The present work is an outgrowth of studies made in support of CRBR licensing, but the conclusions drawn should be generally applicable to oxide-fueled LMFBR's. The accident under consideration is a 10 cents/s unprotected TOP (transient overpower), for which a series of PLUTO2/SAS4A calculations has been performed using a higher power CRBR EOC3 fuel pin which had 275 days irradiation. The assumption was made in the licensing work that a short pin failure will occur at the axial midplane, maximizing the positive fuel motion reactivity effect, as it was felt that a less conservative assumption could not be conclusively justified. This assumption is also made in the present case.

This report covers the second quarter of activity on the project to characterize the mineral-matter liberation and the beneficiation of ultra-fine coal. So far the work has been confined to the base-case coal from the Illinois No. 6 seam. Eight other coals will be examined later in the program. The work accomplished this quarter, and described in this report, included determination of additional bulk properties of the coal, an examination of the mineral-matter and mineral associations in the coal, and the preparation and washability testing of ultra-fine, minus 44-micrometer (325-mesh) coal for liberation studies. 8 references, 8 figures, 13 tables.