Comment by niftich | Hacker News Reader

Comment by niftich | Hacker News Reader

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Some of nuclear energy's challenges get a good amount of coverage: politicians unwilling to support it, citizen opposition, and cost overruns and delays at plant currently under construction. Others, less so. And if we discount politics for a moment, the day-to-day economics of new nuclear barely pencil out. Nuclear needs immense capital expenditure vs. other types of generation. Solar gets generous subsidies and doesn't need a lot of opex, wind is similar. And in the US, natural gas is cheap and plentiful, and pairs well with intermittent renewables, and load-following gas turbines are blurring the distinction between baseload generation and peakers.

Despite the wishes of many, pollution externalities are not priced in, and while that is the case and fracking continues to bring up cheap gas, the rule of natgas will continue.

But nuclear's immense capex is a problem nonetheless. While reactor designs purport to be off-the-shelf, the each plant itself is a one-off. There's no institutional memory and hardly any re-use of expertise, there's no economies of scale -- just all the hallmarks of difficult megaprojects. Sound familiar?

This is why research into 'small modular reactors' is promising. Plenty of political barriers remain, but removing some institutional barriers and easing some of the economic ones would improve nuclear energy's prospects.

Existing nuclear plants got as big as they are because of economies of scale. Turns out that a plant twice as big costs less than twice as much as two smaller ones.

But, due to nuclear expansion faltering we build too few of these plants, and thus all of them become essentially first-of-a-kind, which tends to mean a lot of (very expensive!) delays.

I also think SMR's are very promising, trying to break the cycle of ever-increasing costs of big plants through mass production (and passive safety) rather than just making them as big as possible. Think airliner factory rather than one-off megaprojects.

They also got big because of economies of scale of operation. Making a reactor smaller doesn't proportionally scale down the staff you need to operate it. This is relevant when as many as a third of reactors in the US are not even making an operating profit.

SMRs will require changes to operational regulation if they are to compete.

Indeed. Many microreactors of the past like the PM3A in Antarctica were just too expensive to operate and maintain so they got replaced with oil. SMRs are great for lower capital cost but they won't just automatically be cheap to operate. The nuclear industry has to focus heavily on getting maintenance and operation costs way down. Some of that is regulatory, but lots of it is inherent.

This is the most important point regarding nuclear if you ask me. If it is to have any chance at a rebound, it has to start from smaller reactors again. And it has to do be a design that's geared towards load-following rather than baseload, so that it complements renewable rather than compete with it.

The focus now should be on massive investments into R&D and smaller scale developments

There are lots of people considering steam bypass, where you can shift the heat from any reactors away from the turbogenerator and into some industrial process like desalination or pulling carbon in from atmo.

I have heard that France standardized it's nuclear design, and has been very successful with that. Not exactly COTS, but not like starting over each time either.

So has Korea and for a time, Japan. That is absolutely key and has led me to promote the idea of open source nuclear reactor design.

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