| Full text | |
| Author(s): |
Cardoso da Silva, Paulo Sergio
[1]
;
de Campos, Marcia Pires
[1]
;
El Hajj, Thammiris Mohamad
[2]
;
Reis, Guilherme de Lima
[1]
Total Authors: 4
|
| Affiliation: | [1] Inst Pesquisas Energet & Nucl IPEN CNEN SP, Av Prof Lineu Prestes 2242, BR-05508000 Sao Paulo, SP - Brazil
[2] Univ Fed Alfenas UNIFAL MG, Rodovia Jose Aurelio Vilela 11999, BR-37715400 Pocos De Caldas, MG - Brazil
Total Affiliations: 2
|
| Document type: | Journal article |
| Source: | Health Physics; v. 121, n. 2, p. 117-123, AUG 2021. |
| Web of Science Citations: | 0 |
| Abstract | |
Radiation workers are normally exposed to doses resulting from their day-to-day activities. Besides that, background radiation, such as radon, can contribute to the exposure rates. The radionuclide Rn-222 is a noble gas belonging to the uranium series, and its indoor concentration in the air depends on the exhalation from surrounding soil and the exhalation from building materials. Radon exhaling from porous building materials containing high uranium concentrations can become a significant exposure factor in areas with limited ventilation. The objective of this study was to evaluate the Rn-222 concentrations in the radiochemistry and radiometric laboratories in the nuclear reactor building of the Nuclear Reactor Center (CERPq) located in the Institute of Nuclear and Energy Research (IPEN), Sao Paulo, Brazil. Measurements were done using a Radon Gas Monitor, model RAD7, equipped with a solid-state alpha detector. A passive method (SSNTD) was also used, consisting of square pieces of C-39 foils (2.5 cm x 2.5 cm) placed within small diffusion chambers. The CR-39 detectors were etched in KOH 30% solution at 80 degrees C for 5.5 h in a constant-temperature bath. After etching, the detectors were washed, dried, and scanned using a microscope to obtain the track density measurements. The activity concentrations measured with both techniques varied from 52 to 103 Bq m(-3) in the studied areas of the CERPq. These values may be compared to the reference level of 100 Bq m(-3) established by the World Health Organization to ensure safety environments. (AU) | |