CHAPTER 3 CHEMICAL MEASUREMENTS The significant properties which determine the relative thermo- c stability of a contaminated system ares (1) the composition of the fallout material, (2) the phase distribution of the various constitvents, and (3) the chemical and physical state of certain elements. Most of these properties of the fallout were found to be determined by or dependent on the location of the point of detonation. Reef shots pro- duced largely coral-derived material; barge shots produced largely sea water derived material. The distribution of the radioactive elements and the stable or carrier material between the liquid and solid phases and further between colloical and ionic fractions gives information on chemical and physical states of components known to be important contaa- dnation-decontamination parameters. In addition, the oxidation states of certain radioactive elements determines their chemical behavior in the fallout mixture during the period of contamination. Thus the thermodynamic environment in which radioactive species of the fallout occur influences their contamination potential to the extent of controlling it. Chemical measurements of the significant properties were made on samples collected from Shots 1,2,3, and 4. The characterization of the fallout samples consisted of: (1) measuring the total activity of each sample with a survey meter; (2) determining the total quantities of solids and liquids in them; (3) measuring the pH of the liquid phase of those samples which had suffi- cient liquid; (4) determining the total beta and gamma activities in each sample; 65 ) fractionating representative samples into solid, colloidal, sud ionic constituents and measuring the radioactive characterietics of each fraction; and (6) analyses for the major and minor constituent elements in fallout samples and in several samples of sea water and coral. The samples received for analysis were not always representative of the actual fallout owing to the collection of rain water, sea water spray, and extraneous coral and orgenic material in the open collectors, Never- theless, from the analytical data an estinate of the composition of the actual fallout has been made by subtracting the extraneous sea water and coral constituents found in the diluted samples. 27