Demonstration of a Possible In-Situ Monitoring System for Large Storage Facilities for the Trilateral Initiative

In a large storage facility where items are placed in difficult-to-access locations, the ability to verify that items placed in the facility have remained there is a challenging task. It is desirable to perform measurements that can quickly screen large fractions of the inventory without removing items from their storage locations. Such a system might measure gross gamma-ray and neutron emissions from a storage location and compare the results with previous measurements to give a qualitative assurance that the items in the storage location have not changed. Under the auspices of the Trilateral Initiative Technical Workshop at the Joint Research Center in Ispra, Italy, we have demonstrated a prototype monitoring system that can quickly provide confidence that items placed in storage have remained in storage, without revealing sensitive information about the items themselves. The prototype system consisted of a CZT detector and a small 3He tube placed on a motorized winch that could reproducibly be moved horizontally past an array of storage drums. A profile of the gamma-ray and neutron signals was measured as a function of the position of the detectors with respect to the drum locations and then compared with previous profile measurements made on the same array. By comparing the profiles, a qualitative assessment could quickly be made as to whether the items in the storage drum array had changed between the measurements.