Revision of the DELFIC Particle Activity Module

Hooper, David A. ; Jodoin, Vincent J.

Oak Ridge National Laboratory

关键词: Fission Yield;    Isotopes;    Decay;    Actinides;    Fractionation;   

DOI  :  10.2172/1028737
RP-ID  :  ORNL/TM-2010/220
RP-ID  :  DE-AC05-00OR22725
RP-ID  :  1028737

美国|英语

来源: UNT Digital Library

【 摘 要 】

The Defense Land Fallout Interpretive Code (DELFIC) was originally released in 1968 as a tool for modeling fallout patterns and for predicting exposure rates. Despite the continual advancement of knowledge of fission yields, decay behavior of fission products, and biological dosimetry, the decay data and logic of DELFIC have remained mostly unchanged since inception. Additionally, previous code revisions caused a loss of conservation of radioactive nuclides. In this report, a new revision of the decay database and the Particle Activity Module is introduced and explained. The database upgrades discussed are replacement of the fission yields with ENDF/B-VII data as formatted in the Oak Ridge Isotope Generation (ORIGEN) code, revised decay constants, revised exposure rate multipliers, revised decay modes and branching ratios, and revised boiling point data. Included decay logic upgrades represent a correction of a flaw in the treatment of the fission yields, extension of the logic to include more complex decay modes, conservation of nuclides (including stable nuclides) at all times, and conversion of key variables to double precision for nuclide conservation. Finally, recommended future work is discussed with an emphasis on completion of the overall radiation physics upgrade, particularly for dosimetry, induced activity, decay of the actinides, and fractionation.