I worked in non nuclear power plants.
How one of our employees found the freedom of weed did not fit. He and a newer employee were assigned to deliver test equipment to a work site for the next day,
Sunday. Weedy semi stopped at a traffic light, behind a late model car, released the brake while still moving, and bumped the car ahead. Driver ahead was annoyed, but pulled up a couple of feet. Weedy just giggled at the first bump, and continued no foot on brake, and the auto transmission had enough throttle supplied to run up and bump again.
The offended driver got out, and came back to our truck, the brand new assistant set the parking brake, picked up the mike, and softly said " Truck 123, and the location", then "send an officer". The dispatcher understood from the softness that there was a serious problem, and merely responded OK. Next, the newbie turned off the ignition and removed the key.
Two police cars arrived, took a short statement from the offended driver, handcuffed Mr. giggles, asked if the newbie could drive the truck and he said "No, but I can move it to the curb, and call our dispatcher for another driver".
This took place in the first 2 hours of the shift, and Weedy was converted to AWOL. Sunday he was again AWOL, as he had no money for posting bail.
Monday, he had his hearing, still no bail, so stayed another day in detention.
Tuesday, he was fired for 3 consecutive days AWOL.
We did not have a suitable test for weed back then, and had been dealing with bad days, with the senior employee trying to keep him away from danger About half the time, he was floating to some degree at work.
Weedy in a nuclear or even a fossil fuel plant could simply bump into a control switch, and knock the plant off line, and possibly do millions of dollars of damage.
The nearly brand new guy off the street received a very complimentary letter in his personnel jacket, and proved to be an excellent employee.
Weed is a bigger issue than the users are willing to admit. They are worse that drunks at determining if they are too impaired to drive, etcetera.
One of my assistants had 3 dui arrests for weed, he felt he was no risk, since he drove very slowly. The cops nabbed him for 10 MPH on the Washington Beltway, slowly creeping home after a party with similarly inclined friends. He concluded that driving faster would end the stops, but he hit a 3 foot diameter oak, at about 45 MPH, in his VW Jetta.
That solved the question of how we were going to get rid of him.