Color dodge and radial blur do not create explosions. If you really want to make one look good, find out what a real explosion looks like. As-is, these look nothing like explosions; the first, at best, looks like the flash from a gun-barrel (stretching it) and the second looks closest to sparks, but that's also stretching it.
Again, look at real explosions.
Thanks Noel, but I don't care.