SECRET CHAPTER 1 INTRODUCTION 1.2 O89F The objectives of Project 2.66 were to determine: 1. The variations in chemical and radiochemical composition of 2. The chemical and radiochemical nature of liquid fallout and solid fallout with particle size, zero-point environment, and time and distence of collection. base surge, if formed. 3. The manner in which gross decay rates are affected by variations in radiochemical composition. 1.1.1 Purpose The purpose of obtaining these data was for use in studying basic problems of fallout phenomensloyy. The ultimate objective of this and +imilar work is to ebtain data which may be used to develop a theory for the prediction of the military effects of operaticnal nuclear weapons under specific conditions. Data obtained to meet the first objective may be used to aid_in the development of a model of fireball dynamics in relation to particle formation, Liquid fallout was also studied to gain further insight into the history of the fallcut materiel after its formation, and for documentation of internal radiation hazards. An investigation was carried out on the relation between decay rate and radiochemical composition because it appeared that 1t might be applicable to the problem of predicting the decay characteristics of fallout material from any operational detonation. 3 SECRET RESTRICTED DATA