Nuclear meltdown of fission product radioactivity, by simple convection. The second test, deliberate shut-off of the secondary coolant loop that supplies the generators, caused the primary circuit to undergo the same safe shutdown. This test simulated the case of a water-cooled reactor losing its steam turbine circuit, perhaps by a leak. This is a list of the major reactor failures in which meltdown played a role: The China syndrome (loss-of-coolant accident) is a hypothetical nuclear reactor operations accident characterized by the severe meltdown of the core components of the reactor, which then burn through the containment vessel and the housing building, then
Nuclear meltdown nuclear meltdown in the absence of active safety measures, this is not a universal feature of civilian nuclear reactors. Much of the research in civilian nuclear reactors is for designs with passive nuclear safety features that may be less susceptible to meltdown, even if all emergency systems failed. For example, pebble bed reactors are designed so that complete loss of coolant for an indefinite period does not result in the reactor overheating. The General Electric ESBWR and Westinghouse AP1000 have passively activated safety systems. The CANDU reactor has two low-temperature and low-pressure water systems surrounding the fuel (i.e. moderator and