Studies are under ray in Chemical Research and Development to-provide the technical ``know-how`` necessary to calcine Purex 1WW and safely store the solid product. The solid product can be stored as the particulate solid from the calciner or, after further treatment, as a solid matrix or melt. In this regard, Chemical Research is studying a PO{sub 4}BO{sub 2} melt. This document presents expected fission product heat generation rates in the solid product, shows the effect of various variables on heat transfer in the stored solid, and emphasizes certain items for further study. Also a vault cooling method is suggested for further study.

The problem of controlling the surface temperatures of core vessels in two-region aqueous homogeneous reactors has been examined by analyzing several possible systems for cooling the wall: (1) direction of the inlet core fluid along the wall at a high velocity; (2) passage of heavy water through the wall of a double-wall core vessel; and (3) flow of cool blanket slurry past the wall.