共查询到10条相似文献,搜索用时 46 毫秒
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《等离子体科学和技术》2015,17(7):539-544
The error field penetration is numerically studied in the frame of the visco-resistive magnetohydrodynamics(MHD) model.A transition scaling is obtained to link the Rutherford and Waelbroeck regimes in the nonlinear phase of error field penetration process.Furthermore,a transition density scaling of[b_r/B_T]_(crit)~n_e~(1/2) obtained in accord with recent experimental observations in the J-TEXT tokamak. 相似文献
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在中子输运的深穿透屏蔽计算中,采用有效的MCNP减方差技巧可以有效缩减计算时间提高计算效率。以一维聚变反应堆(CFETR)平板模型作为深穿透屏蔽计算实例,分别应用了几何分裂与轮盘赌、源偏倚、强迫碰撞、权窗、指数变换等减方差技巧,对各种减方差技巧应用过程中遇到的如中子平分布问题,全零权窗问题等问题,进行了分析总结,并在此基础上提出了针对深穿透问题的新的解决思路。通过不同方法分析和组合,获得了权窗和指数变换的最佳组合,使计算效率加速了162倍。 相似文献
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设计了一种用于核电厂通风净化系统吸附剂的取样装置,该装置可提供与净化系统内碘吸附剂具有同样运行历史的浸渍活性炭碘吸附剂样品以方便进行定期监督试验。相关验证试验结果表明:6个取样样杯之间的压差非常接近,且流速均在吸附剂流速的±10%之内,因此可以确保6个样杯内的活性炭样品具有相同的与运行气体的接触特性,从而具有同样的代表性;通过6个取样样杯的风速与通过系统主体的风速一致,因而保证了取样样杯里的吸附剂与系统主体的吸附剂具有相同的与空气接触特性;加装取样装置对净化系统的运行没有影响。 相似文献
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反应堆屏蔽计算是粒子输运数值计算的难点问题之一。由于仅有少量处于堆芯外围组件的高能中子能到达屏蔽层外,如果对源粒子采用无偏抽样,大量的计算时间用于模拟无用的源粒子,计算效率很低。偏倚抽样是提升蒙特卡罗模拟计算效率的重要途径,包含源偏倚、输运偏倚和碰撞偏倚等。MCNP程序的权窗发生器可为输运偏倚和碰撞偏倚提供参数,但不包含源偏倚。本文利用正向蒙特卡罗计算权窗发生器产生的重要性函数,生成源偏倚参数以及与之匹配的权窗系数,在屏蔽计算中取得了很好的效果。本文的方法与MCNP的权窗功能完全兼容,使用方便。 相似文献
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Isamu Sato Koji Maeda Mitsuo Suto Masahiko Osaka Toshiyuki Usuki Shin-ichi Koyama 《Journal of Nuclear Science and Technology》2013,50(4):580-587
Penetration behavior of radionuclides such as 137Cs into dried concrete material, dried mortar material and epoxy paint for a few dozen days was observed using a solution containing fission products extracted from irradiated fuels to obtain fundamental information on the radionuclide penetration rate and depth. Hardly any radionuclides could penetrate into the epoxy paint. The radionuclide solution penetrated into concrete and mortar materials to a depth of a few millimeters for a few dozen days. The penetration behavior observed near the surface of concrete and mortar materials was similar to the diffusion of nuclides in media such as water-saturated concrete, bentonite and cement materials. 相似文献
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Nobuyuki Nakashio Takeshi Osugi Hirokatsu Iseda Toshio Touhei Tomoyuki Sudo Joji Ishikawa 《Journal of Nuclear Science and Technology》2016,53(1):139-145
To clarify the operating conditions for the homogenization of metallic low-level radioactive wastes (LLW), melting tests were conducted in the metal melting system of the Advanced Volume Reduction Facilities at the Japan Atomic Energy Agency (JAEA). Simulated metallic LLW with a non-radioactive tracer were melted in the induction furnace of the metal melting system. Regardless of the chemical composition or amounts of the simulated wastes, the tracer distribution in the solidified products was nearly homogeneous when the simulated wastes were completely melted in the range from 1550 °C to 1638 °C. 相似文献