Abstract: Apparatus for decontaminating radioactive components comprising an attachment mechanism for completely suspending the apparatus from the tube sheet of a nuclear steam generator, a first drive mechanism for moving the apparatus in a first direction, a second drive mechanism for pivoting the apparatus in a second direction, and a third drive mechanism for moving the apparatus in a third independent direction. The apparatus also comprises a dual nozzle arrangement attached to the third drive mechanism for directing a water-grit mixture toward the component to be decontaminated. The apparatus provides a mechanism for remotely decontaminating the channel head of a nuclear steam generator so as to allow working personnel to enter therein.

Abstract: A probe positioner capable of being supported from a tube sheet of a nuclear steam generator for positioning a probe in relationship to the tube sheet of the nuclear steam generator comprises a locking mechanism for locking the probe positioner in the tube sheet and a plurality of rotatable arms for positioning the probe. The probe positioner also comprises quick disconnect motors for rotating the arms of the probe positioner relative to each other.

Abstract: Two abutting members are locked together by reaming a hole entirely through one member and at least partly through the other, machining a circular groove in each through hole just below the surface of the member, press fitting a dowel pin having a thin wall extension on at least one end thereof into the hole in both members, a thin wall extension extending into each through hole, crimping or snapping the thin wall extension into the grooves to positively lock the dowel pin in place and, if necessary, tack welding the end of the thin-wall extension in place.