I am not a nuclear engineer, so can someone explain the safety risks in the event of a car accident?
Worst case scenario if you literally ground the car into dust you'd release perhaps ten milligrams of nuclear waste. Why you'd grind an entire car into dust is a mystery. I suppose fed into a compactor and melted and recycled without removing the probably mostly unused and valuable fissionables is possible.
So in an accident would you rather have 10 mg of waste, or 30 gallons of hyperflammable gasoline, or 1000 Kg of lithium batteries, or ...
You're probably better off in an accident with this.
And yet, it's still in pretty much every car. So I think we can probably handle some thorium, too.
On the other hand, 30 gallons of gasoline is in a cheap tank made out of cookie cutter metal so it tears open in a minor crash and there's a puddle of it underneath the seat you're strapped into. And it burns. Really well. So a giant pool of it is currently on fire, underneath your feet. Whoops. Unfortunately this happens fairly often.
The lithium battery is more complicated to model. They burn, really well, but if properly vented they can't explode. So its kind of like driving a truck with 1000 pounds of grilling charcoal in the back... if it ignites, and you just sit there, you'll eventually be grilled like a bratwurst, but its going to take a heck of a long time, so unless you're alone and unconscious in abandoned distant wilderness for 15 minutes you're OK.