3F0993-04, Forwards Response to 5 of 6 RAIs in NRC Re Floor Response Spectra for Resolution of USI A-46.Floor Response Spectra for Upper Two Floors in Reactor Bldg in Process of Development & Will Be Provided by 931015

Forwards Response to 5 of 6 RAIs in NRC Re Floor Response Spectra for Resolution of USI A-46.Floor Response Spectra for Upper Two Floors in Reactor Bldg in Process of Development & Will Be Provided by 931015

ML20057A669
Person / Time
Site:	Crystal River
Issue date:	09/07/1993
From:	Beard P FLORIDA POWER CORP.
To:	NRC OFFICE OF INFORMATION RESOURCES MANAGEMENT (IRM)
Shared Package
ML19310E789	List: 3F0993-04, Forwards Response to 5 of 6 RAIs in NRC Re Floor Response Spectra for Resolution of USI A-46.Floor Response Spectra for Upper Two Floors in Reactor Bldg in Process of Development & Will Be Provided by 931015
References
REF-GTECI-A-46, REF-GTECI-SC, TASK-A-46, TASK-OR 3F0993-04, 3F993-4, TAC-M69440, NUDOCS 9309150124
Download: ML20057A669 (4)

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Power C0RPORATaON Crystal River Unit 3  ;

l Docket No. 50-302 '

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i September 7, 1993  !

3F0993-04 j i

U. S. Nuclear Regulatory Commission l Attn: Document Control Desk  :

Washington, DC 20555 '

Subject:

Request for Additional Information on Floor Response Spectra for the ,

Resolution of USI A-46 (TAC No. M69440)  :

References:

NRC to FPC letter dated July 9, 1993 (3N0793-07)

Dear Sir:

i The reference letter included 6 requests for additional information regarding the  !

floor response spectra to be used for resolution of Unre olved Safety Issue (USI)

A-46, Seismic Qualification of Equipment in Operating Nuclear Power Plants, for ,

Crystal River 3 (CR-3). The enclosure to this letter provides Florida Power  !

Corporation's (FPC's) response for 5 of those-6 requests. . The floor response  !

spectra for the upper two floors in the Reactor Building (Item.5) are in the  !

process of development and will be provided by October 15, 1993.

l Sincerely, 'I P. M. eard, Jr. S-l Senior Vice President Nuclear Operations j

PMB/AEF: l l ENCLOSURE Nh ,

xc: Regional Administrator, Region 11 NRR Project Manager Senior Resident Inspector ' L (* [

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GENERAL OFFICE: 3201 Thirts-fourth' street So'uth .

• P.O. Box 14042

• St. Petersburg, Florld's 33733 *' (813) 866-5151-9309160124 930907 A Florida Progress Company PDR ADOCK 05000302 M{@

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ENCLOSURE TO 3F0993-04 RESPCNSE TO NRC REQUEST FOR ADDITIONAL INFORMATION ON THE DEVELOPMENT OF FLOOR SPECTRA TO BE USED FOR RESOLUTION OF USI A-46 j FOR CRYSTAL RIVER 3  ;

Reference:

Attachment A of Florida Power Corporation's (FPC's) submittal to NRC  !

l dated April 16, 1993 j 1

. Reauest 1 )

i Provide a copy of Reference I cited in the above reference. I Response 1 Attachment 1 of this enclosure is a copy of Reference 1.

Reauest 2 Reference 9 has been cited as being used for the detailed description of the procedure, but has not been named or titled in the above reference. Provide a copy of Reference 9.  !

Response 2 l As shown by Attachment 2, this is the same document requested above.  !

Reauest 3 In Section 5.4.5 of the plant's FSAR, it is stated that the floor response spectra (FRS) are generated by time-history (TH) method and response spectrum (RS) method, and the FRS generated by the RS method were found to be enveloping those generated by the TH method. The staff assumes that the enveloping FRS will be used for the resolution of USI A-46 If the planned approach is different from the above assumption, provide information on the planned approach.

e Le_soonse 3 The NRC Staff's assumption that the enveloping FRS generated by the response spectrum method will be used for the resolution of USI A-46 is correct.

Reauest 4 From the information provided in the above reference, it appears that equations  ;

11 and 12 will be (or have been) used to interpolate the FRS for in-between i damping values; they will not be used for developing FRS by extrapolation. l Provide the actual procedure used.

Response 4 Based on the existing 0.5% and 1.0% damped floor response spectrum curves, the i Power method is used to generate the 5.0% damped floor response spectrum curve l by extrapolation. The accuracy of this method has been est ablished by I Gilbert / Commonwealth, Inc. on various past projects.

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. i ENCLOSURE TO 3FCu 3-04 by extrapolation. The accuracy of this method has been established by Gilbert / Commonwealth, Inc. on various past projects. j i

Reauest 5 l Provide horizontal floor response spectra for the two upper floors in the Reactor  !

Building. j Response 5 l The horizontal floor response spectra for the two upper floors in the Reactor Building are in the process of development. They will be submitted to the NRC j by October 15, 1993.

Reauest 6 l

l In Section 5.4.5.2 of the FSAR (Rev.14), it is stated that the vertical seismic  ;

input is not amplified by the walls and floors, through which the vertical motion j could be transmitted, if their frequencies are computed to be more than 25 cps. .

Provide information on the actual frequencies of walls and floors in the Seismic '

Category I structures. Provide information on the approach taken to incorporate

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l the vertical component of earthquake in verifying the adequacy of equipment and anchorages.

Response 6 ,

The vertical frequencies of the representative walls and slabs in the Auxiliary, I Intermediate, Control, and Reactor Buildings are documented in Gilbert / '

Commonwealth's Calculation No. 5011-076.1. This frequency study was performed in the early part of 1982 to address Emergency Feedwater System seismic  !

qualification concerns. A copy of this calculation is provided as Attachment 3 l of this enclosure.

i In verifying the seismic adequacy of equipment and anchorages,. the vertical  ;

earthquake component will be considered by scaling down the horizontal response  ;

spectrum for the respective floor elevation by two thirds.  ;

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4 ATTACHMENT 1 TO ENCLOSURE TO LETTER 3F0993-04  !

Seismic Analysis of Equipment Mounted on a Massive Structure (Reference 1 of attachment to FPC submittal dated April 16,1993) l l

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