ML20127B787
| ML20127B787 | |
| Person / Time | |
|---|---|
| Site: | Summer, Diablo Canyon, Callaway, 05000000 |
| Issue date: | 05/16/1984 |
| From: | Mattson R Office of Nuclear Reactor Regulation |
| To: | Eisenhut D Office of Nuclear Reactor Regulation |
| Shared Package | |
| ML082410334 | List: |
| References | |
| FOIA-85-243, RTR-NUREG-0452, RTR-NUREG-452 NUDOCS 8406270193 | |
| Download: ML20127B787 (6) | |
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ENCLOSURE 1
- 'c UNITED STATES i%s NUCLEAR REGULATORY COMMISSION
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WASHINGTO N, D. C. 20555
- 'T YAY 1613o4 MEMOP.ANDUM FOR
Darrell G. Eisenhut, Director Division of Licensing FROM:
Roger J. Mattson, Director Division of Systems Integration
SUBJECT:
STANDARD TECHNICAL SPECIFICATIONS FOR STATION BATTERIES, WESTINGHOUSE PLANTS - NUREG-0452, REV. 4 In accordance with NRR Office Letter No. 38, we are recommending that the Standard Technical Specifications (STS) for Westinghouse plants be made consistent with other vendor STS requirements for station batteries.
In the most recent version of W-STS issued in 1981 (NUREG-0452, Revision 4),
the ACTION statement for Section 3.8.2.1 was inadvertently changed by splitting the batteries and chargers into different allowable outage times.
This error results in permitting the chargers to be inoperable for an additional hour or possibly eight hours before reactor shutdown would be initiated.
This change in Westinghouse STS wa's not reviewed by DSI and is contrary to the Standard Review Plan acceptance criteria and industry practice in that batteries and their associated chargers operate in unison as a common power supply to safety loads. Therefore, we recommend that the W-STS ACTION statement for Section 3.8.2.1 be corrected to the original ACTION statement (see attachment) that combined the battery and its associated charger as a single unit for outage time purposes.
This inadvertent error in the W-STS came to DSI staff's attention during the TS review for Callaway Unit 1.
We believe that W-STS issued to Summer 1 and Diablo Canyon 1 contain this error in their respective ACTION statement sections and require corrective action.
We have consulted with the STS staff of DL on the recommended correction to the W-STS and they are in concurrence with the corrective action.
. In accordance with Item 5 of Enclosure 1 to NRR Office Letter No. 38, we request that DL incorporate this correction in the next revision to W-STS documents.
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I MAY 10 534 Darrell G. Eisenhut 2-h For further information on this subject, contact J. Knox in the Power Systems Branch on x24563.
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Enclosure:
As stated cc:
L. Rubenstein T. Novak M. Srinivasan G. Lainas
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l 3 /4. 8. 2 D.C. SCU: E5 OPE ATING l
LIMITING CONDIT!CN FC:! PEPA*I N 3.8.2.1 As a minimum tr.e fo11 ewing D.C. electrical sources shall be OPERA 3LE:
a.
(250/125)-volt Eattery tar.c ho. 1, and its associated full capac'ty charger.
b.
(250/125) volt Battery tar.< hu. 2, arid its associated full capacity charger.
ADDLICASILITY: HOOE51, 2, 3, and 4 O f* C hSf3 Cf ACTION:
,g,. g3Negg charce_ cs a.
With one of tte re:uired batte y banksginoperable, re tcre the inoperable battery bank to CFEP.ABLE' status witnin 2 hours2.314815e-5 days <br />5.555556e-4 hours <br />3.306878e-6 weeks <br />7.61e-7 months <br /> or ce in at least HGT STA.'iC3Y witnin the next 6 hours6.944444e-5 days <br />0.00167 hours <br />9.920635e-6 weeks <br />2.283e-6 months <br /> and in CCLD SH'JTDO.N within the fc11cwing 20 hears.
ig ne of t e requirec full capacity chargers inocer the urUC '** of its assoc'ated batter'
, performing Sur,eil-U 6 L lance Cecuiremr.t
...' =;w' ne nour, and at least once per
- I c-8 hours it.er_e3f.taz,--Yf-at,y Category A. i r. i. n. T. A 4.0
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This specification is intenced for 6,se on plants iith two divisions of D.C. power only. Acificati.ns may ce necessary. cn a plant-unique basis. to acc: r.ocate different cesient.
SURVEli. LANCE FECUIDEMEFS
- 4. 8. 2.1 Each (25C/125) volt battery bank and charger shall he demonstratec OPEF.AELE:
a.
At least once per 7 days ty verifying that:
1.
The parameters in Table 4.8-2 neet the Category A limits, and 2.
The total battery ter :f r.a1 voltage is greater tian or equal to (255/129)-volts en f1:at enarge.
V-ST5 2/4 8-9
E!: CLOSURE 2 E' E:TRICAL P0t-lED SYSTEMS 3/4.E.2 0.C. SOUoCES 0:EDATING LI"! TING CD*!DITION-FOR OPERATION 3.8.2.1 As a minimum, the following D.C. electrical sources shall be OPERASLE:
(250/125)-volt Battery Jank No. 1, and its associated full-capacity a.
charger, and b.
(250/125)-volt Battery Bank No. 2, and its associated full-capacity charger.
- PLICABILITY: MODES 1, 2, 3, and 4.
O.: TION:
iith one of the recuired battery banks and/or full-capacity chargers inocerable, restore the inoperable battery bank and/or full-capacity charger to OcERABLE status within 2 hours2.314815e-5 days <br />5.555556e-4 hours <br />3.306878e-6 weeks <br />7.61e-7 months <br /> or be in at least HOT STANDBY within the next 6 hours6.944444e-5 days <br />0.00167 hours <br />9.920635e-6 weeks <br />2.283e-6 months <br /> and in COLD SHUTD0UN within the following 30 hours3.472222e-4 days <br />0.00833 hours <br />4.960317e-5 weeks <br />1.1415e-5 months <br />, inis specification is intendec for use on plants with two divisions of D.C.
! power only. ~ Modifications may be necessary, on a plant-unique basis, to Laccommodate different designs.
SUR"EILLAT::E REOUIREFENTS
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4.2'.2.1 Each (250/125)-volt battery bank and charger shall be demonstrated OPERABLE:
d a.
A least once per 7 days by verifvine that:
li The parameters in Table 4.8-2 meet the Category A limits, and 21 The tctal battery terminal vcitace is greater than or ecual te (25S/129)-volts en float charge.
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3 UNITED STATES 7,
NUCLEAR REGULATORY COMMISSION jc A E
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WASHINGTON, D. C. 20555 N "... ~.'f f e*-
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JUN 19 G MEMOPR:DUM FOR:
Richard C. Lewis, Director Division of Reactor Projects Region II FROM:
Darrell G. Eisenhut, Director Division of Licensing Office of Nuclear Reactor Regulation SUEJECT:
MINI!!UM STAFFING REQUIREMENTS FOR TECHNICAL S'PECIFICATIONS As you requested in your May 23, 1984 memorandum, we have reviewed the incon-sistencies identified by one of your inspectors between the minimum staffing recuirements for technical specifications and those for emergency preparedness as recommended in NUREG-0654 and Supplement 1 to NUREG-0737.
The minimum staffing recuirements as given in Table 6.2-2 of the Standard Technical Specifications are related to minimum shift crew compositicn necessary for the continued operation of the unit for the various Operational Moces.
Additional shift staffing of a HP Technician and a five member Fire Brigade (as stated in NUREG-0654 to be required by the Tech Specs) are required by Specification 6.2.2.
Requirements for staffing in the event of an onsite emergency is to be included in the Emergency Plan, which is approved by NRC and FEMA.
The Standard Technical Specifications require that the Emergency Plan which would include staffing requirements, and the implementing procedures be reviewed by the on-site review comittee (PORC for Watts Bar), and that written procedures be established, implemented and maintained for the Emergency Plan.
The requirements of 10 CFR 50.47 state that the onsite emergency response plan must meet the standards addressed in NUREG-0654 (which would include the staffing).
Since we attempt to differentiate between operational and emergency require-ments and not to duplicate in the Standard Technical Specifications regulatory recuirements stated in the Federal regulations, we do not believe that the Standard Technical Specifications need to be changed and we conclude that there are no inconsistencies for minimum staffing requirements either in the Watts Bar Technical Specifications or in the Standard Technical Specifi-cations.
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JUN 19 E84 Richard C. Lewis,
If we can be of further assistance in this matter, please contact Fred Anderson (492-4570) in the Standard Technical Specification Section of the Standardization and Special Projects Branch.
Original sisned by Darrell G. Eised.ut Darrell G. Eisenhut, Director Division of Licensing Office of fluclear Reactor Regulation BLUE TICKET 593 DISTRIBUTICI:
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P. Hungerbuhler E. Jordan J. Taylor 5L[h ANj}i:
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July 2, 1934 TOALLLICENSEESOFOPERATINGREACTORS,APPLICANTSFORANOPERATiNG LICENSE, AND HOLDERS OF CONSTRUCTION PERMITS Gentlemen:
SUBJECT:
PROPOSED STAFF ACTIONS TO IMPROVE AND MAINTAIN DIESEL GENERATOR RELIABILITY (Generic Letter 84-15)
~As part of the proposed technical evaluation of Unresolved. Safety Issue (USI)
A 44, Station Blackout, the staff is considering new requirements that would reduce the risk' of core damage from station blackout events. The reliability.
of diesel generators has been identified as being one of the main factors affectina the risk from station blackout. Thus, attaining and maintaining high bility of diesel generators is a necessary input to the resolution of USI Plants licensed since 1978 have been required to meet the reliability goals of Regulatory Guide 1.108 for their diesel generators.
However, the staff has determined that many operating plants do not have reliability goals in place for their diesel generators. Considering the critical role diesel generators play in mitigating various transients and postulated events following a loss of offsite power, the staff has determined that there is an important need to assure that the reliability of diesel generators at operating plants is maintained at an acceptable level. The staff has detennined that the risk from station blackout is such that early actions to improve diesel generator reliability would have a significant safety benefit. Toward this objective, we have developed the following approach to assess and enhance, where necessary the reliability of diesel generators at all operating plants.
The itens covered by this letter fall into the following three areas:
1.
Reduction in Number of Cold Fast Start Surveillance Tests for Diesei Generators This item is directed towards reducing the number of cold fast start surveillance tests for diesel generators which the staff has determined results in premature diesel engine degracation. The details relating to this subject are provided in Enclosure 1.
Licensees are requested to describe their current programs to avoid cold fast start surveillance testing or their intended actions to reduce cold fast start surveillance testing for diesel generators.
2.
Diesel Generator Reliability Data This item requests licersees to furnish the current reliability of each diese1 generator at their plant (s), based en surveillance test data.
Licensees are reque,ted to provide the information requested in.
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Ef! CLOSURE 1 REDUCTI0ft I.'; NUf4BER OF COLD FAST START SURVEILLAf'CE TESTS FOR DIESEL GENERATORS Fast Start Testinc The staff has for sometime had under review and assessment methods of diesel generator testing. The sta#f has determined that many licensees use a method of testing which does not take into consideration those manufacturer reccmmended preparatory actions such as prelubrication of all moving parts and warmup procedures which are necessary to reduce engine wear, extend life and improve availability.
The existing Standard Technical Specifications recuire fast starts frcm ambient conditions for all surveillance testing which in many engine designs and operating practices subject the diesel engine to undue wear and stress on engine carts.
Corcerns were expressed by ACRS regarding the imposition of severe mechanical stress and wear en the diesel ~ engine due to frecuent cold fast starts.
Nuclear Industry related groups (INP0 and American Nuclear Insurer) have also excressed concern based on operating experience that cold fast start testirg results in incremental degradation of diesel engines and that, if proper procedures covering warmuo prelubricatien, loading / unloading etc., were taken, an improvement in reliability and availability would be gained.
Similar views have been identified by the nuclear pcwer industry and the regulatory authority l
in Sweden.
The authority in Sweden has taken corrective actions to reduce the frecuency of fast starts.
l is the staff's technical iudgement that an overall improvement in diesel engine reliability and availability can be gained by performing diesel generator j
starts for surveillance testing using engine prelube and other manufacturer l
recommended procedures to reduce enoine stress and wear. The staff has also l
determined that the demonstration of a fast' start test capability for emergency diesel generators from ambient conditions cannot be totally eliminated because tne design basis for the plant, i.e., large LOCA coincident with loss of offsite power, recnires such a capability.
l In view of the above, the staff has concluded that the frequency of fast star
- tests from ambient conditions of diesel generators should be reduced. An example of an acceptable Technical Specification to accomplish tnis goal is provided in l
the attachment to this enclosure. Licensees are requested to describe their l
current programs to evoid cold fast starts or their intended action to reduce l
the number of cold fast start surveillance tests from ambient ennditions for diesel generators.
Licensees are encouragec to submit changes to their Technical Soeci'4 cation tc acccmplish a reduction in the number of such #ast starts, i
Other Testinc Alsc, the staff is concerned regarding a number of additieral diesel generator tests that are currently being recuired by Technical Specificatiens for seme of the earlier licensed operating plants. For example, when subsystems of the e~ar;ency core cocling system on some plants are declared inoperable, the diesel cenerators are recuired to be tested.
The staff has concluded tnat excessive ie W rc resuits ir. cecradaticr cf diesel encines.
In order to make tnose few
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clants consistert wit 5 the ma,iority of the blants, it is the staff's position tnat *he recuirements for testing diesel generatrrs while emergency core cooling ecuirrent is inoceratie, ba ecleted from the Technical SnecificaH ors for sucn r W s.
The affected licersees are enccuraged to crcpese Technical Specifications tc make such changet.
l.TTAC'MNT TC E.'iCLOS'JRE 1 TYPICAL TECHNICAL SPECIFICATION SURVEILLANCE REOUIREMENTS 4.5.1.1.1 Each of tne aoove requirea incependent circuits between tne offsite transmission network and the onsite Class 1E distribution O.
system shall be:
a.
Detannined OPERABLE at least once per 7 days by verifying correct breaker alignment, indicated power availability, and b.
Demonstrated OPERABLE at least once per 18 months during shutdown by transferring (manually and automatically) unit power supply.from the normal circuit to the alternate circuit.
4.8.1.1.2 Each diesel ' generator shall be demonstrated OPERABLE:
a.
In accordance with the frequency specified in Table 4.8-1 on a STAGGERED TEST BASIS by:
1.
Verifying the fuel level in the day and engine-mounted fuel
- tank, E.
Verifying ~the fuel level E1 the fuel storage tank, 3.
Verifying the fuel transfer pump starts and transfers fuel from the storage sy. stem to the day and engine-mounted tank, 4
Verifying the diesel starts from ambient condition and accelerates to at least (900) rpm in less than or equal to 10 seconds.*
The generator volta (4160) : (420) volts and (60) = (ge and freegency shall be 1.2) Hz within (10)* seconds after the start signal.
The diesel generator shall be started for this test by using one of the following signals:
a)
Manual b)
Simulated loss of offsite power by itself.
'Tne olesei generator start (10 sec) from ambient conditions shall be performed at least once per 184 days in these surveillance tests.
All I
other engine starts for the purpose of this surveillance testing may be preceded by an engine prelube period and/or other wannup procedures recommendeo by the manufacturer so that mecnanical stress and wear on the diesel engine is minimized.
NOTE:
Bars in the margin snow changes mace to the Standard Tecnnical Specifications.
D! CLOSURE ?
DIESEL GENERATOR RELI/EILITY DATA TFr reliability of diesel generators has been idertified as one of the nair factors affectino the risk of core damage from station blackout. Thus,
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attainment and continued maintenance of high reliability for diesel cenerators is necessary to the resolution of USI A 44.
To assist the staff in assessing the current reliability of diesel generators at operating plants, licensees are recuested to report the reliability of each diesel generator at their plant fer its last 20 and 100 demands.
This should include the number o# failures in the last 20 and 100 valid demands indicatina the time history 'or these failures.
Licensees are requested to indicate whether they raintain a record which itemizes the demands ard failures experienced by each diesel generator unit, in the
's manner outlined in Regulatory Guide 1.108 position C.3.a, for each diesel generator unit. Licensees should also indicate whether a yearly data report is maintained for each diesel cenerator's reliebility. The criteria fer determining the reliability of' diesel generators is as follows:
1 a.
Valid denands and failures are to be determined in accordance with the recommendations of Regulatory Guide 1.108 position c.2.e.
b.
The reliability of each diesel generator will be calculated based on the number of failures in the lest 100 valid demands.
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3.
Diesel Generator Reliability Licensees are requested to describe their program, if any, for attaining and maintaining a reliability goal for their diesel generators. An example of a performance Technical Specification to support a desired diesel generator reliability goal has beer provided by the staff in Enclosure 3.
Licensees are requested to comment on, and compare their existing program or any proposed program with the example performance specification.
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Accordingly, pursuant to 10 CFR 50.54(f), operating reactor licensees are requested to furnish, under oath or affirmation, no.later than 90 days from the date of this letter, the information requested in Items 1 through 3 above.
Applicants for operating licenses and holders of construction permits are not required to respond.
Licensees may request an extension of time for submittals of the required info rmation.
Such a reouest must set forth a proposed schedule and justification for the delay.
Such a request shall be directed to the Director, Division of Licensing, NRR. Any such request must be submitted no later than 45 days from the date of this letter.
This request for information has been approved by the Office of Management and Budget under Clearance Number 3150-0011, which expires April 30, 1985.
Sincerely,
\\,7 s'enu,!
rres Division'of icensing
Enclosures:
1.
Reduction in Number of Cold Fast Starts for Diesel Generators 2.
Diesel Generator Reliability Data 3.
Diesel Generator Reliability a
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ENCLOSURE 3 DIESEL GENERATOR RELIARILITY Inthhstaff'songoingprogramtoresolveUSIAAa,StationBlackout, diesel generator reliability is ore of the factors used to determine the lenoth of time a plant should be able to cope with a station blackout.
If all other factors are constant, the higher reliability of the diesel generator will result
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in the lower probability cf a total loss of AC power.
Maintaining diesel generators at or above specific reliability levels is assumed in the development of the resolutien of USI A 44 The reliable operation of diesel generators should be assured by a reliability progran designed to mo'nitor, improve (if necessary), and maintain reliability at a specified level.
In view of the above, licensees are recuested to describe their diesel generator reliability improvement program, if any, for attaining and maintaining a reliability goal. The program description should address the surveillance and testing the licersee performs to demonstrate the selected diesel generator reliability. All licensees have received the staff's previous letter trans-nitting the findings of NUREG/CR-0660, " Enhancement of Onsite Emergency Diesel Generator Reliability, February 1979" identifying areas where diesel generator operational problems were occurring in general.
Licensees should consider the reconmendations of NUREG/CR-0660 in their reliability program. The staff has developed an example for a diesel generator performance Technical Specification to support the maintenance of diesel generator reliability at a specified level. The proposed performance specification encompasses certain aspects of -
the existing reouirements for surveillance testing of diesel generators stipulated in Regulatory Guide 1.108 and the qualitative recommendations of NUREG/CR-0660. This performance specification is presented, as an example, in the attachment to this enclosure.
Licensees are requested to comment on and/or compare their program with the performance specification and provide cornents for staff consideretion in finalizing surveillance testing requirements for diesel generators.
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5'_TlEILLANCE REQUIpEMENTS (Continuec) c)
Simulated loss of offsite power in conjunction with an ESF actuation test signal.
d)
An ESF actuation test signal by itself.
5.
Verifying the generator is synchronized, loaded to greater than or equal to (continuous rating) in less than or equal to
(
) seconds,* and operates with a load greater tnan or equal to (con-inuous rating) for at least 60 minutes, 6.-
Verifying the diesel generatoi is aligned to provide standby power to the associated emer'gency busses.
b.
At least once per 31 days and after each operation of the diesel where the perioc of operation was greater than or equal to I hour by checking for and removing accumulated water from the day and engine-mounted fuel tanks.
c.
At least once oer 92 days and from new fuel oil prior to additional to,the storage tanks by verifying that a sample obtained in accordance witn ASTH-0270-1975 has a water and sediment content of less than or ecual to,05-volu6e percent and a kinematic viscosity
@ 40*C of greater than. or equaT to 1.9 but less than. or equal to 4.1 when tested in accord'ance wi.th ASTM-0975-77, and an imourity level of less than 2 mg. of insolubles per 100 ml. when tested in accordance with ASTM-0-2274-70'.
c.
At least once per 18 months, during shutdown by:
1.
Subjecting the diesel to an inspection in accorcance with proceoures prepared in conjunction with its manufacturer's recommendations for this class of standby service,.
2.
Verifying the generator capability to reject a load cf greater than or ecual to (largest single emergency load' kw while maintaining voltage at (4160) : (420) volts anc frequency at (60) : (1.2) H: (less than or ecual to 75!. Of the difference between ncminal speed and the overspeed trip setooint, or 15'. above nominal whicnever is less).
2.
Verifying the generator capability to reject a load of (continucus ra-ing) kw without tricoing.
The generator voitage snali nct exceec (4784) volts during and following the Icac rejection.
See f ootno e en previcas rage
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a ATTACHMENT TO ENCLOSURE 3 EXA'*PLE OF DIESEL GENERATOR PERFORMANCE TECHNICAL SPECIFICATION Backcround Review of LER data gathered as part of thb ' staff's study of USI A 44, Station i
Blackout, indicates the median value of diesel generator reliability at operating I
plants to be 0.98/ demand with about 75% of diesel generators currently in service having a reliability of 0.95/ demand or greater. The following is an elacoration of the example-perfomance Technical Specification proposed to maintain reliability levels in this' range:
Reliability Program 1.
Reliabi.lity Gcais The staff's pre osed resolution of USI A 44 currently under development would provide guidance for plants to maintain diesel generator reliability at or above specified levels (0.95 being the minimum desired level).
In order to assure that this level is achieved anc maintained, a surveillance test program is necessary. Base ~d on surveillance testing, should a diesel generator's reliability fall below a spec.ified level, certain actions should be taken as preser.ted in the next section.
2.
Reliability Level ~ Remedial Actions l
The reliability of each diesel generator is based on the number of failures in the last 100 valid demands, with appropriate remedial acticns as follows. Note that "P" is defined as the probability of failure per demand per diesel.
t L
PLANT GROUP RELIABILITY ACTION u
A (1-P)l.95 Continue surveillance testing t
at 31 day interval.
Increase surveillance testino per Table l
4.8.1 of Appendix A if the failures in the last 20 tests L
were > 2.
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.95 '> (1-P).h 0.90 Increase surveillance testing per Table 4.8.1 of Appendix A and take action per Table 4.8.2 e
of Appendix A.
C (1-P)d.90 Discualify DG.
Requalify DG in accordance with Table p
4.8.2 Appendix A.
T,e :f qsel generat: wcule remain incoerable %m the time of the last failure t"cugh the period reovired for corrective action and until the first subsequent valic successful ter-is completed.
LN__-_--_-______
. 3.
Surveillance Test Frequency In order to meet the timeliness goal, a normal test frequency is established and a criterion for increasing the test frequency is necessary to determine whether a major degradation in reliability is indicated.
e.
Normal plant surveillance - each diesel generator unit should be tested at a frequency which is in accordance with the manufacturer's recommendations, but in no case should the time ~between tests be greater than 31 days.
b.
Accelerated plant surveillance - whenever a diesel generator unit has experienced two or more failures in the last twenty demands, the maximum time between tests should be reduced to seven days. This test frequency should be maintained until-seven consecutive failure-free demands.have been performed and the number of failures in the last 20 demands has been reduced to one or less. Two failures in 20 demands is a failure rate of 0.1, or the threshold of acceptable diesel generator performance, and hence may be an early indication of degradation of the reliability of a diesel generator. However, when considered in the light of a long history of tests, two failures in the last 20 demands may only be a statistically probable distribution of two random events.
Increasing the test frequency will allow for a more timely accumulation of additional test data upon which to base judgment of the reliability of the unit.
4.
Remedial Action Criteria If the number of failures in the last twenty valid tests is three or more or in the last 100 valid tests is six or more, the licensee should
.within 14 days prepare and maintain a report describing the reliability improvement program at the facility which includes, but is not limited to; 1) the implementation of NUREG/CR-0660 recemrnendations, and 2) perform a reliabilty assessment of the offsite and onsite power system.
(See Table 4.8.2 of Appendix A for details regarding action required).
5.
Requalification Criteria If the number of failures in the last twenty valid tests is five or more, or in the last 100 valid tests is 11 or more, the affected unit would be disoualified from nuclear service and subjected to a requal-ification program.
A requalification program would be a series of 14 successful. consecutive tests without a failure.
The licensee would perform seven consecutive successful demands without a failure within 30 days of the diesel generator being restored to operable status and 14 consecutive demands without a failure within 75 days of the diesel
' generator being restored to operable status.
Refer to Attachment 2 te Table 4.8-2 of Accendix A for criteria.
Two attempts would be allowed to achieve the acceptable test series.
During recualification testing, a diesel generator unit would not be tested more frecuently than once in any 24-hour interval.
. 6.
Failure to Recualify L Diesel Generator If the diesel generator is rot requalified as defined above, the unit would be declared inoperable and the action statement in the plant Technical Specification for one diesel generator inoperable should be followed immediately.
7.
Diesel Generator Inoperability Limits The staff has determined that the allowable out-of-service period for a diesel generator should be in excess of the current 72 hour8.333333e-4 days <br />0.02 hours <br />1.190476e-4 weeks <br />2.7396e-5 months <br /> Technical Specification limit, while at the same time placing a yearly limit upon the total cumulative time that a plant may operate'with one of the diesel generators inoperable.
By placing an individual limit on maximum inoperable time for a diesel generator and'a cumulative limit of inoperability :f the onsite power system, a framework is established within which flexibility is provided to allow a licensee to best optimize planned and unplanned
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service of diesel generators at a plant. This would limit plant risk from station blackout at the same tine allowing flexibility for any given outage. Licensees may propose a total cumulative outage time for diesel generators in the Technical Specification along with the basis for the outage time chosen.
8.
Valid Demands'and Failures Valid' demands and failures used in the above paragraphs should be determined in accordance with the recommendations of Regulatory Guide 1.108, position C.2.e.
9.
Reliability Records i
A record should be maintained in accordance with the recommendations of Regulatory Guide 1.108 position C.3.a for each diesel generator unit at a site which itemizes the demands and failures experienced by the diesel (See also Attachment 1 to Table 4.8.2 of Appendix A) generator unit.
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APPENDIX A TYPICAL TECHNICAL SPECIFICATIONS 3/4.8 ELECTRICA'_ POWER SYSTEMS 3/4.8.1 A.C. SOURCES OPERATING LIMITING CONDITION FOR OPERATION 3.8.1.1 As a minimum, the following A.C. electrical power sources shall be OPERABLE:
Two physically independent circuits between the offsite a.
transmission network and the onsite Class 1E distribution system, and b.
Two separate and independent diesel generators, each with:
1.
Separate day and engine-mounted fuel tanks containing a minimum volume of gallons of fuel, 2.
A separate fuel storage syste'm conta'ining a minimum volume of gallogs of fuel, and 3.
A separate fuel-transfer pump.
APPLICABILITY:
MODES 1, 2, 3, and 4 ACTION:
a.
With an offsite circuit of the above required A.C. electrical power sources inoperable, demonstrate the OPERABILITY of the remaining A.C. offsite source by performing Surveillance Requirement 4.8.1.1.1.a within 1 hour1.157407e-5 days <br />2.777778e-4 hours <br />1.653439e-6 weeks <br />3.805e-7 months <br /> and at least once per 8 hours9.259259e-5 days <br />0.00222 hours <br />1.322751e-5 weeks <br />3.044e-6 months <br /> thereafter; and Surveillance Requirement 4.8.1.1.2.a.4 within 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br />; restore at least two offsite circuits and two diesel cenerators to OPERABLE status within 72 hours8.333333e-4 days <br />0.02 hours <br />1.190476e-4 weeks <br />2.7396e-5 months <br /> or be in at least HOT STANDBY within the next 6 hours6.944444e-5 days <br />0.00167 hours <br />9.920635e-6 weeks <br />2.283e-6 months <br /> and in COLD SHUTDOWN within the following 30 hours3.472222e-4 days <br />0.00833 hours <br />4.960317e-5 weeks <br />1.1415e-5 months <br />.
NOTE: The modified Standard Technical Specification is intended as an exarole of chances due to the reduction in numoer of fast starts
~
and diesei generator reliability imorovement program surveillance requirements.
Bars in the margin show changes for those portions of tecnnical scecifications associated with these two items.
It is necessary for licensees to incorporate these changes into existing piant tecnnical specification upon implementatinn of these two items.
. ACTION:
(Continued) b.
With a diesel generator of the above required A.C. electrical power sources inoperable,* demonstrate the OPERABILITY of the A.C. offsite sources by perfoming Surveillance Requirement 4.8.1.1.1.a within 1 hour1.157407e-5 days <br />2.777778e-4 hours <br />1.653439e-6 weeks <br />3.805e-7 months <br /> and at least once per 8 hours9.259259e-5 days <br />0.00222 hours <br />1.322751e-5 weeks <br />3.044e-6 months <br /> thereafter; and Surveillance Requirement 4.8.1.1.2.a.4 within 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br />; restore diesel generators to OPERABLE status within
( A**) days *** or be in at least HOT STANDBY within the next 6 hours6.944444e-5 days <br />0.00167 hours <br />9.920635e-6 weeks <br />2.283e-6 months <br /> and in COLD SHUTDOWN within the following 30 hours3.472222e-4 days <br />0.00833 hours <br />4.960317e-5 weeks <br />1.1415e-5 months <br />. At the number of failures for the inoperable diesel indicated in Table 4.8-2 perform the Additional Reliability Actions prescribed in Table 4.8-2 and its attachments.
With one offsite circuit and one diese'l generator of the above c.
recuired A.C. electrical powe.r sources inoperable, demonstrate the OPERASILITY of the remaining A.C. offsite source by performing Surveillance Requirement 4.8.1.1.1.a within 1 hour1.157407e-5 days <br />2.777778e-4 hours <br />1.653439e-6 weeks <br />3.805e-7 months <br /> l
and at least once per 8 hours9.259259e-5 days <br />0.00222 hours <br />1.322751e-5 weeks <br />3.044e-6 months <br /> thereafter and Surveillance Requirement 4.8.1.1.2.a.4within8 hours;restoreatleastonej of the inoperable sources to OPERABLE status within 12 hours1.388889e-4 days <br />0.00333 hours <br />1.984127e-5 weeks <br />4.566e-6 months <br /> or be in at least HOT STANDBY within the next 6 hours6.944444e-5 days <br />0.00167 hours <br />9.920635e-6 weeks <br />2.283e-6 months <br /> and in COLD SHUTDOWN within the following.30 hours3.472222e-4 days <br />0.00833 hours <br />4.960317e-5 weeks <br />1.1415e-5 months <br />.
With the diesel generator r.estored to OPERABLE status, follow Action Statement a.
With'the offsite circuit restored to OPERABLE status, follow Actjon Statement b.
- A diesel generator shall.be considered to be inoperable from the time of failure until it satisfies the recuirements of Surveillance Requirement 4.8.1.1.2.4 ELECTRIC POWER SYSTEMS
- The ma'imum time that an individual diesel generator may be inopersble (A) shall be established by the licensee based on the manufacterer's recommendations and previcus maintenance anc repair experience.
Every reasonable effort shall be made to restore individual diesel generators to operable status within that time period (A).- Every reasonable effort shall be interpreted to mean that diagnosis and repairs are to begin immediately and are to continue uninterrupted until the diesel generator is declared operable or an orderly retreat to cold shutdown is initiated.
- The maximum total cumulative time that the diesel gene ators of the onsite emergency AC power system may oe in the INOPERABLE status in a given year shall be proposed by the licensee.
. l ACTION:
(Centinued) d.
With two of the above required offsite A.C. circuits inoperable, demonstrate the OPERABILITY of two diesel generators by performing Surveillance Requirement 4.8.1.1.2.a.4 within 8 hours9.259259e-5 days <br />0.00222 hours <br />1.322751e-5 weeks <br />3.044e-6 months <br /> unless the diesel generators are already operating; restore at least one of the inoperable offsite sources to OPERABLE status within 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br /> or be in at least HOT STANDBY within the next 6 hours6.944444e-5 days <br />0.00167 hours <br />9.920635e-6 weeks <br />2.283e-6 months <br />.
With only one offsite source restored, follow Action Statement a.
e.
With two of the above required diesel generators inoperable, demonstrate the OPERABILITY of. two offsite A.C. circu.its by performing Surveillance Requirement 4.8.1.1.1.a within 1 hour1.157407e-5 days <br />2.777778e-4 hours <br />1.653439e-6 weeks <br />3.805e-7 months <br /> and at least once per 8 hours9.259259e-5 days <br />0.00222 hours <br />1.322751e-5 weeks <br />3.044e-6 months <br /> thereafter; restore at least one of the inoperable diesel generators to GPERABLE status within 2 hours2.314815e-5 days <br />5.555556e-4 hours <br />3.306878e-6 weeks <br />7.61e-7 months <br /> or be in at least HOT STANDBY within the next 6 hours6.944444e-5 days <br />0.00167 hours <br />9.920635e-6 weeks <br />2.283e-6 months <br /> and in COLD SHUTDOWN within the followino 30 hours3.472222e-4 days <br />0.00833 hours <br />4.960317e-5 weeks <br />1.1415e-5 months <br />. With one diesel generator unit restored, follow Action Statement b and d.
5 6
e a
t
. SURVEILLANCE REQUIREMENTS 4.8.1.1.1 Each of the above required independent circuits between the offsite transmission network and the onsite Class 1E distribution system shall be:
a.
Determined OPERABLE at least once per 7 days by verifying correct breaker alignments, indicated power availability, and b.
Demonstrated OPERABLE at least once per 18 months during shutdown by transferring (manually and automatically) unit power supply from the normal circuit to the alternate circuit.
4.8.1.1.2 Each diesel generator shall be demonstrated OPERABLE:
a.
In accordance with the frequency specified in Table 4.8-1 on a STAGGERED TEST BASIS by:
1.
Verifying the. fuel lefel in the day and engine-mounted fusi
- tank, 2.
Verifying the fuel level in the fuel storage tank, 3.
Verifying the fuel transfer pump starts and transfers fuel from the storage system to the day and engine-mounted tank, 4
Verifying the diesel starts from ambient condition and accelerates to at least (900) rpm in less than or equal to-10 seconds.* The generator voltage and frequency shall be (4160) : (?20) volts and (60) : (1.2) Hz within (10) seconds after the start signal.
The diesel generator shall !
be started for this test by using one of the following signals:
a) Manual b)
Simulated loss of offsite power by itself.
- ine oiesei generator start (10 sec) from ambient conditions shall be performed at least once per 184 oays in these surveillance tests.
All other engine starts for the purpose of this surveillance testing may be preceded by an engine prelube period ano/or other warmup procedures recommended by the manufacturer so that mechanical stress and wear on the diesel engine is minimized.
i i
I
l SURVEILLANCE REOUIREMENTS (Contined) c)
Simulated loss of offsite power in conjunction with an ESF actuation test signal.
d) An ESF actuation test signal by itself.
5.
Verifying the generator is synchronized,. loaded to greater than or equal to (continuous rating) in less than or equal to ( ) seconds,* and operates with a load greater than or
. equal-to (continuous rating) for at least 60 minutes, e
~
6.
Verifying the diesel generator is aligned to provide standby power to the associated emergency busses.
b.
At least once per 31 days and after each operation of. the diesel where the period of operation was greater.than or ecual to I hour by checking for and removing accumulated water from the day and engine-mounted fuel tanks.
c.
At least once per 92 days and from new fue.1 oil prior to addition to the storage tan 4s by ve'rifying that a sample r
obtained in accordance'with ASTM-0270-1975 has a water and sediment content of less than or equal to.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-02274-70.
d.
At least once per 18 months, during shutdown, by:
1.
Subjecting the diesel to an inspection in accordance with procedures prepared in conjunction with its manufacturer's reconnendations for this class of standby service.
2.
Verifying the generator'cacability to reject a load of greater than or equal to (laroest single emergency load) kw whilemaintainingvoltage.at(4160)=(420) volts and frecuency at (60) : (1.2) Hz (less than or equal to 75i; of the difeerence between nominal speed and the overspeed trip setpoint, or 15% above nominal whichever is less).
3.
Verifying the generator cacability te reject a load of (continuous rating) kw witnout trioping.
The generator voltage shall not exceed (4784) volts during and following the load rejection.
"See footnote on page 4
6-SURVEILLANCE REOUIREMENTS (Continued) 4 Simulating a loss of offsite power by itself, and a)
Verifying de-energization of the emergency busses and load shedding from the emergency busses.
b)
Verifying the diesel starts on the auto-start signal, energizes the emergency busses with permanently connected loads within (10) seconds, energizes the auto-connected shutdown. loads through the load sequencer and operates,for greater than or equal to 5 minutes while its generator is loaded with the shutdown loads. After energization, the steady state voltage and frequency of the emergency busses shall be maintained at (4160) : (420) volts and (60) = (1.2) Hz during this test.
5.
Verifying that on an ESF actuation test signal, without loss of offsite power, the diesel generator starts on the auto-s~ tart signal and operates on standby for greater than or equal,to 5 minutes.
The generator voltage and frequency shall be (4160) : (420) volts and (60)
(1.2) Hz within (10) seconds a.fter the auto-start signal; the steady state generator voltage,and frequency shall be maintained within these limits during this test.
6.
Simulating a loss of offsite power in conjunction with an ESF actuation test signal, and a)
Verifying de-energization of the emergency busses anc load shedding from the emergency busses.
b)
Verifying the diesel starts on the auto-start signal, energizes the emergency busses with pennanently connected loads within (10) seconds, energizes the 5
SURVEILLANCE REOUIREMENTS (Continued) auto-connected emergency (accident) loads through the load sequencer and operates for greater than or ecual 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) : (420) volts and (60) = (1.2) Hz during this test.
c)
Verifying that all automatic diesel generator trips, except engine overspeed and generator differential, are automatically bypassed upon loss of voltage on the emergency bus concurrent with a safety injection actuation signal.
7.
Verifying the diesel generator operates for at least 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br />. During the first 2 hours2.314815e-5 days <br />5.555556e-4 hours <br />3.306878e-6 weeks <br />7.61e-7 months <br /> of th.is test, the diesel generator shall be loaded to greater than or equal to (2-hour rating) kw and during the remaining 22 hours2.546296e-4 days <br />0.00611 hours <br />3.637566e-5 weeks <br />8.371e-6 months <br /> of this test, the diesel generator shall. be loaded to greater than i
or equal-to (continuous rating) kw.
The generator voltage within (10) y shall be (4160) :
and frequenc (420) and (60) = (1.2) Hz seconds after the start signal; the steady state generator voltage and frequency shall be maintained within these limits during this test. Within 5 minutes after completing this 24-hour test, perform Surveillance Requirement 4.8.1.1.2.d.7.b.
8.
Verifying that the auto-connected loads to each diesel generator do not exceed the 2000-hour rating of kw.
9.
Verifying the diesel generator's capability to:
a) Synchronize with the offsite power source while the generator is loaded with its emergency loads ucon a simulated restoration of offsite power, b)
Transfer its loads to the offsite power source, and c) Se restored to its standby status.
10.
Verifying that with the diesel generator operating in a test mode, connected to its ous, a simulatec safety
. injection signal overricas the test mcde by (1) returning the diesel generator to standby operation and (2) automatically energi:ing the emergency loads with offsite power.
n
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. ELECTRIC POWER SYSTEMS Table 4.8.1 DIESEL GENERATOR TEST SCHEDULE Number of Failure in Last 20 Valid Tests
- Test Frecuency f= 1 At least once per 31 days Jr 2 At least once per 7 days **
- Criteria for oetermining number of failures and number of valid tests shall be in accordance with Regulatbry Position C.2.e of Regulatory Guide 1.108, Revison 1, August 1977, where the number of tests and failures is determined on a per diesel generator basis.
For the purposes of this test schedule, only valid tests conducted after the OL issuance date shall be included in the computation of the "last 20 valid tests."
- This test frecuency shall be maintained until seven consecutive failure free demands have been performed and the number of failures in the last 20 valid demands has been reduced to one or less.
9_
TABLE 4.8-2 ADDITIONAL RELIABILITY ACTIONS No. of failures No of failures in last 20 in last 100 valid test valid tests Action 3
6 Within 14 days prepare and maintain a report for NRC audit describing the diesel ge,nerator reliability improvement program
, implemented at the site.-
Minimum requirements for the report are indicated in Attachment I to this table.
5 11 Declare the diesel generator inoperable.
Perform a requali-fication test program for the affected diesel generator.
{
Requelification test program requirements are indicated in to this table.
e
ATTACHMENT 1 TO TABLE 4.8-2 REPOPTING REOUIREMENT
-As a minimum the Reliability Improvement Program report for NRC audit shall include:
a) a summary of all tests (valid and invalid) that oc~ curred within the time period over which the last 20/100 valid tests were performed b) analysis of failures and determination of root causes of' failures c) evaluation of each of the recommendations of NUREG/CR-0660,
" Enhancement of Onsite Emergency Diesel Generator Reliability in Operating Reactors," with respect to their application to the Plant d) identification of all actions taken or to be taken to 1) correct the root causes of failures defined in b) above and 2) achieve a general improvement of diesel generatcr. reliability e) the schedule for implementation Q( each action from d) above f) an assessment of the existing rehability of electric power to engi.neered-safety-feature equipment Once a licensee has prepared and maintain an initial report detailing the diesel generator reliability improvement program at his site, as defined above, the licensee need prepare only a supplemental reocrt within 14 days after each failure during a valid demand for so long as the affected diesel generator unit continues to violate the criteria (3/20 or 6/100) for the reliability improvement program remedial action.
The sucolemental report need only update the failure / demand history for the affected diesel generator Unit since the last report for that diesel gene-ator. The succlemental report shall also present an analysis of the failure (s) with a root cause determination, if possible, anc shall celineate any further procedural, hardware or operational changes to be incorporated into the site diesel generator improvement progran and the schedule for inclementation of those changes.
In addition to the above, submit a yearly data report on the diesel genera tor. reliabili ty.
1
f
- : i ATT* CHMENT 2 TO TAS'.E 4.8-2 DIESEL GlT EATOR P.EGUALIF; CATION PROGRAM 4
(1)
Perfom seven consecutive successful demands without a failure within 30 days of diesel generator being restored to operable status and fourteen consecutive successful demands without a failurs within 75 days of diesel generator of being restored to operable status.
(2)
If a failure occurs during the first seven tests in the.
recualification test program, per#om seven successful demands witnout an additional failure within 30 days of diesel generator of being restored to operable status.and fourteen consecutive.
successful demands without a failure within 75 days of being restored to oceraole status.
(3)
If a failure occurs during the second seven tests (tests 8 through
- 14) of.(1) above, perform fourteen consecutive successful demands without an additional failure within 75 days of the failure which occurred during the requalification testing.
(4)
Fol, lowing the sec.ond failure during the requalification test program, be in'at least HOT STANDBY within the next 6 hours6.944444e-5 days <br />0.00167 hours <br />9.920635e-6 weeks <br />2.283e-6 months <br />
, (
and COLD SHUTDOWN within the fol}owing 30 hours3.472222e-4 days <br />0.00833 hours <br />4.960317e-5 weeks <br />1.1415e-5 months <br />.
(5)
During recualification tetting the diesel generator should not be tested more frecuently than at 24-hour intervals.
After a diesel generator has been successfully requalified, subsequent repeated requalification tests will not be required for that diesel generator under the following conditions:
(a) The numoer of failures in the last 20 valid demands is less than 5.
(b) The number of failures in the last 100 valid demands is less than 11.
(c)
In the event that following successful requalification of a diesel genera or, the nur.ter of failures is still in excess of the remedial action criteria (a and/or b above)~ the following exceptior will be allowed until the diesel generator is no longer in violation of the remedial action criteria (a and/or b above).
Requalification testing will not be recuirec croviced that after each valid demane the numoer c' failures in tne last 20 and/or 100 valid demands has not increased.
Once One ciesei generator is no longer in violation or tne re.ecial action criteria scove the provisions of tnose criteria alone will prevail.
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