750 RADS would be lethal for almost everyone receiving it. Iodine would be irrelevant. Given the effects of dispersal over thousands of miles, the entire Japanese people would have to be wiped out first. The Australian group has denied being the source of this claim. I posted all this info to Dr Brownstein days ago in response to one of his blog notices in my email.
Here is a site explaining that the claim of 750 RADS hitting the West Coast is a fabrication: