Cf-252 Shuffler for Waste Assays and Safeguards Applications

摘要

The accurate determination of uranium and plutonium content in both nuclear waste andsafeguards fields is very important. The measurement field is quite wide and often quite difficultto apply alpha spectrometry, gamma ray spectrometry or mass spectroscopy. Manynondestructive assay (NDA) techniques use neutron interrogation methods because of the highpenetrability and the selective sensitivity of neutrons. The Cf-252 Shuffler is able to identifysmall quantities of uranium or other fissile material in large and/or dense waste drums.In this paper we report on a first Cf-252 Shuffler that uses software running in Windows XP anda Programmable Logic Controller. The system was developed at Canberra and is based on theLos Alamos National Laboratory (LANL) Cf-252 Shuffler design. The shuffler contains sixtyfour10-atm He-3 tubes configured in eight banks and two 4-atm He-3 tubes used as fluxmonitors. The neutron interrogation is realized using a 600 μg source. The control mechanism isa Programmable Logic Controller (PLC). Both communications with the PLC and dataacquisition are performed through Canberra’s NDA 2000 software running on the Windows XPoperating system. The shuffler data acquisition system uses the latest shift register electronics;the JSR-15, the JSB-96 and two Multiport II Multi-channel Analyzers. In this work we describethe system and algorithms utilized to convert the response of the system into fissile masses.Preliminary results using Uranium NBL-CRM-969 standards are presented.