The application of solid state nuclear track detectors in nuclear safeguards

The application of solid state nuclear track detectors (SSTD) for the determination of the burn-up of spent reactor fuel elements has been investigated. The results of the SSTD's were compared with two active methods such as fuel element scanning with a fission chamber and an ionization chamber. In addition the gamma profile was measured with thermoluminescence dosimeters. The SSTD using Makrofol KG were exposed as a sandwich with a 93% enriched uranium foil to detect spontaneous neutrons emitted from transuranic elements. Through a (n,f)-reaction the neutron density was evaluated by counting the fission tracks with a jumping spark counter. Two TRIGA research reactor fuel elements, one with low the other one with high burn-up were investigated by this method and the SSTD results almost conformed to the other three methods mentioned above. Finally, this method has been slightly modified to be applicable also for power reactor fuel. (author)