Decay heat

Decay heat is the residual heat generated by radioactive materials after a nuclear reactor has shut down. When nuclear reactions stop, the fission products (the elements created from splitting atoms) continue to release energy as they undergo radioactive decay. This heat can be substantial and needs to be managed to prevent overheating. Effective cooling systems are critical during this period to ensure safety, as this decay heat decreases over time but can remain significant for hours or even days after the reactor is no longer active.