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对包头市城区陆地γ辐射空气吸收剂量率和空气中氡、气土及其子体浓度进行了测量。其中γ辐射空气吸收剂量率瞬时测量平均值为62.5 nGy/h,累积测量平均值为100.7 nGy/h,累积剂量扣除宇宙射线响应值后与瞬时剂量结果一致,与包头市2006年航测结果值(60 nGy/h)相当。气溶胶中氡子体α潜能值12.88 nJ/m3,气土子体α潜能值9.55 nJ/m3,两种子体的α潜能值均在标准限值范围内。通过对照射剂量估算,城区外照射年有效剂量为0.58 mSv,内照射年有效剂量为1.29 mSv,数值略高于全国和世界平均水平,在同水平范围内。包头市城区放射性环境有效剂量未超过规定限值,不会对公众健康造成不良影响。 相似文献
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《核电子学与探测技术》2017,(5)
采用HPGe谱仪测量γ射线能谱,通过一系列的方法实现对剂量率的精确测量。选择多个标准点源对一台HPGeγ谱仪进行能量与效率刻度,并求解得到G函数的具体形式,并在~(137)Csγ标准剂量辐射场中进行刻度与测量。实验结果表明:采用该方法在实际环境中的测量结果与剂量率仪的测试结果的最大误差为±14%。利用环境能谱测量得到环境辐射剂量是一种可行有效的方法。 相似文献
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在台湾的台北和花莲同时对10个测点的建筑物内和建筑物外进行了~(222)Rn(氡)及其子体的浓度和环境γ剂量率测量。台湾夏季氡的室内浓度估计约为20Bq·m~(-3),环境γ剂量率约为90nSv·h~(-1);室外相应地约为10Bq·m~(-3)和约70nSv·h~(-1)。计算出的平衡因子室内为0.2~0.3;室外为0.3~0.4。室内氡浓度与γ剂量率呈弱正相关。台湾可能在冬季因住宅通风率非常差而导致室内氡浓度增高。为了今后评估年有效剂量,需要在冬季1~2月份进行补充测量。 相似文献
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全国环保系统于2002年在四川进行了γ辐射剂量率测量比对.比对结果表明.以高压电离室的测量结果平均值作为参考值.国产的BH型仪器测量数量大多偏低.国产JW型仪器测量数据大多偏高.手枪型小闪烁体剂量率仪测量结果的相对标准差较大。通过这次比对.基本摸清了全国γ剂量率测量仪的性能状况.为今后开展测量比对积累了经验。 相似文献
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论文介绍了在西藏地区海拔1 500~4 500 m高度范围内,利用BR1000型热释光剂量计测量环境地表累积剂量的相关情况。考虑到不同海拔高度宇宙射线强度相差较大,对不同点位测量数据进行了宇宙射线响应修正,并对测量不确定度进行了评定。结果表明:西藏地区环境累积剂量率水平远高于内陆低海拔地区,其中3 000 m以上测点主要为宇宙射线光子及电离成分贡献,TLD布放引入的不确定度最大,布放地点、布放高度、周围环境遮蔽是影响结果误差的决定性因素。 相似文献
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随着核与辐射技术在医学检查、诊断和治疗领域运用的增加,世界范围受照人群不断增多,医源性辐射已成为人类最主要的人工辐射来源之一。医疗机构和个人在选择利用放射手段获取诊断和治疗利益的同时,需要注意和防护伴随的辐射损伤效应。本文介绍了医源性辐射及其危害、机体组织的辐射损伤特性和类型、辐射生物效应分子及效应调节研究的进展,简要概述目前临床已经使用或最具应用潜力的辐射防护策略。 相似文献
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《Journal of Nuclear Science and Technology》2013,50(4):284-291
The selective removal and fixation of Cs and Sr have been studied in zeolite A and chabazite. Cesium ion was preferentially distributed into chabazite with a high distribution coefficient (K Cs>103 cm3·g?1) in the presence of NaCl (10?1 mol·dm?3). The K Sr values for zeolite A attained about 103 cm3·g?1 in the pH range of 8~10, and they gradually decreased with an decrease in pH. The initial rate of Cs adsorption was fairly fast in chabazite, and the adsorption ratio reached almost 100% within a few hours. The adsorption ratio of Sr in binderless A zeolite reached almost 100% after 15 h. The adsorption of Cs and Sr on these zeolites was followed by Langmuir-type isotherm. Cesium forms of these zeolites recrystallized to pollucite (CsAlSi2O6) above 900°C for zeolite A and above 1,200°C for chabazite. As for Sr forms, these zeolites changed to SrAl2Si2O6 above 900°C. These recrystallized phases were suitable hosts for the immobilization of Cs and Sr in the nuclear waste solutions. 相似文献
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Hui-Wen Huang Author Vitae Chunkuan Shih Ming-Huei Chen 《Nuclear Engineering and Design》2009,239(6):1136-1147
This work developed an advanced boiling water reactor (ABWR) feedwater pump and controller model, which was incorporated into Personal Computer Transient Analyzer (PCTran)-ABWR, a nuclear power plant simulation code. The feedwater pump model includes three turbine-driven feedwater pumps and one motor-driven feedwater pump. The feedwater controller includes a one-element/three-element water level controller and a specific feedwater speed controller for each feedwater pump. The performance tests, including step change of dome pressure, feedwater pumps transfer, inadvertent closure of all turbine control valves, and one feedwater pump trip at 100% power, demonstrate the feasibility of dynamic response of stand-alone model and incorporated model. Furthermore, a diversity and defense-in-depth analysis is performed to demonstrate the feasibility for motor-driven feedwater pump as an emergency core cooling system (ECCS) automatic diverse back-up. In Lungmen nuclear power plant (NPP), a diverse manual initiation means for the high pressure core flooder (HPCF) loop C is designed as the back-up of digitalized engineered safety features actuation system (ESFAS). If the motor-driven feedwater pump (MDFWP) can be an automatic digital diverse back-up for ESFAS, Lungmen NPP would be more robust to defend against software common-cause failure (CCF). 相似文献
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清洁解控和退役若干动向与新发展 总被引:2,自引:0,他引:2
对国际辐射防护协会第 1 0届大会 ( IRPA-1 0 )涉及的清洁解控和退役问题作了论述 ,包括排除、豁免、清洁解控和废物最少化 ;退役工程技术的发展 ,包括去污技术、切割解体技术、探测技术 ;介绍了一个研究堆退役例子和加速器退役 ;最后 ,还论及了退役中受关注的一些问题 ,如 :石墨废物、混凝土废物、重水堆退役的氚防护、退役时间和退役废物量等。 相似文献
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面对公众对核与辐射风险极度敏感的现象,本文阐述了对风险的认知及影响认知程度的因素,介绍了风险沟通的发展阶段和四种类型,并给出了若干有效的风险沟通策略建议。 相似文献
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Yuji Ohishi Mitsuyuki Sugizaki Yifan Sun Hiroaki Muta Ken Kurosaki 《Journal of Nuclear Science and Technology》2019,56(9-10):859-865
ABSTRACTFuel debris in the Fukushima Daiichi nuclear power plant is thought to contain borides that are generated from B4C control material. In order to successfully devise methods to effectively remove the debris material, characterization of the properties of the fuel debris is essential. This paper presents some of the thermophysical and mechanical properties of two types of borides, FeB and CrB, and compares them with those of Fe2B and ZrB2. These are the representative borides that might have been generated in the Fukushima Daiichi (1F) nuclear power plant accident. We observed that the thermal conductivity values of both CrB and FeB are much lower than that of ZrB2, and are similar to that of Fe2B. Moreover, the Vickers hardness and fracture toughness of FeB and CrB are almost identical to each other, and similar to those of ZrB2 and Fe2B. 相似文献
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B. N. Laskorin V. S. Ul'yanov R. A. Sviridova A. M. Arzhatkin A. I. Yuzhin 《Atomic Energy》1961,7(2):620-625
Chromatographic methods of separating elements with very similar properties have now been developed. However, a number of these methods are difficult to use industrially as their throughput is low. The efficiency of chromatographic separation methods could be increased considerably by using appropriate complex formers, which decrease the effective concentration of the ions being separated, and,in the first approximation, this is equivalent to a decrease in the amount of elements being separated. The difference in the formation constants of the complex compounds increases the separation coefficient. By investigating chromatographic separation with the use of various complex formers, we found the optimal conditions for separating barium and radium, zirconium and hafnium, and aluminum and gallium. The throughput of these methods, with respect to the macroelement was 15–60 kg/hr per m2 of column cross section. 相似文献
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核电站反应堆测温热电偶回收装置是堆芯热电偶检修、更换、回收的专用设备。本文结合300MW反应堆型,介绍了一种结构简单、操作方便、使用安全可靠的热电偶拔出回收技术及回收处理装置。 相似文献