Nuclear Supercharged Gas Turbine Generator

!:,. (as pronounced by Victor Borge).

Hmmm.... no sir, I don't like it.

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A nuclear power plant that also pays for and burns hydrocarbons.

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A fossil fuel power plant that also produces highly radioactive waste.

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A nuclear power plant with the added uncertainty of natural gas supply/pricing.

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A gas turbine with the benefit of NRC oversight.

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A nuclear power plant that requires continuous delivery of fuel.

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This seems like a design that stacks complexity/disadvantages in exchange for uncertain benefit.....of course, my perspective might be biased against seeing the truth of any suggested benefit to such a compromise.

Well that seems a bit weak....Let's list the stated positives...

I don't know who marked your comment off topic. It certainly isn't. I've offset the 'off topic' even though I don't consider your answer particularly good.

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However, the benefits stated in the promoting website are not reliable.

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Nuclear Fuel ....cannot melt. Really? Sublimation doesn't sound like a good option, and that is the only alternative to melting. All reactors are built with redundant cooling, these guys just think their idea is fool proof. That does not instill confidence.

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Spent Nuclear Fuel....Massive Decrease. On what basis? The basis of offsetting it with natural gas?

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Proliferation...Not Feasible. More like understanding ....not sufficient. This is a graphite moderated helium cooled reactor, it would be exceedingly easy to install a U238 blanket to breed plutonium....ta-da! Boom!

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Catastrophic Failures....Public Protected. Oh, if only previous designs had thought to build in redundancy.... I'm not sure which is more disconcerting, the hubris, or the lack of familiarity with previous designs.

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Okay that's 4 for 4. This write up of claimed benefits is silly. You were right to call out the weakness you sensed, only you were off in the direction. The remainder of the list has some pretty ridiculous claims. Did you honestly read with reasonable skepticism?

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Solar Eagle, I admire much of what you write, this however seems out of character for you. If someone were parroting a list of unsupported claimed benefits, you'd be one of the last people I'd expect it to be. You generally strike me as someone who doesn't believe something simply because it appears on the internet. I generally expect you would either vet the information yourself, or include disclaimers that you either don't feel qualified to, or don't have the necessary access to data to do so....

I came across this and was intrigued with the idea of supercharging a gas turbine....the rest of the idea does look amateurish and not particularly well thought out....but I thought I'd put it out there for scrutiny.....found this company that is making gas turbine superchargers....

http://www.powerphasellc.com/1st-turbophase-unit-completed-ahead-of-schedule/

I did those, because I do care.

How was what he wrote 'off topic'?

I appreciate you creating the post. I was just taken aback by your initial defense of the concept.

Oh sorry, no I was putting some more ammunition out there.....this is from their website....creating a target rich environment as it were.....but you haven't commented on the supercharger concept....?

The supercharger concept looks very intriguing. I haven't gone over it in depth, but they seem to have done a good job at recuperating some previously lost heat and improving efficiency across varied operating conditions by decoupling the compressor from the main turbine.

It looks promising. I also think it is very different in important ways from the hybrid nuclear-gas turbine concept in the OP. The group developing the supercharger is not like the group suggesting the nuclear-gas hybrid....at least that is the impression I get.

Once again, I find myself asking 'How is the previous comment 'off-topic' by any reasonably evaluation'?

The previous comment is exactly on topic, just as the one to which it is a response.

I could understand if it had been rated a 'good-answer' and you happened to disagree vehemently , and so chose to counter the 'good-answer' rating, but that isn't the case.

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I suggest the addition of a system by which comment ratings are no longer anonymous. If we are going to allow people to make comments that they wouldn't make under their regular associated screen name, we should at least improve the quality of the rating system by having people own the ratings they give. Not only would it diminish the childish games played, it would make the rating more informative, as certain people's opinions of what is a 'good answer' or 'off topic' certainly carries different wieght and also has at least slightly different meaning.

You make an excellent point about the helium. Helium is like Houdini: there is no container on Earth that will contain helium for very long. You can slow down the leakage but you cannot stop it entirely. It WILL leak out. The question is not one of "if" but of "how soon?"

Another thing about that design: why must that air compressor be *inside* the containment vessel when only the drive shaft need penetrate through the vessel wall? Lots of opportunity for containment failure there.

I don't like it one bit.

Offhand I'd say that makes about as much sense as harnessing a team of horses to a Lamborghini - with the Lamborghini out front.

Especially a team of 10,000 horses.

One thing I've wondered about for some time: nuclear power plants create lots of 'hot' nuclear waste whose storage is a big and growing problem. It is not only hot in the radiological sense but also produces a great deal of heat; heat which has thus far been completely wasted. Why not use this heat to drive organic-cycle Rankine turbines?

OCRTs use working fluids which have a much lower boiling point than water and are often used in conjunction with solar ponds to drive generators. Why not use the heat from nuclear waste to do the same? Is this being done anywhere?

I've been wondering the same thing for years....In fact I don't see why nuclear power plants aren't all ORC with efficient heat exchanger fluids operating at much lower temperatures, requiring much less fuel, and lasting much longer....

A 'hidden plus' in the making use of this heat from nuclear waste is that people will keep a much closer eye on it rather than do what they've done in the past: entomb it concrete and chuck it in the ocean, or bury it in underground tanks which will eventually leak and most likely when nobody's looking, etc.

Even if we stopped producing this waste today, we have plenty on hand already from which we could generate power til the cows come home, so why not?

It is probably deemed not economically viable due to the combination of insufficiently concentrated heat source and high expense to meet NRC requirements for containment.

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Heat produced from each of the various isotopes decays exponentially, but the overall decay heat isn't a simple exponential decay. Various half life times, decay chains, and different decay modes make modeling decay heat more complex. To add to the complication, reactor power prior to shut down also effects decay heat.

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That said, you can understand the barriers to competitive power generation using the reasonable rule of thumb one ton of spent fuel produces around 10 KW of heat roughly 1 year from shut down. Assuming average power at one year out isn't as conservative as it might first appear. That necessitates a fairly high turnover rate, for an evolution that is fairly risky. Assuming a wholesale electricity price off 0.15 $/ KWhr ...just a guess. and lets be very generous and assume overall 83.3333% efficiency for quick numbers. That yields 30$ per day per ton for high efficiency, high price, and 100% utilization.

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To make use of that 10KW of heat per ton, you have to deal with some very intense high energy radiation from some fission product decay daughters that aren't all conveniently solid at the probable temperatures. The cladding will have been significantly impacted by its previous exposure to intense neutron flux, so the flow off coolant needed to make use of the decay heat has the potential for opening quite an unfriendly can of worms.

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Adding in the amortized expense to construct the primary and secondary (contaminating the turbine would probably be very expensive long term), containment, shielding, turbine, generator, filtration and exchange resin, pumps, design, insurance, and expense approval; along with the energy to run the pumps, the money to pay the staff, maintain licensing, remember maintenance on radioactive systems is going to be more expensive, and the probably necessary PR expenses; I suspect the prospects for breaking even are so remote, it would be only something our government would possibly consider.

They've already got underground tanks of nuclear waste which has been boiling away for decades and expected to continue doing so for hundreds if not thousands of years. I don't know what is in those tanks, whether spent fuel rods or something else, but one thing is certain: that ain't no paltry 10 kW/ton boiling in those tanks.

Another thing: two identical chunks of fissile material which individually produce X amount of heat do not necessary produce 2X amount of heat when brought together. This fact was conclusively demonstrated in Alamagordo, New Mexico, on July 16, 1945.

The spend fuel in pools is not intended to stay there for thousands of years. The heat does indeed decay rather quickly and 10KW per ton at one year out is a good figure for most spent fuel. If you disagree, please provide some backing or a counter reference, otherwise the only thing that might reasonably be called paltry would be your argument.

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In the second paragraph, you are confusing decay heat with fission. Spend fuel is not kept in arrangements that lend themselves to criticality. Without criticality the addition to heat from fission is limited to spontaneous fission and has nothing to so with proximity. If you plan to use the spent fuel in an arrangement in the hopes of regaining criticality, you have a whole slew of new problems.

I said I don't know what's in those tanks, whether fuel rods or not.

you are speaking of tanks at Hanford I presume? those have liquid waste left over from plutonium production and separation. they are solvents that are contaminated with transuranic elements, some have relatively short half lives, some quite long. I read an article a month or so ago on what is in those tanks and what is being done about them. Here is a link:

http://www.forbes.com/sites/jeffmcmahon/2012/08/27/whats-inside-the-suspect-nuclear-waste-tank-at-hanford/

I am not confusing anything. Moreover, as I said, I don't know what's in those tanks, whether fuel rods or not. Read it again.

I'm sorry TINAC but, quite honestly I would prefer not to engage you in conversation. I don't mean to sound harsh, but your ability to misconstrue others' comments is nothing short of astonishing and, if that weren't enough, you then inevitably make it personal. And yes, my comment here IS personal because it has to be; I am addressing you, not spent fuel rods.

I don't mean to be impolite, but conversing with you is about as joyful as slogging through thick mud on a rainy night, and it seldom edifies. You say you value the truth? Well, there you have it: The Truth.

Please do not engage me further in conversation; I will not respond.

Thanks.

You certainly have the right not to respond. If that is your preference. That is exactly what you should do.

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I was responding to your musing about why spent fuel is not used to generate power. I provided a reasonable explanation (complete with a reference for the one assumption) to that open musing.

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After suggesting that the one assumption was not reasonable, you now seem quite irritated. I'm sorry that you feel so upset. It isn't my fault that your idea is highly unlikely to be economically viable, I'm merely pointing out that reality.

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By the way, spent fuel is exactly what is kept in the spent fuel pools. The duration is on the order of ten years.....not thousands. Those thousand year boiling pools, to the best of my knowledge are unknown in this world, and exist only in places like your imagination.

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Feel free not to respond or not respond. You might also take a moment to realize you are also free to divest your personal feelings from any particular point you might be experimenting with. I will continue to comment on subjects that I know something about, and it will probably cause you less stress if you realize that when I oppose certain assertions, that I am not opposing you personally, even if you are the one who made the assertion.

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P.S. If ever I hear the words "I'm not confusing anything" coming from my mouth (or see them appear in something I am typing) I hope it sets off alarm bells in my head. It should be a strong warning to review my assumptions.

Well I wasn't suggesting that the pools be used as a heat source, that certainly wouldn't work....The spent fuel rods would require some reprocessing, but are certainly a viable source of heat.....

Indeed. There is significant fuel in spent fuel and reprocessing could be very beneficial. The main thing standing in the way has been politicians devoted to demonstrating the law of unintended consequences.

I'd really like to see the US get back on track with reprocessing.

I don't like this idea one bit, I just don't get the point of this design. I believe that molten salt SMR one 25 MW reactor module buried every 10 square miles. Gen4 energy finally received there advanced reactor R&D grant from the DOE for there advanced reactors that utilize a lead bismuth coolant.

Fast reactors, like the one in your Reactor Block make nice breeders and have been in development for quite some time.

Note: That guy needs to grammar check his web site, though.

Adding another system off of the end to utilize the waste heat and pressure seems like a no brainer. A diesel engine (meeting minimums) without a turbo is a waste of energy, too.

The trouble would be meeting regulatory wickets from the federal and state authorities and the coordination which would result. It's hard enough for existing energy plants to meet those requirements from time to time.

We're smart enough to do it, but dumb enough to screw it up, too.

Although it does resemble a fast reactor at first glance, the material notes use of a graphite moderator. Inclusion of a moderator indicates operation in the thermal neutron region.

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Technology to utilize waste heat and pressure definitely makes sense, but in this design, it appears the nuclear power is only used to turn the decoupled compressor, so it isn't use of waste heat/pressure so much as the only use.

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Your insight into regulatory entanglements is dead on.

looks like a solution in search of a problem if you ask me. why not use a Rankine or Brayton cycle? you don't need to burn Natural Gas then.