The high-temperature test reactor (HTTR) is a graphite-moderated gas-cooled research reactor in Ōarai, Ibaraki, Japan operated by the Japan Atomic Energy Agency. It uses long hexagonal fuel assemblies, unlike the competing pebble bed reactor designs.

HTTR first reached its full design power of 30 MW (thermal) in 1999. Other tests have shown that the core can reach temperatures sufficient for hydrogen production via the sulfur-iodine cycle.

High-temperature engineering test reactor

Technical details

The primary coolant is helium gas at a pressure of about 4 MPa, the inlet temperature of , and the outlet temperature of . The fuel is uranium oxide (enriched to an average of about 6%).

High-temperature engineering test reactor

See also

Very-high-temperature reactor

Hydrogen economy

External links

HTTR at the JAEA website.

High-temperature engineering test reactor

Graphite moderated reactors

Nuclear technology in Japan

Ōarai, Ibaraki