ML17352A479

Forwards Addl Info Re PORV & Block Valve Ts,In Response to NRC Request Concerning Util 921125 Proposed License Amends to Revise TS 3/4.4.4,3/4.4.9.3 & Associated Bases Sections, Per GL 90-06

ML17352A479
Person / Time
Site:	Turkey Point
Issue date:	03/04/1994
From:	Plunkett T FLORIDA POWER & LIGHT CO.
To:	NRC OFFICE OF INFORMATION RESOURCES MANAGEMENT (IRM)
References
GL-90-06, GL-90-6, L-94-054, L-94-54, TAC-M77389, TAC-M77390, TAC-M77464, TAC-M77465, NUDOCS 9403180112
Download: ML17352A479 (8)

Text

ACCELERATED DISTRIBUTION DEMONSTRATION SYSTEM 6

REGULATORY INFORMATION DISTRIBUTION SYSTEM (RIDS)

ACCESSION NBR:9403180112 DOC.DATE: 94/03/04 NOTARIZED: NO DOCKET FACIL:50-250 Turkey Point Plant, Unit 3, Florida Power and Light C 05000250

'0-251 Turkey Point Plant, Unit 4, Florida Power and Light C 05000251 AUTH. NAME AUTHOR AFFILIATION PLUNKETT,T.F. Florida Power 6 Light Co.

RECIP.NAME RECIPIENT AFFILIATION Document Control Branch (Document Control Desk)

SUBJECT:

Forwards addi info re PORV 6 block valve TS,in response to NRC rec{uest concerning util 921125 proposed license amends D to revise TS 3/4.4.4,3/4.4.9.3 6 assoc'.ated bases sections, per GL 90-06.

DISTRIBUTION CODE: A019D COPIES RECEIVED:LTR ENCL SIZE:

TITLE: Generic Ltr. 90-06 Resolution of GE PORV s & Block Relia z sty NOTES A RECIPIENT COPIES RECIPIENT COPIES D ID CODE/NAME LTTR ENCL ID CODE/NAME LTTR ENCL PD2-2 LA 1 1 PD2-2 PD 1 1 D CROTEAU,R 1 1 INTERNAL: NRR/DSSA/SRXB NRR/PDIV-2 1

1 1

1 G

/ $3J 01 1

1 1

1 RES/DSIR/EIB 1 '

R SIR/RPSIB 1 1 RES/EIB 1 1 EXTERNAL: NRC PDR 1 1 NUDOCS-ABSTRACT 1 1 D

D D

NOTE TO ALL "RIDS" RECIPIENTS:

PLEASE HELP US TO REDUCE WASTE! CONTACT THE DOCUMENT CONTROL DESK, ROOM Pl-37 (EXT. 20079) TO ELIMINATEYOUR NAME FROM DISCI'RIBUTION LISTS FOR DOCUMENTS YOU DON'T NEED!

TOTAL NUMBER OF COPIES REQUIRED: LTTR 12 ENCL 12

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APL MAR 04 1994 L-94-054 10 CFR 50.90 U. S. Nuclear Regulatory Commission Attn: Document Control Desk Washington, D.C. 20555

Subject:

Turkey Point Units 3 and 4 Docket Nos 50-250 and 50-251

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Proposed License Amendments Additional Information Generic Letter 90-06 TAC Nos. M77464 M77465 M77389 and M77390 By letter L-92-285, dated November 25, 1992, Florida Power 6 Valves'Company (FPL) submitted proposed license amendments to Light 3/4.4 ',

revise the Turkey Point Units 3 and 4 Technical Specifications "Relief Valves," 3/4.4.9.3, "Overpressure Mitigating Systems," and the associated Bases sections 3/4.4.4, "Relief

" The purpose of this letter is to provide in the attachment additional information as requested by members of the NRC staff.

If you contact us.

have any questions regarding this information, please Very truly yours T. F. Plunkett Vice President Turkey Point Plant Attachment TFP/OIH cc: Stewart D. Ebneter, Regional Administrator, Region II, USNRC T. PE Johnson, Senior Resident Inspector, USNRC, Turkey Point Plant

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PDR ADOCK 05000250

.P PDR an FPL Group company

n Atta'chment to L-94-54 Page 1 of 3 Information Regarding PORV and Block Valve Technical S ecifications As a result of FPL's submittal of November 25, 1992 (Reference 2), the NRC staff has identified some additional information that is required to clarify FPL's position related to the Power Operated Relief Valve and Block valve Technical Specifications submitted in response to Generic Letter 90-06 (Reference 3) . The two areas identified by the staff relate to the reliability of the emergency feedwater supplies at Turkey Point and the design aspects of the Pressurizer Auxiliary Spray valve at Turkey Point.

Reliabilit of Emer enc Feedwater The Turkey Point plant is capable of providing feedwater to the steam generators from three separate sources:

1. The main feedwater pumps,

2. the auxiliary feedwater pumps, or

3. the Standby Steam Generator Feedwater Pumps (SSGFP)

The main feedwater pumps require the availability of offsite power and the operation of the condenser and condensate system for operation. This is the normal feedwater supply during plant operation.

The auxiliary feedwater (AFW) system at Turkey Point consists of three steam driven auxiliary feedwater pumps, each of which is capable of providing 100% of the emergency feedwater requirements for both nuclear units. Water for the AFW pumps is provided by two condensate storage tanks, one for each unit. Steam may be supplied to the AFW pump turbines from either unit The AFW pump

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turbines are vented directly to atmosphere and are thus not impacted by the availability of the plant condenser. The AFW system is designed to safety-related requirements and is capable of operation with no on-site AC power available (Reference 1).

To augment the AFW system at Turkey Point, a Standby Steam Generator Feedwater system was installed in the early 1980s. The standby feedwater system consists in part of two electric driven feedwater pumps, each of which is capable of providing 100% of the emergency feedwater needs to both units. Water for the standby pumps is provided by a separate demineralized water storage tank. This system is not safety-related and is powered electrically from a separate non-vital 4.16 kV electrical bus (i.e. the "C" bus) The "C" bus is presently capable of being

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powered from the non safety-related blackstart diesel generators at Turkey Point. FPL has submitted a Proposed License Amendment

Atta'chment to L-94-54 Page 2 of 3 (PLA) to eliminate reliance on the blackstart diesel generators.

In this case, one of the SSGFPs will be powered from offsite power using the "C" bus and the remaining SSGFP will be directly powered with its own non-safety diesel (Reference 4) . Subject to NRC approval, this design modification is expected to be implemented in 1995.

As described above, the Turkey Point plant has a 500% capacity emergency feedwater system that is comprised of both the safety-related AFW system and the non safety-related standby feedwater system. More recently designed plants are provided with two electric driven and one steam driven auxiliary feedwater pumps, for a total emergency feedwater capacity of 300%. Failures associated with this later design are dominated by instances where the steam driven pump is taken out of service for maintenance and a challenge occurs to the plant with a concurrent common mode failure of the electric driven AFW pumps. These failure sequences are not applicable to Turkey Point due to the fact that during any anticipated maintenance evolution, there would always be diverse (i.e electric and steam driven) sources

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of feedwater available to the plant. This significantly reduces the likelihood of a total loss of feedwater event at Turkey Point.

Auxiliar S ra Valve Desi n The auxiliary spray valve is a fail closed air-operated valve.

The solenoids used to operate this valve are powered from vital DC power supplies. The power supply design incorporates a transfer switch to permit valve operation from outside the control room in the event of a control room evacuation.

Air to operate the auxiliary spray valve is supplied by the instrument air system. Instrument air for each unit is provided by redundant diesel driven air compressors that do not require the availability of either on-site or offsite AC power.

The design incorporates the use of vital DC power and AC independent instrument air to provide a highly reliable design.

Atta'chment to L-94-54 Page 3 of' References Turkey Point Updated Final Safety Analysis Report, Rev. 11, November 1993.

2. FPL letter L-92-285, "Proposed License Amendments Response to Generic Letter 90-06 Resolution of Generic Issues 70 and 94," dated November 25, 1992 Generic Letter 90-06, "Resolution of Generic Issue 70,

'Power-Operated Valve and Block Valve Reliability,'nd Generic Issue 94, 'Additional Low-Temperature Overpressure Protection" for Light-Water Reactors,'ursuant to 10 CFR 50.54(f), dated June 25, 1990.

4. FPL letter L-93-200A, "Proposed License Amendments Elimination of Cranking Diesel Generators," dated September 3, 1993.

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