Uncertainty quantification study on gas phase iodine release from Fukushima Daiichi accident in unit 3

Environmental iodine as a natural iodine intake in humans and environmental pollution index: a scientometric and updated mini review

Although almost a third of the world's population is exposed to iodine deficiency (ID), and supplementation programs such as enriching table salt have been carried out or are being carried out at the global and national level, in many regions of the world, people are facing an increase in iodine intake, which is mainly due to the presence of large amounts of iodine in water, soil, agricultural products, or high consumption of seafood. Published articles were indexed in the Scopus database (from 2000 to 1 April 2023) were reviewed and analyzed by VOSviewer software. The results showed the growing interest of researchers over the last 20 years in environmental iodine intake. The results of this study can have a significant impact on the planning and policy-making of relevant officials and communities to supply the needed iodine.

An experimental, computational, and uncertainty analysis study of the rates of iodoalkane trapping by DABCO in solution phase organic media

NMR spectroscopy was used to measure the rates of the first and second substitution reactions between iodoalkane (R = Me, 1-butyl) and DABCO in methanol, acetonitrile and DMSO. Most of the reactions were recorded at three different temperatures, which permitted calculation of the activation parameters from Eyring and Arrhenius plots. Additionally, the reaction rate and heat of reaction for 1-iodobutane + DABCO in acetonitrile and DMSO were also measured using calorimetry. To help interpret experimental results, ab initio calculations were performed on the reactant, product, and transition state entities to understand structures, reaction enthalpies and activation parameters. Markov chain Monte Carlo statistical sampling was used to determine a distribution of kinetic rates with respect to the uncertainties in measured concentrations and correlations between parameters imposed by a kinetics model. The reactions with 1-iodobutane are found to be slower in all cases compared to reactions under similar conditions for iodomethane. This is due to steric crowding around the reaction centre for the larger butyl group compared to methyl which results in a larger activation energy for the reaction.

Analysis of volatile nuclides' behavior in the atmosphere released due to the FDNPP accident

The volatile nuclides, 131I, 132I, and 132Te, which were released in large quantities during the early stage of the Fukushima Dai-ichi Nuclear Power Plant accident, are the most dominant ones in determining the impact on the public and the environment. Since the behavior of these nuclides in the environment and their effects on human health differ depending on their physicochemical forms, it is necessary to understand more about the release fraction and the deposition process of each form. In this study, a behavior model was developed to calculate physical and chemical processes of organic, inorganic, and particulate 131I and 132I, and gaseous and particulate 132Te. This behavior model was used to estimate the physicochemical composition of iodine at the time of release, the 132Te/132I activity ratio at the time of release, and the dry deposition velocity of 132Te. The estimation was performed for five plumes transported during the period from March 14 to 21, 2011, and the estimated values were obtained by comparing with the values measured in previous studies. As a result of the estimation, the organic iodine fraction at the time of release was estimated to be 0.1 or less for most plumes, while a significantly higher value of 0.3 was estimated for the plume released in the night of March 14. This result implied that the possibility of formation and release of organic iodine in the liquid phase in Unit 3, which was considered to be the source of this plume. As for the 132Te/132I ratio at the time of release, it was estimated to be about 0.3-0.4 for most plumes, while it was about 1 in the plume released in the early morning of March 15, which is consistent with the release process in Unit 2 on the night of 14 and early morning of the 15. In addition, a remarkably high dry deposition velocity of 132Te was estimated in this plume, which was consistent with the existence of radiocaesium-bearing microparticles (CsMP) with a particle size of a few micrometers that had been found to be specific to this plume.