A discrete radioactive particle, often less than a millimetre across, typically an activated corrosion product such as cobalt-60 or a fuel fragment. Because all its activity is concentrated in one speck, it can give a high dose to a small patch of skin in hours. Hot particle zones carry extra controls: double protective clothing, frequent frisking, sticky tape checks and quick dose assessment when one is found on a person.
Found a hot particle on his collar reading 40,000 counts, bag the coverall and start a skin dose calc.
Also heard as
- discrete radioactive particle
- DRP
- flea
Related terms
Flea
Slang for a hot particle, a tiny speck of highly radioactive material found on clothing or skin.
Frisking
Slowly scanning a person or object with a contamination probe to find radioactive material before it leaves an area.
Anti-Cs
Anti-contamination clothing: the coveralls, hoods, gloves and overshoes worn to keep contamination off workers.
Equivalent dose
Absorbed dose to an organ multiplied by a weighting factor for the type of radiation, measured in sieverts.
PCE
Personnel contamination event: contamination found on a worker's skin or personal clothing above a set threshold.