[ RadSafe ] probability of incidence of radiological event comparison between nuclear power plant and dirty bomb attack

[ChiChang Liu]

Dear Radsafers,

Recently my colleagues and me debate about limited radiological response 
resource allocation (budget planning).
Most of them believe that the probability of a dirty bomb attack event 
is quite small. We should not spend too much money on such a topic.
And they think most of the resource should spend on preparedness of 
nuclear power plant emergency including risk communication with people 
living around power plant.

Is there any literature mentioned about the comparison of probability of 
incidence or risk between these scenarios ?
Any information is appreciated !

ChiChang Liu