共查询到19条相似文献,搜索用时 156 毫秒
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介绍了利用硼中毒法测量微型临界堆芯硼中毒效应的实验研究结果。为了研究硼酸在该堆芯中的中毒效应,利用硼中毒法采用数字反应性仪和自动电位滴定仪及秒表测量了硼微分价值、堆芯临界硼浓度、堆芯后备反应性等。实验结果表明:实测值与理论计算值相符,结果可信;该实验结果可用于验证理论计算,也可为该堆型的带功率运行提供参考。 相似文献
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采用CFX10.0模拟了反应堆发生非均匀硼稀释事故时的瞬态三维流场,得到堆芯冷却剂的硼浓度分布和温度分布。比较三种不同堆芯温度工况计算结果,发现随着堆芯温度的增加,运动阻力下降,清水越快到达堆芯,清水与硼水的搅混时间减少,搅混效果减弱,堆芯中心处冷却剂的硼浓度偏低。 相似文献
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SHB—5临界装置铀水栅堆芯硼微分价值和总后备反应性的测量 总被引:1,自引:1,他引:0
介绍了SHB-5临界装置铀水栅堆芯硼微分价值的测量,给出了利用非线性牛顿迭代法得到的硼微分价值符合曲线和几种典型硼浓度的硼反应性积分价值;同时给出了利用硼微分价值符合曲线得到的控制棒积分价值、可燃毒物棒总价值和堆芯总后备反应性;这些结果与脉冲中子源法测量结果基本符合。 相似文献
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秦山核电厂堆芯可燃毒物材料为GG-17硼硅酸盐玻璃。它的化学成分、理化性能和美国西屋公司用的Pyyex-7740玻璃相当。因为GG-17玻璃和冷加工的不锈钢包壳都具有好的物理、力学、抗腐蚀和辐照性能,因此从这些实验结果可以预期硼硅酸盐玻璃可燃毒物棒可以成功地用于秦山核电厂。秦山核电厂堆芯可燃毒物从原来的硼不锈钢改成GG-17玻璃后,也将给电厂带来较大的经济效益。 相似文献
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核供热反应堆重力注硼系统分析 总被引:3,自引:3,他引:0
重力注硼系统不仅设备简单、经济,而且具有非能动安全特性。本文采用一组双组份两流体方程式描述系统的物理过程,分析注硼过程中系统参数的变化。分析结果表明,系统工作可靠,能够确保堆芯的安全。 相似文献
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选用硼溶液注入停堆系统作为5MW THR 的紧急备用液体停堆系统,硼溶液在紧急情况下注入反应堆堆芯后的混合特性是反应堆热工、物理和安全设计不可缺少的。本文叙述了硼注入质量传递的可视实验研究,以及硼模拟介质注入下联箱后与冷却剂水在不同的(ρ_(?)ω_(?))/(ρ_D/ω_D)时的混合现像。 相似文献
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对10MW高温气冷实验堆(HTR-10)反射层石墨毒物对平衡态堆芯特性的影响进行了敏感性分析计算,并且研究了反射层毒物浓度为5.2mg/L硼当量的情况下反应性的补偿手段。结果表明:毒物的存在,致使反应性下降,为了补偿这种效应,需要增大燃料中^235U的富集度或者增大堆芯装料体积。本文工作可为HTR-10燃料中^235U的富集度以及其它参数的选取提供参考依据。 相似文献
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重反射层的应用可提高反应堆中子经济性,其结构和中子吸收特性均与压水堆常规围板/反射层差异较大,因此对核设计程序的计算分析能力提出了新的要求。为分析重反射层建模方案对堆芯中子学计算结果的影响,使用先进中子学程序SCAP N和确定论堆芯高保真模拟程序NECP X对压水堆重反射层问题进行了高保真模拟,分析了5种反射层建模方案下计算结果的差异,并将高精度计算结果与商用核设计程序系统进行了对比。数值结果表明,重反射层水洞内冷却剂温度变化对计算结果影响较小;相较精确建模方案,重反射层铁水打混建模方案造成的反应性计算偏差在±30 pcm以内、组件相对功率分布计算偏差在±2%以内。 相似文献
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In this paper, the effect of changes in neutron reflector type on neutronics parameters of Tehran research reactor is analyzed. In this study, at first, calculations for the HEU and LEU fuel configurations of the reactor core in which the light water is used as a neutron reflector in the core is done. Then, by using the reflectors such as graphite, beryllium and heavy water, changes on the neutronic parameters are examined. The results show that by altering the reflector, at HEU core configuration (compared with LEU), more changes appear in parameters such as neutron multiplication factor, average fast and thermal neutron flux, excess reactivity and shut down margin. Moreover, at LEU core configuration, changes are tangible specifically on parameters of cycle length and power peaking factor. In addition, the evaluated fuel temperature coefficient of reactivity is greater at HEU than LEU, while the temperature alteration of fuels represented greater influence on reactivity at LEU configuration. 相似文献
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Masahiro Fukushima Yasunori Kitamura Masaki Andoh Teruhiko Kugo 《Journal of Nuclear Science and Technology》2013,50(10):961-965
A reflector reactivity worth was measured by replacing stainless steel with zirconium at the FCA. The experimental result of the positive reflector reactivity worth demonstrates the effectiveness of the zirconium reflector compared with the SS reflector in the fast reactor core. This paper also focuses on the validation of standard calculation methods used for fast reactors with JENDL-4.0. As a result, it is confirmed that the standard calculation methods for the reflector reactivity worth show agreement within the experimental error. 相似文献
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《Journal of Nuclear Science and Technology》2013,50(12):1201-1211
Experimental and computational studies have been performed on the temperature coefficients of reactivity in light-water moderated and reflected UO2 cores with soluble poisons such as boron and gadolinium. Experiments were carried out using the Tank-type Critical Assembly (TCA) in Japan Atomic Energy Research Institute (JAERI). Temperature coefficients of the cores with soluble poisons were measured by changing the temperature of the moderator and reflector from the room temperature to about 60°C. The dependence of temperature coefficients on the core configuration and the concentration of soluble poison was studied with the water level worth method. Temperature coefficients were calculated with a diffusion code CITATION included in the SRAC code system and a perturbation code CIPER for comparison with the experimental data. It was found that the temperature coefficients are always negative in the experimental cores (the water to fuel volume ratio (Vm/Vf) of 1.83) containing boron as soluble poison. On the other hand, the temperature coefficients become positive in the cores with gadolinium due to the deviation of the gadolinium absorption cross section from the 1/v law and the neutron spectral shift with the increase in temperature. 相似文献
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The Submersion-Subcritical Safe Space (S4) reactor, developed for future space power applications and avoidance of single point failures, is presented. The S4 reactor has a Mo–14% Re solid core, loaded with uranium nitride fuel, cooled by He–30% Xe and sized to provide 550 kWth for 7 years of equivalent full power operation. The beryllium oxide reflector of the S4 reactor is designed to completely disassemble upon impact on water or soil. The potential of using Spectral Shift Absorber (SSA) materials in different forms to ensure that the reactor remains subcritical in the worst-case submersion accident is investigated. Nine potential SSAs are considered in terms of their effect on the thickness of the radial reflector and on the combined mass of the reactor and the radiation shadow shield. The SSA materials are incorporated as a thin (0.1 mm) coating on the outside surface of the reactor core and as core additions in three possible forms: 2.0 mm diameter pins in the interstices of the core block, 0.25 mm thick sleeves around the fuel stacks and/or additions to the uranium nitride fuel. Results show that with a boron carbide coating and 0.25 mm iridium sleeves around the fuel stacks the S4 reactor has a reflector outer diameter of 43.5 cm with a combined reactor and shadow shield mass of 935.1 kg. The S4 reactor with 12.5 at.% gadolinium-155 added to the fuel, 2.0 mm diameter gadolinium-155 sesquioxide interstitial pins, and a 0.1 mm thick gadolinium-155 sesquioxide coating has a slightly smaller reflector outer diameter of 43.0 cm, resulting in a smaller total reactor and shield mass of 901.7 kg. With 8.0 at.% europium-151 added to the fuel, along with europium-151 sesquioxide for the pins and coating, the reflector's outer diameter and the total reactor and shield mass are further reduced to 41.5 cm and 869.2 kg, respectively. 相似文献
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在失水事故长期冷却过程中,必须确定安全注射系统从冷段注射切换到冷热段同时注射的切换时间。这对避免反应堆堆芯硼结晶、堆芯因地坑硼浓度过低而引起重返临界有着十分重要的意义。介绍了大亚湾核电站18个月换料设计失水事故长期冷却分析,应用REFLET程序分析计算了失水事故后堆芯和地坑的硼浓度随时间的变化,给出了不同换料水箱硼浓度下的容许切换时间。当换料水箱硼浓度为2204mg/L时,操作员必须在6小时以前将安注由冷段注射切换到冷、热段同时注射的模式。 相似文献