68006
However , too few of the neutrons produced by U fission are energetic enough to induce further fissions in U , so no chain reaction is possible with this isotope .
 location: U
Given options, please tell me the categories of all the listed entity words.Output format is "type1: word1; type2: word2". 
Option: location, person, organization 
Text: {0} 
 Entities: U 
Answer:
 location: U