The Compton Effect has nothing to do with EMP. When a nuclear weapon explodes it releases electromagnetic energy across the entire spectrum, but this is only at the moment of the fission/fusion reaction which is extremely short lived. Hence EMP.No. The EMP is caused by the effects of the initial nuclear radiation, produced by the reaction, upon the air. I seem to remember something called the Compton Effect.
If it was any sort of nuclear weapon masses of people would be dead or dying from radiation effects.