共查询到19条相似文献,搜索用时 78 毫秒
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文章介绍了国际原子能机构(IAEA)对六氟化铀货包提出火烧试验的背景,综述并评价了世界各国对48型货包耐火烧性能的研究成果,提供了值得参考的研究数据。对比了国外六氟化铀货包火烧试验的实施情况与国内六氟化铀货包法规标准的现状,建议完善国内法规标准和加强六氟化铀48型货包的耐火烧性能研究。 相似文献
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利用MONK-9A和MCNP程序对UX-30型UF6运输货包进行了正常与事故工况下的核临界安全分析与评价。首先选取国际公布的临界基准实验数据,验证并确定了MONK-9A和MCNP程序计算分析类似物料形态时的偏倚和次临界限值。其次采取较为包络的临界安全假设条件,计算分析了UX-30型UF6运输货包正常与事故工况下的中子有效增殖因数,评价了运输过程的安全性。计算结果表明,UX-30型UF6运输货包在最严重事故工况下最大的keff小于确定的次临界限值,处于次临界的安全状态。根据临界安全指数的定义,UX-30货包的临界安全指数CSI可定为0。 相似文献
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金成赫韦应靖王勇黄亚雯冯梅张庆利 《辐射防护》2014,(4):234-239
环境γ监测设备对小剂量率变化的灵敏度是评价其辐射特性的一项重要指标。本文介绍了一种自行研制的烟羽辐射模拟装置,该装置由137Cs放射源及其传动系统、铅屏蔽体、不同厚度的铅衰减环、控制单元等组成。利用蒙特卡罗模拟和G(E)函数法对距离装置放射源3 m、离地面1 m高度处的空气比释动能率进行了计算,由上述两种方法得到的结果相对偏差在5%以内。结果表明,此烟羽辐射模拟装置在装载MBq量级的137Cs源时,预计可提供10 nGy/h^50 nGy/h的辐射场,可用于环境γ监测设备对小剂量率变化的灵敏度测试。 相似文献
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出于辐射防护目的,通常假定辐射诱发癌症的总危险是随着剂量呈线性无阈(Linear Non Threshold,LNT)增加。然而,现有流行病调查结果不能完全支持验证LNT,同时低剂量辐射生物效应研究发现了新的不利于LNT模型的成果,且现有的资料并不排除有阈值存在,剂量响应关系的变化依赖于所论及癌症的类型、剂量、剂量率、辐射的传能线密度(Linear Energy Transfer,LET)、受照个体的年龄、性别和生理状态以及其他因素。尽管不排除其他剂量响应关系的存在,低水平辐射致癌效应的分析中没有其他模型比LNT模型更能被业界广泛接受。在新理论、新模型产生前,遵循现有理论和LNT模型评估辐射危害仍然是目前最科学的态度,同时也是最有利于辐射防护的方法论。 相似文献
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高飞肖雪夫倪宁宋明哲侯金兵王红玉 《辐射防护》2014,(3):134-137
固定式环境γ辐射剂量率监测仪表是承担环境连续监测任务的主要设备,这类仪表通常不便于拆卸和安装,而且送检周期较长(一周左右),影响了连续监测点数据的连续性。为了固定式仪表的按期校准,结合蒙卡方法研制了便携式137Cs照射装置,利用PTW剂量计对辐射场进行标定,最后利用便携式照射装置对固定式环境γ辐射剂量率监测仪表进行现场校准实验。 相似文献
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开展环境空气中(14)^C的监测是核电厂辐射环境监督性监测的重要内容。本文给出了宁德核电厂周围环境空气中(14)^C的取样与监测方法,分析了2013—2021年间监测结果变化及趋势,对比分析了运行前辐射本底调查结果、对照点监测结果及国内外其他核电厂的监测结果,并与宁德核电厂气态流出物排放量进行了相关性研究。分析表明,核电厂周围各监测点位空气中C的比活度均值范围为0.229~0.230 Bq/g(碳),其中距离厂址最近的牛郎岗监测点的结果可能受到核电厂排放的影响。分析了(14)^C比活度的年周期变化规律,结果表明,除牛郎岗监测点外,(14)^C的比活度一般在7—9月相对较高。 相似文献
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《Packaging, Transport, Storage and Security of Radioactive Material》2013,24(4):172-178
AbstractThree Latin American countries which operate research reactors, Argentina, Brazil and Chile, have joined efforts to improve the capability in the management of spent fuel elements from the reactors operated in the region. As a step in this direction, a packaging for the transport of irradiated fuel from research reactors was designed by a tri-national team and a half scale model for materials test reactor fuel was constructed in Argentina and tested in Brazil. Three test campaigns have been carried out so far, covering both normal conditions of transportation and hypothetical accident conditions.In this paper both the numerical modelling and mechanical tests to select adequate shock absorbers materials are presented. Results of these tasks are used to improve the cask design. 相似文献
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Identifying the geometric information of an object by analyzing the detected radiation fields is an important problem for national and global security.In the present work,an inverse radiation transport model,based on the enhanced differential evolution algorithm with global and local neighborhoods (IRT-DEGL),is developed to estimate the unknown layer thickness of the source/shield system with the gamma-ray spectrum.The framework is briefly introduced with the emphasis on handling the enhanced differential evolution algorithm.Using the simulated gamma-ray spectra,the numerical precision of the IRT-DEGL model is evaluated for one-dimensional source systems.Using the detected gamma-ray spectra,the inverse investigations for the unknown thicknesses of multiple shielding layers are performed.By comparing with the traditional gamma-ray absorption method,it is shown that the IRT-EDGL model can provide a much more accurate result and has great potential to be applied for the complicated systems. 相似文献
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Tomás Mora Adrian Aguilar Luis Mena Maite Mancisidor Jorge Aguilar 《Journal of Nuclear Science and Technology》2018,55(5):548-558
The details concerning the generation and accumulation of radionuclides produced by spallation reactions within the neutron generation target to be installed at the European Spallation Source are described. The resulting radiation damage for the target tungsten blocks constituents as well as the target encasing is evaluated and explicit results are given for the effects of knock-on atoms as well as those resulting from the accumulation of light and volatile hydrogen and helium isotopes resulting from spallation reactions. Their effects on the mechanical properties are discussed on the light of available experimental data and, on this basis, an estimation of the target lifetime is given. 相似文献
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