Gas Generation from K East Basin Sludges and Irradiated Metallic Uranium Fuel Particles Series III Testing

Schmidt, Andrew J. ; Delegard, Calvin H. ; Bryan, Samuel A. ; Elmore, Monte R. ; Sell, Rachel L. ; Silvers, Kurt L. ; Gano, Susan R. ; Thornton, Brenda M.

Pacific Northwest National Laboratory (U.S.)

关键词: Gas Generation;    Fuel Particles;    Oxidation;    Reaction Rate;    Cover Gas;   

DOI  :  10.2172/15010540
RP-ID  :  PNNL-14346
RP-ID  :  AC05-76RL01830
RP-ID  :  15010540

美国|英语

来源: UNT Digital Library

【 摘 要 】

The path forward for managing of Hanford K Basin sludge calls for it to be packaged, shipped, and stored at T Plant until final processing at a future date. An important consideration for the design and cost of retrieval, transportation, and storage systems is the potential for heat and gas generation through oxidation reactions between uranium metal and water. This report, the third in a series (Series III), describes work performed at the Pacific Northwest National Laboratory (PNNL) to assess corrosion and gas generation from irradiated metallic uranium particles (fuel particles) with and without K Basin sludge addition. The testing described in this report consisted of 12 tests. In 10 of the tests, 4.3 to 26.4 g of fuel particles of selected size distribution were placed into 60- or 800-ml reaction vessels with 0 to 100 g settled sludge. In another test, a single 3.72-g fuel fragment (i.e., 7150-mm particle) was placed in a 60 ml reaction vessel with no added sludge. The twelfth test contained only sludge. The fuel particles were prepared by crushing archived coupons (samples) from an irradiated metallic uranium fuel element. After loading the sludge materials (whether fuel particles, mixtures of fuel particles and sludge, or sludge-only) into reaction vessels, the solids were covered with an excess of K Basin water, the vessels closed and connected to a gas measurement manifold, and the vessels back-flushed with inert neon cover gas. The vessels were then heated to a constant temperature. The gas pressures and temperatures were monitored continuously from the times the vessels were purged. Gas samples were collected at various times during the tests, and the samples analyzed by mass spectrometry. Data on the reaction rates of uranium metal fuel particles with water as a function of temperature and particle size were generated. The data were compared with published studies on metallic uranium corrosion kinetics. The effects of an intimate overlying sludge layer (''blanket'') on the uranium metal corrosion rates were also evaluated.