Fission product iodine, chemistry

Castleman, A. W. jr., Tang, I. N., Munkelwitz, H. R. The chemical states of fission product iodine emanating into a high temperature aqueous environment. J. Inorg. Nucl. Chemistry 30, 5-13 (1968)... 

The extraction process for radioisotopes is a combined chemical/distillation process in which the noble gases and iodine are first condensed from the target fill gas. Next, the UO2 fuel and fission products are dissolved from the inside of the target in an acidic solution and a wet chemistry process is used to selectively precipitate isotopes of interest. The precipitates are further washed, filtered, redissolved and purified. Finally, the isotope solution is prepared for shipment. 

This report examines the severe accident sequences and radionuclide source terms at the Sizewell pressurised water reactor with a piestressed concrete containment, the Konvoi pressurized water reactor with a steel primary contaimnent, the European Pressurised water Reactor (EPR) and a boiling water reactor with a Mark 2 containment. The report concludes that the key accident sequences for European plant designs are transient events and small loss-of-coolant accidents, loss of cooling during shutdown, and containment bypass sequences. The most important chemical and transport phenomena are found to be revaporisation of volatile radionuclides from the reactor coolant system, iodine chemistry, and release paths through the plant. Additional research is recommended on release of fission products from the fuel, release of fission products from the reactor coolant system, ehemistry of iodine, and transport of radionuclide through plants. 

Summarizing these crystal chemistry considerations one can conclude that the fission products firmly fixed in the fuel are those with higher atomic charges and of dimensions compatible to those of the matrix lattice. Neutral atoms or monovalent fission products, both of which having larger dimensions (e. g. fission product noble gases as well as iodine), are more mobile in the fuel, in particular when they... 

Bowsher, B. R., Henshaw, J. G., Newland, M. S. The kinetics of reaction between iodine vapour and bulk-material aerosols. Proc. 3. CSNI Workshop on Iodine Chemistry in Reactor Safety, Tokai-mura, Japan, 1991 Report JAERI-M 92-012 (1992), p. 165-180 Bowsher, B. R., Nichols, A. L. High-temperature studies of simulant fission products. Part IV Interaction of caesium iodide with boric acid over the temperature range 400 to 1000 °C. Report AEEW-R 1973 (1985)... 

Beahm, E. C., Weber, C. F., Kress, T. S., Shockley, W. E., Daish, S. R. Chemistry and mass transport of iodine in containment. Proc. 2. CSNI Workshop on Iodine Chemistry in Reactor Safety, Toronto, Can., 1988 Report AECL-9923 (1989), p. 251—266 Beard, A. M., Bowsher, B. R., Nichols, A. L. Interaction of molecular iodine vapour with silver—indium—cadmium aerosol. Proc. International Symposium Severe Accidents in Nuclear Power Plants, Sorrento, Italy, 1988 IAEA-SM-298/108, Vol. 2, p. 201—213 Bell, J. T. Chemistry of iodine and cesium, in M. Silberberg (Report Coordinator) Technical Bases for Estimating Fission Product Behavior during LWR Accidents. Report NUREG-0772 (1981), Chapter 5... 

Furrer, M., Buhler-Gloor, T. Revolatilisation of fission products, especially iodine, from water phases during evaporation to dryness. Proc. 2. CSNI Workshop on Iodine Chemistry in Reactor Safety, Toronto, Can., 1988 Report AECL-9923 (1989), p. 185—193... 

For the containment the objective is to study the fission product chemistry and especially iodine radiochemistry in the sump water and atmosphere and the effect of p ts in the "dirty" chemical conditions of a reactor accident. 

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