Even the Fun kiddie-math (NASA) admits the astronauts would absorb 11.4 Rad in under an hour! But how much is that, really?
According to the United States Nuclear Regulatory Commission, the lethal dose of radiation is in the range of 400 to 450 rem. This level of radiation causes death to around 50 percent of a population that has been exposed over a period of 30 days.
Rads, rems, really? Well, it depends on what *kind* of rads your rems are, which NASA kiddie math ignores!!
For x-rays and gamma rays, 1 rad = 1 rem = 10 mSv
For neutrons, 1 rad = 5 to 20 rem (depending on energy level) = 50-200 mSv
For alpha radiation (helium-4 nuclei), 1 rad = 20 rem = 200 mSv
11.4 * 2 (both ways) = 22.8 per "moon trip", if multiplied by high-energy neutrons (20) or alpha (20), would be 456 rems which is GREATER > than the 450 rem called lethal, and that OVER A 30-DAY PERIOD!!
Meanwhile, the "acceptable" risk is (now) said at 3% cancer risk increase over a lifetime... how the bio-data change, when the narrative needs some new tweaking...