Novel simulation technique of radioactive aerosol substances propagation into the motionless atmosphere suddenly disseminated by wind to surrounding environment

0545515 - ÚTIA 2022 RIV US eng J - Journal Article
Pecha, Petr - Kárný, Miroslav
Novel simulation technique of radioactive aerosol substances propagation into the motionless atmosphere suddenly disseminated by wind to surrounding environment.
Annals of Nuclear Energy. Roč. 165, č. 1 (2022), č. článku 108686. ISSN 0306-4549
R&D Projects: GA MŠMT(CZ) LTC18075
EU Projects: European Commission(XE) CA16225
Institutional support: RVO:67985556
Keywords : Calm atmosphere * Aerosol dispersion and deposition * Pollution dissemination * Hot spot occurrence * Non-Gaussian sum * Kullback-Leibler divergence
OECD category: Computer sciences, information science, bioinformathics (hardware development to be 2.2, social aspect to be 5.8)
Impact factor: 1.9, year: 2022
Method of publishing: Limited access
https://www.sciencedirect.com/science/article/pii/S0306454921005624?via%3Dihub

Accidental discharges of radioactive aerosol into the motionless (calm) atmosphere are examined with aim to quantify ensuing radiological impact on population. This paper offers an advanced methodology that facilitates and accelerates the demanding modelling process in the calm region. The modelling simulates continuous, quite volatile, radioactive releases under strong variations of the atmospheric conditions by a chain of discrete Gaussian pulses. An original idea of insertion of the nested inner cycle enables to comprise the atmosphere state changes during individual pulse propagation. The radioactivity concentration in air at the calm end period becomes a quite non-Gaussian sum of the Gaussian puffs. The novel processing provides a simple and sufficiently precise estimate of its statistical properties. The processing approximates the sum by a single “super-puff” distribution of the Gaussian type. It remarkably facilitates analysis of the ensuing convective transport of the radioactivity package. Instead of many calculating runs of the convective transport for each individual puff, only one run realises. The approximation is based on Bayes’ paradigm (AB). The numerical experiments confirm the acceptability of the AB procedure under the inspected circumstances. The proposed way converts the laborious modelling of radiological fields into a feasible one. It supports practicability of the sampling based methods of uncertainty and sensitivity analyses, as well as the data assimilation methods, especially their inverse modelling techniques based on simulation of multiplex radiological trajectories.
Permanent Link: http://hdl.handle.net/11104/0322205