The
RSO provided a report for the failure of a source position indicator on a SABIA, Model XC-series-25 materials analyzer (device per NR-1195-D-103-S) located at Cyprus Creek Mine in
Indiana. During a scheduled NRC inspection on 01/11/06 of the shutter for the radioactive source, with the shutter indicating being in the locked out (OFF) position, the source was actually in the open position and the shutter lever appeared to be 180 degrees out of position. During an internal inspection by SABIA on 01/14/06, everything appeared to be in good working order. It was determined that prior to the NRC inspection on 01/11/06, a contractor who was performing a wipe survey of the device retracted the source, but rather than moving the source lever as indicated by the arrows, moved the lever the shortest distance to OFF. This action forced set screws to slip and move the handle to OFF but the sources remained active (ON).
In this instance, because the NRC inspector arrived soon after the lever position had been changed, no maintenance was done on the conveyor inside the analyzer while the indication was wrong and no one received any radiation dose resulting from this problem. The unit was repaired by removing the handle and replacing it in the proper position.
SABIA will prepare mechanical stops to put on all analyzers that will prevent the source handle from being moved in the wrong direction and will install them as analyzers are routinely serviced.
This information represents an interim report, and a final report, together with corrective actions, will be forwarded within 30 days.