AQUEOUS HOMOGENEOUS REACTOR FUEL TECHNOLOGY
Development of the technology of uranyl sulfate solutions and thoria slurries for power breeder reactors is outlined. In uranyl sulfate systems phase separations can occur in thae temperature range of 250 to 300 deg C, although additions of sulfuric acid and alkali metal sulfates are effective in suppressing these. Dissolved copper is completely effective in recombining thae hydrogen (or deuterium) and oxygen which are produced by the radiolytic decomposition of water in fissioning uranyl suifate solutions. Alloys considered most as materials of construction for homogeneous reactors are Zircaloy2, austenitic stainless steels, and commercially pure titanium. Austenitic stainless steels develop a protective anhydrous alpha F/sub 2/O/sub 3/ film at 250 deg C and higher temperatures. Stability of thae film depends on solution composition, rate of flow and temperature. In the absence of an oxidant such as oxygen, uranyl ion is reduced and a very corrosive solution is formed. Crevices and stagnant regions where oxygen depletion can be encountered must be avoided. The out-of-pile corrosion behavior of stainless steel is relatively unchanged by exposure to a solution in which fission is taking place but where evpesure is to solution circulating outside thae nentron flux region. Zircaloy-2 is very resistant to attack in non-fissioning solutions. In-pile the corrosion rate increases with increasing power density and temperature. Titanium generally behaves like Zircaloy-2 but the in-pile corrosion rates are lower. Products accumulate in reactor solutions as a result of nuclear and corrosion processes and must be removed. The chemical behavior of some of thae products has been investigated as have methods for their removal. Materials like iron, zirconium, barium, and the rare earths form insoluble salts or hydrolysis products which can be removed by filtration or centrifugation methods. Nickel, manganese, and cesium are soluble and are removed by solvent extraction or by separation of the uranium as a peroxide precipitate. Iodine, xenon, and krypton can be removed by stripping the fuel solution with oxygen or steam. Important progress has been made in developing thorium oxide slurry fuels for power breeder reactors. Thoria has been produced witha controlled particle size, shape and surface area. The effects of firing temperatare in the range of 450 to 16O0DEC, and the effects of pH and additives such as sulfate and silicate on the thoria properties have been investigated. Slurries have been irradinted at power densities and for times equivalent to thaose expected in a thorium breeder blanket without important change in properties. Molybdenum oxide is a promising catalyst for recombining radiolytic gas. Heat transfer and fiuid flow characteristics in both laminar and turbulent flow can be related to conventional correlations for Newtonian fluids through the non-Newtonian rheologic coefficients. Corrosion acd erosiou of structural materiats are governed by the size and shape of the particles, the concentration and velocity and by the presence of additives. Data are being obtained to show the effects of radiation on corrosion. Thoria slurries have been circulated in engineering equipment for thousands of hours. Corrosion and erosion have been a problem only in the circulating pumps and in very high velocity or turbulence regions in the piping and valves. (auth)
- Research Organization:
- Oak Ridge National Lab., Tenn.
- NSA Number:
- NSA-12-015118
- OSTI ID:
- 4306495
- Report Number(s):
- A/CONF.15/P/2391
- Resource Relation:
- Other Information: Prepared for the Second U.N. International Conference on the Peaceful Uses of Atomic Energy, 1958. Orig. Receipt Date: 31-DEC-58
- Country of Publication:
- Country unknown/Code not available
- Language:
- English
Similar Records
HOMOGENEOUS REACTOR PROJECT QUARTERLY PROGRESS REPORT FOR PERIOD ENDING OCTOBER 31, 1955
HOMOGENEOUS REACTOR PROJECT QUARTERLY PROGRESS REPORT FOR PERIOD ENDING JANUARY 31, 1956
Related Subjects
ACIDITY
ALKALI METALS
ALLOYS
AUSTENITE
BARIUM
BLANKETS
BREEDING
CATALYSIS
CENTRIFUGATION
CESIUM
CHEMICAL REACTIONS
COMPOUNDS
CONTAMINATION
COOLANT LOOPS
COPPER
CORROSION
CORROSION PROTECTION
DECOMPOSITION
DEUTERIUM
EROSION
FILMS
FILTERS
FISSION
FLUID FLOW
FUEL SLURRIES
FUEL SOLUTIONS
FUELS
GAMMA RADIATION
GRAIN SIZE
HEAT TRANSFER
HEAVY WATER
HIGH TEMPERATURE
HOMOGENEOUS REACTORS
HYDROGEN
HYDROLYSIS
IMPURITIES
IODINE
IONS
IRON OXIDES
IRRADIATION
KRYPTON
MANGANESE
MATERIALS TESTING
MECHANICAL PROPERTIES
MECHANICAL STRUCTURES
MOLYBDENUM OXIDES
NEUTRON FLUX
NICKEL
OXIDATION
OXYGEN
POWER PLANTS
PR