This report summarizes a collection of, synthesis of, and speculation on the geophysical and geochemical models of the earth's stable shields and rift zones. Two basic crustal types, continental and oceanic, and two basic mantle types, stable and unstable, are described. It is pointed out that both the crust and upper mantle play a strongly interactive role with surface geological phenomena ranging from the occurrence of mountains, ocean trenches, oceanic and continental rifts to geographic distributions of earthquakes, faults, and volcanoes. On the composition of the mantle, there is little doubt regarding the view that olivine constitutes a major fraction of the mineralogy of the earth's upper mantle. Studies are suggested to simulate the elasticity and composition of the earth's lower crust and upper mantle.

Information related to sodium fires and fission products in LMFBR type reactors is presented concerning SOMIX code development; sodium jet dispersal tests; aerosol leakage; high temperature-concentration aerosol tests; aerosol source term size; and properties of high temperature fuel mixtures.

Six major problem areas have surfaced in the past twenty-five years concerning the use of plutonium tankage. The most significant of these involves the use of borosilicate glass as a neutron absorber. Approximately thirty recommendations and criteria resulted from a study of these problem areas. Not all of the criteria and recommendations are unanimously supported by all members of the committee. The committee agrees that problem areas that can be handled on a short-term basis are being pursued expeditiously. Most of the criteria presented will apply to new tankage to be installed. The committee also noted fourteen accomplishments in the last 1/sup 1///sub 2/ years directed to the application of the criteria.