Activity Concentrations Of Nuclides Research Articles

Modeling: Activity Concentration of Radon, Thoron, and Their Decay Products in Closed Systems

The article presents a model for simulating changes in the activity concentration of radon and thoron as well as their progeny in closed or poorly ventilated systems. A system can be considered closed when a stream of radon and thoron flows into a space, but nothing comes out. It was also assumed that there may be devices or installations with a filtering system that would reduce the concentration of radon and thoron decay products. These assumptions may, therefore, correspond to a situation in which, in an isolated chamber, the calibration of radon hazard-monitoring devices is carried out, and nuclides are supplied from an emanation or flow through sources or well-isolated spaces in an environment where the source of nuclides is, for example, radon and thoron exhalation. The differential equations were formulated on the basis of the assumption that the activity concentration of radionuclides of concern in the space is uniform. The equations do not consider possible losses due to diffusion or the inertial or gravitational deposition of aerosols. If these phenomena have a limited impact on changes in the activity concentration of nuclides, the solutions provided may be used to simulate the activity concentration of radon and thoron and their decay products in any confined space assuming different boundary conditions.

Assessment of Radiological Air Contamination for Selected Places at Al-Tuwaitha Nuclear Site during Winter and Spring

This study presents the results of atmospheric particulates sampling using high volume air sampler for selected places at Al Tuwaitha nuclear site. The collected samples were analyzed for gross alpha /beta radioactivity using Ludlum model 3030 and measurement particles activity in Al Tuwaitha nuclear site and the surrounding areas for the period from 28/12/2016 to 13/4/2017.The measurement of activity concentrations ranged from (0.42±0.03 to 4.18±0.13) Bq/m3 for alpha particles and from(0.93±0.06 to 9.21±0.26) Bq/m3for beta particles. The activity concentration of nuclides inversely proportional with air temperature and wind speed while humidity is directly proportional with it. Highest value of activity concentration has been found at(Near nuclear and radiation safety directorate/ In the center of planning department/T9)while the lowest value has been found at (the right side of Nuclear application and researches directorate / building 61/T42). The results of this study show that the region has natural nuclides which are the daughters of the two decay series, namely the thorium and the uranium series. In both cases, it is a radioactive Radon isotope which can escape from the soil and ascend into the air.

210Po and 210Pb bioaccumulation and possible related dose assessment in parasol mushroom (Macrolepiota procera)

Presented are results of a study on accumulation and distribution of 210Po and 210Pb in the fruitbodies of parasol mushroom (Macrolepiota procera) and risk to human consumer due to exposure from highly radiotoxic decay particles emitted by both radionuclides. Mushrooms were collected from 16 forested places in central and northern regions of Poland. Activity concentrations of 210Po and 210Pb were determined after radiochemical separation of nuclides and subsequent measurement using validated method and alpha spectrometer. Results showed on spatially heterogeneous distribution of the 210Po and 210Po activity concentrations in M. procera and two interpolation maps were prepared. Activity concentrations of nuclides in dried caps of M. procera were in the range from 3.38 ± 0.41 to 16.70 ± 0.33 Bq∙210Po ∙kg−1 and from 5.11 ± 0.21 to 13.42 ± 0.30 Bq∙210Pb ∙kg−1. Consumption of M. procera foraged in central and northern Poland should not contribute significantly to the annual effective radiation doses from 210Po and 210Pb due to amount of both nuclides accumulated by fungus in caps.

Analysis of natural radioactivity in Yatağan coal – fired power plant in Turkey

Use of the coal in order to generate electricity increases the exposure of people to radiation. In this paper, the activity concentrations of nuclides 226 Ra, 232 Th and 40 K in samples of coal and bottom ash from the Yatagan Coal–Fired thermal power plant determined using gamma ray spectrometer with a NaI(Tl) scintillation detector. The mean activity concentrations of 226 Ra, 232 Th, and 40 K in the coal were found to be 37.2±2.8 Bqkg -1 , 51.8±3.4 Bqkg -1 and 166.7±11.1 Bqkg -1 , respectively. Whereas in the bottom ashes, the concentrations of the corresponding radionuclides were found to be 62.2±5.6 Bqkg -1 , 87.4±5.9 Bqkg -1 and 221.0 ±12.5 Bqkg -1 , respectively. The findings show that bottom ashes show higher activity concentrations of related radionuclide to coal samples. The absorbed gamma dose rate in outdoor air DR OUT and annual effective dose rate (AED) from coal were calculated to define radiological risk. The average findings of annual effective doses were detected as 68.6±5.1 μSvy -1 and 110.3±11.2 μSvy -1 , respectively.

DÖME: revitalizing a low-background counting chamber and developing a radon-tight sample holder for gamma-ray spectroscopy measurements

There was an emerging need at the Nuclear Analysis and Radiography Department of the Centre for Energy Research, Hungarian Academy of Sciences, Budapest to be able to perform low level radioactivity measurements of various samples from in-beam activation and from environmental studies. Important aspects of reusing the low-background chamber called DOME, which had been unused for some years, were the development of an easily reusable radon-tight sample container and the setup of a measurement system capable of counting extended samples in close-in geometry. As a result of our efforts a special sample container made of HDPE (High-density Polyethylene) was developed, and it is proved that the probability of a radon loss larger than the 2 % of its radioactive decay constant is <95 %. Due to the lack of reference samples, containing the same radionuclides as the unknown sample, the absolute method of measuring the activity concentration of nuclides in the sample had to be applied, which implied the reliable determination of the full-energy peak efficiency. A method called efficiency transfer combined with the correction for true coincidence summing effects is proven to be providing appropriate results and applied.

Natural radioactivity of paleozoic and mesozoic sedimentary rocks from the Upper Silesian Coal Basin borders (Poland) — in situ gamma ray measurements

Sedimentary rocks from the borders of the Upper Silesian Coal Basin are the most popular origin of building materials in whole Silesia region. In situ gamma ray spectrometry was used to determine the activity concentration of nuclides from U series, Th series and potassium 40K in almost every kind of sedimentary rocks outcropping in the studied region. Measured activity concentration of particular nuclides such as 40K, U series, and Th series are mostly not higher than average activity concentrations of these nuclides in the continental crust. However, there are some significant exceptions such as clays from Blanowice and Krasiejow. In spite of that there isn’t any reason to stop using these rocks as building or other industrial material sources.