Supercritical water reactor, a similar and perhaps even overlapping concept.

One next generation design, the supercritical water reactor, is even less moderated.

Supercritical water reactors (SCWRs) are promising advanced nuclear systems that offer similar thermal efficiency gains.

However some variants of the Generation IV reactor known as the supercritical water reactor may technically be considered fast neutron reactors.

The supercritical water reactor (SCWR) is a concept that uses supercritical water as the working fluid.

Recent research has focused on a cogeneration scheme using the waste heat from nuclear reactors, specifically the CANDU supercritical water reactor.

Behavior of supercritical water, important for the supercritical water reactors, differs from the radiochemical behavior of liquid water and steam and is currently under investigation.

In the proposed water-cooled supercritical water reactor (SCWR), the proportion of fast fissions may exceed 50%, making it technically a fast neutron reactor.

However the Generation IV reactor known as the supercritical water reactor with decreased coolant density may reach a hard enough neutron spectrum to be considered a fast reactor.

Current reactors stay under the critical point at around 374 C and 218 bar where the distinction between liquid and gas disappears, which limits thermal efficiency, but the proposed supercritical water reactor would operate above this point.