Radiation
Dr. Desrosiers gave a great talk on determining radiation dose from bone and tooth samples today. In addition to some horrifying stories about people doing stuff like standing next to Cobalt-60 samples and dying horrible, agonizing deaths as a consequence, there was one hilarious near-accident that occured just down the road from where I am now.
In Gaithersburg there's a Teflon reprocessing facility. Before Teflon can be melted down and recycled, it has to be made brittle, and the only way to do that is to zap it with enormous amounts of radiation. So there a linear accelerator, installed vertically, in this building, with the business end of the accelerator pointed strait down. Surrounding this room is a concrete and lead walled maze, with the control room outside, and the whole works is filled with uncountable safety overrides. Well, one day there was a bad storm which knocked a hole in the roof, so the guys at the reactor called a roof repair company, who said a repairman would show up between nine and noon the next day. To no one's surprise, noon came and went, and no repair guy showed up. So the workers shrugged, turned the accelerator on, and went back to work.
Half an hour later, the roof repair man arrives. But instead of heading in to announce his arrival, he just sets up his ladder and heads out onto the roof. He locates the hole, and decides to look around inside. Well, it was big enough to fit him, so the repairman climbs all the way in the hole. Having had a good look, he decides to head inside and tell the accelerator workers that he was there. But does he climb back down the side of the building? Nope. He sees a ladder inside the hole, and climbs down the ladder. Now, the hole was right next to the accelerator tower, and the ladder was inside the tower, with nothing but a thin wall of concrete between him and 200,000 grays of radioactive death (5 grays is 50% lethal). This isn't get-cancer-in-twenty-years-and-die kind of radiation, this is closer to the instant vaporization end of the scale. Totally oblivious to the impending doom, he happily climbs the ladder, and ends up inside the same room as the end of the electron beam. At this point, he had two choices, turn right, and strait into the (invisible) death ray, or left, and out. Fortunately, he turned left, and shortly tripped one of the safety devices, which scared the living daylights out of the technicians, since there was a loud "BANG!" as the accelerator turned off and lead doors opened, and out of the reaction chamber strode a totally unharmed man.
The electron beam was sufficiently collimated that the repairman recieved only a trivial dose as a result of his adventure.
In Gaithersburg there's a Teflon reprocessing facility. Before Teflon can be melted down and recycled, it has to be made brittle, and the only way to do that is to zap it with enormous amounts of radiation. So there a linear accelerator, installed vertically, in this building, with the business end of the accelerator pointed strait down. Surrounding this room is a concrete and lead walled maze, with the control room outside, and the whole works is filled with uncountable safety overrides. Well, one day there was a bad storm which knocked a hole in the roof, so the guys at the reactor called a roof repair company, who said a repairman would show up between nine and noon the next day. To no one's surprise, noon came and went, and no repair guy showed up. So the workers shrugged, turned the accelerator on, and went back to work.
Half an hour later, the roof repair man arrives. But instead of heading in to announce his arrival, he just sets up his ladder and heads out onto the roof. He locates the hole, and decides to look around inside. Well, it was big enough to fit him, so the repairman climbs all the way in the hole. Having had a good look, he decides to head inside and tell the accelerator workers that he was there. But does he climb back down the side of the building? Nope. He sees a ladder inside the hole, and climbs down the ladder. Now, the hole was right next to the accelerator tower, and the ladder was inside the tower, with nothing but a thin wall of concrete between him and 200,000 grays of radioactive death (5 grays is 50% lethal). This isn't get-cancer-in-twenty-years-and-die kind of radiation, this is closer to the instant vaporization end of the scale. Totally oblivious to the impending doom, he happily climbs the ladder, and ends up inside the same room as the end of the electron beam. At this point, he had two choices, turn right, and strait into the (invisible) death ray, or left, and out. Fortunately, he turned left, and shortly tripped one of the safety devices, which scared the living daylights out of the technicians, since there was a loud "BANG!" as the accelerator turned off and lead doors opened, and out of the reaction chamber strode a totally unharmed man.
The electron beam was sufficiently collimated that the repairman recieved only a trivial dose as a result of his adventure.