Well... Yes, anything is possible if you can get the supplies. BUT can you lol? I am not even clicking that link because i already know you cant get the supplies to make one. There is a reason they cost around 50 million dollars to build

(IDK how much one really cost to make, but its pointless to even try.) Even if you were rich enough, and knew the right people for the supplies you couldn't get one nor need one. Do you know how fast you would have a US military bullet in your head from your backyard while you post on here if you got the stuff lol? Shouldn't even post stupid shit like this anyways its what makes people think we are terrorist or something.
If I was the last man on earth I wouldent want a nuclear warhead, this shit isn't even funny when you think about it. But if you really wanna make one just move to North Korea so we can kill you when you finially get one.
(N. Korea)"Yay we got a warhead fear us!!!!!"
(U.N.)"Ok, just have every country in the world drop around 10000 small missiles in a specific spot and lets carve Bush2000 into there countryside."
This is a stupid reply, but asking about an A. Bomb is stupid imo.