Cross-Section Homogenization for Reactivity-Induced Transient Calculations

Dugan, Kevin; Zmijarevic, Igor; Sanchez, Richard

doi:10.1080/23324309.2016.1188116

Cited by 6 publications

(2 citation statements)

References 15 publications

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“…For more severe kinetic problems, it is known (Dugan et al, 2016) that using more faithful model fluxes for the weighting procedure is mandatory. In any case we will suppose that a good starting point is the critical…”

Section: Iterative Strategymentioning

confidence: 99%

A MOC-based neutron kinetics model for noise analysis

Gammicchia

Santandrea

Zmijarevic

et al. 2020

Annals of Nuclear Energy

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A 2-D noise model is implemented in the deterministic reactor code APOLLO3 R to simulate a periodic oscillation of a structural component. The Two/Three Dimensional Transport (TDT) solver, using the Method of Characteristics, is adopted for the calculation of the case studies, constituted by a moving detector and control-rod bundle. The periodic movement is built by properly linking the geometries corresponding to the temporal positions. The calculation is entirely performed in the real time domain, without resorting to the traditional frequency approach. A specifically defined dynamic eigenvalue is used to renormalize in average the reactivity over a period. The algorithm is accelerated by the DP N synthetic method. For each cell of the domain, the time values of fission rates are analysed to determine the noise extent. Moreover we propose a systematic approach to the definition of the macroscopic cross sections to be used in dynamical calculations starting from library data. As an aside of our work we have found that even in static calculation this approach can produce significant changes.

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Section: Iterative Strategymentioning

confidence: 99%

A MOC-based neutron kinetics model for noise analysis

Gammicchia

Santandrea

Zmijarevic

et al. 2020

Annals of Nuclear Energy

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“…In practical calculations of nuclear reactors, as a rule, simpler systems of equations in the multigroup diffusion approximation are used (Marchuk and Lebedev, 1986;Lewis and Miller, 1993;Sutton and Aviles, 1996;Cho, 2005). Currently diffusion models are derived and applied using sophisticated homogenization methodologies (see Sanchez (2009) ;Dugan et al (2016)) which define parameters of the multigroup diffusion equations that enable one to take into account transport effects.…”

Section: Introductionmentioning

confidence: 99%

State change modal method for numerical simulation of dynamic processes in a nuclear reactor

Avvakumov

Strizhov

Vabishchevich

et al. 2018

Progress in Nuclear Energy

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Modeling of dynamic processes in nuclear reactors is carried out, mainly, on the basis of the multigroup diffusion approximation for the neutron flux. The basic model includes a multidimensional set of coupled parabolic equations and ordinary differential equations. Dynamic processes are modeled by a successive change of the reactor states, which are characterized by given coefficients of the equations. In the modal method, the approximate solution is represented as an expansion on the first eigenfunctions of some spectral problem. The numerical-analytical method is based on the use of dominant time-eigenvalues of a multigroup diffusion model taking into account delayed neutrons. Numerical simulations of the dynamic process were performed in the framework of the two-group approximation for the VVER-1000 reactor test model. The last is characterized by the fact that some eigenvalues are complex.

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