4 oN Laws We emphasize that these Goffman and Tamplin projections are very. pessimistic. Other projections are less by an order of magnitude or even orders of magnitude. Nevertheless, in “worst case" analyses of uncontrolled situations, the difficulty of reducing the internal exposure from strontium-90 might well be a limiting factor. In particular, the internal .exposure might quickly dominate when attempts are made to reduce the external exposure, and so a compromise of the extent of radiological cleanup might be found to be reasonable.