WinSP MBT: Das Reich

[MarkSheppard]

Originally Posted by RecruitMonty

It is said they only figured out the dangers posed by radiation much later.

During the Manhattan Project, fallout wasn't actually even taken seriously or known if at all -- hence the disbelief by Groves about radiation casualties at Hiroshima and Nagasaki in late August 1945 when Japanese news started talking about it.

Essentially in the Manhattan Project, radiation poisoning was considered to only be a danger to those within the prompt zone of the bomb -- e.g. those within 700 to 1000 meters of the device when it initiated -- and subject to about 10,000 Rads (100 Grays) of instantaneous ionizing radiation from the fission reaction itself.

This was considered to be of minor interest, as that zone nearly neatly overlapped the 20 PSI radius (600 meters out), where

"Heavily built concrete buildings are severely damaged or demolished."

Also, unlike TRINITY (100 foot tower), the Japanese attacks were airbursts at several thousand feet above ground level, so weren't considered to be at danger for causing a lot of contaminated ground.

Reference: (Groves disbelief of Japanese Radiation Poisoning)
Telephone Conversation between General Groves and Lt. Col. Rea, Oak Ridge Hospital, 9:00 a.m., 25 August 1945.