Are you learned in radiation protection? Huge difference between "inhalation" and ingestion. Assuming the S/G worker was in compliance with the RWP, then "only a face shield and paper suit" had been evaluated and determined proper dress for the work. Chance of a DRP winding up in the S/G channel head due to a leak on the closure head is unlikely although possible. The millions of gallons of RCS that pass thru the area is more likely the cause. This site is not a good place to go on a fishing expedition as many inhabitants actually know what they are talking about.