Accident Performance of Light Water Reactor Cladding Materials

Nelson, Andrew T.¹ 

[1] Los Alamos National Laboratory

关键词: ACCIDENTS;    ACTINIDES;    ALLOYS;    COATINGS;    CONTAINMENT;    CORROSION RESISTANCE;    DEFECTS;    FISSION PRODUCTS;    FUEL CYCLE;    FURNACES;    HYDROGEN PRODUCTION;    KINETICS;    LOSS OF COOLANT;    MASS SPECTROMETERS;    MITIGATION;    OXIDATION;    RADIOACTIVITY;    REACTOR CORES;    THERMAL GRAVIMETRIC ANALYSIS;    WATER VAPOR;    ZIRCONIUM;   

DOI  :  10.2172/1047110
RP-ID  :  LA-UR-12-23387
PID  :  OSTI ID: 1047110
Others  :  TRN: US1203971

美国|英语

来源: SciTech Connect

【 摘 要 】

During a loss of coolant accident as experienced at Fukushima, inadequate cooling of the reactor core forces component temperatures ever higher where they must withstand aggressive chemical environments. Conventional zirconium cladding alloys will readily oxidize in the presence of water vapor at elevated temperatures, rapidly degrading and likely failing. A cladding breach removes the critical barrier between actinides and fission products and the coolant, greatly increasing the probability of the release of radioactivity in the event of a containment failure. These factors have driven renewed international interest in both study and improvement of the materials used in commercial light water reactors. Characterization of a candidate cladding alloy or oxidation mitigation technique requires understanding of both the oxidation kinetics and hydrogen production as a function of temperature and atmosphere conditions. Researchers in the MST division supported by the DOE-NE Fuel Cycle Research and Development program are working to evaluate and quantify these parameters across a wide range of proposed cladding materials. The primary instrument employed is a simultaneous thermal analyzer (STA) equipped with a specialized water vapor furnace capable of maintaining temperatures above 1200 C in a range of atmospheres and water vapor contents. The STA utilizes thermogravimetric analysis and a coupled mass spectrometer to measure in situ oxidation and hydrogen production of candidate materials. This capability is unprecedented in study of materials under consideration for reactor cladding use, and is currently being expanded to investigate proposed coating techniques as well as the effect of coating defects on corrosion resistance.