ADDENDUM TO TECH NOTE 2.2: DETERMINATION OF THE PLUTONIUM TO AMERICIUM RATIO IN SOIL SAMPLES FROM ISLAND VERA DOE/ERSP TECH NOTE NO. 2.2-A DATED: 9 February 1978 AUTHOR: J. Giacomini, DRI To determine a ratio for total transuranies (TRU) to 241Am certain assumptions were made. One assumption is that the true ratio is constant at each value of 24l4m and that a plot of TRU against 2414m is a straight line through the origin. The second assumption states that the variance. of TRU increases proportionally to 2414m as 24lam increases. Both of these assumptions are met by the data from this island. Reference "Ratio Estimation Techniques in the Analysis of Environmental Transuranic Data" by Pamela Doctor and Richard Gilbert. Data collected at four sample locations (two composites) were used in computing the mean ratio and associated error, The Vera data has a mean ratio of 2.51 with a standard deviation of 0.22;* these values were used in estimating TRU and upper bounds. "A" Sample "B" Sample Location TRU 241.4m TRU 241am 2-W-2 4-B-0 5-E-2 7-B-0 10.23 9.31 13.21 12.68 3.31 3.41 5.04 4.87 16.96 5.7 11.43 11.3 7.49 2.46 4.90 4.62 DETERMINATION OF THE TOTAL TRANSURANICS TO AMERICIUM RATIO IN SOIL SAMPLES FROM ISLAND OLIVE DOE/ERSP TECH NOTENO. 2.3 DATED: 17 January 1978 AUTHOR: M. Barnes, DRI Determination of one mean ratio for Olive was made including 238, 239, 240py and 241Am, Laboratory results of 22 samples taken at four locations were used to compute a mean ratio. Ratios for 0, 10, and 20em were from the same population, so all depths were included when computing the mean. The rangein values is from 2.01 to 3.72. The simple mean** is 2.74 and the standard deviation 0.46; these values were used to derive total transuranics estimates and upper bounds. Location No. 18-S-2 10-S-2 8-N-6 2-N-2 Depth, em 0 2.97 3.48 2.70 2.31 10 2.96 2.61 2.97 2.72 2.49 2.40 3.45 2.01 _ 20 2.88 2.59 3.19 2.01 2.17 _ 2.47 2.55 2.59 _ 3.07 3.72 *Due to a programming error, the standard deviation reported here is overestimated. **This method of estimating the ratio and error was later replaced by a method based on more accurate assumptions as described in Tech Note 2.2-A. B-2-12