These SOP's are older stuff, there are very different munitions that have a different demand.
In addition to the atomic tall boy, and fatman bombs we need to make different preparations for Neutron flux; nuclear EMP; cobalt salted munitions, and that puts us up to date.
in a few years we will have issues with unidirectional discharge munitions, essentially high energy gamma ray lazing devices, and if current directions of research pan out, nuclear isomer munitions of halfnium/actinium may be a concern if they prove to be feasable.
In any event a properly oriented and rivetted trench, and sealed water food supplies are the major necessities.
an even better improvement would be photonic momentum or molecular beam epitaxy (MBE).
a triad of laser beams would be used to levitate and position an aliquot of polymer into position and cured by a 4th beam of sufficient quanta to induce polymerization.
In any event a properly oriented and rivetted trench, and sealed water food supplies are the major necessities.