After Hours

Geek Trivia: Overdose of tragedy

What was the highest dosage of radiation ever suffered by a human being from a conventional nuclear accident -- the highest lethal rem count ever inflicted outside the detonation of a nuclear weapon?

For those of you interested in the various scales that quantify major disasters, we have a new entry for you: The International Nuclear Events Scale. The INES is an eight-point (0 to 7) numeric scale developed by the International Atomic Energy Agency for communicating the level of danger represented by a nuclear accident, designed so international authorities can comprehend and respond to the threat quickly, appropriately, and effectively.

Before we go any further, this is not the oft-misquoted list of buzzwords such as Bent Spear and Broken Arrow that show up in oh-so-many Hollywood movies, though such terms do have some basis in reality. Those are code phrases used by the U.S. military to describe incidents involving nuclear weaponry, while the INES is a civilian system used to describe events involving non-weaponized nuclear systems and materials.

Put another way, Broken Arrow refers to a missing nuclear bomb. INES Level 7 refers to a nuclear reactor meltdown.

An INES Level 0 event represents absolutely no danger to anyone or anything, but it was at least enough of a hiccup that the incident observer felt it worth reporting to international authorities. Think of it as the nuclear equivalent of the Check Engine light in your car.

In contrast, the poster child for an INES Level 7 event — and the only example of the worst possible INES rating — is the Chernobyl disaster, rated by most authorities as the most lethal and dangerous nuclear event in human history, short of those that actually involved nuclear weapons.

This is not to say that the Chernobyl disaster released the greatest volume or intensity of radiation ever to result from a nuclear accident. The lethality of the Chernobyl accident is largely attributable to the fact that it released radioactive fallout into open air.

Winds then carried that fallout over a devastatingly large area. This wind-borne fallout exposed millions of innocent bystanders to increased cancer risks, and it rendered an entire city uninhabitable for the next few thousand years.

Still, the highest dose any single individual received from the Chernobyl disaster was an estimated 1,600 rems — definitively lethal but far from the record dose suffered by a human accident victim.


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Jay Garmon has a vast and terrifying knowledge of all things obscure, obtuse, and irrelevant. One day, he hopes to write science fiction, but for now he'll settle for something stranger — amusing and abusing IT pros. Read his full profile. You can a...

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