[Fresh Wind]

This makes one wonder just how good our nuclear weapons detectors really are at our ports. Considering they can't find this big, old and likely poorly shielded bomb...

Water is an excellent shield for radiation. It is used for that exact purpose in some reactor designs.

[DB]

Yes, that's why I question how well we can detect a nuke in the bottom of an oil tanker filled with oil going into any port USA.