Keywords
BNCT
MCNPX
Paraffin
Shield
Abstract
The research aims to measure the radiation dose rate over the radiation shielding which is made of paraffin and aluminium and to determine the best shield material for the safety of radiation workers. The examination used MCNP (Monte Carlo N-Particle) simulator to model the BNCT neutron source and the shield. The shield should reduce radiation to less than the dose limit of 10.42 µSv/h, which is assumed to be the most conservative limit when the duration of workers is 1920 h. The first design resulted in a radiation dose rate which was still greater than the limit. Therefore, optimization was done by adding the lead on the outer part of the shield. After optimization by adding the lead with certain layers, the radiation dose rate decreased, with the largest dose being 57.60 µSv/h. Some locations over the limit could be overcome by other radiation protection aspects such as distance and time. The paraffin blocks were covered by aluminium to keep the shield structure. The lead was used to absorb the gamma ray which resulted from the interaction between the neutrons and aluminium.
References
Aygün B, Budak G. 2012. A new neutron absorber material:oil loaded paraffin wax. Nucl Sci Technol. 2012:33–39.
Benjamin DJ. 2014. The efficacy of surgical treatment of cancer – 20 years later. Med Hypotheses.82(4):412–420. doi:10.1016/j.mehy.2014.01.004.
DiJulio D, Cooper-Jensen C, Perrey H, Fissum K, Rofors E, Scherzinger J, Bentley P. 2017. A polyethylene-B 4 Cbased concrete for enhanced neutron shielding at neutron research facilities. Nucl Instrum Methods PhysRes, Sect A. 859:41–46. doi:10.1016/j.nima.2017.03.064.
Fauziah N, Widiharto A, Sardjono Y. 2015. A conceptual design of neutron collimator in the thermal column of Kartini research reactor for in vitro and in vivo test of boron neutron capture therapy. J Nucl React Technol. 15(2):112–119.
[ICRP] International Commission Radiation Protection. 1999. Report of the Task Group on Reference Man. Technical report. ICRP Publication 23. Oxford:Pergamon Press.
Jasim MH, Abdulameer NT. 2014. Neutron capture cross section measurements of paraffin wax. Int J Appl Innov Eng Manag. 3:112–114.
Mokhtari J, Faghihi F, Khorsandi J, Hadad K. 2017. Conceptual design study of the low power and LEU medical reactor for BNCT using in-tank fission converter to increase epithermal flux. Prog Nucl Energy.95:70–77. doi:10.1016/j.pnucene.2016.11.014.
Padalino S, Oliver H, Nyquist J. 1999. DT neutron yield measurement using neutron activation of aluminium. New York: The State University of New York.
Pokhmurskii V, Zin I, Vynar V, Bily L. 2011. Contradictory effect of chromate inhibitor on corrosive wear of aluminium alloy. Corros Sci. 53(3):904–908. doi:10.1016/j.corsci.2010.11.009.
Sauerwein WA, Moss RL. 2009. Requirements for boron neutron capture therapy (BNCT) at a nuclear research eactor. Technical report. Office for Official Publications of the European Communities. Luxembourg. doi:10.2790/11743.
Shaaban I, Albarhoum M. 2015. Design calculation of an epithermal neutronic beam for BNCT at the Syrian MNSR using the MCNP4c code. Prog Nucl Energy. 78:297–302.doi:10.1016/j.pnucene.2014.10.005.
Warfi R, Harto AW, Sardjono Y, Widarto W. 2016. Optimization of neutron collimator in the thermal column of Kartini research reactor for in vitro and in vivo trials facility of boron neutron capture therapy using MCNP-X Simulator. Indones J Phys Nucl Appl. 1(1):54. doi:10.24246/ijpna.v1i1.54-62.
[WHO] World Health Organization. 2017. The top 10 causes of death. [accessed2017Mar29]. https://www.who-.int/news-room/fact-sheets/detail/the-top-10-caus-es-of-death.
Xoubi N. 2016. Calculation of the power and absolute flux of a source driven subcritical assembly using Monte Carlo MCNP code. Ann Nucl Energy. 97:96–101. doi:10.1016/j. anucene.2016.07.009.
Zeb J, Arshad W, Rashid A, Akhter P. 2010. Gamma shield-ing by aluminum (Al-shielder manual). Technical report.
Pakistan Institute of Nuclear Science and Technology.
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