents a very small portion of the battery's capacity, the test rate can be changed to that for the performance test without compromising the results of the performance test.

A modified discharge test is a test of the battery capacity and its ability to provide a high rate, short duration load (usually the highest rate of the duty cycle). This will often confirm the battery's ability to meet the critical period of the load duty cycle, in addition to determining its percentage of rated capacity.

Initial conditions for the modified performance test should be identical to those specified for a service test.

The reason for Note 2 is that performing the Surveillance would remove a required DC electrical power subsystem from service, perturb the electrical distribution system, and challenge safety systems.

Note 3 is added to this SR to acknowledge that credit may be taken for unplanned events that satisfy the Surveillance.

SR 3.8.4.8 A battery performance test is a test of constant current capacity of a battery, normally done in the as found condition, after having been in service, to detect any change in the capacity determined by the acceptance test.

The test is intended to determine overall battery degradation due to age and usage.

The acceptance criteria for this Surveillance is consistent with IEEE-450 (Ref. 8) and IEEE-485 (Ref. 11). These references recommend that the battery be replaced if its capacity is below 80% of the manufacturer's rating. A capacity of 80% shows that the battery rate of deterioration is increasing, even if there is ample capacity to meet the load requirements.

i (continued)-

t ABWR TS B 3.8-9 10/21/93 i

)

1 DC Sources-0perating B 3.8.4 BASES SURVEILLANCE SR 3.8.4.8 (continued)

REQUIREMENTS (continued)

The Surveillance Frequency for this test is 60 months, or every 12 months if the battery shows degradation or has reached 85% of its expected life. Degradation is indicated, according to IEEE-450 (Ref. 8), when the battery capacity drops by more than 10% relative to its capacity on the previous performance test or when it is 2 10% below the manufacturer's rating. All these Frequencies are consistent with the recommendations in IEEE-450 (Ref. 8).

This SP,is modified by two Notes. The reason for Note 1 is that performing the Surveillance would remove a required DC electrical power subsystem from service, perturb the electrical distribution system, and challenge safety systems.

Note 2 is added to this SR to acknowledge that t

credit may be taken for unplanned events that satisfy the Surveillance.

4 REFERENCES 1.

10 CFR 50, Appendix A, GDC 17.

i 2.

Regulatory Guide 1.6, March 10, 1971.

l l

3.

IEEE Standard 308, 1978.

l 4.

ABWR SSAR, Section 8.3.2.

5.

ABWR SSAR, Chapter 6.

l 6.

ABWR SSAR, Chapter 15.

l 7.

Regulatory Guide 1.93, December 1974.

[

8.

IEEE Standard 450, 1987.

9.

Regulatory Guide 1.32, February 1977.

l 10.

Regulatory Guide 1.129, December 1974.

11.

IEEE Standard 485, 1983.

12.

ABWR SSAR, Section 19E.2.1.2.2.

ABWR TS 8 3.8-10 10/21/93

\\

Inverters-Operating 3.8.7 3.8 ELECTRICAL POWER SYSTEMS 3.8.7 Inverters-0perating 1

LCO 3.8.7 The Division I, Division II, Division III, and Division IV inverters shall be OPERABLE.

APPLICABILITY:

MODES 1, 2, and 3.

i i

ACTIONS CONDITION REQUIRED ACTION COMPLETION TIME A.

One inverter

NOTE------------

inoperrble.

Immediately. enter applicable Conditions and Required Actions of LC0 3.8.9

" Distribution Systems -

.l Operating," for de-energized AC Vital buses.

A.1 Restore inverters to 7~?dsy"s

~~

OPERABLE status.

$$Q A?2T f 4TDeEIAFEIiffEE.fid 24..M6..i.ffs z-g

-~

jn.operablM ~ ' '

(continued)

ABWR TS 3,8-1 10/21/93

Inverters-Operating 3.8.7 ACTIONS (continued)

CONDITION REQUIRED ACTION COMPLETION TIME 949X E MF4NOTETs% G HEE immsdiatslyTsiitsshpplidabl{3 B.

One inverter (either Division I, II, e

or III) inoperable Cohditioijsgind!Redhir d"~~~

s AbtionsfofdCOI3!8f9 '

AND fDlstritidtio0{SfstEmsj@

Operatingifffohidssen&d"iiFd Division IV inverter AC Wi th11bu ssW~~~"~~~^'

"~

inoperable.

E+MO@jeffj{$fjn@G3 B.I Restore inoperable 2 hours2.314815e-5 days 5.555556e-4 hours 3.306878e-6 weeks 7.61e-7 months inverter (other than Division IV) to OPERABLE. status.

OB B.2 Restore Division IV 2 hours2.314815e-5 days 5.555556e-4 hours 3.306878e-6 weeks 7.61e-7 months inverter to OPERABLE status.

C.

Required Action and C.I Be in MODE 3.

12 hours1.388889e-4 days 0.00333 hours 1.984127e-5 weeks 4.566e-6 months associated Completion Time of Condition A, AND or B not met.

C.2 Be in MODE 4.

36 hours4.166667e-4 days 0.01 hours 5.952381e-5 weeks 1.3698e-5 months t

SURVEILLANCE REQUIREMENTS SURVEILLANCE FREQUENCY SR 3.8.7.I Verify correct inverter voltage, frequency, 7 days l

and alignment to required AC vital buses.

l ABWR TS 3.8-2 10/21/93 l

l l

I i

Inverters-Operating B 3.8.7 B 3.8 ELECTRICAL POWER SYSTEMS i

8 3.8.7 Inverters -0perating i

BASES BACKGROUND The inverters are the preferred source of power to the four AC vital buses. The inverter for each division is normally supplied power from the divisional 480 V AC motor control center (MCC) via an AC to DC rectifier.

Because there are only three divisions of 480 V AC divisional power, the l

Division IV inverter is powered by the Division II 480 V AC MCC via an AC to DC rectifier.

Each of the four divisions has access to its own Class IE 125 V battery that provides a backup source of 125 V DC power through a transfer switch.

The transfer switch automatically switches power from the AC to DC rectified normal power supply to the 125 V DC backup power supply when AC power failure is sensed (Ref. 1). The inverter converts DC electrical power to AC electrical power. The transfer switch and inverter thus provide an uninterruptible AC power supply for Class IE loads.

APPLICABLE The initial conditions of Design Basis Accident (DBA)

SAFETY ANALYSES and transient analyses in the SSAR, Chapter 6 (Ref. 2) and Chapter 15 (Ref. 3), assume Engineered Safety Feature systems are OPERABLE. The inverters are designed to provide the required capacity, capability, redundancy, and reliability to ensure the availability of necessary power to Class lE CVCF loads so that the fuel, Reactor Coolant System, and containment design limits are not exceeded.

These limits are discussed in more detail in the Bases for Section 3.2, Power Distribution Limits; Section 3.4, Reactor Coolant System (RCS); and Section 3.6, Containment Systems.

The OPERABILITY of the inverters is consistent with the initial assumptions of the accident analyses and is based on meeting the design basis of the unit.

This includes (continted)

ABWR TS B 3.8-1 10/21/93

4 Inverters -Operating B 3.8.7 BASES APPLICABLE maintaining electrical power sources OPERABLE during SAFETY ANALYSIS accident conditions in the event of:

(continued) a.

An assumed loss of all offsite AC or all onsite AC electrical power; and b.

A worst case single failure.

Inverters are a part of the distribution system and, as such, satisfy Criterion 3 of the NRC Policy Statement.

LCO The inverters ensure the availability of AC electrical power for the Class 1E CVCF loads required to shut down the reactor and maintain it in a safe condition after an anticipated operational occurrence (A00) or a postulated I

DBA.

l Maintaining the required inverters OPERABLE ensures that the redundancy incor lbgjEQQcphtFh]porated into the design of the RMSDrid PRM is maintained.

Ea W 6f t

l to ensure an uninterruptible supply of AC electrical power to the AC vital buses even if the 6.9 kV and 480 V safety buses are de-energized.

OPERABLE inverters require that the AC vital bus be powered l

by the inverter via an inverted DC voltage.

This assumes correct DC voltages are applied from the AC to DC rectified and 125 V DC power supplies, a correct AC voltage is at the

)

output, and these voltages are within the design voltage and 1

frequency tolerances.

If the vital AC bus is powered from the AC power supply through the 480.V/120 V bypass transformer, or power is available to the inverter from only its AC source, then the inverter is considered inoperable.

i j

(continued)

ABWR TS B 3.8-2 10/21/93

l Inverters-Operating B 3.8.7 BASES APPLICABILITY The inverters are required to be OPERABLE in MODES 1, 2, and 3 to ensure tnat:

a.

Acceptable fuel design limits and ' reactor coolant 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.

Inverter requirements for MODES 4 and 5 are covered in the Bases for LC0 3.8.8, " Inverters-Shutdown."

i ACTIONS A.l. A.2. B.l. and B.2 Even with a required inverter inoperable, the corresponding AC vital bus may not be inoperable. This would be the case if the AC vital bus is energized via its Class IE 480 V/120 V bypass transformer.

If the inoperability of an 3

inverter were to make an AC vital bus inoperable, the condition present would be more severe and would need to refer to another LC0 for appropriate action. Therefore, the Required Actions of Conditions A are modified by a Note stating that ACTIONS for LC0 3.8.9 must be entered i

immediately in the event an AC vital bus is de-energized, i.e., inoperable. This ensures the vital bus is returned to OPERABLE status within 729h'60H (or appropriate other i

ACTIONS are followed if'a5Tnierter and AC vital bus are inoperable).

Required Action A.1 allows Rdij~s.to fix the inoperable s

inverter and return it to sirvic ThanidsyMnifEiiiSnid

% E R Ed E M E G M T M EW 6d FA $ ad iEdlahd hieftsA~ ~ ~

schysia~ndMheitsg{ti6pTjjsslgajj6$$idMjpih'AC powertlyysM LCOs. When thi AC vitil Fus is powered from tie supply through its 480 V/120 V bypass transformer, it is relying upon interruptible AC electrical power sources (offsite and onsite). The uninterruptible, battery backed, inverter source to the AC vital buses is the preferred source for powering instrumentation trip ';ctpcint devices.

Action A.2 is specified so that appropriate restrictions are implemented in accordance with the affected required feature (s) of the LCOs' ACTIONS.

(continued)

ABWR TS B 3.8-3 10/21/93

Inverters-Operating B 3.8.7 BASES ACTIONS B.1 and B.2 (continued)

Even with1twocinverters anoperable, th _elcorrespondi_ng. LAC j:

vital buses 'may.not:be; inoperable; SThis?would$eithe cass 480 V/120:V bypassjtransformersb ;Ifsthelinoperabilityloffanl if' the'AC: vital l busest arennergized stattheir.lC1assp1Et J _.

inverter;weres to Lmake? an /A.Civitallbustinoperablegthe condition;presentnwouldybej.moresseveres:and;would need{.,to.

i refer?toyanother LC0.:xforlappropriatefactionclThereforeg,th,e~

Requ i red :: Act i on sw o fJ Cond i t i ont Blare t: mod i fi e'dj byf al Not.e statingithatLACTIONSffor7LCOL3;8,9);mustibe immedi ately $n (the f eventf anl ACi: vitals busti side;energ i.e.,finoperableveThisiensures3:theWital: bus:lisCreturne to OPERABLE? status. within !72thours:i(or;;appropriatenther" '~ ~ ~

ACTIONS are' followed if' the inverters;and :AC:lyitalibussfWs

~

inoperable).

In Condition B, the Division IV inverter and one other inverter are inoperable. Because this condition is more severe than that of Condition A, only 2 hours2.314815e-5 days 5.555556e-4 hours 3.306878e-6 weeks 7.61e-7 months are allowed to restore one of the inoperable inverters to OPERABLE status.

This 2 hour2.314815e-5 days 5.555556e-4 hours 3.306878e-6 weeks 7.61e-7 months Completion Time reflects a reasonable time to assess unit status as a function of the two inoperable inverters and, if one of the inverters is not restored to OPERABLE status, to prepare to effect an orderly and safe unit shutdown.

C.1 and C.2 If the inoperable devices or components cannot be restored to OPERABLE status within the associated Completion Time, the plant must be brought to a MODE in which the LC0 does not apply.

To achieve this status, the plant must be brought to at least MODE 3 within 12 hours1.388889e-4 days 0.00333 hours 1.984127e-5 weeks 4.566e-6 months and to MODE 4 within 36 hours4.166667e-4 days 0.01 hours 5.952381e-5 weeks 1.3698e-5 months . The allowed Completion Times are reasonable, based on operating experience, to reach the required plant conditions from full power conditions in an orderly manner and without challenging plant systems.

(continued)

ABWR TS B 3.8-4 10/21/93

. =.

Inverters-0perating B 3.8.7 BASES SURVEILLINCE SR 3.8.7.1 REQUIREMENTS This Surveillance verifies that the inverters are functioning properly with all required circuit breakers closed and AC vital buses energized from the inverter. The verification of proper voltage and frequency output ensures that the required power is readily available for the instrumentation connected to the AC vital buses. The 7 day Frequency takes into account the redundant capability of the inverters and other indications available in the control room that alert the operator to inverter malfunctions.

REFERENCES 1.

ABWR SSAR, Chapter 8.

2.

ABWR SSAR, Chapter 6.

3.

ABWR SSAR, Chapter 15.

i e

l ABWR TS B 3.8-5 10/21/93

-.

ML20059B626

Text

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