In the spent nuclear fuel storage pool (SFSP) of GA Siwabessy Multipurpose Reactor (GAS-MPR), there are three status of pool water level with unknown effect of water level on evaporation rate. This study aims to determine the effect of pool water level on the evaporation rate in the SFSP, so that it can be a consideration in minimizing the evaporation rate. A prediction of water evaporation rate can be explained as a diffusion model through a stagnant gas film. A numerical method, 4^th order Runge-Kutta was used to describe the concentration profile of water and air over a SFSP column to the top of the pool. The effect of the water level can be explained then. The various distance of the water to the pool top at constant water temperature and constant air temperature shows a result that the evaporation rate is decreasing while the distance of the water to the pool top is increasing. The investigation results conclude that the closer of the liquid-water surface to the gas-air flow, increases the evaporation rate. This approach can be applied in a SFSP that has an abundant amount of water, the water temperature remained constant by operation of the water-cooling system, air temperature, pressure, and relative humidity remained constant as well by the operation of ventilation and air conditioning (VAC) system. Those constant conditions were stated as normal operation in SFSP of GAS-MPR. In the case of abnormal conditions such as the VAC not operating or the water-cooling system not operating, there will be dynamics of pool water and air temperatures which require further modeling research.

在 GA Siwabessy 多用途反应堆 (GAS-MPR) 乏核燃料储存池 (SFSP) 中，池水位存在三种状态，水位对蒸发率的影响未知。本研究旨在确定池水位对 SFSP 蒸发率的影响，以便将其作为最小化蒸发率的一个考虑因素。水蒸发率的预测可以解释为通过停滞气膜的扩散模型。一种数值方法，^第4使用 Runge-Kutta 命令来描述从 SFSP 柱到水池顶部的水和空气的浓度分布。然后可以解释水位的影响。在恒定的水温和恒定的空气温度下，水到池顶的不同距离表明蒸发率减小，而水到池顶的距离增加。调查结果得出结论，液态水表面越靠近气体-空气流，蒸发率越大。这种方法适用于水量充足的SFSP，通过水冷系统运行保持水温恒定，通过通风和空调运行保持空气温度、压力和相对湿度恒定(VAC) 系统。这些恒定条件在 GAS-MPR 的 SFSP 中被声明为正常操作。在 VAC 不运行或水冷系统不运行等异常情况下，池水和空气温度的动态变化需要进一步建模研究。