A correspondence has been received in reference to a recently published article titled “On the decision making criteria for cis-lunar reference scenarios”. The intent of the paper was to demonstrate: (i) a novel methodology for calculating the dose from solar particle events (SPEs), and (ii) the impact of the SPE parametric model, shield thickness, dose metric, and radiation transport code on choosing a worst-case scenario. This effort assumed a spherical, aluminum spacecraft with an internal diameter of 3.8 m and with varying wall thickness ranging from 2 to 10 cm. A brief component of this article compared the dose from several solar particle events (SPEs) inside the spherical spacecraft geometry as calculated with Monte Carlo radiation transport code MCNPX and the on-line tool OLTARIS. In this comparison, the MCNPX simulation parameters assumed a volume-averaged dose while OLTARIS calculations assumed a point-dose estimate at the center of the spherical geometry. These modeling assumptions were detailed in the initial publication. The differences in the neutron, proton, and light-ion fluences and doses obtained between both codes were generally attributed to differences transport methodologies, nuclear physics models, boundary condition setup and detector regions. The commentary received demonstrated when both codes used a point-detector geometry and/or volume-averaged geometries, the two would yield similar proton fluences. This is a worthwhile observation that further emphasizes the impact of modeling assumption. The commentary further suggested however that the volume-averaged dose results “artificially reduced” estimates and that it was both “misleading” and “not-applicable” for use in storm shelter design. The response presented here will reiterate the context of the initial assumptions made, demonstrate the variability in point-dose estimates relative to a volume-averaged dose estimate, state why a volume-averaged estimate is equally applicable in this context, and lastly reference other factors that can give rise to increased uncertainty.

已收到有关最近发表的标题为“关于顺-月参考情景的决策标准”的文章的来信。本文的目的是证明：（i）一种从太阳粒子事件（SPE）计算剂量的新颖方法，以及（ii）SPE参数模型，屏蔽层厚度，剂量度量和辐射传输代码对辐射的影响选择最坏的情况。这项工作假设球形铝质航天器的内径为3.8 m，壁厚在2至10 cm之间变化。本文的一个简短组成部分比较了用蒙特卡罗辐射传输代码MCNPX和在线工具OLTARIS计算的球形航天器几何形状内几个太阳粒子事件（SPE）的剂量。在这个比较中 MCNPX模拟参数假定为体积平均剂量，而OLTARIS计算假定为球形几何体中心的点剂量估计。这些建模假设在初始出版物中进行了详细说明。两种密码之间中子，质子和光离子注量和剂量的差异通常归因于差异传输方法，核物理模型，边界条件设置和探测器区域。收到的评论证明，当两个代码都使用点检测器几何和/或体积平均几何时，两者将产生相似的质子注量。这是一个值得观察的发现，进一步强调了建模假设的影响。然而，评注进一步表明，体积平均剂量得出的结果是“人为减少”的估计值，用于防风雨棚设计既“误导”又“不适用”。此处提出的答复将重申所做的初始假设的背景，论证点剂量估算相对于体积平均剂量估算的可变性，说明为何体积平均估算在此情况下同样适用，最后参考其他因素这会增加不确定性。