Repost of Lapp’s 1971 article, note discussion on page 3 (image 3) of core behavior in dry sand.
Ralph Lapp – Thoughts on Nuclear Plumbing, 1971. Where would you put ‘em now, Ralph?
Ralp Lapp – Unsafe core cooling systems in Reactors, 1971
NEW YORK TIMES 12 DECEMBER 1971
THOUGHTS ON NUCLEAR PLUMBING