ML20107C389
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UNITED STATE $
l ATOMIC ENERGY COMMISSION WASHtNGTON, D.C. 20545 e
AUG l 4 574 DOCKET NO.:
50-219 LICENSEE
- JERSEY CENTRAL POWER AND LIGHT COMPANY FACILITY : OYSTER CREEK SUMARY OF MEETING HELD ON AUGUST 15, 1974 TO DISCUSS LIQUEFACTION ASPECTS OF SITE On August 15, 1974, at Bethesda, members of the staff met with represent-atives of Jersey Central Power & Light Company (JCP&L) to discuss lique-
' faction aspects of the Oyster Creek Site in the area of the site proposed for the liquid - solid radwaste building. Attached are copies of the proposed agenda and a list of attendees.
Discussion Dr. Harry Ham described the site and the foundation in'the vicinity of the proposed radwaste plant. A few feet of granular fill is underlain by Cape May Sand, an upper clay layer which is overconsolidated with'about one-third of its volume composed of sand lenses, an Upper Cohansey Found-ation of low density sands, a Lower Cohansey Foundation of higher density sands, a lower clay layer which is also overconsolidated and contains sand lenses, and, finally, the Kirkwood Foundation.
Earlier reactions have been founded on the denser Lower Cohansey Foundation.
The presentation by Dr. Ham explained the approach and analyses which have been used to support their plan to locate the foundation on or in the Cape May Sand (just below the granular fill).
The design earthquake used in the analysis has a peak acceleration of 0.22g as estimated by Housner in 1963 for an M7 intensity earthquake. The equiv-alent number of cyclic stresses caused by this earthquake was taken as five.
Cyclic tests were conducted on undisturbed and remolded soil specimens.
The Staff's reaction to the presentation may be sunmarized as follows:
(1) The duration and number of equivalent cycles assumed for the earthquake m*y be too short and too few when compared to the earthquake motions required by regulatory guides.
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. (2) The site investigation and the number of soil samples tested is on the light side.
In-situ densities are needed and are easily attain-able at the site.
(3) Liquefaction safety factors based on 20 percent specimen strain are not appropriate. The licensee should use the initial liquefaction
' Safety Factor.
(4) The safety of the proposed foundation design depends mainly on the earthquake motions (time history) assigned to the site.
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p ohn Riesland j
Operating Reactors Branch #3 Directorate of Licensing 3
Enclosure:
1.
List of Attendees 2.
Agenda t
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O LIST OF ATTENDEES AUGUST 15, 1974 OYSTER CREEK RADWASTE JohnRiesland(Parttime)
AEC.L C. R. Montgomery GPUSC L. W. Heller AEC.L W. P. Gamill AEC.L H. M. Horn Woodard-Moorhouse & Assocs., Inc.
Yves Lacroisc Woodard-Moorhouse & Assocs., Inc.
DavidJaffe(Parttime)
AEC.L Steve Chow Woodard-Moorhouse & Assocs., Inc.
doe Bennett AEC.L 4
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9 an o 54 DISTRIBUTION:
AEC PDR BGrimes Local PDR WGammill Docket JKastner ORBf 3 Rdg MSpangler L Rdg RBallard VMoore TJCarter RCDeYoung SVarga RDenise PErickson DSkovholt OGC
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KGoller R0(3)V DMuller SATeets JStolz ACRS(16)
KKhiel ASchwencer DEisenhut DVassallo WButhler OParr RClark PCollins RVollmer WHouston RPurple DZiemann Glear GKnighton GDicker BYoungblood WRegan JMHendrie FSchroeder RMaccary VStello RTedesco HDenton JKnight SPawlicki LShao 1
TNovak Dross TIppolito CLong GLafaas VBe'ticmya 1
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O Proposed Agenda Meeting on August 15,'1974 with AEC Staff To Discuss Liquef action Aspects of Site of Proposed Liquid-Solid Radwaste Building Oyster Cteek Nuclear Power Station 1.
Existing and Proposed Facilities Plan of Site and Locations of Borings 2.
Generalized Subsurface Conditions a)~~Generalized Soil Profile b)
Profile of Standard Penetration Resistance in Cohansey Deposit c)
Detailed Stratigraphy of Upper Clay Layer 3.
Seismic Parameters (for SSE) a)
Obtained from Forked River NSP PSAR,,1,, p. 2-44 a,,x = 0.22g I
='MM-VIf b)
Magnitude c)
Equivalent number of significant cycles (Neg) 4.
Concept of Factor of Safety in Terms of Strain Criteria a)
Definition b)
Strain criteria 1.
initial liquefaction 11.
20% double-amplitude ( 10% average strain) 4
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5.
Methodology for Evaluation of Liquefaction Potential a);
Identification of deepest soil layer that might
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have potential to liquefy b)
Evaluation of factors of safety against initial liquefaction and the accumulation of various strain levels c)
Comparison of computed factors of safety with acceptable values 1
6.
Determination of Field Cyclic Shear Strength (Sc} f0#
Selected Deformation Criterion a)
Correlation between S and laboratory cyclic c
triaxial test value at corresponding deformation 4
criterion b)
Determination of laboratory triaxial cyclic 4
stress-strain relationships i.
undisturbed specimens i
11.
stress-controlled, cyclic CIU triaxial tests iii.
relating laboratory cyclic stress ratio
__(a to number of cycles required d
c tx to reach specified deformation criterion iv.
influence of confining stress (6 }
c laboratory cyclic triaxial test results 4
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Determination of Earthquake Induced Cyclic Shear Stress (tg) - Simplified Procedure j
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Rigid body i(RB) " UV* " max _*
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Deformable body i(DB) " Ti(RB) d T
8.
Liquef actfoiPotential of Cohansey Deposit
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a)_ Below el -28 ft i.
existing reactor founded at that level ii. ' marked increase in denseness below that level b)
Above el -28 ft 1
Calculated factors of safety against initial' liquefaction, and an. accumulation of strain of 20% double-amplitude.
9.
Liquefacti'oT ?otent'ihl of Uppe'r Clhy'Lhy'er
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