ML20094E663

Proposed Tech Specs,Proposing to Modify Post PCN-299 TS 3.8.1 to Extend Offsite Circuit AOT from 72 H & 6 Days from Discovery of Failure to Meet LCO

ML20094E663
Person / Time
Site:	San Onofre
Issue date:	11/02/1995
From:	SOUTHERN CALIFORNIA EDISON CO.
To:
Shared Package
ML20094E645	List: ML20094E641 ML20094E654 ML20094E663
References
NUDOCS 9511070347
Download: ML20094E663 (71)

Text

_ ._ _.

i AC Sources-Operating l 3.8.1 3.8 ELECTRICAL POWER SYSTEMS 3.8.1 AC Sources-0perating LCO 3.8.1 The following AC electrical sources shall be OPERABLE:

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

b. Two diesel generators (DGs) each capable of supplying one train of the onsite Class 1E AC Electrical Power Distribution System.

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

ACTIONS CONDITION REQUIRED ACTION COMPLETION TIME A. One required offsite A.1 Perform SR 3.8.1.1 1 hour1.157407e-5 days <br />2.777778e-4 hours <br />1.653439e-6 weeks <br />3.805e-7 months <br /> circuit inoperable. for required OPERABLE offsite circuit. AND Once per 8 hours9.259259e-5 days <br />0.00222 hours <br />1.322751e-5 weeks <br />3.044e-6 months <br /> thereafter AND A.2 Restore required 72 hours8.333333e-4 days <br />0.02 hours <br />1.190476e-4 weeks <br />2.7396e-5 months <br /> offsite circuit to .

OPERABLE status. AND I 6 days from discovery of failure to meet LC0 (continued)

SAN ONOFRE--UNIT 2 3.8-1 Amendment No. 02/28/95 l 9511070347 951102 PDR ADOCK 05000361 P PDR l l

AC Sources-Operating 3.8.1 4

ACTIONS (continued)

CONDITION REQUIRED ACTION COMPLETION TIME B. One required DG B.1 Perform SR 3.8.1.1 1 hour1.157407e-5 days <br />2.777778e-4 hours <br />1.653439e-6 weeks <br />3.805e-7 months <br />

. inoperable. for the OPERABLE required offsite AND circuits.

Once per 8 hours9.259259e-5 days <br />0.00222 hours <br />1.322751e-5 weeks <br />3.044e-6 months <br /> thereafter AND B.2 Declare required 4 hours4.62963e-5 days <br />0.00111 hours <br />6.613757e-6 weeks <br />1.522e-6 months <br /> from feature (s) supported discovery of by the inoperable DG Condition B inoperable when its concurrent with redundant required inoperability of feature (s) is redundant inoperable. required feature (s)

AND B.3.1 Determine OPERABLE DG 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br /> is not inoperable due to common cause failure.

OB 1

B.3.2 Perform SR 3.8.1.2 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br /> for OPERABLE DG.

AND B.4 Restore required DG 72 hours8.333333e-4 days <br />0.02 hours <br />1.190476e-4 weeks <br />2.7396e-5 months <br /> to OPERABLE status.

AND 6 days from discovery of failure to meet LC0 (continued)

SAN ON0FRE--UNIT 2 3.8-2 Amendment No. 02/28/95

AC Sources-Operating B 3.8.1 BASES ACTIONS A.2 (continued) systems. In this Condition, however, the remaining OPERABLE offsite circuit and DGs are adequate to supply electrical power to the onsite Class 1E Distribution System.

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

The second Completion Time for Required Action A.2 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 A is entered while, for instance, a DG is inoperable, and that DG is subsequently returned OPERABLE, the LCO may already have been not met for up to 72 hours8.333333e-4 days <br />0.02 hours <br />1.190476e-4 weeks <br />2.7396e-5 months <br />. This could lead to a total of 144 hours0.00167 days <br />0.04 hours <br />2.380952e-4 weeks <br />5.4792e-5 months <br />, since initial failure to meet the LCO, to restore the offsite circuit. At this time, a DG could again become inoperable, i the circuit restored OPERABLE, and an additional 72 hours8.333333e-4 days <br />0.02 hours <br />1.190476e-4 weeks <br />2.7396e-5 months <br /> (for a total of 9 days) allowed prior to complete restoration of the LCO. The 6 day Completion Time provides a limit on the time allowed in a specified condition after discovery of failure to meet the LCO. This limit is considered reasonable for situations in which Conditions A and B are entered concurrently. The "AND" connector between the 72 hour8.333333e-4 days <br />0.02 hours <br />1.190476e-4 weeks <br />2.7396e-5 months <br /> and 6 day Completion Time means that both Completion Times apply simultaneously, and the more restrictive Completion Time must be met.

As in Required Action A.2, the Completion Time allows for an exception to the normal " time zero" for beginning the allowed outage time " clock." This will result in establishing the " time zero" at the time that the LC0 was initially not met, instead of at the time Condition A was entered.

B.1 To ensure a highly reliable power source remains when one of the required DGs is inoperable, it is necessary to verify (continued)

SAN ON0FRE--UNIT 2 3.8-6 Amendment No. 02/28/95

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

According to Regulatory Guide 1.93 (Ref. 6), operation may continue in Condition B for a period that should" not exceed 72 hours8.333333e-4 days <br />0.02 hours <br />1.190476e-4 weeks <br />2.7396e-5 months <br />.

In Condition B, the remaining OPERABLE DG and offsite circuits are adequate to supply electrical power to the onsite Class 1E Distribution System. The 72 hour8.333333e-4 days <br />0.02 hours <br />1.190476e-4 weeks <br />2.7396e-5 months <br /> Completion Time takes into account the capacity and capability of the remaining AC sources, a reasonable time for repairs, and the low probability of a DBA occurring during this period.

The second Completion Time for Required Action B.4 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, an offsite circuit is inoperable and that circuit is subsequently returned OPERABLE, the LC0 may already have i been not met for up to 72 hours8.333333e-4 days <br />0.02 hours <br />1.190476e-4 weeks <br />2.7396e-5 months <br />. This could lead to a total of 144 hours0.00167 days <br />0.04 hours <br />2.380952e-4 weeks <br />5.4792e-5 months <br />, 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 72 hours8.333333e-4 days <br />0.02 hours <br />1.190476e-4 weeks <br />2.7396e-5 months <br /> (for a total of 9 days) allowed prior to complete restoration of the LCO. The 6 day Completion Time provides a limit on time allowed in a specified condition af ter discovery of failure to meet the LCO. This limit is i considered reasonable for situations in which Conditions A and B are entered concurrently. The "AND" connector between the 72 hour8.333333e-4 days <br />0.02 hours <br />1.190476e-4 weeks <br />2.7396e-5 months <br /> and 6 day Completion Times means that both Completion Times apply simultaneously, and the more restrictive Completion Time 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 time " clock." This will result in establishing the

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

(continued)

SAN ON0FRE--UNIT 2 3.8-9 Amendment No. 02/28/95

)

l AC Sources-Operating B 3.8.1 .

I BASES ACTIONS C.1 and C.2 (continued)

Required Action C.1, which applies when two offsite circuits are inoperable, is intended to provide assurance that an event with a coincident single failure will not result in a complete loss of redundant required safety functions. The l Completion Time for this failure of redundant required l features is reduced to 12 hours1.388889e-4 days <br />0.00333 hours <br />1.984127e-5 weeks <br />4.566e-6 months <br /> from the 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br /> allowed by I Regulatory Guide 1.93 (Ref. 6) for two inoperable required l offsite circuits. The 24 hour2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br /> allowance is based upon the i assumption that two complete safety trains are OPERABLE.

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

The Completion Time for Required Action C.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 Condition C (two offsite circuits inoperable) and a required feature becomes inoperable, this Completion Time begins to be tracked.

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

(continued)

SAN ONOFRE--UNIT 2 3.8-10 Amendment No. 02/28/95

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

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 level of degradation:

a. The configuration of the redundant AC electrical power system that remains available is not susceptible to a single bus or switching failure; and

b. The time required to detect and restore an unavailable 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 simultaneous 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 i analysis. Thus, the 24 hour2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br /> 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 Reference 6, with the available offsite AC sources two less than required by the LCO, operation may continue for 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br />. If two offsite sources are restored within 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br />, unrestricted operation may continue. If only one offsite source is restored within 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br />, power operation continues in accordance with Condition A. I D.1 and D.2 Pursuant to LC0 3.0.6, the Distribution System (LC0 3.8.9)

ACTIONS would not be entered even if all AC sources to it were inoperable resulting in de-energization. Therefore, the Required Actions of Condition D are modified by a Note (continued)

SAN ONOFRE--UNIT 2 3.8-11 Amendment No. 02/28/95

AC Sources -0perating B 3.8.1 BASES ACTIONS D.1 and D.2 (continued) l to indicate that when Condition D is entered, the Conditions and Required Actions for LC0 3.8.9, " Distribution Systems-0perating," must be immediately entered. This allows Condition D to provide requirements for the loss of one offsite circuit and one DG without regard to whether a train is de-energized. LC0 3.8.9 provides the appropriate restrictions for a de-energized train.

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

In Condition D, 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 C (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 <br />0.00333 hours <br />1.984127e-5 weeks <br />4.566e-6 months <br /> Completion Time takes into account the capacity and capability of the remaining AC sources, a reasonable time for repairs, and the low probability of a DBA occurring during this period.

E.1 With Train A and Train B DGs inoperable, there are no remaining standby AC sources. 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 this level of degradation, the risk associated with continued operation for a short time could be less than that associated with an immediate controlled shutdown (the immediate shutdown could cause grid instability, which could result in a total loss of AC power) . Since any inadvertent generator trip could also result in a total loss of offsite AC power, however, the time allowed for continued operation is severely restricted.

The intent here is to avoid the risk associated with an (continued)

SAN ONOFRE--UNIT 2 3.8-12 Amendment No. 02/28/95

AC Sources-Operating B 3.8.1 BASES ACTIONS E.1 (continued) immediate controlled shutdown and to minimize the risk associated with this level of degradation. l According to Reference 6, with both DGs inoperable, ,

operation may continue for a period that should not exceed l 2 hours2.314815e-5 days <br />5.555556e-4 hours <br />3.306878e-6 weeks <br />7.61e-7 months <br />.

1 F.1 and F.2 l If the inoperable AC electrical power sources cannot be restored to OPERABLE status within the required Completion Time, the unit must be brought to a MODE in which the LC0 i does not apply. To achieve this status, the unit must be  !

brought to at least MODE 3 within 6 hours6.944444e-5 days <br />0.00167 hours <br />9.920635e-6 weeks <br />2.283e-6 months <br /> and to MODE 5 ,

within 36 hours4.166667e-4 days <br />0.01 hours <br />5.952381e-5 weeks <br />1.3698e-5 months <br />. The allowed Completion Times are j reasonable, based on operating experience, to reach the required unit conditions from full power conditions in an orderly manner and without challenging unit systems.

Gd Condition G 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 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, Appendix A, GDC 18 (Ref. 8). Periodic component tests are supplemented by extensive functional tests during refueling outages (under simulated accident conditions).

The SRs for demonstrating the OPERABILITY of the DGs are in accordance with the recommendations of Regulatory Guide 1.9 (Ref. 3), Regulatory Guide 1.108 (Ref. 9), and Regulatory Guide 1.137 (Ref. 10).

(continued)

SAN ONOFRE--UNIT 2 3.8-13 Amendment No. 02/28/95

AC Sources-Operating B 3.8.1 BASES SURVEILLANCE Where the SRs discussed herein specify voltage and frequency REQUIREMENTS tolerances, the following is applicable. The minimum steady (continued) state output voltage of 3924 V is 90% of the nominal 4360 V output voltage. This value, which is consistent with ANSI C84.1-1982 (Ref. 11), allows for voltage drop to the terminals of 4000 V motors whose minimum operating voltage '

is specified as 90% or 3600 V. It also allows for voltage drops to motors and other equipment down through the 120 V level where minimum operating voltage is also usually specified as 80% of name plate rating. The specified maximum steady state output voltage of 4796 V allows for the maximum operating voltage specified for 4000 V motors. It ensures that for a lightly loaded distribution system, the voltage at the terminals of 4000 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 values are equal to 2% of the 60 Hz nominal frequency and are derived from the recommendations given in Regulatory Guide 1.9 (Ref. 3).

SR 3.8.1.1 This SR assures proper circuit continuity for the offsite AC electrical power supply to the onsite distribution network and availability of offsite AC electrical power. The breaker alignment verifies that each breaker is in its ,

correct position to ensure that distribution buses and loads  !

are connected to their preferred power source, and that 1 appropriate independence of offsite circuits is maintained, l 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 to maintain the unit in a safe shutdown condition. l To minimize the wear on moving parts that do not get lubricated when the engine is not running, these SRs are modified by a Note (Note 2 for SR 3.8.1.2) to indicate that l all DG starts for these Surveillances may be preceded by an l

(continued)

SAN ONCFRE--UNIT 2 3.8-14 Amendment No. 02/28/95

AC Sources-Operating l B 3.8.1 BASES SURVEILLANCE SR 3.8.1.2 and SR 3.8.1.7 (continued)

REQUIREMENTS engine prelube period and followed by a warmup period prior to loading.

For the purposes of SR 3.8.1.2 and SR 3.8.1.7 testing, the DGs are started from standby conditions. Standby conditions for a DG mean 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, the DG manufacturer recommends a modified start in which the starting speed of DGs is limited, warmup is limited to this lower speed, and the DGs are gradually accelerated to synchronous speed prior to loading. This is the intent of Note 3. I 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 10 seconds. The 10 second start requirement supports the assumptions of the design basis LOCA analysis in the UFSAR, Chapter 15 (Ref. 5).

The 10 second start requirement is not applicable to j SR 3.8.1.2 (see Note 3) when a modified start procedure as described above is used.

i Since SR 3.8.1.7 requires a 10 second start, it is more '

restrictive than SR 3.8.1.2 and it may be performed in lieu of SR 3.8.1.2. This 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," in the accompanying LCO) and the 184 day Frequency for SR 3.8.1.7 are consistent with Regulatory Guide 1.9 (Ref. 3). These Frequencies provide adequate assurance of DG OPERABILITY, while minimizing degradation resulting from testing.

SR 3.8.1.3 This Surveillance verifies that the DGs are capable of synchronizing with the offsite electrical system and accepting loads greater than or equal to the equivalent of (continued)

SAN ON0FRE--UNIT 2 3.8-15 Amendment No. 02/28/95

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

) AC Sources-Operating B 3.8.1 j

BASES l 4 1

] SURVE1LLANCE SR 3.8.1.3 (continued) )

i REQUIREMENTS i the maximum expected accident loads listed in Reference 2. )

! A minimum run time of 60 minutes is required to stabilize engine temperatures, while minimizing the time that the DG j

is connected to the offsite source. l 1 Although no power factor requirements are established by  ;

this SR, the DG is normally operated at a power factor i between 0.8 lagging and 1.0. The 0.8 value is the design j rating of the machine, while 1.0 is an operational j limitation to ensure circulating currents are minimized.  ;

i  !

l The normal 31 day Frequency for this Surveillance l 1 (Table 3.8.1-1) is consistent with Regulatory Guide 1.9 i (Ref.3).

! 1 This SR is modified by four Notes. Note 1 indicates 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. Note 2 states that momentary transients because of changing bus loads do not invalidate this test.

Similarly, momentary power factor transients above the limit will not invalidate the 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. Note 4 stipulates a  ;

prerequisite requirement for performance of this SR. A successful DG start must precede this test to credit satisfactory performance. i l

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 selected to ensure 1 adequate fuel oil for a minimum of 1 hour1.157407e-5 days <br />2.777778e-4 hours <br />1.653439e-6 weeks <br />3.805e-7 months <br /> of DG operation at '

full load plus 10%. The level is expressed as an equivalent volume in inches. The 30 inch level corresponds to 355.1 gallons of fuel oil including instrument uncertainties.

The 31 day Frequency is adequate to assure that a sufficient )

supply of fuel oil is available, since low level alarms are (continued)

SAN ON0FRE--UNIT 2 3.8-16 Amendment No. 02/28/95

AC Sources-Operating B 3.8.1 BASES SURVEILLANCE SR 3.8.1.4 (continued)

REQUIREMENTS provided and unit 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 microorganisms 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 microbial survival in the day tanks. This is the most effective means of 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 from breakdown of the fuel oil by microorganisms. Frequent checking for and removal 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. 10). This SR is for preventive maintenance. The presence of water does not necessarily represent failure of this SR provided the accumulated water is removed during the performance of this Surveillance.

l SR 3.8.1.6 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. This is '

required to support continuous operation of standby power l 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 i controls and control systems for automatic fuel transfer systems are OPERABLE. l The design of fuel transfer systems is such that pumps will operate automatically or must be started manually in order (continued)

SAN ONOFRE--UNIT 2 3.3-17 Amendment No. 02/28/95

l AC Sources-Operating B 3.8.1 BASES SURVEILLANCE SR 3.8.1.6 (continued)

REQUIREMENTS 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.

SR 3.8.1.7 See SR 3.8.1.2.

SR 3.8.1.8 i

Transfer of each 4.16 kV ESF bus power supply from the normal offsite circuit to the alternate offsite circuit demonstrates the OPERABILITY of the alternate circJit distribution network to power the shutdown loads. The 1 24 month Frequency of the Surveillance is based on engineering Judgment, taking into consideration the unit i 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 24 month Frequency Therefore, the Frec uency was concluded to be acceptable from a reliability stanc point.

This SR is modified by a Note which acknowledges that credit may be taken for unplanned events that satisfy this SR.

\

\

SR 3.8.1.9 Each DG is )rovided with an engine overspeed trip to prevent damage to tie 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 l the engine. This Surveillance demonstrates the DG load ,

response characteristics and capability to reject the l largest single load without exceeding predetermined voltage i and frequency and while maintaining a specified margin to l the overspeed trip. For this unit, the single load for each DG is the Auxiliary Feedwater pump and its horse)ower rating is 800 HP. As required by IEEE-308 (Ref.13), tie load rejection test is acceptable if the increase in diesel speed does not exceed 75% of the difference between synchronous (continued)

SAN ONOFRE--UNIT 2 3.8-18 Amendment No. 02/28/95 l

AC Sources -0perating B 3.8.1 l

BASES j SURVEILLANCE SR 3.8.1.9 (continued).

REQUIREMENTS i speed and the overspeed trip setpoint, or 15% above synchronous speed, whichever is lower.

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

The 4 seconds specified is equal to 80% of a typical 5 second load sequence interval associated with sequencing of the 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 i system must recover following load rejection. The 24 month Frequency is consistent with the recommendation of Regulatory Guide 1.9 (Ref. 3).

In order to ensure that the DG is tested under load conditions that are as close to design basis conditions as possible, testing is performed using design basis kW ioading and maximum kVAR loading permitted during testing. These loadings represent the inductive loading that the DG would experience to the extent practicable and is consistent with  !

the intent of Regulatory Guide 1.9 (Ref. 3). -

This SR is modified by a Note which acknowledges that credit  !

may be taken for unplanned events that satisfy this SR.

SR 3.8.1.10 This Surveillance demonstrates the DG capability to reject a load equal to 94.5% to 100% of its continuous rating without 1 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 ensure proper engine generator load response under the simulated test conditions. This test simulates i the loss of the total connected load that the DG experiences i following a full load rejection and verifies that the DG will not trip upon loss of the load. These acceptance  !

criteria provide DG damage protection. While the DG is not i expected to experience this transient during an event and )

(continued)

SAN ON0FRE--UNIT 2 3.8-19 Amendment No. 02/28/95

AC Sources-0perating B 3.8.1 BASES j l

SURVEILLANCE SR 3.8.1.10 (continued) {

REQUIREMENTS 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. These loads and limits are consistent with Regulatory Guide 1.9 (Ref. 3). In order to ensure that the DG is tested under load conditions that are as close to design basis conditions as possible, testing is performed using design basis kW loading and maximum kVAR loading permitted during testing. These loadings represent the inductive ioading that the DG would experience to the extent pract' cable and is consistent with the intent of Regulatory Guide 1.9 (Ref. 3).

The 24 month Frequency is consistent with the recommendation of Regulatory Guide 1.9 (Ref. 3) and is intended to be consistent with expected fuel cycle lengths.

This SR is modified by a Note which acknowledges that credit may be taken for unplanned events that satisfy this SR.

SR 3.8.1.11 As required by Regulatory Guide 1.9 (Ref. 3), this Surveillance demonstrates the as designed operation of the standby power sources during loss of the offsite source.

This test verifies all actions encountered from the loss of offsite power, including shedding of the nonessential loads and energization of the emergency buses and respective loads from the DG. It further demonstrates the capability of the DG to automatically achieve the required voltage and frequency within the specified time.

The DG auto-start time of 10 seconds is derived from requirements of the accident analysis to respond to a design basis large break LOCA. The frequency should be restored to within 2% of nominal 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 loads is intended to satisfactorily show the (continued)

SAN ON0FRE--UNIT 2 3.8-20 Amendment No. 02/28/95

AC Sources-Operating l 8 3.8.1 '

BASES SURVEILLANCE SR 3.8.1.11 (continued)

REQUIREMENTS relationship of these loads to the 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, Emergency Core Cooling Systems (ECCS) injection valves are not desired to be stroked open, high pressure injection systems are not capable of being operated at full flow, or shutdown cooling (SDC) 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 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 24 months is consistent with the recommendations of Regulatory Guide 1.9 (Ref. 3), takes into consideration unit conditions 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 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 continuously circulated and temperature maintained consistent with manufacturer recommendations. Note 2 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 volta within the specified time (10 seconds)ge fromand the frequency design basis actuation signal and operates for a 5 minutes. The 5 minute period provides sufficient time to demonstrate stability.

(continued)

SAN ON0FRE--UNIT 2 3.8-21 Amendment No. 02/28/95 J

AC Sources-0perating B 3.8.1 BASES.

REFERENCES 5. UFSAR, Chapter 15.

(continued)

6. Regulatory Guide 1.93, Rev. O.

7. Generic Letter 84-15.

8. 10 CFR 50, Appendix A, GDC 18.

9. Regulatory Guide 1.108, Rev. 1.

10. Regulatory Guide 1.137, Rev. 1.

11. ANSI C84.1-1982.

12. ASME, Boiler and Pressure Vessel Code,Section XI.

13. IEEE Standard 308-1978.

14. Draft Regulatory Guide DG-1021, April 1992.

15. 10 CFR 50.63(a)(3)(ii) as published in Federal Register Vol . 57, No. 77 page 14517, April 21,1992.

SAN ON0FRE--UNIT 2 3.8-29 Amendment No. 02/28/95

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

ATTACHMENT "B" POST PCN-299 (TECHNICAL SPECIFICATION IMPROVEMENT PROGRAM) SPECIFICATIONS UNIT 3 l

l 1

4 l

a l AC Sources-Operating

3.8.1 i

! 3.8 ELECTRICAL POWER SYSTEMS  !

l 3.8.1 AC Sources-Operating i

i

{ LC0 3.8.1 The following AC electrical sources shall be OPERABLE: i Two qualified circuits between the offsite transmission a.

network and the onsite Class 1E AC Electrical Power Distribution System; and

b. Two diesel generators (DGs) each capable of supplying  ;

one train of the onsite Class 1E AC Electrical Power <

Distribution System.

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

ACTIONS CONDITION REQUIRED ACTION COMPLETION TIME A. One required offsite A.1 Perform SR 3.8.1.1 1 hour1.157407e-5 days <br />2.777778e-4 hours <br />1.653439e-6 weeks <br />3.805e-7 months <br /> circuit inoperable. for required OPERABLE offsite circuit. AND Once per 8 hours9.259259e-5 days <br />0.00222 hours <br />1.322751e-5 weeks <br />3.044e-6 months <br /> thereafter AND A.2 Restore required 72 hours8.333333e-4 days <br />0.02 hours <br />1.190476e-4 weeks <br />2.7396e-5 months <br /> offsite circuit to OPERABLE status. AND 6 days from discovery of failure to meet LC0 (continued) l l

SAN ON0FRE--UNIT 3 3.8-1 Amendment No. 02/28/95 l i

I l AC Sources-Operating 3.8.1 1

4 j ACTIONS (continued) l CONDITION REQUIRED ACTION COMPLETION TIME 1

B. One required DG B.1 Perform SR 3.8.1.1 1 hour1.157407e-5 days <br />2.777778e-4 hours <br />1.653439e-6 weeks <br />3.805e-7 months <br /> l inoperabl e. for the OPERABLE i i

required offsite AND l circuits. 1 Once per 8 hours9.259259e-5 days <br />0.00222 hours <br />1.322751e-5 weeks <br />3.044e-6 months <br /> I thereafter l AND B.2 Declare required 4 hours4.62963e-5 days <br />0.00111 hours <br />6.613757e-6 weeks <br />1.522e-6 months <br /> from feature (s) supported discovery of by the inoperable DG Condition B inoperable when its concurrent with I redundant required inoperability of feature (s) is redundant inoperable. required feature (s)

AND B.3.1 Determine OPERABLE DG 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br /> is not inoperable due 4

to common cause failure.

0_.B B.3.2 Perform SR 3.8.1.2 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br /> .

for OPERABLE DG.

AND B.4 Restore required DG 72 hours8.333333e-4 days <br />0.02 hours <br />1.190476e-4 weeks <br />2.7396e-5 months <br /> to OPERABLE status.

AND 6 days from discovery of failure to meet LC0 (continued)

SAN ON0FRE--UNIT 3 3.8-2 Amendment No. 02/28/95 l

1 l

AC Sources-Operating B 3.8.1 BASES ACTIONS A.2 (continued) i systems. In this Condition, however, the remaining 0PERABLE offsite circuit and DGs are adequate to supply electrical power to the onsite Class 1E Distribution System.

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

I The second Completion Time for Required Action A.2 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 A is entered while, for instance, a DG is inoperable, and that DG is subsequently returned OPERABLE, the LC0 may already have been not met for up to 72 hours8.333333e-4 days <br />0.02 hours <br />1.190476e-4 weeks <br />2.7396e-5 months <br />. This could lead to a total of 144 hours0.00167 days <br />0.04 hours <br />2.380952e-4 weeks <br />5.4792e-5 months <br />, since initial failure to meet the LCO, to restore the offsite circuit. At this time, a DG could again become inoperable, the circuit restored OPERABLE, and an additional 72 hours8.333333e-4 days <br />0.02 hours <br />1.190476e-4 weeks <br />2.7396e-5 months <br /> (for a total of 9 days) allowed prior to complete restoration of the LCO. The 6 day Completion Time provides a limit on the time allowed in a specified condition after l discovery of failure to meet the LCO. This limit is considered reasonable for situations in which Conditions A and B are entered concurrently. The "AND" connector between l the 72 hour8.333333e-4 days <br />0.02 hours <br />1.190476e-4 weeks <br />2.7396e-5 months <br /> and 6 day Completion Time means that both Completion Times apply simultaneously, and the more l restrictive Completion Time must be met.

1 As in Required Action A.2, the Completion Time allows for an l exception to the normal " time zero" for beginning the

allowed outage time " clock." This will result in

! establishing the " time zero" at the time that the LCO was l- initially not met, instead of at the time Condition A was

entered.

i B.1 To ensure a highly reliable power source remains when one of the required DGs is inoperable, it is necessary to verify i

i

! (continued)

SAN ON0FRE--UNIT 3 3.8-6 Amendment No. 02/28/95

1 AC Sources-Operating B 3.8.1 BASES ACTIONS B.4 (continued)

According to Regulatory Guide 1.93 (Ref. 6), operation may continue in Condition B for a period that should not exceed 72 hours8.333333e-4 days <br />0.02 hours <br />1.190476e-4 weeks <br />2.7396e-5 months <br />.

In Condition B, the remaining OPERABLE DG and offsite circuits are adequate to supply electrical power to the onsite Class 1E Distribution System. The 72 hour8.333333e-4 days <br />0.02 hours <br />1.190476e-4 weeks <br />2.7396e-5 months <br /> Completion Time takes into account the capacity and capability of the remaining AC sources, a reasonable time for repairs, and the low probability of a DBA occurring during this period.

The second Completion Time for Required Action B.4 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, an offsite circuit is inoperable and that circuit is subsequently returned OPERABLE, the LC0 may already have been not met for up to 72 hours8.333333e-4 days <br />0.02 hours <br />1.190476e-4 weeks <br />2.7396e-5 months <br />. This could lead to a total j of 144 hours0.00167 days <br />0.04 hours <br />2.380952e-4 weeks <br />5.4792e-5 months <br />, 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 72 hours8.333333e-4 days <br />0.02 hours <br />1.190476e-4 weeks <br />2.7396e-5 months <br /> (for a total of 9 days) allowed prior to complete restoration of the LCO. The 6 day Completion Time provides a limit on time allowed in a specified condition after discovery of failure to meet the LCO. This limit is considered reasonable for situations in which Conditions A and B are entered concurrently. The "AND" connector between the 72 hour8.333333e-4 days <br />0.02 hours <br />1.190476e-4 weeks <br />2.7396e-5 months <br /> and 6 day Completion Times means that both Completion Times apply simultaneously, and the more restrictive Completion Time 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 time " clock." This will result in establishing the

" time zero" at the time that the LCO was initially not met, instead of at the time Condition B was entered.

(continued) i SAN ONOFRE--UNIT 3 3.8-9 Amendment No. 02/28/95

AC Sources-0perating B 3.8.1 BASES ACTIONS C.1 and C.2 (continued)

Required Action C.1, which applies when two offsite circuits are inoperable, is intended to provide assurance that an event with a coincident single failure will not result in a complete loss of redundant required safety functions. The Completion Time for this failure of redundant required features is reduced to 12 hours1.388889e-4 days <br />0.00333 hours <br />1.984127e-5 weeks <br />4.566e-6 months <br /> from the 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br /> allowed by Regulatory Guide 1.93 (Ref. 6) for two inoperable required offsite circuits. The 24 hour2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br /> allowance is based upon the assumption that two complete safety trains are OPERABLE.

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

The Completion Time for Required Action C.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 Condition C (two offsite circuits inoperable) and a required feature becomes inoperable, this Completion Time begins to be tracked.

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

i (continued)

SAN ON0FRE--UNIT 3 3.8-10 Amendment No. 02/28/95

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

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 level of degradation:

a. The configuration of the redundant AC electrical power system that remains available is not susceptible to a single bus or switching failure; and

b. The time required to detect and restore an unavailable 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 L unit in a safe shutdown condition in the event of a DBA or transient. In fact, a simultaneous loss of offsite AC 5 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 <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br /> 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 cri teria.

According to Reference 6, with the available offsite AC sources two less than required by the LCO, operation may continue for 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br />. If two offsite sources are restored within 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br />, unrestricted operation may continue. If only one offsite source is restored within 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br />, power  !

operation continues in accordance with Condition A.

1 i

D.1 and D.2 l Pursuant to LC0 3.0.6, the Distribution System (LC0 3.8.9) l ACTIONS would not be entered even if all AC sources to it '

were inoperable resulting in de-energization. Therefore, I the Required Actions of Condition D are modified by a Note (continued) l SAN ON0FRE--UNIT 3 3.8-11 Amendment No. 02/28/95 j

AC Sources-Operating B 3.8.1 BASES ACTIONS D.1 and D.2 (continued) to indicate that when Condition D is entered, the Conditions and Required Actions for LC0 3.8.9, " Distribution Systems-Operating," must be immediately entered. This allows Condition D to provide requirements for the loss of one offsite circuit ar.t.i one DG without regard to whether a train is de-energized. LC0 3.8.9 provides the appropriate restrictions for a de-energized train.

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

In Condition D, 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 C (loss of both required offsite circuits). This difference in reliability is offset by the f

susceptibility of this power system configuration to a single bus or switching failure. The 12 hour1.388889e-4 days <br />0.00333 hours <br />1.984127e-5 weeks <br />4.566e-6 months <br /> Completion Time takes into account the capacity and capability of the remaining AC sources, a reasonable time for repairs, and the low probability of a DBA occurring during this period.

E.1 With Train A and Train B DGs inoperable, there are no remaining standby AC sources. 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 this level of degradation, the risk associated with continued operation for a short time could be less than that associated with an immediate controlled shutdown (the immediate shutdown could cause grid instability, which could result in a total loss of AC power) . Since any inadvertent generator trip could also result in a total loss of offsite AC power, however, the time allowed for continued operation is severely restricted.

The intent here is to avoid the risk associated with an (continued) l SAN ONOFRE--UNIT 3 3.8-12 Amendment No. 02/28/95 l I

AC Sources-0perating

\ B 3.8.1 BASES ACTIONS E.1 (continued) immediate controlled shutdown and to minimize the risk associated with this level of degradation.

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

F.1 and F.2 If the inoperable AC electrical power sources cannot be restored to OPERABLE status within the required Completion 3'

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 at least MODE 3 within 6 hours6.944444e-5 days <br />0.00167 hours <br />9.920635e-6 weeks <br />2.283e-6 months <br /> and to MODE 5 within 36 hours4.166667e-4 days <br />0.01 hours <br />5.952381e-5 weeks <br />1.3698e-5 months <br />. The allowed Completion Times are reasonable, based on operating experience, to reach the required unit conditions from full power conditions in an

orderly manner and without challenging unit systems.

V G.1 Condition G 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 l function. Therefore, no additional time is justified for continued operation. The unit is required by LC0 3.0.3 to commence a controlled shutdown.

i SURVEILLANCE The AC sources are designed to permit inspection and REQUIREMENTS testing of all important areas and features, especially i those that have a standby function, in accordance with 10 CFR 50, Appendix A, GDC 18 (Ref. 8). Periodic component tests are supplemented by extensive functional tests during refueling outages (under simulated accident conditions).

The SRs for demonstrating the OPERABILITY of the DGs are in '

accordance with the recommendations of Regulatory Guide 1.9 (Ref. 3), Regulatory Guide 1.108 (Ref. 9), and Regulatory Guide 1.137(Ref.10).

(continued)

SAN ON0FRE--UNIT 3 3.8-13 Amendment No. 02/28/95

1 AC Sources-0perating B 3.8.1 BASES 1

SURVEILLANCE Where the SRs discussed herein specify voltage and frequency REQUIREMENTS tolerances, the following is applicable. The minimum steady (continued) state output voltage of 3924 V is 90% of the nominal 4360 V output voltage. This value, which is consistent with ANSI C84.1-1982 (Ref. 11), allows for voltage drop to the terminals of 4000 V motors whose minimum operating voltage is specified as 90% or 3600 V. It also allows for voltage drops to motors and other equipment down through the 120 V level where minimum operating voltage is also usually specified as 80% of name plate rating. The specified maximum steady state output voltage of 4796 V allows for the maximum operating voltage specified for 4000 V motors. It ensures that for a lightly loaded distribution system, the voltage at the terminals of 4000 V motors is no more than i the maximum rated operating voltages. The specified minimum i

and maximum frequencies of the DG are 58.8 Hz and 61.2 Hz, respectively. These values are equal to 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 assures proper circuit continuity for the offsite AC l electrical power supply to the onsite distribution network and availability of offsite AC electrical power. The l breaker alignment verifies that each breaker is in its I correct position to ensure that distribution buses and loads l are connected to their preferred power source, and that l appropriate independence of offsite circuits is maintained.

l 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 1 l

These SRs help to ensure the availability of the standby  !

electrical power supply to mitigate DBAs and transients and to maintain the unit in a safe shutdown condition.

l To minimize the wear on moving parts that do not get lubricated when the engine is not running, these SRs are l modified by a Note (Note 2 for SR 3.8.1.2) to indicate that

all DG starts for these Surveillances may be preceded by an (continued)

SAN ON0FRE--UNIT 3 3.8-14 Amendment No. 02/28/95

l AC Sources-Operating i

B 3.8.1 BASES SURVEILLANCE SR 3.8.1.2 and SR 3.8.1.7 (continued)

REQUIREMENTS engine prelube period and followed by a warmup period prior to loading.  !

For the purposes of SR 3.8.1.2 and SR 3.8.1.7 testing, the DGs are started from standby conditions. Standby conditions for a DG mean the diesel engine coolant and oil are being i continuously circulated and temperature is being maintained  !

consistent with manufacturer recommendations.

In order to reduce stress and wear on diesel engines, the DG manufacturer recommends a modified start in which the  !

starting speed of DGs is limited, warmup is limited to this lower speed, and the DGs are gradually accelerated to synchronous speed prior to loading. This is the intent of Note 3.

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 10 seconds. The 10 second start requirement supports the assumptions of the design basis  ;

LOCA analysis in the UFSAR, Chapter 15 (Ref. 5).

The 10 second start requirement is not applicable to SR 3.8.1.2 (see Note 3) when a modified start procedure as described above is used.

Since SR 3.8.1.7 requires a 10 second start, it is more l restrictive than SR 3.8.1.2 and it may be performed in lieu of SR 3.8.1.2. This 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," in the accompanying LCO) and the 184 day Frequency for SR 3.8.1.7 are consistent with Regulatory Guide 1.9 (Ref. 3). These Frequencies provide adequate assurance of DG OPERABILITY, while minimizing degradation resulting from testing.

SR 3.8.1.3 This Surveillance verifies that the DGs are capable of synchronizing with the offsite electrical system and accepting loads greater than or equal to the equivalent of (continued)

SAN ON0FRE--UNIT 3 3.8-15 Amendment No. 02/28/95

AC Sources-Operating B 3.8.1 BASES SURVEILLANCE SR 3.8.1.3 (continued)

REQUIREMENTS the maximum expected accident loads listed in Reference 2.

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.

Although no power factor requirements are established by this SR, the DG is normally operated at a power factor between 0.8 lagging and 1.0. The 0.8 value is the design rating of the machine, while 1.0 is an operational limitation to ensure circulating currents are minimized.

The normal 31 day Frequency for this Surveillance (Table 3.8.1-1) is consistent with Regulatory Guide 1.9 (Ref.3).

This SR is modified by four Notes. Note 1 indicates 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. Note 2 states that momentary transients because of changing bus loads do not invalidate this test.

Similarly, momentary power factor transients above the limit will not invalidate the 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. 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 selected to ensure I adequate fuel oil for a minimum of 1 hour1.157407e-5 days <br />2.777778e-4 hours <br />1.653439e-6 weeks <br />3.805e-7 months <br /> of DG operation at i full load plus 10%. The level is expressed as an equivalent i volume in inches. The 30 inch level corresponds to 355.1 gallons of fuel oil including instrument uncertainties.

The 31 day Frequency is adequate to assure that a sufficient supply of fuel oil is available, since low level alarms are (continued) l SAN ON0FRE--UNIT 3 3.8-16 Amendment No. 02/28/95 i

AC Sources-Operating B 3.8.1 BASES SURVEILLANCE SR 3.8.1.4 (continued)

REQUIREMENTS provided and unit 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 microorganisms 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 microbial survival in the day tanks. This is the most effective means of 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 from breakdown of the fuel oil by microorganisms. Frequent checking for and removal of accumulated water minimizes fouling and provides data regarding the watertight integrity of the fuel oil system. l The Surveillance Frequencies are established by Regulatory i Guide 1.137 (Ref. 10). This SR is for preventive  !

maintenance. The presence of water does not necessarily )

represent failure of this SR provided the accumulated water is removed during the performance of this Surveillance, l

SR 3.8.1.6 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. This is required to support 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.

l The design of fuel transfer systems is such that pumps will operate automatically or must be started manually in order (continued)

SAN ON0FRE--UNIT 3 3.8-17 Amendment No. 02/28/95

AC Sources-Operating B 3.8.1 BASES SURVEILLANCE SR 3.8.1.6 (continued)

REQUIREMENTS 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.

SR 3.8.1.7 See SR 3.8.1.2.

SR 3.8.1.8 Transfer of each 4.16 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 power the shutdown loads. The 24 month Frequency of the Surveillance is based on engineering judgment, taking into consideration the unit conditions required to perform the Surveillance, and is intended to be consistent with expected fuel cycle lengths.

Operating experience has shown that f.hese components usually pass the SR when performed at the 24 month Frequency Therefore, the Frecuency was conclude,i to be acceptable from a reliability stanc point.

This SR is modified by a Note which acknowledges that credit may be taken for unplanned events that satisfy this SR.

SR 3.8.1.9 Each DG is arovided with an engine overspeed trip to prevent damage to tie 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. For this unit, the single load for each DG is the Auxiliary Feedwater pump and its horse 3ower rating is 800 HP. As required by IEEE-308 (Ref. 13), t1e load rejection test is acceptable if the increase in diesel speed does not exceed 75% of the difference between synchronous (continued)

SAN ON0FRE--UNIT 3 3.8-18 Amendment No. 02/28/95

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

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

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

The 4 seconds specified is equal to 80% of a typical 5 second load sequence interval associated with sequencing of the 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 24 month j Frequency is consistent with the recommendation of Regulatory Guide 1.9 (Ref. 3).

In order to ensure that the DG is tested under load conditions that are as close to design basis conditions as i possible, testing is performed using design basis kW loading I and maximum kVAR loading permitted during testing. These loadings represent the inductive loading that the DG would i experience to the extent practicable and is consistent with the intent of Regulatory Guide 1.9 (Ref. 3).

This SR is modified by a Note which acknowledges that credit l may be taken for unplanned events that satisfy this SR.

SR 3.8.1.10 This Surveillance demonstrates the DG capability to reject a load equal to 94.5% to 100% of its continuous rating 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 will 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 (continued)

SAN ONOFRE--UNIT 3 3.8-19 Amendment No. 02/28/95

4

! AC Sources-Operating j B 3.8.1 l

2 BASES j SURVEILLANCE SR 3.8.1.10 (continued)

REQUIREMENTS continues to be available, this response ensures that the DG j is not degraded for future application, including )

reconnection to the bus if the trip initiator can be corrected or isolated. These loads and limits are consistent with Regulatory Guide 1.9 (Ref. 3). In order to

{ ensure that the DG is tested under load conditions that are as close to design basis conditions as possible, testing is 4

performed using design basis kW loading and maximum kVAR loading permitted during testing. These loadings represent a the inductive loading that the DG would experience to the i extent practicable and is consistent with the intent of l Regulatory Guide 1.9 (Ref. 3). 1 1

l The 24 month Frequency is consistent with the recommendation l l of Regulatory Guide 1.9 (Ref. 3) and is intended to be  ;

consistent with expected fuel cycle lengths. I This SR is modified by a Note which acknowledges that credit may be taken for unplanned events that satisfy this SR.

SR 3.8.1.11 As required by Regulatory Guide 1.9 (Ref. 3), this Surveillance demonstrates the as designed operation of the standby power sources during loss of the offsite source.

This test verifies all actions encountered from the loss of offsite power, including shedding of the nonessential loads and energization of the emergency buses and respective loads from the DG. It further demonstrates the capability of the DG to automatically achieve the required voltage and frequency within the specified time.

The DG auto-start time of 10 seconds is derived from requirements of the accident analysis to respond to a design i basis large break LOCA. The frequency should be restored to '

within 2% of nominal 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 i decayed and stability has been achieved.

The requirement to verify the connection and power supply of )

permanent loads is intended to satisfactorily show the (continued)

SAN ONOFRE--UNIT 3 3.8-20 Amendment No. 02/28/95

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

REQUIREMENTS relationship of these loads to the 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, Emergency Core Cooling Systems (ECCS) injection valves are not desired to be stroked open, high pressure injection systems are not capable of being operated at full flow, or shutdown cooling (SDC) 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 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 24 months is consistent with the recommendations of Regulatory Guide 1.9 (Ref. 3), takes into consideration unit conditions 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 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 continuously circulated and temperature maintained consistent with manufacturer recommendations. Note 2 acknowledges that credit may be taken for unplanned events that satisfy this SR.

l SR 3.8.1.12 This Surveillance demonstrates that the DG automatically starts and achieves the required voltage and frequency within the specified time (10 seconds) from the design basis ,

actuation signal and operates for a 5 minutes. The 5 minute period provides sufficient time to demonstrate stability.

(continued)

SAN ON0FRE--UNIT 3 3.8-21 Amendment No. 02/28/95

AC Sources-0perating B 3.8.1 BASES REFERENCES 5. UFSAR, Chapter 15.

(continued)

6. Regulatory Guide 1.93, Rev. O.

7. Generic Letter 84-15.

8. 10 CFR 50, Appendix A, GDC 18.

9. Regulatory Guide 1.108, Rev. 1.

10. Regulatory Guide 1.137, Rev.1.

11. ANSI C84.1-1982.

12. ASME, Boiler and Pressure Vessel Code,Section XI.

13. IEEE Standard 308-1978.

14. Draft Regulatory Guide DG-1021, April 1992.

15. 10 CFR 50.63(a)(3)(ii) as published in Federal Register Vol. 57, No. 77 page 14517, April 21, 1992.

SAN ON0FRE--UNIT 3 3.8-29 Amendment No. 02/28/95

i j

ATTACHMENT "C" PROPOSED SPECIFICATIONS UNIT 2 i

I 1

l

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

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

b. Two diesel generators (DGs) each capable of supplying one train of the onsite Class 1E AC Electrical Power Distribution System.

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

ACTIONS CONDITION REQUIRED ACTION COMPLETION TIME A. One required offsite A.1 Perform SR 3.8.1.1 1 hour1.157407e-5 days <br />2.777778e-4 hours <br />1.653439e-6 weeks <br />3.805e-7 months <br /> circuit inoperable, for required OPERABLE offsite circuit. AND Once per 8 hours9.259259e-5 days <br />0.00222 hours <br />1.322751e-5 weeks <br />3.044e-6 months <br /> thereafter AND A.2 Restore required 72 hours8.333333e-4 days <br />0.02 hours <br />1.190476e-4 weeks <br />2.7396e-5 months <br /> offsite circuit to OPERABLE status. AND 6 10 days from l discovery of failure to meet LC0 (continued)

SAN ONOFRE--UNIT 2 3.8-1 Amendment No.

AC Sources-Operating 3.8.1 ACTIONS (continued)

CONDITION REQUIRED ACTION COMPLETION TIME B. ---------NOTE-------- B.1 Perform SR 3.8.1.1 1 hour1.157407e-5 days <br />2.777778e-4 hours <br />1.653439e-6 weeks <br />3.805e-7 months <br /> On'.a once-per- for the OPERABLE

~ refueling cycle required offsite AND frequency, the~' circuits.

Completion' Time for once per 8 hours9.259259e-5 days <br />0.00222 hours <br />1.322751e-5 weeks <br />3.044e-6 months <br /> Required Action:B.4 thereafter can be extended to;"10 days: AND 10 days from AND discovery of. failure to meet LCO."' B.2 Declare required 4 hours4.62963e-5 days <br />0.00111 hours <br />6.613757e-6 weeks <br />1.522e-6 months <br /> from

---

feature (s) supported discovery of by the inoperable DG Condition B One required DG inoperable when its concurrent with inoperable. redundant required inoperability of features is redundant inoperable. required feature (s)

AND B.3.1 Determine OPERABLE DG 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br /> is not inoperable due to common cause failure.

B.3.2 Perform SR 3.8.1.2 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br /> for OPERABLE DG.

AND B.4 Restore required DG 72 hours8.333333e-4 days <br />0.02 hours <br />1.190476e-4 weeks <br />2.7396e-5 months <br /> 7 days l to OPERABLE status.

AND 6 10 days from l discovery of failure to meet LCO (continued)

J SAN ONOFRE--UNIT 2 3.8-2 Amendment No.

i AC Sources-Operating B 3.8.1 BASES ACTIONS A.2 (continued) systems. In this Condition, however, the remaining OPERABLE offsite circuit and DGs are adequate to supply electrical power to the onsite Class 1E Distribution System.

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

The second Completion Time for Required Action A.2 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 A is entered while, for instance, a DG is inoperable, and that DG is subsequently returned OPERABLE, the LC0 may already have been not met for up to M hews 71 days. This could lead to a total of 111 hours0.00128 days <br />0.0308 hours <br />1.835317e-4 weeks <br />4.22355e-5 months <br /> 10 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 OPERABLE, and an additional 7? hours 71 days (for a total of 917 days) allowed prior to complete restoration of the LCO. The 6 10 day Completion Time provides a limit on the time allowed ~in a specified condition after discovery of failure to meet the LCO. This limit is considered reasonable for situations in which Conditions A and B are entered concurrently. The "ANO" connector between the 72 hour8.333333e-4 days <br />0.02 hours <br />1.190476e-4 weeks <br />2.7396e-5 months <br /> and 6 10 day Completion Time l means that both Completion Times apply simultaneously, and the more restrictive Completion Time must be met.

As in Required Action A.2, the Completion Time allows for an exception to the normal " time zero" for beginning the allowed outage time " clock." This will result in establishing the " time zero" at the time that the LC0 was initially not met, instead of at the time Condition A was entered.

B.1 To ensure a highly reliable power source remains when one of the required DGs is inoperable, it is necessary to verify l

l (continued)

SAN ON0fRE--UNIT 2 3.8-6 Amendment No.

AC Sources-Operating B 3.8.1 BASES l

ACTIONS 8.4 '

(continued) )

According to Regulatory Guide 1.93 (Ref. 5) Reference;16, l )

operation may continue in Condition B for a seriod that' l should not exceed 72 hours8.333333e-4 days <br />0.02 hours <br />1.190476e-4 weeks <br />2.7396e-5 months <br /> 7Edaysk 3 Addition'allyM Reference j 16! states. thatioperationTmayJcontinue. in1 Condition 1 B; for a maximum continuous ' period;off10Ldays-'on: aLonce'-per_-refueling

'~

' ' '~

cycle 1 frequency. l References 16 provides afseriesLof~ deterministic"and probabili sti ce j usti fi cations L for? thel Com'pl etion .T_imes a i corresponding toLthetperiods-in?which continued power

'operatio_nslareiallnwed with Condition:B.

^ ' ~

I In Condition B, the remaining OPERABLE DG and offsite circuits are adequate to supply electrical power to the onsite Class 1E Distribution System. The 72 hour8.333333e-4 days <br />0.02 hours <br />1.190476e-4 weeks <br />2.7396e-5 months <br /> 7fday l Completion Time takes into account the capacity and'

~

capability of the remaining AC sources, a reasonable time for repairs, and the low probability of a DBA occurring ,

during this period. l i

The second Completion Time for Required Action B.4 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, an offsite circuit is inoperable and that circuit is subsequently returned OPERABLE, the LC0 may already have been not met for up to 72 hours8.333333e-4 days <br />0.02 hours <br />1.190476e-4 weeks <br />2.7396e-5 months <br />. This could lead to a total of 111 Scurs 10Tday"s, since initial failure to meet the LCO, l to restore the DG. At this time, an offsite circuit could again become inoperable, the DG restored OPERABLE, and an additional 72 hours8.333333e-4 days <br />0.02 hours <br />1.190476e-4 weeks <br />2.7396e-5 months <br /> (for a total of 913 days) allowed prior to complete restoration of the LCO. Ths 6 10 day Completion Time provides a limit on time allowed in a specified condition after discovery of failure to meet the LCO. This limit is considered reasonable for situations in which  ;

Conditions A and B are entered concurrently. The "AND" '

connector between the 72 hour8.333333e-4 days <br />0.02 hours <br />1.190476e-4 weeks <br />2.7396e-5 months <br /> 7 day and 6 10 day Completion l Times means that both Completion" Times apply simultaneously, and the more restrictive Completion Time must be met. When the:"once-per-refueling (cycle".10-day A0T?is invoked,fthe Completion Time ~ for Required Action- B.4 shall be ".10_ days

~

AND :10idays_- from ~ discovery of failure 'to meet LCO."

(continued)

SAN ON0FRE--UNIT 2 3.8-9 Amendment No.

AC Sources-Operating )

B 3.8.1 BASES ACTIONS B.4 (continued)

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

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

C.1 and C.2 Required Action C.1, which applies when two offsite circuits are inoperable, is intended to provide assurance that an event with a coincident single failure will not result in a complete loss of redundant required safety functions. The Completion Time for this failure of redundant required features is reduced to 12 hours1.388889e-4 days <br />0.00333 hours <br />1.984127e-5 weeks <br />4.566e-6 months <br /> from the 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br /> allowed by Regulatory Guide 1.93 (Ref. 6) for two inoperable required offsite circuits. The 24 hour2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br /> allowance is based upon the assumption that two complete safety trains are OPERABLE.

When a concurrer,t redundant required feature failure exists, this assumption is not the case and a shorter Completion ,

Time of 12 hours1.388889e-4 days <br />0.00333 hours <br />1.984127e-5 weeks <br />4.566e-6 months <br /> is appropriate. These features are powered from redundant AC safety trains. This includes motor driven auxiliary feedwater pumps. Single train turbine driven auxiliary pumps, are not included in the list.

The Completion Time for Required Action C.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 Condition C (two offsite circuits inoperable) and a required feature becomes  !

inoperable, this Completion Time begins to be tracked.

l

)

(continued)

SAN ONOFRE--UNIT 2 3.8-10 Amendment No.

AC Sources-0perating B 3.8.1 BASES j ACTIONS C.1 and C.2 (continued)

According to Regulatory Guide 1.93 (Ref. 6), operation may continue in Condition C for a period that should not exceed 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br />. 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 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 i 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 level of degradation:

a. The configuration of the redundant AC electrical power system that remains available'is not susceptible to a single bus or switching failure; and i

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.

i 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 simultaneous loss of offsite AC sources, a LOCA, and a worst case single failure were l postulated as a part of the design basis in the safety analysis. Thus, the 24 hour2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br /> 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 Reference 6, with the available offsite AC sources two less than required by the LCO, operation may  !

continue for 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br />. If two offsite sources are restored within 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br />, unrestricted operation may continue. If (continued) i SAN ON0FRE--UNIT 2 3.8-11 Amendment No.

l -

t AC Sources-Operating 8 3.8.1 BASES ACTIONS C.1 and C.2 (continued) only one offsite source is restored within 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br />, power operation continues in accordance with condition A.  ;

-D.1 and D.2 Pursuant to LCO 3.0.6, the Distribution System (LC0 3.8.9)

ACTIONS would not be entered even if all AC sources to it were inoperable resulting in de-energization. Therefore, the Required Actions of Condition D are modified by a Note to indicate that when Condition D is entered, the Conditions and Required Actions for LC0 3.8.9, " Distribution Systems-Operating," must be immediately entered. This allows Condition D to provide requirements for the loss of one offsite circuit and one DG without regard to whether a train is de-energized. LC0 3.8.9 provides the appropriate  ;

restrictions for a de-energized train. ,

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

In Condition D, 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 C (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 <br />0.00333 hours <br />1.984127e-5 weeks <br />4.566e-6 months <br /> Completion Time takes into account the capacity and capability of the remaining AC sources, a reasonable time for repairs, and the low probability of a DBA occurring during this period.

E.1 With Train A and Train B DGs inoperable, there are no remaining standby AC sources. Thus, with an assumed loss of offsite electrical power, insufficient standby AC sources j are available to power the minimum required ESF functions.

l l (continued) i SAN ONOFRE--UNIT 2 3.8-12 Amendment No.

AC Sources -Operating B 3.8.1 BASES l

ACTIONS E.1 (continued)

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

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

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

F.1 and F.2 If the inoperable AC electrical power sources cannot be restored to OKRABLE status within the required 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 at least MODE 3 within 6 hours6.944444e-5 days <br />0.00167 hours <br />9.920635e-6 weeks <br />2.283e-6 months <br /> and to MODE 5 within 36 hours4.166667e-4 days <br />0.01 hours <br />5.952381e-5 weeks <br />1.3698e-5 months <br />. The allowed Completion Times are ,

reasonable, based on operating experience, to reach the required unit conditions from full power conditions in an orderly manner and without challenging unit systems.

G.1 Condition G corresponds to a level of degradation in which l 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 operation. The unit is required by LC0 3.0.3 to i commence a controlled shutdown.

l i

i l

(continued) l SAN ONOFRE--UNIT 2 3.8-13 Amendment No.  !

l i

f 1

AC Sources -Operating  !

B 3.8.1 i

BASES l 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, Appendix A, GDC 18 (Ref. 8). Periodic component tests are supplemented by extensive functional tests during refueling outages (under simulated accident conditions).

The SRs for demonstrating the OPERABILITY of the DGs are in accordance with the recommendations of Regulatory Guide 1.9 (Ref. 3), Regulatory Guide 1.108 (Ref. 9), and Regulatory Guide 1.137 (Ref. 10).  ;

Where the SRs discussed herein specify voltage and frequency tolerances, the following is applicable. The minimum steady state output voltage of 3924 V is 90% of the nominal 4360 V output voltage. This value, which is consistent with ANSI C84.1-1982 (Ref. 11), allows for voltage drop to the terminals of 4000 V motors whose minimum operating voltage is specified as 90% or 3600 V. It also allows for voltage ,

drops to motors and other equipment down through the 120 V  !

level where minimum operating voltage is also usually specified as 80% of name plate rating. The specified maximum steady state output voltage of 4796 V allows for the maximum operating voltage specified for 4000 V motors. It ensures that for a lightly loaded distribution system, the voltage at the terminals of 4000 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 values are equal to 2% of the 60 Hz nominal frequency and are derived from the recommendations .

given in Regulatory Guide 1.9 (Ref. 3).

SR 3.8.1.1 This SR assures proper circuit continuity for the offsite AC electrical power supply to the onsite distribution network i and availability of offsite AC electrical power. The breaker alignment verifies that each breaker is in its correct position to ensure that distribution buses and loads are 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.

l (continued)

SAN ONOFRE--UNIT 2 3.8-14 Amendment No.  !

AC Sources-Operating B 3.8.1 l l

i BASES l SURVEILLANCE SR 3.8.1.2 and SR 3.8.1.7

! REQUIREMENTS (continued) These SRs help to ensure the availability of the standby electrical power supply to mitigate DBAs and transients and

! to maintain the unit in a safe shutdown condition. l l

l To minimize the wear on moving parts that do not get ,

I lubricated when the engine is not running, these SRs are )

i modified by a Note (Note 2 for SR 3.8.1.2) to indicate that '

all DG starts for these Surveillances may be preceded by an l engine prelube period and followed by a warmup period prior to loading.

i I

For the purposes of SR 3.8.1.2 and SR 3.8.1.7 testing, the '

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

In order to reduce stress and wear on diesel engines, the DG manufacturer recommends a modified start in which the l starting speed of DGs is limited, warmup is limited to this lower speed, and the DGs are gradually accelerated to synchronous speed prior to loading. This is the intent of l

Note 3.

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 10 secone. The 10 second start requirement supports the asst.:.:ptions of the design basis l LOCA analysis in the UFSAR, Chapter 15 (Ref. 5). l The 10 second start requirement is not applicable to SR 3.8.1.2 (see Note 3) when a modified start procedure as 1 described above is used. l 1

Since SR 3.8.1.7 requires a 10 second start, it is more I l

restrictive than SR 3.8.1.2 and it may be performed in lieu l

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

The normal 31 day Frequency for SR 3.8.1.2 (see l Table 3.8.1-1, " Diesel Generator Test Schedule," in the ,

accompanying LCO) and the 184 day Frequency for SR 3.8.1.7 l are consistent with Regulatory Guide 1.9 (Ref. 3). These l Frequencies provide adequate assurance of DG OPERABILITY, while minimizing degradation resulting from testing.

(continued)

SAN ON0FRE--UNIT 2 3.8-15 Amendment No.

AC Sources-Operating B 3.8.1 l l

BASES t SURVEILLANCE SR 3.8.1.3 REQUIREMENTS (continued) This Surveillance verifies that the DGs are capable of synchronizing with the offsite electrical system and accepting loads greater than or equal to the equivalent of the maximum expected accident loads listed in Reference 2.

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.

Although no power factor requirements are established by this SR, the DG is normally operated at a power factor between 0.8 lagging and 1.0. The 0.8 value is the design rating of the machine, while 1.0 is an operational limitation to ensure circulating currents are minimized.

l The normal 31 day frequency for this Surveillance i (Table 3.8.1-1) is consistent with Regulatory Guide 1.9 (Ref.3).

l This SR is modified by four Notes. Note 1 indicates 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. Note 2 states that momentary transients because of changing bus loads do not invalidate this test.

Similarly, momentary power factor transients above the limit will not invalidate the 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. 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 I the day tank is at or above the level selected to ensure

, adequate fuel oil for a minimum of 1 hour1.157407e-5 days <br />2.777778e-4 hours <br />1.653439e-6 weeks <br />3.805e-7 months <br /> of DG operation at

full load plus 10%. The level is expressed as an equivalent volume in inches. The 30 inch level corresponds to 355.1 i gallons of fuel oil including instrument uncertainties. '

(continued) l l

l SAN ONOFRE--UNIT 2 3.8-16 Amendment No. l

l AC Sources-Operating B 3.8.1 BASES

. SURVEILLANCE SR 3.8.1.4 (continued)

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

SR 3.3.1.5 Microbiological fouling is a major cause of fuel oil j degradation. There are numerous microorganisms 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 microbial survival in the day tanks. This is the most effective means of controlling microbiological fouling. In addition, it eliminates the potential for water entrainment in the fuel oil during DG 1 operation. Water may come from any of several sources, including condensation, ground water, rain water, contaminated fuel oil, and from breakdown of the fuel oil by microorganisms. Frequent checking for and removal 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. 10). This SR is for preventive maintenance. The presence of water does not necessarily represent failure of this SR provided the accumulated water is removed during the performance of this Surveillance.

SR 3.8.1.6 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. This is required to support 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.

(continued)

SAN ONOFRE--UNIT 2 3.8-17 Amendment No.

AC Sources-Operating B 3.8.1 BASES SURVEILLANCE SR 3.8.1.6 (continued)

REQUIREMENTS The design of fuel transfer systems is such that pumps will 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.

SR 3.8.1.7 See SR 3.8.1.2.

SR 3.8.1.8 Transfer of each 4.16 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 power the shutdown loads. The 24 month Frequency of the Surveillance is based on engineering judgment, taking into consideration the unit 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 24 month Frequency.

Therefore, the Frequency was concluded to be acceptable from a reliability standpoint.

This SR is modified by a Note which 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. For this unit, the single load for each DG is the Auxiliary Feedwater pump and its horsepower rating (continued)

SAN ON0FRE--UNIT 2 3.8-18 Amendment No. l

i l AC Sources-Operating l B 3.8.1 BASES )

l SURVEILLANCE SR 3.8.1.9 (continued)

, REQUIREMENTS l is 800 HP. As required by IEEE-308 (Ref. 13), the load

! rejection test is acceptable if the increase in diesel speed does not exceed 75% of the difference between synchronous speed and the overspeed trip setpoint, or 15% above synchronous speed, whichever is lower.

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

. The 4 seconds specified is equal to 80% of a typical l 5 second load sequence interval associated with sequencing .

of the largest load. The voltage and frequency specified i

are consistent with the design range of the equipment l powered by the DG. SR 3.8.1.9.a corresponds to the maximum l l

frequency excursion, while SR 3.8.1.9.b and SR 3.8.1.9.c are l steady state voltage and frequency values to which the i system must recover following load rejection. The 24 month Frequency is consistent with the recommendation of Regulatory Guide 1.9 (Ref 3).

In order to ensure that the DG is tested under load conditions that are as close to design basis conditions as possible, testing is performed using design basis kW loading and maximum kVAR loading permitted during testing. These loadings represent the inductive loading that the DG w.wld experience to the extent practicable and is consister.c with the intent of Regulatory Guide 1.9 (Ref. 3). i This SR is modified by a Note which acknowledges that credit may be taken for unplanned events that satisfy this SR.

SR 3.8.1.10 This Surveillance demonstrates the DG capability to reject a load equal to 94.5% to 100% of its continuous rating 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 i

(continued)

J SAN ON0FRE--UNIT 2 3.8-19 Amendment No.

AC Sources-Operating B 3.8.1 l

BASES SURVEILLANCE SR 3.8.1.10 (continued)

REQUIREMENTS will 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. These loads and limits are consistent with Regulatory Guide 1.9 (Ref. 3). In order to ensure that the DG is tested under load conditions that are as close to design basis conditions as possible, testing is performed using design basis kW loading and maximum kVAR loading permitted during testing. These loadings represent the inductive loading that the DG would experience to the extent practicable and is consistent with the intent of Regulatory Guide 1.9 (Ref. 3).

The ?4 month Frequency is consistent with the recommendation of. Regulatory Guide 1.9 (Ref. 3) and is intended to be consistent with expected fuel cycle lengths.

This SR is modified by a Note which acknowledges that credit may be taken for unplanned events that satisfy this SR.

l l

l SR 3.8.1.11 l As required by Regulatory Guide 1.9 (Ref. 3), this l Surveillance demonstrates the as designed operation of the standby power sources during loss of the offsite source.

This test verifies all actions encountered from the loss of l

offsite power, including shedding of the nonessential loads and energization of the emergency buses and respective loads i

from the DG. It further demonstrates the capability of the l DG to automatically achieve the required voltage and

frequency within the specified time.

l The DG auto-start time of 10 seconds is derived from requirements of the accident analysis to respond to a design basis large break LOCA. The frequency should be restored to within 2% of nominal 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.

(continued)

SAN ON0FRE--UNIT 2 3.8-20 Amendment No.

1

. _ _ . _ _ . _ _ _ _ . ~.___ _.. _ _ _ _._. _ ..___ _ __ _ .-_ _ _ _ .-_ _ _.

l l AC Sources-Operating l j B 3.8.1 1 4

l l

{ BASES l

SURVEILLANCE SR 3.8.1.11 (continued)

REQUIREMENTS

! The requirement to verify the connection and power supply of j permanent loads is intended to satisfactorily show the

relationship of these loads to the DG loading logic. In 1 certain circumstances, many of these loads cannot actually be connected or loaded without undue hardship or potential for undesired operation.

1 For instance, Emergency Core Cooling Systems (ECCS) injection valves are not desired to be stroked open, high j pressure injection systems are not capable of being operated at full flow, or shutdown cooling (SDC) 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 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 24 months is consistent with the recommendations of Regulatory Guide 1.9 (Ref. 3), takes into consideration unit conditions 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 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 continuously circulated and temperature maintained consistent with manufacturer recommendations. Note 2 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 volta within the specified time (10 seconds)ge fromand frequency the design basis actuation signal and operates for 2: 5 minutes. The 5 minute period provides sufficient time to demonstrate stability. l (continued)

SAN ON0FRE--UNIT 2 3.8-21 Amendment No.

AC Sources-0perating B 3.8.1 BASES REFERENCES 5. UFSAR, Chapter 15.

(continued)

6. Regulatory Guide 1.93, Rev. 0.

7. Generic Letter 84-15.

8. 10 CFR 50, Appendix A, GDC 18.

9. Regulatory Guide 1.108, Rev.1.

10. Regulatory Guide 1.137, Rev. 1.

11. ANSI C84,1-1982.

12. ASME, Boiler and Pressure Vessel Code,Section XI.

13. IEEE Standard 308-1978.

14. Draft Regulatory Guide DG-1021, April 1992.

15. 10 CFR 50.63(a)(3)(ii) as published in Federal Register Vol . 57, No. 77 page 14517, April 21,1992.

16h ; ICE NPSDe996X"CEOGlJointJApplicati6ns Reportsfor Emergency [ Diesel 1 Generator.A0TTExtension,";Mayi1995; 1

l l

l

(

i j

l l

1

( SAN ON0FRE--UNIT 2 3.8-29 Amendment No.

I l

! l

ATTACHMENT "D" PROPOSED SPECIFICATIONS UNIT 3

. _ - . . ~ . _ _ . _ . _ _ _ . _ _ _ . _ _ _ _ . _ _ __ _.__ ____ _._ _ _ __ _ _ . _ _ _ _ _ . _ . _ _ _ _ _

l AC Sources-Operating j 3.8.1 j i  !

I i 3.8 ELECTRICAL POWER SYSTEMS.

3.8.1 AC Sources-Operating i

i LC0 3.8.1 The following AC electrical sources shall be OPERABLE:

l l-

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

b. Two diesel generators (DGs) each capable of supplying one train of the onsite Class 1E AC Electrical Power Distribution System.

L I

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

ACTIONS CONDITION REQUIRED ACTION COMPLETION TIME A. One required offsite A.1 Perform SR 3.8.1.1 1 hour1.157407e-5 days <br />2.777778e-4 hours <br />1.653439e-6 weeks <br />3.805e-7 months <br /> circuit inoperable. for required OPERABLE ,

offsite circuit. AND '

Once per 8 hours9.259259e-5 days <br />0.00222 hours <br />1.322751e-5 weeks <br />3.044e-6 months <br /> thereafter AND A.2 Restore required 72 hours8.333333e-4 days <br />0.02 hours <br />1.190476e-4 weeks <br />2.7396e-5 months <br /> offsite circuit to OPERABLE status. AND 6 10 days from l diftuvery of failure to meet LC0 (continued)

SAN ON0FRE--UNIT 3 3.8-1 Amendment No.

AC Sources-Operating 3.8.1 ACTIONS (continued)

CONDITION REQUIRED ACTION COMPLETION TIME B. ---- s--NOTE;-~------ 8.1 Perform SR 3.8.1.1 1 hour1.157407e-5 days <br />2.777778e-4 hours <br />1.653439e-6 weeks <br />3.805e-7 months <br /> On"afonce-pers for the OPERABLE refueling / cycle required offsite AND frequencydthe~ circuits.

Completion] Time lfor Once per 8 hours9.259259e-5 days <br />0.00222 hours <br />1.322751e-5 weeks <br />3.044e-6 months <br /> Required (ActionLB.4 thereafter cantbe extended to?"10 daysf AND':(10; days 4from' AND discovery ofEfailure to meet-LCO."' ~ B.2 Declare required 4 hours4.62963e-5 days <br />0.00111 hours <br />6.613757e-6 weeks <br />1.522e-6 months <br /> from

---

a

~

feature (s) supported discovery of by the inoperable DG Condition B One required DG inoperable when its concurrent with inoperable. redundant required inoperability of features is redundant i noperabl e. required feature (s)

AND B.3.1 Determine OPERABLE DG 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br /> is not inoperable due to common cause failure.

OR B.3.2 Perform SR 3.8.1.2 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br /> for OPERABLE DG.

AND  !

B.4 Restore required DG 72 hours8.333333e-4 days <br />0.02 hours <br />1.190476e-4 weeks <br />2.7396e-5 months <br /> 7 days ^~ l to OPERABLE status. .

AND I 1

6 10 days from l discovery of failure to meet LC0 (continued) l SAN ON0FRE--UNIT 3 3.8-2 Amendment No.

I

AC Sources-0perating B 3.8.1 BASES ACTIONS A.2 (continued) systems. In this Condition, however, the remaining OPERABLE offsite circuit and DGs are adequate to supply electrical power to the onsite Class 1E Distribution System.

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

The second Completion Time for Required Action A.2 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 l the LCO. If Condition A is entered while, for instance, a l DG is inoperable, and that DG is subsequently returned I OPERABLE, the LC0 may already have been not met for up to M hees.7fdays. This could lead to a total of 111 hours0.00128 days <br />0.0308 hours <br />1.835317e-4 weeks <br />4.22355e-5 months <br /> 10 days ~, si'nce~ initial failure to meet the LCO, to restore the offsite circuit. At this time, a DG could again become inoperable, the circuit restored OPERABLE, and an additional 72 hours8.333333e-4 days <br />0.02 hours <br />1.190476e-4 weeks <br />2.7396e-5 months <br /> 7 eda s (for a total of 9 17 days) allowed prior to complete restoration of the LCO. The 6 .10 day Completion Time provides a limit on the time allowed ~in a specified condition after discovery of failure to meet the LCO. This limit is considered reasonable for situations in which Conditions A and B are entered concurrently. The "AND" connector between the 72 hour8.333333e-4 days <br />0.02 hours <br />1.190476e-4 weeks <br />2.7396e-5 months <br /> and 610 day Completion Time means that both Completion Times app 19 simultaneously, and l the more restrictive Completion Time must be met.

As in Required Action A.2, the Completion Time allows for an exception to the normal " time zero" for beginning the allowed outage time " clock." This will result in establishing the " time zero" at the time that the LC0 was initially not met, instead of at the time Condition A was entered.

B.1 To ensure a highly reliable power source remains when one of i the required DGs is inoperable, it is necessary to verify i

(continued) j SAN ON0FRE--UNIT 3 B 3.8-6 Amendment No.

I

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

According to Regulatcry Cuide 1.93 (Ref. 5) ReferenceT16, l operation may continue in Condition B for a pe'Fidd ~thst' should not exceed 72 hour8.333333e-4 days <br />0.02 hours <br />1.190476e-4 weeks <br />2.7396e-5 months <br /> 7Tdays M AdditionallyR Reference 16fstatesjthatioperation?may continue}inicondition!Bifor;:a' maximumfcontinuousLperiod;;of 401 day lsion:-laLonce-per-refueling cicleifrequency; Refe'rencef16 providesiaiseriesiofJdeteministiciand probabilistic; justifications;for theiCompletion? Times corresponding!to thel periods:infwhichicontinuedjpower operationsfare)-lallowedwithcond' tion'B.

In Condition B, the remaining OPERABLE DG and offsite circuits are adequate to supply electrical power to the ,

onsite Class 1E Distribution System. The 72 hour8.333333e-4 days <br />0.02 hours <br />1.190476e-4 weeks <br />2.7396e-5 months <br /> 77 day l Completion Time takes into account the capacity an'd' capability of the remaining AC sources, a reasonable time for repairs, and the low probability of a DBA occurring during this period.

The second Completion Time for Required Action B.4 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 LC0. If Condition B is entered while, for instance, an offsite circuit is inoperable and that circuit is l subsequently returned OPERABLE, the LCO may already have '

been not met for up to 72 hours8.333333e-4 days <br />0.02 hours <br />1.190476e-4 weeks <br />2.7396e-5 months <br />. This could lead to a total of 111 hours0.00128 days <br />0.0308 hours <br />1.835317e-4 weeks <br />4.22355e-5 months <br /> 10' days, since initial failure to meet the LCO, l to restore the DG' ^At this time, an offsite circuit could again become inoperable, the DG restored OPERABLE, and an l additional 72 hours8.333333e-4 days <br />0.02 hours <br />1.190476e-4 weeks <br />2.7396e-5 months <br /> (for a total of 9 13 days) allowed prior  ;

to complete restoration of the LC0. The 6 10 day Completion Time provides a limit on time allowed in a specified condition after discovery of failure to meet the LCO. This limit is considered reasonable for situations in which Conditions A and B are entered concurrently. The "AND" connector between the 72 hour8.333333e-4 days <br />0.02 hours <br />1.190476e-4 weeks <br />2.7396e-5 months <br /> 7fdai and 6 10 day Completion l Times means that both Completion Times apply simultaneously, and the more restrictive Completion Time must be met. fWhen thet"once-per-refuelingEcycle"'10; day?A0TTis invoked; the' l Compl eti on L Ti me}: fo rl Req ui . red L Acti on ? B .4 [ s hal l E be "10 ; days AND 10 days from discovery of? fail.ure toimeet0L.C0;"'

(continued)

SAN ON0FRE--UNIT 3 B 3.8-9 Amendment No. .

1

.~ _

j

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

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

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

C.1 and C.2 Required Action C.1, which applies when two offsite circuits are inoperable, is intended to provide assurance that an event with a coincident single failure will not result in a complete loss of redundant required safety functions. The Completion Time for this failure of redundant required features is reduced to 12 hours1.388889e-4 days <br />0.00333 hours <br />1.984127e-5 weeks <br />4.566e-6 months <br /> from the 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br /> allowed by Regulatory Guide 1.93 (Ref. 6) for two inoperable required offsite circuits. The 24 hour2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br /> allowance is based upon the assumption that two complete suiety trains are OPERABLE.

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

l The Completion Time for Required Action C.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 Condition C (two offsite circuits inoperable) and a required feature becomes inoperable, this Completion Time begins to be tracked.

(continued)

SAN ONOFRE--UNIT 3 B 3.8-10 Amendment No.

AC Sources-0perating B 3.8.1 BASES ACTIONS C.1 and C.2 (continued)

According to Regulatory Guide 1.93 (Ref. 6), operation may continue in Condition C for a period that should not exceed 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br />. 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 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 level of degradation:

a. The configuration of the redundant AC electrical power system that remains available is not susceptible to a single bus or switching failure; and

b. The time required to detect and restore an unavailable 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 simultaneous 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 <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br /> 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 Reference 6, with the available offsite AC sources two less than required by the LC0, operation may continue for 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br />. If two offsite sources are restored within 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br />, unrestricted operation may continue. If (continued)

SAN ON0FRE--UNIT 3 B 3.8-11 Amendment No.

AC Sources-Operating B 3.8.1 BASES ACTIONS C.1 and C.2 (continued) only one offsite source is restored within 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br />, power operation continues in accordance with Condition A.

D.1 and D.2 Pursuant to LC0 3.0.6, the Distribution System (LC0 3.8.9)

ACTIONS would not be entered even if all AC sources to it were inoperable resulting in de-energization. Therefore, the Required Actions of Condition D are modified by a Note to indicate that when Condition D is entered, the Conditions and Required Actions for LC0 3.8.9, " Distribution Systems-0perating," must be immediately entered. This allows Condition D to provide requirements for the loss of one offsite circuit and one DG without regard to whether a train is de-energized. LC0 3.8.9 provides the appropriate restrictions for a de-energized train.

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

In Condition D, 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 C (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 <br />0.00333 hours <br />1.984127e-5 weeks <br />4.566e-6 months <br /> Completion Time takes into account the capacity and capability of the remaining AC sources, a reasonable time for repairs, and the low probability of a DBA occurring during this period.

E.1 With Train A and Train B DGs inoperable, there are no remaining standby AC sources. Thus, with an assumed loss of offsite electrical power, insufficient standby AC sources are available to power the minimum required ESF functions.

(continued)

SAN ON0FRE--UNIT 3 B 3.8-12 Amendment No.

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

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

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

The intent here is to avoid the risk associated with an immediate controlled shutdown and to minimize the risk ,

associated with this level of degradation.

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

F.1 and F.2 If the inoperable AC electrical power sources cannot be restored to OPERABLE status within the required 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 at least MODE 3 within 6 hours6.944444e-5 days <br />0.00167 hours <br />9.920635e-6 weeks <br />2.283e-6 months <br /> and to MODE 5 l within 36 hours4.166667e-4 days <br />0.01 hours <br />5.952381e-5 weeks <br />1.3698e-5 months <br />. The allowed Completion Times are  !

reasonable, based on operating experience, to reach the required unit conditions from full power conditions in an orderly manner and without challenging unit systems.

G.1 Condition G 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 operation. The unit is required by LC0 3.0.3 to commence a controlled shutdown.

(continued)

SAN ON0FRE--UNIT 3 B 3.8-13 Amendment No.

AC Sources-Operating B 3.8.1 BASES 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, Appendix A, GDC 18 (Ref. 8). Periodic component tests are supplemented by extensive functional tests during refueling outages (under simulated accident conditions).

The SRs for demonstrating the OPERABILITY of the DGs are in accordance with the recommendations of Regulatory Guide 1.9 (Ref. 3), Regulatory Guide 1.108 (Ref. 9), and Regulatory Guide 1.137 (Ref. 10).

Where the SRs discussed herein specify voltage and frequency tolerances, the following is applicable. The minimum steady state output voltage of 3924 V is 90% of the nominal 4360 V output voltage. This value, which is consistent with ANSI C84.1-1982 (Ref. 11), allows for voltage drop to the terminals of 4000 V motors whose minimum operating voltage is specified as 90% or 3600 V. It also allows for voltage drops to motors and other equipment down through the 120 V i level where minimum operating voltage is also usually specified as 80% of name plate rating. The specified niaximum steady state output voltage of 4796 V allows for the maximum operating voltage specified for 4000 V motors. It ensures that for a lightly loaded distribution system, the voltage at the terminals of 4000 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 values are equal to 2% of the 60 Hz nominal frequency and are derived from the recommendations given in Regulatory Guide 1.9 (Ref. 3).

SR 3.8.1.1 This SR assures proper circuit continuity for the offsite AC electrical power supply to the onsite distribution network and availability of offsite AC electrical power. The breaker alignment verifies that each breaker is in its correct position to ensure that distribution buses and loads are 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.

(continued)

SAN ON0FRE--UNIT 3 B 3.8-14 Amendment No.

i AC Sources-0perating i B 3.8.1 4

4 BASES l

l SURVEILLANCE SR 3.8.1.2 and SR 3.8.1.7 l

, REQUIREMENTS (continued) These SRs help to ensure the availability of the standby electrical power supply to mitigate DBAs and transients and to 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 are modified by a Note (Note 2 for SR 3.8.1.2) to indicate that all DG starts for these Surveillances may be preceded by an engine prelube period and followed by a warmup period prior to loading.

For the purposes of SR 3.8.1.2 and SR 3.8.1.7 testing, the DGs are started from standby conditions. Standby conditions for a DG mean 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, the DG manufacturer recommends a modified start in which the starting speed of DGs is limited, warmup is limited to this lower speed, and the DGs are gradually accelerated to i synchronous speed prior to loading. This is the intent of Note 3.

SR 3.8.1.7 requires that, at a 184 day Frequency, the DG starts from standby conditions and achieves recuired voltage and frequency within 10 seconds. The 10 seconc start requirement supports the assumptions of the design basis LOCA analysis in the UFSAR, Chapter 15 (Ref. 5).

The 10 second start requirement is not applicable to l SR 3.8.1.2 (see Note 3) when a modified start procedure as described above is used.

Since SR 3.8.1.7 requires a 10 second start, it is more restrictive than SR 3.8.1.2 and it may be performed in lieu of SR 3.8.1.2. This 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," in the accompanying LC0) and the 184 day Frequency for SR 3.8.1.7 are consistent with Regulatory Guide 1.9 (Ref. 3). These Frequencies provide adequate assurance of DG OPERABILITY, while minimizing degradation resulting from testing.

(continued)

SAN ONOFRE--UNIT 3 8 3.8-15 Amendment No.

AC Sources-Operating B 3.8.1 BASES SURVEILLANCE SR 3.8.1.3 REQUIREMENTS (continued) This Surveillance verifies that the DGs are capable of synchronizing with the offsite electrical system and accepting loads greater than or equal to the equivalent of the maximum expected accident loads listed in Reference 2.

A minimum run time of 60 minutes is required to stabilize engine temperatures, while minimizing the time that the DG l is connected to the offsite source.

Although no power factor requirements are established by this SR, the DG is normally operated at a power factor between 0.8 lagging and 1.0. The 0.8 value is the design rating of the machine, while 1.0 is an operational limitation to ensure circulating currents are minimized.

The normal 31 day Frequency for this Surveillance (Table 3.8.1-1) is consistent with Regulatory Guide 1.9 (Ref.3).

This SR is modified by four Notes. Note 1 indicates that diesel en,ine runs for this Surveillance may include gradual loading, as recommended by the manufacturer, so that l mechanical stress and wear on the diesel engine are minimized. Note 2 states that momentary transients because l of changing bus loads do not invalidate this test. '

Similarly, momentary power factor transients above the limit 1 will not invalidate the 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. Note 4 stipulates a l prerequisite requirement for performance of this SR. A )

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

SR 3.8.1.4 This SR provides verification that the leve'l of fuel oil in the day tank is at or above the level selected to ensure adequate fuel oil for a minimum of 1 hour1.157407e-5 days <br />2.777778e-4 hours <br />1.653439e-6 weeks <br />3.805e-7 months <br /> of DG operation at full load plus 10%. The level is expressed as an equivalent volume in inches. The 30 inch level corresponds to 355.1 gallons of fuel oil including instrument uncertainties.

(continued)

SAN ON0FRE--UNIT 3 B 3.8-16 Amendment No.

AC Sources-Operating B 3.8.1 BASES SURVEILLANCE SR 3.8.1.4 (continued)

REQUIREMENTS The 31 day Frequency is adequate to assure that a sufficient supply of fuel oil is available, since low level alarms are provided and unit 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 microorganisms that can grow in fuel oil and cause fouling, but all must have a water environnient in order to survive. Removal of water from the fuel oil day tanks once every 31 days eliminates the necessary environment for microbial survival in the day tanks. This is the most effective means of 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 from breakdown of the fuel oil by microorganisms. Frequent checking for and removal 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. 10). This SR is for preventive maintenance. The presence of water dees not necessarily represent failure of this SR provided 01e accumulated water is removed during the performance of tnis Surveillance.

SR 3.8.1.6 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. This is required to support 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.

(continued)

SAN ON0FRE--UNIT 3 B 3.8-17 Amendment No.

1 1

i AC Sources -Operating B 3.8.1 BASES SURVEILLANCE SR 3.8.1.6 (continued)

REQUIREMENTS The design of fuel transfer systems is such that pumps will 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.

SR 3.8.1.7 See SR 3.8.1.2.

SR 3.8.1.8 Transfer of each 4.16 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 power the shutdown loads. The 24 month Frequency of the Surveillance is based on engineering judgment, taking into consideration the unit 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 24 month Frequency.

Therefore, the Frequency was concluded to be acceptable from a reliability standpoint.

This SR is modified by a Note which 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. For this unit, the single load for each DG is the Auxiliary Feedwater pump and its horsepower rating (continued)

SAN ONUIRE--UNIT 3 B 3.8-18 Amendment No.

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

AC Sources-Operating B 3.8.1

! BASES SURVEILLANCE SR 3.8.1.9 (continued)

REQUIREMENTS is 800 HP. As required by IEEE-308 (Ref. 13), the load rejection test is acceptable if the increase in diesel speed does not exceed 75% of the difference between synchronous speed and the overspeed trip setpoint, or 15% above synchronous speed, whichever is lower.

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

The 4 seconds specified is equal to 80% of a typical 5 second load sequence interval associated with sequencing of the 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 24 month Frequency is consistent with the recommendation of Regulatory Guide 1.9 (Ref. 3) .

In order to ensure that the DG is tested under load conditions that are as close to design basis conditions as possible, testing is performed using design basis kW loading and maximum kVAR loading permitted during testing. These loadings represent the inductive loading that the DG would experience to the extent practicable and is consistent with the intent of Regulatory Guide 1.9 (Ref. 3).

This SR is modified by a Note which acknowledges that credit may be taken for unplanned events that satisfy this SR.

SR 3.8.1.10 This Surveillance demonstrates the DG capability to reject a load equal to 94.5% to 100% of its continuous rating 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 i 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 i (continued)

SAN ON0FRE--UNIT 3 B 3.8-19 Amendment No.

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

AC Sources-Operating

, B 3.8.1 l

a BASES SURVEILLANCE SR 3.8.1.10 (continued)

REQUIREMENTS will 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. These loads and limits are consistent with Regulatory Guide 1.9 (Ref. 3). In order to ensure that the DG is tested under load conditions that are 1 as close to design basis conditions as possible, testing is  ;

performed using design basis kW loading and maximum kVAR loading permitted during testing. These loadings represent the inductive loading that the DG would experience to the extent practicable and is consistent with the intent of Regulatory Guide 1.9 (Ref. 3) .

The 24 month Frequency is consistent with the recommendation of Regulatory Guide 1.9 (Ref. 3) and is intended to be consistent with expected fuel cycle lengths.

This SR is modified by a Note which acknowledges that credit may be taken for unplanned events that satisfy this SR.

SR 3.8.1.11 l As required by Regulatory Guide 1.9 (Ref. 3), this Surveillance demonstrates the as designed operation of the standby power sources during loss of the offsite source.

This test verifies all actions encountered from the loss of offsite power, including shedding of the nonessential loads and energization of the emergency buses and respective loads from the DG. It further demonstrates the capability of the l DG to automatically achieve the required voltage and frequency within the specified time.

The DG auto-start time of 10 seconds is derived from requirements of the accident analysis to respond to a design basis large break LOCA. The frequency should be restored to within 2% of nominal 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.

(continued)

SAN ON0FRE--UNIT 3 8 3.8-20 Amendment No.

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

REQUIREMENTS The requirement to verify the connection and power supply of permanent loads is intended to satisfactorily show the l relationship of these loads to the 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, Emergency Core Cooling Systems (ECCS) injection valves are not desired to be stroked open, high pressure injection systems are not capable of being operated at full flow, or shutdown cooling (SDC) 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 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 24 months is consistent with the recommendations of Regulatory Guide 1.9 (Ref. 3), takes into consideration unit conditions 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 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 continuously circulated and temperature maintained consistent with manufacturer recommendations. Note 2 acknowledges that credit may be taken for unplanned events .

that satisfy this SR. l SR 3.8.1.12 i This Surveillance demonstrates that the DG automatically l starts and achieves the re uired voltage and frequency within the specified time 10 seconds) from the design basis )

actuation signal and operates for 2: 5 minutes. The 5 minute period provides sufficient time to demonstrate stability.

(continued)

SAN ON0FRE--UNIT 3 B 3.8-21 Amendment No.

)

AC Sources-0perating B 3.8.1 BASES REFERENCES 5. UFSAR, Chapter 15.

(continued)

6. Regulatory Guide 1.93, Rev. O. ,

7. Generic Letter 84-15.

8. 10 CFR 50, Appendix A, GDC 18.

9. Regulatory Guide 1.108, Rev.1.

10. Regulatory Guide 1.137, Rev. 1.

11. ANSI C84.1-1982.

12. ASME, Boiler and Pressure Vessel Code,Section XI.

13. IEEE Standard 308-1978.

14. Draft Regulatory Guide DG-1021, April 1992.

15. 10 CFR 50.63(a)(3)(ii) as published in Federal Register Vol. 57, No. 77 page 14517, April 21, 1992.

16. ICE.1:NPSD 996M"CEOG9oi_ntlApplicat_i~onsf. Report:ifor Emergency!DieselsGenerator::: A0Tf Extension,"TMayL1995!

i l

1 i

i l

l l

SAN ONOFRE--UNIT 3 B 3.8-29 Amendment No.

1

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