Revealing smuggled nuclear material covered by a legitimate radioisotope shipment using CdTe-based gamma-ray spectrometry

Illicit trade of nuclear materials (NM) represents a serious challenge to radiation monitoring upon scenarios, when legitimate radioisotope shipments are used to obscure the weak radiation of NM. Planar and hemispherical Cd(Zn)Te detectors with a portable mini-multichannel analyzer were proven to be suitable, in measuring times of 10 min order, for revealing the presence of low-enriched or natural U-bearing reactor fuel pellets in amounts of kg order, placed beside transport containers of lead or depleted uranium, which contain high activity 60Co (10 GBq range) or 192Ir (TBq range) radioisotope sources. Such a hand-held or portable device may help authorities combating illicit trafficking of nuclear materials.