Annual Report for 2010/11 and Forward Programme - Sellafield Ltd

SSEM/2011/4730 June 2011mentioned in the section above, can be seen in the Evolution 2 data compared with Synergy.The larger data set for Synergy (i.e. 454 particles) dominates the distribution compared toEvolution 2 (i.e. 60 particles).Log Am241 Activity Histiogram of Separate Evolution 2 and Synergy Data706050Frequency4030201003 3.1 3.2 3.3 3.4 3.5 3.6 3.7 3.8 3.9 4 4.1 4.2 4.3 4.4 4.5 4.6 4.7 4.8 4.9 5 5.1 5.2 5.3 5.4 5.5 5.6 5.7 5.8 5.9 6Log to base 10 of Am241 ActivityEvolutionSynergyFigure 3.16. Separate Evolution 2 and Synergy 241 Am Activity Histogram.Log Am241 Activity Histogram706050Frequency4030201003.00E+003.10E+003.20E+003.30E+003.40E+003.50E+003.60E+003.70E+003.80E+003.90E+004.00E+004.10E+004.20E+004.30E+00Log to base 10 of Am241 Activity4.40E+004.50E+004.60E+004.70E+004.80E+004.90E+005.00E+005.10E+005.20E+005.30E+005.40E+005.50E+005.60E+005.70E+005.80E+005.90E+006.00E+00Figure 3.17. Combined Evolution 2 and Synergy 241 Am Activity Histogram.The plutonium isotope analysis for alpha-rich particles shows a similar log normal distribution(Figure 3.18 and Figure 3.19. With less Plutonium data available compared to 241 Am theshape of the distribution is not as well defined as for 241 Am. That is, 514 particles wereincluded in the 241 Am activity plot compared to 109 for the 239 Pu activity plot and 84 for the238 Pu activity plot. In addition to the effect of the lower numbers of Plutonium results, theiranalysis also have moderately large uncertainties compare to 241 Am analysis.© Nuclear Decommissioning Authority 2011. 43