nuclear-news.info

Small nuclear reactors – untested and expensive

Nuclear energy: Flexible fission, Ft.com,  By Sylvia Pfeifer  14 Feb 13,  At the Baltic Shipyard in St Petersburg squats the hull of the Akademik Lomonosov. It is no ordinary ship. Once it is finished in three years’ time, it will be Russia’s first floating nuclear power plant.Two reactors, similar to those used in Russia’s nuclear-powered ice breakers, will each provide 35 megawatts of power. The floating power plant is one of several planned by the Kremlin to be anchored near towns or industrial sites……

Critics are wary, warning that floating atomic power stations would make an ideal terrorist target and be vulnerable to stormy weather and earthquakes. Others point out that even if smaller reactors had less fuel and were partly buried underground, there would be an increasing number of small facilities dotted across emerging markets, sometimes in places that lack the infrastructure to cope with emergencies….

multiple challenges remain.

There are questions over whether the regulatory regime and siting criteria should be relaxed for these reactors? There are also suggestions the plants could be run with fewer staff, helping to cut the costs even further.

Dame Sue Ion, a nuclear fuel expert and fellow at the UK’s Royal Academy of Engineering, says the first small modular reactors will, realistically, be sited on existing nuclear-licensed sites.

“It may be that the physical characteristics make it safer but you would still have to have all the safety arrangements and emergency planning in place,” she adds.

“You still have the same safety, proliferation and accident concerns,” says Doug Parr, chief scientist and policy director at campaign group Greenpeace UK. “You need capacity and supportive infrastructure to respond if there is an emergency.”

Then there is the issue of public acceptance. “To expect the general public to just accept them because they are small is pushing the point. It does not seem obvious to me,” Kevin Hesketh, senior fellow at Britain’s National Nuclear Laboratory,  told an industry conference last month…….. “Licensing and public acceptance – both have to be addressed. ..

The biggest challenge facing the model is simply that no one has done it. Nuclear also has a bad record on cost. At the same time, competition from renewables, which are becoming cheaper, is growing.

Dominic Holt, associate director, nuclear advisory, at KPMG, says “none of the positives have been tested yet”. Claims of cost and programme certainty are still unproven. Analysis of a range of available data show that the “levelised cost” – per MW/hour – of SMRs is still similar to that of a large reactor…

April 12, 2013 Posted by Christina MacPherson | REACTOR TYPES | Leave a Comment

Small Modular Nuclear Reactors (SMRs) – not safe, not cheap

More backup systems, he pointed out, would drive up the cost of small reactors, which already have a sizable economic disadvantage compared with large reactors. Because of economies of scale, the capital cost per kilowatt for a small reactor would be approximately 250 percent more than that for a large conventional reactor.

Lyman warned about allowing the industry to site small modular reactors in remote areas or developing countries that have no nuclear experience or emergency planning infrastructure. “UCS believes that [small modular reactors] are only suitable for deployment where there is an established infrastructure to cope with emergencies, and if sufficient numbers of trained operator and security staff can be provided

Nuclear Expert Dispels Myths about Small Modular Nuclear Reactors in Senate Testimony http://www.ucsusa.org/news/press_release/nuclear-expert-dispels-myths.html WASHINGTON (July 14, 2011) -- A physicist from the Union of Concerned Scientists (UCS) today testified before a Senate subcommittee that small modular nuclear reactors are not necessarily any safer or more secure than conventional size reactors and could be more dangerous. Companies vying to sell small reactors, he said, are overstating their benefits and downplaying their potential pitfalls.

“Although some light water [small modular reactor] concepts may have desirable safety characteristics,” Edwin Lyman, a senior scientist with UCS’s Global Security Program, told the Senate Appropriations Committee’s Energy and Water Development Subcommittee, “unless they are carefully designed, licensed, deployed and inspected, [they] could pose comparable or even greater safety, security and proliferation risks than large reactors.”. Read more »

December 28, 2012 Posted by Christina MacPherson | REACTOR TYPES | Leave a Comment

Small Modular Nuclear Reactors (SMRs) have lost their appeal for USA Department of Energy

ultimately, the decision may have come down to the commercial prospects for the technologies. The fact remains that the economics of all of these designs remains murky.

Based on economies of scale, small reactors will produce more expensive electricity than large reactors, all other factors being equal.

Does DOE’s Funding Announcement Mark the End of its Irrational Exuberance for SMRs? http://allthingsnuclear.org/does-does-funding-announcement-mark-the-end-of-its-irrational-exuberance-for-smrs/?utm_source=twitterfeed&utm_medium=twitter&utm_campaign=Feed%3A+AllThingsNuclear+%28All+Things+Nuclear%29 Ed Lyman, senior scientist
November 21, 2012
 On November 20 DOE finally announced that the Babcock and Wilcox Company (B&W) and its “mPower” reactor were the lucky winners of its Funding Opportunity Announcement (FOA) for a cost-sharing program with industry for the design and licensing of “small modular reactors,” or SMRs.  Although DOE had originally said the announcement would come in July or August, it decided instead to bury it on Thanksgiving week – not usually a time the agency releases news of which it is particularly proud.

And in fact, the real news is not that a grant was awarded to B&W – this was a near-certainty – but that there was only one winner instead of two. While the initial FOA specified the program was meant to fund “up to two” projects, the widespread expectation was that two grants would be awarded to the pool of four applicants. Read more »

December 28, 2012 Posted by Christina MacPherson | REACTOR TYPES | Leave a Comment

Underground nuclear reactors plan faces intractible problems

Just build them underground! http://daryanenergyblog.wordpress.com/ca/part-10-smallreactors-mass-prod/10-2-2-just-build-them-underground/ There is a common misconception, that we could solve a lot of the problems with reactor construction, both large and small (though in particular the small ones) by building them in subsurface pits. I’m assuming the person who thought up this one has never dug a hole in his back garden! If you have, you’d know that digging a hole is not as easy as it seems. Firstly, the soil type has a big bearing on things. Depending on where you live you could be looking at thick sticky soil that difficult to shift, loose gravely soil that collapses easily or rocky earth, that rapidly turns into bedrock (so after a while you’re not digging any more but blasting!). As we need to put foundations down under out reactor to suit the soil type, and probably piling too (due to its weight), this means we essentially need to design each reactor’s containment vessel individually to suit local soil conditions, which increases costs.

Another problem is water intrusion, as anyone who’s ever dug a pit, then gone in for lunch, come back out and found it full of water will know all about! Our reactor “pit” needs to be designed like the hull of a boat to stop water leaking in and flooding it. Doing that with concrete, particularly thick section of it, is always difficult. The fact that the reactor will be generating heat complicates things as it raises the risk of subsidence or settlement cracking. While this can happen if the reactor is on the surface too, putting it under ground level “complicates things”.

In general with any construction project significant efforts are made to reduce the amount of earth movement required to start construction, not increase it, as lots of earth moving nearly always results in delays, hold-ups and ultimately higher costs (not the least of those being the cost of hiring out of earth moving equipment, those guys charge an arm and a leg!).

Overall, except in a small number of narrow cases building reactors this way will often work out as more expensive and slower than just putting the containment dome above ground.

August 16, 2012 Posted by Christina MacPherson | REACTOR TYPES | Leave a Comment

Future nuclear reactors – are they viable?

By D A. Ryan,  Once upon a time I used to be a fan of nuclear energy. As far as I saw it, nuclear energy was the silver bullet solution to all of our energy problems and more. However, the more I’ve learned about the industry the more critical I’ve become.

Notably the fact that most of the economic figures in support of nuclear power (a couple of typical delusions you’ll find here and here) come straight out of Hogwarts school of magic, wizardry….and economics (more realistic appraisals of nuclear economics can be found here and here).

All in all my conclusion is that the case for future Generation IV nuclear reactors is much narrower than the supporters of nuclear energy would have you believe. While they do offer some advantages over LWR’s, notably in the area of safety, this comes with strings attached, notably higher capital costs. This is largely a result of the fact that many of these would need to be built from much more exotic materials, such as high temperature stainless steel alloys  Nickel alloys or Refractory materials, while the predominant material of choice in current reactors is steel (stainless and forged ferritic) and concrete. This materials requirement is itself an issue related to the high temperatures these alternative reactors would be required to operate at, not to mention the more aggressive and corrosive environment in some of them, notably the MSR proposals. Of course one to question whether these higher construction costs (and in some cases higher decommissioning costs) are justified……..

Small to medium sized modular reactors do offer a good deal more flexibility in terms of how nuclear power could be used and yet a further improvement in safety. However, they also comes with lower economies of scale and thus higher construction costs and worse a slower rate of reactor roll out (at least in the early days). We could claw back on these two issues by mass producing said reactors in large volumes but as I point out (again see the full article), it is far from proven whether that would be economically viable and whether there is in fact a market for large numbers of small reactors…….
by and large mass production means “dumbing down” our design, and that means accepting a reactor that’s much cheaper and easier to build but has a lower thermal efficiency, a higher rate of fuel consumption and ultimately produces larger volumes of nuclear waste compared to our “mega” reactors. With the exception of a small number of narrow cases, it’s difficult to envisage how this would offer an improvement on the current status quo…..

August 16, 2012 Posted by Christina MacPherson | REACTOR TYPES | Leave a Comment