Iodine compounds, leach

Leach Resistance of Iodine Compounds in Portland Cement... 

Previous Studies. Clark (20), Morgan et al. (21), Partridge and Bosuego (22), and the Pacific Northwest Laboratory (PNL) (23-27) have performed leaching studies on selected iodine compounds in cement, evaluating various cement additives or coatings. 

Our studies have shown that there is a considerable difference in stability and leach resistance among the various iodine compounds in Portland III cement. Of the compounds examined, Agl had the best leach resistance followed by AgZI, 63(103)2, Ca(I03)2 ... 

The data obtained in the measurements showed that about 1% of the iodine inventory of the central fuel module reached the blowdown suppression tank, while only 0.23% of the cesium inventory appeared there. These data and those taken from the simulated broken line indicated that cesium deposited in this line more readily than iodine the reverse situation occurred in the upper plenum of the reactor pressure vessel. Here, almost no cesium was detected on the deposition coupons while iodine was present in amounts similar to those in the line of the low-pressure injection system. Besides iodine, silver was found on the upper plenum coupons in equivalent amoimts in addition, the iodine deposited on these coupons could not be leached by water, indicating that it was present there as an insoluble compound. From these data it was concluded that fission product iodine was transported out of the reactor core as Agl, rather than as Csl. Formation of Agl as the main iodine compound deposited in the upper plenum of the reactor pressure vessel is a behavior markedly different from that observed in other in-pile experiments and in the TMI-2 post-accident investigations. The reason for this behavior was assumed to be the low concentrations of both cesium and iodine present in the low-bumup fuel, which resulted in a very high stoichiometric excess... 

Vanadium ores are heated to high temperatures with sodium chloride in air to obtain water-soluble sodium vanadate, which is then leached with dilute acids so that a vanadium oxide can be obtained. The precipitate is dissolved in a sodium carbonate solution and ammonium chloride is added to precipitate NH4VO3. Intense heating of NH4VO3 causes it to decompose to V2O5, which is the commercial vanadium compound [13]. Vanadium metal can be purified by several methods including iodine refining [13]. 

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