BRITAIN PLANS COMMERCIAL HOT-FUSION REACTOR

The British government is seeking a site for what would be the world’s first commercial fusion reactor. The device would heat hydrogen gas to the temperature of the sun’s surface to melt hydrogen atoms together, unleashing vast energies and providing clean power in more quantities than the device uses.
So-called “hot fusion” has been in development for more than 40 years but has yet to prove the reaction can be sustained long enough to deliver electricity affordably and reliably.
The new project called the Spherical Tokamak for Energy Production (STEP), is intended to commercialize a simplified fusion reactor design dubbed the Mega Amp Spherical Tokamak, which was successfully test-fired in October at the U.K.’s Culham Centre for Fusion Energy.
STEP’s construction budget is said to be less than $10 billion, cheaper than a conventional nuclear power generating plant. It also won’t be able to breed tritium, a lethal radioactive element. But STEP will need tritium to ignite its reactions, so operators will need to import the scarce and dangerous material from elsewhere. 
Also, plasma heated to millions of degrees F in a small space will be hard on materials, and STEP will have to be shut down periodically so interior parts can be replaced.
The push to build STEP might not be entirely technological.
The British government’s major previous fusion project is winding down, leaving a cadre of fusion engineers with little to do. Also, the U.K. might lose its role in Europe’s joint fusion program if it doesn’t work out a successful Brexit deal.
In addition, two private-sector start-ups are hot on the trail of commercial fusion power: Tokamak Energy, a British venture, hopes to build a working fusion reactor by 2030; Commonwealth Fusion Systems in the U.S. plans for one to be ready by 2025.
In contrast, STEP is slated to begin construction in 2032 and start delivering electricity by 2040.
TRENDPOST: Hot fusion technology has never shown an ability to deliver a sustained reaction that justifies a commercial project, much less the investment required to build one. There is no evidence it can be made practical, especially when the cost of renewable energy continues to plummet and the world is moving to decentralized power generation.
As a research field, hot fusion suffers from a case of what economists call “sunk costs:” governments have invested tens of billions in it over decades; respected scientists have built their academic careers and credentials in the field. To pull the plug now and admit hot fusion’s impracticality would be to admit past investments of money, time, and careers were wasted – an admission that none of the players seem yet to be able to make.