It's 1973 and Israel is in danger of being overrun. They send out a single aircraft armed with a tactical nuclear bomb in case it's needed as a last resort. Fortunately, it isn't, but unfortunately the aircraft is shot down and the bomb lost. After years of laying in the desert unexploded, the bomb is salvaged by enterprising Arabs who sell it to an arms dealer, and it eventually makes its way to the United States under the control of a neo-Nazi madman.

The Israeli military may have flaws but losing a nuclear bomb just doesn't sound like one of them. It is true, however, that weapons-grade plutonium (Pu 239) is hard to detect. It primarily gives off alpha particles and small amounts of low energy gamma rays which can easily be shielded from detectors. Even-numbered isotopes of plutonium tend to have spontaneous fission reactions which emit neutrons, but these forms of plutonium would be present only in small amounts. Most neutron detectors only work from a distance of a few meters. A bomb lost in the desert could be challenging to detect.

If inhaled, plutonium is one of the worst carcinogens known to humanity . Otherwise, it's comparatively safe. If it were a strong radioactive emitter it would have limited usefulness in bombs. First, it would pose a hazard to military personnel handling the bombs. Second, ionizing radiation could accidentally disable or set off the bomb's electronic firing circuits. Finally, a strong radiation emitter would be a beacon for easy detection and countermeasures against a bomb when it was being delivered.

Plutonium does have some serious handling problems other than radioactivity. Small pieces of plutonium are pyrophoric. While the large piece contained in a bomb would not burst into flames, in contact with air it could get hot enough to cause other materials touching it to combust. Pouring water on plutonium to cool it would be a very bad idea. It could cause a small but rather nasty chemical explosion. Plutonium is usually coated with something like beryllium, at least in part, to prevent such reactions.

When the Arabs find the bomb they remark that it's warm. This could have been due to the energy given off by alpha decay. The plutonium probably would've been coated or sealed in a protective container, otherwise it would most likely have started a fire. Nevertheless, at least some of the Arabs supposedly become fatally ill with classical radiation poisoning.

Yes, in May of 1946 Dr. Louis Slotin, a Manhattan Project scientist, died of severe radiation sickness caused by plutonium. Slotin was engaged in an experiment called tickling the dragon's tail in which two beryllium-coated plutonium hemispheres were brought together in close proximity. The combined mass of the two hemispheres equaled the critical mass required to initiate a fission chain-reaction; that is, if they touched. The idea was to come as close as possible without touching. Slotin was holding the top hemisphere with his left hand when the screw driver separating them slipped. The room was filled with a blue glow and a massive emission of neutrons.

Slotin immediately pulled the hemispheres apart but still received a fatal dose of radiation. He died nine agonizing days later. His left hand swelled up, developed severe blisters, and gangrene shortly after the incident. Doctors kept it packed in ice rather than amputating it. Slotin was thirty-five at the time of the tragic incident.

The plutonium sphere in the movie would not have had enough density to reach critical mass without detonating the explosive that would have surrounded it. This would have violently compressed the plutonium enough for it to go supercritical and create a nuclear explosion. As long as plutonium does not go supercritical, as mentioned earlier, it's relatively safe to handle. We suspect that the deadly case of radiation poisoning in the Arabs was mostly a Hollywood creation.

The nuclear bomb is eventually refurbished and detonated in the US, nearly causing a nuclear war with the Russians who are initially blamed. Fortunately, the hero of the movie, Jack Ryan (Ben Affleck), manages to unravel the neo-Nazi's dastardly plot and prevent nuclear war all in a single afternoon while wandering around smoldering wreckage near ground zero of the nuclear explosion.

Affleck and his girlfriend (Bridget Moynahan) narrowly escape the blast and go on to a blissful existence. On this point it's hard to make a statement. We have no idea how far they were from the blast or the extent of their exposure to radioactive fallout. However, it's tough to believe that things could have turned out so well. The movie seems to gloss over the aftermath of such an explosion.

Perhaps a wake-up call is not needed in the post 9-11 era, but it is true that democratic governments do reflect the will of the people. If the people become complacent, the government eventually follows, leading to a more dangerous situation. Although it doesn't provide solutions, exploring unthinkable issues through movies can be useful. While The Sum of All Fears is not glitch-free some parts of it are almost too real.