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Policy and licensing / Japan

Japan: Act on the Regulation of Nuclear Source Material, Nuclear Fuel Material and Reactors (Act No. 166 of 1957)

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.

Category
Laws, rules and executive directives
Status
In effect
Instrument
statute · 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)
Issued by
National Diet of Japan; administered by the Nuclear Regulation Authority (原子力規制委員会)
Jurisdiction
Japan
Affects
National reactor licensing
Effective date
Not recorded
Expiry or completion
None recorded
Operative text
e-Gov law database: 核原料物質、核燃料物質及び原子炉の規制に関する法律 (Act No. 166 of 1957), current text (e-Gov consolidated text, current enforced revision of 6 June 2025 (Act No. 44 of 2023))
Record reviewed · next review
2026-10-18 · 2027-04-18 (dates our review of this record; not a statement of the measure's present legal effect)

Legal and geographic scope

National statute regulating nuclear source and fuel material and reactors. Article 23 requires Nuclear Regulation Authority (NRA) permission to install a reactor other than a power reactor (test and research reactors, including ship reactors), with criteria in Article 24. Article 43-3-5 requires NRA permission to install a power reactor; the application states reactor type, thermal output and number of units, location, the location, structure and equipment of the reactor facility and other items. Under Article 43-3-6 the NRA may grant permission only if criteria are met, including that location, structure and equipment meet standards in NRA rules; a type certificate for specified equipment is deemed to meet the technical part of that standard. Since 6 June 2025 Article 43-3-32 requires NRA approval of a long-term facility management plan before a power reactor is operated beyond 30 years from its first confirmation, in periods of up to ten years; before then the same article set a 40-year operating period, extendable once by up to 20 years with NRA approval.

Not approved or still 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.

Dated lifecycle

Definitions in this instrument

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