ase - 
Some fission products possess half lives of seconds or less, while others 
have half lives greater than a million years. Irradiated fuel elements 
containing the entire spectrum of fission products decay from time of 
discharge in a manner illustrated by the curves in Figures 1 through 3. 
Heat released from fission products is given in Figures 4 and 5. 
Types of Reactors 
Purpose: Nuclear reactors can be classed first as to purpose. For 
each purpose there is a corresponding fuel and blanket material as shown 
in Table 1. 
TABLE 1 
Classifications of Reactors According to Purpose 
Purpose Fuel Fertile Material New Fuel 
Pu production | ore 738 Pur? 
(0.71% ) (In natural U) 
High flux y3? Optional Optional 
experimental 
Mobile power y=? None None 
yo33 production ue? m3 p33 
(breeder) Full or partial 
Commercial power 
a. Thermal sein U mo3- p33 
ye33 
b. Fast ys? yo3® Pur>? 
239 
53 
DECLASSIFIED 
