ML20062E416

Final Deficiency Rept on Pipe Break Outside Containment.S&W Computer Prog Resulted in Nonconservative Temp Predictions. Corrective Action:New Computer Model & Environ Analysis of Temp Conditions.Equip Eval Is in Progress

ML20062E416
Person / Time
Site:	Shoreham File:Long Island Lighting Company icon.png
Issue date:	11/03/1978
From:	Novarro J LONG ISLAND LIGHTING CO.
To:	Grier B NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION I)
Shared Package
ML20062E414	List: ML20062E411 ML20062E416
References
SNRC-333, NUDOCS 7812070115
Download: ML20062E416 (4)

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/. FACO LONG ISLAND LIGHTING COMPANY

_ *,,','amm SHOREHAM NUCLEAR POWER STATION h 2. ,  %

P.O. SOX 618. NORTH COUNTRY ROAD e WADING RIVER. N.Y.11792 l

November 3, 1978 SNRC-333 l

) Mr. Boyce Grier, Director Office of Inspection & Enforcement i Region 1 U.S. Nuclear Regulatory Commission

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631 Park Avenue King of Prussia, PA 19404 1

1 j LONG ISLAND LIGHTING COMPANY Shoreham Nuclear Power Station - Unit 1 Docket No. 50-322 O

Dear Mr. Grier:

On March 22, 1978, in accordance with 10CFR50.55(e), we reported verbally to Region 1 a deficiency in our initial Pipe Break Out-side Containment (PBOC) report. On May 2,1978, we submitted an interim 30-day report on this deficiency. On July 27, 1978, we submitted an interim 90-day report giving further information on the subject deficiency. This letter will serve as our final written report.

Descriotion of Deficiency 4

i As previously reported the Stone & Webster computer program used to evaluate environmental effects of high energy pipe breaks had

,,s inherent in the program an assu=otion which oroved to be an over-V simolification of the thermal hydraulic effects and resulted in non-conservative temperature predictions.

j Corrective Action 1

Also as indicated in our orevious letters. Stone & Webster had undertaken a program to develop an imoroved computer model to i better relate thermodynamic relationships at the break to j

in-plant conditions. The n'e w model expanded the number of nodes in the vicinity of the pipe break and also incorporated additional

' features in the new model (i.e. active heat sinks, ventilation effects , free convection and phase separation for two-phase breaks) .

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j As indicated in our July 27, 1978, letter, the new comouter model a has been developed and now is being used to evaluate Shoreham specific temperature effects for all postulated pine breaks in-side secondary containment. Once the environmental effects of the F

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1 November 3, 1978 Mr. Boyce Grier c Page 2 l pipe break were known the evaluation of the Shoreham specific i

I safe shutdown equipment was to be evaluated to insure that the

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environmental qualifications for this equipment bounded the now predicted environmental effects of the pipe breaks. This analy-sis has now been completed and will be an integrated part of the

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revised submittal of the Shoreham Pipe Break Outside Containment

, ' q Report which appears as Appendix 3C of the Shoreham FSAR. This I

report will be submitted to Mr. H. Denton, Director, Office of

._ 1 Nuclear Reactor Regulation, in late November.

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Results of Environmental Analysis i

s As a result of the analysis performed in the high energy pipe l

1 break program, certain maximum temperatures and pressures were

! determined to be limiting for various locations in the reactor

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building. These conditions will be published in the PBOC report.

Where a specific temperature in an trea exceeded the equipment limits, additional investigations were made to determine the actual temperature at the equipment location due to the break or whether the temperature transient was sufficiently short so as to preclude equipment failure. A loss of function of a component is acceptable if an analysis can show that a redundant component or 1

backup system is available to perform the backup safety function and to insure safe reactor shutdown.

i Table 3C.3-lC, " Environmental Qualification of Electrical Equip-ment Required for Safe Shutdown", is attached and summarizes the present Shoreham specific qualification parameters for these type components.

- Eculpment Evaluation As stated above, the new analysis has generated the worst case

~ temperature conditions produced at general locations within the secondary containment of the reactor building. These conditions do not include temperatures at the immediate vicinity of the break.

i All equipment outside the immediate vicinity of the breaks has been evaluated and the environmental qualficiations are bounded by the

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November 3, 1978 Mr. Boyce Grier l 3

Page 3 analyzed temoerature conditions mentioned above. Still remaining is the specific evaluation of equipment in the immediate vicinity

, of the breaks where the temoeratures exceed the general qualifi-cation temperatures. We will either ensure that no equipment 4 needed for safe shutdown will be located in these zones, or, alternatively, protect any " safe shutdown" equipment from the 4

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pipe break effects.

Very truly yours, t  !

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J. P. Novarro Project Manager Shoreham Nuclear Power Station RMK:jv cc: Mr. John G. Davis, Director l Office of Inspection & Enforcere:!*.

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TABLE 3C.3-10 ENVIRONMINTAL QUALIFICATION OF ELICM ICAL EOUI? MENT

,, , , l REOUIRED FOR SAFE SEUTDOWN 4 Oualification(23'~

,d 3 Temp Press.

,, , Ecuiement (F) (Psia) Rumid.

Motors u,000 V 212 .14.95 Sat.

I 480 V 212 17.7 Sat.

] 125 V (de) 148 29.7 Sat.

i Motor operated

valves (ac) 212C*) 39.7 Sat i

1 valves (de) 212C*3 39.7 Sat.

p. Special valves (2) 340 39.7 Sat.

s Motor control

, center (3) 104 14.7 90% ,

Cable 340 54.7 Sat.

Electrical pene-trations 340 62.7 Sat.

, Remote shutdown l panel (3) 120 14.7 907.

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Instrumentation 212 15.7 Sat.

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l O) Each co=ponent is qualified to the indicated value for

) a minimum of one hour or to the anticipated conditions e

,- (Table 3C.2-9) at the component location.

l (2) Special falves include the RCIC valves in the main steam j

4 tunnel penetration area which may be required to operate

' for breaks in that area.

. % of most concern..

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MCCs and remote shutdown panel are protected from high j temperature and pressure effects (See Section 3C.3.4.0 4 I

(*) Qualification upgraded by inspection to 250 F as limited by the motor winding insulation. ,

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