Programmes and agreements / prg-jp-htgr-demonstration-reactor
Japan's HTGR demonstration reactor programme (METI/ANRE, MHI core company, site not selected)
Japan's government plans a high-temperature gas-cooled demonstration reactor for hydrogen production, targeted to operate in the 2030s, METI's ANRE selected MHI in July 2023 as core company for its design and construction. The conceptual specification is about 200 MWt. Site selection and the implementing body have not been decided, although Ibaraki Prefecture has asked to host it.
- Type
- Government programme
- Countries concerned
- Japan
- Participants and roles
- Government: Agency for Natural Resources and Energy (ANRE), METI
- Developer or vendor: Mitsubishi Heavy Industries
- Research: Japan Atomic Energy Agency
- Other participant: Ibaraki Prefecture
- Designs named
- HTGR demonstration reactor (MHI basic design) (no design profile)
- Scale as stated
- one demonstration reactor, reactor thermal output 150-250 MW (conceptual specification about 200 MWt) · 1 unit stated
- Announced or first reported
- Jul 2023
- Status
- Active
Operation targeted in the 2030s, site selection and implementing structure still listed as open tasks (2026 roadmap). Ibaraki Prefecture asked the national government in June 2025 and June 2026 to… - Confidence
- medium
- Last checked
- 2026-10-14 (record review date, not proof of current activity)
Related deployment projects
- HTTR test reactor with planned hydrogen coupling, Oarai — Operating · Japan
Sources
- WNN: MHI to lead development of Japanese HTGR (reputable_press, accessed 2026-10-02)
- JAEA: amendment to HTTR licence application for hydrogen plant connection (company_primary, accessed 2026-10-02)
- JAEA: HTTR hydrogen-coupling status and schedule (symposium slides, 7 August 2026) (company_primary, accessed 2026-10-06)