ML20064K830

Forwards Eqe Rept 42103-R-001, Seismic Reanalysis of Reactor Bldg Pilgrim Nuclear Power Station & Stevenson & Associates Calculation C-002, Soil Properties for SSI Analysis for Pilgrim Site, in Response to GL 87-02,Suppl 1

ML20064K830
Person / Time
Site:	Pilgrim
Issue date:	02/09/1994
From:	Boulette E BOSTON EDISON CO.
To:	NRC OFFICE OF INFORMATION RESOURCES MANAGEMENT (IRM)
Shared Package
ML20064K833	List: ML20064K830 ML20064K834 ML20064K841
References
94-16, GL-87-02, GL-87-2, NUDOCS 9403230305
Download: ML20064K830 (5)

Text

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BOSTON EDISON ,

Pilgnm Nuclear Power Station Rocky Hill Road 50.54(f) *

. Plymouth, Massachusetts 02360 -

GL 87-02, Supp. 1 H ,

E. T. Boulette, PhD Senior Vice President-Nuclear BECo 94-16 February 9, 1994 10 U. S. Nuclear Regulatory Commission i Document Control Desk  :

Washington, DC 20555 l License DPR-35  ;

Docket 50-293 <

AMIT10NAL RESPONSE TO GENERIC LETTER 87-02, SUPPLEMENT 1 (TAC NO. M694H 1  :

P As requested in Generic Letter (Gt) 87-02 Supplement 1, Boston Edison previously submitted the Pilgrim design floor spectra for Staff review by letter dated 1

. . September 21, 1992. NRC's reply dated November 18, 1992, transmitted a. Safety '

Evaluation Report that concluded this spectra should be treated as " median centered

.. regionse spectra". We request a re-evaluation of this conclusion for the Reactor, -

Turbine and Radwaste Buildings based on the additional information provided in this >

letter, We believe these design spectra have adequate margin to meet the .

"Cos cevative, design" definition contained in Section 4.2.4 of the Generic L  !

Implementation Procedure (GIP-2). This change would eliminate the potentially i

' costly requirement for us to use increased factor penalties assigned by GIP-2 when J . making seismic capacity versus demand comparisons involving Generic Equipment ,

Ruggedness Spectra and when performing electrical raceway Limited Analytical Reviews. Boston Edison will continue to treat the design floor spectra for the  !

- Intake and Diesel Generator Buildings as " median centered response spectra" for  ;

-. completion of the A46 program.

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M ' ; New Reactor Building floor spectra have been rigorously developed for a 0.15g Safe Shutdown Earthquake (SSE) .using a state-of-the-art finite element model, . soil-E 'l structure interaction analyses, and current' Standard Review Plan criteria. These new floor spectra satisfy the " Conservative, design" definition of GIP-2, and are enveloped by the Pilgrim design floor spectra for the Reactor Building within the ';

irequency range important to the A46 analysis scope of work. This demonstrates the ,

conservatism resulting from the approaches and techniques used in the late 1960's to produce the Pilgrim design floor spectra. Enclosed for review are descriptions of- -

the new modeling and analyses work, spectra conprison plots, and further discussion  ;

of our conclusions.

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We have made substantial progress in the development of our response to Supplement 1 of GL 87-02. In order to continue this work in the most efficient manner, we would appreciate an early reply to this request. Since this information is submitted in accordance with ):MFR50.54(f) as requested by Generic Letter 87-02, Supplement 1, we do not consider " subject to 10CFR170 fees. If you need additional information to assist your revi n we would be pleased to furnish it.

h Y-YCLL l1

• E. T B6iilette Commonwealth of Massachusetts)

County of Plymouth )

Then personally appeared before me, E. T. Boulette, who being dulv sworn, did state that he is Senior Vice President - Nuclear of Boston Edison Company and that he is duly authorized to execute and file the submittal contained herein in the name and on behalf of Boston Edison Company and that the statements in said submittal are true to the best of his knowledge and belief.

My commission expires: O65cpf /9ff(IC9MI2 [d'.u

'i DATE l NOTARY PUBLIC Attachments:

1. Discussion of Conclusions

2. Descriptions of New Modeling and Analysis Work

3. Spectra Comparison Plots cc: Mr. R. Eaton, Project Manager Division of Reactor Projects - 1/11 Office of Nuclear Reactor Regulation Mail Stop: 14D1 U. S. Nuclear Regulatory Commission 1 1 White Flint North i 11555 Rockville Pike i Rockville, MD 20852 l U. S. Nuclear Regulatory Commission l Region I l 475 Allendale Road i King of Prussia, PA 19406 l Senior NRC Resident Inspector Pilgrim Nuclear Power Station nas/GL8702

r ATTACHMENT 1 DISCUSSION OF CONCLUSIONS New Reactor Building floor spectra have been rigorously developed for a 0.15g Safe Shutdown Earthquake (SSE) using a state-of-the-art finite element model, soil-structure interaction analyses, and current Standard Review Plan criteria. The time history inpui is based on Regulatory Guide 1.60 requirement for free-field ground motions. The details of this work are presented in Attachment 2.

These new floor spectra satisfy the " Conservative, design" definition of GIP-2, and are enveloped by the Pilgrim design floor spectra for the Reactor Building within the frequency range important to the A46 analysis scope of work. Spectra comparisons are presented in Attachment 3. This demonstrates the conse, atism resulting from the approaches and techniques used in the late 1960's to produce the Pilgrim design floor spectra.

Although comparable data is not available for the Turbine and Radwaste Buildings, the conservatism demonstrated by the Reactor Building response spectra results are expected to be present in these other structures as well for the following reasons:

. The Pilgrim design floor spectra for the Turbine and Radwaste Buildings were generated by Bechtel during the same period in time as the Reactor Building, and using the same approaches and techniques, described in FSAR Section 12.2.3.5.3.

• Like the Reactor Building, the Turbine and Radwaste Buildings are also embedded structures, and would be expected to similarly benefit from soil structure interaction effects. This has been demonstrated with approximate analyses performed to compute seismic demand for the IPE-External Events seismic PRA work. The relationship of these three buildings to each other and their foundation embedments are shown in figures contained in Section 12.1 of the Pilgrim FSAR.

. The original Bechtel analysis for each of the buildings used lumped mass stick models with soil springs and resulted in the calculation of building resonant frequencies. A listing of the first two modal frequencies for the Reactor, Turbine and Radwaste buildings is provided below for your information:

Blda. Dir. Mode #1Hz Mode #2Hz Reactor E-W 4.6 12.4 N-S 4.5 11.7 Turbine E-W 3.4 5.9 N-S 4.5 7.0 Radwaste E-W 9.6 22.2 N-S 11.3 23.1 In conclusion, we believe the Pilgrim design response spectra for the Reactor, Turbine and Radwaste Buildings have adequate margin to meet the " Conservative, design" definition contained in Section 4.2.4 of the Generic Implementation Procedure (GIP-2).

ATTACHMENT 2 DESCRIPTION OF THE NEW MODELING AND ANALYSES WORK This attachment consists of the following engineering reports:

• EQE Engineering Report No. 42103-R-001 entitled " Seismic Reanalysis of Reactor Building, Pilgrim Nuclear Power Station", dated July 1993 (BEco document reference SUDDS/RF 93-140).

• Stes enson & Associates Calculation No. 91C2672-C-002 entitled " Soil Properties for 'he Soil Structure Interaction Analysis for the Pilgrim Site", dated Januaiy 1993 (BEco document reference SUDDS/RF 93-029).

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3 vNctNrruaNa A Division of EQEInternational CONS Ul_T A N TS September 21,1993 42103-O-012 N E-93-133 Mr. J.G. Dyckman Civil / Structural Division Manager Boston Edison Company 25 Braintree Hill Office Park Braintree, MA 02184

Subject:

EQE Copyright Statement

Dear Sir:

i:OE Incorporated grants permission to Boston Edison Company to reproduce copies of a!! documents created under purchase order LBR 107049 (EOE Project No. 42103). This permission is granted for internal use only, and for use by 3rd party organizations for future work on Pilgnm Station.

Very truly yours, (42M 2 bCD &

Paul D. Baughman Northeast Regional Manager JLW:cjd I QE Engineenng Consultants 139R Porismouth Avenue . 5tratt i t, NH 03885 . Telephone (603) 778-11(" .1%X (h03) 7715-7495 e..uss n

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