how were Oppenheimer and Groves able to stand at ground zero right after the first atom bomb exploded without getting radiation poisoning?

Question

Speaking specifically to this picture

https://www.atomicarchive.com/history/trinity/afterwards.html

In: 685

Answer 1

I’ve never seen an assay of how radioactive ground zero was for trinity but my assumption would be two things. First they weren’t hanging around for that long and second it probably wasn’t nearly as radioactive there as people think. I also didn’t see anywhere in that picture saying how recently the detonation occurred, the most dangerous time for radiation would be right after detonation. The most active fission products will decay the fastest as well so waiting a few days can drop the activity significantly.

All that said, just because they weren’t getting radiation sickness it doesn’t mean it was a good idea. Radiation exposure can increase the probability of cancer years down the road even if there are no symptoms at the time of exposure. The U.S. exposed a lot of people to radiation from testing the atomic bombs and resulted in a lot of unnecessary cancers. They ended up creating the radiation exposure compensation act as a way to help people who suffered from those mistakes.