重水零功率堆物理计算的第一步就是要保证群参数的正确和可靠。对于重水天然铀堆,热群参数尤其重要。为了确定重水零功率堆物理计算中比较好的群参数计算方法,分别用三套不同的方法计算了重水天然铀棒栅零功率堆的两群扩散参数,再用两群临界 The first step in the physical calculation of heavy water zero-power reactor is to ensure that the group parameters are correct and reliable. For heavy natural uranium heaps, thermal group parameters are particularly important. In order to determine the better method for calculating the group parameters in the physical calculation of heavy water zero power reactor, two groups of diffusion parameters were calculated by three different sets of methods, respectively. Two groups of critical parameters