[en] A movable work station includes travelling hoist-supported tools and a radiation-shielded enclosure or gondola that may be moved vertically or rotated. The enclosure is divided and accommodates four upright workers in facing pairs at opposite sides of a clearanceway observable and accessible from the gondola interior via lead glass windows and hand holes. The work station is particularly suitable for personnel involved in tube bundle replacement tasks performed within the shell of a nuclear power plant steam generator