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FY14 Q1 Progress Report for SECA Core Technology Program

Description: This quarterly progress report was prepared under field work proposal (FWP) 40552 and covers technical work performed during the period October 1 through December 31, 2013 (FY14 1st quarter). The report highlights and documents technical progress and milestone status in tasks related to advanced cell and stack component materials development and computational design and simulation. Technical highlights related to cell and stack materials development and characterization include: • Surface modified, Ce-modified MC spinel-coated AISI 441 exhibited improved spallation resistance (compared to coated mill reference 441) after 30,000 hours of oxidation at 800ºC in air. Similar beneficial results from surface modification were observed after 26,000 hours of oxidation at 850ºC. • MnCo spinel coatings prepared from metallic powder precursors exhibited low area-specific resistance after 12,000 hours of testing at 800°C. • Long-term validation tests (6,000 hours of operation followed by 10 deep thermal cycles) of surface-blasted, spinel-coated AISI 441 interconnects were completed using PNNL’s SECA CTP stack test fixture. Results of post-test results will be reported in the next quarterly progress report. • Long-term evaluation of compliant glass seals (SCN-1 glass with YSZ fibers) was in progress using PNNL’s SECA CTP stack test fixture. • Baseline testing of LSCF-based cells from Fuel Cell Materials was performed in PNNL’s SECA CTP stack test fixture. Overall performance was similar to that previously obtained with similar cells from H.C. Starck. • A study on pore coarsening of compliant glass seals with and without inert fillers (ZrO2 short fibers or ZrO2 crushed hollow balls) has reached 2,000 hours of testing; results to date indicate that the addition of the fillers was partially effective in hindering the pore coalescence process. • Cell tests attempting to correlate effects of fuel water content on anode performance with previously observed changes in Ni/YSZ anode microstructure were initiated. Technical highlights ...
Date: January 31, 2014
Creator: Stevenson, Jeffry W. & Koeppel, Brian J.
Partner: UNT Libraries Government Documents Department

FY13 Annual Progress Report for SECA Core Technology Program

Description: This progress report covers technical work performed during fiscal year 2013 at PNNL under Field Work Proposal (FWP) 40552. The report highlights and documents technical progress in tasks related to advanced cell and stack component materials development and computational design and simulation. Primary areas of emphasis for the materials development work were metallic interconnects and coatings, cathode and anode stability/degradation, glass seals, and advanced testing under realistic stack conditions: Metallic interconnects and coatings • Effects of surface modifications to AISI 441 (prior to application of protective spinel coatings) on oxide scale growth and adhesion were evaluated as a function of temperature and time. Cathode stability/degradation • Effects of cathode air humidity on performance and stability of SOFC cathodes were investigated by testing anode-supported cells as a function of time and temperature. • In-situ high temperature XRD measurements were used to correlate changes in cathode lattice structure and composition with performance of anode-supported button cells. Anode stability/degradation • Effects of high fuel steam content on Ni/YSZ anodes were investigated over a range of time and temperature. • Vapor infiltration and particulate additions were evaluated as a potential means of improving tolerance of Ni/YSZ anodes to sulfur-bearing fuel species. Glass seals • A candidate compliant glass-based seal materials were evaluated in terms of microstructural evolution and seal performance as a function of time and temperature. Stack fixture testing • The SECA CTP stack test fixture was used for intermediate and long-term evaluation of candidate materials and processes. Primary areas of emphasis for the computational modeling work were coarse methodology, degradation of stack components, and electrochemical modeling: Coarse methodology • Improvements were made to both the SOFC-MP and SOFC ROM simulation tools. Degradation of stack components • Thermo-mechanical modeling and validation experiments were performed to understand/mitigate degradation of interconnects and seals during long-term ...
Date: January 31, 2014
Creator: Stevenson, Jeffry W. & Koeppel, Brian J.
Partner: UNT Libraries Government Documents Department

Spent Fuel Transportation Package Response to the Baltimore Tunnel Fire Scenario

Description: On July 18, 2001, a freight train carrying hazardous (non-nuclear) materials derailed and caught fire while passing through the Howard Street railroad tunnel in downtown Baltimore, Maryland. The United States Nuclear Regulatory Commission (USNRC), one of the agencies responsible for ensuring the safe transportation of radioactive materials in the United States, undertook an investigation of the train derailment and fire to determine the possible regulatory implications of this particular event for the transportation of spent nuclear fuel by railroad. Shortly after the accident occurred, the USNRC met with the National Transportation Safety Board (NTSB, the U.S. agency responsible for determining the cause of transportation accidents), to discuss the details of the accident and the ensuing fire. Following these discussions, the USNRC assembled a team of experts from the National Institute of Standards and Technology (NIST), the Center for Nuclear Waste Regulatory Analyses (CNWRA), and Pacific Northwest National Laboratory (PNNL) to determine the thermal conditions that existed in the Howard Street tunnel fire and analyze the effects of this fire on various spent fuel transportation package designs. The Fire Dynamics Simulator (FDS) code, developed by NIST, was used to determine the thermal environment present in the Howard Street tunnel during the fire. The FDS results were used as boundary conditions in the COBRA-SFS and ANSYS® computer codes to evaluate the thermal performance of different package designs. The staff concluded that larger transportation packages resembling the HOLTEC Model No. HI STAR 100 and TransNuclear Model No. TN-68 would withstand a fire with thermal conditions similar to those that existed in the Baltimore tunnel fire event with only minor damage to peripheral components. This is due to their sizable thermal inertia and design specifications in compliance with currently imposed regulatory requirements. The staff also concluded that some components of smaller transportation packages resembling ...
Date: November 15, 2006
Creator: Adkins, Harold E.; Cuta, Judith M.; Koeppel, Brian J.; Guzman, Anthony D. & Bajwa, Christopher S.
Partner: UNT Libraries Government Documents Department