Urban myth. You can't lift a nuke. It is very, very heavy.<br />
There are however suitcase dirty bombs.
Almost word for word what I was going to say. What is your background?
I studied physics, for a while. I have a great interest in nuclear physics.
True! And since the collapse of the Gorbachev regime the KGB have reportedly LOST 20 of them.
It depends on how picky you want to be with the definition. If you are talking mushroom cloud bomb, no. But a plutonium mass can be brought to critical with a tungsten shell causing severe radiation damage to anyone around it for the duration of the critical state such as what happened to Luis Slotin in the accident back in 1946.
I think that's actually a reference to dirty bombs. They're regular explosives that spread radioactive material the way other types of bomb spread shrapnel. But maybe someone can make a small one but it takes so much work it wouldn't really make sense compared to regular bombs.
They're real. They're just not much of a nuke. Good for taking out a city block, but that's about it.