Study of natural radionuclides and its radiation hazard index in Malaysian building materials

The main component of most building materials in Malaysia is rock. All rocks are known to contain natural radionuclides such as ²³⁸U and ²³²Th series as well as ⁴⁰K. In order to estimate the radiological impact to the dweller, the level of radionuclides present in various building materials available in Malaysia were analyzed using γ-spectrometry. The radiation hazard indexes were calculated based on the above results. The results showed that the activity concentration of natural radionculides ²³⁸U, ²³²Th, ⁴⁰K was between 19.0–42.2 Bq/kg, 16.5–28.8 Bq/kg and 243.3–614.2 Bq/kg, respectively. On the whole, the radionuclides concentration was still below the global average of 50 Bq/kg, 50 Bq/kg and 500 Bq/kg for ²³⁸U, ²³²Th, and ⁴⁰K, respectively The radiation hazard indexes of the building materials were also lower than the maximum value suggested.     

Concentration of natural radionuclides in various types of building materials in Slovakia

The building materials and products whose content of natural radionuclides are contributors to the radiation exposure of the population. In this study several types of building materials used for construction of living buildings in Slovakia were examined. The concentrations of natural radionuclides (²²⁶Ra,²³²Th and⁴⁰K) were determined by -ray spectrometry with an HPGe detector. In the second part of the work, sixty samples of building products (panel), used for dwelling construction in several towns in Slovakia, were analysed. The concentration of natural radionuclides and the radium equivalent activity content in the inner-and outerside of the wall were estimated. The results were used for the calculation of the annual mean effective photon dose rates, by the model and calculation procedure of KRISIUK and KARPOV.     

Assessment of natural radionuclide enrichment and radiation hazard from building materials in Kannur District,Kerala

Journal of Radioanalytical and Nuclear Chemistry - The activity concentrations of natural radionuclides from the 238U and 232Th series and singly occurring radionuclide 40K have been assessed in...     

Radioactivity of building materials in Serbia and assessment of radiological hazard of gamma radiation and radon exhalation

Journal of Radioanalytical and Nuclear Chemistry - This paper presents a gamma spectrometric analysis of 47 samples of building materials produced and used in Serbia. Based on the measured activity...     

Concentration of radon precursors in some malaysian building materials

Five types of building material of different quality and from different sources were analyzed for uranium and thorium using instrumental neutron activation analysis /INAA/. The concentration of thorium was found to be about 3–5 times higher than uranium while the activities were about the same. The total activities of both elements was found to be between 1–4 pCi g^–1.     

Non-destructive measurements of natural radionuclides in building materials for radon entry rate assessment

Journal of Radioanalytical and Nuclear Chemistry - To control the specific activity of 226Ra in building materials of operated buildings, a non-destructive in situ method consisted in measurements...     

Natural radioactivity and indoor radiation measurements in buildings and building materials in Gobichettipalayam town

Samples of natural and manufactured building materials used by the people of Gobichettipalayam town have been analyzed for ²²⁶Ra, ²³²Th and ⁴⁰K using gamma-ray spectrometry. Radium equivalent activity of the materials has been measured using the formula given by OECD and the geometric mean value of sand, clay and cements are found to be 53.53 Bq·kg⁻¹, 89.09 Bq·kg⁻¹ and 72.25 Bq·kg⁻¹, respectively. The radium equivalent activities obtained in the building materials are all well below the acceptable limit. The indoor gamma-dose has been measured using thermoluminescence dosimeters and it was found in the range of 1051.2–3946.0 μGy/year. The annual effective indoor gamma radiation dose to the people of Gobichettipalayam town has been found to be 0.8 mSv/y.     

Radiological assessment of natural radionuclides in soil from playgrounds in Southwestern Nigeria and evaluation of radiation dose

Journal of Radioanalytical and Nuclear Chemistry - The activity concentrations of natural radionuclides in soil from playground were determined by gamma spectrometry using NaI(Tl) detector. Annual...     

Natural radioactivity and radiation hazards in some building materials used in Isparta,Turkey

The activity concentrations of uranium, thorium and potassium can vary from material to material and it should be measured as the radiation is hazardous for human health. Thus first studies have been planned to obtain radioactivity of building material used in the Isparta region of Turkey. The radioactivity of some building materials used in this region has been measured using a γ-ray spectrometry, which contains a NaI(Tl) detector connected to MCA. The specific activity for ²²⁶Ra, ²³²Th and ⁴⁰K, from the selected building materials, were in the range 17.91–58.88, 6.77–19.49 and 65.72–248.76 Bq/kg, respectively. Absorbed dose rate in air (D), annual effective dose (AED), radium equivalent activities (Ra_eq), and external hazard index (H_ex) associated with the natural radionuclide are calculated to assess the radiation hazard of the natural radioactivity in the building materials. It was found that none of the results exceeds the recommended limit value.     

Decontamination of radionuclides on construction materials

A wide variety of materials can become contaminated by radionuclides, either from a terrorist attack or an industrial or nuclear accident. The final disposition of these materials depends, in large part, on the effectiveness of decontamination measures. This study reports on investigations into the decontamination of a selection of building materials. The aim has been to find an effective, easy-to-use and inexpensive decontamination system for radionuclides of cesium and cobalt, considering both the chemical and physical nature of these potential contaminants. The basic method investigated was surface washing, due to its ease and simplicity. In the present study, a basic decontamination formulation was modified by adding isotope-specific sequestering agents, to enhance the removal of cesium(I) and cobalt(II) from such construction materials as concrete, marble, aluminum and painted steel. Spiking solutions contained ¹³⁴Cs or ⁶⁰Co, which were prepared by neutron activation in the SLOWPOKE-2 nuclear reactor facility at the Royal Military College of Canada. Gamma spectroscopy was used to determine the decontamination efficiency. The results showed that the addition of sequestering agents generally improved the radiological decontamination. Although the washing of both cesium and cobalt from non-porous materials, such as aluminum and painted steel, achieved a 90–95 % removal, the decontamination of concrete and marble was more challenging, due to the porous nature of the materials. Nevertheless, the removal efficiency from 6-year-old concrete increased from 10 % to approximately 50 % for cobalt(II), and from 18 to 55 % for cesium(I), with the use of isotope binding agents, as opposed to a simple water wash.     

Sorption of radionuclides on natural materials

Information about the sorption of radionuclides on natural materials used for cementation of liquid radioactive wastes (RAW) is important for predictions of migration rates of radionuclides in the products of fixation. Cementation process for conditioning liquid RAW uses, besides cement, materials which improve quality of products. In Czechoslovakia technology among these materials are clinoptilolite tuffit, mordenite tuff, tobermorite and fly ash. Liquid RAW issued from nuclear power plants contains the principal radionuclides⁶⁰Co,¹³⁴Cs and¹³⁷Cs, therefore, a sorption study of these radionuclides was carried out. pH of liquid RAW was 12.5–13.7 and salt content ca. 200 g·dm^–3. Results of sorption are given by distribution coefficients. The best results for cesium in those pH region and salt content had mordenite tuff D_Cs=100 dm³·kg^–1 and the worst results had fly ash D_Cs=4.1 dm³·kg^–1. The best results for cobalt in those solutions had tobermorite D_Co=38 dm³·kg^–1 and the worst results had fly ash D_Co=6.9 dm³·kg^–1.     

An evaluation of ceramic materials for use in non-cooled low-flow ICP torches

The feasibility of a variety of potentially suitable ceramics for the segmented ICP torch is discussed. It is shown that available ceramics fail for a combination of three reasons: (i) thermal shock, (ii) absorption of rf field and (iii) corrosion. The best overall results have been obtained with boron nitride and silicon nitride coated with a 10 μm layer of silicon carbide, but even then the lifetime of the torch is only 90 h at 900 W rf power.     

Activity concentrations of radionuclides in soil samples along the coastal areas of Kerala,India and the assessment of radiation hazard indices

Journal of Radioanalytical and Nuclear Chemistry - In this study, radon (Rn) measurements were evaluated for the first time in the underground metro and Marmaray stations in Istanbul and the annual...     

Measurement of natural radioactivity and radiation hazards for some natural and artificial building materials available in Romania

As building materials are known to be the second source regarding high radon concentrations, it is very important to determine the amounts of natural radionuclides from every building material in use. In the present study the most frequently used Romanian natural (sand, gypsum, limestone) and artificial (portland cement, lime, clinker, electrofilter powder, fly ash, cement-lime plaster mortar, cement plaster mortar) building materials were analyzed. The absorbed dose rate and the annual effective dose equivalent rate for people living in dwelling buildings made of these building materials under investigation were also calculated. The analysis was performed with gamma-ray spectrometry, with two hyper-pure germanium detectors. The activity concentrations of natural radionuclides were in the ranges: 5.2–511.8 Bq kg^?1 for ²²⁶Ra; 0.6–92.6 Bq kg^?1 for ²³²Th and <1–1,720.7 Bq kg^?1 for ⁴⁰K, respectively. The radium equivalent activity in the fifty-one (51) samples varied from 9 to 603 Bq kg^?1. By calculating all the radioactivity indices (Ra_eq, H _ext, I _α, I _yr) it was found that all the building materials under investigation can be used to erect dwelling buildings. Except for sample SA6, SA7 and SA11 among the natural building materials and sample SG1, SG2, FAH1, CLM1, CM1 among the artificial building materials that are considered hazardous materials when are used in large quantities.     

Radiological hazard and radiogenic heat production in some building materials in upper Egypt</p> </p>

Summary Samples of limestone, sand, marble, clay brick, red brick, gypsum, Portland cement and white cement collected from upper Egypt used in building manufacturing have been analyzed for the natural radionuclides ²²⁶Ra, ²³²Th and ⁴⁰K usingg-ray spectrometry. The specific concentrations for ²²⁶Ra, ²³²Th and ⁴⁰K, ranged from 20-88, 13-115 and 54-304 Bq/kg, respectively. The average specific activities of these radionuclides were compared. Higher values of ²²⁶Ra and ²³²Th could be noticed in marble while that of ⁴⁰K was in red bricks. Radium equivalent activities, dose rate and the annual gonadal dose equivalents AGDE were calculated for the measured samples to assess the radiation hazard arising from using those materials in the construction of dwellings. The radioactive heat production values of the selected materials have also been determined. They vary from a minimum of 0.41 for white cement to a maximum of 5.52mW/m³ for marble samples. The calculated heat-production values are quite similar to those estimated in Corsica.</p> </p>     

Bismuth radionuclides in the natural background gamma radiation spectrum

The natural background gamma (NBG) spectrum was accumulated inside the laboratory, with 102.88 cm³ Ge(Li) detector, to investigate bismuth natural radionuclides in the energy range of 500–1700 keV. The relative intensities of identified²¹⁴Bi gamma lines were obtained from the spectrum. The results were in good agreement with that obtained from a source of a precise strength. Out of the 25 gamma lines of²¹⁴Bi, 19 lines were established including 6 lines observed for the first time in the NBG spectrum. Most of the gamma lines of²¹¹Bi and²¹²Bi were observed. Some of these lines are new.     

Permeability of polymer materials to compounds containing radionuclides

The permeability of rubber and PE gloves, PE bags and strippable PVC paint to HTO, Na¹²⁵I, H₂ ³⁵SO₄, H₃ ³²PO₄,¹⁴¹CeCl₃,⁸⁹SrCl₂, and,¹³⁷CsCl in aqueous solution was tested. All materials were permeable to HTO and Na¹²⁵I. Whereas rubber gloves were permeable the other materials were impermeable to H₂ ³⁵SO₄. The remaining radioactive compounds showed no penetration. The diffusion coefficients of the penetrating compounds were calculated on the basis of Fick's First Law for the respective materials. The permeability to Na¹²⁵I and HTO decreases in the order rubber, PVC paint, and PE. Penetration increases in the order H₂ ³⁵SO₄, Na¹²⁵I, and HTO.