> water is a really, really good insulator against radiation. Absolutely. There is this[1] horror story about a diver who was doing maintenance in a transfer p

> water is a really, really good insulator against radiation. Absolutely. There is this[1] horror story about a diver who was doing maintenance in a transfer pool next to two spent fuel pools. After he was done with the work he found an unidentified object at the bottom of the pool and was instructed to put it in his tool basket. The object was a broken piece of irradiated reactor component. They realised that something is very wrong when the diver was lifting the basket out of the water and the area radiation monitors started to alarm, so they lowered the basket back into the water. On the 10th slide of the document there is a diagram showing the water's shielding as a function of distance. At 1.4 meters there is no dose they can measure while they measure extremely high doses at centimeter distances. 1: https://isoe-network.net/publications/pub-proceedings/symposia/north-american-tc-symposia/fort-lauderdale-usa-january-2011/slides-14/session-iv-1/1756-ritter2011-ppt/file.html https://isoe-network.net/publications/pub-proceedings/sympos...