Fictionalized Criticality Accident

1. The screwdriver was against protocols at the time.

2. There is such a device created afterwards called the Godiva.

The plutonium would become white hot and intiate the China Syndrome.

They didn't really throw all the change and metal they had on to the ground, right? Such short exposure couldn't have created lingering radioactivity in a belt buckle.

The character played by John Cusack is a fictionalized version of Louis Slotin, who was criticized even then by some of his colleagues at the experiment for having endangered all of the staff with the way the experiment was conducted.

Yes, contact in this scenario (with this much matter) leads to a chain reaction that releases the energy equal to the mass of the free particles multiplied by the speed of light, squared.

yeah, the scientist in the real experiment even held the carbide hemisphere with his bare hand as the screwdriver slipped. He realized the danger within a few seconds an pulled it away... it was enough for a letal dosage. His comrades reported a "wave of heat" they felt directly after the carbide enclosed the plutonium.