ML17346A252

Forwards Addl Info Re 54-inch & 48-inch Containment Purge Valves,Per 840112 Request.Stress Levels for Closing Valves from Blocked Position Provided in Henry Pratt Stress Repts Dtd 820818 & 20,per Util 820917 Ltr

ML17346A252
Person / Time
Site:	Turkey Point
Issue date:	04/02/1984
From:	Williams J FLORIDA POWER & LIGHT CO.
To:	Varga S Office of Nuclear Reactor Regulation
References
L-84-86, NUDOCS 8404050296
Download: ML17346A252 (8)

Text

REGULATOR+NFORMATION DISTRIBUTION S'EM (RIDE)

ACCESSI'QN NBR:8404'050296 DOCBDATE: 84/04/02 NOTARIZED: NO DOCKET FACIL:50-250 Turkey Point PlantE Unit 3i Florida Power and Light C 05000250 50-251 Turkey Point Plant< Unit 4i Florida Power and Light C 05000251 AUTH'AME AUTHOR AFFILIATION HILLIAMSEJ.N ~ Florida Power 8 Light Co.

RECIP ~ NAMF- RECIPIENT AFFILIATION VARGApS ~ Ar Operating Reactors Branch 1

SUBJECT:

Forwards addi info r e 54-inch 8, 48-inch containment purge val.'vesEper 840112 request ~ Stress levels for closing valves from blocked position provideed in Henry Pratt stress repts d8d 820818 K 20Eper util 820917 ltr, DISTRIBUTION CODE: A034S COPIES RECEIVED:LTR ENCL 'IZEs TITLE: OR Submittal: Containment Pur ging NOTES:

RECIPIENT COPIES RECIPIENT COPIES ID CODE/NAME LTTR ENCL ID CODE/NAME LTTR ENCL NRR OR 0 1 BC 01 7 7 INTFRNAL'RR FIELDS' 12 1 1 NRR REEVESEE 14 1 EGB 09 1 1 NRR/DS I/AEB 1 1 G F 04 1 RGN2 1 1 EXTERNAL: ACRS 13 6 6 LPDR 03'5 1 1 NRC PDR 02 1 1 NSIC 1 1 NTIS 1 TOTAL. NUMBER OF COPIES REQUIRED: LTTR 23 ENCL 23

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FLORIDA POWER 8( LIGHT COMPANY April 2, 1984 L-84-86 OFSice of Nuclear Reactor Regulation Atte6tion: Mr. Steven A. Vargo, Chief Operating Reactor Branch // I Division of Licensing U.-'5. 'Regulatory Commission Wash'ington, D.C. 20555

Dear 'Mr. Varga:

Re: .'Turkey Point Units 3 8 4

'.Docket Nos. 50-250 8 50-25 I

,Vent/Pur e Valve 0 erabilit By .your letter dated January I 2, I 984, you requested the following addit ional information on the Turkey Point 54" and 48" containment purge valves:

I. Evidence that the dynamic torque coefficients (CTS) used to determine the

~ dynamic torques (TD) based on the worst case valve configuration apply to the

'"iHenry Pratt Model RA 48 and 54 inch valves; 2.:Information which demonstrates that the stress levels in all valve parts

.considered are within the design stress allowables when the valves are operated

'from the blocked positions; and,

3. '<nformation which shows that conservative safety factors were applied to CT

~,(straight pipe) valves when used to predict TD's in an RA valve that included an

.elbow in the piping configuration.

In response to this request, the following information is provided:

I. The Turkey Point RIA valves contain symmetric discs. Model testing on this

,style disc was performed using straight pipe. FPL letter, L-83-I20, dated March 4, l983, transmitted Henry Pratt's RIA valve stress reports (Rev.l) dated september I5, l98I and September I8, l98l. Pages 3 and 5 of these reports

show that worst case valve configurations were considered.

'1he torques provided in the September l98I reports provide an effective safety

factor on straight pipe model CT's of greater thon I.5. The inboard containment purge valves are installed "inplane" with regard to the upstream elbows;

'therefore, the CT used in this analysis is adequate with respect to the constraints expressed in your January l2, I 984 letter. The outboard containment

pvrge valves are separated from the inside volve by approximately IO feet of

'straight pipe which would tend to stabilize flow conditions. Consequently, the

'.'CT values used are appropriate for the Turkey Point Units 3 8 4 installation.

.840405029h 840402 PDR ADOCK 05000250 P PDR PEOPLE... SERVING PEOPLE

Page 2 Office. of Nuclear Reactor Regulation Mr. Steven A. Varga, Chief

2. The stress level information referenced in your January 12, 1984 letter was for closing the valves from a fully open position. Stress levels for closing the 54 and 48 inch valves from a blocked position were provided Henry Pratt's stress reports dated August 18, 1982 and August 20,

'n 1982. These reports were forwarded to you by FPL letter L-82-407, dated September 17, 1982. These reports show that only the 54 inch valve operator bolt stresses were greater than allowable. The calculated com-bined stress in the operator bolts was 22,708 pounds per square inch.

The allowable stress for this material is 22,200 pounds per square inch.

These reports also show that the 54 inch valve trunnion bolt stresses are near the allowable. Since the stresses on the operator and trunnion bolts exceed or approach the allowables, these bolts will be replaced as proposed in the August 1982 Henry Pratt reports. We have these bolts on order, and plan on installing them in the next refueling outage for Units 3 and 4.

Please find attached a justification for interim operation of these valves until the bolts can be replaced.

3. Response to this question i's covered in Item No. I above.

If you have any further questions, please contact us.

Very truly yours, J.W. Williams, Jr.

Vice President Nuclear Energy JWW/DJF/SAV/cas Attachments cc: J.P. O'Reilly, Region II (w/att.)

Harold F. Reis, Esquire

TURKEY POINT UNITS 3 8 4 CONTAINMENTPURGE VALVES JUSTIFICATION FOR INTERIM OPERATION The 54 inch containment purge volves can continue to be used until the replacement operator bolts are received and installed for the following reasons:

I. The bolt allowable stress reported by Pratt is below that given in Table 5A-I of the FSAR which shows the allowable equal to the yield strength. The yield strength for the bolts is much higher than the Pratt reported stress.

2. The loading conditions used in the Pratt analysis exceed those in the FSAR. The earthquake and LOCA loads are not combined in the FSAR to determine component stresses; however, the Pratt analysis considers these combined loads.

3. The purge valves are not required by the FSAR to meet ASME Section III requirements (particularly on stress allowables) because the original valve was purchased before nuclear valve requirements existed.

4". As stated in the FSAR: "On the basis of historical or statistical seismic activity, Turkey Point is. located in a seismically inactive areo, far from any recorded damaging shocks. Even though several of the lorger historical earthquakes may hove been felt in southern Florida, the amount of ground motion caused by them was not great enough to cause damage to any moderately well built structure.

The Uniform Building Code (1964 edition, Volume I, as approved by the International Conference of Building Officials) designates the area as Zone 0 on the map entitled Ma of the United States Showin Zones of A roximatel E ual Seismic Probabilit ." The stress. calculations for the 54" valve assume worst case conditions in that a LOCA and earthquake are postulated to occur simultaneously during containment purge operations. Since purge time is limited and the probability of either an earthquake or a LOCA is small, FPL believes that interim operation of the purge system is justified pending bolt replacement.

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