Neutron Multiplicity Assay of Impure Materials Using Four Different Neutron Counters*

Year
1998
Author(s)
D.G. Langner - Los Alamos National Laboratory
J.E. Stewart - Los Alarnos National Laboratory
T.R. Wenz - Los Alamos National Laboratory
M. S. Krick - Los Alamos National Laboratory
Abstract
During an advanced International Atomic Energy Agency (IAEA) inspector training course given at Los Alamos in November 1997, there was an opportunity for a comparison study of various neutron detectors to quantify measurement performance using pure and impure plutonium oxide and mixed uranium-plutonium oxide (MOX) items. Because of the cost of counters designed specifically for multiplicity analysis, we wanted to explore the limits of other, less costly and less efficient detectors. This paper presents and compares neutron coincidence and multiplicity assay performance for five detectors, which vary widely in detection efficiency. Eight pure plutonium oxide and twelve impure plutonium oxide and MOX working standards were used in the study.