ML17341B496

Proposed Tech Spec Changes,Modifying Flowrate of Auxiliary Feedwater Sys from 600 Gpm to 373 Gpm for Model 44F Steam Generators.Safety Evaluation Encl

ML17341B496
Person / Time
Site:	Turkey Point
Issue date:	11/05/1982
From:	FLORIDA POWER & LIGHT CO.
To:
Shared Package
ML17341B495	List: ML17341B494 ML17341B496
References
NUDOCS 8211160275
Download: ML17341B496 (22)

Text

4. 10 AUXILlARY FEEDWATER SYSTEN P

feedwater system.

Objective: To verify the operability, of the auxiliary feedwater system and its ability to respond properly when required.

1. Each turbine-driven auxiliary feedwater pump shall be started at intervals not greater than one month, run for 15 minutes and a flow rate of 373* 'gpm established to the steam generators. The monthly frequency is not intended to require the test while at cold shutdown. The testing requirement is met by performing this test during startup subsequent to cold shtudown.

2. The auxiliary feedwater discharge valves shall be tested by operator action during pump tests.

3. Steam supply and turbine pressure valves shall be tested during pump tests.

4. These tests shall be considered satisfactory if control panel i ndication and visual observation of the equipment demonstrate that all components have operated properly.

~5. At least once per 18 months:

a. Verify. that each automatic val-ve in the fl.ow path actuates to its correct position upon receipt of each auxiliary feedwater actuation test signal.

b. Ver'ify that each auxiliary feedwater pump receives a start signal as designed automatically upon receipt of each axuli ary feedwater actuation test signal.

N.A. during col'd or refueling shutdowns (only for the Unit at cold or refueling shutdown). The specified tests, however shall be performed within one surveillance interval prior to starting the turbine.

8211'160275 821105 ' jj PDR'DOCK 05000250 j P ,PDR

• 600'pm flow rate remains applicable to Turkey Point Unit 4 until steam generator replacement.'."10-1 11/05/82

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83.8 BASES. FOR LIMITING CONDITIONS FOR OPERATION, STEAN AND POWER CONVERSION SYSTEMS In the unlikely event of complete loss of electrical power to the nuclear units., decay heat removal will be assured by the availability of the steam-driven auxiliary feedwater pumps and steam discharge to the atmosphere via the steam generator safety valves and power relief valves.(l) The operability of the auxiliary feedwater system ensures that the Reactor Coolant System can be cooled down to less than 350'F from normal operating conditions in the event of a total loss of offsite power. Each steam driven auxiliary, feedwater pump is capable of delivering a total feedwater flow of 373* gpm to the entrance of the steam generators. This 'capacity is sufficient to ensure that adequate feedwater flow is available to remove decay heat and'educe the Reactor Coolant System temperature to less than 350'F when the Residual Heat Removal System may be placed into operation. The minimum amount, of water in .the condensate storage tanks is established from FSAR Figure '9. 11-1, and meets safe shutdown requirements. (2)

The limit on secondary coolant iodine-131 specific activity is based on a postulated release of secondary coolant equivalent to the contents of three steam generators to the atmosphere due to a net load rejection. The limiting dose for this case would result from radioactive iodine in the secondary coolant. I-131 is. the dominant isotope because of its low HPC in air and because the other shorter lived iodine isotopes cannot build up to significant concentrations in the secondary coolant under the limits of primary system leak rate and activity. One tenth of the iodine in the secondary coolant is assumed to reach the site boundary making allowance for plate-out and retention in water droplets. The inhalation thyroid dosei at the site boundary is then;

.Dose (Rem) C

' ' 'CF '/Q 0.1 Where: C secondary coo)ant I-131 specific activity, 1.34 curies/m (uCi/cc) or 0.67 Ci/m, each unit V equivalent secondary.ccolan) volume released = .214 m B breathi ng rate = 3. 47 x 10 m sec.

X/Q atmospheric dispersion parameter =1.54 x 10 sec/m 0.1 equivalent fraction of'ctivity released DCF dose conversion. factor, Rem/ci The resultant thyroid dose is less than 1.5 Rem.

Refer ences (1) FSAR - Section 10.3 (2) FSAR - Section 14.2.5

• 600 gpm flow rate remains applicable to Turkey Point Unit 4 until steam-generator replacement.

B3.8-1 11/05/82

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SAFETY EVALUATION Re: Turkey Point Units 3 5 4 Docket Nos. 50-250 and 50-251 Proposed Techni ca 1 -Speci fi'cat i on Change Auxiliary Feedwater Flow Re uirements Ref: (a) Westinghouse letter G.J. Murray to C.O. Woody, June 3, 1982 (attached)

(b) Westinghouse -letter G.J. Murray to C.O. Woody, July 15, 1982 (attached)

I. Introduction This evaluation supports a Technical Specification change for Turkey Point Units 3 and 4 to reduce the aux'iliary feedwater flow requirements from 600 gpm in 3 minutes to 373 gpm in 3 minutes. The proposed change to Technical Specification 4.10. 1 and 8 3.8 is to comply with recommendations made by Westinghouse (Ref. A) as described i n the following evaluation.

II. Evaluation Westinghouse Electric Corp. was requested to perform analyses to establish the minimum required auxiliary feedwater flow.

Westinghouse has completed the analyses and provided results via referenced (a). Reference (b) i ndicates that the analysis is also applicable for a power level of 2300 MWT. These r esul'ts indicate that the minimum required auxiliary feedwater flow to the steam generators is 373 gpm (based on .3 minute delay for initiation flow). Uur Power Plant Engineering Department's evaluation of the Westinghouse analyses follows:

1. The transient analyzed is loss of main feedwater. It was previously established that this transi ent was the limiting even't for sizing of the auxiliary feedwater pumps at Turkey Point. This is also consistent with FSAR Section 14. 1.11.

2. The acceptance criteria is to preclude filling of tne pressurizer.

This is identical to previous work and FSAR Section 14. 1. 11.

3. Initial power level was 2307.4 MWT plus an additional calorimetric error. Previous analyses (FSAR 14. 1. 11) were performed with an initial power level of 102$ of 2300 MWT. This i,ndicates that the minimum required auxiliary feedwater flow of 373 gpm is based on conservative power assumptions.

4. The computer code used was LOFTRAN. This code is of recent vintage and has been accepted by NRC in connection with transient analysis performed by Westinghouse.

4i Proposed Technical Specification Change Auxiliary Feedwater Flow Requirements Safety Evaluation Pa e Two

5. The analyses are applicable to a plant configuration using model 44 F steam generators.

It is our conclusion that the work performed by Westinghouse can oe used in support of an operating license amendment for Turkey Point Units 3 and 4 to reduce the auxiliary feedwater flow requirements from 600 gpm in 3 minutes to 373 gpm in 3 minutes."

III. Conclusion We have concluded, based on the referenced Westinghouse Analyses and our Power Plant Engineering Oepartment's evaluation as discussed above, that: (1) because this Technical Specification change does not involve a significant increase in the probability or consequences of accidents previously considered and does not involve a significant decrease in a safety margin, the change does not involve a significant hazard consideration; (2) there is reasonable assurance that the health and safety of the public will not be endangered by operation in this proposed manner; and (3) such activities will oe conducted in compliance with the Commision's regulations and the issuance of this amendment will not be inimical to the common defense and security or to the health and safety of the public.

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W-P P-62 7-fg 99 l~

Nu:lear Commercial Westinghouse YYater Reactor OOerarlons Division Electric Corporation Divisions Box 355

, PittsburghPennsylvanla15230 Mr. C. 0. Woody, Manager June 3, 1982 Power Resources, Nuclear Florida Power and Light Company Ref: JPT-82-048 P.O. Box 529100 P.O. 93000-85525 Miami, FL 33152 DWA 93421 GO MI-28460, CN 003

Dear Mr. Woody:

FLORIDA POWER AND LIGHT COMPANY TURKEY POINT UNITS 3 AND 4 Auxiliar Feedwater Flow Re uirements The attached Auxiliary Feedwater Analysis is provided in fulfillment of the requirements of the referenced order. Specifically, the Analysis addresses:

1. Minimum required auxiliary feedwater flow as a function of a 1 to 3 minute delay in startup for a loss of main feedwater event.

2.'inimum required auxiliary feedwater flow for a 3-minute delay in start-up under station blackout conditions.

The analyses are plant specific, applicable to 'Turkey Point Unit 3 and will also be applicable to Turkey Point Unit 4 after replacement of the steam generators.

These analyses were performed. according to accepted Westinghouse equality Assurance procedures>

Thank you for the opportunity to provide this engineering service. Should you have any questions or require any clarification on this transmittal, please con-tact the Westinghouse Project Office.

Very truly yours, WESTINGH USE LECTRIC CORPORATION GJM:rst G. . Murra Pro ect Engineer Attachment Florida Power 5 Li t Project cc: C. 0. Woody, 3L, 3A H. N. Paduano, 1L, lA R. J. Acosta, 1L, 1A H. E. Yaeger, 1L, 1A L. Whitney, lL, lA E. V. Rutledge, lL

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Attachment to W-PTP-62 AUXILIARY FEEDWATER FLOW REQUIREMENTS FLORIDA POWER 5 LIGHT TURKEY POINT UNITS 3 AHD 4 The requirements for auxiliary feedwater flow, which had been previously set when the original FSAR analyses were done, have been re-evaluated using up-to-date analytical methodology in an attempt to reduce those requirements.

The licensing basis for the Turkey point Units requires that auxiliary feedwater flow requirements for long-term heat removal be determined by evaluating the loss of main feedwatei transient to preclude pressurizer fill up. In support of this evaluation, Westinghouse was asked to determine the minimum required auxiliary feedwater flow to all three steam generators as a function of a start-up delay between 1 and 3 minutes for a loss of main feedwater event (more limiting than a station blackout due to the addition of pump heat). Additionally, a request was made for the minimum required auxiliary feedwater flow 'for a startup delay of 3 minutes for a station blackout event for informative purposes.

A loss of main feedwater/station blackout is initiated by a loss of feedwater flow to all steam generators. The level in the steam generator drops since the turbine still draws off steam and within one minute the level will have

. dropped to the lo-lo steam generator reactor trip setpoint which will initiate a reactor trip and an auxiliary feedwater system actuation signal. Because of the generation of decay heat and the turbine trip which follows a reactor trip, the secondary temperature increases until the steam generator safety valves are opened to become the heat sink for the plant. Primary temperature and pressurizer level will increase until the point .at which core decay heat and/or reactor coolant pump heat decreases to the auxiliary feedwater system heat removal capacity. The difference between the loss of main feedwater and station blackout transients is the addition of reactor coolant pump heat for the loss of main feedwater mandating higher minimum required auxiliary feedwater flow rates.

Plant specific loss of main feedwater/station blackout analyses were performed assuming the current plant configuration of 2208 hWT with model 44F SG's.

The assumptions used in these analyses are consistent with those used in current safety analysis methodology, including the use of the LOFTRAN computer code.

Table 1 is a detailed time sequence of the transient events for the cases analyzed.

Figur'es 1 and 2 are plots of the transient parameters of pressurizer pressure, pressurizer water volume, primary side temperature, and steam generator pressure for case 1 in Table l. All cases in Table 1 meet the applicable criteria of precluding pressurizer fill up and having adequate long-term heat removal for the given auxiliary feedwater flow. Figure 3 is the recommended'inimum required auxiliary feedwater flow as function of startup time based on those cases.

a depicted in Table 1 for the loss of main feedwater transient. For the case of station blackout, an analysis was done to determine, that for an auxiliary feedwater delay of 3 minutes, an auxiliary feedwater flow rate of 286 gpm to 3 steam generators's adequate to preclude the filling of the pressurizer.

The analysis was performed according to accepted Westinghouse Quality Assurance.

procedures. This is also to confirm that the analysis, is applicable to both Turkey Point Units 3 and 4 with replaced steam generators.

Pael of 5'

0 TABLE 1

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TINE SEQUENCE OF-EYENTS FOR LOSS 'OF HAIN FEEDHATER/STATION BLACKOUT ANALYSES PERFORMED AT THE EHGIHEERED SAFEGUARDS DESIGN POllER RATING Case 2 3 4,5.. "6 7 8 9*

Auxiliary Feedwater Flow (gpm) 356.0 357.0 361.0 366.0 373.0 420.0 473.0" 502.0 206.0 Auxiliary Feedwater System Actuation Time Delay (sec)

\

' I'20.0

..60.0 .: 90.0 150,0 180.0 340.0

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450,0

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500,0

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180.0 Event Time sec I t p

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• l1ain Feedwater Flow Stop '10.0 10.0 10.0 '0.0 10.0 10.0 10.0 10.0 10.0 Low-Low SG Hater Level Reactor Trip 66.1 66.1 66.1 66.1 66;1 '66.1 66,1 " 66.1  : 66.1 Rod.Begins to Drop 60.1 68.1 60.1 60.1 68.1 60.1 60,1 '60.1 68;1 SG Begins to Receive Auxiliary Feedwater 126.1 156,1 106.1 216.1 . 246.1 406.1 516.1 566.1. 246.1 Core Decay lleat and/or Pump I' P

~ I lleat Decrease to Auxiliary Feedwater lleat.Removal Capaci ty 2008. 0 2744. 0 2500. 0 2400. 0 2212. 0 1248. 0 '52.0 872. 0 2192. 0 Peak Pressurizer Hater Level Occurs 2040.0 .. 2740.0 2632.0.'504.0 2276.0'324.0 068.0 .. 904.0, 2312.0 I

• Sta tion Blackout

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2500

'2000

, 1500 I~~

1000

'000 1500 5

1000

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10 2 5 10 2 5 ']0 2 5 10, 2 5 10 Time (Sec)

FIGURE 1 PRESSURIZER PRESSURE AhD MATER YOLUYiE

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650 HOT LEG 600 COLD LEG 550 500 450 1500 1250 1000 4

750:

'.500

'50 10 2 5 10 2 5 10 2 5 10 2 5 10 Tim (Sec)

FIGURE 2 LOOP COLD ND. HOT TEMPERATURES AND STEAM GENERATOR PRESSURE

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A P'i) W-PTP-68 Westinghouse Water. Reactor truclear Commercial Operations Olvision Electric Corporation Divisions Box 355 Pit tsbvri.hPennsylvanla 15230 Mr. C. 0. Woody, Manager July 15, 1982 Nuclear Energy Florida Power 8 Light Company Ref: JPT-82-048 P.O. Box 529100 P.O. 93000-85525 Miami, FL 33152 DWA 93421 GO MI-28460, CH3

Dear Mr. Woody:

W-PTP-62 FLORIDA POWER 8t LIGHT COMPAHY TURKEY POINT UNITS 3 AHD 4 Auxiliar Feedwater Flow Re uirements In response to a question by Mr. Donis, of Florida Power 5, Light, on the Analysis transmitted by W-PTP-62, Westinghouse offers the following response:

Per normal analytical methodology for the loss of normal feedwater transient, Westinghouse used a power level corresponding to the engineered safeguards design rating (2307.4 MW ) in the subject analysis. An additional 2N calori-metric'rror was assumed. The 2208 MWt value was used in the report to.avoid confusion with 'uprating.

Should you have any additional questions on this report, please contact th Westinghouse Project Office.

Very truly yours, WESTINGHOUSE ELECTRIC CORPOPATIOH GJM:rst G.. Mu ray, r ject Engineer Florida Power ight Project cc: C. 0. Hoody, 1L H. H. Paduano, 1L R;.'J'; Acosta 1L,-,-, " -:

H. E. Yaeger, 1L J. Donis, 1L ~ ~

R. L. Whitney, 1L E. V. Rutledge, 1L J~~ 8 0 198z

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