1946 started with Operation Crossroads, the Nuclear detonations at Bikini Atoll that resulted in the accidental exposure of all fo the ships, both target ships and the support ships when a radioactive steam cloud spread all over the ships irradiating about 70% of the ships of the Pacific fleet at the time.
These ships had to be cleaned to be useable and their focus was to prevent radiation sickness that was seen at Hiroshima and Nagasaki.

They didn’t know the long term effects of radiation, they did not have the ability to measure it well, the devices of the time were prehistoric compared to a few years later and all of the sailors had film badges that were limited to 2 Rads. Guess what they were all overexposed!

It is appropriate that the last two postings here would reveal everything you wanted to know about the total disregard civilians in this work, the dumping of radioactive materials into the Bays, not only San Francisco Bay but every port on the West Coast, Hawaii, Guam and even Norfolk got a little bit of radiation from trying to clean the ships.
The record stands for itself: