[Hodar]

The chips for nuclear missiles and warheads require the ability to withstand a higher-than-average neutron flux during their regular service life and brief exposure to EXTREMELY high neutron flux during the flight of the missile to the target.

I understand the higher than average neutron flux while in storage, and the need to withstand that without degrading. But, why would they need to survive the extremely high neutron flux at the end of a long flight? Once things go 'boom' ... who cares if an accumlator drops a bit?

[Poohbah]

I understand the higher than average neutron flux while in storage, and the need to withstand that without degrading. But, why would they need to survive the extremely high neutron flux at the end of a long flight?

You can't execute any sort of "launch under attack" options without neutron-hardened chips, because otherwise your missiles are vulnerable to a "pin-down" attack (high altitude bursts along their likely egress routes). Also, during the terminal phase, you're going to have a lot of neutron flux from (a) friendly nuclear warheads striking nearby targets and (b) enemy nuclear-tipped ABMs (which we can opt to deploy at any time).