ML19210E802
| ML19210E802 | |
| Person / Time | |
|---|---|
| Site: | Oyster Creek, Palisades |
| Issue date: | 11/08/1979 |
| From: | Hofmayer C Office of Nuclear Reactor Regulation |
| To: | Robert Murray LAWRENCE LIVERMORE NATIONAL LABORATORY |
| References | |
| TASK-03-06, TASK-3-6, TASK-RR NUDOCS 7912130008 | |
| Download: ML19210E802 (3) | |
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November 8, 1979 Mr. Robert Murray Lawrence Livermore Laboratory (L-90)
P. 0. Box S08 Livermore, CA 94550
Dear Bob:
We recently met with Professor William Hall and Dr. John Stevenson to discuss the seismic review of Palisades Unit No. 1 and Oyster Creek Unit No. 1.
We agreed that the methodology and parameters discussed in the enclosed summary should be treated as an interim guide for you to use in your efforts to review the above facilities, if you and your consultants feel that scme other alternative acproacnes are more acpropriate than the approaches outlined in the enclosed summary, please submit to us detailed theoretical and technical data to substantiate your approach.
Sincerely,.
I
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Charles H. Hofmayer, Section Leader Engineering Section Systematic Evaluation Program Branch
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Division of Operating Reactors
Contact:
Henry Lee 492-7807
Enclosure:
As stated cc:
D. Crutchfield P. Kuo H. Levin H: s"9 1550 02l W. Hall, Univ. of IL N. Newmark, Univ of IL J. Stevenson, Woodward-Clyde R. Kennedy, EDAC D. Wesley, EDAC M. Ma, EG&G T. Wambach J. Wetmore 7 91213 o OG Y
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SUMMARY
OF METH006 LOGY AND PARAMETERS TO BE USED IN SEP SEISMIC REVIEWS FOR PALISADES AND OYSTER CREEK
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NUCLEAR POWER PLANTS I
Palisades A.
Soil Properties -
1.
Shear modulus (or shear wave velocity): The equiv, shear modulus "G" of the foundation soil strata at the strain level corresponding to a 0.2g peak ground acceleration should be used. Parametric studies need to be cerformed by varying this property 1 50%.
2.
Poisson's ratio: At this site with high water table (at ground surface), Poisson's ratio 0.15 will be used for saturated sand.
B.
Soil Springs - Since this site has shallow soil overburden (only
+ 100' to bedrock), Luco's aporoach for a rigid surface foundation on a layered media should be used instead of using the procedures developed by Kausel. Kausel's approach may not be appropriate because it cannot take the flexibility of the bedrock into account.
The containment structure is only embedded partially on one sice.
Thus, embedment effects can be ignored.
C.
Soil Damoing - The following values may be used for soil damping (material damping plus geometric damoing):
% of Critical Damoina Rocking 10 Swaying 15 Vertical 20 As suggested by Professor Hall, some sensitivity studies about these values should be performed.
D.
Composite modal damping - using the median values of the structural damping ratio recorrended in the NUREG/CR 0098, the composite modal damping may be obtained by either of Biggs, Roesset or Tsai's method.* Care and judcment must be exercised when the composite modal camping exceeds the structural damping by a very large amount. Dr. Stevenson noted that the NRC has not accepted and licensed a nuclear power plant with composite damping higher than 12% of the critical.
E.
Structural Analysis Method - Modal analysis by the Response Spectrum Method.
1550 022
- Sensitivity studies using the lower bound values (the values as suggested in R. G. 1.61) of the structural damping ratio should be performed to assess the impact of deviations from current criteria.
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II. Oyster Creek A.
Soil Properties 1.
Shear modulus: The weighted average shear modulus should be used (G = + 1500 KSF corresponding to the strain level of 2.)-
5 x 10 f
2.
Poisson'e. ratio: Since the water table is high, V = 0'.35 - 0.J is recommended.
B.
Soil Springs - Derived from the elastic half space. theory. Embedment effects may be considered by using the approach developed by Kausel or lovak.
C.
Soil Damping - The following values may be used for soil. damoing (material damping plus geometric damping):
4 of Critical Damoino Rocking 15 Swaying 20 Ve'rtical 25 D.
Composite Damping - Same as Palisades E.
Structural Analysis Method - Same as Palisades 1550 023