Applications of a Transportable Spent-Fuel Measurement System

A portable tool for making measurements on irradiated fuel has been developed to where in-plant installations having a 1-2% measurement uncertainty of relative exposure are feasible. The measurement uses a passive gross neutron signal and data from a gross gamma measurement as a consistency check of the neutron result and the operators declaration of cooling time. The uncertainties are about the same as those obtained using HRG techniques without the instrumentation being as obtrusive. The battery-operated microprocessorbased electronics package used with the irradiated fuel measurement system can also be used with single channel pulse counting detectors for other applications. This feature together with the large dynamic range of its current-mode ion chamber channel makes ION-I a good building block to be used in emergencies with an arsenal of detectors at a variety of nuclear plants.