I must be wrong about the placard then.
I am going by memory from 35 years ago of what dad told me.
He never hauled nuclear waste. He hauled other hazardous chemicals.
Every once in awhile though he would haul some household item. Like Palmolive dish detergent. He brought the trailer home before taking it back to the terminal to get cleaned out. We had multiple buckets of dish detergent.
Another time he hauled raw sugar. There was still a little left in the bottom of the tanker in the tubes. We filled up a couple of brand new Rubbermaid trash cans with sugar. Gave it to all our friends.
He mostly stayed east of the Mississippi. Although I remember once hauling a tanker of jet fuel out to White Sands Air Force base in NM. Probably the tanker coming on the railcar was late shipping.
Dad was an owner operator. He was leased to drive for Chemical Leaman out of PA. We lived south of Buffalo.
One of the more frequent and better paying loads was hauling rocket propellant to Anniston, AL. Where they made the ballistic missiles.
It would have been nice to have a couple buckets of jet fuel a round, but I would skip the rocket fuel.
That stuff is scary. Whatever they paid him, it wasn’t enough.