ML20214K915

Requests NRR Review of 860915 LER 86-15 Re Emergency Diesel Generator Undervoltage Condition During Block Loading Sequence Following LOCA & Loss of Offsite Power.Suppl to LER Will Address FSAR Issues & Provide Addl Info

ML20214K915
Person / Time
Site:	Crystal River
Issue date:	04/30/1987
From:	Reyes L Office of Nuclear Reactor Regulation
To:	Varga S Office of Nuclear Reactor Regulation
References
NUDOCS 8705290089
Download: ML20214K915 (5)

Text

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~ ep' APR 301997

/ MEMORANDUM FOR: Steven A. Varga, Director, Division of Reactor Projects I/II, NRR FROM: Luis A. Reyes, Director, Division of Reactor Projects

SUBJECT:

REQUEST FOR EVALUATION OF CRYSTAL RIVER, UNIT 3 EMERGENCY DIESEL GENERATOR UNDERVOLTAGE CONDITION DURING BLOCK LOADING

References:

1. Licensee Event Report (LER) 86-15 of September 15, 1986.

2. Dockei 50-302 Final Safety Analysis Report, Section 8.

Per reference'1. and the enclosures, Crystal River Unit 3 has identified a potential diesol undervoltage problem during its block loading sequence following a LCCA and Loss of Off-Site Power (LOSP). As noted in the enclosures, a supplemental LER is forthcoming from the licensee which should provide

- additional information on the condition and it should address aspects of reference 2.

Request that NRR review this issue an'd advise us of your position.

ORIGINAL SIGNEO BY VIRGIL L BROWNLEE & l Luis A. Reyes

Enclosures:

1. FPC Interoffice Correspondence dated April 7, 1987

2. Gilbert / Commonwealth Correspondence dated April 16, 1987 bec w/encls: l

/ T. Stetka, Crystal River Resident Inspector B. Wilson, Region II Project Section Chief  ;

A. Herdt, Region II l Engineering Branch Chief Document Control, Region II 8705290089 870430II CONTACT: PDR ADOCK 05000302 B. Wilson P PDR~

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INTEROFFICE CORRESPONDENCE Nuclear Safety & Rellability . NA2F 4499 Ofnce MAC Telephone susJact: Reportability of 480V Second Level Undervoltage Relaying (SLUR) Situation To: G. W. Castleberry DATE: April 7,1987 PER 87 0064 l In his letter (NEA 87 -0219) to you, dated March 18, 1987, Matee Rahman outlined a previously unreviewed situation involving the SLUR and its impact upon the emergency block loading of certain 480V loads.

To make an accurate determination of reportability on this matter, I will need Nuclear Operations Engineering to answer the following questions:

1. Since SLUR can cause DCP-1 A, DCP-18, CHHE-1 A, CHHE-18, and CHHE-2 to all load as block one components, will this improoet load sequencing cause the EDG voltage to droop outside of design

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basis? For example, outside of the basis upon which the SLUR actuation setpoint was established.

2. Does this improper load sequencing in itself create a condition tnat is outside the plant design basis?

3. Because it is an unreviewed situation does it create a condition that significanuy compromises plant safety? For example, is the significance great enough to consider the EDCs inoperable?

4. Does the level of significance warrant immediate corrective action?

If not, then explain why.

It is important that the significance of the unreveiwed situation and/or the conditions outside of our design basis be identified and evaluated in a timely manner. Further delays will only create the perception of an unresponsive attitude toward a potential safety issue.

Please provide a response to the above que il 20,1987 so that the matter can be addressed in the supplement t LER 86-15, ' May 1,1987.

I have enclosed copies of the applicable section to NUREG-1022 (LER Rule) for your information.

/m J Tom Metcalf Nuclear Operations Technical Advisor

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, , gog 04/16/87 15:34 P. t * . e m-a Enclosure 2 Gilbert / Commonwealth engineersandconvitents oitost? Allo (tAtti.thC P o. box latt neecq.PA 19601 *Tet.21s.7?l.1600'Can e Grasooteleu $34431 April 16, litt FCl 8378 W.O. 04-8800 017 SA #00054 Mr. M. Del Castillo Nuclear Project Management Engineer Florida Power Corporation P. O. Box 14041/C31 St. Petereburg, Florida 33733 Attentlom Mr. M. U. Rahman Rei Crystal River Unit 3 Diesel Generator Loading Small Account Request 817-84 Ref:

Action By: N/A Deat Mr. Del Castillo Per the request of your Mr. M. U. Rahman G/C, Inc. has reviewed Mr. T. Metcalf's memorandum of April 7,1987 to Mr. G. W. Castleberry and offer the following responses to the questions posed Questian #1 G/C, Inc. has reviewed the loading of the diesel generator (calavlation SS-CR3-033, dated February 10, 1972 and FCS 846 dated November 20, 1979) and have determined the voltap proille on the ESA bus with CHHE-1A and DCP 1A being started coineident ,

with Bloci i to be sa follows:

l

% Minimum Voltage Recover Time To (4000 V Easa) rat ed _Voltara Block 1 87.1 3.35 Block 1 77.0 1.86 Block 8 74.9 1.80 Blook 4 78.9 1.70 Block 8 89.3 3.30

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7 Page t 0 poV Although the voltage drops exceed the recommendations of R latory Culde 1.s, no 1 problems are antlolpated due to their minimal duration and t ability of the 450 V l E8MCC AC motor startere to remain energleed to The i totalload connected at the and of Block 5 is (188 EVA. Assuming a . power actor, this translatas to a $350 KW load whleh le 1.8% over the $300 KW thirty minute rattnr of the diesel generator. As allloads have been usumed at thalt nameplate rating. 0/C, Ino, feels there is suffielent conservatism in the load total to allow for the minimal overrun of the thirty minute rating until a permanent fix can be made. Also, alarms are provided in the control room to alert the operatora of diesel generator operation in excess of the 3000 EW continuous rating.

The E8 8 bus was not speelfles!!y reviewed as it was considered to be a less limiting caso due to the absence of the emergency feedwater pump and the artreme untlkollhood of the simultaneous operation of CHME 1B and CHHE-5. However, should both ehlliers be required to atart on Block 1, the voltage profiles of Blocks 1, 2, 3, and 4 will be slightly lower than those presented for Bus A. This le acceptable based on sim!!ar logio described above. It should be noted due to the lack of the emergency feedwater pump load on the IB 1B bus, the thirty minute rating of the diesel generator will not be exceeded.

Questions #2 We have reviewed the system effects of DCP 1A or DCP-1B starting on Binek 1, rather than Block 4 as designed, with the CR=3 Project Mechanleal Engineer Mr. T. C. Lutz, and have concluded there are no adverse effects to system performance due to this situation.

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l C/C, Inc. does not feel plant safety is compromised due to th!s situation, it is our l engineering judgement that the diesel generators should rema!n operable while providing ,

an adequate power profile to start and maintala the required loada.  ;

Quasilon #4 Although corrective action is recommended, it is not cor.sidered necessary to provide it immediately as no safety concern is created with the existing situations.

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Pete 3 Attached to th!s letter la the supporting calculations as well as its design input for thla review.

This completes C/C, Inc.'s response to the referenced memorandum and it is hoped this fulfills your needs. Howevers should you have any questions or require any further Information, please advise.

Very truly yours,

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,V R. P. Cronk reelect zieotrieelingineer I i R ha kProject Manager RPC/REV/kk Attachment ce: M. Del Castillo (2)

M. U. Rahman O. W. Castleberry J.H. Lander R. E. Vaughn (2)

T. C. Luts A. E. Azevedo (2) l