Those guys were heros. They may knot have known (no one really did at the time) about the radiation and long term effects. Still, they knew a little, which was why they wanted to fly through the cloud. Knowing that and doing it anyway takes some real guts.
Smithsonian "Air & Space" magazine had a short story from one of the guys that flew F-84s up close to the detonations. A scary read. Like your brother, most all of those guys are dead from the radiation they absorbed.
I have been very, very sad all day. My brother’s daughter posted pictures of her dad’s grave with the red, white and blue decorations on Facebook today. He died in May, 2006, my husband died in July, 2006, my bil 2 weeks later and then my mom died in January, 2007. She would have been 103 a few months later. All of these came 2 years after my daughter died. So, I have just been missing them but kinda glad they can not see what this country has become. My brother would be disgusted. Am going to have to get off this site. Makes me very sad.
I knew an old rancher lady who showed me big glossy 8X10s her husband took of many bomb tests in the Pacific. He was a Navy photographer. There were shots of the setup, blast, mushroom, aftermath. I asked what happened to him. “Oh, he died of cancer in 1959.”