218
OTHER MAJOR ACTIVITIES
Orsi] hole VIGBA
Void
yal
_Z
n
\ '
~
“
M
é
ay
/
.
“i
'
Approx
chimney
boundary
'
‘
t
et
"t
‘
-.
'
'
3
Rubble
an \
f
we
.1
,
feet and
11
r
Rock
type - Granogicrite
.
Cepth of our-ai - 939°
1
Yieia- Sxt
1
‘7
Cavity
a3!
radius +53
volume of rsoole
apeve
A-A'-2,500,CCO ft
Rubble
poresity- 29%
:
:
The effects of a contained
nuclear explosion in granite
are illustrated in the schemuatie cross section (on the
left) of the Hardhat site.
Postshot investigations
revealed a cavity radius of 63
28S
~
Parente - ee
iy
!
|
ot
RT
‘
b 7
|
3
, |
ae ne wee!
|
Approx
3
Daundary of
iT
wail rock
1, incompetent
1. Exploratory drift
Tot
a chimney
height
above the shot point of 2S1
feet.
Rock in the chimmey
Was broke sufficiently to allow undertaking a block caving mining experiment. Donald Rawson, Lawrence Radition Laboratory geologist,
eXamines (in the photograph
below) broken granite in the
chimney produced by the
nuclear detonation.
Rawson’s position is 89 feet above
the shot point and 10 feet
inside the chimney.
The Hardhat experiment,
together with the experience
gained in Projects Rainier
(a 1.7-kiloton explosion ih
|
-
Prddle
of
0
10
tuff) and Gnome (a 3.1-kileton explosion in bedded salt)
has provided sufficient infor-
radioactive glass
SCALE
==
(
t
30
=
50
=
feet
mation to warrant iadertask-
ing a pilot-seale
project.
industrial