Search Results
Abstract
Aerosol-size distributions of218Po were determined for the accelerator tunnel air sampled during machine operation and for the basement air of a concrete building, where the number and the size distribution of non-radioactive aerosols are greatly different from each other. The218Po distributions depended very much on the size distributions of ambient non-radioactive aerosols, and could be well explained by an attachment model of218Po to ambient non-radioactive aerosols.
Abstract
A number of samples of whole blood, and urine from diabetic and non-diabetic persons have been analyzed for their trace elemental contents using the proton-induced X-ray emission. The elemental contents of the diabetic and non-diabetic samples are compared.
Abstract
Some heavy metal ferrocyanides were prepared and their selectivity towards cesium was investigated. Many were found to have good ion exchange properties and some can be easily prepared in a granular form suitable for the use in a packed column operation. The ferrocyanides show high cesium uptake in various simulated processing solutions relevant to the treatment of radioactive wastes. The amount of cesium sorbed by these hexacyanoferrates exceeded 99%. They also possess a high selectivity for cesium in solutions of high salt concentration. Desorption of the sorbed cesium at various nitric acid concentrations have been investigated and it is concluded that cesium is eluted by a chemical reaction step as a consequence of the oxidation of the ferrocyanides. It has also been observed that ferrocyanides degrade in solutions of low pH.
Abstract
The preparation of novel types of inorganic ion-exchangers, titanium and zirconium phosphates and their ion-exchange properties towards strontium ions, are reported and discussed. Ti(HPO4)2·2H2O is shown to be very stable to hydrolysis and to have high exchange capacity in strongly acid medium. In the case of zirconium phosphate, the titration curves with alkaline earth metal hydroxides are strongly affected by hydrolysis of the exchanger and precipitation of insoluble phosphate. The degree of conversion of the exchanger at which phosphate precipitation begins was found to be 80% for Sr2+. The comparison of Ti(HPO4)2·2H2O with the corresponding zirconium phosphate dihydrated phase suggests that the former possesses a lattice structure different from that reported for the monohydrated exchanger.
Abstract
Preparation conditions of composite ion-exchanger based on stannic molybdophosphate (SMP) and poly-acrylamide (PAA) have been described. Batch distribution coefficients for some ions were investigated at 25 °C. Sodium ion exchange capacity and breakthrough curves of cesium and strontium ions have also been determined. The results obtained from the experiments showed that the selectivity of SMP-PAA for cesium and strontium was greater than for other ions. Adsorption amounts of both ions were higher than 99% in demineralized water and their uptake rate were relatively rapid.
Summary
This study deals with the treatment of Cs+and Sr2+by using natural clinoptilolite from Ardakan region (Yazd province) of Iran and its relevant zeolite P as well as the vitrification process for immobilizing the Cs and Sr radionuclides in borosilicate glass matrices. The evaluation of various samples was carried out using X-ray techniques (XRF, XRD) as well as atomic absorption spectroscopy (AAS) for leaching experiments.
Summary
Samples of a new inorganic ion-exchanger thorium tungstophosphate have been prepared under various conditions. The ion exchange capacity, IR, XRD, thermogravimetry and sorption of the radionuclides have been studied. Separation of Sr-Nd, Sr-Ce, Cr-Mo and Cs-Nd have been developed on columns of this ion-exchanger.
Abstract
A worldwide radionuclide network of 80 stations, including 40 with noble-gas-detection capability forming part of the International Monitoring System, has been designed to monitor compliance with the Comprehensive Nuclear-Test-Ban Treaty. Pending entry into force of the Treaty, the certified stations are operating provisionally and so far an experience of over 100 station-years has been acquired for particulate stations. Noble gas systems are still under testing, though the operational experience is fast growing. A maintenance strategy is being developed on the basis of the experience acquired so far and the analysis of equipment failure.
Abstract
The scientific activity and organisation of the Radioactivity Group, Atomic Physics Division, Physikalisch-Technische Bundesanstalt, Braunschweig, FRG is discussed.
Abstract
Coals mined in some regions of the Transdanubian Middle Mountains in Hungary have elevated concentrations of natural radionuclides as238U,226Ra, etc. Therefore, coal slags and ashes used for insulation of the school buildings may lead to high dose contributions on the students. In the city of Tatabánya one school was found where the external dose rates in the classrooms were of 500–900 nGy/h. In spite of the high external dose rates, the radon concentrations measured were small usually less than 100 Bq/m3.
