Pyrophoricity of uranium
Uranium metal is pyrophoric and is capable of self-ignition in air provided conditions are favorable. Based on the data in this report, spontaneous ignition of spherical particles larger than 1/16 inch in diameter would not be expected to occur in air at room temperature (25[degree]C). The rate at which the uranium surface oxidizes in air, balanced against the rate at which the heat of reaction is lost to the surroundings, determines whether spontaneous ignition can occur. Heat loss to the surrounding environment depends on the thermal conductivity of the uranium including the oxide coating, and on the temperature gradient. The ignition temperature for uranium metal particles is a function of particle geometry, size or specific surface area, heating rate gas composition as well as the quantity and distribution of powder within a storage container. The most important variable; however, affecting the ignition temperature for single samples was found by Schnizlein and Bingle to be the specific surface area (surface area per gram) of the uranium particles. The ignition temperatures calculated from ANL data for 1/16, 1/4, and 1/2 inch diameter spherical particles are 333, 375, and 399[degree]C, respectively. The accuracy is believed to be about [plus minus]l0%, which is based on theoretical and experimental results.
- Research Organization:
- Savannah River Site (SRS), Aiken, SC (United States)
- Sponsoring Organization:
- USDOE; USDOE, Washington, DC (United States)
- DOE Contract Number:
- AC09-89SR18035
- OSTI ID:
- 6783661
- Report Number(s):
- WSRC-TR-92-106; ON: DE93012138
- Country of Publication:
- United States
- Language:
- English
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Related Subjects
ORGANIC
PHYSICAL AND ANALYTICAL CHEMISTRY
38 RADIATION CHEMISTRY, RADIOCHEMISTRY, AND NUCLEAR CHEMISTRY
36 MATERIALS SCIENCE
URANIUM
CORROSION
IGNITION
OXIDATION
ANL
HELIUM
SURFACES
THERMAL CONDUCTIVITY
THERMODYNAMICS
ACTINIDES
CHEMICAL REACTIONS
ELEMENTS
FLUIDS
GASES
METALS
NATIONAL ORGANIZATIONS
NONMETALS
PHYSICAL PROPERTIES
RARE GASES
THERMODYNAMIC PROPERTIES
US AEC
US DOE
US ERDA
US ORGANIZATIONS
400800* - Combustion
Pyrolysis
& High-Temperature Chemistry
400702 - Radiochemistry & Nuclear Chemistry- Properties of Radioactive Materials
360105 - Metals & Alloys- Corrosion & Erosion
360104 - Metals & Alloys- Physical Properties