High Temperature Heat Exchanger and Component Test Laboratory – a Graded Approach

The Next Generation Nuclear Plant (NGNP) Project and the Nuclear Hydrogen Initiative (NHI) are U.S. Department of Energy programs that are responsible for the research, development, and testing of high-temperature gas-cooled nuclear reactor technologies and thermally driven hydrogen production methods. The two programs are related, in that the nuclear reactor will provide high-temperature heat, and the thermally-driven hydrogen plant will consume it. The nuclear reactor is envisioned as a largescale (500-600 MWth) high-temperature (750-900◦C) high-pressure (5-9 MPa) [1] helium-cooled unit that is capable of producing electricity or high-temperature heat. The hydrogen plant is less defined, but a number of methods are currently under investigation by the NHI including High-Temperature Electrolysis [2], the Hybrid Sulfur process[3], and the Sulfur-Iodine process[4]) and lower-temperature alternatives. A high-temperature heat transfer network (HEN) is needed to deliver thermal energy from the nuclear reactor to the hydrogen plant. The combination of a high-temperature gas-cooled nuclear reactor, a HEN, and a downstream user of high-temperature heat such as a nuclear hydrogen plant is known as the NGNP.