Feeds

Nuclear reaction: what's next in energy science?

What to expect now even tree-huggers love nukes

Security for virtualized datacentres

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

Security for virtualized datacentres

More from The Register

next story
Boffins who stare at goats: I do believe they’re SHRINKING
Alpine chamois being squashed by global warming
What's that STINK? Rosetta probe shoves nose under comet's tail
Rotten eggs, horse dung and almonds – yuck
Comet Siding Spring revealed as flying molehill
Hiding from this space pimple isn't going to do humanity's reputation any good
Kip Thorne explains how he created the black hole for Interstellar
Movie special effects project spawns academic papers on gravitational lensing
Experts brand LOHAN's squeaky-clean box
Phytosanitary treatment renders Vulture 2 crate fit for export
LONG ARM of the SAUR: Brachially gifted dino bone conundrum solved
Deinocheirus mirificus was a bit of a knuckle dragger
Moment of truth for LOHAN's servos: Our US allies are poised for final test flight
Will Vulture 2 freeze at altitude? Edge Research Lab to find out
prev story

Whitepapers

Why cloud backup?
Combining the latest advancements in disk-based backup with secure, integrated, cloud technologies offer organizations fast and assured recovery of their critical enterprise data.
A strategic approach to identity relationship management
ForgeRock commissioned Forrester to evaluate companies’ IAM practices and requirements when it comes to customer-facing scenarios versus employee-facing ones.
Security for virtualized datacentres
Legacy security solutions are inefficient due to the architectural differences between physical and virtual environments.
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.
New hybrid storage solutions
Tackling data challenges through emerging hybrid storage solutions that enable optimum database performance whilst managing costs and increasingly large data stores.