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UNITED STATES NUCLEAR REGULATORY COMMISSION WASHINGTON, D. C. 20555
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DEC 18 Bdi MEMORANDUM FOR:
Division of Engineering
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!l N. Knight, Assistant Directorfor Components and Structures Enginee l
Division of Engineering F. Schauer, Chief
@ Structural Engineering Branch
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Division of Engineering FROM:
P. T. Kuo. Section B Leader Structural Engineering Branch Division of Engineering
SUBJECT:
COMMENTS ON SEISMIC VERIFICATION PROGRAM, DIABLO CANYON UNIT 1 The following are my comments on the qualifications of the proposed companies and on the adequacy of the proposed verification program submitted by PG&E dated December 4, 1981.
Comments On Qualifications 1.
R. L. Cloud, R. F. Reedy, and W. E. Cooper all appear to have extensive experience in mechanical component design and piping stress analysis. They do not appear, however, to have had significant experience in structural analysis and design or in seismic analysis of structures. Both Drs. Cloud and Cooper are mechanical engineers by training. Mr. Reedy is a Professional Structural Engineer, but his experience has been mainly in quality assurance and mechanical component design. There is no indication in their resumes that they have had experience in concrete structural design or seismic analysis of such structures. Unless there are other experienced structural engineers in their organizations, I feel the experience presented is in-sufficient for them to perform verification wor < for structures.
2.
It is believed that a good portion of the work will be performed by other engineers in their respective organizations.
It is essential that those engineers who will actually perform independent reviews are ex-perienced and qualified. Knowledge of the qualification of the three principals is helpful but not sufficient.
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>l R. Vollmer, Director 2-Comments On Verification Program 1.
Pages 13 and 14, Section 5.3 It is noti clear if there is any criteria for " modification and. inter-pretation" of the formal procedure referred to in this program.
It is similarly unclear how a conclusion can be made that "it will be possible to determine g errors in the plant seismic qualifications" simply by use of engineering interpretations of error sources.
It seems that a serious generalization is being made here based on unspecified engineering interpretations.
2.
Page 14, Item 1 It is not clear what are the criteria for the word " insignificant."
3.
Page 15, Section 5.4.1 It is suggested that a dynamic model of the auxiliary building be in-dependently developed. A review of the PG&E existing model may not be sufficient.
4 ~. Page 16. Section 5.4.1 The criteria for acceptance based on the fundamental mode frequency is not adequate. Mode shapes and selective floor response spectra should also be compared.
5.
Section 5.4.1 4
It is suggested that one buried tank and one outdoor water storage tank be included in this program.
6.
Page 18, Section 5.4.4 A quasi-static method of calculation may or may not be conservative de-pending on the details of the calculation.
It can not be generalized.
Furthermore, the basic interest of this program is more than "to determine that equipment meets design criteria or stress limits" as indicated. An assessment of the adequacy of the entire design process and the quality assurance of-the design should be made and reported on the basis of the number of sample cases where variations are greater than 15% and of the percentage of exceedance in the sample lot.
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R. Vollmer, Director 7.
Page 21, Section 6.0 To avoid any modification later on, an independent field verification should be made before any requalification is performed.
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P. T. Kuo, Section B Leader S.tructural Engineering Branch Division of Engineering cc:
J. Knight F. Schauer B. Buckley T. Sullivan
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