PROBLEMS OF ATOMIC SCIENCE AND TECHNOLOGY
Series: Nuclear and Reactor Constants

since 1971

Русский (РФ)

ISSN 2414-1038 (online)

COMPUTATIONAL METHODOLOGIES FOR CRITICAL HEAT FLUX PREDICTION IN PRESSURIZED WATER REACTORS AND FEASIBILITY ASSESSMENT OF PHENOMENOLOGICAL DNB MODELS

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Authors & Affiliations

Zubkov A.G., Oleksyuk D.A., Vertikov E.A., Noskov A.S.
National Research Centre “Kurchatov Institute”, Moscow, Russia

Zubkov A.G. – Researcher. Contacts: 1, pl. Akademika Kurchatova, Moscow, Russia, 123182.Tel.: +7 (926) 282-56-58; e-mail: This email address is being protected from spambots. You need JavaScript enabled to view it..
Oleksyuk D.A. – Head of the Department, Cand. Sci. (Tech.).
Vertikov E.A. – Junior Researcher.
Noskov A.S. – Head of Laboratory.

Abstract

This paper analyzes conventional methodologies used in domestic and international practice for calculating Critical Heat Flux (CHF) during Departure from Nucleate Boiling (DNB) in subcooled liquid flow, for subsequent determination of the Departure from Nucleate Boiling Ratio (DNBR) when assessing thermal-hydraulic reliability of VVER and PWR reactor cores. The study describes empirical correlations, look-up CHF tables, and three well-known phenomenological DNB models: bubble crowding model (BC), liquid sublayer dryout model (LSD), and dry spots area enlarging. An analytical comparison is performed between classical correlations across wide operational parameter ranges, along with benchmarking of VVER/PWR design correlations against phenomenological models using representative experimental datasets. Results demonstrate both qualitative and quantitative agreement between CHF values obtained through different calculation methods and experimental data. The paper presents a modified BC model and its implementation methodology in the subchannel code SC-INT, previously validated for local coolant parameter calculations (temperature, velocity, and pressure drop) based on experimental studies in VVER rod bundle. The upgraded model is compared against the Bezrukov correlation using 2300 data points from the Kurchatov Institute's CHF database for rod bundles.

Keywords
heat transfer crisis, Departure from Nucleate Boiling, Critical Heat Flux, flow boiling, Departure from Nucleate Boiling Ratio, DNB models, local parameters of the coolant, DNB, DNBR, VVER, PWR

Article Text (PDF, in Russian)

References

UDC 621.181.6

Problems of Atomic Science and Technology. Series: Nuclear and Reactor Constants, 2025, no. 2, 2:22