Why the US Should Join ITER - A European's Perspective

by Dr. Richard J. Buttery, UK
richard.butteryukaea.org.uk

20 March 2002

Disclaimer: These opinions represent the personal views of the author, and not necessarily the position of the European Union or other organisations.

Summary: A power plant scale experiment is a vital step in the route towards fusion power. ITER is the machine that addresses this need - now is the crucial time to ensure it goes ahead. Getting on board with ITER provides the US with a vital opportunity to play a leading role in an exciting programme to take fusion to the power plant stage. In contrast, a US rejection of ITER would send a very negative message to fusion programmes, and their funding bodies, world-wide. This could set back ITER and the timescale to fusion power. Once ITER is secured, we should then look at strategies to provide "complementary facilities", which might aid the development of fusion technology and reduce the timescale to fusion power. I urge my American colleagues to work with the rest of the community, to ensure a world programme that is strong enough, and diverse enough, to address all of the issues, speeding progress to a fusion power plant.

The European fusion programme is increasingly centred on ITER. ITER-relevance is at the heart of the strategy for development of new and existing facilities, and plays a central role in formulating physics programmes. Such a focus is supported by an unprecedented consensus among the European fusion community (for example a recent letter to the European Commission in support of ITER had 1767 co-signatories from the fusion community). However, the funding of the EU programme has now reached a critical stage, with key questions pertaining to how much of the existing funds should be re-allocated directly into ITER activities, and whether additional funds, and a site, should be made available for construction of ITER.

As was highlighted at the recent APS meeting, the fusion community is now ready for a next step in plasma physics, with fundamental progress having been made on a wide range of fronts - from stability and transport barrier control to baseline performance and real fusion demonstrations. Further progress can still be made with present devices, developing new techniques, proving technologies, and further resolving physics issues. However many of the basic approaches for obtaining high performing regimes are now established. To move significantly further in developing the operational regime for a fusion power plant, we need to include the significant (and in many ways dominant) effects of fusion processes occurring on a large scale. We also need to operate at the right scales in order to benchmark engineering designs, and resolve power loading, energy extraction, tritium breeding, and materials issues. Substantial further progress on these fronts cannot be made until we have a fusion power dominated machine.

We need a strategy that continues to address the broad range of scientific and engineering issues of fusion. If we only attempt to address some of the key questions, then we will set back the timescale for fusion - further successor machines will be needed before we can go to a demonstration power plant. Quite simply, an ITER-scale machine is a pre-requisite in the route to fusion power. In addition, if we cease, or put on hold, key strands of research (such as developing self-consistent scenarios in the presence of alpha heating) this could lead to a loss of expertise and scientific momentum, which could take years to recover. ITER is the only option that allows a broad progression of all the necessary issues for fusion power. This is not to say that the objectives of fusion power might not be assisted by other devices (even in the presence of ITER), but it is important that we continue to work on all of the key questions. It is worth going through how ITER can address these (my apologies for boring the experts, but it is important to collect these arguments together). On the physics side ITER offers:

And on the technical/engineering side, it offers:

In many ways, these studies represent the logical next step of fusion physics and engineering programmes in the US. However, possibly as important, ITER offers a critical opportunity to integrate the fusion communities in each continent into a world-wide programme, large enough and coherent enough to be able to take fusion to the final stage of a demonstration power plant. The challenges in this remain substantial and wide-ranging - it is doubtful that a single continent could address these alone. Such coherence as exists in the world programme has already been stretched to the limit by the US refusal to even discuss ITER issues with other parties. A degree of cohesiveness has only been maintained by the hope of unifying around a new project. A US decision against ITER - to "go it alone" with a separate device - would inevitably lead to greater separation between the US and other fusion programmes. This would greatly hinder the scientific and technical progress towards fusion power. Ultimately, such disparity could be fatally divisive in agreeing the form of, and getting support for, the final step of constructing a fusion power plant. The world fusion community should work together to make fusion power a reality. In other areas of science such collaboration has been greatly beneficial. A good example comes from the field of particle physics where the US is leading key aspects of the LHC project at CERN, resulting in a highly successful collaborative project.

What about FIRE or IGNITOR as an alternative? These machines could of course make valuable contributions in some areas, such as benchmarking models of alpha particle effects. But as these are likely to be in the wrong scenarios and at the wrong scales for a fusion power plant, this would still be model testing, rather than directly addressing the issues of a fusion power plant and demonstrating solutions. Also, FIRE and IGNITOR simply will not address some of the key issues for fusion power. Simply from their scales they could not claim to be demonstrations of the structural design or integrity of power plant scale devices. Nor will they substantially assist resolution of materials issues, fuelling, ash removal, or scenario control and sustainment. Thus if going ahead with FIRE or IGNITOR leads to a substantial delay of ITER, this translates directly into a longer timescale for fusion energy. This could be a fatal blow for the fusion concept, because the length of the timescale is one of the greatest concerns raised by politicians with regard to fusion. Rather than increasing this to and beyond the (ever-promised) 50 year horizon, we need to aggressively pursue strategies to get it down. The only way to achieve this is by starting ITER as soon as possible.

So should the US go ahead now with FIRE or IGNITOR, in "support" of ITER? This could assist the development of fusion power, providing facilities able to focus more narrowly on particular issues. However, the adoption of such a strategy now is extremely dangerous. It is based on the false assumption that the EU/Japan will go ahead with ITER regardless. The funding for ITER is not yet settled in Europe or elsewhere. A second rejection by the US community (it would be perceived as this) would send a very negative message to funding bodies, being seen (incorrectly) either as a statement of not-readiness in scientific terms, or that ITER is not the right way forward. The timing of this is absolutely wrong, when the EU is presently deciding whether and how to pursue ITER, and if so, when to start construction. The drive for ITER has resulted in an unprecedented level of coherence and collaboration in the EU programme, which has taken years to build up. A major set back for ITER could brake the momentum of the entire EU fusion programme and leave it susceptible to cuts. Any resulting decline here could only have further negative repercussions in the US.

US funding could also make the difference between making ITER affordable or not. Whether or not there are sufficient funds for ITER in the EU fusion programme is still very much of an open question (even with Japan on board). It is not at all clear whether a decision to build ITER in the EU would release additional funds to construct the device. ITER's costs would push present EU fusion funding to the limit, and the price (the cutback of many existing fusion facilities and staff) may yet be too high for the EU to go it alone. In contrast US involvement could speed the build time of ITER, and thus for fusion power as a whole. It would also bring world-leading expertise to the physics programme of ITER in key fields, such as stability control or advanced scenarios.

This is not to say that "support" machines should not be built - facilities that are capable of assisting the resolution of some of the physics and engineering issues. It is merely arguing that this should not be at the expense of sacrificing the main goal of fusion power. Indeed, we should look to ways in which the ITER project can be supported. This could include devices such as FIRE or IGNITOR. However, there may also be merit in asking how we can get more out of present facilities, or build cheap, one-topic focused facilities. In particular, a critical element for fusion power remains materials development, and a dedicated materials test facility could speed progress substantially. Another example (from an EU perspective) is to release the full potential of JET, which has historically been under-powered: a significant upgrade could turn it into a modest Q facility, helping assess the physics effects of alpha particles and tritium technologies. No doubt there are a range of such projects and upgrades that would be relevant to the US.

So, the US has now reached a decision point on a major allocation of funds to progress fusion research to the next stage. It can choose to spend these on an expensive separate machine that will only provide limited research on a limited range of fronts - adopting an isolationist approach, leaving the international fusion community weakened, and sending a very negative message to other programmes world-wide. This would effectively opt itself out of what is the logical next step for many aspects of the present US programme. Alternatively, through ITER, the US can ensure the world programme is put on a solid path towards fusion power, by participating as a strong, equal partner in a vibrant, collaborative, international research programme that takes fusion to the power plant stage. Such a powerful collaboration could afford to explore a diversity of issues, via existing devices, upgrades, and other new devices, which we should consider in the future. Thus I urge the US to take this opportunity to decide for ITER now. The US focus has been divorced from the rest of the world's programme for long enough. The resolution of the issues of fusion energy production is a massive undertaking, with many aspects, requiring large resources. It is time for us to work together to secure the future for fusion.