Maybe if you put some more details in the background this piece would be a little stronger. So if this explosion was in the city and you could see how destructive this was or if it was in the woods or something, something that would show what was exploding.
Maybe its just me and this minimalist kick I have been going through lately but I like the fact that its in a white space, maybe it seems a little floaty and if you could find a way to ground it but not add a wealth of color beyond the explosion it could keep it as the central focus of the piece without distracting too much from it. Again I just kinda like the idea of a simple piece :P
You could put in a horizon line to ground the composition... I like the idea of giving some other background elements for context - if you wanted to keep it minimal, maybe you could just keep them at the edges, as if the closer stuff has already been destroyed by the blast.