Operation of a scanning electron microscope in a hot cell

EG and G Idaho, Inc., is using a scanning electron microscope (SEM) and a microanalysis system to examine spent reactor fuel from commercial nuclear power reactors and reactor core debris from the Three Mile Island Unit 2 nuclear power reactor. The SEM is installed in one of four adjacent hot cells at Test Area North of the Idaho National Engineering Laboratory. The hot cell has a 0.914-m (3-ft)-thick concrete walls for shielding and a single leaded glass/mineral oil shield window for viewing the operation. Remote television cameras have also been installed to aid in the operation of the system. The SEM has been modified for remote operation, and additional internal shielding has been added to protect the instrument's x-ray detectors from the ambient background of the spent fuel samples. The basic design concept is for a system that allows the examination of a large number of specimens under fully remote operating conditions. In this way, the upper limit of sample radioactivity can be dependent on the capabilities of the SEM rather than on handling factors