杏吧原创

Editorial: 鈥�Don鈥檛 let nuclear renaissance bury carbon capture鈥�

THIS could be the start of something big. In the next few weeks, the UK government is expected to sign a deal to start building the country鈥檚 first new nuclear reactors for 25 years.

The reactor design is more efficient, and safer, than those in existing plants. They are also good news in terms of climate change (see 鈥�Shooting at climate targets鈥�), but what they will do to energy prices is less clear. If the plan is to improve the UK鈥檚 green credentials and energy security, however, yet more reactors are needed.

Assuming the deal goes ahead, the two reactors, which could cost about 拢14 billion, will be built at on the Somerset coast, which already has two nuclear power stations, one of which is now being decommissioned. Once up and running, the two reactors will provide about 7 per cent of the UK鈥檚 electricity. They will be built by a consortium led by EDF Energy and will be half-owned by China.

The reactors will be , developed by French energy giant Areva. They are a variant on the pressurised water reactor, so named because the cooling water surrounding the reactor core is kept at high pressure to prevent it from boiling (see diagram). The design features crucial advances. It generates more electricity from less fuel and needs less downtime for maintenance. It also cuts the risk of major accidents. 鈥淚t is unquestionably a safer system,鈥� says Timothy Abram of the University of Manchester in the UK.

The reactor building will be more resistant to aircraft strikes. Before 9/11, reactors were only built to survive the impact of a crashing fighter jet. 鈥淚t never occurred to us that anyone would do this deliberately,鈥� says Abram. Modern aircraft can have engines as big as buses, which could punch through concrete. So the Hinkley reactors will have two concrete walls, each more than 1 metre thick.

Lessons have also been learned from the 2011 Fukushima disaster. There, the reactors shut down safely after an earthquake, but a tsunami then knocked out the back-up diesel generators. Without power, cooling systems failed and the reactors overheated. To prevent this, Hinkley will have six generators instead of four, in widely spaced waterproof buildings.

In the worst case, the EPR should contain a meltdown. As in previous designs, the reactor will be built on a 6-metre-thick concrete base to stop the molten core burning through the floor. But in the EPR, channels carved into the concrete will allow the mess to spread out. Combined with underfloor cooling, this should quickly bring down the temperature of a molten core.

It will be years before the Hinkley reactors generate electricity, however. UK energy regulator Ofgem assumes it will be after 2018. In the meantime, many . Ofgem says the , while still low, will quadruple between now and 2015.

And Hinkley could still arrive late. Being a new design, EPRs have been delayed and over budget. The world鈥檚 first EPR at Olkiluoto in Finland is still not finished after eight years. Construction started on an EPR at Flamanville in France in 2007, but completion has been delayed until 2016. However, two EPRs at Taishan, China, should be finished within a year. Hopefully, EDF and Areva will have learned from these experiences.

In the meantime, the sticking point is the price of Hinkley鈥檚 electricity. EDF wants a 鈥渟trike price鈥�, guaranteeing them a minimum fee. That could inflate . But to improve energy security and cut emissions, it may be a price worth paying.

鈥淚t鈥檚 probably the only way you鈥檙e going to get a nuclear power plant built by a private company,鈥� says Jim Watson of the UK Energy Research Centre in London. He says the UK鈥檚 energy prices are mainly driven by the cost of gas, and avoiding pricey options like nuclear and renewables might not save much.

With Hinkley, the UK will join the US in building its first reactors for decades. This cautious nuclear renaissance is dwarfed by China where 29 reactors are under construction. That鈥檚 the right approach, says Watson. A single plant is costly, but building several creates economies of scale. 鈥淭he only way to do nuclear cost-effectively,鈥� he says, 鈥渋s if you do many stations.鈥�

This article appeared in print under the headline 鈥淭he New Nuclear Generation鈥�