The next STEP to fusion: Interview with Professor Howard Wilson

The STEP (Spherical Tokamak for Energy Production) programme, announced in October 2019, is an exciting £220M venture to design a viable fusion power station, which could be operational by 2040. STEP Programme Director Professor Howard Wilson tells us more about the programme and whether he thinks fusion can really address our future energy challenges.

This article first appeared in the Nuclear Industry Association’s Industry Link magazine and is reproduced with kind permission.

So Howard, you’ll have heard many times the phrase ‘fusion is 30 years away…’ – what makes you think the STEP programme can make fusion energy a reality? 

Indeed. When I started my career at Culham – 30 years ago, coincidentally – I hoped to see fusion power to the grid within my career.  Clearly that hasn’t yet happened. However, the brilliant work that’s been done by scientists and engineers around the world during that time means that we are now better placed than ever for the push to deliver net fusion power.

Consider the UK position. One of our strengths is the broad range of facilities we have right here at UKAEA’s Culham site in Oxfordshire – from the world’s most advanced fusion experiment, JET (which we operate for the European Community), to the newly upgraded innovative MAST Upgrade fusion experiment (funded by the EPSRC).

These are supported by a range of other facilities, including the Materials Research Facility which tests the properties of irradiated materials, the Remote Access in Challenging Environments (RACE) facility which is developing advanced robotics and remote maintenance systems and a new tritium science facility (H3AT), which will open in 2021.   The capability of these facilities, together with the outstanding calibre of UK fusion scientists and engineers – both at UKAEA and in industry and academia – means we can now be confident about entering the fusion delivery era.

This is the ambition of the STEP programme – counting down the years to deliver the world’s first fusion reactor by 2040 and demonstrate net electricity production. There is no doubt that STEP is an ambitious programme – but one the UK is well-placed to deliver.

Tell us more about the STEP programme…

A major benefit of fusion energy is that it produces no greenhouse gases and, with the world likely to need ever more energy, it’s unlikely that conventional renewable energy will be able to meet this need.

Fusion is an attractive option – its high power density complements conventional renewable energy sources to meet future demand and counter the threat of climate change. There is a need to accelerate fusion research – this is why we need STEP.

STEP is a programme that is packed with adventure, aiming to design and build the world’s first compact fusion reactor by 2040, capable of demonstrating the commercial viability of fusion power by delivering net electricity. STEP is a prototype and will point the way to a fleet of commercial fusion reactors to be deployed around the world.

The ambition of the STEP programme is to deliver the world’s first fusion reactor by 2040 and demonstrate net electricity production.

In October 2019, the Prime Minister announced £222 million funding for the first stage of the work, to be complete by March 2024. The key deliverables for this stage are to develop a concept design for the prototype reactor, deliver technical solutions, define the regulatory framework and identify a suitable site.

At the end of stage one, the programme will be reviewed and, if successful, a second tranche of funding, which is anticipated to involve commercial investment, would enable detailed engineering design and then construction.

On our current timelines we envisage construction beginning in 2032, with operations from 2040.

What do you think are the main challenges?

The main technical challenges are to do with plasma physics and materials and UKAEA is working with strong UK university groups to address these issues. The new MAST Upgrade spherical tokamak is a key testing facility for many of the plasma physics issues; our Materials Research Facility seeks to understand and optimise materials for the extreme fusion conditions, and our RACE team works to optimise the robotics and sensing equipment for remote maintenance and operations.

Another challenge is the accelerated timeline of the STEP programme, which means that the engineering design will be developed before data from the deuterium-tritium mix plasma fuel is available from ITER, the international fusion device being constructed in the South of France. This creates the need for an innovative approach to licensing and construction and the use of digital engineering to underpin design methodology.

A third challenge is to do with tritium as it will need to be bred and managed within the reactor. The H3AT tritium science facility will undertake research and development in this area, both for STEP and for ITER.

It’s absolutely crucial that we build a coalition of support and ensure our stakeholders are confident in our ability to deliver. This, together with the know-how and intellectual property we generate, will be required to attract the commercial investment needed to fund the engineering design and construction phases.

The ambition required to tackle these challenges, combined with the critical goal to address climate change, mean that STEP is one of the most exciting programmes in the world. It is recruiting the very best scientists and engineers right now – come and join us!

What about the supply chain, what are the opportunities?

There are growing and thriving fusion companies in the private sector, all of whom have potential to make significant contributions to the delivery of successful fusion energy in their areas of specialism. We look forward to partnering with them on this journey.

There will be many opportunities for the supply chain and our recent event, held in Coventry in February, outlined our plans for STEP, as well as the wider work of UKAEA.

STEP is about UKAEA working in partnership with industry and academia in a national programme. In this way, we ensure the supply chain and skills grow with the programme and establish the necessary national capability to build and operate the STEP prototype reactor.

All our supply chain opportunities are posted on the UKAEA website and we’re looking forward to further expanding our relationships as the programme progresses.

How will a site be chosen?

The site will be selected on the basis of communities volunteering to host the facility and we’re already working with the UK Government to develop an open and transparent process to work towards that.

We haven’t yet begun to engage with communities on the potential benefits of hosting the world’s first energy-producing fusion reactor and this is in our workplan for 2020.  As with any major infrastructure project, we know there will be significant social and economic benefits to the host community and we are confident that many will come forward. Quite apart from the immediate benefits to the host, producing the first net fusion energy in the UK will be a landmark event that will be internationally recognised for decades, if not centuries to come.