SUMMARY

Since the advent of nuclear weapons in the early 1940's, there has been much research and speculation on the devastating effects that these weapons provide. From the race to build bigger and more deadly weapons, to the creation of safeguards to prevent their proliferation; nuclear weapons have been at the forefront of modern deterrence and international decision calculus.
Nuclear fallout are the particulates that are created following the detonation of a nuclear weapon. They can range in size from a few centimeters all the way down to several microns. The composition of fallout depends on the environment that the nuclear weapon is detonated in. This environment does not just refer to the physical environment of ground zero, such as the soil composition and atmospheric conditions, but as well as the HOB of the weapon, the composition of the fuel of the weapon, and the type of weapon.
Each nuclear modeling code HPAC, DELFIC, KDFOC3, and HOTSPOT have their own utility in developing a post blast fallout scenario. These codes however, do have some assumptions that reduce the effectiveness of truly displaying a post blast environment, such as they assume a flat plain devoid of terrain which in real life will influence the dispersion of fallout, next they assume an idealized base soil composition for either silica or calcerous based soil compositions, and finally they have set fallout PSD based on initial conditions.
By using both historic test data to validate the source models from we are able to better represent the particle size, morphometry, and isotopics. With this information a realistic particle source term can be created in order to be used for further analysis and modeling in dosimetry. Each particle source term depends on the initial conditions of the weapon system and location of use.