A worker assigned to quick, choreographed entries into extremely high dose-rate locations, classically the steam generator channel head, to install nozzle dams, plug tubes or place equipment. With fields in the tens of rem per hour, a jumper's allowance is used up in minutes, so crews send several jumpers in short turns. Robots and remote tooling take over much of this work, and mock-up rehearsal cuts every second inside.
Nozzle dam install needs four jumpers, two minutes each in the bowl, so rehearse it on the mock-up first.
Also heard as
- steam generator jumper
- SG jumper
Related terms
Bowl
The steam generator channel head, the hemispherical space under the tubesheet where reactor coolant enters and leaves.
Glow boy
Slang for an itinerant contract worker who travels from plant to plant working refuelling outages.
Burned out
Having used up one's allowed dose for the period, so a worker cannot do more radiological work.
High radiation area
A posted area where a person could receive more than 1 mSv (100 mrem) in an hour at 30 cm from a source.