Text

Proposed Tech Specs Revising Single Largest Load Reject Value for Div III Diesel Generator & Clarifying Requirements for Automatic Bypassing of Diesel Generator Trips on ECCS Actuation Signal
	ML20043B176
Person / Time
Site:	LaSalle
Issue date:	05/16/1990
From:	; COMMONWEALTH EDISON CO.
To:	;
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ML20043B175	List: ML20043B174; ML20043B176;
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	Download: ML20043B176 (24)
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ATTACIBIENT B PROPOSED CHANGES TO THE TECHNICAL i SPRIHCATIWS_ZDILORElWitING . LICIIMS5 l..

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, . ELECTRICAL POWER SYSTEMS SURVEILLANCE REQUIREMENTS j

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6. Verifying the diesel generator is aligned to provide standby i power to the associated emergency busses.

7. Verifying the pressure.in all diesel generator air start receivers to be greater than or equal to 200 psig,

b. At least once per 31 days and after each operation of the diesel where the period of operation was greater than or equal to 1 hour1.157407e-5 days 2.777778e-4 hours 1.653439e-6 weeks 3.805e-7 months by i checking for and removing accumulated water from the day fuel tanks.

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c. At least once per 92 days and from new fuel oil prior to addition to the storage tanks by verifying that a sample obtained in accordance with ASTM-0270-1975 has a water and sediment content of less than or equal to u.05 volume percent and a kinematic viscosity @ 40'C of '

greater than or equal to 1.9 but less than or equal to 4.1 when '

tested in accordance with ASTM-0975-77, and an impurity level.of less than 2 mg of insolubles per 100 ml when tested in accordance !

with ASTM-D2274-70.

d. At least once per 18 months during shutdown by: l Subjecting the diesel to an inspection in accordance with-

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procedures prepared in conjunction with its manufacturer's recommendations for this class of rtandby service.

2. Verifying the diesel generator capability

to reject a load of creater than or egal to 1190 kW for diesel generator 0, greater ,

than or equsi to 636 kW for diosel generators 1A and 2A, and -

greater than or equal to tjHM kW for diesel generator 1B while p otainihg engine speed less than or equal to 75% of the d2f$2l difference between nominal speed and the overspeed trip setpoint or 15% above nominal, whichever is less.

3. Verifying the diesel generator capability

to reject a load of 2600 kW without tripping. The generator voltage shall not ;

exce.ed 5000 volts during and following the load rejection.

4. Simulating a loss of offsite power

by itself, and:

a) For Divisions 1 and 2 and for Unit 2 Division 2: l

1) Verifying de-energization of the emergency busses and-load shedding from the emergency busses. ;

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All planned d esel generator starts performed for the purpose of meeting

.these surveillance requirements may be preceded by an engine prelube period, as recommended by the manufacturer. l LASALLE-UNIT 1 3/4 8-4 Amendment No. 72 i

.- ELECTRICAL POWER SYSTEMS SURVEILLANCE REQUIREMENTS (Continued) ,

2) Verifying the diesel generator starts on the auto-start, sigaal, energizes the emergency busses with permanently connected loads within 13 seconds, energizes the auto-connected emergency loads through the load 1 sequencer and operates for greater than or equal to 5 minutes while its generator is. loaded with the emergency loads. After energization, the steady state voltage and frequency of the emergency busses shall be maintained at 4160 1416 volts and 60 11.2 Hz during this test.

b) For Division 3:

1) . Verifying de-energization of-the emergency bus. ;

2) Verifying the diesel generator starts on the. auto-start signal,. energizes the emergency bus with its loads within 13 seconds and operates for greater than or ,

equal to 5 minutes while its generator is loaded with the emergency loads. After energization, the steady state voltage and frequency of the emergency bus shall be maintained at 4160 1416 volts and 60 11.2 Hz during this test.

7. Vorifying that all diesel generator 0, 1A, and 18 automatic trips '

except the following are automatically. bypassed on an ECCS :

' actuation signal: ;

a) For Divisions 1 and 2 - engine overspeed, generator t differential current, and emergency manual stop.

b) Fo vision 3 - engine overspeed, generator differential or ove urrent, and emergency manual stop.

8. Verifying the diesel generator operates

for at least 24 hours2.777778e-4 days 0.00667 hours 3.968254e-5 weeks 9.132e-6 months .

During the first 2 hours2.314815e-5 days 5.555556e-4 hours 3.306878e-6 weeks 7.61e-7 months of this test, the diesel generator shall be loaded to greater than or equal to 2860 kW and during the remaining 22 hours2.546296e-4 days 0.00611 hours 3.637566e-5 weeks 8.371e-6 months of this test, the diesel generator shall t be loaded to 2400 kW to 2600 kW.*** The generator voltage and frequency shall be 4160 +420, -150 volts and 60 +3.0, -1.2 Hz within 13 seconds after the start signal; the steady state i

All planned diesel generator starts performed for the purpose of meeting

-these surveillance requirements may be preceded by an engine prelube period,

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as. recommended by the manufacturer.

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- - Transients, outside of this load band, do not invalidate the surveillance l tests.

L LASALLE-UNIT 1 3/4 8-6 Amendment No. 72 J

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E y ELECTRICAL POWER SYSTEMS

! SURVEILLANCE REQUIREMENTS ,

[ 6. Verifying the diesel generator.is aligned to provide standby power to the associated emergency busses. ,

7. Verifying the pressure in all diesel generator air start receivers to be greater than or equal to 200 psig.

b. At least once per 31 days and after each operation of the diesel L where the period of operas.isn was greater than or equal to 1 hour1.157407e-5 days 2.777778e-4 hours 1.653439e-6 weeks 3.805e-7 months by checking for and removing accumulated water from the day fuel tanks. :

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, c. At least once per 92 days and from new fuel oil prior to addition to -

the storage tanks by verifying that a sample obtained in accordance with ASTM-D270-1975 has a water and sediment content of less than or equal to 0.05 volume percent and a kinematic viscosity @ 40 C of greater than or equal to 1.9 but less than or equal to 4.1 when tested in accordance with ASTM-D975-77, and an impurity level of less than 2 mg of insolubles per 100'ml when tested in accordance with ASTM-D2274-70.

d. At least once per 18 months during shutdown by:

1. Subjecting the diesel to an inspe: tion in accordance with procedures prepared in conjunction with its manufacturer's recommendations for this class of standby service. ;

2. Verifying the diesel generator capability

to reject a load of greater than or equal to 1190 LW for diesel generator 0, greater than or equal to 638 kW for diesel generators 1A and 2A, and greater than or equal to @ M kW for diesel generator 2B while M2,l 1I maintaining engine speed Tess than or equal to 75% of the

i. difference between nominal speed and the overspeed trip setpoint ,

ll or 15% above nominal, whichever -is -less.

3. Verifying the diesel generator capability

to reject a load of 2600 kW without tripping. The generator voltage shall not

-exceed 5000 volts during and following the load rejection. ;

4. Simulating a loss of offsite power

by itself, and:

a) For Divisions 1 and 2 and for Unit 1 Division 2:

1) Verifying de-energization of the emergency busses and load shedding from the emergency busses.

All planned diesel generator starts performed for the purpose of meeting these surveillance requirements may be preceded by an engine prelube period, as recommended by the manufacturer. ,

LASALLE - UNIT 2 3/4 8-4 Amendment No. 56

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'm EtECTRICAL p0WER SYSTEMS i SURVEILLANCE REQUIREMENTS (Continued)

2) Verifying the diesel generator starts on the auto-start a signal, energizes the emergency busses with permanently connected loads within 13 seconds, energizes the auto-connected emergency loads through the lead r; sequencer and operates for greater than or equal to 5 minutes while its generator is loaded with the emergency loads. After energization, the steady a state voltage and frequency of the emergency busses b shall be maintained at 4160 1416 volts and 60 11.2 Hz during this test.

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i b) For Division 3:

1) Verifying de-energization of the emergency bus.

2) Verifying the diesel generator starts on the autn-start signal, energizes the emergency bus with its loads within 13 seconds and operates for greater than or .

equal to 5 minutes while its generator is loaded with the emergency loads. After energization, the steady state voltage and frequency of the emergency bus shall be maintained at 4160 1416 volts'and 60 11.2 Hz during this test.

7. Verifyino that all diesel generator 0, 2A, and 2B automatic trips except the following are automatically bypassed on an ECCS actuation signal:

a)- For Divisions 1 and 2 - engine overspeed, generator differential current, end emergency nanual stop, b For Division 3 - engine overspeed, generator differential r ove urrent, and emergency manual stop,

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8. Verifying the diesel generator operates

for at least'24 hours2.777778e-4 days 0.00667 hours 3.968254e-5 weeks 9.132e-6 months .

During the first 2 hours2.314815e-5 days 5.555556e-4 hours 3.306878e-6 weeks 7.61e-7 months of this test, the diesel generator shall be loaded to greater than or equal to 2860 kW and during the remaining 22 hours2.546296e-4 days 0.00611 hours 3.637566e-5 weeks 8.371e-6 months of this test, the diesel generator shall be loaded to 2400 kW to 2600 kW.*** The generator voltage and frequency shall be 4160 +420, -150 volts and 60 +3.0, -1.2 Hz within 13 seconds after the start signal; the steady-state

All planned diesel generator starts performed for the purpose of meeting these surveillance requirements may be preceded by an engine prelube period, as recommended by the manufacturer.

- - Transients, outside of this load band, do not invalidate the surveillance

. tests.

LASALLE - UNIT 2 3/4 8-6 Amendment No. 56

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.-- AIIACIMENLC

? ElGNIEICMiLilAZAlWLC.ONSIDUAILON I Commonwealth Edison has evaluated the proposed Technical Specification ;

Amendment and detemined that it does not represent a significant hazards ,

consideration. Itas2d on the criteria for defining a significant harards consideration established in 100FR$0.92, operation of 1.aSalle County Station Units 1 and 2 in accordance with the proposed amendment will_ncil

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1) Involve a significant increase in the probability or consequences of an accident previously evaluated because }

The llPCS system automatically initiates on a low reactor water level on a high drywell pressure signal. The system in designed to provide the !

!' necessary cooling for the reactor core to prevent fuel cladding damage following any break in the nuclear system piping over a wide range of

-pressures. For small breaks that do not result in rapid reactor depressurization, the system maintains reactor water level and

, depressurizes the vessel. For large breaks the llPCS system cools the core by a spray. The HPCS system also serves as a backup to the reactor core isolation cooling system during reactor isolation events. If the normal power source (system auxiliary transformer) for the HPCS system ,

is lost the Division 3 diesel generator provides an titernate source of power.

The proposed amendment increases the Unit 1 and 2 technical specification surveillance " single large load reject" test value for the ESF Division 3 diesel generators (Technical Specification 4.8.1.1.2.d.2) .

to the more conservative value specifled in the UFSAR (Table 8.3-1).

This enhancement to the test program will help to assure the reliability and availability to the ESF Division 3 diesel generators under all operating conditions. This enhancement will be accomplished by ensuring that the technical specification load reject test value is equal to or greater than the maximum load requirement for the !!PCS pump which is the single largest Division 3 load. Additionally, this proposed amendment merely clarifies the intent of the technical specification requirements and does not involve any changes to the operation of the facility as described in the UFSAR.

2) Create the possibility of a new or different kind of accident from any accident previously evaluated because This proposal does not involve any modifications to the facility or ,.

changes to the operation of the facility as described in the UFSAR, therefore it cannot create the possibility of a new or different kind of eccident.

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3) Involve a significant reduction in the margin of safety because The proposed amendment raises the Division 3 test load requirement for loitiation of the " single large load reject" surveillance test to the more conservative UFSAR value. The proposal does not alter the technical specification acceptance criteria for the test which specifien the amount that the diesel generatort are allowed to overspeed following the initiation of the test. Additionally this proposed amendment is an administrative change which does not modify the intent of the technical specifications, therefore, the margin of safety is not decreased and may actually be increased slightly.

Guidance has been provided in " Final procedures and Stemdards on No Significant Hazards Considerations," Final Fule, 51 FR 7744, for the application of standards to license change requests for determination of the existence of significant hazards considerations. This document provides examples of amendment which are and are not considered likely to involve significant hazards considerations. This proposed amendment most closely resembles example 1.C.2.e.ii, of the examples of amendments which do not involve a significant hazard consideration, "a change that constitutes an additional limitation, restriction or control not prer.ently in the technical specifications, e.g., a more stringent requirement." This proposed amendment does nqt involve a significant relaxation of the criteria used to establish sefety limits, a significant relaxation of the bases for the ,

limiting safety system settings or a o36nificant relaxation of the banes for l the limiting coaditions for operations. Therefore, based on the guidance provided in the Federal Register and tue criteria established in 10CFR50.92(e), the proposed change doeo not constitute a significant hazards conalderation.

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F ATIACMENT_R REFERElfCES

' a. Inspection Report $0-373/89018, 50-374/89018, dated November 27, 1989. r i

b. T.J. Kovach letter to A. Bert Davis, dated January 22, 1990 LaSalle .

! County Station Units 1 and 2 Response to Inspection Report Nos. I 50-373/89018 and 50-374/89018 Special Maintenance Team Inspection. !

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c. UFSAR Section 6.3.2.2.1, Iligh Pressure Core Spray System.

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d. UFSAR Section 8.1.2, Onsite Power Systems - Summary Description.

e. UFSAR Section 8.3.1.1.2, Unit Class 1E A-C Power Systems.

f. UFSAR Figure 6.3-3, Revision 5, April 1989, HPCS Pump Characteristics. ;

g. Selection, Design, and Qualification of Diesel-Generator Units Used as ,

Standby (Onsite) Electrical Power Systems at Nuclear Power Plants, Regulatory Guide 1.9, Revision 2, December 1979. :

h. Safety Evaluation Report Related to the Operation of LaSelle County Station Units 1 and 2, NUdhG 0519 March 1981.

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i. Diesel Generator Protective Trip Circuit Bypasses, Branch Technical '

Yonition ICSB 1) (PSB), Revision 1. '

j. Diesel Generator Protective Trip Circuit Bypasses, Branch Technical Position ICSE 17 (PSB), Revision 2, July 1981. :

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/099179

.- . REFEREN CE. A l

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.. I from the day tank which led to an incorrect conclusion that the required amount of fuel was present. In fact, the amount of fuel j available would be insufficient to meet the UFSAR commitment with '

the current alarm setting, j i

The lice'nsee was made aware of this situation and had initiated i corrective action while the team was still on site to revise the i alarm setpoint. However, the occurrence of this error points to ;

a fault in the licensee's program for performance and review of design calculations. {

F The failure to detect errors in the calculation to support the current alarm setpoint indicated a weakness in the performance -l of calculational reviews and verifications that are prescribed '

in ANSI /ASME Paragraph 4.1.1.4 NQA-1-1983.

below. This weakness is further discussed in :

, 4.1.1.3 HPCS Diesel Generator load Rejection Tests j The team determined that the TS Sections 4.8.1.1.2.d.2 & 3 identified values for performing the full load rejection test and single largest t load rejection test that were less than the values given in UFSAR Table 8.3.1. Table 8.3.1 of the UFSAR identified the single largest '7 load on the HPCS diesel as 3050 bhp which equates to 2528 kw and gave the total load as 3280 bhp which equates to 2719 kw. These loads were at variance with the TS which identified 2381 kw for the large ;

load rejection test and 2600 kw for the full load rejection test.

The intent of these TS surveillances was to ensure that the diesel 'l generator would not trip off if the bus it was powering was lost and i to ensure that the diesel generator wuld continue to supply power to the bus with no more than a 75% drop in voltage if the largest i load on the bus were to trip off. This position is consistent with '

that presented in Regul.atory Guide 1.9, " Selection, Design, and Qualification of Diesel-Generator' Units Used as Standby (Onsite)

Electric Power Systees at Nuclear Power Plants," Revision 2.

L The team agreed that the single largest load contained in Table 8.3.1 i used a conservative pump efficiency of 90% in arriving at the 2528 kw; '!

however, the manufacturer's certified pump curve gave a load of 2408 kw l at 3030 bhp.. The 2381 kw load specified in TS appeared to come from i data obtained during a prototype test performed at LaSalle by General Electric. The team considered that the conditions under which that arototype test was performed did not represent the design or normal ;

operational conditions of the plant, for example, the strainer was ,

not 50% plugged per the design requirement and water temperature of :

tha suppression pool was lower than seen during normal operations, t It appeared that a non-conservative value was used for the TS -

surveillance. '

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The licensee stated that the requirement for the full load reject test was the continuous rating of the diesel generator, which is 2600 kw. However, the licensee had utilized the 2000 hour0.0231 days 0.556 hours 0.00331 weeks 7.61e-4 months rating in the actual sizihg of the diesel.

The licensee committed to revise the TS to incorporate the appropriate values for " full load" and " single largest load" that met the intent of the surveillance requirement. This will be tracked as an Open Item (373/89018-02;374/89018-02).

4.1.1.4 Design Calculations During the review of the design bases for HPCS, the team found many examples where calculations were inconsistent, utilized different assumptions for the same variable, were incomplete, or were missing. With few exceptions, these calculations had been performed as part of the original station design in 1973. Some examples included the following:

i Calculation entitled "Hpts Pump Discharge Pressure - Design" used a maximum suction pressure of 30 psig from the cycled condensate storage tank and 56 psig from the suppression pool, while calculation entitled "HPCS Design Pressure & Temperature" identified the suction line pressure as 100 psig.

Calculation "HPCS Design Pressure & Temperature" was missing L

the design temperature and pressure for the discharge of the water leg pump, even though the need for this information was noted in the calculation.

Calculathn entitled "HPCS Safety /Reitsf Valve Sizing" i identiffed pressure operating the set point for valve is 1225 psig. E22-F035 as H 00 Asipand

The 2100 psig snmW wa,e

' been 1100 psid, and the opercting pressure : lid wt agree with calculation "HPCS Operating Conditions." Fu-thee, the por tion of the calculation dealing with valve Ef.2-F036 had been l

i supersected by calculation HP-11. " Resetting Valve E22-F033",

i which was not noted in eithsr calculation. The new calculation useo a meximum shuteff Foad and wetion head whir.h differed from those in the "HOCS rump Discharge Pressure - Design" calculation.

Calculation DO-7, " Diesel Oil Storage Capacity," concluded that the HPCS diesel generator fuel oil storage tank capacity wn Insufficient to meet the seven day fuel storage requirement.

Although, the tank was subsequently modified, there was no calculation confirming the adequacy of the modified tank. A preliminary, unreviewed and unapproved calculation, DO-11

" Diesel Oil Storage and Day Tank Usable Capacity - HPCS Diesel "

dated 8/7/89 was prepared during this inspection which indicated that sufficient fuel oil storage capacity was available.

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- Ef.FERENCf. E LSCS-UFSAR

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TABLE 8.3-1 REV. 6 - APRIL 1990 l

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TABLE 8.3-1 (SHEET 3 OF 3)

- Assumptions:

A. Total loss of plant notscal ac aGuillary power B. Unit 1 in LOCA conditi9n-C. Unit 2 in hot shutdown condition D. Five diesel-generator sets 6 tart E. Intermittent loads expected to operv e for very short periods of time, such as motor-operated valves and sump pumps, are i.ot included in the tabulation since inherent conservatism loads.

already containcd in the tabulated values mre than accounts for these Notes:

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$ Delay times may exceed those indicated by 2 seconds

" 2 t'2 3

Loads have access to ESF buses (manual) c

." Electric motor driven enly n 9

' y Computer power supplies can be pewared from either unit

5 Delay time is dependent on syst.em ccaponent operating times O

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LA SALLE COUNTY STATION LOCA 1 F S UPDATED FINA'L SAFETY ANALYSIS REPORT GESTR Infor:::ation, see '

Reference 8. FIGURE 6.3-3

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1 L' HPCS PUMP CHARACTERISTICS REV. 5 - APRIL 1989

- CDE..otdH G3D1 CD, C.R Barserwcc & ,,,i,1,, , ,

"a u.s. NUCLEAR RESULATORY CONINDEi.sg o, osse,,,ber im l y, t rI\... REGULATORY GUIDE

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" n m u SELECTION, DE800N, AND QUALIFICATION OF DIESEL GENERATOR UNITS USED

. ej STANDBY (ONSITE) ELECTRIC POWER SYSTEIN AT NUCLEAR PO ogadpment needed to snaistain the plant in a esfe ocedition A. INTRODUCTION if as estended los of offsith power oceers.

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General Design Critados 17 " Electric Power Systems," I88E 884 3871977,"lEBE Standard Criterie for Dieseh of Appendia A. " General Design Cr6tada for Nuclear Power . Geeseener Unite Applied as Standby Power Supplies for No- .

Plants," to 10CFR Part 50," Domestic ussestas of Prodes. cheer Power Generaties Stations,"' delinestes principal tion and UtGination Focaities," includes a requirement that desige esitoria and geslineation testing requirements that,if the emelte einotric power system hees mafGeiset espaatty fotomed, wW help eneuse that selected diesehsenerator l and' capability to eneum that (1) specified acceptable fuel units seest their performance end niiabuity mquirements, design hmits and deegn conditions of the seactor coolant IEEE Std 3871977 was developed by Working Group 4.2C pressure boundary are not eaceeded as a result of anticipated of the Nuelser Power Engineersas Committee (NPEC) of operational occurrences and (2) the core is cooled and coe- the lentitute of Electrieel and Electron 6cs Engineers, Inc.

tainment integrity and other vital functions are maintained (IEEE), approwd by NPEC, and subsequently approwd by in the event of postulated socidents. the IEEE Standards Board on September 9,1976. IEEE Std 387 1977 is mapplementary to IEEE Std 3081974,"fEEE Criteriom ill, " Design Control," of Appendix 3," Quality Standard Qiteria for Ones IE Power Systems and Nuclear Assurance Criteria for, Nuclear Power Plants and Fuel Power Genersting Stations,"3 and specifically amplifies j

' Reprocessing Plants," to 10 CFR Part 50 includes a requin- l passeraph 5.2.4, " Standby Power Supplies," of that docu.

ment that measures be provided for verifying or checking meat with respect to the application of dieselgenerator the adequacy of design by design reviews, by the use of un6ts. IEEE S'd 308 1974 is endorsed, with certain excep-

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y alternative or simpElied calcuktional methods, or by the tions, by Regunstory Guide 1.32," Criteria f or Safety Italated I

' performance of a mitable testing program. E%ctric Power Systess fot Wuc1wr Prver Plar ts."

Diessi-senerater urits have beca widely taed as tha A knowledge of se charsentrisths of each load is ;

power source for the onsite citetric power systema. This essential in embbshing the bases for the seicetion of a l

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regulatory guide descntcs a method acceptable to the NRC dieselgenerstor unit that is able to accept large trads in l L staff for comply!ng wit'i the Commission's require:nente i repid succession. The majority of the emergency loads are l that diesel generstM units intended for usr as onsite power large ir:daction motors. This type of rnotor draws, at ful!

l souten in nucle.ar power 14r.nts be pelected with sufficient L vostage, a starting current five t e eight times its reted toed t I

capacity and 5c qualified for this service. The Adytsary current.- The sudden lasgs iT crear,es in curnnt drawtr frarp CemNttee on Reactor Safertards has been wiralted the diesel generator rese!hr4 from we stn4 tup of inductbn l conw. ting trots guide ud has ccawr,*d in tne regulktory motors sca result in substuthi vchase reductiour. The poeidos, lower voltage could prevent a motor from starting, i.e.,

accelerating its load to rated speed in the required thie, or B. DitCUS$40N cause a running motor to coast down or stall. Other loads might be lost if their contactors drop out. Recovery frora A dieselgeestater unit eslooted for mes la en onsite the tremeleet caused by starting large motors or from the electric power system thould have the espebGity to (l) start loss of a large load could cause diesel engine overspeed and nooslorate a number of lares motor loads in rapid which, if esosenve, might result in a trip of the engine, succeselon and be able to sustain the loss of allor any part of such loads and maintain voltage sad fsequency withis -

acceptable limits and (2) empply power continuously to the , C.pl.s r t obt.4med froen th. la.e.etet, or D etr6 cal a.n.d Un e .rs, lac., Yo,it.d Easta. rtas C.ns r Hs E t 47ts SW.t.sD Ywen rk, Peew

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system should be'selseted C3 hees e continuous lood reting I

Y. Thee's same sensequenses een aise moult from the eup b densed ,6 Session 3.7.8 of ISSE Std 3871977) equel leefoe e#est of e esquence of more moderets tsessionu if

. to or poster then the som af the senestvetively estimated the eraten le set paradened to resseer suffielently botween ' leado needed to be powered by that unit et say one time. [

seassesfes steps in a needles gegeease, is the ebesses of fety subetontieted perfernense ehereewr. \

tedes for meshenimi equipment such as pumps, the shest:6s Oeneregy a tes tes indestry penedse to speelfy a meter drin reelage should be seleuteted udas senservettee monimum estenge sedesses of 10 to 18 percent whos estianstee of these ehessetestedse, e.g., pump rument send 6-eteriins lasse messes tem leegnespeefty power systems and tiens and meter afholensten of 90 pereent er less and a voltage redesties of to to 30 percent whom starting these motose from liedeed seposity power eeurese such as diesel- power fasesse of Sipenest erlem.

generater untee. Laags industica metere een asideve rated 2. At the spesellesliesses stage of review, the predicted speed la less thes $ esseeds whee powered from odoquetely needs should not enseed the ehert time reting (as defined in sised diesel esasesser unos that are espsble of restering the Section 3.7.2 ef IEEE Std 3871977) of the dieselgenerster voltage to 90 pereset of nominalin about I second.

undt.

protection of the dieselgemeester unit from esseedvs 3. In Seetles 3.1.1,'Seneral,"of 1885 Sed 3871977 everspeed, which een result from a less oflead,le afforded ;

requirements of IEEE Std 306 lp?d should be used subioet -

by the immedines opersties of a dieselgenerator unit trip, to the regulatory position of Reguistory Guide 1.32.

usually at at iI$ percent of nominal speed. As addition, tho' generetor differostial trip must operate immediately la 4. Section 3.1.2, 'Mosbaaloal and Electrieal Capabilities,"

order to provost substantial damese to the genermtor. There of IEEE Std 3871977 portaine, la part, to the starting and are other protective tripe provided to protect the diesel-lood easeptias espebilities of the M'.;ntor unit. In l generator units froen possible damage or degredation, conduastice with Section 5.1.2, each dieselgenerator unit l However, these tripe sould laterfere with the suossesful thould be espeble of starting and seselerating to rated l functionias of the unit when it le snoet needed,1.e., during speed, in the required sequeses, all the needed emaineered eccident conditions. Experience hee shown that there have safety feature and emergency shutdown loads. The diesel-been numerous oncesions wbes these trips have needlessly generator unit deales should be such that at no time during shut down dieselgenerator unite because of spurious the loaalas esquence should the frequency and voltage i operation of a trip cir'cuit. Ccnerquently, it le important decreens to less then 95 pereest of nominal and 75 percent I

that measures be taken to et.eure that spurious actuation of of nominal, .wr,. (A larger decrease in voltage and these other protactlive tripe does not prevent the diesel-freque20y may be justified for e dieselgenerator unit that gener. tot unit from perfeeming its function, carrios paly one large connected load.) Frequency should (

l '

i te astored to withbe 2 percent of nominal, and volttee l Ths unter*sinties inbtrent in estimates of safst/ loeds rt should be restozed to within 10 percent of nominal withm tbr constructiort permit stay of design are sometmes of such 60 percent of each loadsequence tirm intervd (A grestu l ,

msgr.itude that it is pNdent to provide a substant.a! narda in'selectirit the load capabl'ities of tne d;esel serierator unit, percenttte el the tune interal uy be tisets if l' can to ? ,

justilled by analysis. Ilowev*r, the leAseqwne umt l This margh c.an be providec by estimating the loads censn-interval should iticludt sufficient snargin M eNount fri ite vaively 6n3 s;lgting the continuous rating of ina. diesek accuracy sm' repeatability of the load-sautoce uron] , '

ser.ersar u% to that it exceeds the sum of the loads r:eeded Durirsmover/ irom transients ccuted by tiepbad is.rtet. sea r IL at any or.e tima. A more accurate e9f.unate of salsty lo&ds is or resu!tng fiorn the disconnet. tion of the larsest :erje .

{ 1 pos2Mo dwins the oWinting license stage of rMse l'eown de'Aiaed designs have %cn tonpleted and hrwearbor.a! Icted, the speed of the dieselstncrator um should eot ; i exceed the i.orainal speed pNs 75 percent of the difit er.se test data are tvailable. This permits the condderadon of a between ace.inal speed and the ove:spead trip aetpoint somewhat less conservative approach, such as crersilon ce 3 % porstat of nominal, whictruisitwer,l'urtherdhe I with safety loods within the short@ne rating of the daesel- tranment following the complete loes af 1;ao shauld s not generator unit. cause the speed of the unit to attain the overspeed tnp l I

C. REGUI.ATORY p084 TION setpoint. 1

5. la Section 5.4,"Quahfication,"ofIEEE Std 3871977 Conformance with the requirements of IEEE Std 387 1977, b the qualification testing requirements of IEEE Std 3231974, "lEEE Standard Criteria for Diesel Generator Units Applied "lEEE Standard for Qualifying Class IE Equipment for as Standby Power Supplies for Nuclear power Generating Nuclear power Generating Stations,"3 should be used ,

Stations," dated June 17,1977, is acceptable for meeting subject to the regulatory position of Regulatory Guide 1.89, l the requirements of the principal design criteria and qualifica- "Qualificetion of Class IE Equipment for Nuclear Power tion testing of diesel generator units used as onsite electric plaats."

power systems for nuclear power plants subject to the following: 6. Section 5.5." Design and ApplicationConsiderations."

of IEEE Std 387 1977 pertains to design features for con.

1. When the characteristin of loads are not accurately sideration in dieselpenerator unit design. In conjunction known, such as during the construction permit stage of with Section 5.5, diesel generstor units should be designed i design, each dieselgenerator unit of an onsite power supply 1.9 2

. . , Quennectic.a of anu it squipessi for tusher Peoer i o to metehle during opennon of es cualeet poww phet Geesmiles 8tseisme," for esimmis analysis er asismie esseins !

a wou o wtas the plant 0 shut dews. The dealso sheed by agulpment meeufestuen ebeeld to used est$est O the i inelede proshiese es that the tsalas of es seen se sogdetary postales of Ragnetary Oulde 1.130. "9shesis simulate the parensens of epsuusica (esened in Sessle- Qualinsesen of Blaserie Squipuneet for Nasher Power ~

tery Gales 3.198, '9tskses itsdag et Disas6esessner Phsm," ;

unas used e omans ammes pseur systems et Mussser )

Power Plants") est seem to espanist if eessel emesme 10. The opuesama==ad by " mar"in seseen 6J.stsXe) i'

. won se to pimend es es spann, of 1885 844 3871977 sheed to easted as e togedeement.

Testanety should to esasidered in the salesetas and 11, Sessies 6J,*Sies AsseptemasTesehe,"and Gesehen d64, loestion of instrumentation sessen and estelsel compensam "Parlees testina," ef lBS50ed )81.lt?? should ts espele-(e.g., severner, starting erseems sempeassed, and es mooted by Regeistory Guide 1.198, ourell design sheed inelade seetus indisettes and eless features. lastrumentation sensero should be reedty assemAte 1

12. Sesties 4,"Refusnestesadores,"af m tsd ag7.lM7 l and, where practiesbis, designed es that their Ansposaise lists additteest appbsetts ISB5 sesoderes.The spostRe appe-and seMbreties een be serined is pense, estetty er esemptahmty of esos sofusased senadsrds has ,

^

been er we to soussed sopesesser in othersegnietwy psiden,

7. Section 3,6.2.2, "Antenatic Centrd," et M ted..

- whose appropsissa. ,

l 387 1977 pertains to estematie startup sequbeansme sad '

their relationship to other operating modse. In esebesseins j

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13. Section 6J.2, " Start and Land Aesoptease Quahn-with Section$.6.2.2,--C action," pertains to test requirements for elessi.generster !

ontiel tripe may be implemented by a t'

n'tr$. AB unit quaunsaties, la essdsaselos week tese6sn 6.3.2, !

other dieselgenerator protecthe tripe should be handled te one of two ways: Either,(1) e trip should be implemented fewer seesessful seertend4eed teses and eBowed fetures than that spesined-800 valid teses with no more than 3 with two or more independent measumments for each trip !

feuwes-may be justiSod for a diesengeneseter unh that parameter with coincident logic provisions for trip actuation. - sorties only see large esenested load tested under esquel or (2) e trip may be bypassed under socident conditions, condissees, provided as equheleet reliability /see8dsess provided the operator has sufficient time to reest appro- levelis demonstreted, priately to en abnormel diesel generator unit condition. The design of the bypees otrcuitry should satisfy the requiremones Id. In Section sJ.1," Load capshiuty Queufisetion,"of '

of IEEE Std 279 1971 et the diesel generator system level IEEE Std 3371977, the order of segvense of lead tests and should z!nolude the capability for (1) testing the status '

described in parte (1) e3d (2) shou;d be as follows: Lead and operst.JJty of the by;ess circuits,(2) sterming in the control room obNormel vetoes of all bypass parameten, and equel to the continuour reting abould be opplied it,r th ;

time seguired to ree:h ename temperature equi'ubduai, st

3) moeuelly resetting of the trip bypass function.(Chpebility i which time, the seted abort tine load shovu le applNd for i

(for sutomatic reset is noSeceptable.) ,

t pcriod of 2 'nours immediately fouowing the 2 hwr !

thort time load test, leed equal to the continuous retmg.

S. Section 3.6.3.1, "Eusveinance Syrems," of IEEE htd should be applied for 22 hours2.546296e-4 days 0.00611 hours 3.637566e-5 weeks 8.371e-6 months . ,

Mt19M pertcins to 6tetur. indicctim of (lesel-(mer eretor :

, unit conditions. In conjur.ction with Goetion $.6.3.1, fa 0, lin.t#4sffADON l order to facilitate trouMe diagrMs,the surveillance rystess 4 L .

shodd imilcate which of thc dieselgenerator protectm "

E* cept in tho96 ckers in w'nkh the sWJant propcats en tripa b gettrete 4 fiat. .

acceptr.bse e$ternettee toothed fut (f.etoplyir4 with specTM portions of the Comnussion's regulatione, the method dc.

9. In Section 6.3," Type QuCficatinn T esting Procedures senbod berein wGl be used in the evolustion of applications and Methods," ofIEEE Std 3871977, the requirements of for construction permits dec.keted after December 1979, e

IEEE Std 3441975," Recommended Practices for Seismic I

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,.. ~u RsFERENCE y h,

. l 8.3 Onsite Power Systems '

8.3.1 General DescriptTon 8.3.1.1 Alternatino Current Power System The alternating current power system serves as a standby to the offsite power system. The safety function of the alternating current power system (assuming the offsite power system is not' functioning) is to provide sufficient capacity and capability to assure that the structures, systems and components important to safety perform as intended. The objectives of our review were to determine that the onsite power system has the required redundancy; meets the single failure criterion; and has the capacity, capability and reliability to supply power to all required safety loads. Our review utilized the criteria set '

- forth in Section 8.1.1 of this report in evaluating the system. ,

The alternating current power system for each of the two units is comprised of three physically independent electrical distribution system divisions. These }(

three electrical divisions are designated as Divisions 1, 2 and 3 for each unit. For Divisions 2 and 3 of each unit a separate diesel generator is provided to power each of these electrical divisions. An additional sharedEach diesel-generator provides power to electrical Division 1 of either unit.

of the Division 2 and 3 diesel generators receives direct current control power from its respective divisional station emergency battery. The shared diesel generator may receive control power from either of the two divisions (Division 1 associated with each unit) by way of transfer circuitry. Each distribution system division includes 4160- and 00-volt load centers to accommodate the power requirements of the safety m ds. The safety loads for each unit are distributed among the three divisio in such a manner that the operation of any two divisions.is all that is required to meet minimum safety requirements. Table 8.1 depicts the divisional arrangement of the various safety systems and/or equipment.

Each of the five diesel generators and selected associated auxiliaries is located in a separate room within a seismic Category I structure and is provided with an independent source of ventilation air.

Each of the five diesel-generators has a continuous rating, 2000-hour rating, 7-day rating, and 30-minute rating of 2600 kilowatts, 2860 kilowatts, 2987 kilowatts and 3040 kilowatts respectively. Each diesel generator will be automatically started by an undervoltage signal from its respective 4160 volts emergency bus, or low reactor vessel water level, or high primary containment (drywell) pressure (provisions are also included in the design to manually

!, tart'each diesel-generator). Upon loss of offsite power, the 4160-volt emergency buses for Divisions 1 and 2 will be automatically isolated from The all supply sources and all associated 4160-volt motor loads will be tripped.

Division 3 electrical loads (the~high pressure core spray system motor and associated controls) are not tripped following the loss of offsite power to the associatet 4160-volt bus. All diesel generator sets will be connected automatically to their respective emergency bus and the safety loads will be automatically connected in a predetermined sequence to their respective diesel-generator.

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The following items address areas of concern noted during our review and ,

L provide pert'nent information concerning these areas. .

. (1)>~DieseNGenerators Prototy>e Testina for General Electric Supplied High Pressure Core Spray Diesel- 3enerators '

L j

For thel two diesel generator sets supplied by General Electric (one associated. '

with each of the two, Division 3, electrical safety divisions of the station) and attendant distribution system which includes the high pressure core. spray '

pump motors, we'have determined that the arrangement of these diesel-generator sets'does not satisfy the recommendations of Position'4 of the Regulatory; '

Guide 1.9, " Selection of Diesel-Generator Set Capacity for Standby Power Supplies," with regard to frequency and voltage variations. In response'to this concern, the applicant committed to perform a test (with the associated equipment as installed at the plant site) to demonstrate that these diesel-generator sets can start and accelerate to rated speed (with some margin) for the high pressure core spray pump motor successfully within the limiting required-time and report.their findings. The applicant provided the subject test report, General Electric Topical Report NEDO-10905-3 dated August 1979, "High Pressure Core Spray System Supply-Unit." This report was reviewed:

generically by us and found acceptable. Based on our review of this report. '

(letter dat'ed April 7,1980 from O. D. Parr to Dr. G. G. Sherwood), we conclude '

that the high pressure core spray diesel generator units as installed at'

'La Salle are acceptable.

Prototype Tests for Non-General Electric Supplied Diesel-Generators d

The three diesel generator sets which were not supplied by. General Electric,

the, applicant has documented that factory prototype testing has been performed which includes six starting tests, a sequential loading test, and the 300 start qualification test. In addition, these sets received at the factory a full load test, a 110 percent overload test, and a voltage stability and-transient response test. Also these diesel generator sets satisfy the recom-

. mendations contained in Regulatory Guide 1.9, with regard to frequency and voltage variations during loading transients. Further, during preoperational testing at the site, two additional tests which relate to margin will'be performed on each set. For one of these tests which is called " steady-state

. margin test" a load in excess of the tdal design accident loads (sum of all e

the applied. accident load blocks) are yplied to the set so as to demonstrate some margin in excess of the total design requirements. For the other test '

called " start-load margin test" a load in excess of the largest single load-.

block is applied as a step function to the set to demonstrate the start and load capability of the set with some margin.

Test results will be avM1able for our review following completion of the pre--

operational testing pre., um. The test results will be reviewed by our Office 3

of Inspection and Enforcement. We conclude that the non-General Electric-supplied diesel generators as installed at La Salle are acceptable.

8-11

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-Diesel-Generator Testina- l t

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The' applicant has: indicated i. hat periodic diesel-generator' testing will not be L p'erformed Periodic Testing in accordance with positions of Diesel-Generator Units Used C2a as OnsiteandElectric C2b ofPower Regulatory Guide 1.10 .

L:

Based on Criterion 18 of the General-Design Systems at Nuclear Power Plants."

' Criteria, it,is our requirement that high reliability must be designed into diesel-generator units an:1 maintained throughout their service lifetime by J Periodic diesel-appropriate testing, maintenance, and operating programs. l generator testing provisions set forth in Regulatory Guide 1.108 have been .l designed to provide a basis for taking corrective actions needed to maintain The provisions high inservice reliability of installed diesel generator units.

of Regulatory Guide 1,108,' including periodic testing, will be imposed as part-of La Salle Technical Specifications.

Reliability of Diesel-Generators To provide further assurance of long-term reliability of-diesel-generators, a i report prepared for the NRC, NUREG/CR-0660, " Enhancement of Onsite Emergency -

Diesel Generator Reliability" made specific recommendations on increasing the reliability of nuclear power plant emergency diesel-generators. We requested- ~

from the applicant information concerning these recommendations, and also concerning the design of the fuel oil storage and transfer system, described in the Final Safety' Analysis Report. The applicant responded in Amendments 48 j

and 49, stating how they meet or will meet the recommendations of NUREG/CR-0660 and our additional concerns.

We have reviewed these responses and have determined that conformance to the .

recommendations is as follows:

Conformance Section of this Report r Recommendation Yes 9.6.3.3 (a) Moisture in Air Start System Yes 9.6.3.5 (b) Dust and Dirt in D/G Room Partial 8.3.1.1 (c) Turbocharger Gear Drive Problem Yes 8.3.1.1 (d) Personnel Training Partial 9.6.3.4

_(e) ' Automatic Prelube Yes 8.3.1.1 (f) Testing, Test Loading and Preventive Maintenance Yes 8.3.1.1 (g) Improve Identification of Root Cause of Failures Yes 9.6.3.5 (h) D/G Ventilation and Combustion Air Systems Yes 9.6.3.1 (i) Fuel Storage and Handling 8-12 j

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Conformance- Section of"this" Report I Recommendation .

8.3.1.1 (j) 'High Tempateture Insulation for Generator Yes 9.6.3.2 L

(k) Engine Cooling Water Temperature <

L Control Yes 8.3.1.1 (1) Concrete Dust Control Partial 8.3.1.1 (m) Vibration'of Instruments and Controls-L ,

On the basis of our review we have concluded that there is sufficient assurance !

of diesel generator reliability to warrant unrestricted plant operation.through the first refueling period. However, to assure long term reliability of the-diesel-generator installations we require that the following design and procedure modificatons be implemented. o The diesel generators at La Salle have (a) Turbocnarcer Gear Drive Problem:

a turbocharger. mechanical drive gear assembly whose gear ratio is 18:1.

This drive gear assembly has not been designed to operate at no load or-light load conditions and full rated speed for prolonged periods. To improve the reliability and availability of the diesel generators on demand we require the installation of a heavy dutv turbocharger drive gear assembly with a gear ratio .of 16.8:1 as reconnended by NUREG/CR-0660.

The manufacturer,-

We require the implementation prior to the first refueling.

Electro-Motive Division of General Motors Corporation, has developed >

another heavy duty turbocharger driva gear assembly which has a gear This new gear ratio of 17.9:1 and will be availabie in the near future.

assembly will have the desired characteristics of the 16.8:1 gear assembly without reducing the engine rating as would be required with the 16.8:1 ;

assembly. Therefore, we require that a heavy duty turbocharger gear-drive assembly be installed on the diesel generators. The gear ratio may be as recommended by NUREG/CR-0660 or it may be the new 17.9:1 drive gear assembly as recommended by Electro-Motive' Division of General Motors-Corporation, provided it is available within the time limit imposed' above. ,

i (b). Automatic Prelube: This item is discussed in Section 9.6.3.4 of this

l report.

The applicant stated that some (c)- Vibration of Instruments and Controls:

monitoring instrument and controls are installed on the engine and the engina skid. It also stated that the instrumentation and controls will be inspected and calibrated periodically, and if the inspections show any -

' Explicit conformance is considered unnecessary by the staff in view of the equiv- l alent reliability provided by the design margin and qualification testing i I

requirements that are normally applied to emergency standby diesel generators.

8-13 4 .

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.;, s-detrimental effects to the instrumentation, either the calibration interval' will be reduced, shock mounts for the engine and engine skid mounted panels will be provided, or the panels will be removed from the engine and floor mounted. We find this unacceptable. We require that the controls and monitoring instrumentation be removed from the engine and .

engine skid, except for sensors and other equipment that must be directly mounted on the engine or associated piping. The controls and monitoring instruments'should be installed on a free standing floor mounted panel and located on a vibration free floor area. If the floor is not vibration free, the panel should be equipped with vibration mounts. ;

As stated above, we have concluded that there is sufficient assurance of

' diesel-generator reliability to warrant unrestricted plant operation through the first refueling period. To assure long-term reliability, the operating ,

. licenses will be conditioned to require La Salle to implement the above design.

and procedural modifications prior to startup following the first refueling outage.

'The present diesel-generator design meets the requirements of Criteria 17, 18 and 21 of the General Design. Criteria. Upon completion of the above changes <

and modifications, the design of the diesel generator and its auxiliary systems will also be in conformance with the recommendations of NUREG/CR-0660 for enhancement of diesel generator reliability, and our related guidelines and riteria. We, therefore, conclude that this will provide reasonable assurance f diesel-generator reliability through the design life of the plant.

(2) Alarms and/or Indicators for Diesel-Generator Inoperable l

In response to our concern, the applicant supplied a list of control room alarms and/or indicators pertaining to conditions that render the diesel-generator sets incapable of responding to an automatic emergency start signal.

We have reviewed this information and related electrical diagrams in accord-ance to Branch Technical Position ICSB-21, " Guidance for Application of Regulatory Guide 1.47, Bypass and Inseparable Station Indication for Nuclear L Power Plant Safety Systems," and conclude that this design is acceptable.

1 (3) Bypass of Diesel-Generator Protective Trips c To minimize the likelihood of false diesel generator trip during accident conditions, we require the La Salle design to meet the positions set forth in Branch Technical Position 1C58-17, " Diesel-Generator Protective Trip Circuit Bypass." Based on our review of selected diagrams documented in Section 1.7

.of.the Final Safety Analysis Report, we conclude that the design provides for bypassing of all diesel generator protective trips except for overspeed trips and the essential electric protective relay trips during an accident condition.

~This meets the Branch Technical Position ICSB-17 and is acceptable.

8.3.1.2 Direct Current Power Systems L The direct current power system provides the alternating current onsite emergency I power systems with control power as required. Also, it provides both motive and control power to selected safety-related equipment.

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Where protective trips ere PMvided to protect the standby dieselagenpreters free 4-E possible danses or degreestion, these protective trips c6.,*d interfenh with the

m. ..e e.fui functi.ning of the dio.ei generators .h . ther . . .e.t a h m u a., e ring en socident sendition. In nuc) ear power plant applications, the criterten shev14 he to~

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' provide stendby power when needed to sitigste the effecta of an assident sendi L.{ l rather than to protect the diesel genersters from possible damage or degradetion.:

O. BRANDf TECHNICAL PDs1710N ,

'). The design of standby diesel generator systems should retain only the engine

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' overspeed and the generator differential trips and bypees a11 other trips under accident conditten. All these trips that are bypassed f6r an'eccident condition

* ney be retained for the diesel generator routine tests.) This concept will reduce the probability of spurious trips during accident conditions and will else reduce '

the exposure of the equipment to damage free malfunctions during routine tests.

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,2.- The design should include capability for testing the status and operability of the -

bypass circuits and should alars abnormal values of all.the bypeesed para the control rees.

3. If other trips, in addition to the engine overspeed and generator differential. ;

~ 1, , ") are retained for accident conditfi[ ens, an ecceptable'desien sheeld provide *We er ]

q more independent seasurements of each of these trip parameters.' . Trip logic sh l

be such that diesel generator trip would require specific coincident logic.

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' 4. The bypass circuitry for the diesel generator protective trips should be designed to meet the requirements of !!(E Std 279. 'f g

C. R(fERENCl$

1. $ERsforSt.'tucieUnits'Iand2(operatinglicenseandconstructionpermit).

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' 2. SIR for SWES$AR-P1, Stone and Webster Corporation $tenderd Plant Design.

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3. 1885 $td 279. " Criteria for Protection Systems for. Nuclear Power Generating ,

Stations."

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?! i- 18AANCH TECM ICAL POSITION ICSS-17 1Pl8 -

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01ESEL-GENERATOR PROTECTIVE TRIP CIRCU14 8Y ASSES 7

' STP.!C68-17:(PS8)hasbeenSuperceededby

.-Position 7 of Regulatory Guide 1,9.(Revision 2)l

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8A-9 'Rev. 2 - July 1981

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ML20043B176

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