Whiel I agree with your statements, it should be noted that sometimes scuba-diving in nuclear reactor's pools isn't as safe and fun as originally intended.
[A diver not briefed on avoiding unknown objects picked up a highly activated bolt laying on the pool floor and received a substantial amount of radioactive dose.]
This just verifies that water is a good shield against radiation. The slides explained that any proximity to, not to mention physical contact, with the object would be highly dangerous but having a mere 1.4 meters of water in between the human and the object the dosage would be negligible.
http://www.isoe-network.net/index.php/component/docman/doc_d...
[A diver not briefed on avoiding unknown objects picked up a highly activated bolt laying on the pool floor and received a substantial amount of radioactive dose.]