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Assessment and improvements of thermal-hydraulic correlations and methods for the analysis of the Jules Horowitz Reactor
Doktorsavhandling, 2017

Flow instability

Uncertainty

Narrow channels

Jules Horowitz Reactor

Safety analysis

Critical heat flux

Thermal-hydraulic correlations

Heat transfer

Best-Estimate

Material Testing Reactor

## Författare

### Alberto Ghione

Chalmers, Fysik, Subatomär fysik och plasmafysik

### Assessment of Critical Heat Flux correlations in narrow rectangular channels

Proceedings of the 11th International Topical Meeting on Nuclear Thermal Hydraulics, Operation and Safety (NUTHOS-11), Gyeongju, Korea, Oct. 9-13 2016,; (2016)

**Paper i proceeding**

### Assessment of thermal–hydraulic correlations for narrow rectangular channels with high heat flux and coolant velocity

International Journal of Heat and Mass Transfer,; Vol. 99(2016)p. 344-356

**Artikel i vetenskaplig tidskrift**

### Criteria for onset of flow instability in heated vertical narrow rectangular channels at low pressure: an assessment study

International Journal of Heat and Mass Transfer,; Vol. 105(2017)p. 464-478

**Artikel i vetenskaplig tidskrift**

### Ghione A., Noel B., Vinai P., Demazière C., Uncertainty and sensitivity analysis for the simulation of a station blackout scenario in the Jules Horowitz Reactor

Although the JHR core is small, the performances are rather extreme. In fact the experiments require large neutron fluxes to develop irradiation effects typical of nuclear power plants, over short time periods. Therefore significant heat fluxes are generated in the core, and the cooling is achieved with water at high velocity through narrow channels.

When operating a nuclear reactor, a sufficient level of safety have to be assured in order to minimize the potential for radioactivity releases to the environment. The safety analysis relies on computational methods developed for the simulation of the system behavior. In particular, a thermal-hydraulic modeling is needed to study the cooling of the reactor under a variety of scenarios.

In this doctoral thesis possible improvements of the thermal-hydraulic modeling of the JHR are proposed. From the investigation of proper experiments, heat transfer correlations and criteria of flow instability and boiling crisis are recommended for the specific case of the JHR. Moreover, a more realistic approach is tested for the safety analysis of the JHR, where the correlations optimized for the reactor are combined with an evaluation of the input and modeling uncertainties.

### Ämneskategorier

Materialteknik

Subatomär fysik

### ISBN

978-91-7597-520-7

Doktorsavhandlingar vid Chalmers tekniska högskola. Ny serie: 4201

### Utgivare

Chalmers tekniska högskola

PJ lecture hall, Origo, Kemigården 1, Chalmers

Opponent: Dr. Dominique Bestion, Commissariat à l'énergie atomique et aux énergies alternatives (CEA), Grenoble, France