Nuclear power plants are intense sources of antineutrinos. Their energy spectrum and emitted flux depend on the composition of the nuclear fuel and on the thermal power of the reactor. These properties led to potential applications of neutrino physics: they could be used to non intrusively monitor a nuclear reactor. To this purpose, a better knowledge of the antineutrino energy spectra arising ...

High level Liquid Waste (HLW) is generated during the reprocessing of spent nuclear fuel which is used to recover uranium and plutonium. More than 99% of the radioactivity generated during the burning of nuclear fuel in the reactor is present in HLW. For the efficient management of HLW either by vitrification in the suitable borosilicate glass matrix, or partitioning and transmutation (P&T) of ...

The source of all liquid, gaseous and solid radioactive waste in the pressure water reactor (PWR) nuclear power plant (NPP) originate from leakage of fission products out of the fuel rods into the primary coolant and neutron activation of materials within and around the primary coolant system and reactor vessel. The source term design used to determine the concentrations of radionuclides in the...

Argonne National Laboratory (ANL), along with other national laboratories, has been developing a solvent extraction process for partitioning of spent fuel constituents to lead to safer and cheaper disposal of high-level waste. The process, known as UREX+, separates key radionuclides from dissolved spent fuel into: (1) uranium for disposal as LLW, (2) technetium for disposal as HLW, (3) iodine f...

Most HWRs currently use natural uranium fuel. Using enriched uranium fuel results in a significant improvement in fuel cycle costs and uranium utilization. On the other hand, reactivity changes of HWRs over the full range of operating conditions from cold shutdown to full power are small. This reduces the required reactivity worth of control devices and minimizes local flux distribution perturb...

A method is proposed for determining power-density profiles in nuclear reactor fuel rods from neutron flux measurements obtained by multiple in-core micropocket fission detectors (MPFD). A general formulation is presented that relates the power-density profiles in a reactor’s fuel rods to the flux density at detector locations. Key to this formulation is the construction of an appropriate respo...

For the purpose of developing the capability to produce fission Mo, the Chilean Nuclear Energy Commission is participating in the IAEA Coordinated Research Project: “Developing Techniques for Small Scale Indigenous Mo-99 Production using LEU Fission or Neutron Activation”. Fission Mo will be produced irradiating, at RECH-1 reactor, a target made of a LEU metallic uranium foil held between two c...

The PUREX technology based on aqueous processes is currently the leading reprocessing technology in nuclear energy systems. It seems to be the most developed and established process for light water reactor fuel and the use of solid fuel. However, demand driven development of the nuclear system opens the way to liquid fuelled reactors, and disruptive technology development through the applicatio...

The nuclear fuel cycle can be truly closed by supp lementing today’s thermal reactors with fast reactors, which can use as fuel the heavy, fissionable isotopes that accumulate in thermal-reactor fuel. In a fully closed cycle, the waste for disposal consists only of fission products with trace amounts of actinides. Eliminating the transuranics reduces the heat load in the repository, increasing ...

Nuclear accidents that lead to melting of a reactor core create heterogeneous materials containing hundreds of radionuclides, many with short half-lives. The long-lived fission products and transuranium elements within damaged fuel remain a concern for millennia. Currently, accurate fundamental models for the prediction of release rates of radionuclides from fuel, especially in contact with wat...