Would a human body be irradiated by nuclear explosion, or just blown away?

50 megatons, 1 mile? They'd be inside the fireball, and those hills would cease to exist. If they were industructable I expect they'd be lofted up by that fireball somewhere above the stratosphere.

50 megatons is really, really big.

Here is good nuclear bomb effects calculator.

https://nuclearsecrecy.com/nukemap/

Put in your yields and and you'll get a decent idea of effects at different distances, both shock wave and thermal effects, and ionizing radiation. There are some terms you'll want to get familiar with, eg. PSI (pounds per square inch). For example, a 50 megaton bomb exploded at ground level will turn a house to matchsticks from 10 miles away.

Yeah, 50 megatons is huge. In fact, that's the largest ever created: Tsar bomba was 50 MT. The fireball was 5 miles wide. It destroyed buildings 34 miles away.

Trivia: It's said that because the Soviet era guidance systems weren't very accurate, the Soviets focused on bigger bombs that didn't need to be delivered exactly on target. The US had better systems, and could therefore focus on making more, smaller bombs that could be delivered more accurately.

ETA: Keep in mind nukes were designed to detonate in the air to maximize the blast radius and effects. A ground blast loses a lot of energy into the ground, hills, buildings, etc.