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Alternative approach to nuclear power

Posted: Sun Dec 23, 2018 1:17 pm
by Tony.Williams
Recognising that "green" energy sources such as sun, wind etc are too unpredictable and must be backed up by a dependable source of (preferably) non-polluting power, but faced with the financial horror story of the UK's attempt to build a new generation of vast nuclear power plants, I have recently been exercising the little grey cells (at least, those few which still answer the register).

The UK does design and build nuclear reactors - the ones which power our submarines. Obviously, they are much smaller than the commercial power plants, but that made me wonder about the possibilities of a power station consisting of dozens of these reactors - which are already developed and in (very slow) production by Rolls-Royce. Development costs should be low, while capital costs should fall with mass production. A power station could be brought on line in stages - one reactor at a time. Individual reactors could also be taken down for maintenance as required, or replaced by a newer and more efficient versions over time. The whole idea struck me as being far more flexible than the ginormous new reactors with their astronomical all-or-nothing costs.

So I did some web searching to compare power outputs and costs of naval vs commercial power plants (not that simple, there are different methods of calculating power outputs) and stumbled across this: https://www.rolls-royce.com/products-an ... ors.aspx#/ Rolls-Royce are effectively offering this already! Furthermore, I gathered from a 2017 newspaper report that the government was supposedly going to allocate £100 million to developing the idea. I was astonished that I'd never heard of this, as I take a mild interest in such technological matters. I hope it does get pushed forward - we need replacements for all our existing nuclear plants which are having to shut down due to their age.

Re: Alternative approach to nuclear power

Posted: Mon Dec 24, 2018 6:32 am
by chaggle
I've thought in those terms myself - but many smaller geographically separate power stations rather than large multi-reactor ones.

It is possible (and it's happening) to build micro gas-powered stations in something like a small industrial unit and one would have thought that similar could be done with nuclear.

Having many smaller generating plants builds resilience into the system although I suppose that must be balanced against the economies of scale of much larger plants.

Re: Alternative approach to nuclear power

Posted: Mon Dec 24, 2018 9:08 am
by Tony.Williams
chaggle wrote:
Mon Dec 24, 2018 6:32 am
Having many smaller generating plants builds resilience into the system although I suppose that must be balanced against the economies of scale of much larger plants.
I'm not at all sure of that in this case. Generally speaking, when it comes to equipment one big one is cheaper than several smaller ones of the same power. But against that you have to put the colossal resources required to build each big station, as demonstrated by Hinckley. The economies of scale as far as production is concerned may well favour lots of small units, since once the design is completed, you could just churn them out on a production line.

One issue which would need considering is security against terrorist activity. It shouldn't be too difficult to devise a reinforced concrete shell to encapsulate the plant, with a massive blast door to get through (it would also provide security against accidental release of radioactive substances). They make hardened shelters to protect combat aircraft on airfields:

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Re: Alternative approach to nuclear power

Posted: Mon Dec 24, 2018 10:09 am
by chaggle
Yes - security is a major consideration.

I would guess that geographically distributed plants would be less vulnerable to attack - or at least the redundancy would help secure supply.

Or maybe one vast plant is easier to defend. :con

Re: Alternative approach to nuclear power

Posted: Mon Dec 24, 2018 11:14 am
by Tony.Williams
Well, there is passive defence, such as the hardened shelter as pictured above, plus presumably some formidable fencing around the site with intruder detectors - the cost of that will be much the same regardless whether the reactors are concentrated or dispersed. Then there is active defence, as in security patrols, people on site ready to respond to any intrusions and potentially even short-range anti-aircraft missiles, which are much cheaper to provide if the reactors are concentrated. On the other hand, a major concentration of reactors would make a bigger and more spectacular target for terrorist attack, which could have more impact if operations are interrupted.

I was thinking in terms of a cluster of small reactors to replace an existing power plant (nuclear or fossil fuel), which could simply plug into the existing power distribution systems and networks. However, the option to use distributed plants might be attractive in other circumstances.