The post-extrusion processing of the U-- Zr tubes for irradiation in NHU was continued. Production of the enriched prototype tubes for Vallecitos is proceeding satisfactorily. A cost reduction evaluation for shortening the front and rear Zircaloy end seal tube sections is under way, The reasons for different corrosion results in heat-treated tubes tested under simulated reactor shutdown conditions were investigated. (for preceding period see NMl-4381.) (W.D.M.)