[Justa]

Ok, you do realize that the uranium fuel in the atomic bombs was only a few pounds much of which was consumed by fission in the blast?

The Fukishima plants have thousands of tons of uranium onsite which are at risk of burning whereby radioactive particulate is released into the environment with very little fission to consume the fuel beforehand.

A few pounds vs. thousands of tons is a significant scaling issue.

[norwaypinesavage]

"you do realize that the uranium fuel in the atomic bombs was only a few pounds much of which was consumed by fission in the blast? The Fukishima plants have thousands of tons of uranium."

You are comparing the mass of weapon grade fissionable material in a bomb with the total mass of spent fuel rods. First, only a fraction of the mass of a spent fuel rod is uranium. Second, there is no weapon grade uranium in a spent fuel rod.