RADON CONCENTRATION IN THE AREA OF WASTE ROCK DUMPS, BROD, CR-CASE STUDY.

There are ~7000 mining waste storage facilities including waste rock dumps in the Czech Republic. One of the radiation protection present subjects is a health impact estimation of the huge mass of material in waste rock dumps left after uranium mining. In this document are presented selected results of waste rock dump long-term monitoring in the area of shaft No. 15 (Pribram, CR) and its estimated health impact to the representative person in a village Brod. The external irradiation was estimated based on in situ gamma spectrometry measurement results and on a Monte Carlo model and it turned out to be negligible (tens µSv), while the internal irradiation (RAMARN, ALGADE Environmental and RAMONIS detection systems) is more significant. The estimated total annual effective dose for representative person is mainly caused by indoor radon inhalation. The maximum outdoor radon concentration in summer season was measured during night hours between 9 p.m. and 7 a.m. and could reach thousands Bq/m3. The average indoor concentration measured in randomly selected houses was 450 Bq/m3. The radon exhalation rate was 35-40 mBq m-2 s-1.

Evaluation of human body irradiation caused by radionuclides deposited in the filtration unit of gas mask.

Radioactive aerosol particles represent a serious risk for people facing the consequences of nuclear accident of any kind. The first responders to emergency situation need to be protected by personal protective equipment which includes radiation protection suit supplemented with gas mask. The purpose of this work is to estimate the dose to the organs of responder's body as a result of radionuclide deposition in the filtration unit of the gas mask. The problem was analyzed using Monte Carlo simulations. The dose absorbed by different organs for five representative radionuclides and the dose distribution over the responder's body are presented in this paper. Based on presented MC simulations, we suggest a method of evaluating the irradiation of the responder by the radionuclides deposited in the filtration unit of the gas mask.

Determining radioactive aerosol concentrations using a surface radioactive contamination measurement device.

For experiments with dispersed radioactive aerosols in a radon-aerosol chamber (RAC), it is desirable to know the activity of the radioactive aerosols applied in the RAC. A COLIBRI TTC survey metre with an SABG-15+ probe (Canberra, USA) was purchased for this purpose. The probe is designed for surface contamination measurements, and it is intended to measure the activity of aerosols deposited on the filters during experiments in the RAC. Since the probe is calibrated in a different geometry, its response in the authors' experimental geometry was simulated by a Monte Carlo method. The authors present a Monte Carlo model using MCNPX and an experimental verification of this probe model.

Revealing the hidden faults in the SE flank of Mt. Etna using radon in-soil gas measurement.

Although there are many methods for investigating tectonic structures, many faults remain hidden, and they can endanger the life and property of people living along them. The slopes of volcanoes are covered with such hidden faults, near which strong earthquakes and gas releases can appear. Revealing hidden faults can therefore contribute significantly to the protection of people living in volcanic areas. In the study, seven different techniques were used for making measurements of in-soil radon concentrations in order to search for hidden faults on the SE flank of the Mt. Etna volcano. These reported methods had previously been proved to be useful tools for investigating fault structures. The main aim of the experiment presented here was to evaluate the usability of these methods in the geological conditions of the Mt. Etna region, and to find the best place for continual radon monitoring using a permanent station in the near future.