Year
1994
Abstract
Two Canberra-built passive-active 252Cf shufflers of Los Alamos hardware and software design have been installed and are presently undergoing calibration and certification at Los Alamos National Laboratory. These instruments fulfill important safeguards and accountability measurement requirements for special nuclear material in matrices too dense or otherwise not appropriate for typical gamma-ray techniques. The ability of the shuffler to obtain precise assays under conditions of intense passive emissions of neutrons and gamma rays is a valuable asset in plant environments. This paper reports on the procurement process and the various steps involved in the installation of two shufflers at Los Alamos, one at the Chemical Metallurgical Research (CMR) Building Waste Assay Facility at TA-3 and the other at the PF-4 Plutonium Facility at TA-55. Details are given on the certification procedure including the development of standards, various expected matrices, and calibration. Some safety issues are addressed, and some preliminary performance characteristics are presented based on measured background rates in the plant environments.