Policy and licensing / Japan

Japan: SMR policy and licensing

Selected federal, state, territory, and national measures whose official text was opened. This is not a complete list of laws, rules or programmes for any jurisdiction. A jurisdiction without a page here is not a finding that it has no policy, and these pages do not rate or prefer any jurisdiction. Nothing here implies that a project is eligible for, or approved under, any measure.

Laws, rules and executive directives

• Japan: Act on the Regulation of Nuclear Source Material, Nuclear Fuel Material and Reactors (Act No. 166 of 1957) · In effect
  核原料物質、核燃料物質及び原子炉の規制に関する法律 (昭和三十二年法律第百六十六号), promulgated 10 June 1957; current text as amended by Act No. 44 of 2023 (provisions enforced 6 June 2025) · National Diet of Japan; administered by the Nuclear Regulation Authority (原子力規制委員会) · affects: National reactor licensing
  Japan's Reactor Regulation Act requires Nuclear Regulation Authority permission to install a power reactor or a test and research reactor, with criteria covering peaceful use, technical and financial capability and NRA standards for location, structure and equipment. Since 6 June 2025 a power reactor needs NRA approval of a long-term facility management plan to run beyond 30 years, replacing the former 40-year period with one extension. It is a framework statute, not a project permission.
  Not approved or pending: Where any operating-period limit now sits after the 2025 change (outside this Act) was not reviewed. Cabinet Order designations of research-stage reactors, NRA review guides and fees were not reviewed. The Act names no project; permissions are separate NRA decisions.
• Japan: NRA rule on standards for the location, structure and equipment of commercial power reactors (NRA Rule No. 5 of 2013) · In effect
  実用発電用原子炉及びその附属施設の位置、構造及び設備の基準に関する規則 (平成二十五年原子力規制委員会規則第五号), promulgated 28 June 2013, in force 8 July 2013; current text as last amended by NRA Rule No. 7 of 2026 (in force 11 September 2026) · Nuclear Regulation Authority (原子力規制委員会) · affects: Siting
  Japan's Nuclear Regulation Authority rule on the location, structure and equipment of commercial power reactors requires seismically important facilities to be built on ground where no displacement is likely and that can support them, and sets earthquake and tsunami protection standards. It applies to commercial power reactors only and approves no site.
  Not approved or pending: Does not cover test and research reactors such as the HTTR, which have a separate NRA rule that was not reviewed. NRA review guides on faults, ground motion and siting were not reviewed. The rule approves no site.

Bills, proposed rules and consultations

• None recorded in this pilot.

Funding and support programmes

• Japan: Long-Term Decarbonization Power Source Auction (capacity market, from FY2023) · In effect
  長期脱炭素電源オークション (Long-Term Decarbonization Power Source Auction), part of the capacity market operated by OCCTO since FY2023; FY2026 bidding round governed by OCCTO's final application rules of 2 September 2026 · Organization for Cross-regional Coordination of Transmission Operators (OCCTO), under guidelines of the Agency for Natural Resources and Energy (METI) · affects: Project funding, Utility cost recovery
  Japan's Long-Term Decarbonization Power Source Auction, run by OCCTO since FY2023, pays winning new or replacement low-carbon capacity a fixed capacity revenue, and nuclear new build or replacement of at least 100,000 kW is eligible. Under OCCTO's final FY2026 rules, capacity-revenue support normally lasts 20 years, beginning in the fiscal year after supply starts; nuclear bidders may request a longer period in whole years up to 30 years. It is a support mechanism, not an award to any project.
  Not approved or pending: The ANRE auction guideline itself was not readable; the operative text is OCCTO's final FY2026 application rules of 2 September 2026. No nuclear award or bid is recorded here, and no SMR project is named. Plants below 100,000 kW sending-end capacity are outside the eligibility table read.

No award or selection recorded.

Recorded applications and decisions for tracked projects and designs in Japan

Project and design permissions are separate from the general measures above.

Other applications and decisions

• NRA decision to grant the HTTR installation-change permit — HTTR test reactor with planned hydrogen coupling, Oarai
  Other regulatory action · Issued / approved · NRA · decided 3 Jun 2020 · submitted 26 Nov 2014
  On 3 June 2020 the Nuclear Regulation Authority decided that the application to change the HTTR installation at Oarai meets the permit criteria and that the installation-change permit shall be granted under article 26(1) of the Reactor Regulation Act. The application was received on 26 November 2014. The draft letter has a blank number and a blank date, so no permit number is stored. This decision is not an operating licence and is distinct from the July 2021 restart.
  Sources: NRA commission paper deciding the HTTR installation-change permit (3 June 2020)

What this review has read for Japan

As of 18 Oct 2026. Bounded review concluded. A bounded review of three national source classes, not a complete list of laws, rules or programmes. Coverage for every reviewed country.

• Controlling reactor licensing framework: Evidence read. The Reactor Regulation Act was read in the official e-Gov database in its current text and its prior revision, which shows that the 2023 decarbonized power supply amendments replaced the 40-year operating period article with long-term facility management plans from 6 June 2025; the Electricity Business Act was not reviewed.
• Siting restrictions or rules: Evidence read. The Nuclear Regulation Authority rule on location, structure and equipment standards for commercial power reactors was read in the e-Gov database; the separate rule for test and research reactors and the NRA's non-binding review guides were not reviewed.
• Directly relevant support measures: Evidence read. OCCTO's final FY2026 application rules of 2 September 2026 and its July 2026 overview of the long-term decarbonization auction were read; the Agency for Natural Resources and Energy guideline and committee papers on METI sites refused access, and the 2026 next-generation reactor development support is recorded separately as a programme.

Sources read (7):

• laws.e-gov.go.jp/api/1/lawdata/332AC0000000166 · checked 2026-10-18
• laws.e-gov.go.jp/api/2/law_revisions/332AC0000000166 · checked 2026-10-18
• laws.e-gov.go.jp/api/2/law_data/332AC0000000166_20250601_504AC0000000068?la… · checked 2026-10-18
• laws.e-gov.go.jp/api/1/lawdata/425M60080000005 · checked 2026-10-18
• laws.e-gov.go.jp/api/2/law_revisions/425M60080000005 · checked 2026-10-18
• www.occto.or.jp/assets/260902_boshuyoukou_long_2026.pdf · checked 2026-10-18
• www.occto.or.jp/assets/various/capacity-market/youryou_setsumeikai/202607_y… · checked 2026-10-18

Sources that could not be read (2):

• www.enecho.meti.go.jp/category/electricity_and_gas/electric/summary/regulat… · checked 2026-10-18 · not readable: HTTP 403 (ANRE site refuses the request).
• www.meti.go.jp/shingikai/enecho/denryoku_gas/jisedai_kiban/stable_power_sup… · checked 2026-10-18 · not readable: HTTP 403.