107? 1 2 4 6 810 }-—_—_—— HOURS 201 +}< 2 4 6 810 20 DAYS 40 60 10% 100 200 1 ele 2 4 TIME AFTER FISSION Fig. 10—Gross disintegration-rate decay of products of **U fission produced by a thermonuclear neutron spectrum. 6 810 20 40 60 100 YEARS —————_—__—--—_+| NOILLVWYHOd STHEdd- evgaTIONN ACTIVITY, DIS/SEC PER 10* FISSIONS lo-!