0018933 in the-explosion (E), cloud (C) and fallout (FO) are used in the formula: —mle y- - (R” Oro [R?? (Ye - rR”? (¥)] FO y is the fraction of Mo?” left in the cloud and the other quantities are the designated R-values. This formula can be derived by algebraic operations from the definitions of the R-values (see Appendix E), The method seems to be basically valid, but in practice it gives discordant values for y when different nuclides are used in the material balance. Hence it has not been possible to use it as an auxiliary method for calculating the fallout distriea bution, 3.2 DATA RELIABILITY 3.2.1 Cross-Contamination Of Koa Samples. As discussed in Section 2.3.2, a preliminary examination of the samples from Shot Koa, shortly after their receipt at LASL, indicated that they might be badly contaminated with debris from Fir. If this were the case, the fission ratios from the Koa cloud data could not be used for the determination of fallout partition since they would not be representative of the detonation. To investigate the oS- tent of cross-contamination, the Koa samples were analyzed forgshy nuclide formed with a high yield in Fir but notin Koa. summary of the results of this work, 86 Nee a Table 3.8 gives a ee DELETED GAN BRUNO FRE