JPN-90-063, Responds to NRC Re Deviations Noted in Insp Rept 50-333/90-19.Interim Corrective Action:Temporary Procedure Change Implemented to Administratively Prohibit Concurrent Closure of Upstream Feeder Breakers Until Issue Resolved

Responds to NRC Re Deviations Noted in Insp Rept 50-333/90-19.Interim Corrective Action:Temporary Procedure Change Implemented to Administratively Prohibit Concurrent Closure of Upstream Feeder Breakers Until Issue Resolved

ML20059L193
Person / Time
Site:	FitzPatrick
Issue date:	09/18/1990
From:	Brons J POWER AUTHORITY OF THE STATE OF NEW YORK (NEW YORK
To:	NRC OFFICE OF INFORMATION RESOURCES MANAGEMENT (IRM)
References
JPN-90-063, JPN-90-63, NUDOCS 9009260203
Download: ML20059L193 (8)

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Sgtoudhar 18, 1990 a JR6-90-063 {

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k', U.S. Nuclear Regulatory Commluion -l ATTN: Document Control Desk 4 1 Mail Station P1 137 i Washington, D.C. 20555 l

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SUBJECT:

James A. FitzPatrick Nuclear Power Piet i L Docket No. 50-333 ,

RESPONSE TO NOTICE OF DEVlATION  :

INSPECilON REPORT 80 333/9019  !

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Reference:

- 1. NRC letter, J. P. Durt to W. Fernandez, dated August 14,1990, i i_

transmits inspection Report 50-333/90-19. j l- N

Dear Sir:

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In accordance with 10 CFR 2.201, Attachment I responds to the Notice of Deviation included  ;

'with NRC Inspection Report 50 333/90-19 (Reference 1). This inspe:: tion was conducted by Mr. A. Deila Greca during the period from June 25 to June 29,1990 at the James A. Fit Patrick Nuclear Awar Plant. Attachment il addresses a related open item identified during this Inspecron. ..

p If yw hette any questions regarding this matter, please contact Mr. J. B. Ellmers of my staff.

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-t Very truly yours, ,

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'/J. C. Brons Executive Vice President  ?

Nuclear Generation l {

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U. S. Nuclear Regulatory Commission  !

Post Office Box 136 Lycoming, New York 13003 Regional Administrator U. S. Nuclorr Regulatory Commission j 475 Allendab Road 'J King of Prussia, Pennsylvania 19400 l r-David E. LaBarge Project Directorate I 1 i

- CMalon of Reactor Projects 1/11 U. S. Nuclear Regulatory C,ontmission Mail Stop 14 B2 .

Washington, D. C. 20555 i i.

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, a: s i s ATTACHMENTITO JPN 9H83 1 DEVlATION As a result of the irupaction conducted during the period of June 25 through June 29,1990, and in )

I accordance with the " General Statement of Policy and Procedure for NRC Enforcement Actions,'

10 CFR Part 2, Appendix C (Enforcement Policy) (1988), the following Deviation was identified: l Sectbn 8.5.6 of the James A. FRzPatnok Nuclear Power Plant FSAR, *Selety Evaluation,"

statce that redundant emergency power distribution systems are physically and  !

electrically independent and that no automatic swnching is provided to intetoonnect the l

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redundant systems. In addition, while discussing the condnions urder which vansfer switches are used to powf/ single pieces of equipment or systems from the redundant .i emergency buses, the same section states that the power transfer equipment is designed l to meet single failure critaria. )i Cordrary to the above, at the time of the inspection, power transfer swhoh 71TS-7, if failed, could provide a path to interconnect unit substatiorm 1.25 and 1.26 in the same manner as en automatic switch. Therefore, h does not most single failure criteria, in i

. addition, the transfer swhrt was determined to be non-Class 1 E.  ?

, This is a deviation. i RESPONSE TO NOTICE OF DEVIATION The Authority does not vp with the Notic of Deviation. The Authority does not consider this condition to be a " failure to satisfy a commitment" for the following reasons: l g -!

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1. The Authority does not agree with the NRC staff's interpretation of Section 8.5.6 of the FitzPetrick FSAR.

The statement paraphrased in the Notice of Deviation refers to automatic power transfer equipment fuHilling a .'ssfoguard function" and does not apply to the transfer switch in -t question.

. The transfer switch retencd to in the Notice of Deviation is a manual transfer device in a )

l non 1E portion of the electrical system it supp!ies electrical power to the RtzPatrick Safety: l

!' Parcmeter Display System (SPDS) whloh does not fulfill a

• safeguard function.'

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While this section of the FSAR may be unclear, this sentence was not intended as a ,!

commitment that every piece of electrical power transfer equipment be single failure proof, it was never the Authority's intent to provide single failure-proof power transfer equipment throughout the plant regardless of its function or the quality standards of the system in  ;

which the equipment is installed, t

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7 1 '-  : '2. The IRC eWf has reviewed and appimed Wils arrangement wtmn tie Authertty t

"26 ' E outunited informselon describing the MtzPetrtok Safety Parameter Display System (SPOE).

The Authority described the three interfaces that leolated the FitzPatrick Salsty Parameter r Display System (SPDS) from potential ecuroes of interference in Reference 2. Although  :

L switch 71TS 7 is 'et lilustrated in Figure 1 of Reference 2, it is contained within the non-  !

l 1 Class 1E uninleyuptable power supply (UPS).- ,

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The Authority a no provided in Reference 3 spoolfic test data for the 1 E quailflod electrical  !

,, breakers includ ng the breakers in question. The results of the breaker tests indicated that C, -

the circuit breakas we qualified for salsty related application including seismic.

. The NRC reviewed and approved this configuration. In the NRC Safety Evaluation. 1

^ (Reference 4), the staff agreed with the une of Class 1E breakers to protect the interface, but lf4 m

4 it is not clear thtt the staff was referring to the interfeos between the non-Class 1E UPS and ,

the station 1E power. The NRC Soloty Evaluation, did however, conclude "that the isolation '

devloes, fiber optic cables and Class .5 circuit breakers, are quellflod isolators and are l

j acceptable for interfacing the SPDG Class 1E systems." ,

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o- 3. Failure of the non 1E trengtsr switch in a manner necessary to reconnect all three phases is not a credible overa.

l Paralleling of the redundant buses on the line side of the transfer switch due to a failure of the switon during a design basis event, would require the dislocation of the wires from the transfer switch terminals and solid reconnection of phase A of the " primary" source cable to phase A of the "altamate" cable, pnase B of the

• primary" source to phase B of the >

• altamate" souros, etc., without contacting ground. This wonario is not considered credible.

The transfer safety switch is designed and constructed so that only one source of power can <

be selected at any one timo. Considering a remote possibility that an event (e.g., seismic) .

would cause an unintentional movement, the result wouki only be that the transferable loads would be fed from the other bus.

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4.' A postulated failure of the non 1E transfer switch coincident with a failure of one of the 1E leolation breakers is not a safety concem.  ;

Postulation of a failure of the non Class 1E transfor switch oould result in either phase to-ground or phaserto phase faults on the 800V Class 1E Load Center feeders supplying the switch. As no or edit can t>e taken for the non Class 1E transfer switch, whether the fault occurs on the load side er the line side of the switch is irrelevant. .

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. During these fauits, the breakers located in the Load Centers are expected to operate and isolate the fault from the other loads in that Load Center. These breakers are properly l coordinated, so that a fault in a branch circuit such as the one feeding the transfer switch would be isolated by its corresponding breaker without jeopardizing the other loads connected to the Load Center.

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", If an additional alngle tellure ci the 800V Class 1E breaker that feeds the transfer switch is poemdened, it would not result in loss of power to the redundant bus. The failed breakw would oeues the tripping at the upsiream 000v Load Cente breakw supplying that partbular Load Center. This Load Center would be lost, but the other redundant Load Center would remain unenected. ,

The only consequence of the fault wouhl be temporary loss of power to the EPIC .

uninterruptable power supply (UPS). The EPIC system has more than 1 hour1.157407e-5 days <br />2.777778e-4 hours <br />1.653439e-6 weeks <br />3.805e-7 months <br /> backup time which is sufflolent to transfer power from primary to altamete source.

5. This configuration compiles with appropriots, applicable industry standards.

The 800V power feeders from Load Center L25 (Breaker 12504) and L26 (Breaker 12804) feed non 1E EPIC uninterruptable power supply via transfer switch 71TS 7 (Westinghouse model XNU 385). This design complies with IEEE 3841981 Section 6.1.3.3 "Routmg

.l Requirements" and 7.1.2.1, " Isolation Criteria Circuit Breaker Tripped by Fault Currents."

As indicated in the inspection report, proper ooordination exists between the main (supply) aM feeder (load) breakers of both redundant load centers, in addition, the trip units for all emergency load conter breakers are included in a periodic maintenance and calibration program.

6. The NRC's " Safety Evaluation of the James A. FitzPetrick Nuclear Power Plant *,

(Reference 4) and Supplements 1 and 2 (Reference 5 and 6) do not discuss electrical transfer equipment.'

Section 7.2.2, "Onsite Power

• of the NRC SE for the FitzPatrick plant (Reference 4),

discusses the 4kV and 800V electrical buses and concludes,

• Separation and independence of these redundant systems has been maintained." (p. 7 10).

This look of discussion shows that the qualificat,ons of electrical power transfer equipment did not form a primary basis for the conclusions delineated in the NRC's SER.

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' Summary and Conclusion .

The statement paraphrased in the Notico d Deviation is not applicable to this transler switch. The I

-j parallelmg of the . redundant Class 1E buses as a result of a tallure of the transfer switch is not .

oonsidered a credible event. The NRC staff was aware of this conllguration, details'of the breaker  :

qualifications, and test program, and eA::3+%y approved them in an SER. Electrical faults,  !

generated by an intomal failure of the transfer switch, would be cleared by the corresponding l Load Center breaker with no risk to any other load connected to the bus. Single failure of a  ;

breaker would result in tripping of the 800V Load Center breaker supplying that particular Load Center. The redundant Lead Center would remain evaliable. This oonliguration complies with ,

applicable industry standards, The failure of the transfer switch during a design beels event would not jeopardize the redundant '

C, ass 5 e. buses. The transfer switch design meets the single failure ortterion as described in

- Section 8.5.6 of the RtzPatrick FSAR and does not constitute a deviation as defined in 10 CFR 50 -

Part 2.

T Interim Correcthre Actions The Authority has implemented a temporary procedure change to administratively prohibit concurrent closure of both upstream feeder breakers until this issue is resolved. ,

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i 1. NRC letter, J. P. Durr to W. Femandez, dated August 14,1990, transmits it'.cpection Report 90 19.  !

2. NYPA letter, J. C. Brons to D. B. Vasallo, dated November 1,1985 (JPN 85 080), regarding [

request for additional information to the SPDS/ EPIC system. - ,

3. NYPA letter, J. C. Brons to the NRC, deled April 15,1987 (JPN47 021). regarding Safety i Parameters Display Electrieel Breakers. j

4. NRC letter to J. C. Brons, dated Mtych 18,1988, regardmg Safety Evaluation Aaport of the  !

FitzPatrick Safety Parameter Display System (SPDS).

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5. Supplement No.1 to the Salsty Evaluation of the James A. FitzPatrick Nuclear Power Plant, l dated February 1,1973. i 1

6. Supplement No. 2 to the Safety Evaluation of the James A. FitzPatrick Nuolear Power Plant, dated October 4,1974. . .-

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1 ATTACHMENT 11 TO JPN-9VE I Rom,to NRC inspection 50-333/9019 1

NRC inspection Report 50333/9019 idenafled other conoems not spoolfically mentioned in the j Notice of Deviation. These are addressed below. 1 Emergency Ughting System Transfer Switches I in addition to the condition desoribed in the Notice of Deviation, the inspector also noted that -

there are four other areas of the plant where a similar configuration exists. . ,

The Authority has verified by walkdown that all switches in question are non Class 1E manual I

,, transfer switches.' These switches are used to feed the Emergency Ughting System. Each . j transfer switch consists of two molded case circuit breukers. These breakers are mechanically -i interlooked, so that only one breaker can be closed at a time. These molded case breakers are l L . Installed in a single metal enclosure on either side of a metal barrier which separates the breakers.  !

Therefore, this configuration fully complies with the RtzPatrick design basis and is not a concern. l l

Automatic Transfer Switches  ;

The inspection Report also noted that one line diagrams show that one of the transfer switches  ;

y (RWTS 01) is equipped with an automatic throwover. This drawing is incorrect; all of the transfer switches in question are operated manually. A Design Change Request (DCR) has been initiated i l

to correct the affected drawings to reflect this accurately. .

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Effects of Momentary Voltage Drops in AC Circulta j The Inspection report suggested that the Authority, in its response

' consider cer*As failure modes affecting redundant equipment through transfer switches.

In particular,its evaluation should address the effects of momentary voltage drops on AC .

circuits which rely on seal in auxiliary relays and contactors for operation.'

The 30 days allotted for this response is not sufficient time to complete the detailed analyses required to answer this question. Until thic lasue can be resolved satisfactorily, the Authority has

, implemented a temporary administrative control to prohibit concurrent closure of both upstream feeder breakers.

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