Izvestiya vuzov. Yadernaya Energetika

The peer-reviewed scientific and technology journal. ISSN: 0204-3327

Calculation Model and Static Parameters of the IBR-2M Reactor

12/10/2025 2025 - #04 Physics in nuclear power engineering

Vdovin Y.A. Verkhoglyadov A.E.

DOI: https://doi.org/10.26583/npe.2025.4.14

UDC: 621.039.573

This article presents the development of a three-dimensional model of the IBR-2M pulsed fast reactor, used at the Joint Institute for Nuclear Research (JINR, Dubna) for physics experiments with neutron beams. The primary goal of the study is to create a detailed model for analyzing reactivity changes during core element deformations and calculating power feedback. The model incorporates key reactor components: the core with 69 fuel assemblies, the PO-3 reactivity modulator with movable reflectors, the steel vessel, control and protection system (CPS) elements, and liquid sodium coolant. To verify the model, criticality calculations of static parameters were performed using the Monte Carlo method with evaluated nuclear data libraries JEFF-3.2. The results, including the effective neutron multiplication factor (keff ≈ 1.002 – 1.003), neutron generation lifetime (∼60 – 65 ns), and modulator efficiency (∼2.6 – 2.9% in keff), were compared with experimental data. Minor discrepancies were identified, attributed to uncertainties in geometry and isotopic composition. The energy release distribution and specific reactivity across the core were approximated using functions accounting for radial and axial positions of elements. For instance, the energy release is described by a cosine-type function, while the specific reactivity distribution in the core can be represented by a squared cosine function. The findings confirm the applicability of the model for studying the dynamics of pulsed reactor operation. The obtained data will be used to analyze power feedback and optimize IBR-2M parameters. Precise energy release and reactivity distribution functions in the core will enable analytical calculations of various dynamic processes.

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IBR-2M pulsed fast reactor 3D reactor model neutron physics calculations Monte Carlo method effective neutron multiplication factor reactor core energy release distribution specific reactivity power feedback dynamics of a pulsed reactor

Link for citing the article: Vdovin Y.A., Verkhoglyadov A.E. Calculation Model and Static Parameters of the IBR-2M Reactor. Izvestiya vuzov. Yadernaya Energetika. 2025, no. 4, pp. 199-199; DOI: https://doi.org/10.26583/npe.2025.4.14 (in Russian).

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