Migration prevention system for radioactive wastewater of underground nuclear power plant

A migration prevention system for radioactive wastewater from an underground nuclear power plant, the underground nuclear power plant comprising a nuclear island comprising a reactor cavity, and the migration prevention system comprising:

• a protective structure surrounding the reactor cavity, the protective structure comprising an inner liner defining a wall of the reactor cavity, a drainage layer surrounding the inner liner, and an outer filling layer of rock fractures surrounding the drainage layer;
• and
• an impermeable layer surrounding the outer filling layer of rock fractures and defining a periphery of the nuclear island;
• wherein:
• the inner liner is configured to prevent exosmosis of radioactive wastewater of the reactor cavity;
• the drainage layer is configured to gather and drain seepage water;
• the drainage layer is disposed between the inner liner and the outer filling layer of rock fractures;
• and
• the impermeable layer is configured to isolate the nuclear island from natural underground water.