A New Fallout Prediction Model

Abstract

The standard method for the calculation of nuclear weapon fallout radiation doses and dose rates in operational type studies for the last 20 yr has been the computer algorithm known as WSEG-10. WSEG-10 uses empirical functions rather than numerical analyses and computes fallout dose (rates) in seconds or less on modern computers. WSEG-10 has long been criticized for its inability to allow for variations in the activity-particle size distribution of the fallout, for its inability to account for fractionation and for the absence of realistic settling rates. At the other end of the scale, the Defense Land Fallout Information Code, DELFIC, is currently used for research work and as a comparison standard. DELFIC produces fallout footprints on the ground by numerical integration, employing discrete cells in space, time and particle size. A new fallout prediction method is presented here which, unlike WSEG-10, does allow variations in activity with particle size, does account for fractionation and does model variable settling rates. This new model, like WSEG-10 but unlike DELFIC, computes in seconds or less. Some results are presented and compared to DELFIC and to WSEG results. Additionally, this new model will treat the far-field problem of interest in a massive strategic attack which cannot be easily done using DELFIC.

Identification Method of Source Term Parameters of Nuclear Explosion Based on GA and PSO for Lagrange-Gaussian Puff Model

“…However, this error can interfere with the source term parameter identification process. The next study will try to perform an optimization search experiment using algorithms such as GA and PSO in combination with several well-established models such as DELFIC [53] or WSEG [54] so as to analyze the impact of each prediction model error on the source term parameter identification accuracy. 2.…”

User Guide for the Air Force Nuclear Weapons Center Dust Cloud Calculator V.1.0

“…The dust cloud model uses the Air Force Institute of Technology (AFIT) dust cloud and fallout model. (Bridgman, 1982, Hopkins, 1984, Conners, 1985 The model is relatively easy to implement, and has been validated for use in Air Force survivability studies. (Palmer, 1987) The Air Force adapted the AFIT dust cloud model into the Residual Dust and Radiation Model (REDRAM), which was developed by Palmer at the AF Nuclear Criteria Group Secretariat (NCGS), by Brown at the Aeronautical Systems Division, and by Hopkins at the Air Force Center for Studies and Analysis.…”

“…The particle fall velocities are calculated using Stokes Law, with corrections for the aerodynamic drag of larger particles using a method developed by McDonald and Davies. (Bridgman, 1982) The rest of this user guide explains how to install and use the Dust Cloud Calculator software.…”

Calculation of probability of an aircraft meeting nuclear clouds

“…The assumption of non-overlapping clouds is one that may not be realistic in a real world situation. [8,9] In order to calculate the probability of intersection with overlapping clouds, data is needed regarding the area of overlap between each pair of clouds, Cjk; j, k = 1, 2, ... , n. The equation for Pi then becomes "n C . _ "n-I"n C .…”