ML19210B585
| ML19210B585 | |
| Person / Time | |
|---|---|
| Site: | Crane  |
| Issue date: | 03/03/1971 |
| From: | Hall W, Newman N, Webb Patricia Walker NATHAN M. NEWMARK CONSULTING ENGINEERING SERVICES |
| To: | |
| Shared Package | |
| ML19210B580 | List: |
| References | |
| NUDOCS 7911110023 | |
| Download: ML19210B585 (4) | |
Text
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N A T H A N M.
NEWMARK CONSULTING ENGINEERING SERVICES 1114 CIVIL ENGINEERING BUILDING URBANA. ILLINOIS 618o1 3 March 1971 DRAFT Re;7atater;
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COMMENTARY RacMvai W/Lir t:123
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ON FINAL S AFETY AllALYS IS REPORT FOR THREE MILE ISLAND NUCLEAR ; TATION -- UN IT I METROPOL! TAN-EDISON COMPANY AND JERSEY CENTRAL POWER #1D L!GHT COMPANY AEC Docket No. 50-289 by W. J. Hal l, W. H. Wal ke r, and N. M. Nevriark 1.
Seismic Desian Criteria Earthcuake Hazard --
The seismic design for the plant was carried out for a Design Basis Earthquake characterized by 0.12g maximum horizontal ground acceleration to the extent of insuring containment and safe shutdown; also, the design was made for an Operating Bas:s Earthquake characterized by a maximum horizontal ground acceleration of 0.06g.
As noted in our report on the PSAR (Ref. 4), we concur in these design level s for use in the seismic design of this plant.
Buried Pioino --
The description of the approach followed by the applicant for buried piping as given on pagas 5-7Ga and 5-76b evidently indicates the manner by which the applicant vrould have analyzed the piping.
Of concern is the matter as to how the applicant handles the piping at points near major structures where it 1566 242 391111002.2
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2 runs into the structure and through a wall.
The applicant should indicate whether the design that was carriad out was such as to provide the necessary ductil ity at this location through backpacking in the pipe trench and/or wall so as to accom.modate the small motions that might be expected between the rock and the structure.
Al te rnat ivel y, if the piping were carried in the pipe tunnel, this should be indicated, as this would provide means of accommodating relative motion.
Reactor I n te rnal s --
The analysis procedure followed in the design of the reactor internals, as described on page 3-46 of the FSAR, is that given in Babcock and Wilcox topical report BAW-10008, Part I, Revision I (Re f. 3).
The approach followed therein for the analysis of the reactor internal s is acceptable to us.
It was made for higher levels of base grcund acceleration than those for the current pl ant design.
The second topical report, BAW 10008, Part II, Revision I refers to the fuel assemblies stress deflection analyses for loss of coolant accident and seismic excitation (Ref. 3(b)) and in this case the analysis was made for values of earthquake excitation which were lower than those indicated as the design cri teria for the pl ant.
The applicant should indicate whether, with an appropriate review of this analysis in terms of the DBE seismic hazard for the pl ant, this aspect of the design was adequate.
Buildina Analysis --
The seismic design approach adopted for the buildings is summarized on pages 5-18 and thereaf ter in the FSAR.
It is indicated that the vertical and hori:ontal seismic components at any point in the shell were added by summing the absolute values of the response (that is, stress, shear, moment, or defl ections) of each contributing f requency (sic) due to the vertical motion to the corresponding absolute values of the response of each contributing f requency (sic) 1566 243
3 to the horizontal motion.
On the assumption that the appl icant means each of contributing mode instead of frequency, we believe the approach is satisf actory.
In general, the approach adopted for the seismic analysis of the shell follows classical methods and so f ar as can be ascertained the material s presented in the FSAR are acceptable.
Desian Stresses --
The applicant states in Sectic" 5.2.3 that the design of the prestressed reactor building was made such as to have a low strain elastic response for all design loads. The stresses presented in Table 5-3 for various load combinations appear acceptable except that they do not include tabulations for loading conditions 31 and 32, which are for the Design Basis Earthquake.
The applicant should indicate whether the stresses and behavior for these loading conditions were found to be acceptable.
Responses Resul tina f rom Vertical Motions --
The statements in FSAR suggest that appropriate amplification was taken into account in the analyses carried out in the design of the structure, and the applicant advises orally that such was the case for both structures and piping.
It is assumed that this will be documented in an amendment to be filed shortly.
Pioino Analvses --
The general description of the method of dynamic analysis followed for piping systems is given on pages 5-76a and 5-766.
Further ampl ification is given in the topical report by Gil bert and Associa tes (Ref. 2).
The Gil bert and Associates topical re po rt indicates th at the method of Siggs and Roesset was employed for the analyses carried ou t.
We are advised that the floor response spectra which were used in the piping analyses are being regenerated and will be re-examined when they are submi tted in the near fu ture.
No further 1566 244
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4 comment on the piping analyses will be made at this time other than to express a desi re to examine typical stress values at critical points in certain of the major piping systems for both the DBE and OBE loading combinations, with comparisons with allowable stress values for these conditions.
2.
Class 11 I tems of Ecuicment in Cl ass i S tructures The applicant should indicate whether there are any Cl ass I items located within Class 11 structures.
If so, these should be identified, and the protection provided to insure their ability to function adequately under earthquake excitation should be documented.
3.
C ri t i cal i tems of Cont rol and ins trumen tation The appl icant indicates on page 7-2a that the adequacy of critical controls and instrumentation will be documen ted in report BAW 10003, " qual i fi-cation Testing of Frerection System Instrumentation".
As yet we have not seen this report and no further comment is made at this time.
4.
Aircraft Imoact Desian The applicant addresses tSis question in Appendix Sa.
We are advised that the applicant is completing an addi tional eval uation, and ou r comments will await this submi ttal.
REFERENCES, l.
" Final Safety Anal ysis Report -- Vol. I throuch IV, including Amendments 14 and 17," Metropol i tan-Edison Company and Jersey Central Power and Ligh t Company, AEC Docket No. 50-239,1970 and 1971.
2.
" Dynamic Analyses of Vital Piping Systems Subj:cted to Seismic Motion,"
Gilbert and Associates, I nc., Topical Report No. 1729, May 23, 1970.
3.
(a) " Reactor Internal Stress and Deflection due to Loss-of-Cool an t Accident and Maximum Hypothetical Earthquake," Babcock and Wilcox Report BAW-13008, Part I, Revision I, June 1970.
(b) " Fuel Assembl y S tr:ss and Deflection Analysis for Loss-of-Cool ant Accident in Seismic Excitation," Babcock and Wilcox Report S AW-10008,
Part II, Revision I, June 1973 (Proprietary).
4.
" Adequacy of the Structural Cri teria for Three Mile isl and Nuclear S tation Unit I," Me t ropol i tan-Ed ison Company (AEC Docke t 50-289), Repo rt to AEC Regul atory S taf f by N. M. Newmark and W.
J.
Hal l, Decembe r 1367.
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