SMR developments: June 2026
29 recorded developments dated June 2026: 1 permission or environmental decision, 17 project developments, 2 announcements, 9 policy steps.
Entries are placed by their recorded date, not by when SMRMap added them. Entries dated only to a quarter or year are not assigned to a month. Each entry is dated when the development happened unless its label says otherwise, such as “Announced” or “Report dated”. A date recorded only to a month, quarter or year is shown that way. Targets are plans, not achievements or commitments.
Recorded developments
· Recorded development
Pele core stacking complete (BWXT) #
· Signed
Signed: Iowa House File 2757: nuclear generation tax treatment and workforce fund #
The governor's letter says House File 2757 is approved on 1 June 2026. No separate effective-date clause was stored.
· Recorded development
SSM opinion on the ReFirm Målma government-approval application #
SSM's 3 June 2026 opinion says the ReFirm Målma AB government-approval application is high-level and that some statements are deficient or incorrect. SSM says no Nuclear Activities Act licence application has been filed, and that the government has to decide whether this application level is reasonable. The opinion is not a permit and not a refusal.
· First criticality
Antares Mark-0 zero-power criticality #
Zero-power fueled criticality at INL. Not grid connection.
· Took effect
Took effect: Croatia: Law on the Development of Nuclear Energy for Civil Purposes (NN 55/2026) #
Eighth day after publication (Article 15).
· First concrete
First concrete poured for Uzbekistan's first RITM-200N unit #
Uzbekistan's atomic energy agency says first concrete was poured into the first SMR unit's foundation on 4 June 2026, after the regulator decided to licence its construction. This covers the first SMR unit only; the second unit has no reported construction licence.
Checking notes
Uzatom reports that at a ceremony on 4 June 2026 in Farish district, first concrete was poured for the foundation of the first unit with a RITM-200N reactor: 133 cubic metres at the initial stage of more than 10,000. It says the pour gives the plant official under-construction status. The regulator decided the same day to issue the unit's construction licence. World Nuclear News dates its report 5 June.
· Construction permission recorded
Construction permission recorded: Licence for construction of an NPP power unit with a RITM-200N reactor #
Council of the Committee decided 'today' (item dated 2026-06-04) to issue the licence for construction of one power unit (singular 'энергоблока'); the Committee's notice states no licence number or holder. Covers one of the two RITM-200N units. Uzatom states that the licence was issued to the state institution Directorate for the Construction of the Nuclear Power Plant; the licence number is not published.
· Recorded development
Government receives Blykalla's state-support application for Norrsundet #
· Recorded development
NRC preliminary feedback on its observation of Aurora-INL DOE submittals #
On 5 June 2026 the NRC sent Oklo preliminary feedback from observing DOE authorization submittals, including a preliminary documented safety analysis. The letter says DOE's own determination is independent and that a final audit report will follow. It does not approve the analysis and does not issue a licence.
· Recorded development
DOE approves the Unity critical experiment documented safety analysis #
DOE's Reactor Pilot Program update of July 2026 lists the Deployable Energy preliminary documented safety analysis as approved on 22 May 2026 and the documented safety analysis as approved on 11 June 2026, before criticality on 30 June 2026. The slides do not reproduce the approval documents. A safety-analysis approval for a zero-power test does not authorize a later power reactor.
· Took effect
Took effect: New York PSC nuclear reliability backbone process #
The order prints Issued and Effective June 11, 2026. Staff's white paper is due within five months. That period is not stored as a calendar day.
Announced · Announcement
Oklo announces DOE approval of the Aurora-INL preliminary safety analysis #
Company statement of 11 June 2026. Oklo says DOE's Idaho Operations Office approved the preliminary documented safety analysis for the Aurora powerhouse at Idaho National Laboratory under the Reactor Pilot Program. The DOE approval document was not opened; an NRC audit plan confirms only that Oklo submitted the analysis to DOE. A preliminary safety analysis approval is not authority to load fuel or operate.
· Recorded development
Government receives Studsvik's state-support application covering Valdemarsvik and Nyköping #
· Comment period closed
Comment period closed: Proposed licensing requirements for microreactors and comparable reactors #
NRC proposal published 1 May 2026; the comment period closed on 15 June 2026. It is not in effect.
· Passed
Passed: Puerto Rico House Bill 1092 (2026): nuclear energy and small modular reactors in the energy policy act #
The House passed the bill in final vote on 15 June 2026, 35 in favour and 11 against. It had its first reading in the Senate and was referred to the Senate Government Committee on 19 June 2026. House passage is not enactment.
· Regulatory step
Ministry requests more information on Stellaria's INB Alpha application #
Following ASNR's analysis, the ministry asked Stellaria on 16 June 2026 to complete its INB Alpha file. ASNR's technical review is suspended until the complements arrive. A request for information, not a refusal or an authorization.
Checking notes
After ASNR's analysis, the ministry's nuclear-safety mission (MSNR) requested complements from Stellaria on the INB Alpha creation-authorization application on 16 June 2026; ASNR's technical review is suspended until they are provided.
· Recorded development
NRC issues the KRONOS review schedule #
NRC milestone marked actual: review schedule established and schedule letter issued. The later 2027 dates on that schedule are targets.
· Took effect
Took effect: Sweden: Act on Government Approval of Nuclear Facilities (SFS 2026:585) #
Transitional provision 1; point 2 allows application to applications filed after 10 March 2026.
· Provision took effect
Provision took effect: Sweden: Act on Government Approval of Nuclear Facilities (SFS 2026:585) #
Companion Environmental Code amendments (SFS 2026:586) to chapter 17 ss. 1 and 6 a in force 17 June 2026.
· Provision took effect
Provision took effect: Sweden: Act on Nuclear Activities (SFS 1984:3, lag om kärnteknisk verksamhet) #
Amendments by SFS 2026:587 (licensing split, advance rulings on design) in force 17 June 2026 per their transitional provisions.
Announced · Announcement
Elementl announces Letart BWRX-300 proposal #
Named host and early works agreement; no construction permit inferred.
· Contract
Terrestrial Energy RELLIS ground lease #
Ground lease and research agreements for about 77 acres. Not a reactor licence.
· First criticality
Ward 250 zero-power criticality #
Zero-power fueled criticality at Utah San Rafael Energy Lab.
· Failed
Failed: Arizona S.B. 1418, vetoed: corporation commission and small modular reactors #
The fact sheet prints Vetoed by the Governor 6/19/26. Senate Research prepared the sheet on 25 June 2026. The governor's 19 June 2026 action page lists SB 1418 under Vetoed.
Announced · Recorded development
Williams Treaties First Nations announce C$700 million investment in Darlington new nuclear #
Seven First Nations will lend C$700 million to Darlington New Nuclear Project LP for construction of the first BWRX-300 unit; the loan converts to equity once all four units are built. Federal and Ontario programmes guarantee the financing. The stake is in the four-unit new-build project, not the existing Darlington station, and no ownership percentage is published.
Checking notes
Seven Williams Treaties First Nations announced a C$700 million investment, structured as a loan to Darlington New Nuclear Project LP for construction of the first of four BWRX-300 units, converting to equity once all four are built. Federal and Ontario Indigenous loan-guarantee programmes support about C$715 million in financing.
· Recorded development
NRC formal review activities begin for the KRONOS construction permit application #
· Recorded development
Swedish Government decides to take a 60% stake in Videberg Kraft #
The Government decided that the state will own 60% of Videberg Kraft, with Vattenfall and Industrikraft at 20% each; formal transfer is expected in the second half of 2027 and the negotiated support terms go to the European Commission for state-aid review. Not an investment decision, permit or construction start.
· Recorded development
Ward 250 passive-safety demonstration: shutdown with all active cooling off and simulated total loss of power #
Supplies the date the IAEA outlook omits for the loss-of-forced-cooling demonstration (company statement).
· First criticality
Unity criticality demonstration #
DOE fact sheet dates the INL demonstration 30 Jun 2026. Electrical output not stated.
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