The supercritical water-cooled reactor concept is a high-temperature, high-pressure water-cooled reactor that operates above the thermodynamic critical point of water (374°C, 22.1 MPa or 705°F, 3208 psia). The system may have a thermal or fast neutron spectrum, depending upon the core design. The focus in the United States. will be only on the thermal-spectrum version. The SCWR holds the potential for significant advantages compared to state-of-the-art LWRs due to: significant increases in thermal efficiency relative to current generation LWRs (the efficiency of a SCWR can approach 45%, compared to 33-35% for LWRs); lower coolant mass flow rate per unit core thermal power leading to a reduction in the size of the reactor coolant pumps, piping and associated equipment, and a reduction in the pumping power; lower coolant mass inventory; elimination of discontinuous heat transfer regimes within the core; and the elimination of steam dryers, steam separators, re-circulation pumps, and steam generators. Therefore, the SCWR will be a simpler plant with fewer major components.