ony a LL ate: SFE PRS - LTE ARERR RITENUE ES a, ‘ 5.3 VARTATION OF RADIOCHEMICAL SOMPOSITIGN WITH PARTICLE SIZ, * ZERO. FOINT PRVTPONMENT, AND TIME 4° DISTANCE OF COLLECTION The variation of radiochemical composition with particle size is illustrated graphically in Fig. 5.1 - 5.7. The activity concentration decreases regularly with particle size to about 50 3 above 50 p the situation 4s somewhat obscure. Figs. 5.1, 5.3, and 5.4 exhibit a sharp discontinuity at 50 p. It is possible to draw lines throurh the voints in the other figures in such a manner as to indicate discontinuities, rather than the smooth curves shown. It has been of agglomerates by the Poller analyzer, as discussed in the preceding section.. Thedifferences between the various curves detail the fractionas tion indicated by the R-values (Tables 4.3). Only the relationships between the different curves can be regarded as significant, howevey because of the uncertainty in the per cent active particles mentioned in the preceding ecetion. In another reportzi/ the authors have used certain assumptions regarding cat5 to obtain per cent active varticles figures. Correction of the data by these figures leads to curves whose slopes have been interpreted to give an insight into the mechenism . of particle formation. eeTy a ee pc/mg i ion ole it ie Ft! postulated20/ that this discontinuity is related to the breaking up ‘ 2 Fig. 5.1 s 2 20 Eo] DIAMETER IN MICRONS 00 200 $00 Activity Concentration of sr89 vs Particle Size 40 SECRET ~ RESTRICTED DATA