Akademik Veri Yönetim Sistemi
Tezin Türü: Doktora
Tezin Yürütüldüğü Kurum: Orta Doğu Teknik Üniversitesi, Türkiye
Tezin Onay Tarihi: 2014
Tezin Dili: İngilizce
Öğrenci: Latife Özge Ünver
Eş Danışman: SÜLEYMAN GÜRDAL TUNCEL, Süleyman Tuncel
Özet:A dynamic dose model has been developed to estimate radiation doses and stochastic risks due to atmospheric discharges of radionuclides in the case of a nuclear reactor accident. In addition to individual doses from different pathways for different age groups, collective doses and stochastic risks can be calculated by the model. The model can be coupled to any long-range atmospheric dispersion model which can calculate radionuclide concentrations in air and on the ground at predetermined time intervals or measurement data. Since the Chernobyl accident, there had been an increase in real world data to assess the capabilities of software, which are developed to calculate radionuclide concentrations in the environment and doses to human. Therefore, data related to Chernobyl accident was used to validate the developed software. The validated software was then used to calculate radiological consequences in the case of hypothetical severe accidents at Akkuyu and Sinop NPPs in Turkey. The accident scenario was based on Fukushima Daiichi NPP accident. The newly developed software was run for different release times, and it was turned out that meteorological pattern as well as vegetation cycles of the plants were influencing doses to humans. The doses incurred due to a severe accident at Akkuyu NPP were calculated as 3.374 mSv 1 year after the accident, and the lifetime doses will be 9.706 for adults having average habits; the doses in the case of Sinop NPP accident have been found out to be more than that of Akkuyu NPP accident. Cs-134, Cs-137 and I-131 were identified as the most dose contributing isotopes, and cereals, cow milk, chicken, fruits, lamb, beef, fruit vegetables and root vegetables were the most dose contributing foods respectively. For the maximum deposited grit found out as a result of simulation of Akkuyu NPP accident, and for the related parameters of most dose contributing isotopes and foodstuffs, uncertainty analysis was performed by LHS to predict uncertainties in the doses and activity concentrations. Furthermore, sensitivity analysis was also conducted by again LHS of the aforementioned parameters and the outputs were processed by correlation techniques to find out most influencing parameters on lifetime and short-term doses. It can be concluded that soil-plant transfer factors for Cs have a big influence on the lifetime dose results, feed-animal transfer factor for Cs for cow milk and reduction factors for external radiation, beef and grain consumption amounts have also the high effect on lifetime doses. For the short term doses, cow milk transfer factor for iodine and interception factor for the grass are also influential parameters.