Energy future: time to be ambitious

Features editor

The middle of a nuclear crisis is the wrong time to comment on how it could have been averted. We don’t know any more than anyone else about the safety systems or maintenance schedules at the Fukushima Daichi complex; we can’t draw conclusions about the appalling aftermath of the earthquake and tsunami that stuck the plant last week; and trying to apportion blame is in extremely bad taste while plant operators and emergency services are risking their lives trying to bring the plant under control.

One thing that we can do, however, is to try to look at how technologists might respond to the aftermath of the Fukushima incident. It’s highly unlikely that this will herald the end of commercial nuclear power, but it’s inevitable that it will affect some of the ways in which plants are operated.

The problems with the cooling ponds at Fukushima could lead to new research into ways to store spent fuel. It’s clear that spent fuel represents a hazard, and new ways of handling and storing it are needed.

Many people believe that thorium represents a better option for nuclear fuel than uranium — we’ve seen several comments to that effect on our articles covering Fukushima — and more projects looking into this are likely. Thorium is more abundant than uranium and, according to some nuclear experts, can generate more energy per kilogram of fuel; it’s also believed to be impervious to meltdown. However, considerable development is needed to develop thorium technology to commercial levels.

Increased deployment of renewables is another option. Wind power is unlikely to be rolled out to any greater extent than is already planned, unless some way of solving the problem of intermittency can be found. For regions with the resource, development of tidal power could be accelerated, with widespread deployment perhaps in the next decade. But it will still only provide a fairly small fraction of the electricity requirement (although a large amount of power). Unless very large improvements in energy efficiency and a drastic reduction in energy usage can be achieved — leading to very significant changes in lifestyles — other options will still be needed.

But the biggest and most alluring development target is the elusive goal of nuclear fusion. If there were ever an example of how a concerted, international research project could reap dividends, it’s this. The potential is obvious: fusion, if it can be made to work commercially, could provide power safely, with no chance of explosion and much lower radiological hazard; sustainably, using lithium and deuterium from seawater; and with no possibility of profusion of nuclear weapons.

That’s not to say it’ll be easy. The challenges are still immense, as the recent problems besetting the ITER fusion project demonstrate. If the magnetic confinement version of fusion is to work, we need further development in superconductors to run the huge magnets the system depends upon to compress fusion fuel; we need to develop materials to build the doughnut-shaped reactor vessel that can withstand the hot plasma and neutron bombardment inside; and we need to develop the systems to convert lithium into tritium, the hydrogen isotope which fuses with deuterium to form helium, accompanied by the release of energy.

The other form of fusion, using powerful lasers to force pellets of fusion fuel to implode, also requires development: design and production of fuel pellets; the control systems to coordinate the release of pellets and the firing of the lasers; and not least, the enormous lasers themselves. These plants are the epitome of high technology and, if they are to form a commercial power source, some way needs to be found to bring the price and complexity down. The US National Ignition Facility in California expects to determine whether it can generate net energy from laser fusion in the next couple of years.

There’s no denying fusion is a huge challenge, and one that will need equally huge resources to tackle. And it might not work; it’s undeniably a gamble. But humanity has tackled huge, and seemingly impossible, tasks before; twice in the last century, with the Manhattan Project and the Apollo missions. Keeping fusion in sight as a goal could render nuclear fission in a new concept: as a stopgap on the way to a much cleaner and safer source of energy. Perhaps we need to stop seeing fusion as pie in the sky, but as a goal for this and future generations, and start thinking very seriously about it.