ML20196E074

Submits Items Re Resolution of USI A-40, Seismic Design Criteria, on Which Public Comments Should Be Sought. Data Indicates That Results of Deconvolution in Analysis of Deeply Embedded Foundations Questionable

ML20196E074
Person / Time
Issue date:	02/12/1988
From:	Bagchi G Office of Nuclear Reactor Regulation
To:	Baer R NRC OFFICE OF NUCLEAR REGULATORY RESEARCH (RES)
Shared Package
ML20151D709	List: ML20196E074 ML20196F258 NUREG/CR-4991, Notification of CRGR Meeting 130 on 880309 to Review Proposed Draft Resolution for USI A-40 Seismic Design, & Discuss NUREG/CR-4991 Evaluation & Proposed Improvements to Effectiveness of NRC Generic Communications
References
REF-GTECI-A-40, REF-GTECI-SC, TASK-A-40, TASK-OR NUDOCS 8802260122
Download: ML20196E074 (2)

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NUCLEAR REGULATORY COMMISSION wassmo tou. o. c. 20sss February 12, 1938 k ..... /

MEMORANDUM FOR: Robert Baer, Chief Engineering Issues Branch Division of Engineering Office of Nuclear Regulatory Research l

FROM: Goutam Bagchi, Chief Structural and Geosciences Branch Division of Engineering and Systems Technology Office Nuclear Reactor Regulation

SUBJECT:

RESOLUTION OF USI A-40, "SEISMIC DESIGN CRITERIA" SUGGESTIONS FOR INVITING PUBLIC COMMENTS ON SPECIFIC ISSUES DURING PUBLIC COMMENT PERIOD We have concurred with the USI A-40 package that is scheduled for CRGR review.

However, we want to bring to your attention some items for which the public I coments should be specifically sought. These items have come to our attention from a quick evaluation of LOTUNG data and use of specific provisions of the

. draft resolution on actual licensing cases.

Depth of Embedment: LOTUNG data indicates that the results of deconvolution in the SSI analysis of deeply embedded (>40m) foundations would be question-able. A similar concern can be expressed for very shallow foundations (<.5m).

Public should be asked to provide cornments as to the reliability and con-servatism of the SSI analysis in these cases.

Damping and Shear Modulus: A number of analysts who performed post test l correlation studies found that they had to reduce damping considerably in  !

their analyses to match the observed results. In other words, the responses l predicted by use of allowable damping were too low. A similar concern has been voiced regar6 ng the use of shear modulus values obtained from the laboratory tests. P olic should be encouraged to corrent on these items.

Subsystem Modeling. For modeling seismic subsystems, the current staff practice as well as the proposed revision in Standard Review Plan (SRP) 3.7.2 and 3.7.3 indic.te that the NSSS components can be analyzed as  :

coupled seismic subsystem i.e., the system is rigidly attached to the j structure. LOTUNG measured data for a simulated steam generator loop 1 indicate that the best correlation between the observed and predicted data is obtained when the simulated system is assumed to be pinned. This could )

be a utatter of concern for seismic analysis of coupled subsystems in existing plante. 'Public should be asked to coment on this issue. i Our review of the SSI analysis for an operating plant indicates that i if the ground motion input spectra used by the licensee do not adequataly  !

account for site specific characteristics, the floor response spectra  !

resulting from a soil-structure interaction (SSI) analysis could be reduced by l 60% to 80% compared to the ones computed using the ground motion consistent with the unique site characteristics. l QqqbOk ff' Attachment 2 to Enclosure 2

2 Thus, the staff has concern regarding the acceptance of such reductions for both alternatives provided in SRP 3.7.2. When this reduction is coupled with the nonconservatism identified in the above correlation studies, we feel that the public should be asked to comment on the realism and conservatism of such reductions, and whether or not some limits should be placed on the spectral value reductions to account for uncertainties inherent in SSI analysis, if'you need clarifications regarding the above items, we will be able to meet with you for a further discussion.

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\'s" Goutam Bagchi, Chief Structural and Geosciences Branch

\'(l(kN, Y Division of Engineering and Systems Technology

. cc: L. Shao J. Richardson R. Bosnak m F. Hebdon J. Conran

, jg-h']fv K. Shaukat N. Chokshi T. Cheng

Contact:

H. Ashar X21374 1 i

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Enclosure 3 to the Minutes of CRGR Meetina No. 130  :

Proposed Generic Letter on Removal of Organization Charts from Tech Specs  :

March 9, 1988 TOPIC C. E. Rossi (NRR) and E. Butcher (NRR) presented for CRGR review a proposed Generic Letter that would ?ermit licensees to remove organization charts from  ;

plant Technical Specifications. The proposed action implements a planned line '

item improvement in the ongoing NRR Tech Spec Improvement Program. Copies of the briefing slides used by the staff to guide their presentation and the dis-cussions with the Committee at this meeting are enclosed (see Attachment to this enclosure).

BACKGROUND l The documents submitted by the staff for review by CRGR in this matter were transmitted by memorandum dated February 22, 1988, T. E. Murley to E. L. Jordan; that package of documents included the following

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1. Information for CRGR Review of Proposed Action (as required in Section IV.B. of the CRGR Charter) l l

2. Oraf t Generic Letter, undated, "Removal of Organization Charts f rom Technical Specification Administrative Control Requirements," and attachments as follows:

a. Enclosure 1 "Guidance for Removal of Organization Charts from Technical Specifications"

b. Enclosure 2 "Markup of Westinghouse Standard Technical Specifications"

! 3. Model Safety Evaluation Report (SER) for Proposed Removal of Organization

, Charts from Individual Plant Tech Specs ,

CONCLUSIONS / RECOMMENDATIONS l As a result of their raview of this matter, including the discussions with the staff at this meeting, the Committee recomended in favor of issuing the proposed Generic Letter, subject to several minor clarifications (to be coord-inated with the CRGR staff), as follows:

1. In Enclosure 1 to the draft Generic Letter (at p. 2, subparagraph 2.),

delete the words ". . . in the of f site organization. . . ." to clarify that the normal office location for the responsible corporate executive may actually be onsite.

1 J 2. Make a similar change to the wordirg of Section 6.2.1.c. in Enclosure 2 i

! to the draf t Generic Letter for the same reason. '

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54 CRGR MEETING ,

MARCH 9, 1999 TECHNICAL SPECIFICATIONS ALTERNATIVE FOR ORGAN!!ATION CHARTS l

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I Attactnent to Enclosure 3 )

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GENERAL REQUIREMENTS _

I L/NES OF AUTHOR /W RESPONS/B/L/7V,' AND COMMUN/CAMONS MUST BE DOCUMENTED BY-

/ ORGAN /ZAHON CHARTS, -

// FUNCHONAL DESCR/PMONS OF DEPARTMENT RESPONS/B/L/HES/RELAHONSH/P3

//L KEY PERSOWNEL ./OB DESCR/PT1\CWS

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ORGANIZATION REQUIREMENTS:

1 i OFF-SITE -

D.ES/GNATED CORFORATE OFr/CER

\ RESPONS/BLE FOR:

• OVERALL PLANT NUCLEAR SAFerf

• ACCEPTABLE STAFF PERFORMANCE /N-L OPERA 770NS,

// MA/NrENANCE,' AND ,

//L TECHN/OAL SUPPORT

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• $ 5 I i g i 0 t i a l t I,

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Enclosure 4 te the Minutes of CRGR Meeting No. 130 '

Discussion of NL' REG /CR-4191 - Improvement of NRC Generic Communications March 9, 1988 I

The Committee discussed the recommendations of NUREG/CR-4991, "Evaluation f and Proposed Improvements to the Effectiveness of U.S Nuclear Regulatory j Cosumission Generic Communications." No recommendations resulted from j the Committee's discussion of this topic at this meeting. The Committee t t

will continue its consideration of this matter at a tuture meeting.

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