Towards a Navy Corps of Nuclear Engineering | Hacker News Reader

Towards a Navy Corps of Nuclear Engineering

professorbainbridge.com

17 pointsrobg29 comments

This is actually a pretty reasonable idea. There are several considerations that need to be worked out first. Specifically:

1) there are few programs in the entire US which have nuclear engineering degrees (MIT has one, I believe fewer than 10 others do too), a topic requiring a sufficiently broad range of skills that its almost like a fusion [sic] of solid state physics (for robust materials), electrohydrodynamics (to understand anything relating to fusion and plasma), numerical computing (analytic solutions to realistic PDEs is a funny idea sometimes), as well complete case analysis of all possible risk and failure modes via probabilistic model building (there is in fact dedicated software used to handle the complexity of these models). In short, do we have the educational capacity to train the people needed?

2) at least with how current nuclear regulation is structured (which would presumably have to change), technically any new reactor designs that get approved are "exemptions" to a general ban, so theres actually a lot of time spent finaggling approval via a somewhat insidery process.

3) I want fusion thats commercially viable! :). The idea of having energy become functionally free and what would then be possible boggles my mind, and I don't think anyone can fully comprehend the myriad subtle ways in which the world would immediately change. Also, while in practice dealing with fission products/waste isn't that bad (and its much more contained than waste from conventional power plants), it is logistically tricky to manage both the waste and all the people who worry about the waste.

Carter,

Where did you get the idea that fusion power is functionally free?

The fuel you burn is nearly free, but you also use up a ton of material and make it radioactive so it's hard to recycle. The structural and shielding elements of the reactor will likely degrade (for we haven't tested this) on a similar timescale to the degradation of wind turbines, solar collectors, and the other components in the balance of the plant.

The heat from the sun and at the core of the earth is functionally free, in the same sense: the question is how expensive it is to get it out! I've never seen a really reasonable and measured study of what commercial fusion might cost to produce power.

Indeed. Plus the thing about fusion power is that likely these plants will be absolutely massive, which raises issues about: * single point of failure * huge transmission needs * very large start-up cost, likely banning developing countries from using it.

All of these issues are much alleviated with distributed power like solar or wind (or the mini-reactors suggested by this article), which makes me think it's preferable.

One of the encouraging things about IEC fusion and dense plasma focus fusion is that they're supposed to be something you can do with smaller facilities, and construct incrementally. What you said certainly applies to more traditional fusion methods, though. We've already seen the economic problems of huge power plants with recent nuclear reactors: they're so darn big nowadays that financing them is a huge headache.

This is part of why I'm moderately excited about aneutronic fusion: the radiation damage you mention will be greatly lessened by reactions that release dramatically fewer neutrons.

As for the commercial cost of fusion, the reason you've never seen such a study is because nobody even knows yet how to get fusion to produce commercially usable amounts of power, and there are so many possible methods being looked at, with such different costs involved, that we can't really do a meaningful study of fusion economics yet.

I was working on aneutronic fusion for some time: my feeling is that there is a lot of research to go before we can know if it's even feasible; even then unless there are breakthroughs it will be difficult to do in small reactors. There are significant thermodynamic barriers to be overcome e.g. Todd Rider's thesis (I believe they can but they're difficult -- almost like no-go theorems for fusion).

As for whether one could do an economic study, I believe at least one could lower bound the cost, using the cost of the balance of the plant (steam generator, heat exchangers, cooling towers) and an expected cost and lifetime of the various structural and shielding materials.

Regarding #1 -- "educational capacity to train the people needed".

One of the additional benefits to source article's proposal: There's a large, highly trained base of Navy 'nukes' who are in the fleet now or out in the world. Many of the ex-nukes are building and operating non-nuke plants now. These are the folks who spent years (decades) training and operating the same scale of power plants in the proposal (on subs and surface ships).

While university nuke-e programs are light, there's no shortage of folks to build, manage and do the work.

Professor B. is on to something.

Regarding your first point, I believe the current dearth of programs is a function of lack of demand: When I was at Georgia Tech, we had a reactor on campus and still only had 3 Nuclear Engineering students.

There is demand from industry, but not from students. In my class at NCSU I was the only one; the years before and after there were less than 10.

It's still a small department at NCSU, but not that small (so I've been told). I know some guys graduating this year and looking at graduate opportunities.

OT: Hello fellow Wolfpack-er. I think there are a couple other NCSU grads on HN, too.

I'd rather see liquid flouride thorium reactors than fusion. They're much more viable (we've already got the tech - they had a working one back in the '60s), cheaper (we've got thousands of tons of thorium sitting buried in the desert ready to go), safer (meltdown-proof by design), don't contribute to proliferation (byproducts cannot be used to create nuclear weapons), and reduce waste (the waste is safe in tens of years instead of tens of thousands of years).

We still don't have a working man-made prototype for a fusion power reactor.

This is crazy. No one is doing anything about the commercial waste, and this fellow wants to bring military-trained engineers in to create more waste?

To this date there are tanks full of liquid waste at military sites that people are concerned about touching in any way, because no one knows what's inside them, and there's the possibility that disturbing the contents might create a fissile mass.

I've got a better idea. Stick the corps on cleanup and have them report back when finished.

[edit: Just to be clear, I don't argue from an uninformed position. I do have a BS in nuclear engineering.]

That is because of the fuel types used. The Navy is using cheap fuel from the weapons program, which provides more than enough power and fuel for their needs. However the cities would likely use a Thorium reactor, which can easily be made to not produce weaponizeable (sp?) byproducts. I refuse to believe that France can handle itself with fission plants and we cannot. We must not allow irrational fears to drive policy and we must stop the use of fossil fuels to provide the majority of our power.

I say gimmie a few hundred fission plants, a new electrical grid, and electric cars & trucks. Our greenhouse gas emissions will go way down and our geo-political strength will rise.

Oh, and it would provide a spark for nuclear studies in the US which could give us an edge in energy production. I would love if the wind would provide for all our power needs, but fission is a great transition method. Use it until we can get fusion or viable solar/wind/bio power.

There's a good argument out there that wind can be considerably less expensive than coal with good energy storage and good transmission.

http://www.stanford.edu/group/efmh/jacobson/energy.pdf

I haven't seen anything like that for nuclear.

In the US, nuclear power is already cheaper than coal because we get most of it from old plants that have already paid for their construction costs, so now we're just paying operating and maintenance costs. Now imagine how much the situation would improve with any of these way of decreasing nuclear costs (in order of increasing radicalness):

* Mass-production of modular conventional reactors, like China is gearing up to do with AP1000 plants.

* Mass-production of smaller fourth-generation reactors, such as pebble beds (again, China is doing this) or some of the various breeder reactors, like the Hyperion Power Module.

* The same as above, but with Brayton-cycle gas turbines instead of steam turbines. This leads to simplified reactors and higher thermodynamic efficiency and quite significantly lower costs.

* The same as above, and then you stick them on a boat. This lets you float them to wherever they're needed, and the sea-water handles their cooling needs without costly cooling towers, and they can provide water desalination with waste heat. A nuclear aircraft carrier is already providing large amounts of fresh water to Haiti, and other countries are having serious water problems, and would pay good money for this. More here:

http://finger-tree.blogspot.com/2009/11/floating-nuclear-pla...

* Liquid fluoride thorium reactors. I love LFTRs; they're so damn beautiful that I'd recommend having a look at them just to appreciate the cleverness. They can be made at any size, they're self-regulating, they can load-follow beautifully, they can use supercritical CO2 turbines for cooling, the waste is tiny and becomes safe after about 500 years, and the fuel supply is enormous.

But how do the costs of any of the above compare to the cost of building a wind turbine? Even taking the fuel and operations and maintenance cost to be free, how does one compare the capital cost against other renewables where you don't pay for fuel?

If you use a Brayton-cycle gas turbine for a nuclear reactor, for example, now heat exchange to the gas becomes the biggest issue. And even the most optimized gas peaker turbine plants cost $500/kw.

The capital costs per kilowatt of average power generation are surprisingly good for nuclear. I don't have time to look up the figures now (sorry) but last time I checked, wind was more expensive to build average capacity than nuclear, even when you compared the cost of just the wind turbines with the complete cost of nuke plants.

> If you use a Brayton-cycle gas turbine for a nuclear reactor, for example, now heat exchange to the gas becomes the biggest issue. And even the most optimized gas peaker turbine plants cost $500/kw.

Heat exchange to the gas is an issue, but it's the sort of issue that nuclear reactor designers have a lot of experience solving. The Chinese pebble bed reactors, for example, are cooled with helium gas, and they don't seem to have much trouble with that.

As for the cost of the turbines themselves, in general Brayton-cycle gas turbines are cheaper than steam turbines, and supercritical CO2 gas turbines are remarkably small, so they'll probably be cheaper than the conventional ones. Even conventional gas turbines would work, though.

Of course, when competing with natural gas burners, the fuel cost is a huge issue. Natural gas fuel costs are vastly higher than those of nuclear plants (per kilowatt-hour, of course).

I'm not sure I answered what you were saying, but I hope I covered something interesting.

Prof. Marc Jacobson of Stanford pegs the cost of wind power at an amortized cost of wind at 3 - 4 cents per kwhr. There are independent indications that they're around 3.5 - 4 cents per kwhr. Nuclear can compete with that? Last I checked it was around 12 - 20 cents per kwhr...

http://www.stanford.edu/group/efmh/jacobson/energy.pdf

I wholly agree that, where feasible, wind and other renewable energy sources can and should be employed in preference to non-renewable sources. That said, as far as I understand, there are cases where such renewable energy sources are not feasible solutions, and in those cases, I think that we should prefer nuclear power to coal, diesel or any other fossil fuel power.

I can think of only four: naval craft, spacecraft, remote locations (e.g. antarctic) and when you need a neutron flux for some reason.

What are the others?

(This is intermittent renewables, wind+solar, with inexpensive and efficient energy storage. I agree if you don't have energy storage you're capacity limited.)

I was actually thinking of cases in which storage is limited, or in places where, for instance, that tend to get less wind. As for the energy storage issue, while storage technology has gotten much, much better, I don't think we're yet where we need to be to completely move over to pure renewable. I admit, though, that I am not an expert in energy storage, so I could be totally off on this.

All else aside though, wherever there is a choice between technologies such as coal and technologies such as nuclear energy, I think that the latter needs to be very seriously considered.

Energy storage isn't currently viable economically, but, speaking as the cofounder of a startup in energy storage, soon will be :-p

I'd like to point out that cheap energy storage actually improves the economics of nuclear power, by leveling the power demand, so they can productively produce power all the time, and hopefully replace natural gas for peak power.

Absolutely. However, storage helps intermittent and unpredictable variation more.

Well, there are problems with only relying on renewable power sources. Weather patterns change. At a glance, it would make sense to build smart a nuclear grid, then integrate distributed renewable power and storage options as appropriate. That gives the grid excellent redundancy and starts working on the current problems immediately while providing breathing room for the renewables.

The nuclear plants could then be used as backups and power government supercomputers when not needed (or something).

And, on the side, how about a Manhattan-style project to produce a commerical scale Thorium Reactor within five years?

Oak Ridge had a thorium reactor running for 5 years in the 1960's. I think it would be very feasible, especially since Canada is helping China with nuclear power plants. Thorium is also enormously more abundant and more evenly spread out over the world.

My point is that there's quite enough work already for such a corps. Weaponizeable (also sp?) or not, the idea of producing waste of such longevity and claiming that it is actually a solution is mind-bogglingly arrogant.

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