Iodosodalite Waste Forms from Low-Temperature Aqueous Process

ABSTRACTNuclear energy is one option to meet rising electricity demands, although one concern of this technology is the proper capture and storage of radioisotopes produced during fission processes. One of the more difficult radioisotopes is 129 I due to its volatility and poor solubility in traditional waste forms such as borosilicate glass. Iodosodalite has been previously proposed as a viable candidate to immobilize iodine due to high iodine loading and good chemical durability. Iodosodalite was traditionally synthesized using solid state and hydrothermal techniques, but this paper discusses an aqueous synthesis approach to optimize and maximize the iodosodalite yield. Products were pressed into pellets and fired with glass binders. Chemical durability and iodine retention results are included.

Pendred Syndrome in Two Galician Families: Insights into Clinical Phenotypes through Cellular, Genetic, and Molecular Studies

Context: We studied two families from Galicia (northwest Spain) with Pendred syndrome (PS) and unusual thyroid phenotypes. In family A, the proposita had a large goiter and hypothyroxinemia but normal TSH and free T3 (FT3). In family B, some affected members showed deafness but not goiter. Objective: Our objective was to identify the mutations causing PS and molecular mechanisms underlying the thyroid phenotypes. Interventions: Interventions included extraction of DNA and of thyroid tissue. Patients: Propositi and 10 members of the two families participated in the study. Main Outcome Measures: Main outcome measures included SLC26A4 gene analysis, deiodinase activities in thyroid tissue, and c.416–1G→A effects on SLC26A4 splicing. In addition, a primary PS thyrocyte culture, T-PS2, was obtained from propositus B and compared with another culture of normal human thyrocytes, NT, by Western blotting, confocal microscopy, and iodine uptake kinetics. Results: Proposita A was heterozygous for c.578C→T and c.279delT, presented with goiter, and had normal TSH and FT3 but low FT4 attributable to high type 1 and type 2 iodothyronine deiodinase activities in the goiter. Propositus B bore c.279delT and a novel mutation c.416–1G→A; some deaf relatives were homozygous for c.416–1G→A but did not present goiter. The c.279delT mutation was associated with identical haplotype in the two families. T-PS2 showed truncated pendrin retained intracellularly and high iodine uptake with low efflux leading to iodine retention. Conclusions: c.279delT is a founder mutation in Galicia. Proposita A adapted to poor organification by increasing deiodinase activities in the goiter, avoiding hypothyroidism. Lack of goiter in subjects homozygous for c.416–1G→A was due to incomplete penetrance allowing synthesis of some wild-type pendrin. Intracellular iodine retention, as seen in T-PS2, could play a role in thyroid alterations in PS.

An Investigation of the Stability of Double Fortified Salt during Storage and Distribution in Nigeria

Double fortified salt prepared with various formulations of iodine and microencapsulated iron has been investigated for stability in a five-month period, under actual field conditions of storage and distribution, in the south coastal and north highland regions of Nigeria. A control of iodated salt and fifteen 500g sample packets of double fortified salt, prepared in duplicate, were sealed in polyethylene bags. These samples, and a datalogger for monitoring temperature and humidity, were packaged into a typical bundle which was overwrapped with polyethylene film and inserted into the distribution network starting from a salt manufacturer's facility to the consumer. Iodine retention values of up to 79% were obtained when iodated salt was used and 64% when potassium iodide premix was used. Less than 20% of the ferrous iron was oxidized to ferric iron, and about 25% of the iron in formulations with sodium ferric EDTA (NaFeEDTA) reduced to ferrous iron. Double fortified salt with ferrous fumarate was generally more stable than those prepared with the other iron premixes. The polyethylene film overwrap of salt packs in the bundles provided a significant protection from ambient humidity. Iodine and the ferrous iron were protected in salt, double fortified with iodine and microencapsulated iron, during distribution and retail in typical tropical conditions in Nigeria's coastal and northern highlands.

Emergency exhaust system’s efficiency measurements for iodine removal at PARR-1

The emergency exhaust system of the Pakistan Research Reactor-1 (PARR-1) in corporates charcoal bed filters for the removal of radioiodine from exhaust gases in case of an emergency involving the release of radioiodine. The filters adsorb radioiodine. Testing of the filters is necessary so as to assess their iodine retention efficiency, if they are to meet regulatory requirements. The retention efficiency of our filters has been measured and found to be 99.1%. This value is higher than the value of the activated charcoal filter efficiency (99%) employed to determine the source term for release through emergency exhaust with filtration, for dose calculations. In this paper, the procedure for testing the efficiency of charcoal filters has been discussed and results obtained presented.