共查询到19条相似文献,搜索用时 156 毫秒
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启明星1#次临界实验装置是“973”项目——加速器驱动洁净核能系统(ADS),02课题为研究次临界反应堆中子学,进行次临界反应堆中子学实验,校核理论计算程序,检验核数据而设计建造的实验平台。2005年,在启明星1#上进行了一系列工作:上半年,进行了启明星1#实验装置的安装调试和实验仪器的准备;7月18日举行了首次装料仪式;之后,用Am-Be中子源驱动次临界装置,测量启明星1#的中子学特性;于10~11月,实现了高压倍加器与次临界反应堆的对接。外推实验是已进行的一系列实验中的一项。先后用Am-Be源、D-T源、D-D源做外推实验,以得到在不同能谱的外… 相似文献
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启明星1号装置是我国研究ADS次临界中子学的一个快热耦合系统。本文用离散坐标法的程序TWODANT对启明星1号装置能谱进行分析计算。计算结果表明,启明星1号装置具有比较硬的中子能谱,可用以进行有关ADS的研究。 相似文献
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启明星1#次临界装置建成后,在第1阶段的实验研究即用Am-Be稳态外中子源驱动启明星1#次临界装置,Am-Be稳态外中子源的平均中子能谱约4MV,初步测量了其中子学特性后,又于2005年10月到11月进行了第2阶段的实验,,即用高压倍加器产生的脉冲外中子源驱动启明星1#次临界装置。高压倍加器产生的脉冲外中子源能谱为14MV,测量其中子学特性,包括:1)验证第1阶段的实验,外推临界质量;2)跳源方法测量启明星1#的不同装载时的次临界度;3)用脉冲外中子源驱动启明星1#次临界装置,测量不同装载下不同空间位置的中子衰减特性等。其中,外推临界质量与第1阶段… 相似文献
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为提高高温熔盐泵散热器的散热效果,对影响散热器散热面积的重要因素——散热孔的直径和数量进行了数值优化,并将数值模拟得到的热载荷加载到结构体上,分析了热载荷下的热变形。结果表明:散热孔直径为12 mm、散热孔数量为6时,散热流体的流动均匀稳定,泵轴和散热器的综合散热效果较好,最终泵轴顶端的平均温度可降到440 K,散热器顶端的平均温度可降到417.5 K,满足散热需求;泵轴热变形量较小,最大值为0.46 mm,散热器的变形量较大,最大值为2.37 mm,加工时必须考虑材料的热膨胀和热变形。 相似文献
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提出了一种新型的超临界水堆概念设计:混合能谱超临界水堆,它包括慢谱区和快谱区两部分.其慢谱区燃料组件采用双排燃料组件,快谱区采用简单的正方形栅元燃料组件.慢谱区与快谱区的燃料组件都采用同向流动方式来简化堆芯设计.慢谱区的冷却剂出口温度远低于整个堆芯的出口温度,这大大降低了慢谱区包壳的温度峰值.此外,由于快谱区冷却剂密度很小,流速很高,故可采用较大的栅元结构,这有效地降低了包壳周向局部传热不均匀性.所以混合堆在充分继承慢谱、快谱堆芯优点的基础上,弥补两者的不足. 相似文献
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In order to get detailed information about weld HAZs toughness of SQV-2A steel and determine the optimum welding and heat treatment parameters, the toughness of simulated CGHAZs (coarse grained heat affected zone) and CGHAZs (intercritically reheated CGHAZ) were systematically investigated. The influence of tempering thermal cycles on weld ICCGHAZs toughness was clarified. The effect of post weld heat treatments (PWHT) on weld CGHAZs toughness was also determined. The results showed that high toughness (absorbed energy >200 J) of weld HAZs could be achieved by selecting the optimum welding and PWHT parameters (cooling time Δt8/5: 6–40 s, PWHT: 893 K, 3.6–7.2 ks). Tempering thermal cycles with peak temperature of above 573 K could remarkably improve the toughness of deteriorated ICCGHAZs and reduce the hardness, when cooling time Δt8/5(2) of the reheating thermal cycle was 6 s, which implies that welding of SQV-2A without PWHT is possible, provided that low heat input welding is adopted and welding procedure is correctly arranged. Metallography and fractography revealed that M–A constituents in weld HAZs played an important role in controlling weld HAZ toughness. 相似文献
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The SCWR core concept SCWR-M is proposed based on a mixed spectrum and consists of a thermal zone and a fast zone. This core design combines the merits of both thermal and fast SCWR cores, and minimizes their shortcomings. In the thermal zone co-current flow mode is applied with an exit temperature slightly over the pseudo-critical point. The downward flow in the thermal fuel assembly will provide an effective cooling of the fuel rods. In the forthcoming fast zone, a sufficiently large negative coolant void reactivity coefficient and high conversion ratio can be achieved by the axial multi-layer arrangement of fuel rods. Due to the high coolant inlet temperature over the pseudo-critical point, the heat transfer deterioration phenomenon will be eliminated in this fast spectrum zone. And the low water density in the fast zone enables a hard neutron spectrum, also with a wide lattice structure, which minimizes the effect of non-uniformity of the circumferential heat transfer and reduces the cladding peak temperature. 相似文献
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The accelerator-driven subcritical system(ADS)with a hard neutron energy spectrum was used to study transmutation of minor actinides(MAs). The aim of the study was to improve the efficiency of MA transmutation while ensuring that variations in the effective multiplication factor(k_(eff)) remained within safe margins during reactor operation. All calculations were completed using code COUPLE3.0. The subcritical reactor was operated at a thermal power level of 800 MW, and a mixture of mononitrides of MAs and plutonium(Pu) was used as fuel.Zirconium nitride(ZrN) was used as an inert matrix in the fuel elements. The initial mass composition in terms of weight percentages in the heavy metal component(IHM)was 30.6% Pu/IHM and 69.4% MA/IHM. To verify the feasibility of this MA loading scheme, variations in k_(eff), the amplification factor of the core, maximum power density and the content of MAs and Pu were calculated over six refueling cycles. Each cycle was of 600 days duration, and therefore, there were 3600 effective full power days.Results demonstrated that the effective transmutation support ratio of MAs was approximately 28, and the ADS was able to efficiently transmute MAs. The changes in other physical parameters were also within their normal ranges.It is concluded that the proposed MA transmutation scheme for an ADS core is reasonable. 相似文献
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The new SCWR conceptual design (SCWR-M) is proposed on the basis of a mixed spectrum core consisting of a thermal spectrum zone and a fast spectrum zone. This new core design is considered to be the hybrid of the existing thermal SCWR and fast SCWR cores. It combines the merits of both thermal and fast SCWR cores, at the same time minimizes their shortcomings. For the thermal zone, the difficulties in the mechanical design and the maximum cladding temperature can be reduced as far as possible by the co-current flow mode; and for the fast zone, a sufficiently large negative coolant void reactivity coefficient and breeding ratio can be achieved by the multi-layer arrangement of fuel rods.The performance, including the burn-up behavior, of the proposed core is investigated with 3-D coupled neutron-physical and thermal-hydraulic calculations. During the coupling procedure, the thermal-hydraulic behavior is analyzed using a sub-channel analysis code and the neutron-physical performance is computed with a 3-D diffusion code. The results obtained so far have shown that the mixed spectrum SCWR concept (SCWR-M) is feasible and promising. 相似文献
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《Annals of Nuclear Energy》1999,26(2):91-110
The critical neutron heating in the reflector control drums is investigated for a fast incore thermionic space craft reactor for power and nuclear propulsion. The reactor is fueled with uranium carbide (UC) and controlled with the help of rotating B4C drums imbedded into the beryllium reflector. While the neutron heating in the drums would not require a cooling mechanism in the power phase, the heat generation during the thrust phase obliges cooling for a nuclear thermal thrust around F = 5000 N by a specific impulse of 670 s−1 at an hydrogen exit temperature around 1900°K. With a beryllium reflector without extra cooling measures, thermal thrust must be kept F < 2500 N to relieve the thermal load in the reflector. On the other hand, a reflector made of BeO may withstand a thermal load for a nuclear thermal thrust of F = 5000 N. The neutronic analysis has been conducted in S16-P3 and S8-P3 approximation with the help of one- and two-dimensional neutron transport codes ANISN and DORT, respectively. A reactor control with boronated reflector drums (drum diameter = 14 cm) at the outer periphery of the radial reflector of 16 cm thickness would make possible reactivity changes of Δkeff = 13.55%—amply sufficient for a fast reactor—without a significant distortion of the fission power profile during all phases of the space mission. Calculations are conducted for a reactor with a core radius of 22 cm and core height of 35 cm leading to power levels around 50 kWel. 相似文献
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基于国内现有的温排放控制标准可执行性不强的现状,以某滨海电站SNP(采用一次直流冷却循环)厂址为例,开展了温排水混合区范围的可接受性论证研究。通过对该电站厂址海域生态调查站位的春、秋季调查结果的聚类分析,得出如下结论:1) SNP一期(1~2号机组)运行工况下,温排水混合区的设定对海域整体生态功能影响较小,其范围可接受;2) SNP一、二期(1~4号机组)同时运行工况下,温排水混合区的设定,春季对海域整体生态功能影响较小,其范围可接受,秋季对海域整体生态功能影响非常显著,如无有效的缓解措施,其影响是不可接受的。 相似文献