310.1

Particle Appearance
The particles from one group were radioautographed for the

minimm practicable length of time.

Those which were found to be

radioactive were classified according to appearance. The results are
presented in Table 3.16. Representative particles are illustrated in

Figures 3.30 to 3.36.

The large particles from Shots 1 and 2 appeared

to be coral, whereas the smaller particles had a more crystal-like

appearance. Fallout from Shot 3 had 4 smaller percentage of coral
particles, most of which were in the larger size ranges; the vemining

particles had a fuzed, porous, or ashlike appearance.

3.1062

Location of Activity in the Particle.

The particles from the sacond group were treated by the method
employed by Cadle24/ to determine their internal activity distribution,
This process could not resolve the location of activity on particles
velow 149 pe. These data are presciied in Table 3.17 and selected
radioautographs ara illustrated in Figures 3.37 through 3639e Active
ity on tha Shot 1 particles was on the surface in 60 to 70 per cent of

the number exantinad, evenly distributed throughout 71 to 36 per cent

ef the particles and unevenly distributed throughout 1 to & per cent
of the particles examired.

The activity on the outside of the Shot 3

particles varied from 32 to 37 per cent.

Uniformly radioactive

particles varied from 3 to 55 par cent and activity was unevenly dis=tributsd in zero to 13 per cent of the particles, The percentage of
particles with activity on the outside generally increased directi:-

with size, while the percentage of uniformly radioactive particies
generally decreased with size. No tremis were noted in the small
group where the activity was ecattered randomly throughout the
particle.

There was no apparent ccrrelation batween the location of
activity on the particles and their physical anpearence.

Fige 3020

Shot 1 Transparent Crystalline Particle 49-149 n.

91

Select target paragraph3