ML20235N389

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Forwards Vols I-III of Generation of In-Structure Response Spectra for Fort Calhoun Unit 1, for Review.Upon Approval Alternate Seismic Criteria for 1990 Outage Mods Currently in Design Will Be Considered
ML20235N389
Person / Time
Site: Fort Calhoun Omaha Public Power District icon.png
Issue date: 02/21/1989
From: Morris K
OMAHA PUBLIC POWER DISTRICT
To:
NRC OFFICE OF INFORMATION RESOURCES MANAGEMENT (IRM)
Shared Package
ML20235N392 List:
References
LIC-89-199, NUDOCS 8903010192
Download: ML20235N389 (2)


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Omaha Public Power District 1623 Harney Omaha. Nebrasha 68102 2247 402/536 4000 February 21, 1989 LIC-89-199 U. S. Nuclear Regulatory Commission

. Attn: Document Control Desk Mail Station PI-137 Washington, DC 20555

References:

1. Docket No. 50-285
2. Letter from 0 PPD (K. J. Morris) to NRC (Document Control Desk) dated December 2, 1988 (LIC-88-506)

Gentlemen:

SUBJECT:

Request for Alternate Seismic Criteria Review, Approval and Safety Evaluation Report 1

Omaha Public Power District (0 PPD) requested the review of alternate seismic criteria for Fort Calhoun Station Unit No. 1, in Reference 2. The request was accompanied by Criteria Document Volumes 1 and 2 which identifed the development criteria and methodologies for design and analysis of several categories of systems and equipment. The criteria and methodologies used to generate and justify the design spectra were included in that submittal. At that time, OPPD committed to provide seismic design spectra, and an overview of the training and procedural controls that will govern the implementation of the criteria. Also in a November 7,1988 telephone conversation OPPD agreed to provide implementation guidance.

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The use of the " Alternate USAR Appendix F Criteria" will be procedurally controlled (following NRC acceptance of the criteria). Technically justified boundaries, between the use of existing and alternative criteria, will be in defired for implementing the use of the alternative criteria in analytical

,$ models. These boundaries will be defined as a natural consequence of employing go. good analytical modeling practices. These will be described within mechanical e oo engineering instructions as part of Production Engineering Division procedures

$8 for controlling the use of the criteria.

{y Boundary criteria will include the following considerations:

mathematical models that have boundary conditions which reflect goed

<g decoupling practices; SSo-

  • significant lumped masses and eccentricities; ol valve operator flexabilities;  ;

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. U.,S. Nuclear Regulatory Commission LIC-89-199

? age 2 restraint and equipment stiffness based on generic or calculated values rather than assumed rigidity;

( significant thermal end seismic anchor movements, input at boundarles; ard f

use of frequency response spectrum which envelope restraint locations or use of multiple level frequency response spectra methods.

The Design Basis Documentation (DBD) for systems, to which the alternative criteria is applied, will be updated to reflect that the alternate criteria has become the Design Basis for those affected portions of the system within the prescribed boundaries. This new criteria would then be the governing DBD for future reviews and modification except as otherwise justified.

The seismic design spectra is provided in the attached " Generation of l In-Structure Response Spectra, for Fort Calhoun Unit 1," Volumes 1, 2 and 3,  :

which describes the seismic hazard and soil-structure interaction analysis performed for the Auxiliary, Containment, Shell, Containment Internals and Intake Structures for the Fort Calhoun Station, Unit No.1.

Detailed procedural controls and associated training program criteria will be developed prior to implementation of the criteria. After guidance is developed it will be incorporated into OPPD's Production Engineering Division Manual as mechanical engineering instructions. Training requirements will be defined and conducted in accordance with OPPD's training palicy prior to program implementation.

OPPD requests a timely review of the alternate seismic criteria and issuance of a safety evaluation report. Upon NRC approval we intend to consider alternate seismic criteria for 1990 outage modifications which are currently in design.

Should you have any questions concerning this matter, please contact us.

Sincerely, WN k" "J"'i'

/ Division Manager Nuclaar Operations KJM/sa Attachments c: LeBoeuf, Lamb, Leiby & MacRae, w/o attachments R. D. Martin, NRC Regional Administrator, w/o attachments P. D. Milano, NRC Project Manager, w/o attachments P. H. Harrell, NRC Senior Resident Inspector, w/o attachments

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