Geoenergy technologies, including the Underground Coal Gasification (UCG), are currently being considered as possible solutions for reducing emissions of CO₂ and other gases to atmosphere and at the same time, provide sustainable sources of low-carbon energy. In this paper, a flexible risk assessment methodology for UCG technology is presented, based on an established methodology for radioactive waste repositories. The assessment methodology can be applied at any stage in a project, between initial planning and final site abandonment. Central to the approach is the analysis of scenarios, which represents a “source-pathway-receptor” combination and its evolution. Here, a Reference Scenario (RS) and several Alternative Scenarios (AS) are developed and analysed using a numerical model. Results of the RS suggest that contaminant concentrations at an evaluation point are far below any level that could reasonably be detected. In some AS, the calculated concentrations showed an increasing trend at the end of the assessment period, potentially approaching levels that conceivably could be detected. However, as such cases are unexpected and pessimistic, their inclusion is to illustrate worst cases that could happen, rather than to give predictions. An illustrative application demonstrates that plausibly the risks of groundwater contamination from a UCG site should be very low if the site is developed and operated appropriately. The outcomes from applying the numerical model are intended to demonstrate how the methodology and the numerical model can be readily adapted to different sites.

包括地下煤炭气化 (UCG) 在内的地能技术目前正被视为减少 CO _{2排放的可能解决方案}和其他气体排放到大气中，同时提供可持续的低碳能源。在本文中，基于放射性废物处置库的既定方法，提出了一种灵活的 UCG 技术风险评估方法。评估方法可以应用于项目的任何阶段，从最初的规划到最终的场地废弃。该方法的核心是对场景的分析，它代表了“源-通路-受体”组合及其演变。在这里，使用数值模型开发和分析了一个参考场景 (RS) 和几个替代场景 (AS)。RS的结果表明评估点的污染物浓度远低于可以合理检测到的任何水平。在一些 AS 中，计算出的浓度在评估期结束时呈上升趋势，可能接近可以检测到的水平。但是，由于此类情况是出乎意料和悲观的，因此将其纳入是为了说明可能发生的最坏情况，而不是给出预测。一个说明性的应用表明，如果场地开发和运营得当，UCG 场地的地下水污染风险应该非常低。应用数值模型的结果旨在证明该方法和数值模型如何可以很容易地适应不同的地点。