Re-measured uranium branching ratios and their impact on removing biases from MGAU analyses
Biases in MGAU analyses first observed in FSU Gosatomnadzor inspection and subsequently identified in more detail by measurements at the Moscow Kurchatov Institute have forced a new look at the code's analysis assumptions. We have used uranium gamma-ray calibration standards from the National Bureau of Standards and standards from the New Brunswick Laboratory to investigate MGAU analysis biases. The 200g uranium standards which cover the uranium enrichments ranging from 0.3% to 93% were used to collect more than 500 gamma-ray spectra for this study. The experimental arrangement used a LEPS Ge detector with various source-detector configurations and absorbers. Two independent versions of the MGAU code, which we currently employ in our laboratory, confirm the biases noted in a developing variety of FSU inspection results and in the careful Kurchatov study. In this paper, we will discuss the MGAU methodology and use 250 spectra at a fixed geometry without absorbers to obtain new branching ratios for the critical 100-keV region gamma rays. We show that modifying the branching ratios removes a significant component of the observed biases.
- Research Organization:
- Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States)
- Sponsoring Organization:
- USDOE Office of Defense Programs (DP) (US)
- DOE Contract Number:
- W-7405-ENG-48
- OSTI ID:
- 14672
- Report Number(s):
- UCRL-JC-135774; GD0604020; GD0604020; TRN: AH200129%%435
- Resource Relation:
- Conference: 6th International Conference on Facility Operations, Safeguards Interface, Jackson Hole, WY (US), 09/20/1999--09/24/1999; Other Information: PBD: 17 Sep 1999
- Country of Publication:
- United States
- Language:
- English
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