IPFM Blog

France can use its existing stock of fissile materials to produce new nuclear warheads

2026-03-04T21:24:45Z

France's minister of the armed forces, Catherine Vautrin, said in an interview for Le Dauphiné Libéré that France can use the uranium and plutonium extracted from warheads dismantled after the end of the Cold War to support the increase of the French nuclear arsenal, announced by President Macron in his address on 2 March 2026. Catherine Vautrin was quoted as saying that:

Nous avons conservé les matières fissiles (uranium et plutonium) issues des têtes nucléaires démantelées après la guerre froide. À ce titre, nous disposons d'un stock totalement suffisant pour produire les nouvelles têtes nucléaires annoncées par Emmanuel Macron. Concernant le tritium qui, lui, ne peut pas être recyclé, le président a lancé un programme national dédié pour assurer notre approvisionnement.

The translation of the quote is below:

We have retained the fissile materials (uranium and plutonium) from the nuclear warheads dismantled after the Cold War. In this regard, we have a fully sufficient stockpile to produce the new nuclear warheads announced by Emmanuel Macron. As for tritium, which cannot be recycled, the President has launched a dedicated national programme to ensure our supply.

France is estimated to have about 6 tonnes of plutonium and about 25 tonnes of HEU that are available for weapons. These amounts far exceed what is required to maintain France's current arsenal of fewer than 300 warheads.

The size of the post-Cold War arsenal was first officially disclosed in 2008. In his address on 21 March 2008 in Cherbourg, then President of France Nicolas Sarkozy stated that

our arsenal will include fewer than 300 nuclear warheads. That is half of the maximum number of warheads we had during the Cold War.

The 300-warheads ceiling was then confirmed by President Hollande in 2015 and President Macron in 2020.

The 2008 announcement suggests that France can at least double the number of nuclear warheads in its arsenal, going back to the Cold War levels. It also appears to have enough material for a more significant increase. While the exact amounts of uranium and plutonium in French warheads are unknown, it may be estimated that 300 warheads contain about 1.2 tonnes of plutonium and about 5 tonnes of HEU out of 6 tonnes and 25 tonnes of the stock available for weapons respectively.

Unlike uranium and plutonium, the stock of tritium produced during the Cold War requires replenishment. In March 2024, France unveiled a program to produce tritium in the EDF civilian reactor in Civaux. In the past, tritium was produced in reactors of the CEA (Commissariat à l'Energie Atomique, Atomic Energy Commission).

2024 civilian plutonium and HEU declarations submitted to IAEA

2026-03-02T17:23:57Z

This post contains a summary of INFCIRC/549 reports by the countries that submit annual civilian plutonium declarations that reflect the status of civilian plutonium stocks as of 31 December 2024. The total amount of plutonium declared as civilian was about 379 tonnes, an increase of about 5 tonnes since the end of 2023. Only about 146 tonnes of this material are under international (IAEA or Euratom) safeguards. The other 232 tonnes are not safeguarded, but are covered by various obligations not to use the material for military purposes.

Japan (INFCIRC/549/Add.1-28) reported owning the total of 44.4 tonnes of plutonium, 8.6 tonnes of which is in Japan (the numbers in 2023 were 44.5 tons and 8.7 tons respectively). According to the Status Report on Plutonium Management in Japan - 2024 released in August 2025, out of the 35.8 tons of plutonium abroad, 21.713 tonnes are in the United Kingdom and 14.079 tonnes are in France.

Germany (INFCIRC/549/Add.2-28) reported having no separated plutonium in the country for the fifth year in a row. Germany does not report separated plutonium outside of the country. It is believed to be less than 1 tonne.

Belgium (INFCIRC/549/Add.3-24) declared no separated plutonium in storage or at reprocessing plants and "not zero, but less than 50 kg" of separated plutonium in other categories. It reported that it had no foreign plutonium as of 31 December 2024.

Switzerland (INFCIRC/549/Add.4-29) reported having less than 2 kg of plutonium in the country (in the "located elsewhere" category). The number has not changed since 2016 (it was "less than 50 kg" in 2015).

France (INFCIRC/549/Add.5-29) reported having 113.7 tonnes of separated unirradiated plutonium in its custody. Of this amount, 14.45 tonnes belongs to foreign countries (no change since 2023). Almost all that plutonium - 14,079 kg - belongs to Japan. The amount of plutonium owned by France is 99.25 tonnes, an increase of 3 tonnes from previous year (96.25 tonnes).

The United States (INFCIRC/549/Add.6-26) declared 49.4 tonnes of separated plutonium, of which 4.6 tons are in MOX fuel and 44.8 tons are "held elsewhere" (most of this material is believed to be in weapon components). The total amount was reported to be 49 tons in 2023. Note that the United States did not submit the 2023 report. The 2024 report, however, contains some data that refer to the 2023 amounts. The amount described as "disposed as waste" was 5.3 tonnes in 2024, an increase from 4.7 tonnes in 2022.

China has not has not submitted its 2017-2024 reports as of 2 March 2026. The last INFCIRC/549 report submitted to the IAEA showed 40.9 kg of separated plutonium as of 31 December 2016.

The United Kingdom (INFCIRC/549/Add.8-28) reported owning 116.8 tonnes of separated plutonium (no change from 2023). In addition to that, the United Kingdom stores 24.1 tonnes of foreign plutonium (of which 21.713 tonnes is owned by Japan and 1.58 tonnes by Italy). The total amount of separated plutonium in the United Kingdom is 140.9 tonnes.

Russia (INFCIRC/549/Add.9-27) reported owning 66.1 tonnes of civilian plutonium, an increase from 64.9 tonnes reported in 2023.

In addition to reporting plutonium stocks, some countries also submit data on their civilian HEU:

Germany reported 0.42 tonnes of HEU in research reactor fuel (0.39 tonnes in 2023), 0.94 tonnes of HEU in irradiated research reactor fuel, and 0.02 tonnes in the category "HEU held elsewhere."

France declared 5363 kg of HEU (5369 kg in 2023), of which 3749 kg (3801 kg) is unirradiated material - 539 kg (573 kg) of HEU at fuel fabrication or reprocessing plants, 10 kg (51 kg) at civil reactor sites, 3200 kg (3177 kg) at various research facilities. Also declared are 1614 kg (1551 kg) of irradiated HEU - 52 kg (40 kg) at civil reactor sites and 1562 kg (1528 kg) in other locations.

The United Kingdom reported having 637 kg of HEU (636 kg in 2023). Of this amount, 501 kg is unirradiated HEU (499 in 2023): less than 1 kg of unirradiated HEU is stored at the enrichment plants, less than 1 kg is at civil reactor sites, 438 kg - at fuel fabrication facilities, and 63 kg - at other sites (412 kg and 87 kg respectively in 2023). Irradiated HEU is located at civil reactor sites (5 kg) and other sites (132 kg).

New provisional operation plan for Rokkasho

2026-01-29T00:18:35Z

On 28 January 2026, Japan Nuclear Fuel Limited (JNFL) published a provisional five-year operation plan for the Rokkasho Reprocessing Plant and the MOX Fuel Fabrication Plant. The document confirms the previous plan, published in December 2024, which followed the announcement of a delay in bringing the Rokkasho plant into operation made in August 2024.

The current plan assumes that the plant will extract its first 0.6 MT of plutonium by reprocessing 70 MT of fuel in the second half of FY2027. The plant is expected to reach the capacity of 400 MT of fuel a year (3.2 MT of plutonium) in FY2030.

The MOX fuel fabrication plant is projected to produce the first fuel (containing 2.0 MT of plutonium), in FY2030.

Two companies expand centrifuge development centers at Oak Ridge

2026-01-26T22:43:30Z

On 26 January 2026, two companies announced plans to expand centrifuge manufacturing facilities in Oak Ridge, TN. BWXT opened its Centrifuge Manufacturing Development Facility. Another company, Centrus, announced the plan to expand the Technology and Manufacturing Center.

For BWXT, the facility is part of the plan to establish the supply of unobligated domestic enriched uranium. The company received a $1.5 billion contract from NNSA in September 2025.

The Centrus expansion is supported by funds provided by the Department of Energy earlier in January 2026.

US Department of Energy selects companies to expand domestic enrichment capacity

2026-01-05T20:24:04Z

US Department of Energy awarded $2.7 billion to three companies "to provide enrichment services for LEU and HALEU:

American Centrifuge Operating ($900 million) to create domestic HALEU enrichment capacity
General Matter ($900 million) to create domestic HALEU enrichment capacity
Orano Federal Services ($900 million) to expand U.S. domestic LEU enrichment capacity."

General Matter and Centrus/American Centrifuge Operating were among the four companies selected in 2024 to build domestic HALEU supply. In August 2025, General Matter leased a plot of land in Paducah with the intent to "reindustrialize the former Paducah Gaseous Diffusion Plant." The company has yet to operate an enrichment facility or, indeed, to unveil the technology it intends to use.

Centrus produced its first 900 kg of HALEU in 2025 and plans to expand the production capacity.

Orano received the award to build an enrichment facility in Oak Ridge, Tennessee. The company estimated the total cost of this project "at nearly $5 billion."

The $2.7 billion award is part of the program to boost US domestic enrichment capacity announced in June 2024.

Small HEU shipment licensed for South Korea's Kijang reactor

2025-12-18T19:30:33Z

On 18 December 2025, the US Nuclear Regulatory Commission issued a license XSNM3854, which allows Mirion Technologies, a US company, to export "0.00462 kg of HEU, enriched to up to 93%, containing 0.00432 kg of uranium-235." The material is contained in six assemblies that will be used for monitoring of thermal neutron flux radiation in Kijang research reactor.

Framatome successfully tested LEU fuel for FRM-II reactor

2025-12-18T16:21:27Z

The French company Framatome, which is producing LEU fuel for the FRM-II reactor at the Technical University of Munich, successfully completed irradiation tests of the fuel. According to TUM, "two fuel plates made of a monolithic uranium-molybdenum alloy" were irradiated during two cycles in the BR-2 reactor at the Belgian research centre SCK CEN in Mol.

A step toward the disposition of UK civilian plutonium

2025-12-18T15:43:35Z

The United Kingdom's Nuclear Decommissioning Authority (NDA) has successfully converted "a can of plutonium residue" into a stable waste form suitable for disposition. This step is part of the program that aims to process "around 400 cans of plutonium residue" stored at the NDA group's Sellafield site. According to the Sellafield CEO, this particular step means that the UK is able to "deal with some of the more problematic plutonium."

The United Kingdom has the largest stock of civilian plutonium, 116.8 tonnes as of the end of 2023 (in addition, there is 21.7 tonnes of Japan's plutonium stored in the UK). In January 2025, the UK government made a decision to immobilize UK-owned plutonium. In August 2025, the government allocated £154 million toward this program.

The United Kingdom is reportedly exploring two immobilization options - Disposal MOX and Hot Isostatic Pressing. Both processes create ceramic material suitable for disposal.

For a discussion of the storage MOX option, see this article:

J. Kang, F. N. von Hippel, A. Macfarlane, R. Nelson, "Storage MOX: A Third Way for Plutonium Disposal?," Science & Global Security, 10, no. 2, (2002): 85-101.

Rosatom begins deployment of new-generation centrifuges at Seversk

2025-12-02T07:48:06Z

The Siberian Chemical Combine in Seversk became the third Russian enrichment plant that began deployment of centrifuges of the 9+ generation. The program is expected to be completed in 2027.

The first enrichment plant to undergo modernization was the Electrochemical Plant in Zelenogorsk (the installation of new centrifuges began in 2019 and was completed in 2025). The installation of generation 9+ centrifuges at the Urals Electrochemical Combine in Novouralsk began in 2018. According to the TVEL report, the generation 9+ centrifuges will be installed at the Angarsk Electrolysis Chemical Combine as well.

Russia is also working on what was described as 10th-generation centrifuges.

United States pledges support for enrichment, reprocessing, and naval reactors in South Korea

2025-11-13T09:18:39Z

According to the fact sheet released by the White House, at the 29 October 2025 summit meeting the presidents of the United States and the Republic of Korea reached an agreement that will support the development of nuclear fuel cycle technologies as well as that of naval nuclear reactors in South Korea.

The fact sheet states:

Consistent with the bilateral 123 agreement and subject to U.S. legal requirements, the United States supports the process that will lead to the ROK's civil uranium enrichment and spent fuel reprocessing for peaceful uses.
The United States has given approval for the ROK to build nuclear-powered attack submarines. The United States will work closely with the ROK to advance requirements for this shipbuilding project, including avenues to source fuel.

The 123 agreement between the United States and the Republic of Korea, concluded in 2015 and expected to remain in force until 2040, does not prohibit the development of enrichment or reprocessing. However, it imposes restrictions on the use of materials or technologies supplied by the United States under this cooperation agreement.

The clause that deals with nuclear-powered submarines does not seem to commit the United States to a transfer of technology or material. Importantly, the current agreement explicitly prohibits enriching US-origin uranium to more than 20% uranium-235.

Russia withdraws from the Plutonium Management and Disposition Agreement

2025-10-27T20:59:23Z

The President of Russia signed a federal law that formally ended Russia's participation in the US-Russian Plutonium Management and Disposition Agreement (PMDA). The law denounces the agreement, signed on 29 August 2000 in Moscow and on 1 September 2000 in Washington, and the protocols to the agreement, signed on 15 September 2006 and on 13 April 2010.

The agreement, as amended by a protocol in 2010, committed the United States and Russia each to eliminate 34 tonnes of plutonium "designated as no longer required for defense purposes."

Russia suspended the implementation of the agreement in October 2016, citing "unfriendly actions of the United States." To a large extent the suspension was a result of a dispute about the United States unilaterally changing its plutonium disposition method (see also earlier IPFM analysis as well as this article).

It is worth noting that while Russia ratified PMDA in 2011, the agreement has never been in force. The Federal Law No. 108-FZ on the ratification of PMDA was signed by the then-President Medvedev on 3 June 2011. The law would have entered into force ten days after its official publication on the pravo.gov.ru portal. However, it has never been officially published and therefore the agreement has never entered into force. For this reason, the current law denounces the agreement and its protocols directly rather than denouncing the 2011 law that ratified it.

In 2016, Russia's participation in the PMDA was suspended by a presidential decree (which also did not mention the fact of ratification in 2011). In it, President Putin decreed:

To establish that plutonium covered by the [PMDA] Agreement [...] shall not be used for the purposes of manufacturing nuclear weapons or other nuclear explosive devices, for research, development, design, or testing related to such devices, or for any other military purposes.

The legal status of this obligation is not clear but it appears to remain in force unless a subsequent presidential decree revokes it. The Federal Law No. 381-FZ from 31 October 2016, which was passed to codify the suspension, does not contain this clause. The law on the denunciation of PMDA does not revoke or even mention the 2016 decree, so it appears that the obligation not to use the PMDA material for military purposes continues to apply.

US Department of Energy makes plutonium available to industry

2025-10-21T10:57:15Z

On 21 October 2025, the US Department of Energy issued a Request for Applications DE-FOA-0003594 as part of "a program for making surplus plutonium materials available to industry for advanced nuclear technologies."

The program was established by the May 2025 executive order that also terminated the previously selected disposition route, the dilute and dispose program. That program was authorized in 2016 and sent the first material to WIPP in 2022. It should be noted that the DoE does not exclude the possibility of returning some of the material allocated to the current program to the dilute and dispose route.

The total amount of plutonium that is offered to industry is 19.7 metric tons (MT). Of this, 15.3 MT is in oxide form and 4.4 MT is in the metal form. About 7.1 MT of this is weapon-grade plutonium (about 1 MT is in metal form). The full breakdown by categories is in the table below. An earlier report by Politico suggested that the DoE is prepared to make available up to 25 MT of plutonium.

According to ANS, there are at least four companies that expressed interest in using plutonium: Curio, Lightbridge, Newcleo, and Oklo.

Enrichment plant in Rokkasho prepares to resume operations

2025-10-14T15:44:34Z

The uranium enrichment plant in Rokkasho, operated by Japan Nuclear Fuel Ltd, has received a shipment of natural uranium from Cameco, a Canadian company. The shipment included "up to 625 tons of uranium contained in 50 cylinders" (50 48Y cylinders).

This is the first shipment of uranium to Rokkasho since July 2014. As shown in the chart, reproduced from the JNFL site, the plant has shipped virtually no enriched uranium after 2012.

It is not clear if the plant has been producing enriched uranium during this period. According to an industry report, the plant suspended operations in 2017, but resumed them in August 2023.

It was estimated that in 2019, the plant had the capacity of 75 tSWU/year. The current capacity of the plant is reported to be 112.5 tSWU/year. The same report says that JNFL aims to expand capacity to 450 tons SWU/year by FY2028. This plan appears to include the upgrade of the No. 2 cascade facility with the capacity of 150 tSWU/year.

The JNFL plans to eventually bring the capacity of the plant to 1,500 tSWU/year.

BWXT receives contract to build a pilot enrichment facility

2025-09-16T12:07:02Z

US National Nuclear Security Administration (NNSA) awarded a contract, currently valued at $1.5 billion, to BWXT Enrichment Operations, LLC "for the licensing, manufacturing development, facility construction, and operations of a Domestic Uranium Enrichment Centrifuge Experiment (DUECE) pilot plant."

The plant is part of the effort to establish the supply of unobligated enriched uranium that can be used for defense purposes: LEU for tritium production and HEU for naval nuclear propulsion.

In 2024, NNSA asked Nuclear Fuel Services, a subsidiary of BWXT, to conduct a study of domestic enrichment options.

The 9th MOX fuel shipment to Japan

2025-09-06T09:03:25Z

According to Orano, the 9th shipment of MOX fuel from France to Japan has left France on 6 September 2025 and is expected to arrive in Japan in November 2025. The ships that transfer the fuel are "Pacific Heron and Pacific Egret, the specialized ships belonging to British company PNTL."

The 8th shipment was completed in September 2022.

UPDATE: The ships arrived in Japan on 17 November 2025.