Modelling of accidental radioactive releases for Ireland
MetadataShow full item record
This item's downloads: 0 (view details)
This study analyses the findings of dispersion modelling comparisons to improve the understanding of uncertainty and to influence the development of Ireland’s operational Nuclear Power Plant (NPP) accident emergency preparedness and response capabilities. Modelling radionuclides post-accidental emission contains a high level of uncertainty, especially for source term and meteorology. Using harmonised case studies; this study investigates, assesses, and quantifies the uncertainty for a set of operational and widely used dispersion models. Both model pairs; comprising of HYSPLIT-ECMWF vs FLEXPART-ECMWF at 25km and HYSPLIT-HARMONIE vs FLEXPART-WRF at 2.5km, are compared, with the differences subsequently analysed and quantified. The comparison of the model pairs quantify uncertainty in two distinct ways. Firstly, HYSPLIT-ECMWF vs FLEXPART-ECMWF, although different from each other, use the same configuration, and their comparison enables the quantification of uncertainty inherent to model differences between these two widely used dispersion models. Secondly, HYSPLIT-HARMONIE vs FLEXPART-WRF enables the quantification of uncertainty due to meteorology. Currently, in the Irish context, HYSPLIT-HARMONIE is the single regulatory model for radionuclide dispersion. HARMONIE is the national meteorology model used by the national meteorology service. Similarly, for forecast dispersion simulations over Ireland, NUI Galway use FLEXPART-WRF in a research capacity. This study also assesses and evaluates WRF for Ireland, recommending a WRF configuration for the modelling of radionuclides for Ireland. Results show that for harmonised meteorology, the inherent model differences are in the range of 20%, and this uncertainty rises to an 80% range for different operational meteorology. This study found that the difference in meteorology, rather than model differences, is the primary source of uncertainty and recommends the use of modelling ensembles for Ireland’s atmospheric transport and dispersion modelling of radionuclides. However, even at an uncertainty range of 80%, it is unlikely that a nuclear accident in the UK will be cancer-causing to the population of Ireland. This study also proposes, successfully demonstrates, and assesses a new real-time source-term estimation framework for Ireland’s operational NPP accident emergency preparedness and response capabilities. Using real-time Gamma Dose Rate (GDR) monitoring network, findings show that the source term-estimation is particularly sensitive to the a priori source term, followed by the uncertainty on the a priori source term and is least sensitive to the GDR measurements.
This item is available under the Attribution-NonCommercial-NoDerivs 3.0 Ireland. No item may be reproduced for commercial purposes. Please refer to the publisher's URL where this is made available, or to notes contained in the item itself. Other terms may apply.
The following license files are associated with this item: