ML20115D047

Proposed Spec 2.7(2)j Re Starts of EDG During Preplanned Preventive Maint or Testing

ML20115D047
Person / Time
Site:	Fort Calhoun
Issue date:	10/09/1992
From:	OMAHA PUBLIC POWER DISTRICT
To:
Shared Package
ML20115D030	List: ML20115D029 ML20115D040 ML20115D047
References
NUDOCS 9210200197
Download: ML20115D047 (7)

Text

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. . l I t 2.0 LIMITING CONDITIONS FOR OPERATION ,

2.7 Electrical Systems (Continued) i

d. Either one of the 4.16 kV engineered safeguards buses, I A3 or I A4 may ,

be inoperable for up to 8 hours9.259259e-5 days <br />0.00222 hours <br />1.322751e-5 weeks <br />3.044e-6 months <br /> provided the operability of the diesel ,

generator associated with the operable bus is demonstrated immediately l and there are no Jnoperable engineered safeguards components associated )

with the operab!c bus.

One of each group of 4160 V/480 V Transformers (T18 3A or 4A), ,

(TIB-3B or 4B), and (TIB-3C or 4C) may be inoperable for up to 81.ours provided there are no inoperable engineered safeguards components which are redundant to components on the inoperable transformer,

f. One of the 480 V distribution buses connected to bus I A3 or connected to bus lA4 may be inoperable for up to 8 hours9.259259e-5 days <br />0.00222 hours <br />1.322751e-5 weeks <br />3.044e-6 months <br /> provided there are no inoperable safeguards components which are redundant to components on the inoperable bus. -

g. Either Group of MCC No.'s (3Al,3B1,3A2,3C1,3C) or (4A1,4A2, 4Cl,4C2) may be inoperable for up to 8 hours9.259259e-5 days <br />0.00222 hours <br />1.322751e-5 weeks <br />3.044e-6 months <br /> provided there are no inoperable sai.' guards colaponents which are redundant to components on the inoperable MCC. MCC 3C1 may be inoperable in excess of 8 hours9.259259e-5 days <br />0.00222 hours <br />1.322751e-5 weeks <br />3.044e-6 months <br /> if battery chargers No. I and No. 2 are operable.  ;

h. One of the four 120V a-c instrument buses (A, B, C or D) may be inoperable for 8 hours9.259259e-5 days <br />0.00222 hours <br />1.322751e-5 weeks <br />3.044e-6 months <br /> provided the reactor protect!ve and engineered  ;

safeguards systems instrument channels supplied by the remaining three buses are all operable,

i. Two battery chargers may be inoperable for up to 8 hours9.259259e-5 days <br />0.00222 hours <br />1.322751e-5 weeks <br />3.044e-6 months <br /> provided battery charger No.1 (EE-8C) or No. 2 (EE 8D) is operable.

J. Either one of the emergency diesel generaton (DG-1 or DG 2) may be inoperable for up to seven days (total for both) during any month, the(WWisspeinbleTesginesfed 7sfeg6ards][componeiiG provided[j$

isskiated ith~thiioperable diesel generstdWl_f one'dieselfgenerator is inoperable ithij} 8 l hours [(iegasdiessi of Shenit%inopsrableidissej spnerstbrlisl restored;to operability)iEITHERj

_(1) Stsji the other diesel generator i :.:=ted to verify operability, shutdown ;nd ccatrc!: = lcf:in the :::cm;;ic med rad there are ac incpenbic engiacend =ferund: cm;mt: am-ia cd wkh the op;mb!: dic;;l gensator OR  !

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9210200197 921009 PDR ADOCK 05000285 P PDR l

(2); : Ensure the abserice~of?cohimon'canse fforflhidleselitienbrator ,

inoperability,for t!)e other diesel ggnera'srj t

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k. Island buses 1B3A-4A,1H38-4B, and IB3C-4C may be inoperable for up to 8 hours9.259259e-5 days <br />0.00222 hours <br />1.322751e-5 weeks <br />3.044e-6 months <br /> provided there are no inoperable safeguards components which are redundant to components on the inoperable bus (es). '

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1. Either one of the 125V d-c buses No.1 or 2 (Panels EE-8F and EE-8G) may be inoperable for up to 8 hours9.259259e-5 days <br />0.00222 hours <br />1.322751e-5 weeks <br />3.044e-6 months <br />.

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! 2-34 Amendment No. 60,447 1

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1 2.0 LIMITING CONDITIONS FOR OPERATION 2.7 li]ectrical SystcIns (Continued) 2

d. Either one of the 4.16 kV engineered safeguards buses, I A3 or I A4 may be inoperable for up to 8 hours9.259259e-5 days <br />0.00222 hours <br />1.322751e-5 weeks <br />3.044e-6 months <br /> provided the operability of the diesel generator ssociated with the operable bus is demonstrated immediately and there are no inoperable engineered safeguards components associated with the operable bus.

e. One of each group of 4160 V/480 V Transformers (TIB 3A or 4A),

i (TlB-3B or 4B), and (TlB 3C or 4C) may be inoperable for up to 8 hours9.259259e-5 days <br />0.00222 hours <br />1.322751e-5 weeks <br />3.044e-6 months <br />

! provided there are no inoperable engineered safeguards components which are redundant to components on the inoperable transformer,

f. One of the 480 V distribution buses connected to bus I A3 or connected to bus I A4 may be inoperable for up to 8 hours9.259259e-5 days <br />0.00222 hours <br />1.322751e-5 weeks <br />3.044e-6 months <br /> provided there are no l inoperable safeguards components which are redundant to components on the inoperable bus. ,

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g. Either Group of MCC No.'s (3Al,3B1,3A2,1C1,3C2) or (4A1,4A2, 4Cl,4C2) may be inoperable for up to 8 hours9.259259e-5 days <br />0.00222 hours <br />1.322751e-5 weeks <br />3.044e-6 months <br /> provided there are no inoperable safeguards components which are redundant to components on

the inoperable MCC. MCC 3Cl may be inoperable in excess of 8 hours9.259259e-5 days <br />0.00222 hours <br />1.322751e-5 weeks <br />3.044e-6 months <br /> if battery chargers No. I and No. 2 are operable.

h. One of the four 120V a-c instrument buses (A, B, C or D) may be inoperable for 8 hours9.259259e-5 days <br />0.00222 hours <br />1.322751e-5 weeks <br />3.044e-6 months <br /> provided the reactor protective and engineered safeguards systems instrument channels supplied by the remaining three buses are all operable,

i. Two battery chargers may be inoperable for up to 8 hours9.259259e-5 days <br />0.00222 hours <br />1.322751e-5 weeks <br />3.044e-6 months <br /> provided battery charger No.1 (EE-8C) or No. 2 (EE-8D) is operable.

, j. Either one of the emergency diesel generators (DG-1 or DG 2) may be inoperable for up to seven days (total for both) during any month, provided there are no inoperable engineered safeguards components associated with the operable diesel generator. If one diesel generator is inoperable, within 8 hours9.259259e-5 days <br />0.00222 hours <br />1.322751e-5 weeks <br />3.044e-6 months <br /> (regardless of when the inoperable diesel generator is restored to operability) EITHER:

(1) Start the other diesel generator to verify operability, OR (2) Ensure the absence of common :ause for the diesel generator inoperability for the other diesel generator.

2-34 Amendment No. (4, 447,

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t 2.0 1lMITING CONDITIONS FOR OPERATION 2.7 &citicaLSystems (Continued)

k. Island buses IB3A-4 A,1838-48, and 183C-4C may be inoperable for up to 8 hours9.259259e-5 days <br />0.00222 hours <br />1.322751e-5 weeks <br />3.044e-6 months <br /> provided there are no inoperable safeguards components which are redundant to components on the inoperable bus (es).

1. Either one of the 125V d c buses No.1 or 2 (Panels EE-8F and EE 80) may be inoperable for up to 8 hours9.259259e-5 days <br />0.00222 hours <br />1.322751e-5 weeks <br />3.044e-6 months <br />.

m. Either one of the 125V d-c distribution panels Al 41 A or Al 41B may be inoperable for up to 8 hours9.259259e-5 days <br />0.00222 hours <br />1.322751e-5 weeks <br />3.044e-6 months <br />,

n. Either one of the 120V a-c instrumen: pnels Al 42A or Al 42B may bc ,

inoperable for up to 8 hours9.259259e-5 days <br />0.00222 hours <br />1.322751e-5 weeks <br />3.044e-6 months <br />.

l The electrical system equipment is arranged so that no single fa!!ure can inactivate enough engineered safeguards tojeopardize the plant safety. The 480 V safeguards are arranged on nine bus sections. The 4.16 kV safeguards are supplied from two buses.

The normal source of auxiliary power with the plant at power for the safeguards buses is from the house service power transformers being fed from the 161 kV incoming line with on site emergency power from either one of two diesel generators and off site standby power via the unit auxiliary transformers.(0 The loss of the 161kV incoming line renders the house service transformers (TI A-3 and TI A-4) inoperable in that the transformers cannot supply power to the 4.16kV safeguards buses l A3 and 1 A4.

Inoperability of the house seMee transformer (s) or loss of the 161kV incoming line is not reportable pursuant to 10 CFR 50.72 criteria; however, the NRC will be promptly notified of these events via the NRC Operations Center.

The two emergency diesel generators on site do not require outside power for start up or operation.

Upon loss of normal anci standby power sources, the 4.16 kV buses l A3 and 1 A4 are energized from the diesel generators. ' Bus load shedding, transfer to the diesel generator and pickup of critical loads are carried out automatically

• When the turbine generator is out of service for an extended period, the generator can be isolated by opening motor operated disconnect switch DS-Tl in the bus between the generator and the main transformer, allowing the main transformer and the unit auxiliary power transformers (TI A-1 and TI A-2) to be returned to service.m The auxiliary power transformers are not considered inoperable during these normal plant startup/ shutdown l 2-35 Amendment No. 76,147,

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4 U.S. Nuclear Regulatory Commission LIC-92-306A ATTACHMENT B

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DISCUSSION, JUSTIFICATION AND NO SIGNIFICANT HAZARDS CONSIDERATIONS f

DISCUSSION AND JUSTIFICATION t OPPD pro +

The Station Omaha Unit Public Power District No.1 Technical Spec (ifica) tion 2.7(2)j.-

poses totorevise reduce thethe Fort Calhoun number of unnecessary diesel starts by providing an alternative to starting the remaining -!

diesel generator every time a diesel ir declared inoperablo.  !

Currently Technical Specification 2.7(2 j. requires that, if either of the diesel .

generators becomes inoperable,;the othe)r diesel generator be started to-verify-  !

operability. The proposed change would-provide an alternative to. starting the '

other diesel:if it can be proven by analysis and reasoning that there is not a potential common cause for a failure in the remaining diesel- generator. The l

purpose thus providing-. of starting the other itL assurance diesel is to prove is operable to-absence performofitsicommon safety function, cause failuref -i  !

needed. In providing an alternative of ensuring no common cause failures by- t analysis and reasoning unnecessary diesel starts can be avoided when a diesel +

is declared inoperable due to routine ) replanned prever.tative maintenance or >

testing. These situations do not const'tute a failure of the' diesel _ generator and therefore an analysis is more than adequate to ensure that the remaining diesel is operable. This change is similar to guidance contained in draft NUREG- r 1432 " Standard Technical Specifications Combustion Engineering Plants," and will reduce unnecessary wear on the emergenc,y diesels. l' As _ with all amendments to the. Technical Specifications. OPPD will conduct a review of procedures upon issuance of the amendment. This review will ensure that the requirement to conduct an analysis to determine the absence of common '

cause failure is adequately proceduralized.

BASIS FOR NO SIGNIFICANT HAZARDS CONSIDERATION:

The proposed changes do not involve significant hazards considerations because ' ."

operation of Fort Calhoun Station Unit No. 1_in accordance with these changes would not:

(1) Involve a significant increase-in the probability or consequences of an accident previously evaluated.

The proposed changes only provide an alternative method of I' determining if a potential common cause failure exists when a diesel generator is inoperable. The current' method of determir.ing : the. 1 absence of a common cause failure requires.that the other diesel be  ;

started to verify o)erability. The proposed : change. .would i allow analysis and reason < ng to---determine the . absence _ of common cause  ;

failure'in situations. such as when-a diesel is declared ino l to conduct preplanned preventative maintenance or testing. perable 13

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OPPD has committed to the development of an emergency diesel  !

generator reliability program in accordance with the gufdance of l Re O.gulatory Guide 95 Reference 2 .1.155, Section 1.2 and to a target reliability of the t(arget, corre)ctive actions will be required to be taken toIf the reliability of restore the reliability of the diesel. The proposed changes would reduce the number of unnecessary diesel starts and would not affect the corrective actions which will be required to maintain a reliability of 0.95. Therefore these proposed changes do not involve a significant increase in the probability or consequences of an accident.

(2) Create the possibility of a new or different kind of accident from any previously analyzed.

It has been determined that no new or different kind of accident will be created due to the proposed changes. The proposed changes will not introduce any new or different kind of operation for plant equipment. The surveillance testing requirements for the diesel generators remain unchanged. The proposed changes only allow an alternative to starting a diesel to determine the absence of common cause failures ir order to reduce the number of unnecessary diesel generator starts. Therefore, the proposed changes do not create the possibility of a new or different kind of accident from ny pt ,viously evaluated.

(3) Involve a significant reduction in a margin of safety.

The proposed changes will not change the minimum number of diesel generators required to be operable to respond to an unlikely potential accident, the time a diesel may be out of service, or the surveillance test requirements of the diesel generators. The proposed changes only allow for an alternative to starting a diesel to determine the absence of common cause failure in the operable diesel generator when the other diesel is declared inoperable.

Therefore, the proposed chan do not involve a significant reduction in margin of safety.ges Therefore, based on the above considerations, it is OPPD's position that this 3roposed amendment does not involve significant hazards considerations as defined

. )y 10 CFR 50.92 and the proposed changes will not result in a condition which significantly alters the impact of the Station on the environment. Thus, the proposed changes meet the eligibility criteria for categorical exclusion set forth in 10 CFR 51.22 e assessment need be pre (pa)r(ed.9) and pursuant to 10 CFR 51.22(b) no environmental 2

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