Sains Malaysiana 38(3): 407-411(2009)
Hazard Radiologi Radionuklid Tabii Dalam Simen
Portland Semenanjung Malaysia
(Radiological hazard of
natural radionuclide in portland
cement of Peninsular Malaysia)
Aznan Fazli Ismail*, Muhamad Samudi Yasir, Amran Ab. Majid,
Redzuwan Yahaya, Ismail Bahari
Program Sains Nuklear, Fakulti Sains Dan Teknologi
Universiti Kebangsaan Malaysia, 43600 Bangi, Selangor D.E., Malaysia
Diserahkan: 16 Julai 2008 / Diterima: 23 Ogos 2008
ABSTRAK
Selain daripada
batu-batu kecil, batu kerikil dan pasir, simen merupakan salah satu bahan
penting untuk membina bangunan. Simen diperbuat daripada campuran batuan dan
tanah dan diketahui secara semulajadinya mengandungi radionuklid tabii. Kajian
ini bertujuan untuk menentukan aras keradioaktifan tabii serta menilai hazard
sinaran yang berpunca daripada radionulid tabii di dalam simen Portland di
Malaysia. Sampel simen Portland diperolehi dari kilang pengeluar simen atau
dibeli di pasaran tempatan. Kepekatan radionuklid tabii bagi 226Ra
(siri 238U), 232Th dan 40K ditentukan dengan
menggunakan spektrometri sinar gama. Hasil kajian mendapati julat kepekatan
aktiviti bagi 226Ra (siri 238U), 232Th dan 40K
masing-masing adalah 7.76 – 82.91 Bq kg-1, 9.79 – 49.37 Bq kg-1 dan 81.89 – 377.10 Bq kg-1. Purata nilai kesetaraan radium
berada dalam julat 35.36 ± 0.60 hingga 135.94 ± 15.27 Bq kg-1 manakala julat purata bagi dos setara
tahunan dan indeks hazard dalaman adalah masing-masing ialah 80 ± 2 hingga
300 ± 30 µSv tahun-1 dan 0.12
± 0.00 hingga 0.56 ± 0.07
Kata kunci: Hazard
sinaran; keradioaktifan tabii; simen Portland
ABSTRACT
Besides bricks,
granites and sands cement is one of the main components of building materials
Cement is made from a combination of rocks and soils which is known to contain
natural radioactivity. The objectives of this study were to determine the level
of natural radioactivity and associated radiological hazard caused by natural
radioactivity in Malaysia’s Portland cements. Portland cements samples were
obtained from the manufacturers or bought directly from local hardware stores.
Natural radionuclide concentrations of 226Ra (238U
series), 232Th and 40K were determined using gamma-ray spectrometry. Activity concentrations of 226Ra (238U
series), 232Th and 40K were found in the range of 7.76 –
82.91 Bq kg-1, 9.79 – 49.37 Bq kg-1 dan 81.89 – 377.10 Bq
kg-1 respectively. Radium equivalent were found in the range of 35.36 ± 0.60 to 135.94 ± 15.27 Bq kg-1 while the average annual equivalent dose and internal
hazard index were found in the range of 80 ± 2 to 300 ± 30 µSv year-1 and 0.12 ± 0.00 to 0.56 ±
0.07 respectively.
Keywords : Natural radioactivity; Portland cement; radiation hazard
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*Pengarang untuk surat-menyurat; email: aznan_sn@yahoo.com
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