We have calculated the amount of radioactive heat production (RHP) that could possibly prevent the postulated underground ocean of Enceladus from freezing. An internal heat source is necessary to justify the observed heat output from Enceladus and to allow the tidal dissipation heating models to work. Also based on the terrestrial evidence, we have assumed that the most common radiogenic element that can produce such internal heat is ²³⁸U. Our results show that a minimum amount in the range 38.10–76.59 ppm of ²³⁸U, averaged over the whole mass of Enceladus, is necessary to obtain the required RHP. The range of values increases to 63.60–127.70 ppm if we consider only the mass of the rocky portion and 2890–5775 ppm if we consider the mass of the rock + ice portion of Enceladus just below the southern polar area. Even in the latter case, the concentration of uranium is still well below the amount found in high-grade ore on Earth.

我们已经计算了可能防止土卫二假设的地下海洋冻结的放射性热量产生量 (RHP)。内部热源是必要的，以证明从土卫二观察到的热量输出是合理的，并允许潮汐耗散加热模型工作。同样基于陆地证据，我们假设可以产生这种内部热量的最常见的放射成因元素是²³⁸ U。我们的结果表明，在 38.10-76.59 ppm 范围内的²³⁸U 是土卫二整个质量的平均值，是获得所需 RHP 所必需的。如果我们只考虑岩石部分的质量，数值范围会增加到 63.60-127.70 ppm，如果我们考虑南极地区正下方土卫二的岩石 + 冰部分的质量，数值范围会增加到 2890-5775 ppm。即使在后一种情况下，铀的浓度仍远低于地球上高品位矿石中的含量。