The concept of "cleaning-up" in the context of fossil and nuclear technologies refers to the processes, techniques, and strategies employed to reduce, manage, or eliminate the environmental and health impacts caused by these energy sources. Fossil fuels, which include coal, oil, and natural gas, are major contributors to energy generation worldwide, but their extraction, processing, and combustion release large amounts of pollutants such as carbon dioxide, sulfur dioxide, nitrogen oxides, particulate matter, and heavy metals. These emissions contribute to air pollution, acid rain, global warming, and respiratory and cardiovascular diseases. Cleaning-up fossil fuel technologies primarily involves measures to capture, reduce, and neutralize these harmful by-products before they enter the environment. One of the key techniques in cleaning-up fossil fuel systems is flue gas desulfurization, commonly known as “scrubbing,” which removes sulfur dioxide from the exhaust gases of coal-fired power plants. Similarly, selective catalytic reduction is used to convert nitrogen oxides into harmless nitrogen and water, thereby controlling smog formation and acid rain. Particulate matter can be captured using electrostatic precipitators or baghouse filters, which prevent fine particles from being released into the atmosphere. Additionally, advances in carbon capture and storage (CCS) technology aim to trap