Japan's Nuclear Regulation Authority (NRA) opened a public comment period on July 30, 2026, on draft revisions that would tighten what reactor operators must show about how they intend to pay for tearing down a shut reactor, not merely that they have a plan on paper. The comment window runs to August 28, 2026, and the revised standards would take effect December 1, 2026.
Why the NRA is moving now
The trigger is a May 2026 report from the International Atomic Energy Agency's Integrated Regulatory Review Service (IRRS) mission to Japan, which recommended that the NRA "evaluate whether the financial measures set out in a research reactor's decommissioning plan are adequate and secured". Separately, operators raised their own complaints in a licensing-review dialogue the NRA has run since February 2026, asking for clearer wording on decommissioning-cost disclosures and on which equipment counts toward the "performance maintenance facilities" operators must keep running during teardown.
What the draft actually changes
The package covers three documents: amendments to the operating rules for test and research reactors and related regulations, a full rewrite of the decommissioning-plan examination standard for power reactors and test/research reactors, and a full rewrite of the standard for facilities that do not use the nuclear fuel materials listed under Article 41 of the law's enforcement order.
Substantively, the funding section of the examination standard would require research-reactor operators to show the total estimated cost of dismantling their facility and how that money will be raised, plus evidence the estimate is well-founded, for instance through backing documentation for the cost figures. Commercial power-reactor operators would instead need to certify they are continuously paying the reprocessing and decommissioning contribution levies required under Japan's 2005 nuclear-fuel-cycle funding law. The draft also states plainly, for the first time, that the list of "performance maintenance facilities" in the standard is illustrative rather than a closed list, and it adds a requirement that equipment installed solely for decommissioning work must come with a design, construction and inspection plan before it is judged as meeting that role. The NRA separately says items outside this package, still under review in its broader look at power-reactor licensing rules, will be examined for possible further rule changes later.
| Milestone | Date |
|---|---|
| NRA approves draft for public comment | July 29, 2026 |
| Public comment period opens | July 30, 2026 |
| Public comment period closes | August 28, 2026 |
| Revised rules take effect | December 1, 2026 |
What isn't settled yet
The draft's supplementary provisions state that any decommissioning-approval application still pending when the new rules take effect will continue to be processed under the existing rules. The package does not disclose any specific yen figures for decommissioning costs, current levy payments, or which reactors or facilities have applications in progress. Comments can be filed through the e-Gov portal or by post using a standard submission form, addressed to the Nuclear Regulation Authority's regulatory planning division.