Wet Sand, Water Scenario

For this case the k-effective was 0.975 0.001 much closer to the margin of 0.985 

This accident scenario involved the reactor being buried in Si02 with a density of 1.5 g/cc. This is a median point between the density of loose sand (1.4 g/cc) and. dry, packed sand (1.6 g/cc). The core is not flooded in this case, and the radial reflectors have been removed. While little moderation occurred in the sand and Si02 is an inferior scattering medium to BeO (and is also without the (n,2n) reaction), the reactor was going from somewhat reflected to essentially infinite reflection conditions. In a variety of cores this had led to a net increase in reactivity. This effect is highly dependent on the density of the sand. This core had a k-effective of 0.981 0.001 for this scenario. 

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