Shielding characteristics of ship cabin against early gamma radiation in nuclear explosions
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摘要: 利用蒙特卡罗方法对早期核辐射场景下的舰船舱室屏蔽特性进行研究。使用早期伽马辐射作为辐射源,测定了舰船主体常用的HSLA-80、5456Al及FDCL-3B三种材料的质量衰减系数,并根据舰船的几何结构建立了模拟舱室模型,采用高斯展宽方法对探测器的能谱拟合处理,得到了伽马辐射下舱室内部NaI探测器的吸收能谱,并与文献中的实验结果进行了对比,验证了计算模型和计算结果的可靠性。在此基础上,以伽马防护系数为评价指标,考虑放射性同位素(单能点源)和早期伽马辐射(具有能量分布的面源)两种场景,计算分析了模拟舱室伽马辐射屏蔽的空间分布特性,结果表明:模拟舱室对不同放射性同位素的防护系数是不同的,最多可相差6.74倍(Cd-109与Cs-137);舱室不同位置的防护系数不同。舱室前端的伽马辐射剂量较大,而角落的伽马辐射剂量较小,相差35%;防护系数与伽马辐照的入射角度有关。与正入射相比,模拟舱室对斜45°入射的伽马辐射防护系数更高,可提升43%。Abstract: Monte Carlo method was used to study the shielding characteristics of ship compartments in early nuclear radiation scenarios. Using early gamma radiation as a radiation source, the mass attenuation coefficients of three commonly used materials, HSLA-80, 5456Al, and FDCL-3B, for ship bodies were measured. A simulated cabin model was established based on the geometric structure of the ship, and Gaussian broadening method was used to fit the detector's energy spectrum. The absorption energy spectrum of the NaI detector inside the cabin under gamma radiation was obtained, and compared with experimental results in the literature, thus verified the reliability of the calculation model and results. On this basis, using the gamma protection coefficient as the evaluation index, considering two scenarios of radioactive isotopes (single energy point sources) and early gamma radiation (surface sources with energy distribution), the spatial distribution characteristics of gamma radiation shielding in simulated cabins were calculated and analyzed. The results show that the protection coefficient of the simulated cabins for different radioactive isotopes was different, with a maximum difference of 6.74 times (Cd-109 and Cs-137); The protection coefficient varies in different positions of the cabin. The gamma radiation dose at the front end of the cabin is relatively high, while the gamma radiation dose at the corners is relatively low, with a difference of 35%; The protection coefficient is related to the incident angle of gamma irradiation. Compared with normal incidence, the simulated cabin has a higher gamma radiation protection coefficient for oblique 45° incidence, which can be improved by 43%.
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Key words:
- mass attenuation coefficient /
- ship cabin /
- gamma radiation /
- gamma protection factor
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表 1 材料元素构成
Table 1. Composition of mterial elements
element chemical composition/% 5456Al HSLA80 FDCL-3B 5456Al HSLA80 FDCL-3B Al Fe Na 92.6 98.2 8.6 Si C Ca 0.25 0.22 4.4 Cu Cu Si 0.1 0.5 26 Mg Mn O 5 0.6 60 Zn Ni 0.25 0.4 Mn P 1 0.08 Ti 0.2 Fe 0.4 Cr 0.2 表 2 不同单峰值源的GPF计算
Table 2. GPF calculation for different singlepeak value sources
radioisotope peak value/MeV GPF Cs-137 0.662 1.022 Co-57 0.123 2.457 Cd-109 0.088 6.89 -
[1] 刘晓红, 王伟力, 孟涛, 等. 早期核辐射毁伤效应空间建模及剖切算法[J]. 火力与指挥控制, 2012, 37(9):190-192,197 doi: 10.3969/j.issn.1002-0640.2012.09.051Liu Xiaohong, Wang Weili, Meng Tao, et al. Research on 3D spatial data models for early nuclear radiation damage effects and slitting algorithm[J]. Fire Control & Command Control, 2012, 37(9): 190-192,197 doi: 10.3969/j.issn.1002-0640.2012.09.051 [2] 陈英琦, 陈玲燕, 张哲, 等. 用 γ射线能谱法测量材料的吸收系数和厚度[J]. 同位素, 2004, 17(1):21-26 doi: 10.3969/j.issn.1000-7512.2004.01.006Chen Yingqi, Chen Lingyan, Zhang Zhe, et al. The absorption coefficient of materials and thickness measurement by γ-ray energy spectrum analysis[J]. Journal of Isotopes, 2004, 17(1): 21-26 doi: 10.3969/j.issn.1000-7512.2004.01.006 [3] 周剑良, 吕洋, 程晓龙, 等. 基于MCNP程序和γ射线能谱法对未知材料线吸收系数的测定[J]. 科学技术与工程, 2013, 13(22):6580-6582,6620 doi: 10.3969/j.issn.1671-1815.2013.22.041Zhou Jianliang, Lü Yang, Cheng Xiaolong, et al. Study of the unknown line absorption coefficient of material by MCNP program and γ-ray energy spectrum analysis[J]. Science Technology and Engineering, 2013, 13(22): 6580-6582,6620 doi: 10.3969/j.issn.1671-1815.2013.22.041 [4] Singh K J, Kaur S, Kaundal R S. Comparative study of gamma ray shielding and some properties of PbO–SiO2–Al2O3 and Bi2O3–SiO2–Al2O3 glass systems[J]. Radiation Physics and Chemistry, 2014, 96: 153-157. doi: 10.1016/j.radphyschem.2013.09.015 [5] Abutalib M M, Yahia I S. Novel and facile microwave-assisted synthesis of Mo-doped hydroxyapatite nanorods: characterization, gamma absorption coefficient, and bioactivity[J]. Materials Science and Engineering: C, 2017, 78: 1093-1100. doi: 10.1016/j.msec.2017.04.131 [6] Dickson E D, Hamby D M. Experimental shielding evaluation of the radiation protection provided by the structurally significant components of residential structures[J]. Journal of Radiological Protection, 2014, 34(1): 201-221. doi: 10.1088/0952-4746/34/1/201 [7] Rammah Y S, Mahmoud K A, Mohammed F Q, et al. Gamma ray exposure buildup factor and shielding features for some binary alloys using MCNP-5 simulation code[J]. Nuclear Engineering and Technology, 2021, 53(8): 2661-2668. doi: 10.1016/j.net.2021.02.021 [8] Khattab K, Boush M, Alkassiri H. Dose mapping simulation using the MCNP code for the Syrian gamma irradiation facility and benchmarking[J]. Annals of Nuclear Energy, 2013, 58: 110-112. doi: 10.1016/j.anucene.2012.11.009 [9] Wang M J, Sheu R J, Peir J J, et al. Criticality calculations of the HTR-10 pebble-bed reactor with SCALE6/CSAS6 and MCNP5[J]. Annals of Nuclear Energy, 2014, 64: 1-7. doi: 10.1016/j.anucene.2013.09.031 [10] Hamzah A, Kuntoro I. Desain konseptual perisai radiasi reaktor RRI-50[J]. Jurnal Teknologi Reaktor Nuklir Tri Dasa Mega, 2015, 17(2): 99-110. doi: 10.17146/tdm.2015.17.2.2315 [11] Erwin W J. Verification and validation of Monte Carlo N-Particle 6 for computing gamma protection factors[D]. Wright-Patterson Air Force Base: Air University, 2015. [12] El Ouahdani S, Boukhal H, Erradi L, et al. Monte Carlo analysis of KRITZ-2 critical benchmarks on the reactivity temperature coefficient using ENDF/B-VII. 1 and JENDL-4.0 nuclear data libraries[J]. Annals of Nuclear Energy, 2016, 87: 107-118. doi: 10.1016/j.anucene.2015.07.010 [13] Abrefah R G, Essel P A A, Odoi H C. Estimation of the dose rate of nuclear fuel of Ghana Research Reactor-1 (GHARR-1) using ORIGEN-S and MCNP 6[J]. Progress in Nuclear Energy, 2018, 105: 309-317. doi: 10.1016/j.pnucene.2018.02.002 [14] Hamzah A, Suwoto, Adrial H. Preliminary analysis of dose rates distribution of experimental power reactor 10 MW using MCNP[J]. Journal of Physics:Conference Series, 2019, 1198: 022038. doi: 10.1088/1742-6596/1198/2/022038 [15] Knoll G F. Radiation detection and measurement[M]. 4th ed. Hoboken: John Wiley & Sons, 2010. [16] 方志刚, 刘斌, 李国明, 等. 舰船装备材料体系发展与需求分析[J]. 中国材料进展, 2014, 33(7):385-393Fang Zhigang, Liu Bin, Li Guoming, et al. Requirement and development analysis of warship equipment materials system[J]. Materials China, 2014, 33(7): 385-393 [17] 吴始栋. 美海军开发舰船用高强度耐腐蚀铝合金[J]. 鱼雷技术, 2005, 13(3):49-52Wu Shidong. Introduction to high strength and corrosion resistant aluminum alloy of ships developed by the US navy[J]. Journal of Unmanned Undersea Systems, 2005, 13(3): 49-52 [18] 韩良文, 高业栋, 夏星汉, 等. 基于MCNP的HPGe探测器无源效率刻度[J]. 核安全, 2020, 19(3):76-80Han Liangwen, Gao Yedong, Xia Xinghan, et al. Passive efficiency calibration of HPGe detector based on MCNP[J]. Nuclear Safety, 2020, 19(3): 76-80 [19] Leung J K C. Application of shielding factors for protection against gamma radiations during a nuclear accident[J]. IEEE Transactions on Nuclear Science, 1992, 39(5): 1512-1518. doi: 10.1109/23.173235