You have shielding for your rig like a Faraday Cage? And what about the antenna wiring outside?
Those of us that concentrate on long distance communication via bouncing radio waves off of the ionosphere, watch the Sun and solar weather during the day. We will have some warning before such an event would impact us.
But I was referring to the 20 year old and older all tube equipment that is not affected by EMP and the like... like modern solid state and surface mount technology. Art Collins tested a KWM1 transceiver in a nuclear test blast... it worked fine afterward.
You would be surprised at the ability of modern Hams. We may use some equipment from last century to do it. We can even build spark gap transmitters if needed.
LLS