Analysis of external radiation exposure from building materials using resrad-build (case study: perumnas bumi guwosari)

One of the natural radiation that is not realized by humans comes from radionuclides in building materials. So, it becomes necessary to study the natural radioactivity in various building materials to calculate the annual effective dose of the public in Perumnas Bumi Guwosari room model. In this paper, activity concentration of ²²⁶Ra, ²³²Th and ⁴⁰K in 5 cement, 5 sand, 5 red brick, and 5 ceramic samples were bought directly from the local hardware store in Yogyakarta were determined by gamma-ray spectrometry with HPGe detector. The activity concentration of ²²⁶Ra, ²³²Th and ⁴⁰K ranged from 23.87 ± 20.88 to 49.31 ± 31.04 Bq.kg⁻¹, 11.56 ± 12.41 to 36.62 ± 14.34 Bq.kg⁻¹ and 0.1443 ± 11.2029 to 58.82 ± 15.01 Bq.kg⁻¹, respectively in various samples. The radium equivalent activity ranged from 17.7338 to 136.8901 Bq.kg⁻¹ are lower than the limit of 370 Bq.kg⁻¹ set by UNSCEAR. The highest value of external and internal hazard indices was found in ceramic samples 0.3705 and 0.5317 are below the UNSCEAR recommendation (H_ext ⩽ 1 and H_in ⩽ 1). The results of calculating the annual effective dose using RESRAD-BUILD ranged 0.654-0.661 mSv.y⁻¹ is lower than the annual recommended limit of 1 mSv.y⁻¹. The parameters that most influence the increase in external radiation dose rate from building materials are the composition, density, and thickness of the floor and wall.