Zirconium-based alloys are used in water-cooled nuclear reactors for both nuclear fuel cladding and structural components. Under this harsh environment, the main factor limiting the service life of zirconium cladding, and hence fuel burn-up efficiency, is water corrosion. This oxidation process has recently been linked to the presence of a sub-oxide phase with well-defined composition but unkno...

Missing pellet surface (MPS) defects are local geometric defects in nuclear fuel pellets that result from pellet mishandling or manufacturing. The presence of MPS defects can cause clad stress concentrations that are substantial enough to produce through-wall cladding failure for certain combinations of fuel burnup, and reactor power level or power change. Consequently, the impact of potential ...

A review of the chemistry occurring inside a nuclear power plant during a serious reactor accident is presented. This includes some aspects of the behavior of nuclear fuel, its cladding, cesium and iodine. This review concentrates on the chemistry of an accident in a water-cooled reactor loaded with uranium dioxide or mixed metal oxide fuel. Subjects: Chemistry; Environmental Chemistry; Inorgan...

Zirconium-based alloys are widely used in the field of nuclear industry as cladding for nuclear fuel in power plants. In a pressurized water reactor (PWR), boric acid is added in the coolant for reactivity control. Lithium hydroxide is added to render the coolant slightly alkaline, which helps to inhibit corrosion product deposition on the fuel cladding and reduces the corrosion rate of structu...

Feasibility tests were initiated to determine if the zirconium in commercial used nuclear fuel (UNF) cladding can be recovered in sufficient purity to permit re-use, and if the recovery process can be operated economically. Initial tests are being performed with unirradiated, non-radioactive samples of various types of Zircaloy materials that are used in UNF cladding to develop the recovery pro...

A two-dimensional computational model of a loaded used nuclear fuel canister filled with helium gas was constructed to predict the cladding temperature during vacuum drying conditions. It includes distinct regions for the fuel pellets, cladding and helium within each basket opening. Symmetry boundary conditions are employed so that only one-eighth of the package cross-section is included, and t...

Contact between the outer surface of a fuel pellet and the inner surface of the fuel rod cladding can result in several kinds of undesirable behavior. As the pellet swells outward and the cladding creeps down, large stresses are generated in both the pellet and the cladding. This contact may exacerbate chemical degradation of the cladding and the stress may enable rapid propagation of cracks. B...

To increase the power density and maximum allowable fuel burnup in light water reactors, new fuel rod designs are investigated. Such fuel is desirable for improving the economic performance light water reactors loaded with transuranic-bearing fuel for transmutation, as well as those using UO2 fuel. A proposal for using silicon carbide duplex as fuel cladding is investigated. The cladding consis...