📖 High Performance Light Water Reactor is a reactor concept of the 4th generation which is cooled and moderated with water at supercritical pressure. Water as the working fluid is guided three times upward and downward through the core and finally heats up to 500°C.The fluid temperature at the outlet of the first upwards flow, the so-called “evaporator‟. The presence of the wire inside the fuel assembly results in a strong flow mixing and sweeping effects among sub-channels. The values of the “wire factor” indicate that the wire spacer can improve the heat transfer at DHT conditions.