4,430 research outputs found
Immobilization of Fission Iodine by Reaction with a Fullerene Containing Carbon Compound and Insoluble Natural Organic Matrix
The recovery of iodine released during the processing of used nuclear fuel poses a significant challenge to the transmutation of radioactive iodine. During the first year of this program we have examined the potential of Fullerene Containing Carbon compounds (FCC) developed by KRI, and natural organic matter (NOM) as sorbents for iodine released during the reprocessing of nuclear fuel. This work involved the development of bench-scale testing of the FCC and NOM material in a simulated process off-gas environment.
During the first two quarters of this program we explored various analytical methods available for measurement of iodine, iodide, and iodate. We reproduced an analytical method proposed by Mishra et al., 2000 for measurement of trace levels of iodide and iodine in aqueous solution. Iodine or hypoiodic acid reacts with N,N-dimethylanaline to form p-iododimethylaniline. Iodide can be measured after selective oxidation of iodide with 2-iodosobenzoate to produce active iodine that is subsequently reacted with N,Ndimethylaniline. The product p-iodo-N,N-dimethylaniline can be quantified by GC/MS. This method gave excellent results in dilute aqueous solutions however; we did encounter some interference in the presence of NOM. The method should still be useful for quantifying low levels on iodine released by FCC or other sorbent materials
Federated Statistical Analysis: Non-parametric Testing and Quantile Estimation
The age of big data has fueled expectations for accelerating learning. The
availability of large data sets enables researchers to achieve more powerful
statistical analyses and enhances the reliability of conclusions, which can be
based on a broad collection of subjects. Often such data sets can be assembled
only with access to diverse sources; for example, medical research that
combines data from multiple centers in a federated analysis. However these
hopes must be balanced against data privacy concerns, which hinder sharing raw
data among centers. Consequently, federated analyses typically resort to
sharing data summaries from each center. The limitation to summaries carries
the risk that it will impair the efficiency of statistical analysis procedures.
In this work we take a close look at the effects of federated analysis on two
very basic problems, nonparametric comparison of two groups and quantile
estimation to describe the corresponding distributions. We also propose a
specific privacy-preserving data release policy for federated analysis with the
-anonymity criterion, which has been adopted by the Medical Informatics
Platform of the European Human Brain Project. Our results show that, for our
tasks, there is only a modest loss of statistical efficiency
Immobilization of Fission Iodine by Reaction with a Fullerene Containing Carbon Compound and Insoluble Natural Matrix
Observations related to the oxidation of iodide to iodine (I2) or hypoiodic acid (HIO) by MnO2 were continued. The formation of triiodide presumable involves the adsorption of iodide onto the MnO2 surface (perhaps displacing a surface hydroxyl group). The iodide should be subsequently oxidized and released back into solution as IOH or I2, which rapidly forms I3 -. The kinetic data has been modeled as a first order process. First order rate constants have been obtained for the formation of iodine in the presence of MnO2. The increase in iodide oxidation rates with MnO2 concentration is evident in the data. The reaction rate increases with iodide concentration although the dependence is not first order (an order of 1.4 appear to fit the data). The oxidation rate also increases with temperature and has a apparent activation energy of 16.2 kJ/mol
Immobilization of Fission Iodine by Reaction with a Fullerene Containing Carbon Compound and Insoluble Natural Matrix
The stability of the association of iodine with FCC and NOM products were studied. Product distributions for the various matrices under various reaction conditions were examined in order to maximize the binding of iodine. The recovery of the iodine from the sequestration matrices was also examined, along with the conversion of the iodine to matrices more suitable for geological storage and/or use as transmutation targets.
The following are the specific research objectives and goals: Develop bench-scale experimental set-up and procedures for simulating plutonium extraction process (PUREX) head-end vapor phase. Develop experimental procedures for evaluating iodine sequestering methods using bench-scale procedures. Develop FCC bearing material as potential iodine sequestration matrix. Determine binding of iodine to FCC and NOM. Examine alternate iodine sequestration matrices using techniques developed for FCC and NOM studies. Examine the effect of reaction conditions on binding. Elucidate the nature of the reaction products (volatile, hydrophobic, soluble, insoluble). Develop methodology and host matrix for converting sequestered iodine to solid matrix for evaluation as transmutation target and/or disposal matrix. Examine recovery of iodine from sequestration matrices
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