Radionuclides alkali metals

As for their stable analogs, the adsorption of radionuclides may depend on experimental conditions. Any variation results from the chemistry of the element, not form its radioactive nature. For example, the adsorption of the alkali metal cesium is largely independent of pH, whereas pH dependence is to be expected for oxyanions (Chapter 5, this volume) such as selenite and selenate and for transition metals such as nickel, silver, and palladium. 

The only fault which would result in a radionuclide release is the main steam line break. The only releases of significance are iodine and the alkali metals that become airborne and are released to the environment as a result of the accident. Noble gases are also released to the environment, but their impact is secondary because any noble gases entering the secondary side during normal operation are rapidly released to the environment. 

Although the analysis demonstrates that no fuel rods are damaged, and that there is therefore no release to the reactor coolant, a conservative analysis has been performed assuming 10 percent of the rods are damaged. Activity carried over to the secondary side because of primary-to-secondary leakage is available for release to the enviromnent viathe steam line safety valves or the power-operated relief valves. The significant radionuclide releases due to the locked rotor accident are the iodines, alkali metals and noble gases. 

Radioisotopes of some metals are naturally present in soils. The most conmion is potassium-40, with a natural abundance of 0.012% and a half-life of 1.28 x 10 years. Since potassium is an essential nutrient, the average content of the human body is 4000 Bq. Similarly, another alkali earth metal, rubidium, has a natural radioisotope, Rb, with a half-life of 4.75 x 10 years and accounts for about 600 Bq hi the human body. Other natural radionuclides, such as - U and whose distribution and relative abundance may be altered by mining and other human activity, may contribute significantly to radiation dose but are not... 

Most metals except the alkalis and alkaline earths can be electroplated at the cathode with suitable applied voltage from acid solutions. Relatively early experience with electrodeposition of various metals is summarized in Fig. 3.9. The process typically is applied for carrier-free or low-concentration samples to prepare sources for alpha-particle spectral analysis. It is also useful for depositing thin sources for counting radionuclides that emit beta-particles with low maximum energy. 

As we have accumulated more data on scintillators it has proven useful to group radionuclides of elements in a given region of the periodic chart. This approach can save considerable time in designing scintillator formulations for additional radionuclides. This is demonstrated in the RESULTS AND DISCUSSION section in which radionuclides are divided into four groups (3.1) Alkali and Alkaline Earth Elements, (3.2) Transition Metal and Lanthanide-Series Elements, (3.3) Actinides, and (3.4) Non-Metals and Heavy Metals. 

---