What kind of shape are our nuclear weapons in? Used to be, you’d have to test them to find out. But the State Department’s Bureau of Arms Control, Verification and Compliance has some good news: Over the last decade, our ability to predict how our aging nukes will perform–without resorting to explosive testing–has greatly improved.
There’s still a problem, though. The last time the U.S. conducted a nuclear explosive test was in 1992. So, while the State Department thinks we can now assess the condition of our nukes better than before, there’s really no way of knowing how accurate those assessments really are-since there has been absolutely no explosive testing to confirm the predictions.
No nuclear explosive testing in 20 years is a very bad sign. Anything can happen in 20 years. Also, when you are mathematically extrapolating into regions unknown, then danger is everywhere. The first rule of modeling: Do not confuse your model with the real world. New things can pop up that you weren’t smart enough to anticipate.
Do you remember Chernobyl?
There was a design flaw that was masked until the reactor was run at very low power generation during a test.
… A bigger problem was a flawed graphite-tip control rod design, which initially displaced coolant before inserting neutron-absorbing material to slow the reaction. As a result, the SCRAM actually increased the reaction rate in the lower half of the core.
Moving into new territory due to extreme age might unmask lurking problems. In the case of US nukes, these problems might lower yields.