ML19261B006
| ML19261B006 | |
| Person / Time | |
|---|---|
| Site: | McGuire, Mcguire  |
| Issue date: | 01/03/1979 |
| From: | Ketchen E NRC OFFICE OF THE EXECUTIVE LEGAL DIRECTOR (OELD) |
| To: | Hand C, Lazo R, Luebke E BODEGA MARINE LABORATORY, Atomic Safety and Licensing Board Panel |
| Shared Package | |
| ML19261B007 | List: |
| References | |
| NUDOCS 7902090187 | |
| Download: ML19261B006 (3) | |
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. r CH!t u ON. D. C. NC1.5 s..., i e January 3,TW9FD'E'IC Zgg
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Robert M. Lazo, Esq., Chairman Dr. Emmeth A. Luebke Atomic Safety and Licensing Board Atomic Safety and Li as,i'n rd o
U.S. Nuclear Regulatory Commission U.S. Nuclear Reg ' tj#y 'CoFints's1 Washington, D. C.
20555 Washington, D.
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J ff Dr. Cadet H. Hand, Jr., Director 9
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Bodega Marine Lab of California
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DUKE POWER COMPANY Docket Nos. 50-369 & 50-370
[ William B. McGuire Nuclear Station, Units 1 & 2)
Gentlemen:
This is to inform the Board of certain information provided in a preliminary fashion by one of the NRC Staff consultants relating to criteria in buckling of steel containment structures. The report is attached, along with a Staff evaluation of this matter.
In this connection, the Staff believes that the information does not adversely affect the evaluation conducted by the Staff in this case.
The problem of potential buckling of the steel shell because of the asymmetric pressure loading generated in the ice condenser was considered in the McGuire containment vessels.
The stability of the overall shell, as well as the individual shell panels, was investigated.
The investigation was accomplished through the use of the following references:
1.
Wilson, Edward :nd Ghosh, Sukmar; " Dynamic Stress Analysis of Axisymmetric Structures Under Arbitrary Loading," Report No. EERC 69-10, College of Engineering, University of California, Berkeley, California, September, 1969.
2.
NACA TN 3786, " Handbook of Structural Stability, Part VI -
Strength of Stiffened Curved Plates and Shells," by Herbert Becker, New York University, July,1958.
3.
NACA TN 3781, " Handbook of Structural Stability, Part 1 -
Buckling of Flat Plates," by G. Gerard and H. Becker, New York Univer-ity, July, 1957.
4.
NACA TN 3782, " Handbook of Structural Stability, Part II, Buckling of Composite Elements," by G. Gerard and H. Becker, New York University, July, 1957.
79020901M
. Reference 1 is a computer program used to calculate the stresses in the containment shell due to the asymmetric loading. The stresses thus obtained are compared to the critical buckling stresses as calculated from reference 2.
The stability of individual shell panels is investigated by considering the panel first as a flat plate and then as a curved panel through the use of references 3 and 4, respectively.
Duke Power has indicated that buckling has been considered in all loading combinations, and the minimum factor of safety against buckling is 3.27.
This minimum factor of safety results from considering the panel as a curved plate under the combined action of axial and shear loadings.
We have reviewed the applicant's design criteria as summarized above, and conclude that the McGuire containment design provides acceptable margins to resist the specified asymmetric loads.
If you require any further information, please let us know.
Si e ely, I
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dward G. Ketchen Counsel for NRC Sta f Enclosure as Stated cc (w/ encl.):
J. Michael McGarry, III, Esq.
William Larry Porter, Esq.
Shelley Blum, Esq.
Mr. Jesse L. Riley Atomic Safety and Licensing Board Panei Atomic Safety and Licensing Appeal Panel Docketing and Service Section
ENCLOSURE flRC STAFF EVALUATION OF FACTORS OF SAFETY AGAItiST BUCVLIrlG In a report entitled " Stability Criteria for Primary Metal Containment Vessel Under Static and Dynamic Loads" written for GE by R. L. Citterley of Anamet Laboratory, Inc., a factor of safety against buckling ranging from 2.0 to 2.75 is reconnended.
Also recently the 1977 summer addenda of the ASME Code requires a factor of safety of between 2.0 and 3.0 against buckling depending upon the applicable service limits.
Due to the lack of experimental data and uncertainties in establishing the theoretical buckling load, we have an ongoing technical assistance program to study this issue.
It is expected that any final design recom-mendations or guidelines resulting from this program will be evaluated for possible use in our licensing review work. We are not at this time in a position to make any changes to previously accepted criteria.
However, we have urged applicants to study their buckling criteria further and form a strong technical basis for their approach. As indicated above, through the help of our outside consultant, the Staff will develop our technical position further.
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