Savannah River Nuclear Solutions (SRNS), the management and operating contractor of the US DoE Savannah River Site (SRS), announced the completion of downblending of Swiss plutonium that was brought to (SRS) in 2016. According to SRNS, the program of managing the Swiss material began in 2022.

What SRNS calls "downblending" is, in fact, a process of mixing plutonium with adulterating material to complicate chemical separation of plutonium. This process does not change the isotopic composition of plutonium the way the downblending of highly-enriched uranium does. (This method was developed as part of the "dilute and dispose" program of eliminating surplus plutonium, which was cancelled by an executive order is May 2025.)

The Swiss government reported in 2016 that the shipment included about 20 kg of plutonium.

The Swiss plutonium is designated in the United States as "gap material," as it is not covered by the programs that repatriate US or Russia-origin fissile material. According to SRNS, the Savannah River Site "has received gap material from six countries" so far. The material is stored in the K Area Complex and is "planned to be downblended over the next couple of years."

In addition to Switzerland, the five countries that have sent their plutonium to SRS as part of the gap material program are Sweden (2009-2012), Belgium (2014), Italy (2014), Germany (2016), and Japan (2016).

On 29 June 2026, the Urenco Group issued a statement announcing that the UK Government formally requested the company to support its effort "to re-establish a nuclear fuel cycle for reactor fuel for defence purposes." The UK Government announced its intent to re-establish this program in November 2024.

This announcement is part of a broader development that could significantly change how the United Kingdom as well as other states handle the issue of the production of fissile materials for defense purposes.

Centrus Energy, a US company that operates the American Centrifuge Plant in Piketon, OH, signed a contract that finalized the terms of the $900 million order it received from the Department of Energy in January 2026.

The first HALEU-related award to Centrus, announced in 2019 (subsequently extended), allowed the company to start production in 2023 and produce the first 900 kg of HALEU in 2025. The company press release mentions the "cumulative total of more than 1,900 kilograms produced over the life of the [2019] contract," but it is not clear if an additional 1,000 kg of HALEU has actually been produced since June 2025.

Under the new contract Centrus plans to expand its enrichment capacity at the plant in Piketon to 12 tonnes of HALEU annually (earlier plans mentioned 6,000 kg of HALEU a year). It appears that the plant will be producing LEU as well. The first new capacity is expected to come online in 2029.

The US Department of Energy announced that it is conducting negotiations with five companies "to explore if nearly 20 metric tons of surplus plutonium materials could be transformed into advanced nuclear fuel or used in advanced reactor research and development." The companies earlier selected by the DoE are Exodys Energy, Flibe Energy, Oklo, SHINE Technologies, and Standard Nuclear. The negotiations are part of the Surplus Plutonium Utilization Program, which was established in May 2025. In October 2025, the DoE issued a request for proposals, in which it announced the intent to offer 19.7 metric tons of surplus plutonium to the industry.

The update of the installed enrichment capacity, published as part of the annual update of the data on the stocks of fissile materials, does not fully reflect the plans of various companies to expand installed enrichment capacity. This post summarizes the information about these plans.

French group Orano has two expansion projects. One is to increase the capacity of the Georges Besse II plant in France "by more than 30%, corresponding to 2.5 million SWUs." The project will increase the capacity of the plant from the current 7,500 tSWU/y to 10,000 tSWU/y. The production is expected to start in 2028.

In the United States, Orano plans to build a new enrichment facility in Oak Ridge, Tennessee. According to the application Orano submitted to NRC, the planned capacity of the plant is 7400 tSWU/y.

Another European company, Urenco, in April 2026 completed the first phase of the expansion of its US plant in Eunice, NM, which brought the capacity of the plant to 4,650 tSWU/y. It is expected to reach 5,000 tSWU/y in 2026-2027. The company also announced a plan to add another 2,100 tSWU/y to the plant in the future, bringing the total capacity to 7,100 tSWU/y.

In Europe, Urenco has several expansion projects. The plant in Almelo, the Netherlands, is adding capacity to reach about 6,600 tSWU/y by 2030 (from 5,100 tSWU/y in 2025). The capacity of the plant in Gronau, Germany, will increase from the current 3,400 tSWU/y to 3,700 tSWU/y in 2026-2027. The Urenco plant in Capenhurst, the United Kingdom, plans to add a line that will produce up to 27 tonnes of HALEU annually starting in 2031.

Centrus, which operates the American Centrifuge Plant at Piketon, Ohio, announced the plan to install a new cascade of 120 centrifuges, apparently at Piketon. The cascade is expected to produce 6,000 kg of HALEU a year. The existing cascade of 16 centrifuges is said to be capable of producing 900 kg of HALEU annually.

Another US company, BWXT, was awarded a contract to establish the supply of unobligated enriched uranium. As part of this effort, the company plans to build a pilot enrichment facility, known as Domestic Uranium Enrichment Centrifuge Experiment (DUECE), in Erwin, TN. The capacity of the plant is not known.

Global Laser Enrichment has a plan to build the Paducah Laser Enrichment Facility (PLEF) in Paducah, Kentucky. The plant will use the Silex laser separation technology. The projected capacity of the plant has not been announced.

A new entrant to the US enrichment market, General Matter, expressed interest in the Paducah site as well. The company leased a parcel of land there from the DoE together with a stock of depleted uranium. It appears that the company is planning to produce HALEU.

As of the beginning of 2025, the global stockpile of weapon-usable fissile materials--about 1,810 metric tons (MT)--included about 1,240 MT of unirradiated highly enriched uranium (HEU) and about 570 MT of separated plutonium. A significant fraction of the global stock of each of these fissile materials is either in nuclear weapons or available for use in weapons. Material is considered not available for weapons when it is either produced outside weapon programs or produced in a weapon program but covered by an obligation, whether by agreement or by national declaration, not to use it in weapons. These estimates have been posted on the IPFM site and published in the "World nuclear forces" chapter of SIPRI Yearbook 2026.

Most of the unirradiated HEU--about 1,100 MT--is in weapons or available for use in weapon programs. The 140 MT of HEU unavailable for weapons includes material reserved for naval and research reactors, US HEU in the downblending queue, as well as an estimated 4 MT of HEU in non-nuclear weapon states. All HEU in non-nuclear weapon states and 3.8 MT of the material in France that it declared civilian are under international safeguards (IAEA and Euratom respectively). The rest of the HEU is not under safeguards or monitoring. This includes the 501 kg of HEU declared by the United Kingdom as civilian, since this material is not under international safeguards.

In contrast with HEU, most of separated plutonium--430 MT out of the total 570 MT--is not available for weapons. This material includes about 47 MT of plutonium owned by non-weapon states (44.4 MT of it by Japan), as well as 116.8 MT and 99.5 MT of plutonium declared as civilian by the United Kingdom and France respectively.

Also in this category is 116.1 MT of separated plutonium out of Russia's total stock. This includes 66.1 MT of material declared as civilian, 25 MT of weapon-origin plutonium that Russia pledged not to use for military purposes as part of the 2010 Plutonium Management and Disposition Agreement, as well as 15 MT of weapon-grade plutonium that is under obligation not to use it in weapons under the US-Russian 1997 agreement on plutonium production reactors.

The US stock of separated plutonium that is not directly available for weapons consists of 49.4 MT of material, most of which is excess material still in weapon components. The estimated 10 MT of reactor-grade plutonium owned by India is not considered directly available for weapons as this material is used in the fuel of India's first breeder reactor. China stopped submitting reports on the status of its civilian plutonium stock after 2016, when it declared having 40.9 kg of material.

Of the 430 MT of plutonium not directly available for weapons, 165 MT is under international safeguards or monitoring. This includes all 47 MT owned by non-nuclear weapon states, 3 MT of US plutonium, and 0.4 MT of India's plutonium under IAEA safeguards. 99.25 MT of French plutonium is under Euratom safeguards.

About 15 MT of Russia's weapon-grade plutonium, separated after 1996, is subject to US monitoring in accordance with the 1997 US-Russian agreement. While it is unlikely that the United States conducts inspections at this time, the agreement apparently remains in force (at least as of 1 January 2025).

Of the estimated 140 MT of plutonium that is in weapons or available for weapons, the largest stocks are those of Russia (about 88 MT) and the United States (38.4 MT). Stocks of other nuclear armed states are much smaller--about 6 MT in France, 3.2 MT in the UK, about 3 MT in China. Other states have less than a metric ton each.

Production of military fissile materials continues in India, which is producing plutonium for weapons and HEU for naval propulsion, Pakistan, which produces plutonium and HEU for weapons, Israel, which is believed to produce plutonium. North Korea has the capability to produce weapon-grade plutonium and highly-enriched uranium.

In the 1990s, the United States and Russia made a commitment not to use some of their weapon-origin and weapon-grade material for weapons and eliminated some of that material. This effort, however, has stalled. Russia formally ended its participation in the Plutonium Management and Disposition Agreement (PMDA) in October 2025. Russia suspended the implementation of this program in 2016 and has been using civilian plutonium to fuel its breeder reactors instead of weapon-grade plutonium as envisioned by PMDA.

The United States terminated the surplus plutonium dilute and dispose program in May 2025 and made the surplus plutonium available to the industry. The United States uses some weapon-origin and weapon-grade HEU in the fuel of naval and research reactors. It also continues to downblend some non-weapon HEU.

Meanwhile, France explicitly stated that it will use its weapon-origin material that was released during the downsizing of its arsenal in the 1990s to produce new nuclear weapons as necessary.

Note: The difference in the plutonium inventory numbers between the IPFM site and the SIPRI data is due to accounting for the civilian plutonium other than that owned by Japan.

The US Nuclear Regulatory Commission received an export license application XSNM3864 to allow Mirion Industries Corporation to supply radiation detection units to Westinghouse Electric China for use in AP1000 reactors that the company builds there.

The license application specifies that the equipment will include "up to 15 Intermediate Range Core Detectors, each containing up to 6 grams of U-235." The total amount of HEU in the application is 90 g, maximum enrichment is listed as 93.19%, with a U-235 content of 83.87 g.

On 3 June 2026, the leader of North Korea visited a new enrichment facility. According to analysis published by VERTIC, the facility is a new enrichment plant in Yongbyon, described in North Korean media as Nuclear Materials Construction Factory. The IAEA also stated that the layout of the facility shown on photographs is consistent with the building in Yongbyon. The building, in turn, is similar to the enrichment facility in Kangson.

VERTIC estimates that after the addition of this new facility to the existing ones in Yongbyon and Kangson the total enrichment capacity in DPRK reached about 100 tSWU/year (90,900 kgSWU/year in VERTIC's estimate). VERTIC estimates that this corresponds to the capability of producing about 375 kg or weapon-grade HEU a year.

On 26 May 2026, the Ministry of National Defense of the Republic of Korea presented the "Basic Plan for the Development of the Republic of Korea's Nuclear-Powered Submarines" (the press-release in English, translated by Naval News). The document describes the key parameters of the program that aims to build nuclear-powered submarines.

According to the plan, the future submarines will use low-enriched uranium fuel while enabling "long-cycle operation in order to minimize nuclear fuel replacement." The submarines will be developed and built in the Republic of Korea. The first submarine is expected to be launched in the mid-2030s and commissioned into service after the late 2030s.

The document also states that

the Republic of Korea will faithfully fulfill its non-proliferation obligations throughout the entire process of securing and managing low-enriched uranium, the nuclear fuel required for the propulsion system of nuclear-powered submarines, in close communication with the United States.

This language appears to leave open the possibility of acquiring low-enriched uranium from the United States or developing an indigenous enrichment program, potentially also in cooperation with the United States. The two states concluded a cooperation agreement in November 2025 and further discussed potential cooperation on enrichment and reprocessing technologies in January 2026.

On 21 May 2026, the US Nuclear Regulatory Commission accepted a license application of Orano Enrichment USA, a subsidiary of the French company Orano, for a new enrichment facility, named Project Ike, in Oak Ridge, TN.

The NRC committed to consider the application on an accelerated schedule, with the goal of completing the process in April 2027. According to the NRC, this is possible in part because of similarities with "the previously approved Eagle Rock Enrichment Facility (EREF)." Orano's predecessor, Areva, announced a plan to build the EREF facility in Bonneville County, ID, in 2008. However, Areva suspended the project in 2011, and in 2018 Orano asked NRC to terminate the license.

According to an industry report, the license states that the Project Ike plant will have a capacity of 7,400 tSWU/y and will be capable of enriching uranium to 10% U-235. The plant will use ETC centrifuges, which the company uses at its facilities in France.

Orano announced its intent to build a new enrichment plant in the US in September 2024.