6.
FissionFragments and Fall Out: When the atomic explosion
occurs, we said a Uranium 235 atom fissioned into two large particles
knewm as fission fragments and numerous neutrons, The two large fission
fragments are carried with other debris into the atmosphere, Due to
the intense -heat thoy are initially in vapor form, As the atmosphere cools
after the explosion these fission fragnents solidify on moisture droplets
and dust in the atmosphere, They fail out. of the atmosphere in the form
of dust. The fission fragments are unstable and decay to a stable element
by emitting electrons, in the form of Beta rays, and electromagnetic
radiations, called gamma radiation,
Other radiations may be emitted, but
we are not generally concerned with them. This radioactive dust termed
"fall out" is the main source of our radiation hazard,
‘7.
FallOut:
This active dust we have termed "fall out" is carried
by atmosphericwinds to far places, ‘we are likely to observe fall out
on Enivetok as a result of the nuclear expe: iments to be run in the near
future, If "fall out" is present it would present a danger to all personnel
here,
We will guard against this danger.
We will have trained personnel
here with us who will precede us prior to reentry to the island with
instruments designed to detect radiation and measure its quantity. ‘Ve
°
- will remove as much of this active dust from the island as possible, a
procedure we loosely refer to ‘as. decontamination, We will mark off areas
that are dangerous, A procedure for the above will be orgainzed within
this unit,
Detailed instructions will be presented at a later date,
For
your safety and the safety of your associates it is mandatory that these
instructions be carried out,
.
8, Next Lesson: Your next lesson will include detzils of an atomic
danger to personnel of radiation.
explosion and theda