[hoagy62]

I remember the Sovs saying they were going to make it 100 MT, but it was Sahkarov (I think) who suggested that was too big and that they scale it down by half.

I don’t think anyone makes them that big anymore. I know that the biggest we made was 15MT (Castle Bravo), and that was by accident.

[SauronOfMordor]

The limiting factor is the delivery system.

100kt seems to be the optimum size.

A 100MT bomb would need a SpaceX super-heavy to lift it.

[IndispensableDestiny]

I remember the Sovs saying they were going to make it 100 MT, but it was Sahkarov (I think) who suggested that was too big and that they scale it down by half.

The Tsar Bomba was designed as a three stage fission-fusion-fission device. The final stage was a depleted uranium tamper and casing. This was replaced with lead to decrease the amount of radioactive fallout. As it turned out, the Tsar Bomba was very "clean."

Removing the third stage reduced the yield from an expected 100 MT to 50 MT. The bomb was an act of political intimidation against the US. It was never meant to be deployed.