Petition to extend JET beyond 2023

Contact the author of the petition

Reply of Tony Donné and Ambrogio Fasoli, EUROfusion, to letter from petition representatives. Received 03/11/2023.

2023-11-07 12:48:00

Dear Dr. Hotchin, Dr. Solano, Dr. Sharapov, Dr. Lennholm, and Dr. Ongena,

Thank you for your email dated November 2, 2023, and for sharing the petition regarding the Joint European Torus (JET) facilities. We have carefully reviewed your letter and the voices of the 800+ fusion professionals advocating for the extension and upgrading of JET.

At EUROfusion, we deeply respect the passion and dedication to fusion research that these appeals represent. The Joint European Torus has indeed been instrumental in advancing our collective understanding and bringing us closer to the realization of sustainable fusion energy.

Given the current discourse on the future of JET, we believe it is important to share EUROfusion's positioning statement. This encapsulates our perspective, informed by extensive deliberations and assessments of the broader context of fusion research and the evolving needs of our scientific community. -----------------------------------------------------------------------------------------------------------------------------

EUROfusion's Positioning Statement on the Future of the Joint European Torus (JET)

In the dynamic and evolving landscape of fusion research, EUROfusion has consistently championed the pursuit of scientific advancement and international collaboration. The Joint European Torus (JET) has been a cornerstone of European fusion research, contributing invaluable insights and propelling the global community closer to the realization of sustainable fusion energy.

In 2016, recognizing the potential benefits of extending JET’s operational life in support of ITER, EUROfusion proposed an internationalization that would have secured its future. Regrettably, this proposal did not garner the necessary support of the international community at the time. Now, as we stand at a crossroads, we acknowledge the voices calling for JET's continued operation and deeply respect the passion and dedication to fusion research that these appeals represent.

However, we must also confront the present realities. Not only has the landscape of fusion research shifted significantly, but JET itself would require substantial investment for upgrades to continue operations—a process that would take years to complete. During this time, the facility would remain non-operational, delaying further research and advancements. Furthermore, the UKAEA has already initiated the decommissioning process of JET and reassigned its many researchers, technicians, and staff.

Given these factors, and our budgetary constraints, we must consider the broader portfolio of research facilities that also warrant support. With a future-oriented mindset, we need to look towards the future, not back to the past. This perspective is not a dismissal of JET's monumental contributions but an acknowledgment that the path to fusion energy requires us to adapt, innovate, and sometimes make difficult decisions.

Our focus now turns to ensuring that the legacy of JET is preserved. We are committed to safeguarding the wealth of knowledge and data accumulated, facilitating a seamless transition for the talented JET team, and continuing to drive fusion research forward through our existing and future initiatives.

EUROfusion remains steadfast in its mission to realise sustainable fusion energy. We are dedicated to fostering collaboration, supporting cutting-edge research, and advocating for policies that advance the fusion field. Together with our partners, we look to a future illuminated by the promise of fusion energy. -----------------------------------------------------------------------------------------------------------------------------

We understand that our perspective may not align with the desires expressed in the petition. However, please rest assured that our commitment to advancing fusion energy research and fostering international collaboration remains unwavering. We are dedicated to ensuring that the legacy of JET is preserved, and the expertise of its talented team is effectively integrated into future projects.

We are open to any further discussions or clarifications you might seek on this matter. Your insights and contributions to fusion research are invaluable, and we are committed to maintaining an open and constructive dialogue as we navigate this evolving landscape together.

Thank you once again for your dedication to the field of fusion energy and for initiating this important conversation.

Warm regards,    

Tony Donné – Programme Manager (CEO) EUROfusion and Ambrogio Fasoli – Chair and Programme Manager Elect of EUROfusion    


Update: dialog with UKAEA and EUROfusion. Includes message from Sir Ian Chapman, UKAEA CEO.

2023-11-06 15:20:20

Dear fusion leaders and authorities

We have now received a reply from Sir Ian Chapman, CEO of UKAEA. I attach it below. We have posted and re-sent the reply from Tony Donné, EUROfusion Leader, earlier, see Annoucement #3 on the petition web site .

From the point of view of this petition I would highlight Ian's statement "We are always open to potential collaborations, and if another partner brings forward a scientifically meritorious proposal with full finance, then we would discuss this, but we would need to receive such proposals very soon. "

We are grateful to Ian for opening up this opportunity. We note that also the letter from Tony Donné invites insights and contributions from the community. If any international fusion groups think there is merit to the proposal described in the petition, please inform Ian as soon as possible. Please keep us in copy.

For the time being we would like to separate the assessment of merit of the proposal from funding issues. We propose to install a W wall and gyrotrons at JET, and keep it alive for another ~10 years. We ask fusion leaders to inform Ian and ourselves of their views on this. Note the manty comments from petition subscribers: all support the proposal (894 signatures at the moment).

Ian is correct, we are describing a project likely to cost ~€100M/year for 10 years, although it can start with less. Gyrotrons, a W wall and dedicated personnel cost money.

Synergies with the UK and EUROfusion programmes may allow some funding from them, despite past decisions. But internationalization of JET may be key to unlock negotiations. And if private partners are interested, this could also prove to be very helpful.

First, let us agree on what would be desirable, beyond the present plans of UKAEA and EUROfusion.

Regards the JET petition team, jet dot petition dot 2023 at gmail dot com


From: Chapman, Ian T <>

Sent: Friday, November 3, 2023 3:02 PM

Subject: RE: Letter to Fusion Authorities, JET petition

Dear all

Thank you for your email and the passion that you clearly share for delivering fusion.

JET is a remarkable facility that has achieved remarkable things and demonstrated the benefit of many partners working together. Fusion would not be at the stage it is today without JET. ITER would not be happening, so many discoveries would not have been made, a generation of fusion experts would not have been trained and we would not have confidence to be moving forward with designs for fusion powerplants. JET has already operated for decades longer than originally anticipated due to the ingenuity and prescience of the team.

However, at the same time, we must plan for the future of fusion. Extending JET operations without upgrades would lead to only incremental science and therefore is not worth the substantial annual running costs of the facility. Enacting upgrades such as the ones you describe, whilst scientifically valuable, would take of order ten years to design, build, commission and then scientifically exploit. This would cost of order £1Bn as well as leading to greater decommissioning liability. These are costs that will not be borne by the UK government. The UK government’s fusion strategy is clear that we plan for decommissioning and repurposing of JET whilst at the same time substantially investing in the fusion sector through many new research facilities, a prototype powerplant programme and growth in the fusion industry. Cessation of JET operations is not a cause for despondency, but a transition towards an exciting future with many new facilities, research programmes and a clear mission to deliver fusion power.

In line with the government’s published fusion strategy (Towards Fusion Energy 2023: The next stage of the UK’s fusion energy strategy (, UKAEA will begin the decommissioning and repurposing of JET from 1st January 2024. We have already discussed extension of JET operations at length with our EUROfusion partners who agree that it is time to plan for a future without JET. Indeed, eight years ago we discussed major upgrades to JET with the international community, exactly as you propose, but at the time when decisions for major upgrades needed to be taken. Unfortunately, we could not secure agreement for enhancements with the international community and so it was eventually decided at the EUROfusion General Assembly (with the UK in agreement) to plan for the end of scientific operations in 2023. We are always open to potential collaborations, and if another partner brings forward a scientifically meritorious proposal with full finance, then we would discuss this, but we would need to receive such proposals very soon. In the meantime, we are focussed on planning for decommissioning, itself an exciting programme essential for the future of fusion, and as such we do not have any spare resource to work on alternative plans.

Regards Ian


Prof Sir Ian Chapman FRS FREng FInstP HonFNucl

Chief Executive Officer United Kingdom Atomic Energy Authority


JET petition in Physics World

2023-11-04 08:12:22


Letter to Fusion authorities, 2nd November 2023

2023-11-02 14:28:14

Esteemed international fusion leaders:

We write to you representing the fusion professionals that have signed the petition to enable the use of JET facilities for DT operations well beyond 2023, petition_to_extend_jet. The petition was launched on October 16th 2023, after the ITER talk at IAEA FEC describing ITER’s new plans: a tungsten wall and dominant electron cyclotron heating.  Such a dramatic ITER move changes the timeline of magnetic fusion significantly. The closure of JET in 2023 seems now premature as it would result in a skills’ shortage, and technological and scientific gaps: no equivalent fusion DT plant will be available for many years to come. Rather than closing JET at the end of 2023 and decommissioning it from 2024 (as presently planned by UKAEA), we propose the installation of a tungsten wall in JET and an ECRH system in JET,  as an international collaboration.

The signatories' comments emphasize that JET is one of the most valuable assets in present day fusion, largely from its irreplaceable DT capabilities. The fusion world would benefit from using the existing JET infrastructure and facilities as an international fusion facility, with DT capabilities, a W wall and ECRH. This would provide relevant and timely experimental data from a large machine and a testbed for technology, in support of ITER and future fusion reactors anywhere in the world.

The petition has been signed by more than 800 fusion professionals in less than 3 weeks. We would highlight signatures from Paul-Henri Rebut, who built JET, Osamu Motojima, former Director of the ITER Organisation, and Jerome Pamela, former JET and EFDA Leader, amongst many others.

In consequence, representing the signatories, we address this letter to the relevant fusion authorities, with the following requests:

1.    We ask the UK, the EU and the ITER Organization to evaluate the benefits of upgrading and operating JET.

2.    We ask the UKAEA, current owner of the JET Facilities, to invite expressions of interest from the international fusion community.

3.    We ask the international fusion community, including the ITER partners, private companies and industry, to proactively inform the UK and the EU of their interest in joining such an endeavour, specifying what they might contribute: expertise, hardware, funding. Please send such expressions of interest and proposals to the CEO of UKAEA, Sir Ian Chapman, and to the EUROfusion Programme Managers Dr. Tony Donne (2023) and Dr. Ambrogio Fasoli (from 2024), adding authorities you find appropriate in copy. We would be grateful if a copy of such expressions of interest could be sent to jet.petition.2023 at gmail dot com

Yours sincerely,

Simon Hotchin, Tokamak Operations Manager, UK

Emilia R. Solano, JET scientist, Madrid, Spain

Sergei Sharapov, JET scientist, UK

Morten Lennholm, Senior Plasma Control Expert, STEP, UK

Jef Ongena, JET scientist, Brussels, Belgium

representing the signatories of the petition, all of whom signed as individual fusion professionals, not representing the views of any institution.

Attachments: Excel with signatures up to noon 2 Nov 2023, PDF with Letter and Recipient list.

Additional information can be found in the petition web page, https://www.petitions. net/petition_to_extend_jet




DG: Rafael Grossi 

Senior Advisor to DG: Diego Candano-Laris  



CEO: Sir Ian Chapman              

Board Chair: Lady Eithne Birt

Deputy CEO: Tim Bestwick


CEO:  P. Methven

Board Chair: David Gann



Director: Pietro Barabaschi

ITER Domestic agencies: please forward to suitable contacts within the countries you represent, if not already listed.

Chinese Domestic Agency: T Fang      

European Domestic Agency F4E

Director: Marc Lachaise

Board Chair:  Carlos Alejaldre


Project Director: Ujjwal Baruah

ITER Japan Domestic Agency:

              Head: M. Sujimoto

Deputy Head: T Inoue

ITER Korea:

Head: HG Lee

ITER-Russia Domestic Agency

Head Anatoli Krasilnikov

US ITER Project

Director: Kathy A McCarthy



Programme Manager (2023):  Tony Donné

Programme Manager (from 2024): Ambrogio Fasoli

EUROFUSION Heads of Research Units, added in bcc.

European Commission:

EURATOM Research Head: Elena Righi-Steele

DG ENER Commissioner: Kadri Simson

DG ENER DG : Juul-Joergens

DG ENER Deputy DG:  Massimo Garriba

DG RTD Commissioner: Iliana Ivanova 

DG RTD Director General: Marc Lemaitre         


USA contacts, DOE:

Associate Director Office of Science, Fusion Energy Sciences: JP Allain

Senior Advisor and Lead Fusion Coordinator: Scott C. Hsu


JET petition press release

2023-10-20 15:52:56
Fusion researchers from all over the world call on the UKAEA to invite the international fusion community to find a way to suitably upgrade JET and continue operations.

The UK and the world fusion programmes, including STEP and ITER, would greatly benefit from JET renewal: it would help maintain know-how and provide training opportunities for the next generation of fusion experts in the largest magnetic confinement fusion experiment in the world.

More than 500 experts have signed the petition in the last five days. P-H. Rebut, who built JET, is amongst the most notable supporters. Many of the signatories are attending the IAEA Fusion Energy Conference in the Queen Elizabeth Centre in London. It will close tomorrow at 5 pm.


Group photo this noon 12:30

2023-10-20 05:26:24

Dear supporters of the JET petition:

thank you very much for signing in such numbers. In 4 days we got more than 450 signatures! Not bad. But we need more to strengthen further our case. Do encourage your colleagues to sign this week, please.

For those of us who are at IAEA FEC, we propose to get together for a group photo tomorrow Friday at 12:30. We will meet at the ground floor of the Queen Elisabeth Convention Centre, near the door, on the side away from the cafe. If it's not raining we can move outside.

It would be wonderful if we could get a large enough group.

Beware we might release the photo to the media. 

We hope you'll join us!

See you tomorrow!




Group photo

2023-10-19 21:21:41

Dear supporters of the JET petition:

thank you very much for signing in such numbers. In 4 days we got more than 400 signatures! Not bad. But we want more. Do encourage your colleagues to sign this week, please.

For those of us who are at IAEA FEC, shall we get together for a group photo tomorrow Friday at 12:30? we propose we meet at the ground floor of the Queen Elisabeth Convention Centre, near the door, on the side away from the cafe. If it's not raining we can move outside.

It would be wonderful if we could get a large enough group.

Beware we might release the photo to the media. 

We hope you'll join us!

See you tomorrow!


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