ML19344F406
| ML19344F406 | |
| Person / Time | |
|---|---|
| Site: | Vallecitos File:GEH Hitachi icon.png |
| Issue date: | 06/23/1980 |
| From: | Trifunac M CALIFORNIA, UNIV. OF, LOS ANGELES, CA |
| To: | Kerr W Advisory Committee on Reactor Safeguards |
| References | |
| ACRS-CT-1260, NUDOCS 8009150236 | |
| Download: ML19344F406 (2) | |
Text
OW60 My UNIVERSITY OF SOUTHERN CALIFORNIA oy LOS ANGELES, CALIFORNIA 900o7
- trNIVERSITT PARK scHoot oF ENGINEERING DEPARTMENT OF CIVIL ENGINEERING June 23, 1980 Prof. Kerr ACRS U.S.N.R.C.
Washington, D.C. 20555 Re: ACRS Subcommittce Meeting on G.E. Test reactor, June 16 and 17, 1980
Dear Prof. Kerr,
At your request I am enclosing several comrr.ents regarding seismic design considerations for GETR:
NRC requirements for the amplitudes of strong shaking to re-Tha 1.
sult from (a) Possible earthquake on Colaveras fault with M = 7
- 7.5 at 2 km from GETR and (b) Possible earthquake on Verona fault with M = 6 - 6.5 with surface trace at GETR site and up to one meter net slip seem reasonable. This comment is based only on what was stated during the meeting since I did not have an opportunity to review any writing.on this matter so far.
2.
Consideration of strong shaking and the effects of possible thrusting motion beneath the foundation to occur simultaneously seems quite reasonable.
3.
The assumption that the effects of thrusting beneath GETR foun-dation can be considered in essentially static fashion, however, seems oversimplified.
If this dislocation does take place it is very likely that it will be caused by or will cause strong
-shaking. 'If it is to be associated with major fault motion or a side fault dislocation its rise time is likely going to be of the order of one second and possibly shorter.
Double differen-tiation of the accompanying displacements is thus likely to pro-duce rocking and torsional components of angular acceleration which should be applied as dynamic forcing functions simultaneous-ly_with those of strong shaking.
4.
The Dynamic response em 'ysis of the Containment structure can be significantly improved. The material presented during the meeting is based on linear models and assumed superposition 7
8009150 M p
- by.,.
4 Prof. Kerr Page Two Howeyer, considerations based' on the " cantilever model" suggest that only a.part of the foundation area may re-to be valid.
t main in contact with sGrrounding rock and soil medium under-neath, thus leading to a vertical excentricity "d" as in t i
the existing lumped mass model of containment including "d", reduced compliances-corresponding only t
-figure below.
h Here R foundation and with simultaneous shaking R, y and 5.
and y are horizontal and vertical design acce
' location beneath the foundation.since the coupling of X, y a bility for superposition.
y The above consnents are based on the assumption that the wors h
G.E.
representative events are those proposed by the NRC staff and t e Having heard about this reactor site for the first t on.
and their consultants. I do not feel that I know enough to conrnen time on June.16,1980 these or to suggest alternative considerations.
Sincerely,
. DDl-M.D. Trifunac J
MDT:mdm 7
Y.'. ;
g_.
p sp4IT r
?
I Q J.
Q
-x i
.,. t.. e. sa, w-1 N
3***'
y.
t o.v 4 ?,'
ee
. ' =f',
si d.
1 s
, - -