UNIVERSITY OF BUCHAREST
FACULTY OF PHYSICS

Guest
2024-11-23 18:12
 HOME     CONFERENCES     SEARCH            LOGIN     NEW USER     IMAGES   


Conference: Bucharest University Faculty of Physics 2017 Meeting


Section: Atomic and Molecular Physics. Astrophysics. Applications


Title:
Environmental dose assessment for the radionuclides embedded in building materials used in residential buildings


Authors:
Alexandru MICLĂUȘ(1), Ionel LAZANU(2) and Liviu TUGULAN(1)


Affiliation:
1) Horia Hulubei National Institute for Physics and Nuclear Engineering, IFIN-HH

2)University of Bucharest, Faculty of Physics


E-mail
micly90@yahoo.com


Keywords:
natural radionuclide, gamma spectrometry, hazard indexes, dose estimation


Abstract:
Our environment is constantly emitting radiation from natural radionuclides embedded in earth, soils, living materials and cosmic sources. As we basically live with radiation and this radiation is mainly due to natural occurring radioisotopes, a correct assessment for the radionuclides we enclose in our walls and buildings may raise specific concerns. This paper we performed a dose and radiation risk assessment of specific major radionuclides present in common building materials. In order to achieve this, two type of residential buildings were analyzed – one flat on second floor for a building so that the soil radon emissions can be ignored and a house build on the ground currently under construction. Both places are within close range to Bucharest, the flat is from Popesti-Leordeni and the house is located in Magurele, Ilfov. In order to provide a complete and accurate composition assessment for the selected building materials a Xenemetrix ED-XRF model EX-6600 SDD system was used. It is equipped with a X EG 60 radiation generator with Pmax=300 W, HVmax=60 kV and Imax=4.9 mA. The detection system is and SDD (Silicon Drift Detector) with and active area of 25 mm2. Radiometric measurements were performed using a CANBERRA REGe based system with ISOXCALL characterization. The multichannel analyzer was DSA 1000. Detector efficiency is 40% and its resolution is 1.96 keV for 1332 keV (60Co) and 0.89 keV at 122 keV (57Co). Background suppression was done with a Lead shield model CNBERRA 747. The detector window is 0.6mm thick and is made of Carbon Epoxy. The radionuclide concentrations from the building materials were evaluated using High Performance GeHP spectrometry.


References:

Method accuracy for natural radioisotope series within the analyzed building materials was performed by the means of using reference, certified samples provided by the International Atomic Energy Agency: IAEARGTh-1 (Thorium Ore), IAEA-384 (Fangataufa Sediment) and IAEA-385 (Irish Sea Sediment).

CNCAN, 2000. National Commission for the Control of Nuclear Activities, Fundamental Norms on Radiological Safety NSR-01E, http://www.cncan.ro/assets/NSR/nfsr-01-engleza.pdf



Acknowledgement:
The global values were obtained by taking into account the proportion of materials used (based on architectural and structural projects) we can estimate the annual equivalent dose for the two residential places. The lower value was obtained for the Flat where annual equivalent dose is (0.34 ± 0.04) mSv/year –dose rate is (69.4 ± 6.9) nGy/h. For the second case, the house has a dose rate of (74.2 ± 7.9) nGy/h leading to an annual equivalent dose of (0.36 ± 0.04) mSv/year. The dose equivalent effective annually for these two houses is low than limit of 1 mSv/y (CNCAN, 2000), required in Romania, for population.