Feeds

Nuclear reaction: what's next in energy science?

What to expect now even tree-huggers love nukes

Build a business case: developing custom apps

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

The Essential Guide to IT Transformation

Whitepapers

Implementing global e-invoicing with guaranteed legal certainty
Explaining the role local tax compliance plays in successful supply chain management and e-business and how leading global brands are addressing this.
Consolidation: The Foundation for IT Business Transformation
In this whitepaper learn how effective consolidation of IT and business resources can enable multiple, meaningful business benefits.
Backing up Big Data
Solving backup challenges and “protect everything from everywhere,” as we move into the era of big data management and the adoption of BYOD.
Boost IT visibility and business value
How building a great service catalog relieves pressure points and demonstrates the value of IT service management.
Why and how to choose the right cloud vendor
The benefits of cloud-based storage in your processes. Eliminate onsite, disk-based backup and archiving in favor of cloud-based data protection.