ML20034F354

Provides Basis for Util Request for 80 H Temporary Waiver of Compliance from Plant TS 15.3.0 Re General Considerations

ML20034F354
Person / Time
Site:	Point Beach
Issue date:	02/22/1993
From:	Link B WISCONSIN ELECTRIC POWER CO.
To:	Bradley Davis NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION III)
Shared Package
ML20034F355	List: ML20034F354
References
CON-NRC-93-18 VPNPD-93-039, VPNPD-93-39, NUDOCS 9303030053
Download: ML20034F354 (7)

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i ENCLOSURE

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NRC-93-18 li February 22, 1993 Mr. Bert Davis, Regional Aininistrator U.S. N" CLEAR REGULATORY CO:C4ISSION Reg'icn III

'I 799 Roosevelt Road

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Glon Ellyn, Illinois 60137

Dear Mr. Davis:

i D.9CKET._50-266 AND 50-301

- i BEOUESI FOR TEMPORARY WAIVrR OF COv?LIANCE pIESEL GENERATOR OPEPABILIH

?OINT BEACH N(CLEAR FIMC ' UNITS 1 AND 2 i

The purpose of this letter is to document the.. basis for' Wisconsin Electric Power Company's request for an 80-hour Temporary Waiver of' Compliance from Point Beach Nuclear Plant Technical Specification.

" General Considerations," Specification A.

7 Section 15.3.0, HEQUIREMENT FOR WHICH A WAIVER _IS REOUESTED A suonary of the governing Technical-Specifications is as follevs:

Technical Specification Section 15'3.7, " Auxiliary Electrical Systems," Specification B.I.g al. lows one dicoel. generator to be inoperable for a period not exceeding 7 days provided the 1

other diesel generator is tested daily to ensure operability.

t'he basis f or this ' specification is to provide some limited relaxation of the single-failure criterion for' the diesels to

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allow for-periodic =aintenance and repair.

j The Point Beach diesel generators are cach sized to supply one train of power for the loads necessary to mitigato.the consequences of a design basis accident in one unit and to

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-The daily maintain the other unit in hot shutdown.

cperability check conducted on the operable diosol generator is meant to assure'that it is ready to perform safety-related j

functions.

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FEB-22-93fiON17:57 E NU01. EAR P0WER FAX NO. 4142212010 P.02?

U.S.' Nuclear Regulatory Commission February 22, 1993 Page 2 1

Technical Specification 15.3.0, "Gencral Considerations," for

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Technical Specification Section 15.3, " Limiting Conditions for Operation," requires the affected unit, which is critical, to bo placed in hot shutdown within three hours if the conditions prescribed by the limiting condition for operation (LCO).

cannot te satisfied.

Additionally, if the conditions which prompted the shutdown cannot be corrected and the LCO does not i

specify an additional time period, the unit shall bn placed into cold shutdown within 48 hours5.555556e-4 days <br />0.0133 hours <br />7.936508e-5 weeks <br />1.8264e-5 months <br />.

The basis for these general' considerations is to delincate action to be taken for l

circumstances not directly provided for in.the acyion statements of t.ho specific LCO ahd whose occurrence would I

violate the intent of the specification.

EIRCtNSTANCES SUPJOU!!DIlLG THE SITJ/1TIQN On February 15, 1993, at 0425, energency diesel generator (EDG) G01 was taken out of snrvice to perform annual EDG preventive i

maintenanco,. rotor bolt inspection, electrical as-built walkdowns/ verification, engine coolant conversion fro ' glycol to treated water, and a modification to install ground d.ection capability.

The LCO under Tochnical Specification.15.3.7.3.1.g was entered when the EDG was taken out of service.

Work was completed and return-to-cervice testing was started.on the afterncon of February 19, 1993.

During return-to-service' testing, j

the following problems were encountered:

l 1)

Blown f uses in potential transformers (pts) paused voltage regulation difficultics.

The cause bf the blown fuses was attributed to a broken cpring contact on the excitation fuse.

2)

A damaged PT (with no sparn.available) which required changoout with an unused similar PT from another portion of the diocel generator protection circuitry.

A Gol operability test was successfully performed on February 21, l

1993, in the exercise start (manual start) mode and loading of the

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machine to both Unit 1 and Unit 2 buses.

This load test was perforced in accordance with operations test procedure TS-1,

" Emergency Diecel Generator G-01 Biweekly." During the exercise start, Gol experienced a start failure alarm and fuel transfer alarm.

These alarms indicated that Gol may not be meeting its tir.ing requiroments during the exercise start; however, the diesel did start, reach rated speed, and load onto its associated buses.

The G01 diocol start f ailure alarm and fuel transfer alarm cannot provent a diesel start nor cause a diesel chutdown. 'The alarms provide indication that the start sequenco may not neet its design or established timing noquence.

Since the alarms indicate that an

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FEB-22-93 MON 17:58

YNU0il6RPCfEE FAX N0. 4142212010.

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'L U.s. Nuclear Regulatory Co= mission February 22, 1993 Page 3-b adjustment may be necessary, ve desire to further. pursue'these concerns within an extended LCO time period.

We can maintain G01 in an operable condition fcr a majcr portion of the time !needed to troubleshoot and resolve the start sequence alarms.

i A Regional Temporary Waiver of Cc pliance was granted by.NRC' Regica III at 2215 on February 21, 1993, to extend the Gol

=aintenance outage fer 60 ". curs beyond the 7. days allowed by Technical Specificatica 15.3.7.5.1.g.

Following NRC Region III granting the Temporary Waiver of Complianco, we " fast-started" G01 at 2242 on February 21, 1993, and deconstrated that it was ready to load in 4.8 seconds, which is within the 10 second requirenent specified in PBNP Final Safety Analysis Report, Section E.2.

I The present state of the PsSP erergency power sources is as follows:

a.

Diesel Generator G01 (3050 KW peak) -- Out-of-Service' b.

Diesel Generator G02 (3050 KW peak) -- Operable c.

Combustion ~urbine Generator 005 (20 MW) -- Operable d.

Temporary Diesel Generatcr G10 (1700 KW)

- Operable e.

345 KV Transmission Lines -- All 4 lines in service C

i We have reviewed the extension cf the EDG Daintenance outage based.

on the prel.iminary results of our probabilistic safety assessment (PSA) analysis.

A base case core damage frequency (CDT) was-determined assuring G01 is out-cf-service for maintenance for 6.5 days.

For this base case, the CDF is 1.19572-04 Two additional cases were analyzed, (1) assuming G01 is out-of-service for 10 days, yielding a CDF of 1.2166E-04 or an increase of 1.7% cver the base caco, and (2) assuming G01 is out-of-service for 14 days, l

yielding a CDF of 1.2403E-04 or an increase of 3.7% over the base CaSO.

Based partly on the FSA analysis, we believe the plant configuration with both units eff-line, to which the Technical Specifications would direct us at this time, would not be in the best interest of protecting the public health and safety.

There are multiple factors which determine the level of protection of the public health and safety associated with emorgency diesel generator' availability and the various operating modos of both units.

Those f actors portinent to this request f or a Temporary Waiver cf Compliance are discussed below.

The most limiting initiating event for this diesel generator configuration is the ntation blackout event.

This event assures i

the loss of of f-sito power with subsequent f ailure of the diesel generator which is nct out of service.

Placing the units in a hot io 7]

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TEM 243 M0ft 17:58'.

E' IUCLEAR POL'ER FE fio. 4142212010 P,04

-i U.S. Nuclear ' Regulatory Conmission February 22, 1993 Page 4 shutdown condition removes the turbine generators from the grid and thus reduces the reliability of off-site power.

second f actor to be considered is the availability of equipment Theprevent core damage given the initiator has occurred.

If both O

units are at pcwer when a station blackout occurs, decay heat can l

's initially rer.oved by the water in the steam generators and long by the turbine-driven auxiliary feedwater pump.

However, if a ter unit is in a conditico such that steam is not availabic when the station blackout occurs, there is no circulation capability to rctr.e decay heat from the previously shut down unit.

Therefore, the availability cf systens to renove decay heat and thus, the probability of preventing core danage during a station blackout is reduced for a unit in a cold shutdown condition.

sequence,

n addition to the above factors, ve believe the chutdown of both 2 nits is not prudent because the evolution places the units through sirultaneous transients, and therefore, increases the probability

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cf initiating an event which could challenge the engineered' safety features of the reacter protection system.

We also believe that it is prudent to maintain both PENP-units at full power due to the present condition of the Wisconsin _ Electric r

Power Company electrical systen.

At the time of our discuccion with the NRC regarding our request for a Temporary Waiver of

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Corpliance, we were purchasing approxinately' 495 MW of power. f, rom cutside sources.

We prefer to maintain purchased power at less than SCO MW due to the increased potential for systen reliability associated with purchased power IcVels of 700-800 MW.

Coal-fired plants in the Wisconsin Electric systen that are currently in caintenance or renovation outages can not be brought back into service in the chcrt term.

Thereforo, the shutdown of one or both cf the P3NP units may unnecessarily compromise the reliability of the electrical system of Wisconsin Electric.

Complicating this issue was a failed transformer located at our Oak Creek Power Plant whicn limits output on one unit and our ability to import pcVer frc: other regions.

In surnary, we believe taking both units to hot shutdown and the turbine generators of f-line as required by Technical Specification 15.3.0 is not in the best interest of public health and safety. _ We holieve that this condition warrants a temporary relief fren the requirements of Technical Specification 15.3.0 for 80 hours9.259259e-4 days <br />0.0222 hours <br />1.322751e-4 weeks <br />3.044e-5 months <br /> to begin at 0425 CST on February 22, 1993, to allow us to troubleshoot, obtain spare parts, and complete repairs to the alarm rircuitry of C01 as necessary.

We have previously discussed this situation with the NRC Senior Resident Inspector and with Mr. Bob Greger of the Region III office a t 2 0 4 9 CST on Februa ry 21, 1993.

FEB-22-03 MON 17:50 UE NUCLEAR POWER FM' N0. 4142212010 P.05 t

U.S.. Nuclear Regulatory Commission February 22, 1993 Page 5 1

i Co_ff_E1?SATORY ACTIONS I

We have taken the following. compensatory actions and will naintain.

l them during this Temporary Waiver of Ccepliance porlod:

- Combustion turbine generator G05 w'ill not be taken out of r

service and will continue to be tested twice per vcek.

- Temporary diesel generator G10 will remain available (this diesel supplies power to buses BOB'and B09 for 10 CFR SO Appendix R rcquired loads).

- Emergency diesel generator G02 vill continue to be tested daily.

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- No cafoguards or periodic surveillanco testing which could jeopardize the operating status of either operating unit.

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will be conducted.

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- No work will be scheduled in the switchyard which could

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adversely affect the 345 KV system.

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- No discretionary work on opposite train safeguards r

equipment will be scheduled.

- Troubleshooting and repair. efforts will continuo on an around-the-clock basis until the problem is resolved.

SAFETY SIGNLFICANCE AND POTINTIbL CONSFOCENCES Each energency diesel generator is sized specifically to provide power to one train of safeguards loads following a design basis accident coincident with a loss of off-site power.

Energency diesel generator G02 is operable and is capable of providing'its i

full generating capacity.

JTLST_IFICATION FOR 'DLE DURATJON OFEI _ WAIVER Uc believe the requested 80-hour time period for the waiver will be suf ficient to allow us to complete troubleshooting and repairs to G01 and allow us to return that unit to a fully operable status.

Maintenance and Engineering personnel have been working two ten-hour shifts per day since the G01 outage commenced and around-the-clock during the past weekend, so worker fatigue is also a concern.

i Based upon a successful fast start test, we could declare Gol operable.

However, we believe it is prudent to remain in the i

cxisting LCO rather than enter a subsequent LCO to pontinue troubleshooting Lhe cause of the start failure alarm and fuel transfer alarm.

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FEB-22-93 M0t1 18:00 RE h'J0 LEAP.'P02EE FM t10, 4142212010 P.06 s

Uls. Nuclear Regulatory Commiscien February 22, 1993 Page 6

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f SIGNIFICANT ltAZARDS CONSIDERATIONS t

We have reviewed this request for significant hazards considerations.

The regulati:ns at 10 CFR 50.92 essentially state that a significant hazards ccnsidcraticn is created if the action:

a Significantly increases the pretability or consequences a.

of an accident prc'.iously evaluated; b,

Creates the possibility cf a new cr different type of accident; and c.

Reduces the margin :f saf ety.

The discussion below addresses each of these three criteria and demonstrates that this Temporary 'a'aiver of CC pliance does not involve a significant hazards consideration.

As discussed above, a significant increase in'the probability or consequences of an accident previcusly evaluated will not occur if both operating units are alleved to continue steady state operation at power.

In addition, the c: Opens-atcry actions described above minimize the increase in the probability er consequences of an accident since energency power is available f rom G02 to the safety-related equipment, if necessary.

Additionally, having.botl units at power further ninimizes the inercase in the probability r

consequences of an accident by providing a core reliable off-site power source and clininating unnecessary sinultaneous unit transients.

Our actions do not create the possibility of a new or different type of accident.

Lastly, we believe that granting this Terporary Waiver of Compliance will actually prcvent a reduction in the nargin of saf oty which we believe would result frc following the LCO and proceeding with-transitionin; both units to cold shutdown, for reasons previously described.

.GYIRONMEILTAL CONSEQUX1iCIE We have determined that cperatier in this condition dces not involve a significant hazards consideration, authorize a significant change in the types cr total ancunts of any of fluent release, or result in any significant increase in individual or cumulative occupational radiatica expcsure.

Therefore, we conclude that this request meetc the categorical exclusion requirements of 10 CFR 51.22 (c) (9) and that an envircnnental inpact statement or

'negativo declaration and environnental inpact appraisal need not be e

prepared.

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lFEB-22-93 MON 18:00!-

Li NUCLEAR POWER-FAXNO.;4142252010' fP.07f

'e U.S.-Nuclear Regulatory Comminnion

. February 22, 1993

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1 STATE JLQ1EICATION STATEMF,JiT We notified the Public Service Commission of Wisconsin via i

telephone at 0837 on February 22, 1993.

We_will also notify the apprcpriate state of Wisconsin officials of the roquested; Temporary.

Waiver of Compliance'by copy of this letter in accordance-with 10 CFR 50.91{b).

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$~HMARY OF COCHUNICATIONS AND APPROVALS The P3NP Manager's Supervisory. Staff (on-site review'conmittee). ret

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and discussed this issue at.1930 on February 21, 1993, concurred

'ith the decision to requoct this Temporary Waiver of compliance, and concurred with the waiver's contents.

1 We received verbal approval of this request for a Temporary Waiver

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pliance frc: NRC Region III at 2215 CST on-February 21, 1993, j

following our telephone conversation with Mr. Bob Gregor and.othe nombers of NRC Region III and'NRC Office of. Nuclear _ Reactor

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Regulation (NRR) staff.

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~f you have any questions concerning this information, please centact u Sincerely, D

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,g Bob Link vice President Ucclear Power cc:

NBC Document Control Desk NRC Resident Inspector

?ublic Service Commission of Wisconsin dah

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