8. Criticality dosimetry instrumentation

Traditionally, workers exposed to this potential risk wear a criticality dosimeter consisting of activatable targets (ebonite, gold with or without cadmium shielding), added to a conventional gamma measurement. They can also wear a criticality belt comprising several ebonite pellets distributed around the individual, whose sulfur activation measurement can be used to determine the worker's orientation during an accident.

Today, many electronic dosimeters feature a passive diode, enabling neutron dose to be assessed at high doses and dose rates, as in the case of a criticality accident. Dosimeters intended for military use generally include this feature.

In the absence of a dosimeter, a measurement of blood sodium or hair sulfur activation can also be carried out.