The external hot gas cleanup system, designed for installation on the PDU at Waltz Mill, PA, consists of an external fixed bed desulfurizer of zinc ferrite sorbent, a tertiary particulate removal system (a sintered metal filter and venturi scrubber), and associated piping and instrumentation. The design report for this system was finalized. During the reporting period, PDU structural work was completed and the fixed bed desulfurizer was installed. Candidate samples of zinc ferrite sorbent were procured from United Catalysts, Inc. (2.89/lb) and from AMAX Extractive R and D, Inc. (4.80/lb). These sorbents will be pretested at the US Dept. of Energy Morgantown Energy Technology Center (DOE/METC) before they are tested in the desulfurizer at the PDU. In addition, purchase orders were released for a 5100 lb/hr steam supply system and for components to upgrade the PDU data acquisition system.