Small-scale and very-small-scale nuclear power

[mattbell]

I recently learned of a new generation of nuclear power technologies that, if successful, will change how people think about nuclear power.

Many of the negative views about nuclear power came from the first generation of nuclear plants built during the '50s and '60s. From what I understand, these plants are trickier to operate, have a greater risk of meltdown, and produce more nuclear waste than modern reactors. Most of them are still in operation despite their aging status because there is opposition to building new nuclear plants in the US. Other countries that started deploying nuclear plants more recently tend to use more modern designs. France actually runs almost entirely on nuclear power. ( http://en.wikipedia.org/wiki/Nuclear_power_in_France )

However, the technologies I've seen recently look at using small nuclear power plants as ridiculously long-life batteries.

Hyperion claims to be refining a design for a nuclear reactor that would fit inside a truck and power a community of ~25000 homes for 7-10 years. It's totally self-contained and (they claim) it's extremely resistant to meltdown. We'll see if they actually deliver in 2013. Small reactors could power more isolated towns, large factories etc.

For the extremely micro-scale, there's this technology, which is essentially a tiny nuclear reactor on a chip. It produces electricity more or less directly from nuclear decay of tritium. It can't produce much power, but it can run a small remote device for 10-20 years.

Comments

[maradydd.livejournal.com]

I hope you're right about these technologies changing people's minds, though I'm dubious about whether they will or not. I've been excited about third-gen nuclear, such as the Integral Fast Reactor and the pebble bed reactor, since I was in high school -- these are reactors that are engineered so that they can't melt down (there's never enough fissile material present to achieve meltdown temperatures), they recycle their own waste, and in the case of the pebble bed, run off thorium rather than uranium (thus no hazardous uranium mine tailings -- the most abundant source of thorium in the world is the sand on a particular stretch of India's coastline) and have a fuel lifecycle which consists entirely of materials that can't be used in bombs. (The intermediate uranium isotope produced -- U-233, I think -- interferes with electrical circuitry.)

I've been advocating these technologies for over a decade, and it's depressing how difficult it is to get most people to get over their gut "OMG, Chernobyl!" response and take a serious look at how different they are from first-gen light-, heavy-, and boiling-water reactors.

OTOH, I got into a discussion recently with a Greenpeace guy here in town, and he actually listened to me, so maybe Europe is different.

South Africa and China have pebble bed reactors under construction and coming online soon, at least.

[nasu-dengaku.livejournal.com]

Do you happen to know much about the total lifecycle cost of modern nuclear plants, including construction? How does it compete with renewables?

[happyinmotion.livejournal.com]

The Hyperion approach is interesting, if they can deliver what they claim. However, the real red flag in their approach is the cost. They claim 30% cheaper capital costs. Frankly, with a few cost over-runs here, and some regulatory delays there, their margins turn to custard, and if there's one thing we've learnt about nuclear engineering over the last fifty years, it's that nukes always cost more than predicted.

In other news, solar, wind, geothermal, and marine continue to plummet in price....

[maradydd.livejournal.com]

The person to talk to about that is the guy who blogs at http://www.depletedcranium.com -- if he doesn't have an immediate answer, one of the regular commenters will.

Also, the math on renewables is interesting because with the exception of hydroelectricity and geothermal, they all require spinning reserve to provide baseload power. Wind is especially bad about this, but solar needs it too -- and spinning reserve is typically coal.

[easwaran.livejournal.com]

Isn't something like this the way nuclear submarines and nuclear icebreakers work? At least, I assume it's got to be something like this, because regular nuclear power plants are so huge in terms of their power output that I can't imagine a submarine using that much power unless it moves by evaporating the ocean in front of it and recondensing the water behind it.

[happyinmotion.livejournal.com]

It's a tad more complicated than that.

You need spinning reserve to deal with instantaneous outages, i.e. equipment failures. For renewables, you need a backup that can come on line in the same time that the renewables can go off line. You also need such backup to cope with changes in demand and those changes vary on a range of timescales. (The canonical example was the UK, where having only two major TV channels meant that at the end of a big film, half the nation would pop to the kitchen and turn on the kettle. 10% rise in national power demand in one minute, or so I'm told.)

The output from any one wind farm is pretty predictable on an 15 minute basis. For an entire nation, wind power is predictable on a daily basis. Solar is variable throughout the day, but predictable on an hourly basis. Tidal is awesomely predictable. Hydro is predictable on a monthly basis and (depending on your storage), is variable on a a weekly-to-yearly basis.

So you've got variable supply and variable demand. There's a range of load-matching techniques available. NZ has lots of hydro for rapid turn on. UK has special pumped storage for the kettle problem. Fast-start gas stations work wonders, have cheap capital costs and only have fuel costs when running. If you've a geographically big enough nation and decent transmission, then variability is less of a problem, coz somewhere is always going to be windy.

I'm more familiar with the UK and NZ power systems than the US, but it seems you can grow wind to 25-35% of your total generating capacity before variability becomes too expensive to deal with. Similarly, for nations where air conditioning gives a peak daytime load, solar matches that peak very nicely.

So the answer is that it's complicated, and there's lots of mis-information out there, but the variability of renewables isn't a reason to avoid renewables.