Analyze

What kind of monitoring was used to monitor the amount of exposition to radiation (or, “occupational gamma doses”)? In the film they talk about badges, so I did a little research about what these badges are. I found out, that usually, these badges were TLD (Thermoluminescent dosimeter) badges. Murphy and Goel write on Radiopedia: TLD “is a passive radiation detection device that is used for personal dose monitoring or to measure patient dose”. They work as the following: When radiation falls on TLD, electrons are excited and store energy. After a defined period, for example a few months to a year, the badges are evaluated: The reader is a heater, on getting heated, the excited elevtrons come back to the ground state and emit light in doing so, this light is read by a photomultiplier. Light output is proportional to the radiation exposure (Murphy & Goel).  As Clarence R. Schneider (Health and Safety Representative for Electricians) explains (around min 24), the badges they used went to lab every night, if they weren’t “normal”, the workers were not allowed to work at the process areas the next day, they had to use a blue uniform this day and work in another area. So, this monitoring for me has some similarities with a diagnosis: a sample is sent to a laboratory and the next day you know if you are “normal” and can proceed as every day or not. And if not, then the consequence is that you can't work as usual the next day - that you then also got too much radiation, and were more exposed to the risk of illness, that didn't matter to the workers, Schneider says here. After all, it was their job. Later in the film, around 1h19min, Bill Hoppe, a plant worker, also talks about the badges: he stresses that they were supposed to have badges and other security material, but in fact, they did not have it.

Murphy, A. & Goel, A.: Thermoluminescent dosimeter. Available at https://radiopaedia.org/articles/thermoluminescent-dosimeter, last accessed on 18.05.2021.