Detection of special nuclear materials (SNM) using passive and pulsed neutron source based active coincidence methods

Detection of fissile and fertile materials and their accountability is important for nuclear safeguards. This paper reports detection of U-238 and U-235 in the same experimental setup using passive and pulsed neutron source based active coincidence methods respectively. The coincidence analysis has been carried out using a time stamp data acquisition system. Furthermore, the paper reports the fast ever detection of U-235 using D-T pulsed neutron source based active coincidence method along with time stamp data acquisition system. In this study, 142.86 gm U-238 and 1 gm U-235 have been detected successfully using passive and pulsed neutron source based active coincidence methods with 6000 s and 400 s time stamp data respectively acquired using only eight He-3 detectors of 45 cm active length. Furthermore, the present research methodology can be extended for the detection of Plutonium. This work will also be of importance towards detection of small quantity of SNM in cellulose waste from nuclear material processing facilities.