共查询到19条相似文献,搜索用时 234 毫秒
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本文建立了燃料操作区域气载放射性浓度计算模型,对典型核素气载放射性浓度的变化趋势进行了分析。利用该模型研究了核素类型、通风流量等因素对燃料操作区域气载放射性浓度的影响,最后分析了燃料操作区域气载放射性的主要来源。结果表明,不同核素达到气载放射性浓度最大值的时刻不同,应取各核素燃料操作期间气载放射性浓度最大值作为设计值;燃料操作区域排风量与其净空间体积比值λ_h与气载放射性浓度成反比,反应堆冷却剂中放射性活度是气载放射性的主要来源,可以通过调节排风量、降低冷却剂放射性活度、降低蒸发量将气载放射性控制在一定水平。 相似文献
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根据有关法规标准和核电厂气载排出流放射性监测现场运行经验,对核电厂气载排出流放射性监测系统进行了优化设计。设计中,给出了核电厂烟囱气载排出流取样代表性验证试验的方法和流程,设计了烟囱气载排出流的全量程放射性监测系统,采用比值控制方案控制气载排出流的取样流量,提出了基于粒子群优化改进算法的控制器参数智能优化方法,构建了基于现场总线和冗余通讯网关的放射性监测系统总体网络结构。 相似文献
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高温气冷堆乏燃料元件的放射性裂变产物绝大部分滞留在燃料元件中。10MW高温气冷实验堆在设计寿命内将卸出约9万个乏燃料元件,其放射性裂变产物的活度高达1.9×1017Bq,因此正确实施乏燃料元件的贮存,减少放射性裂变产物向环境中释放和进行有效的屏蔽是极其重要的。本文根据乏燃料元件中放射性裂变产物的计算结果和德国高温气冷堆乏燃料元件贮存的经验.对我国10MW高温气冷堆乏燃料元件贮存中放射性裂变产物进行了安全分析。 相似文献
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【法国《能源快报》1996年6月17日第6596期报道】 乏燃料从核反应堆中卸出暂时贮存于水池之后,可以在核电站场址干式贮存设施中安全储存,而只需要简单的监测。法马通公司将给贮存能力已饱和的亚美尼亚梅察莫尔核电厂提供这种贮存模式。当水池中乏燃料的放射性衰变得足以使其余热可通过自然对流的方式容易地排放时,乏燃料则可以干式贮存于惰性气体中。这是乏燃料已在水池内贮存3—5年后的情况。 相似文献
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以先进压水堆核电厂为对象,开展了正常运行工况安全壳内气载放射性产生方式研究,并构建了分析模型,包括冷却剂泄漏及40Ar中子活化。在此基础上,定量的论证了安全壳空气过滤系统对放射性净化作用,结果表明:无排风净化情况下安全壳大气内放射性水平较高,可达DAC(导出空气浓度)限值15.5倍,应实行较严格的措施限制人员进入;通过敏感性分析,识别出85Kr及133Xe为主导核素,由于这些核素半衰期较长,仅依靠衰变较难去除,采用每周定期20 h净化方案可解决该问题。同时,进一步研究了降功率并发碘尖峰机理模型,论证了停堆工况通风策略的有效性,结果表明:实施大风量净化可在进入冷停堆状态时将安全壳内气载放射性降到DAC限值,为人员在安全壳内进行长期操作提供了条件。 相似文献
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【美国《核电站》2004年1~2月刊】韩国水电核电有限公司(KNHP)核环境技术研究所(NETEC)负责管理来自韩国核电厂和放射性同位素用户的放射性废物,以及为核电厂建立高效的乏燃料贮存系统。在KHNP/NETEC进行的先进放射性废物管理技术研发活动中,最复杂的当数为处理各类中低放废物而开发的玻璃固化技术。最近的测试表明,开发出的这项技术能够成功地用于放射性废物的商业化处理。在将乏燃料运往预期于2016年投入使用的中间贮存设施之前,先对乏燃料进行厂区贮存。由于目前必需扩大乏燃料厂区贮存能力,因此正在进行将乏燃料从现有贮存架搬… 相似文献
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In order to protect the workers in the spent fuel storage compartment from internal radiation, the airborne radioactive concentration in the spent fuel storage compartment needs to be controlled. Exhaustion of the airborne radiation is mainly realized through the ventilation system. According to the characteristics of the spent fuel storage tank, four ventilation methods are designed in this paper. Airpak software is used to simulate the four ventilation methods of the spent fuel storage tank. By comparing and analyzing the polluted steam concentration field, flow field and polluted steam trajectory, the effects of four ventilation methods on the airborne radioactive exclusion are studied. The results show that the layered air supply method Ⅱ has a better effect on the airborne radioactive emissions, and under this ventilation mode, the airborne radioactive concentration on the personnel working platform is lower than that in other three ventilation modes. 相似文献
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《Annals of Nuclear Energy》2005,32(17):1854-1866
The PBMR’s spent fuel and partially burnt fuel are stored in the sphere storage system (SSS), which acts as the interim fuel storage facility of the plant. It is unique in the world since the fuel is stored in bulk containers (called storage tanks), each capable of holding more than 500,000 spheres for a period of about 80 years. The SSS has the ability to transfer the contents of one tank to another tank, and to return partially burnt fuel back to the reactor core for re-fuelling.The storage tanks are individually sealed carbon steel pressure vessels. They form the final barrier of any fission products that have diffused from the fuel spheres. Sub-criticality is achieved through the geometric cross-section of the tank, and by taking credit for fuel burn-up. Protection from the corrosive environment where the PBMR Demonstration plant will be built is achieved by actively cooling the tank with clean dry air. In the event of an active cooling failure, louvres open automatically and cooling is done passively via natural convection making use of the chimney-effect. Sufficient radiation protection is provided around each tank to facilitate maintenance and inspection operations where needed.The design of the SSS is nearing the end of its basic design phase, and for some components, detail design work has already commenced. The design complies with all spent fuel storage requirements and is seen as a cost-effective solution for the interim storage of PBMR spent fuel. 相似文献
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A fundamental criticism regarding the potential for microbial influenced corrosion in spent nuclear fuel cladding or storage containers concerns whether the required microorganisms can, in fact, survive radiation fields inherent in these materials. This study was performed to unequivocally answer this critique by addressing the potential for biofilm formation, the precursor to microbial-influenced corrosion, in radiation fields representative of spent nuclear fuel storage environments. This study involved the formation of a microbial biofilm on irradiated spent nuclear fuel cladding within a hot cell environment. This was accomplished by introducing 22 species of bacteria, in nutrient-rich media, to test vessels containing irradiated cladding sections and that was then surrounded by radioactive source material. The overall dose rate exceeded 2 Gy/h gamma/beta radiation with the total dose received by some of the bacteria reaching 5 × 103 Gy. This study provides evidence for the formation of biofilms on spent-fuel materials, and the implication of microbial influenced corrosion in the storage and permanent deposition of spent nuclear fuel in repository environments. 相似文献
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针对乏燃料水池失水、乏燃料裸露的事故情景,通过实验研究了燃料厂房内空气自然循环及氢气分布的基本规律,得到了空间气体温度场及浓度分布实验数据。结果表明,由于空气自然循环的热量输运作用,各区域升温速率随温度的升高而降低;与外界自然对流通风的简单方式可显著减缓温度上升,实验24 h后加热元件温度低于490 ℃;喷淋则可迅速降低所覆盖区域温度,空间气体平均温度在喷淋后5 min内下降了100 ℃。氢气在空气环境中将形成浓度分层,喷淋搅混可在2 min内破坏该分层;对于氢气/蒸汽混合气体,随着蒸汽凝结及外界空气涌入逐渐具有可燃性,喷淋对此无积极作用。基于上述研究结果,提出了能动和非能动的事故缓解措施建议。 相似文献
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New, unconventional methods developed at the Russian Science Center Kurchatov Institute for evaluating the state of spent
VVR fuel assemblies from submarines are described. They were used in combination with other methods during inspections of
spent fuel assemblies held in TK-6 and -11 containers at the point of storage of spent nuclear fuel and radioactive wastes
in the town of Gremikha in Murmansk Oblast. 相似文献
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CAP1400是中国自主研发的新型反应堆,其乏燃料贮存格架自由地放置在乏燃料水池内,水可在格架内部通道中流通,同时水也存在于格架与格架、格架与池壁之间的间隙中。在地震情况下,格架与流体之间的流固耦合特性非线性度非常高,很难用软件准确地模拟计算。为准确地探究CAP1400乏燃料贮存格架的流固耦合特性,建立了乏燃料贮存格架和水箱缩比试验模型,开展了振动台试验。在扫频试验中,测量了格架支脚与水箱底板间的摩擦系数;同时研究了正弦波、地震波工况下,格架与格架间的间隙对格架滑移现象、流体压力的影响。通过分析试验结果,得到了格架支脚与水池间的摩擦系数;且格架间隙越大,流体压力越小,但格架间隙对滑移现象影响不明显。本试验的结果可为CAP1400乏燃料贮存格架的流固耦合参数选取提供依据。 相似文献