TY - JOUR JF - Int-J-Radiat-Res JO - Int J Radiat Res VL - 5 IS - 3 PY - 2007 Y1 - 2007/12/01 TI - Production of an economic high-density concrete for shielding megavoltage radiotherapy rooms and nuclear reactors TT - N2 - Background: In megavoltage radiotherapy rooms, ordinary concrete is usually used due to its low construction costs, although higher density concrete are sometimes used, as well. The use of high-density concrete decreases the required thickness of the concrete barrier hence, its disadvantage is its high cost. In a nuclear reactor, neutron radiation is the most difficult to shield. A method for production of economic high-density concrete with appropriate engineering properties would be very useful. Materials and Methods: Galena (PbS) mineral was used to produce of a high-density concrete. Galena can be found in many parts of Iran. Two types of concrete mixes were produced. The water-to-concrete (w/c) ratios of the reference and galena concrete mixes were 0.53 and 0.25, respectively. To measure the gamma radiation attenuation of Galena concrete samples, they were exposed to a narrow beam of gamma rays emitted from a cobalt-60 therapy unit. Results: The Galena mineral used in this study had a density of 7400 kg/m3. The concrete samples had a density of 4800 kg/m3. The measured half value layer thickness of the Galena concrete samples for cobalt- 60 gamma rays was much less than that of ordinary concrete (2.6 cm compared to 6.0 cm). Furthermore, the galena concrete samples had significantly higher compressive strength (500 kg/cm2 compared to 300 kg/cm2). Conclusion: The Galena concrete samples made in our laboratories had showed good shielding/engineering properties in comparison with all samples made by using high-density materials other than depleted uranium. Based on the preliminary results, Galena concrete is maybe a suitable option where high-density concrete is required in megavoltage radiotherapy rooms as well as nuclear reactors. SP - 143 EP - 146 AU - Mortazavi, S.M.J. AU - Mosleh-Shirazi, M.A. AU - Maheri, M.R. AU - Yousefnia, H. AU - Zolghadri, S. AU - Haji-pour, A. AD - KW - High-density concrete KW - galena KW - shielding KW - megavoltage radiotherapy. UR - http://ijrr.com/article-1-328-en.html ER -