ML19323H271
| ML19323H271 | |
| Person / Time | |
|---|---|
| Site: | Vallecitos File:GEH Hitachi icon.png |
| Issue date: | 05/02/1980 |
| From: | Philbrick S PHILBRICK, S.S. |
| To: | Igne E Advisory Committee on Reactor Safeguards |
| References | |
| ACRS-CT-1242, NUDOCS 8006120302 | |
| Download: ML19323H271 (2) | |
Text
_-
- O SHAILER S. PHILBRICK CONSULTING ENGINEERING GEOLOGIST RHACA. N. Y.14850 407 257.1957 2 May 1980 i
Mr. Elpido Igne Advisory Committee on Reactor Safeguards Nuclear Regulatory Commission 3
Washington, D.C. 20555 Dear Els Reference is made to GE response to my recommendations of 14 December 1979 which response was inclosed with GE letter to you dated 14 April 1980.
The fundamental reason for recommending the additional sub-surface investigations at and beneathh the GETR was to establish the feasibility of isolating the GETR from foundation disturb-ance in the event of displacement of the earth mass overlying the shears eastward and possibly beneath the GETR. Such inform-ation is applicable to solution of the foundation problem re-gardless of whether the shears are the result of faulting or landsliding.
Not mentioned in my letter of 14 December was my serious doubt that the shear exposed in some of the trenches down hill from the GETR is nothing but a plane of failure of a local landslide, not comparable to the shear mapped at the base of the hill above the GETR.
During the meeting on 14 November, in reply to my questioning, it was stated that the lower shear was found only in the trench-es on the flat nose of the hill down hill from the GETR. The shear was not found in the flanking trenches on the sidssof that flat nose. From these statements I drew the conclusion that the lower shear was a local occurrence with short extent in a north-south direction, the lateral direction. This conclusion I stated at the meeting, possibly not as strongly as I should have stated.
Let us consider the effect of the absence of the shear in the flanking trenches on the uphill extent of that shear. The shear is narrow in lateral extent, a fact. The shear would seem to be related to a slump slide, the surface of which slide has been eroded to remove the offsets common to such type of slide, a theory. Slump slides of narrow lateral extent,(in my experience, i
commonly do not attain great vertical extent.
I suppose this may be the result of the side friction or shear resistance being much ' greater relatively than that of a very wide slump slide.)
Thus I would suspect that the lower shear may not extend very far up the hill, possibly not reaching the GETR, If this were the case, the foundation problem would become much less complex, its solu-tion much simpler and isolation something to be seriously examin-ed.
8 006120 30dl
.~
Q e
SHAILER S. PHILBRICK CONSULTING ENGINEERING GEOLOGIST ITHACA. N. Y.14850 317 texas LANE C07 257.ss57 Mr. Elpido.Igne 2 May 1980 The answer to all of the above lies in subsurface investig-ations to define the uphill extent of the lbwer shear. That is why I recommended additional subsurface investigations in my letter of 14 December 1979. If it were my responsibility, I would investigate, but it is GE's responsibility, not mine.
Sincerely yours,
,. Shailer S. Philbrick
- "G
'W
'1 q
p,, _,,.,