The isotopic analysis code Fixed-energy Response-function Analysis with Multiple efficiency (FRAM) employs user-editable parameter sets to analyze a broad range of sample types. This report presents new parameter files, based upon a new set of plutonium branding ratios, which give more accurate isotope results than the current parameter files that use FRAM.

The FRAM Isotopics Analysis Code has been used to analyze plutonium spectra taken through very thick shielding. Three plutonium sources with 240Pu content of 6.6%, 9.7%, and 16.3% were measured with lead shielding thicknesses ranging from zero to 25.3 mm, in nominal increments of 1.6mm. Multiple spectra were taken for each sample at each shielding level, and the spectra were analyzed using FRAM V3.2. A new parameter set was developed to analyze spectra from zero to 25 mm lead. We will report on the accuracy capabilities of this parameter set.

This two-part manual describes and provides instructions for installing software for Lawrence Livermore National Laboratory's Pu-238 isotopic analysis system built for Westinghouse Hanford's Radioisotope Power Systems Facility. Part 1 contains descriptions of all the subroutines found in the main software program, WHC. ASY238. Also provided in this part are general instructions for modifying a subroutine and specific directions for relinking the WHC. ASY238 program, as well as information on the supporting program PU238. CHNG. Part 2 contains listings of the Pu-238 isotopic analysis system codes. The system uses a large (20% rel. efficiency), coaxial, n-type germanium detector (COAX). Parameter files for the detector have filenames with IS8 extensions. Spectral data files also have WH8 and I01, I02, etc. filename extensions.

We describe the characteristics and features and demonstrate the performance of a new code (FRAM) for determining the isotopic composition of plutonium using gamma-ray spectroscopy. This versatile code can measure an extremely wide range of isotopic compositions and is extremely easy to tailor to specialized measurement conditions. Measurement precision, accuracy, and throughput are significantly improved over previous Los Alamos National Laboratory (LANL) codes. 13 refs., 2 figs., 4 tabs.

This manual describes the use of version 3.2 of the PC/FRAM plutonium isotopic analysis software developed in the Safeguards Science and Technology Group, NE-5, Nonproliferation and International Security Division Los Alamos National Laboratory. The software analyzes the gamma ray spectrum from plutonium-bearing items and determines the isotopic distribution of the plutonium 241Am content and concentration of other isotopes in the item. The software can also determine the isotopic distribution of uranium isotopes in items containing only uranium. The body of this manual descnies the generic version of the code. Special facility-specific enhancements, if they apply, will be described in the appendices. The information in this manual applies equally well to version 3.3, which has been licensed to ORTEC. The software can analyze data that is stored in a file on disk. It understands several storage formats including Canberra's S1OO format, ORTEC'S chn' and SPC' formats, and several ASCII text formats. The software can also control data acquisition using an MCA and then store the results in a file on disk for later analysis or analyze the spectrum directly after the acquisition. The software currently only supports the control of ORTEC MCB'S. Support for Canbema's Genie-2000 Spectroscopy Systems will be added in the future. Support for reading and writing CAM files will also be forthcoming. A versatile parameter fde database structure governs all facets of the data analysis. User editing of the parameter sets allows great flexibility in handling data with different isotopic distributions, interfering isotopes, and different acquisition parameters such as energy calibration, and detector type. This manual is intended for the system supervisor or the local user who is to be the resident expert. Excerpts from this manual may also be appropriate for the system operator who will routinely use the instrument.

DOE/NNSA and IRSN collaborated on a study of gamma-ray instruments and analysis methods used to perform isotopic measurements of special nuclear materials. The two agencies agreed to collaborate on the project in response to inconsistencies that were found in the various versions of software and hardware used to determine the isotopic abundances of uranium and plutonium. IRSN used software developed internally to test the MGA and FRAM isotopic analysis codes for criteria used to stop data acquisition. The stop-criterion test revealed several unusual behaviors in both the MGA and FRAM software codes.