During the past several years, a comprehensive high fidelity reactor core modeling capability has been developed called the Numerical Nuclear Reactor (NNR) for detailed analysis of Light Water Reactors. The project was initially sponsored as part of a US-ROK collaborative DOE I-NERI project and the past two years has been sponsored by EPRI to address specific fuel performance issues as part of ...

Recent measurements of the positron energy spectrum obtained from inverse beta decay interactions of reactor electron antineutrinos show an excess in the 4 to 6 MeV region relative to current predictions. First-principles calculations of fission and beta decay processes within a typical pressurized water reactor core identify prominent fission daughter isotopes as a possible origin for this exc...

To simulate the behaviour of a nuclear power reactor it is necessary to be able to integrate the time-dependent neutron diffusion equation inside the reactor core. In particular, we will consider here VVER-type reactors which use the neutron diffusion equation discretized on hexagonal meshes. Several algorithms to integrate the time dependent neutron diffusion equation have been developed, by m...

For the validation of Computational Fluid Dynamics (CFD) codes experimental data on fluid flow parameters with high resolution in time and space are needed. ROCOM (Rossendorf Coolant Mixing Model) is a test facility for the investigation of coolant mixing in the primary circuit of pressurized water reactors. This facility describes the primary circuit of a German KONVOI type reactor. All import...

Résumé. On applique dans cet article une méthode d'optimisation géométrique dans le cadre de la conception d'un c÷ur de réacteur SFR dans le but de minimiser une contre réaction thermique connue sous le nom d'e et de vidange sodium. Lorsqu'une augmentation de température survient, ce type de réacteur peut être sujet à une forte augmentation de réactivité, un paramètre clé dans le contrôle de la...

A recurrent multilayer perceptron (RMLP) model is designed and developed for simulation of core neutronic phenomena in a nuclear power plant, which constitute a non-linear, complex dynamic system characterized by a large number of state variables. Training and testing data are generated by REMARK, a rst principles neutronic core model 16]. A modiied backpropagation learning algorithm with an ad...

Stable power processes are never guaranteed. An assortment of unstable behaviors wrecks power apparatus, including mechanical vibration, malfunctioning control apparatus, unstable fluid flow, unstable boiling of liquids, or combinations thereof. A necessary condition for stable reactor power is that the reactor distortion accompanying a temperature rise decreases the reactivity, thus slowing an...

A mathematical representation for a polycrystalline, thin-tape, ferromagnetic metal is derived for the operating conditions found during flux resetting in a magnetic amplifier. The starting point for the derivation is the dynamic behavior of the magnetization process in ferromagnetic single crystals reported in the literature. The general reactor representation is simplified to a form which is ...

In this paper, we used a neutron diffusion hybrid equation with an external neutron source to calculate nuclear power factors in each fuel element in the reactor core. We used the nodal expansion method to obtain the neutron flux for a given control rods bank position. The results were compared with results obtained for eigenvalue problem near criticality condition and fixed source problem duri...

The first result of the neutrino magnetic moment measurement at the Kalininskaya Nuclear Power Plant (KNPP) with the GEMMA spectrometer is presented. An antineutrino-electron scattering is investigated. A high-purity germanium detector of 1.5 kg placed 13.9 m away from the 3 GW reactor core is used in the spectrometer. The antineutrino flux is 2.73×1013 ν̄e/cm/s. The differential method is used ...