ments, so long as the release ratio is reasonably uniform. 

 From the data in Table 1, the mean ratio, month-by-month , 

 from Millstone No. 1 was 0.43, and weighted by the activi- 

 ties released 0.54; from Table 2, the ratios from Mill- 

 stone No. 2 were, respectively, 0.50 and 0.60. Since Mill- 

 stone No. 1 during this interval, put out about four times 

 as much total radio-Cs as did Millstone No. 2, and the 

 ratios, 134(;s to 137cs, are so close, it would be possible 

 to use the change in this ratio, in reasonably well- 

 isolated samples, as a dating tool. 



Much the same conclusion is supported, for Maine Yankee, 

 by the data in Table 3, although the amounts of radio-Cs 

 discharged are much lower, so that its use as a tracer may 

 be expected to be somewhat more difficult. 



238p^j.239,240 



Pu: 



vered t 

 have be 

 reactor 

 fal 1 out 

 the Mil 

 reactor 

 substan 

 238PU t 

 compare 

 only to 

 tri buti 



increme 

 in e n V i 

 238Pu:2 



the 

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, ver 



1 ston 



effl 

 tial 

 239 

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abou 

 on in 

 nts 

 ronme 

 39,24 



hi gher 

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 know of 



sus the 

 e or Ma 



uent Pu 

 di f fere 

 ,240Pu: 

 the fal 

 t 0.10 



the no 

 f react 

 ntal sa 

 OPu rat 



he amo 



latit 



pared 



: abo 



nanno 



i n e Y a 



in th 



nee in 



rang 



1 out m 



even a 



rthern 



or-rel 

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io . 



unts 

 udes 



to tho 

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curies 

 nkee r 



is sit 

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eased 

 by the 



f Pu 

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 Ci Pu 



per 

 eacto 

 uatio 

 harac 

 om ab 



abou 

 hei gh 

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effe 



that ha 

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1 eased 

 per km 



month r 

 rs . Tr 

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 t e r i s t i 

 out 1 t 

 t 0.035 

 t of th 

 Even 

 n thus 

 ct they 



ve bee 

 rn hem 

 from a 

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el ease 

 a c i n g 



ded by 

 c rati 

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 , w h i c 

 e SNAP 



qui te 

 be ide 



have 



n deli- 

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uch as 5 , 

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9A con- 



smal 1 



n t i f i e d 

 on the 



241 



Am : This nuclide in fallout has originated almost en- 



ti rely from decay of its parent 241pu. At the ratios so 

 far observed of 241pu to 239,240pu in test debris, the in- 

 growth of 24lAm is not predicted to produce ratios above 

 0.30 24lAm to 239,240Pu until about 1980. Of course in geo- 

 chemical settings where Am is separated from Pu, this 

 ratio changes, and we have seen it as high as 1 in sedi- 

 ments from special situations. In general, however, re- 

 actor waste 24lAm can be at least partly differentiated 

 from fallout 24lAm by its ratio to 239,240pu. 



14 



