ML17338A757

Provides Addl Info Re Costs of Limiting Containment Purges During High Power Operations.Util Attempting to Resolve Issues Raised in NRC 781128 Ltr.Combined Containment Purges in Interim to Be Limited to 200-h/year

ML17338A757
Person / Time
Site:	Turkey Point
Issue date:	06/08/1979
From:	Robert E. Uhrig FLORIDA POWER & LIGHT CO.
To:	Schwencer A Office of Nuclear Reactor Regulation
References
L-79-158, NUDOCS 7906130235
Download: ML17338A757 (6)

Text

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ACCESSION NBR:79061302'35 DOC",'DATES 79/06/08 NOTARIZED:'O Point -Planti Unit 3g Florida Power and Light" C'5000250 DOCKET.'.0'ACIL:50 250 Turkey 50 251 Turkey Point" F'lant'Unit= 4i, Florida Power and Light>> C 05000251>>

AUTH INANE. AUTHOR AFFILIATION UHRIGiR,ED Florida- Power L Light Co, RECIPBNAME" RECIPIENT AFFILIATION SCHHENCERiA, L.ight 81aterI Reactors Branch SUBJECT; Provides addi info re costs of limiting.'containment purges during high power operations;Util attempting to rosolye issues raised in NRC 781128 ltrCombined containment~ purges>>

in interim to be. limited to 200.-h per year, DISTRIBUTION CODE! A034S'OPIES RECEIVED:LTR 9 ENCL SIZE!

TITLE! Containment Pur ging, II A tl t! It $ II I $ II $ '>> ll ) ~

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RECIPIENT COPIES "RECIPIENT" 'COPIES ID'ODE/NAME" t-TTR ENCL." ID CODE/NAME. LTTR" ENCL' ACTION!: 05 BC<)~ ( '7 INTERNAL! 0 REG 1 02'RC PDR 1 1 2 14 TA/EDO- 1 15 COREI PERF BR 16'D SYS/PROJ 17 ENGR BR 1 18 REAC SFTY "

• SR 1 19 PLANT SYS BR 1 20 EEB 1 21 EFLT TRT- SY8 1 22'RINKMAN 23 C'RIMES 24.,EI REEVES 1 EXTERNAL: 03 LPDR 04 NSIC 1 1 25 ACRS 16 1 0

TOTALS NUMBER OF COPIES REQUIRED'TTR 40 ENCL

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BOX 013100, MIAMI, FL 33101 gyes I/g Wrr. aa FLORIDA POWER & LIGHT COMPANY June 8, 1979 L-79-158 Office of Nuclear Reactor Regulation Attention: Mr. A. Schwencer, Chief Operating Reactors Branch Ioil Division of Operating Reactors U. S. Nuclear Regulatory Commission Washington, D.C. 20555

Dear Mr. Schwencer:

Re: Turkey Point Units 3 and 4 Docket Nos. 50-250 and,"50-'251 Containment Pur'in II If Your letter of November 28, 1978 provided guidance concerning containment purging during normal operation. In our letter to you of February 1, 1979, we indicated that we planned to justify unlimited purging, and that we would continue our practice of minimizing purges. Our letter went on to say that an excessive restriction on containment purges would have a negative effect on the working environment in the containment.

The purpose of this letter is to provide additional information regarding the costs associated with limiting containment purges. This letter also provides more information-on our plans for final resolution of this issue.

Since the potential consequences of a postulated -loss of coolant accident (LOCA) are mitigated at low power level and shutdown conditions, we have con-centrated on limiting containment purges during high power operations.

The containment purge history for calendar year 1978 for Turkey Point Units 3 and 4 was:

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'>, 2/ Power > 200 F < 200 F 225 Hours 722 Hours 2260 Hours We have reviewed the purge history for Turkey Points Units 3 and 4, and based on this review we have concluded that elimiBation of containment purges with primary system temperature greater than 200 F would result in an estimated eight additional days of shutdown time per unit per yea~. A limitation of con-tainment purges to 90 hours0.00104 days <br />0.025 hours <br />1.488095e-4 weeks <br />3.4245e-5 months <br /> per unit per year above 200 F would result in an estimated 4-5 days additional shutdown time, while a limitation of 90 hours0.00104 days <br />0.025 hours <br />1.488095e-4 weeks <br />3.4245e-5 months <br /> per unit per year at power would result in an estimated 1-2 days of shutdown time.

Estimated down time is largely a function of the maintenance activity to be per-formed. The above estimates assume certain maintenance activities can be per-formed at temperature and at power without a purge of containment. However, some maintenance can only be performed at temperature with a purge. .Should .,

the frequency of such maintenance be greater than our predictions, which are

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Office of Nuclear Reactor Regulation Attn: Mr. A. Schwencer, Chief Operating Reactors Branch tl Page 2 based on 1978 experience, then the outage time could be significantly increased.

A single shutdown and cooldown to deal with a problem which would otherwise be corrected at power, would add at least one additional day of lost generation time. Fossil fuel used to generate replacement electricity while Turkey Point is off-line costs $ 300,000 - $ 400,000 a day.

The containment entries made at power without containment purges would require that our personnel'work in exceedingly high temperatures and humidity. Since these working conditions also reduce productivity,,more time and more personnel would. be required for each job. A higher man-rem total for each job would re-sult. We estimate this increase, in man-rem to be on the order of two to three times that associated with a purge. This is due primarily to the increased time and people involved. Total man-rem would also increase significantly .in the event that we develop a higher percentage of fai>led fuel than "we are currently experiencing. Another consequence of. reduced purge time would be. a loss of flexibility to handle problems which might develop during operation.

We are pursuing several alternatives for final resolution. of the issues raised in your letter of November 28, 1978., We will be meeting with the valve manufac-turer this week, along with our consultants, to further evaluate resolution of this issue. In addition, we are analyzing the effect of valve closure time on ECCS performance, and radiological consequences. We plan-to have these analyses completed by October 1, 1979.

Until our analyses and any necessary plant modifications have been completed, we will limit our combined containment purges-for Turkey Point Units 3 and 4 during power operation (>2K power) to 200 hours0.00231 days <br />0.0556 hours <br />3.306878e-4 weeks <br />7.61e-5 months <br /> per year for the site (200 hours0.00231 days <br />0.0556 hours <br />3.306878e-4 weeks <br />7.61e-5 months <br /> total for both units.)., I'. order to allow promulgation of the appropriate instructions to our employees, and to be consistent with other record keeping requirements, this requirement will be implemented beginning July 1, 1979.

We will keep you informed of our progress in, this matter. Please feel free to contact me if you should have any question.

Very truly yours, Robert E. Uhrig Vice President Advanced Systems 5 Technology REU:GDW:cf cc: James P. O'.Reilly, Region II Robert Lowenstein, Esquire

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