A calculation model for radionuclide dispersion in the ocean and its credibility evaluation

The credibility of a calculation model of radionuclide dispersion in the ocean determines the degree of trust that developers and users place in it. In this paper, ocean experiments are conducted to verify the credibility of the established model after a nuclear leakage accident. The model is then used for predictive calculations of the dispersion and migration of radionuclides in the ocean, and a method is proposed to evaluate its credibility. The results show that the temperature and salinity of the bottom layer of the Yellow Sea calculated by the established calculation model well portray its warm current under real conditions. The hydrodynamic results adequately describe the tidal phenomena in coastal waters and are in good agreement with the seabed base measurements. Through an ocean buoy experiment, it was found that the migration path of a buoy matched well with the simulated migration path of radionuclides. The difference between simulation and experiment in direction was 4.3 degrees, and the distance error was 0.38 km. In winter, the migration path of radionuclides in the ocean always advances in rotation. In the deposition of radionuclides into the ocean through the atmosphere, they mainly disperse back and forth. With increasing time, radionuclides migrate and disperse to the southeast under the influence of tidal and north winds. The credibility evaluation of the calculation model is High (H) using the established fuzzy comprehensive evaluation, analytic hierarchy process and adaptive neuro-fuzzy inference system (fuzzy AHP-ANFIS) method, and the credibility of the results of the established computational model is verified.