Posted on: 10th June 2015

Experiments with tritium are rare events which spark curiosity amongst the fusion community both in Europe and beyond. The Culham Centre for Fusion Energy, home to JET, has just received the first batch of tritium as part of preparations for the next set of full tritium experiments scheduled in 2017/2018.

Since 2011, JET has been using beryllium and tungsten as plasma-facing materials in the vessel. As the name suggests JET’s ITER-like wall is constructed using the same materials that will be used in ITER, the next generation fusion experiment which is currently being built in France.

So far, experiments with the new wall have been fuelled by hydrogen and deuterium. Since the most economic fuel for future fusion power plants is a mix of deuterium and tritium, this mixture needs to be put to the test.

picture of the virtual vessel

This view inside the JET vessel is a blend of computerised imagery and photography.

As part of the preparations for this extraordinary event, the first delivery of tritium has arrived at the Culham Centre for Fusion Energy (CCFE), the home of JET. Tim Jones, project sponsor from CCFE explains: ‘For licensing reasons, only a limited amount of tritium may be transferred over the JET tritium storage facility in an individual batch quantity. Additional batches will later be delivered in order to collect together a total amount of 55 grams that will be needed for the scheduled campaign”.

Dedicated sets of experiments using deuterium and tritium are necessary to promote understanding of the influence of the fuel isotope on plasma performance and on interactions between the plasma and the new wall.

Similar experiments to those planned with tritium are being prepared with hydrogen and deuterium, so far the results show that ITER operating regimes are compatible with the new wall materials.

Lorne Horton, Head of the JET Exploitation Unit explains ‘We are now exploring the performance limits of deuterium plasmas. The goal of the deuterium-tritium experiments is to prove that our findings can be applied to the fuel mixture that will be used in a fusion reactor’, and he adds: ‘The results of the tritium experiments are invaluable for ITER which must demonstrate the feasibility of fusion as an energy source’.

JET auxiliary systems are also being upgraded to enable sustained tritium operation and, just as importantly, operating staff are being trained to safely work with the radioactive material and to confidently operate JET and its sub-systems with the fuel.

At this point in time, JET will be closing down in 2018. EUROfusion Programme Manager, Tony Donné, has suggested continuing with JET operation into 2020: ‘An extended schedule is scientifically sensible and this concept is supported by many in the fusion community. It would allow us more time to prepare the experiments and exploit the ITER-like wall more intensively.’ He continues, ‘We hope to receive a decision from our stakeholders this year which will enable us to adjust the schedule accordingly.’

JET’s next tritium experiments materialise: An Update: 23/07/15

The Joint European Torus (JET), Europe’s flagship research facility is preparing for another high-power deuterium tritium (DT) campaign, the first since 1997, when 16 megawatts of fusion power were produced. This, as mentioned in the article, has sparked excitement in the fusion community. At present, JET experiments are scheduled to end in 2018, and this might mean not meeting the complete objectives of the DT campaign at JET. To ensure that the campaign can accomplish its full objectives, EUROfusion has approached the European Commission about an extension of JET by two years. The request is backed by the results of a working group, led by Prof. R. J. Hawryluk of Princeton Plasma Physics Laboratory (USA).

Following the presentation of the working group’s report at the July 2015 EUROfusion General Assembly, the highest decisive body in the EUROfusion consortium, the EUROfusion members unanimously endorsed the suggested extension until 2020. “An extended schedule would allow us additional time to prepare the experiments and exploit the ITER-like wall more intensively. We hope to receive an in principle agreement from the European Commission after summer, which will enable us to adjust the schedule accordingly, even though we are aware that the formal decision on the EUROfusion programme beyond 2018 can only be taken in the course of 2017”, says Tony Donné, EUROfusion Programme Manager.

Stay tuned to read about the developments on this front.

 

Background

EUROfusion, the ‘European Consortium for the Development of Fusion Energy’, manages and funds European fusion research activities on behalf of Euratom.

The signatories of the EUROfusion consortium agreement are 26 member states* of the European Union plus Switzerland as associated member. They signed the agreement on behalf of about 40 fusion laboratories which are themselves linked to more than 100 third parties.

EUROfusion funds fusion research activities in accordance with the roadmap to the realisation of fusion energy. The roadmap outlines the most efficient way to realise fusion electricity by 2050.

Decisions such as changed schedules for JET are taken by the highest body in EUROfusion, the General Assembly, the European Comission and the UK Government.

*Austria, Belgium, Bulgaria, Croatia, Cyprus, Czech Republic, Denmark, Estonia, Finland, France, Germany, Greece, Hungary, Ireland, Italy, Latvia, Lithuania, Poland, Portugal, Romania, Slovakia, Slovenia, Spain, Sweden, Switzerland, The Netherlands and United Kingdom.

The JET facilities are operated in accordance with the European fusion roadmap by way of a contract between the European Commission and the Culham Centre for Fusion Energy (CCFE).

The JET Exploitation Unit coordinates the interaction between the operator, the Culham Centre for Fusion Energy (CCFE) and EUROfusion, ensuring that the facilities are ready for the realisation of the experimental programme.

ITER will be the first magnetic confinement device to produce a net surplus of fusion energy and will also demonstrate the main technologies for a fusion power plant. ITER is currently being built in southern France within the framework of a collaboration between China, Europe, India, Japan, Korea, Russia and the USA.