HTGR控制棒区不连续因子受边界条件的影响

Effect of boundary conditions on the discontinuity factors in the control rod region of an HTGR

为改善高温气冷堆控制棒区物理计算精度,采用不连续因子理论修正扩散方程,使用扩散差分法程序C ITAT ION进行求解。对于1/60和1/30扇区堆芯模型,分析了边界条件和均匀化区对不连续因子计算的影响。结果表明,以离散纵标法程序SN 2D求得的精细网格的输运解为基准,在最大误差2%时,用该方法计算得到的有效增殖因子、反应性价值和活性区的中子注量率分布均与参考解相符。采用不同均匀化模型的不连续因子计算,受边界条件的影响都不大。

The diffusion theory equation corrected by discontinuity factor theory was used in the diffusion difference code CITATION to improve the neutron physics calculations in the control rod region of an high temperature gas cooled reactor （HTGR）. The effects of the boundary conditions and the homogenization region on the discontinuity factors were analyzed using 1/60 sector and 1/30 sector core models. The results show that the effective multiplication factor, keff, the reactivity worth, and the neutron flux distribution agree within 2% of the reference solution using fine mesh in the SN2D transport code with scattered vertical coordinates. The results also show that the discontinuity factor can be calculated by other homogenization models with little influence from the boundary conditions.