ML19329C470

Seismic Review.

ML19329C470
Person / Time
Site:	Davis Besse
Issue date:	10/28/1969
From:	JOHN A. BLUME & ASSOCIATES, ENGINEERS
To:	US ATOMIC ENERGY COMMISSION (AEC)
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ML19329C469	List: ML19329C468 ML19329C470
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CON-AT(49-5)-4011 NUDOCS 8002140850
Download: ML19329C470 (8)

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~i SEISMIC REVIEW _

DAVIS-BESSE NUCLEAR POWER STATION THE TOLEDO EDISCN COMPANY (Docket No. 50-356)

The attached is a list of comments resulting fecm a preliminary review of the PSAR reference documents (see attached list) for the Davis-Sesse Plant. The review was primarily directed toward seismic considera t ions ,

but a general review of the structural characteristics and design con-cepts was perfor~ed. The questions and ccmments have been arranged in the following categories:

1. Site and Environment ll. Nuclear Steam System 111. Reactor Building and Other Structures IV. Class ! Piping Systems V. Class ! Equipment k

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3463 JCHN A. GLUME & ASSOCI ATES. ENGINEERS go0214

1. SITE AND ENVIRONMENT

1. It is not clear which response spectra and/or acceleration time-history will be used in the analysis, in Appendix 2C, it is stated on page 2C-36 that either of the following may be used:

a. The spectra in Figures 111-5 and ill-6, pages 2C-47 and 2C-48 respectively,

b. The time-histories recommended in Section Ill.D.2.d and Table 111-4, pages 2C-32, 2C-35, and 2C-42 res:ectively, or

c. Both the response spectra and the time-histories.

On page 5.17, section 5.2.2.3.8, it is stated that Housner's aver-age response spectrum normalized to the peak ground accelerations for the site will be used.

Thus the applicant will be using any one of several criteria, none of which are necessarily equivalent. We request that the applicant clarify the seismic design criteria and state specifically which spectra are to be used in the analysis. In addition, for the time-history analyses, we request that the applicant provide a compar-ison of the criteria spectra and the spectra from the time-history.

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11. NUCLEAR STEAM SYSTEM 1

Please describe in more detail the analysis procedures that will be used to determine that the nuclear steam supply system (reactor vessel, steam generators, reactor coolant oumps, piping, etc.) will meet Seismic Class I cri teria (Section 3 1.2.4, page l 3-3.PSAh). Include in this discussion the following:

a. A detailed description and sketch of the proposed math-ematical model(s) of the system, including a discussion

] of the degrees-of-f reedom and methods of l umping masses, I determining section properties, etc.

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. b. The mathematical model(s) to be used for the reactor ves-j sel internals.

c. A discussion of the analytical procedures to be used, in-ciuding the methods of computing periods, mode shapes, >

l design accelerations, displacements, shears, moments, etc.

i i d. An explanation of which " actual earthquake records" are to l

l be used in the time-history analyses and a comparison of j the response spectra from these earthquakes and the spectra I postulated for the site (PSAR Figures ill-5 and lil-6, pages 2C-47 and 2C-48).

} e. An explanation of how it will be determined that the LOCA and maximum earthquake time-histories are conservatively applied such that the maximum structural response is obtained.

Are the LOCA and earthquake time-histories assumed to start at the same time? If so, would it be possible to obtain greater response if the earthquake were started at some in-crement of time, such as 10 seconds, either before or af ter l 1

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f. A listing of the damping values to be used.

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5-Ill. REACTOR BUILDING AND OTHER STRUCTURES

1. Will the possibility of a pipe break in the space between the shield building and the steel containment vessel be considered in the design? Will the vacuum breaker valves be adequate under these conditions?

2. How will the personnel lock and equipment hatch be designed to resist seismic loads? How will the seismic loads be determined?

3. How will the piping and electrical penetrations be designed to resist seismic loads? How will the seismic loads be determined?

4. Will the Class I structures be designed for the combined Icading of the tornado pressure drop, wind, and missile?

5. Please provide justification of the use of fixed bases in the mathematical models of the shield building, containment vessel, and internal structure (page 5-17 and Fig. 5-7) .

6. How will seismic shears and moments be transferred from the internal structure and containment vessel into the shield building base slab?

7. How will relative oeflections between adjacent buildings be accounted for in the design of piping systems which run be-l tween buildings?

8. What provisions will be made to transfer seismic and wind shear forces across ccnstruction joints?

9. Please expand the lists of structures, piping, and equipment (mechanical and electrical) in Appendix 5A to include the location of each item and the type of seismic analysis that 4

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e will be performed for each item.

For those Class I items which will be lccated within or adjacent to Class Il structures please explain in detail what precautions will be taken to ensure that the failure of the Class 11 structure will not adversely affect the Class I items. For example, what will be the design loads on the protective enclosure which sur-rounds the critical items in the Turbine Building (pages 5-42 and SA-3)? How will these loads be determined? Provide a similar discussion for the Service Water Pump Structure and the Diesel Generator Enclosure.

10. Please describe the procedures to be used in the seismic analysis and design of structures other than the containment structure, such as the Auxiliary Building.

II. In Appendix 5A, page SA-4, it is stated that the maximum value of the response curve is used whenever it is considered imprac-tical to perform a dynamic analysis. This statement is unacceot-able, and it is neccessary to know exactly which systems will be treated by dynamic analyses r.'ethods and for which systems it will be considered " impractical" to perform a dynamic analysis.

The use of the " maximum value of the acceleration response curve" (page SA-4) is not an adequate procedure in itself for seismic design. This " maximum" acceleration can te greatly exceeded for multi-degree-of-freedom systems. If this procedure is used, the applicant will have to justify for each case that :Se results are conservative, it would be adequate criteria for caly those items that can be idealized as single-degree-of-f reede.n systems.

12. What provisions have been mace for the instr.llation of seismograchs?

JCHN A. BLUME & ASSOCIATES. ENGINEERS

• 2 IV. CLASS I PIPING SYSTEMS Please describe in detail the analysis and design procedures to be used to determine that Class I piping systems will meet Class I criteria. Include in this discussion the following:

a. The methods to be utilized to determine the input for the piping analyses. Include a comparison of the pos-tulated spectra for the site and the spectra determined from time-history of ground acceleration used in the analysis.

b. A discussion of the analytical procedures to be used. '

including the methcds of ccmputing the stiffness and mass matrices, oeriods, and mode shapes, and the pro-cedures for computing design accelerations, displace-ments, shears, moments, and stresses.

c. Typical mathematical models for several piping systems for the Davis-Besse Plant.

m J C h* N A. BL UME & ASSCC!ATES. ENGINEERS

m V. CLASS I EQUIPMENT Please describe the procedures to be used to assure that the Class I equipment (both mechanical and electrical-tanks, pumpt 3tc.)

will meet seismic design criteria. Provide a summary of all such pieces of equipment and the types of the seismic analyses to be performed.

JCHN A. SLtJME & ASSOCIATES. ENGINEERS ,

.. . w SEISMIC REVIEW REFERENCE DOCUMENTS Davis-Besse Nuclear Power Station The Toledo Edison Company Docket No. 50-346 Construction Permit Preliminary Safety Analysis Report, Volume i Preliminary Safety Analysis Report, Volume 11 Preliminary Safety Analysis Report, Volume lit i

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_3 JOHN A. BLUME & ASSCCIATES. ENGINEERS