THE INVESTIGATION OF HIGHLY ACTIVATED SAMPLES BY NEUTRON RADIOGRAPHY AT THE SPALLATION SOURCE SINQ

In addition to conventional radiography investigations there is a demand to inspect highly activated samples of spent nuclear fuel or accelerator target materials to detect material defects caused by the strong applied radiation and interaction with the coolant. For this purpose, special facilities and equipment have to be used which are well shielded. Furthermore, neutron radiography detectors have to be found which are insensitive to the radiation emitted by the sample under investigation. The radiography station NEUTRA at PSI can be modified to such a facility to handle highly activated samples under dry conditions and can perform sensitive investigations with high spatial resolution. The paper describes this experimental assembly and shows results from the first cycle of investigations. Several problems (technical and administrative ones) are discussed in some detail.