Note too that the related sped up radioactive decay would give Noah a beta-radiation dose (from the 40K atoms inside his own body, which for these purposes is basically all of the radioactive atoms inside a person) of about 50kGy per day (adding the background rate from the crust would up that to about 70kGy). Either way, that’s a fatal dose every few seconds.
That is an insane amount of radiation–10 times the dose inside the worst-contaminated parts of the Chernobyl reactor immediately after the meltdown. Except this lasts for 6 months.