atom bomb expiration dates

do atom bombs have an expiration date? a point beyond which their yield would be minimal or they wouldn’t work at all?
would it be relevant in the timeframe of a human lifetime or would the monkeys who would succeed us and become our masters be able to use our weapons to blow each other up?

Someone just saw “Sideshow Bob’s Last Gleaming”, didn’t they?

(In case you don’t get the reference… )

Thermonuclear weapons contain tritium, a radioactive isotope of hydrogen with a relatively short half-life (12.43 years). Once the tritium decays, the warhead’s yield will definitely drop; however, thermonuclear weapons are initially triggered by fission reactions using uranium-235 or plutonium-239 (these days, I think plutonium is more often used). U-235 has a half-life of 713,000,000 years, and Pu-239 of 24,360 years, so the fission part of the bomb will be around for a a good bit longer than the fusion part–for a very long time in a uranium bomb.

IANANuclear Physicist, but I would think a thermonuclear device whose tritium had all decayed would still go off as a fission bomb; from a military point of view, it would be something of a fizzle, but still very destructive, along the lines of the Hiroshima or Nagasaki bombs (both pure fission bombs of, respectively, uranium and plutonium types). However, some modern bombs get very fancy using various technical tricks to maximize yield and to use what would ordinarily be sub-critical masses of fissionable material; I don’t really know what they would do without any fusion material. Again, though, a “dud” from the P.O.V. of a superpower military might be very powerful and lethal from another P.O.V. (terrorists, or some hypothetical future civilization of intelligent cockroaches or super-advanced rodents who haven’t yet developed atomic weapons)–a yield of “only” a kiloton could still wreck a city center and strew all sorts of radioactive nastiness over a wide area.

What about the chemical explosives, triggering electronics, and the batteries which power the detonators? How long can those be expected to last?

I’m pretty sure they do routine maintenence on the bombs… so the other parts besides the core of the weapon shouldn’t be a problem (wires, batteries, detonators).

But i’m not sure what they do about the tritium.

Warning: Spoiler

This was a major plot device in the Tom Clancy novel “The Sum of all Fears”. The H-bomb made by the terrorists was somewhat of a fizzler because they didn’t know to replace the tritium. It was still an A-bomb though.