Feeds

Nuclear reaction: what's next in energy science?

What to expect now even tree-huggers love nukes

New hybrid storage solutions

Pebbles: The 'politically correct' reactor

Koeberg's pebble-bed reactor

Eco-friendly? Koeberg's PBMR project never got off the ground.

Another remarkable innovation in nuclear energy is the pebble-bed reactor, variously described as the " politically correct atomic reactor" [pdf], or the nuclear power plant you could leave in the hands of Homer Simpson.

The idea isn't new, it was first demonstrated in 1967. But with traditional concerns about nuclear plants (such as meltdown) made moot by the inherently safe design, it's curious that pebble-bed designs are not common. It seems they should be as common as neighbourhood transformer stations. (Reactors used in nuclear-powered icebreakers are as small as 35MWe.)

South Africa last month signalled it would end its 11-year PBMR (Pebble Bed Modular Reactor) project, shedding most of the 800 staff working on the project.

China and Germany continue to develop designs similar to the PBMR.

A pebble bed reactor design
Source:European Nuclear Society

"It's always the bridesmaid," says Grimes. "I'd like to see it developed. As scientists, we need that flexibility of technologies going forward. PBMR is inherently safe and it's modular. But the small LWR reactor designs are also modular in the same way, and in terms of safety, the AP1000 has equivalent safety features such as passive cooling. The advantages of PBMR are definitely starting to be clear in the LWR design. That's taken the wind out of its sails."

"In a traditional reactor design, the decay heat – once fission has been turned off – is enough to destroy the reactor core. There are two things you can do - even if you lose your water, you can have a passive water volume that flows through the reactor from big tanks on the roof. You don't have to do anything - it's a passive process. Even though water's running out, it's removing the decay heat. It is exponential decay - so the residual amount of heat is no longer a threat. However there are additional features - natural convective processes that keep water moving around outside and keep the vessel cool. It's really simple."

Nuclear still leaves proliferation problems, but as Grimes points out, "nothing is proliferation-resistant, there are just degrees of it."

And fusion?

"Sure it's possible. JET has been a great success, there's no question. But JET is a long way from a commercial reactor; even ITER is a long way from a commercial reactor. We need an entire generation of fission reactors with 60-year lifetimes."®

Andrew welcomes your emails

Providing a secure and efficient Helpdesk

More from The Register

next story
Boffins: Behold the SILICON CHEAPNESS of our tiny, radio-signal-munching IoT sensor
Single ant-sized Stanford chip combines radio, 'puter, antenna
Thought that last dinosaur was BIG? This one's bloody ENORMOUS
Weighed several adult elephants, contend boffins
Drones swarm over bearded Brit billionaire's island getaway
Just to take lovely pictures though, after Richard Branson invests in 3D Robotics
Chelyabinsk-sized SURPRISE asteroid to skim Earth, satnav birds
Space rock appears out of nowhere, buzzes planet on Sunday
California blue whale numbers soar to historical levels, say boffins
Still far too many of them being struck by US ships, mind
City hidden beneath England's Stonehenge had HUMAN ABATTOIR. And a pub
Boozed-up ancients drank beer before tearing corpses apart
'Duck face' selfie in SPAAAACE: Rosetta's snap with bird comet
Probe prepares to make first landing on fast-moving rock
prev story

Whitepapers

Secure remote control for conventional and virtual desktops
Balancing user privacy and privileged access, in accordance with compliance frameworks and legislation. Evaluating any potential remote control choice.
Intelligent flash storage arrays
Tegile Intelligent Storage Arrays with IntelliFlash helps IT boost storage utilization and effciency while delivering unmatched storage savings and performance.
Reg Reader Research: SaaS based Email and Office Productivity Tools
Read this Reg reader report which provides advice and guidance for SMBs towards the use of SaaS based email and Office productivity tools.
Security for virtualized datacentres
Legacy security solutions are inefficient due to the architectural differences between physical and virtual environments.
Providing a secure and efficient Helpdesk
A single remote control platform for user support is be key to providing an efficient helpdesk. Retain full control over the way in which screen and keystroke data is transmitted.