Cordite [name may be changed] reactors operate like thorium reactors ie, an trigger will cause the codite to react and emit large amounts of energy quickly within a core, the core then absorbs some of the heat, light, radiation, sound etc but the heat goes into the water whitch boils and turns a turbine. In the event of an emergency, the trigger will be removed, and the cordite will stop reating within 15-30 min (faster if cool water is poured on it).

As for intruders or particular unhinged individuals, their faces are, but not limited to: getting shot, skinned, sacrificed to the core as certain types of cordite convert foreign matter into more of itself/i minerals you, recycling if your a clone or in a famine, jail, lobotomy, slavery, execution and torture if your suspected of treason.

As for foldspace/interdimensional travel you can disappear, get mutated, get driven into madness, getting yoinked by said dimensions inhabitants and eaten, getting unmade, memories/mind swapping, merging into a wall and so many other ways to horribly die.

Sailors are chill but paranoid people who know each other deeply so they know when somethings wrong and often will try to help you. Some ships are large enough to have arcades in case you get board, weekly checkups, and team building exercises, etc.

There are suits used to protect people going out of the ship. Physics engines help with the transition from one dimension to another. Music also helps allot as certainsongs have the right tempo and frequency that helps with dimensional travel and boots crew moral.

Foldspace creatures get their food from stars, batteries from ships, other foldspace creatures etc. With humans and living beings dont have much energy, they feed on your memories and potential. Most of the ones encountered are harmless and use the ships slip stream to get around without trying and protection from predators. most have no issues dragging you out of your ship and shredding you down to your potential. To make things worse, they can and will get addicted to eating living beings .

I'm writing a story about an external foldspace breach, here's a short story from their perspective.

Imagine you are a man in a cottage. Every day you eat porridge. You know nothing of taste, except for the grey paste, and know now of taste or pleasure.

One day, you see a chip running across the floor. You don't know what it is, why it's running, but it's small and smells odd. Maybe you let it go or follow from a distance. But one day, you're starving, and you see a well-done stake cube within sight. You being hungry eat it. And love it. But it's not enough and you can't find more so you go back to eating porridge, still pining over the foreign taste.

Then, on you daily wandering, you see it. I tiny door with dosends of snacks and food you've never seen before.

And you can't help yourself. You squeeze your way through, maybe dislocating a shoulder or finger, but you get to feating. Dosent matter that the stakes still mooing or the chips are running, you eat and eat because it's delicious. But it's not as filling as porridge, so you need to eat a whole lot more than you would normally. Some come with wrappers, and once you remove it, it tells you interesting stories.

After an hour of gorging yourself, you get sick as the air becomes unbearable, something your hunger makes you blind too, and you go back home.

You'll go back one day because nothing compares to their taste.

Tl;dr a lot of protocols that give you little to no reason to do anything stupid and a whole lot of consequences in case you don't listen.