What is loss of coolant accident?

A loss of coolant accident (LOCA) is an accident scenario in which the coolant from a nuclear reactor's core is lost. The loss of coolant can occur due to various reasons such as a rupture in a coolant pipe, a breach in the reactor vessel, or a loss of electrical power. The loss of coolant can cause the reactor's fuel to overheat, leading to fuel cladding failure and melting of the core.

A LOCA is considered a severe accident because it can release radioactive materials into the environment. The release of radioactive materials can contaminate the air, water, and soil, and pose a risk to the health and safety of people living near the reactor.

To prevent LOCA, nuclear power plants are equipped with safety systems designed to detect coolant loss and take action to prevent the fuel from overheating. These systems include emergency coolant injection systems, coolant recirculation systems, and containment systems.

Other measures taken to mitigate LOCA include conducting regular safety drills and inspections, monitoring of coolant systems, and retrofitting older reactors with new safety features. Despite these measures, however, LOCA remains one of the most significant risks associated with nuclear power generation.