How survivable are tanks against nuclear weapons?
This is something I was wondering about recently. Let's say NATO used a B61-4 against an attacking armored force (wiki says the max yield is 45kt). How many tanks would such a weapon actually be expected to destroy or incapacitate?
Google tells me a modern tank battalion would typically cover between 2 and 5 miles of frontage. Playing around with nukemap tells me that with an airburst optimized for 20 psi of overpressure you'd have a blast radius of a little over half a mile. Serious radiation would have a radius closer to a mile and for serious burns (presumably not applicable to a buttoned up tank crew) the radius is two miles.
This makes it seems like realistically a medium sized tactical nuke could take out maybe couple of of companies worth of tanks. That's less impressive than I thought. I understand it would absolutely gut any supporting infantry and supply columns, so you'd have a bunch of tanks on their own. No infantrymen to protect them and no fuel or ammo resupply. Am I missing anything here or are nukes not as effective against armored forces as we'd imagine?