[HN Gopher] I'm in Wyoming to celebrate the next nuclear breakth...
___________________________________________________________________
I'm in Wyoming to celebrate the next nuclear breakthrough
Author : erentz
Score : 274 points
Date : 2023-05-06 05:43 UTC (17 hours ago)
(HTM) web link (www.gatesnotes.com)
(TXT) w3m dump (www.gatesnotes.com)
| barathr wrote:
| The lifecycle cost of nuclear is still higher than solar PV _even
| with storage_ and we have low-risk, low-tech solar-with-storage
| options such as molten-salt concentrated solar, which, while not
| as efficient as solar PV, is very simple technology.
|
| Solar PV and wind are cheap enough that overbuilding is easy. One
| might wonder what we can do with surplus power during times of
| day when we have too much solar (middle of the day) or too much
| wind (middle of the night) -- we can do desalination with the
| surplus solar (matches the demand curve of water use across the
| day and across the year) and convert wind to nitrogen:
|
| https://wcroc.cfans.umn.edu/research/renewable-energy/wind-f...
| albertopv wrote:
| For solar and wind you need TWh of storage capacity, in Europe
| many days without solar or wind (just bad weather) is
| relatively common.
| tuukkah wrote:
| Existing hydro is able to fill in for some of the storage
| needs, and pumping water up the dam will be one type of
| large-scale storage that can be built. See pumped-storage
| hydroelectricity: https://en.wikipedia.org/wiki/Pumped-
| storage_hydroelectricit...
| tuukkah wrote:
| To get an idea of the scale of hydro storage:
|
| > _European hydropower reservoirs provide a storage
| capacity of 220 TWh (85 TWh are located in Norway)._
|
| https://setis.ec.europa.eu/hydropower-and-pumped-
| hydropower-...
| ren_engineer wrote:
| >solar
|
| I love the idea of being completely reliant on something where
| China controls 80% of the supply chain -
| https://www.iea.org/reports/solar-pv-global-supply-chains/ex...
|
| Surely nothing could go wrong there, it's not like Russia
| pulled the same strategy and funded anti-nuclear activists in
| Germany to get them dependent on Russian natural gas.
|
| >wind
|
| I've talked to executives at energy companies who said they
| only built wind due to the massive subsidies. There's also
| major issues with what to do with the windmill husks once they
| are decommissioned and the fact they are a massive eye sore.
|
| If the US was serious they'd spin out some of the US Navy's
| reactor tech and turn all that technology into a profit center.
| They could even do a "bases for reactors" program where nations
| get electricity in return for allowing the US to operate the
| reactors on their land
|
| https://en.wikipedia.org/wiki/Destroyers-for-bases_deal
| tuukkah wrote:
| Buying solar panels from China is not the same kind of
| dependency as buying fossil fuels from Russia: the first is
| an investment, the latter is consumption. Also, solar panels
| can be built anywhere, while fossil fuels are a limited
| natural resource with no deposits in e.g. Germany.
| hedora wrote:
| What solar storage technologies work in the winter? For
| instance, it has been rainy in California this year, and
| between Jan and March, we were at a production deficit of 1MWh
| for our house. So far, in May (so the last 5 days) we're at a
| 275KWh deficit, and every day has seen a deficit so far.
|
| I'd love to have a 1MWh battery, but current raw battery cost
| is $151/KWh, and actual residential systems are closer to $333
| to $666 / KWh installed. At the raw battery cost (ignoring
| space requirements!), we'd have already burned through $41,000
| of battery capacity this month, and the weather forecast
| suggests we'd need double of that to get through till
| wednesday. That's $82K for raw batteries, or $275K at the
| midrange for residential installs (ignoring solar costs). Grid-
| scale storage is somewhere between those two numbers, and this
| is May. Winter this year was even more unworkable.
| tuukkah wrote:
| Small-scale solar installations are not supposed to get you
| off-grid and like you observe, a small-scale/battery storage
| isn't going to change that.
|
| Instead, the idea is the grid-scale combination of solar,
| wind and hydro with various storage and adaptive consumption
| solutions. For example: when water levels are down, pump
| water up the dam during sunny/windy hours to store energy for
| the bad months.
| JumpinJack_Cash wrote:
| > > is very simple technology
|
| AKA it won't bring about the next industrial revolution. It
| will maybe secure a world where the Earth is 0.01 C cooler vis-
| a-vis fossil fuels.
|
| Nuclear is exciting because humans can play God, that's where
| innovation lies, containing the power of the cosmos in a human
| friendly manner. With all due respect people who love
| renewables are un-imaginative and they resigned themselves to
| technological stasis in exchange for a reduction in CO2
| emissions. That's a very underwhelming proposition, because in
| short, it means that there is nothing for us, but only benefits
| for maybe those who'd be alive in 200 years. That's
| unacceptable and un-American.
|
| This initiative is to be encouraged and Mr. Gates has a history
| of being the person who had the privilege of signing off huge
| quality of life improvements for Americans . Which is mostly
| luck among those who had the right vision, in Windows case the
| GUI. But still it's something, I believe that other GUI
| pioneers would be financing the same projects had they been the
| ones ending up with a 200bn net worth.
| StillBored wrote:
| Its very tiring that there is always someone here telling us
| how inexpensive PV and wind are compared to other generation.
| Which is true per watt, until you try to assure that watt is
| actually available when its needed.
|
| So its comparing the costs of two entirely different things,
| power which can be predicted and produced at a given level, and
| power which may or may not produce anything over a given time-
| frame. And so, i might say its a lie...
|
| Particularly because the costs associated with making a watt of
| wind/PV reliable easily adds an order of magnitude in costs,
| making wind/PV a much worst cost proposition than just about
| anything else. And its particularly bad in places that don't
| have existing hydro and nukes because the only realistic way to
| back it up with today's technology/economy is fossil fuel
| sources. (aka grid scale batteries capable of multi day power
| storage simply don't exist, and you can't "overbuild" your way
| out of the problem.). So its not even carbon free.
| ZeroGravitas wrote:
| The comment you replied to explicitly addressed how to make
| cheap renewables more available.
|
| You might disagree, but acting like they never even mentioned
| it makes it seem more likely that you're just going on
| outdated info.
| belorn wrote:
| The storage in "PV with storage" is most commonly measured
| in single digit hours of capacity, and is primarily used in
| locations where the sun is predictable up during the day
| and has a predictable discharge/charging cycle of 24 hours.
| One of the biggest upside is that the economics of it is
| fairly simplistic with 365 cycles each year that produce
| predictable revenue.
|
| There is a second form of storage that is also fairly
| common, which is storage that exist to balance the grid
| when different units goes up and down. Those generally have
| even less capacity and are not intended to operate under
| long periods.
|
| For locations where the first form of PV with storage
| works, they should really replace everything (with imports
| handling any exceptional weather events). Storage of this
| form does however become significant more expensive the
| further away we get from this optimal weather pattern, and
| there is a multiple reasons why wind heavy nations can not
| survive on a few hours of storage. Latitude and seasons can
| also have a very large impact if a nation where to use this
| as their only strategy.
| pydry wrote:
| >Its very tiring that there is always someone here telling us
| how inexpensive PV and wind are compared to other generation.
| Which is true per watt, until you try to assure that watt is
| actually available when its needed.
|
| It's 5x cheaper per watt. That goes up to 1.5-3x cheaper once
| you add "when needed".
|
| OP already mentioned that it is cheaper with storage. You
| ignored them.
|
| >Particularly because the costs associated with making a watt
| of wind/PV reliable easily adds an order of magnitude in
| costs
|
| An order of magnitude is absurd.
| coyotespike wrote:
| Let's champion both.
|
| Living in Austin, I plan to add solar to my house someday,
| and I would also love to see us build nuclear power plants.
|
| I really cannot understand why people set these things at
| odds with each other. They are both better than fossil fuels
| or degrowth.
| derefr wrote:
| > I really cannot understand why people set these things at
| odds with each other. They are both better than fossil
| fuels or degrowth.
|
| Mostly because in many places nuclear power is currently
| politically blocked from any further build-out, if not
| outright banned. One of the main rhetorical moves that
| various "green" (i.e. anti-nuclear) lobbies say to justify
| not building out nuclear power -- which regulators seem to
| have absorbed and now believe -- is "for everything we'd
| use nuclear for, we can just use PV."
|
| This statement has a clear refutation: nuclear is base-load
| + grid-scale, while PV elastic-load + individual-site-
| scale; so if you need to e.g. double the electrical
| capacity of _a large city_ in response to population
| growth, then PV isn 't going to work--you want nuclear (or
| another base-load grid-scale power technology, like
| hydropower.)
|
| But these arguments don't get heard; rather, the regulators
| say "but we have PV, what's the point in building nuclear
| rather than just supporting the build-out of more PV?" as a
| conversation-ending rhetorical statement.
|
| In order to convince regulators to allow the build-out of
| nuclear, there has to be some equally-powerful rhetorical
| statement that can be used to "reopen the conversation."
| Which would, intuitively, come in the form of a clear and
| effective condemnation of PV as a base-load / grid-scale
| power technology. But if regulators don't _understand_
| terms like "base-load" or "grid-scale", then what you end
| up having to do to get them to stop packing up and shooing
| you out of the room, is to condemn PV full-stop.
| whitemary wrote:
| Because financialized/late-stage capitalism makes long-term
| investments like nuclear power generation financially
| infeasible, while funneling subsidies to "green energy"
| solar/wind industries is extremely profitable in the short-
| term.
|
| In other words, the thing that actually works is
| significantly less likely to happen, and therefore requires
| far more support.
| loeg wrote:
| They don't have especially complementary profiles for a
| generation mix, unfortunately. So at scale it seems like
| you have to pick one or the other.
| ZeroGravitas wrote:
| I don't think it makes financial sense to build new
| nuclear, but solar and nuclear pair reasonably well if
| you have existing nuclear, at least in areas where air-
| con is used (demand peaks in summer afternoons).
|
| The problem only arises when you don't charge coal and
| gas plants sufficient carbon/pollution fees, then they
| can underbid nuclear and drive it out of the market and
| stop it earning enough overnight.
|
| to quote the nuclear industry:
|
| https://www.theguardian.com/australia-
| news/2019/jun/04/nucle...
|
| > Nuclear could provide cheap energy but would only be
| competitive with gas and coal if carbon pollution is
| priced, nuclear association says
| pydry wrote:
| >I really cannot understand why people set these things at
| odds with each other.
|
| Because they compete for investment dollars from the
| government.
|
| Why doesnt the government just fund the cheapest one?
|
| Because the nuclear military industrial complex needs a
| civilian nuclear industry to operate cost effectively.
| skybrian wrote:
| I'm wondering what kinds of reliability we actually need.
|
| Residential: it seems like we often accept less reliability?
| It's common for bad weather like thunderstorms to cause power
| outages, particularly in rural areas. Lots of places in
| California will get cut off during high winds.
|
| If you need reliability, a battery backup protects you from
| more outages, including those that take out the grid. In some
| cases a generator makes sense (such as for a data center),
| but it's higher maintenance.
| tuukkah wrote:
| Yes, all the cheap surplus wind and solar power will be used
| for many things, also e.g. low-emission production of steel and
| hydrogen, running heat pumps and even boiling water for hot
| water reservoirs etc.
|
| Also, this "nuclear breakthrough" concept is likewise
| complicated by storage:
|
| > _It also includes an energy storage system that will allow it
| to control how much electricity it produces at any given time._
|
| Why do they have to complicate it? Otherwise, they wouldn't
| have a chance competing with the cheap price of renewables:
|
| > _it's essential for integrating with power grids that use
| variable sources like solar and wind._
|
| Basically, nuclear plants generate losses when it's sunny or
| windy, and profits from the dark and calm times won't make up
| for the losses. (The flexible power consumption will switch off
| rather than pay the higher nuclear power prices.)
| [deleted]
| TradingPlaces wrote:
| It's much more expensive than solar or wind + storage, so why
| exactly?
| danmaz74 wrote:
| More expensive than "solar or wind +" which amount of storage?
| The amount of storage which would put wind/solar on par with
| nuclear in terms of reliable baseload is huge.
| crims0n wrote:
| More reliable, less of an eyesore.
| hermitcrab wrote:
| I think windmills are rather beautiful. Subjective,
| obviously.
| ren_engineer wrote:
| Have you ever been around a sizable wind farm at night when
| you have to look at bright red flashing lights for miles in
| every direction?
| hermitcrab wrote:
| Can't say I have. Is it any worse than looking out at a
| big city at night?
| Zigurd wrote:
| Exactly. Electricity is fungible and so is capital. Spend the
| capital on the technology that arrives soonest with the least
| capital.
|
| Cost comparisons for nuclear are also dubious. The French are
| discovering their decommissioning costs are a multiple of what
| they predicted. Who, using what cash-generating capability, is
| going to pay for that?
|
| And where to reprocess or stash the waste?
|
| What we are seeing with uranium fission plants being touted as
| new tech is an attempt to forget the PWR uranium fission
| problems. TBF it is not for the sodium-cooled uranium reactor
| people to solve _all_ the problems. But those problems still
| need solving.
| FredPret wrote:
| No it isn't. Electricity has to be delivered the instant it
| is consumed. You can pile up capital.
| Zigurd wrote:
| Storage in the form of batteries, pumped storage, hydrogen,
| or ammonia works. It is needed more for renewables than for
| nuclear, but nuclear is hard to throttle to a fine
| granularity like fossil fuel plants.
|
| Anyway, I should have said power generating capacity is
| _mostly_ fungible. You can _mostly_ replace any capacity
| with a different kind, within some limits, the same way
| money isn 't perfectly fungible if you need currency
| conversion, have FDI limits, repatriation limits, etc.
| FredPret wrote:
| So a reasonable engineer would then conclude the
| practical route to a green grid is nuclear baseload +
| natural gas peaking + solar and windmills.
|
| Storage is nowhere near practical today. A house can
| barely run off batteries. How about mines, factories,
| aluminum smelters.
|
| In future it would be great if this changed.
| acidburnNSA wrote:
| That statement is being challenged.
|
| https://www.ctvc.co/firming-costs-renewables/
| wolverine876 wrote:
| How hard would it be to use all the heat to generate usable
| energy, rather than discarding a bunch of it via coolant? I don't
| know much about nuclear reactors and I'm sure I'm not the first
| to think of it, and I'd guess it's quite a bit of heat - but then
| it's quite a bit of usable energy.
| RhodesianHunter wrote:
| That's exactly what it's doing.
|
| The problem is not getting rid of excess heat, it's that the
| heat causes wear and maintenance issues due to pressure, needed
| pumping, etc.
| ZeroGravitas wrote:
| He's still talking down renewables, which is unfortunate, but we
| got to the tipping point despite him so it's less annoying than
| it used to be.
|
| > fact, in terms of lives lost, nuclear power is by far the
| safest way to produce energy.
|
| I don't think this is true anymore even if you skip the "by far"
| and if you include the "by far" it's not been true for maybe as
| long as this plant has been in planning.
| Drblessing wrote:
| > I don't think this is true anymore even if you skip the "by
| far" and if you include the "by far" it's not been true for
| maybe as long as this plant has been in planning.
|
| Source?
|
| https://www.sciencedirect.com/science/article/abs/pii/S22113...
| ZeroGravitas wrote:
| https://ourworldindata.org/safest-sources-of-energy
|
| This is a pro-nuclear site. The original version of the
| article had nuclear coming out but had no info on renewables:
|
| https://web.archive.org/web/20200210102743/https://ourworldi.
| ..
|
| They updated it with newer information, and now it is no
| longer winning.
|
| That "new" information, is from 2014, from this paper:
|
| https://www.sciencedirect.com/science/article/abs/pii/S09596.
| ..
|
| > Our study shows how these energy systems collectively
| involved 686 accidents resulting in 182,794 human fatalities
| and $265.1 billion in property damages. Across the entire
| sample, the mean amount of property damage was $388.8 million
| and 267.2 fatalities per accident, though when reflected as a
| median the numbers substantially improve to $820,000 in
| damages per accident and zero fatalities. Wind energy is the
| most frequent to incur an accident within our sample (48.8
| percent of accidents), hydroelectric accidents tend to be the
| most fatal (97.2 percent of all deaths), and nuclear energy
| accidents tend to be the most expensive (accounting for 90.8
| percent of damages). The article uses this data to present a
| set of unique risk profiles: nuclear, hydro, and wind energy
| are categorized as having a "high" risk of accidents;
| hydrogen, biofuels, and biomass "moderate" a accident risk;
| solar and geothermal a "low" risk.
|
| Think about how much renewables have been deployed since
| 2014.
|
| https://ourworldindata.org/grapher/modern-renewable-
| prod?tim...
| barney54 wrote:
| So when will Terra Power actually begin construction? What really
| matters is that these small modular reactors actually get built.
| ddgflorida wrote:
| Right - quite surprising how long it takes to get one of these
| up and running.
| Jabbles wrote:
| _" liquid sodium, whose boiling point is more than 8 times higher
| than water's"_
|
| Ew, multiplicative temperature comparisons in unspecified units.
|
| Sodium's boiling point is 882'C.
|
| _" so it can absorb all the extra heat"_
|
| Confusion of temperature and heat? Sodium's specific heat
| capacity is ~1/3 of water, so sodium's higher boiling point
| doesn't by itself mean that it can absorb more heat, though ofc
| the combination is still in sodium's favour.
| pyrale wrote:
| The text also kind of blanks the part where 2/3rd of world's
| nuclear reactors are PWRs, with typical water boiling
| temperature around 275degc.
|
| Overall, the piece is a very flattering take on the technology,
| where all drawbacks are forgotten, and the comparison with
| competitors is not really honest.
| anonuser123456 wrote:
| I don't think the specific heat matters so much. The key is the
| boiling point is so high, the thermal flux will cool the system
| before pressurizing it. IIRC, thermal flux is proportional to
| the temperature differential.
| sandworm101 wrote:
| But sodium's reactive, fire-starting, go-boom, good pair of
| running shoes temperature is considerable lower than water's.
| sbaiddn wrote:
| His understanding appears worse than that. Heat capacity is
| important, but as a second order. Absolute temperatures is the
| real deal since it sets the Carnot efficiency.
|
| Another way to look at it, if I were doing a back of the
| envelop calculation (the most important calculations), I
| wouldn't look up the Cp of Na. Id only look up its boiling T
|
| High Cp, low Cp... that can be remedied to some extent by
| running the pump faster or slower.
| jebarker wrote:
| > Ew, multiplicative temperature comparisons in unspecified
| units
|
| In the previous paragraph he's said that water boils at 100 C
| [deleted]
| tempodox wrote:
| I'd expect a multiplicative temperature comparison to refer
| to Kelvin, not Celsius.
| [deleted]
| jebarker wrote:
| Ah, TIL that Celsius is "non-multiplicative". From ChatGPT:
|
| "When using Celsius as the unit for temperature, it is not
| meaningful to say that one temperature is a certain number
| of times higher than another. The Celsius scale is based on
| the freezing point (0degC) and boiling point (100degC) of
| water, which are not absolute values. Thus, the Celsius
| scale has negative values, and simply multiplying
| temperatures does not provide an accurate representation of
| relative differences.
|
| If you want to compare temperatures in a more meaningful
| way, you should use the Kelvin scale. The Kelvin scale is
| an absolute temperature scale, with its zero point (0 K)
| representing absolute zero. In this scale, it is
| appropriate to say that one temperature is a certain number
| of times higher than another because the scale starts at an
| absolute zero point. To convert Celsius temperatures to
| Kelvin, add 273.15 to the Celsius value. Once the
| temperatures are in Kelvin, you can then make meaningful
| comparisons using multiplication or division."
| _a_a_a_ wrote:
| Yeah, kelvin strictly speaking, but for reactors on earth
| (not in 3 kelvin outer space) with a baseline earth-
| ambient temperature, perhaps multiplicative C is valid,
| very approximately? I don't know, I guess I'm asking.
| ethbr0 wrote:
| Specifying "times" in Celsius is fine... as long as you
| stay either positive or negative.
|
| Implying that you can only specify multiples in Kelvin is
| being pedantic.
| petesergeant wrote:
| > Specifying "times" in Celsius is fine... as long as you
| stay either positive or negative
|
| 127C is twice as hot as -73C though
| hermitcrab wrote:
| <pedant>C is a measure of temperature, not heat.</pedant>
| jenadine wrote:
| It's a bit the same as with time, multiplication of the
| time of the day don't make much sense.
|
| I started the work at 1:20 pm, but my colleague started
| three times later, at 4pm.
| _Microft wrote:
| The Celsius scale is an "interval scale" while the Kelvin
| scale is a "ratio scale". One cannot take ratios of
| Celsius values as ratios are not even defined for that.
| https://en.wikipedia.org/wiki/Level_of_measurement
| sgjohnson wrote:
| But not really.
|
| 100degC times two is not 200degC.
|
| 100degC times two is 473degC
| ethbr0 wrote:
| Howso? If the conversion to Kelvin is additive (as
| opposed to something more complicated), and multiplying
| in Kelvin is fine, then how is multiplying effectively-
| unsigned in Celsius not fine?
| sgjohnson wrote:
| Ok, another example.
|
| Is 10degC 10 times as hot as 1degC?
|
| No.
|
| Multiplying kelvin is fine because kelvin is an absolute
| scale.
| _a_a_a_ wrote:
| > No.
|
| For a given baseline, perhaps yes?. Kelvin has its
| baseline inherent, for C you can pick what you like _if
| you 're clear about it_. Perhaps. (Edit: and using only
| positive or negative temps as pointed out above)
| ethbr0 wrote:
| Yes.
|
| Parent's spaghetti examples weren't the most
| illustrative.
|
| What I believe they're griping about is that "10degC does
| not have _10x as much heat_ as 1degC. "
|
| In actuality, "10degC has 10x the _difference in heat_
| that 1degC has _relative to the freezing point of water_.
| "
|
| So it's a comparison definition quirk, not a numerical
| one.
| yarg wrote:
| c = k + 273 x * c = x * k + x * 273
|
| This leaves multiplied celsius off by a delta of (x - 1)
| * 273.
| bo1024 wrote:
| Temperature, especially in this context, relates to
| energy. The relative energy isn't 8x.
|
| > boiling point is more than 8 times higher than water's,
| so it can absorb all the extra heat
|
| This is a bit like saying that a skyscraper is 8 times as
| tall as an apartment building, so the gravity is much
| weaker up there. Obviously not as extreme a mistake, but
| that's why people are jumping on it.
| hermitcrab wrote:
| Or Rankine for a US reactor, surely? ;0)
| DarkNova6 wrote:
| Sodium is such a nightmarish coolant. Yes, there are advantages
| in building and engineering a sodium cooled reactor, but from
| an operating point of view... oh boy.
|
| Sodium catches fire when exposed to air.
|
| Sodium reacts violently with water (used in some designs as
| secondary cooling cycle).
|
| Sodium absorbing a neutron creates a strong gamma emitter with
| a low half time.
|
| Sodium reactors have always had low availability times, caused
| by constant technical problems.
|
| However unlike lead as coolant, no advances in material
| sciences are required to get an operational Gen 4 reactor. On
| the upside, you can pretty much use Sodium (fast) reactors
| right now... but maybe you shouldn't?
| pookha wrote:
| "Sodium reacts violently with water (used in some designs as
| secondary cooling cycle)."
|
| Wow. This statement is ludicrous. It's like me saying this
| wind-turbine is dangerous because of solar-panel hazardous
| waste...Seemed pretty obvious (guy in the article goes on for
| a while talking about why water was a bad choice) that the
| design for this reactor is using some variation of molten-
| salt as a coolant (not pressurized water).
| jakewins wrote:
| This seems overly harsh - is there not water involved at
| the plant to drive the steam turbines?
|
| That the design of the plant does not directly heat water
| from sodium is great, but it still is useful to know the
| plant becomes sensitive to water issues like flooding.
| Iwan-Zotow wrote:
| > Sodium reactors have always had low availability times,
| caused by constant technical problems
|
| BN-800 has between 70 and 80%, looks good to me
| tremon wrote:
| Are you saying they use raw sodium as the coolant? I thought
| they used a sodium-based salt liquid? In which case, most of
| the sodium in the mixture is too tied up to react with air or
| water.
|
| (edit: yes they do, see
| https://news.ycombinator.com/item?id=35841237)
| juliennakache wrote:
| From a link shared in a thread below:
|
| "High-temperature properties such as the volumetric storage
| density, viscosity and transparency are similar to water at
| room temperature. The major advantages of molten salts are
| low costs, non-toxicity, non-flammability, high thermal
| stabilities and low vapor pressures. The low vapor pressure
| results in storage designs without pressurized tanks (Fig.
| 1). Molten salts are suitable both as heat storage medium and
| heat transfer fluid (HTF). In general, there is experience
| with molten salts in a number of industrial applications
| related to heat treatment, electrochemical treatment and heat
| transfer for decades."
|
| I don't know anything about this but it does seem that things
| are not as clear cut as your comment made it seem.
|
| ref:
| https://onlinelibrary.wiley.com/doi/10.1002/cite.202000137
|
| EDIT: From ChatGPT 3.5:
|
| " One of the most commonly used molten salts in nuclear
| reactors is a mixture of lithium fluoride (LiF) and beryllium
| fluoride (BeF2), commonly referred to as FLiBe. FLiBe is used
| as both a coolant and a neutron moderator in some types of
| nuclear reactors, such as molten salt reactors (MSRs) and
| some advanced small modular reactors (SMRs).
|
| FLiBe has several advantages as a coolant in nuclear
| reactors, including its good heat transfer properties and its
| ability to operate at high temperatures without evaporating.
| Additionally, FLiBe is not highly corrosive to many materials
| commonly used in reactor components, which can help reduce
| maintenance and replacement costs.
|
| However, FLiBe does have some potential disadvantages, such
| as its relatively high viscosity, which can make it more
| difficult to pump and circulate, and its high melting point,
| which can increase startup times for reactor systems.
| Additionally, FLiBe can be corrosive to some materials, such
| as aluminum and some types of steels, so care must be taken
| in selecting materials that are compatible with FLiBe."
| credit_guy wrote:
| The reactor that Gates talks about (Natrium) uses sodium as
| moderator and coolant. In other words, the uranium fuel is
| submerged in a pool (literally, a pool) of liquid sodium.
| There are some pipes that circulate the liquid (and very
| hot) sodium to a separate place, where it heats up a
| secondary circuit of molten salt. That molten salt then
| goes on to heat some water and make it steam, which then
| drives some turbines and generate electricity. Or that
| molten salt can be left molten for a number of hours, as
| some form of energy storage solution.
|
| So, the molten salt does not get in contact with the
| nuclear fuel in any way in this design.
|
| There are other designs where this happens, and especially,
| there are designs where the uranium (or thorium) is itself
| part of the molten salt. Even Gates's company, Terrapower,
| has such a design in the works. But the Natrium reactor is
| not that.
| gus_massa wrote:
| > _Sodium absorbing a neutron creates a strong gamma emitter
| with a low half time._
|
| Isn't that a feature? Is it 24Na that decays to 24Mg in 14
| hours? In case of an accident, you can run away for a week
| and it will magically disappear. You don't need a long term
| storage of the waste.
| hermitcrab wrote:
| A half-life of a few seconds and it will probably decay
| before it gets near a human.
|
| A half-life of thousands years and it will give out it's
| energy so slowly you will probably be more worried about
| it's toxicity (e.g. plutonium).
|
| The most dangerous ones are generally those that have half-
| lives of days or weeks. That is long enough to get into a
| human body and give out a lot of it's energy. The is
| particularly the case for elements that are readily
| absorbed by the human body (such as strontium which replace
| calcium IIRC).
|
| On that basis radioctivity from sodium probably isn't too
| much of a threat. I would be more worried about it's
| reactivity.
|
| (not an expert on this, but did consultancy for the nuclear
| industry some time ago)
| George83728 wrote:
| > _The most dangerous ones are generally those that have
| half-lives of days or weeks. That is long enough to get
| into a human body and give out a lot of it 's energy. The
| is particularly the case for elements that are readily
| absorbed by the human body (such as strontium which
| replace calcium IIRC)._
|
| You're mistaken, the most dangerous waste is that with
| half lives measured in decades, like cesium-137 or
| strontium-90 which both have half lives of about 30
| years. That 30 year half life means that it can take
| centuries for the waste to decay away to safe levels.
| More than hot enough to kill, and with the longevity to
| do so for several generations. Strontium-85 and
| strontium-89 half half lives measured in tens of days,
| but after a few years you don't have to worry about those
| anymore. It's the isotopes like strontium-90 that are the
| major concern.
| wolfram74 wrote:
| for that specific waste, the coolant in a water cooled
| reactor isn't a huge problem either. The things that are
| "complicated" are the fuel rods that some people refuse to
| be convinced we can bury in storage until reprocessing
| becomes necessary.
| credit_guy wrote:
| Actually this might be sodium's biggest advantage.
|
| Everyone knows that Uranium (or Plutonium) can sustain a
| chain reaction: when hit with a neutron, they split in 2 or
| 3 lighter atoms, and 2 or 3 new (and fast) neutrons. That
| can be used to produce a bomb, because the fission events
| grow exponentially. But it's not all that useful for a
| reactor, where you want the number of fission events per
| second to stay constant in time. Which means, on average,
| each out of the 2 or 3 neutrons produced in a fission
| event, exactly one will trigger another fission event, and
| the remaining 1 or 2 neutrons have to find some way to
| disappear. Roughly speaking they can be absorbed by: 1. by
| some heavy nucleus like uranium 2. some control rods 3.
| some neutron poison introduced in the reactor on purpose,
| such as boron, gadolinium or hafnium, 4. the moderator,
| like water, or sodium in this case, 5. the walls of the
| containment vessel.
|
| If you think of it, it's such a waste. Many of these
| options result in radioactive elements. Some result in
| material embrittlement.
|
| Given that, it may very well be that sodium could be the
| best option out there.
| [deleted]
| RC_ITR wrote:
| There's an argument to be made that we should do a much
| better job of directing those neutrons to make tritium,
| since fission isn't even something to discuss until we
| know how to make abundant tritium.
| credit_guy wrote:
| Yes. But fusion is not quite here yet. It's a difficult
| business proposition to store large quantities of tritium
| in the hope that you'll be able to sell to an operator of
| a fusion reactor three decades down the road (after about
| 80% of it has decayed).
|
| On the other hand, when fusion is ready for prime time,
| one could use liquid lithium in a reactor. Liquid lithium
| has quite a number of advantages over sodium: in that
| temperature range it has more specific heat capacity than
| any metal, higher even than water. It has excellent
| conductivity.
|
| And if it captures a neutron, it splits in helium and
| tritium plus energy. It could increase the energy
| production of a fission reactor by more than 5%. And you
| get that tritium for free, and ultra-rare helium-3 if you
| fancy some aneutronic fusion at some point.
| sbaiddn wrote:
| Run away where? To the next river basin? Na will dissolve
| into any moisture and be carried away by any moisture.
| meepmorp wrote:
| The advantage is 24Na's short (14.9 hour) half-life, not
| the lack of solubility in water. Half of the original
| radiation will be gone in 15 hours, and close to 90% in
| two days.
| sbaiddn wrote:
| I understand half life. My point moisture currents can
| spread water soluble things very far very quickly.
|
| Think of it this way, what happens if there's a
| catastrophic sodium leak? The winds carry it far and the
| Na gets into everything because it will be diluted into
| the wind's moisture. Won't you breath the radioactive Na
| from the air's moisture?
| meepmorp wrote:
| The point is that the leaked material stops being
| dangerous before it can get very far.
| flangola7 wrote:
| Two days of strong winds and storms and you've just
| dumped sieverts on most of the central US and Canada.
| meepmorp wrote:
| 2 days and ~90% of the original radiation is gone. 3 days
| and it's ~97%.
| credit_guy wrote:
| All of these are true.
|
| Sodium catches fire when exposed to air. That's why you don't
| expose it to air. Generally you fill the reactor with argon,
| which is an inert gas, and very heavy (dense) compared to
| air. Leaks can still happen, and the few sodium cooled plants
| around the world have all experienced them. But the fire the
| sodium catches when in contact with air is a very mild one.
| It's nothing like the violent reaction sodium has with water.
|
| Which brings up your next point, that sodium reacts with
| water. For some reason you said "in some designs [water is
| used] as secondary cooling cycle". Which makes me think you
| are fully aware that this particular design does not actually
| use water in its secondary cooling cycle, but rather molten
| salt (point mentioned by Gates in the article). It's a bit
| disingenuous of you to bring up this point (arguably the
| greatest negative point about sodium) when it is actually
| irrelevant in the reactor discussed here.
|
| Sodium absorbs a neutron and becomes a strong gamma emitter
| with a low half time. To be more precise, the half life of
| Na-24 is 15 days [1]. It decays in a stable isotope of
| Magnesium, which is not radioactive. Any leak will result in
| radioactivity that will naturally completely disappear after
| about one year.
|
| As for the "strong gamma rays" (all gamma rays are strong, by
| the way), they are contained in the containment vessel.
|
| Edit: the half life of Na24 is 15 hours, not 15 days. Even
| better.
|
| [1]
| https://en.wikipedia.org/wiki/Isotopes_of_sodium#Sodium-24
| pixl97 wrote:
| >But the fire the sodium catches when in contact with air
| is a very mild one. It's nothing like the violent reaction
| sodium has with water.
|
| Yep, and then someone will go and build the reactor beside
| the ocean and a tsunami will swap it, or by a river for its
| cooling waters, and oopsie a flood.
| hermitcrab wrote:
| Not many tsunamis in Wyoming.
| tracker1 wrote:
| Or Arizona, Texas and New Mexico with an even more dry
| climate than Wyoming. Although, water is becoming a much
| more serious issue in these regions given the influx of
| migration from other states over time. I still think that
| Nuclear + Water for Hydrogen as a general fuel storage
| for transportation is a better option than battery
| packs... Though would require more investment in water
| infrastructure and transport as well as desalinization.
| pyrale wrote:
| I'd be curious to know how that radioactive coolant is
| processed to filter out magnesium that is bound to
| accumulate over time.
| credit_guy wrote:
| Sodium has a melting point slightly below 100 degrees
| Celsius. Magnesium has a melting point of 650 Celsius. I
| don't know the exact temperature that sodium will have in
| the Natrium reactor, but in the French Phenix reactor it
| was about 560 Celsius. But that's the highest one. The
| temperature at the bottom of the sodium pool is most
| likely much lower. In any case, much, much lower than the
| "freezing" point of magnesium, which will particulate.
| So, I imagine it can be filtered by a sieve made of
| steel, not much different than the sieve in my kitchen to
| filter my tea.
| RF_Savage wrote:
| Won't the magnesium just dissolve in the sodium? I'd
| expect distilling the sodium or chemically processing it
| being a requirement for removing accumulated magnesium
| from the sodium coolant.
| riffic wrote:
| this process (neutron capture and decay) contributes to
| only a small amount of magnesium in the reactor coolant,
| as the probability of neutron capture by sodium-23 is
| relatively low compared to other reactions involving the
| reactor's fuel, coolant, and/or structural materials.
| thuuuomas wrote:
| It sounds like you're expecting ideal operating conditions
| indefinitely?
| robocat wrote:
| It sounds like you don't understand that engineering is
| compromises.
|
| As soon as you involve radiation, you have some severe
| compromises to make, and the choices of elements you can
| use are limited.
|
| Sodium is not chosen because of its dangers. Sodium was
| chosen despite the dangers, because the engineers very
| very carefully looked at other options and the other
| options were _worse_ for the needs of their design.
| https://xkcd.com/793/ and
| http://johnsalvatier.org/blog/2017/reality-has-a-
| surprising-... seem relevant.
|
| Something as seemingly safe as water can be as dangerous
| as molten Sodium. The following is an explanation of the
| Chernobyl accident, which in part was due to using water
| as a coolant: Efforts to increase the
| power to the level originally planned for the test were
| frustrated by a combination of xenon poisoning, reduced
| coolant void and graphite cooldown. Many of the control
| rods were withdrawn to compensate for these effects,
| resulting in a violation of the minimum operating
| reactivity margin (ORM, see Positive void coefficient
| section in the information page on RBMK Reactors) by
| 01:00 - although the operators may not have known this.
| At 01:03, the reactor was stabilised at about 200 MWt and
| it was decided that the test would be carried out at this
| power level. Calculations performed after the accident
| showed that the ORM at 01:22:30 was equal to eight manual
| control rods. The minimum permissible ORM stipulated in
| the operating procedures was 15 rods. The test commenced
| at 01:23:04; the turbine stop valves were closed and the
| four pumps powered by the slowing turbine started to run
| down. The slower flowrate, together with the entry to the
| core of slightly warmer feedwater, may have caused
| boiling (void formation) at the bottom of the core. This,
| along with xenon burnout, could have resulted in a
| runaway increase in power. An alternative view is that
| the power excursion was triggered by the insertion of the
| control rods after the scram button was pressed (at
| 01:23:40). At 01:23:43, the power excursion rate
| emergency protection system signals came on and power
| exceeded 530 MWt and continued to rise. Fuel elements
| ruptured, leading to increased steam generation, which in
| turn further increased power owing to the large positive
| void coefficient. Damage to even three or four fuel
| assemblies would have been enough to lead to the
| destruction of the reactor. The rupture of several fuel
| channels increased the pressure in the reactor to the
| extent that the 1000t reactor support plate became
| detached, consequently jamming the control rods, which
| were only halfway down by that time. As the channel pipes
| began to rupture, mass steam generation occurred as a
| result of depressurisation of the reactor cooling
| circuit. Two explosions were reported, the first being
| the initial steam explosion, followed two or three
| seconds later by a second explosion, possibly from the
| build-up of hydrogen due to zirconium-steam reactions.
|
| https://world-nuclear.org/information-library/safety-and-
| sec...
| credit_guy wrote:
| No. But I have a hope that the US engineers can do at
| least as well as the Russian ones. Russia has been
| running BN-600 for more than 4 decades now, and BN-800
| for 8 years. There were incidents but not huge. Here's
| what wikipedia has to say [1] In the
| first 15 years of operation, there have been 12 incidents
| involving sodium/water interactions from tube breaks in
| the steam generators, a sodium-air oxidation/"fire" from
| a leak in an auxiliary system, and a sodium "fire" from a
| leak in a secondary coolant loop while shut down. All
| these incidents were classified at the lowest level on
| the International Nuclear Event Scale, and none of the
| events prevented restarting operation of the facility
| after repairs. As of 1997, there had been 27 sodium
| leaks, 14 of which resulted in sodium-air
| oxidations/"fires". The steam generators are separated in
| modules so they can be repaired without shutting down the
| reactor. As of 2020, the cumulative "energy Availability
| factor" calculated up to year 2019 and recorded by the
| IAEA was 75.6%.
|
| [1] https://en.wikipedia.org/wiki/BN-600_reactor
| [deleted]
| RC_ITR wrote:
| Water bombarded with neutrons create tritium, which is it's
| own nightmare.
|
| The problem is the neutrons, not what they hit.
| rvnx wrote:
| A higher boiling point means that the coolant can absorb more
| heat without turning into a gas, which is crucial for efficient
| heat transfer in the reactor.
|
| The statement about the boiling point being "8 times higher"
| refers to the boiling point comparison, not the specific heat
| capacity (which is +/- 3.4 times higher).
| Gwypaas wrote:
| Here is a read on the horror of building a sodium cooled
| reactor. Makes Vogtle look like a walk in the park.
|
| https://en.wikipedia.org/wiki/Monju_Nuclear_Power_Plant
| natmaka wrote:
| After bout 60 years and many heavily-financed large projects
| there isn't a single one industrial breeder reactor ready for
| deployment.
|
| https://en.wikipedia.org/wiki/Breeder_reactor#Development_an.
| ..
| Mistletoe wrote:
| >As of June 2011, the reactor had only generated electricity
| for one hour since its first testing two decades prior.
|
| It would be hilarious if not for the wasting of a trillion
| Yen on this.
| can16358p wrote:
| Continuosly talking about providing workers and patriotically
| pumping US's independence on power, while only slightly touching
| the actual plant design and safety with questionable points.
|
| Bill Gates keeps getting fishier every day.
| DarkNova6 wrote:
| looking at how cutthroat he acted as CEO of Microsoft, should
| we have expected anything different?
| ethbr0 wrote:
| I'd hazard that, given its content and writing, can16358p and
| technical reactor geeks are not the primary audience this was
| intended for.
| can16358p wrote:
| We're definitely not the intended audience, though I believe
| what I'd said still applies the same way.
| ethbr0 wrote:
| I'd say he realizes that a bit part of change is
| calibrating a message to a wide audience, to recruit them
| to your cause.
| Jabbles wrote:
| The article implies that sodium cooling is novel, but it's been
| used in (experimental) reactors since the 1950s.
|
| https://en.wikipedia.org/wiki/Experimental_Breeder_Reactor_I...
| pxmpxm wrote:
| Didn't the soviets use it on their fast attack submarines?
| Iwan-Zotow wrote:
| Lead not sodium
| ethbr0 wrote:
| Yes. Lead-bismuth in the 7 boat Alfa class
| https://en.m.wikipedia.org/wiki/Alfa-class_submarine
|
| Presumably you wouldn't want to use something that
| violently catches fire (sodium) in a vehicle designed to
| tolerate nearby explosions.
| hliyan wrote:
| Also a vehicle that is immersed in a liquid that
| violently reacts with it.
| acidburnNSA wrote:
| Presumably. The USA did build a sodium-cooled submarine
| at one point, the Seawolf. Having high thermal efficiency
| increases range, and liquid metals can be pumped
| electromagnetically and completely silently, with no
| moving parts.
|
| It was converted to water coolant later due to technical
| challenges though.
|
| https://en.wikipedia.org/wiki/USS_Seawolf_(SSN-575)
| Aleksdev wrote:
| " I'll start with improved safety. Keep in mind that America's
| current fleet of nuclear plants has been operating safely for
| decades--in fact, in terms of lives lost, nuclear power is by far
| the safest way to produce energy."
|
| Exactly, everyone has panic attacks when you mention any accident
| at a nuclear plant. When the majority of these plants are
| extremely safe.
| mbgerring wrote:
| It's a good thing we have solar, wind and batteries to do most of
| the work of decarbonization before 2050, because it seems like if
| these supposed breakthroughs in nuclear are going to deliver on
| their clean energy promises, we're going to have to buy them lots
| of time to actually get working.
| todd8 wrote:
| Today I posted this
| https://news.ycombinator.com/item?id=35840591 to HN. It is a
| YouTube video with some straightforward statistics that, in my
| opinion, imply a very rough road ahead for Solar and Wind.
|
| The basic problem confronting us is the need for so many mined
| materials to build future solar, wind, and storage facilities.
| It's really quite daunting.
| Gwypaas wrote:
| Capitalism fixes that if the product is something consumers
| demand.
|
| Is the material too expensive then more production are
| brought online and alternatives are found, like cobalt being
| replaced in batteries.
|
| The mineral reserves figures usually touted can be seen as
| the working inventory given the economic conditions today.
| USGS have a good explanation
|
| > Reserves data are dynamic. They may be reduced as ore is
| mined and (or) the feasibility of extraction diminishes, or
| more commonly, they may continue to increase as additional
| deposits (known or recently discovered) are developed, or
| currently exploited deposits are more thoroughly explored and
| (or) new technology or economic variables improve their
| economic feasibility. _Reserves may be considered a working
| inventory of mining companies' supplies of an economically
| extractable mineral commodity. As such, the magnitude of that
| inventory is necessarily limited by many considerations,
| including cost of drilling, taxes, price of the mineral
| commodity being mined, and the demand for it. Reserves will
| be developed to the point of business needs and geologic
| limitations of economic ore grade and tonnage._
|
| > For example, in 1970, identified and undiscovered world
| copper resources were estimated to contain 1.6 billion metric
| tons of copper, with reserves of about 280 million tons of
| copper. Since then, about 600 million tons of copper have
| been produced worldwide, but world copper reserves in 2021
| were estimated to be 880 million tons of copper, more than
| triple those in 1970, despite the depletion by mining of much
| more than the 1970 estimated reserves.
|
| https://pubs.usgs.gov/periodicals/mcs2022/mcs2022-appendixes.
| ..
|
| Appendix C to 2022 Lithium Statistics and Information.
|
| https://www.usgs.gov/centers/national-minerals-
| information-c...
| pydry wrote:
| The road ahead was always going to be daunting. It's just far
| longer, harder _and_ more expensive if with nuclear power.
|
| It's _great_ if you want to share costs with the nuclear
| military industrial complex or you might need to build a nuke
| in a hurry one day. Not so much if you just want to
| decarbonize as cheaply and quickly as possible.
| jackmott42 wrote:
| If you get some time, try doing some napkin math on how many
| batteries you will need to actually do most of the work with
| wind and solar.
|
| It is something you can work out a ballpark number for a given
| % of wind/solar and while not impossible it is _really_ a big
| number. Way beyond what we will get out of actual chemical
| batteries by 2050, we need gigantic scale pump back hydro
| projects on top of that. Trillion dollar range. So Nuclear may
| be less daunting, expensive as it is.
| derriz wrote:
| Why calculate when we have lots of empirical data? There are
| plenty of grids around the world are deriving 40% of their
| energy from wind and/or solar. Up to 65% is relatively easily
| accommodated according to grid engineering orthodoxy with
| current typical infrastructure/tech.
| nine_k wrote:
| Doesn't this mostly happen in counties like Denmark where
| it's relatively easy to buy / sell energy to the grids of
| neighboring countries?
|
| This would work well in denser-populated parts of the US,
| like northeast, and would be harder in Midwest.
| mayama wrote:
| HVDC will handle moving energy on continental scales.
| China makes power in northwest inner parts and moves it
| thousands of kms to the coast for consumption.
| edwiecron wrote:
| Intermittent energy. Doesn't work well for manufacturing at
| all. Your argument, without nuclear, is an argument for
| natural gas and coal.
|
| Industrials need steady power to function. Without nuclear,
| the world is going to just use natural gas. Coal for poorer
| countries. Solar and wind peppered in but not trusted for
| any base load and regionally limited.
| locallost wrote:
| Let me try some napkin math with nuclear. France is usually
| taken as a positive example for nuclear. They have 56
| reactors on a population of 67 million. For the whole world
| to get to that level we are talking about 6k-7k in reactors.
| There are a couple hundred in the world already so let's make
| it 6k. The costs depend on a lot of things, but 10 billion a
| pop is a nice round number and for the majority of the world
| a low estimate. So roughly 60 trillion in construction costs
| only. Then we need to run them and eventually decommission
| and store the waste, which even with much smaller scale
| nuclear programs today will cost hundreds of billions.
|
| Not a realistic solution. We can do more, faster and cheaper
| with renewables. If you can't get to 100% with renewables,
| nuclear should anyway be the last option.
| Zigurd wrote:
| If you want to see some big numbers, look at fossil fuel
| capex. Those big numbers have been spent year after year for
| decades on getting us into this problem. Don't expect to get
| out of it for much less, even though individual renewables
| projects look cheap by comparison. It has to add up to the
| same power output.
| chemmail wrote:
| Analysis put covering the whole US with solar to cost about
| $5 trillion and the world about $65 trillion dollars. A lot,
| but it would pay for itself in about 5 years. The only
| blockade is all the people making all these trillions from
| the oil and all the power sources that make them all this
| money.
| progrus wrote:
| We're never giving you 5 trillion.
| thinkcontext wrote:
| $5T sounds like a lot but it's spread over the lifetime
| of the panels, 20 years. What do utilities spend on capex
| and opex over 20 years.
| ZeroGravitas wrote:
| People will loan it and be paid back, with interest.
| mbgerring wrote:
| Who's "we", you and the mouse in your pocket? The solar
| industry is getting that money, one homeowner, building
| owner, or lot owner at a time. And then, over time, they
| earn a profit in the generated energy! Sorry you hate
| making money doing nothing!
| tpm wrote:
| We'll sooner build green hydrogen generators and peaker
| plants than those modular nuclear plants by the looks of it.
| bryanlarsen wrote:
| Given that the world spends trillions annually on fossil
| fuels, spending trillions on batteries could still save
| money.
|
| That's the thesis of the Tesla "master plan 3.0". It claims
| it will cost $10T to decarbonize the world, but that it would
| save $13T by doing so.
|
| Tesla is obviously biased, but so is everybody else so might
| as well use a source where the biases are clear.
| hannob wrote:
| The problem with that is that nobody who is seriously doing
| energy modelling would propose to do all storage with
| batteries. That's more a popular misunderstanding than an
| actual energy concept.
|
| If you plan for a 100% renewable grid what you do is that you
| use different types of storage for what they're good at.
| Batteries can play a role in short-term storage, but for
| seasonal storage they're clearly not a good choice.
| Electrolyzers and H2 gas peaker plants (or maybe ammonia
| instead of H2) look like the most promising option.
|
| I wish more people knew this, because all this "I calculated
| how many batteries you'd need for your renewables, we need
| nuclear!" clearly is neither an informed take nor helpful.
| marsven_422 wrote:
| [dead]
| m348e912 wrote:
| I am curious what HN thinks of RFK Jr's position on nuclear
| power. He was a guest on the latest all-in podcast and went into
| his positions in-depth.
|
| Something to the affect that nuclear is more expensive than other
| traditional and renewable sources. No traditional insurance
| company will insure nuclear plants. No traditional bank will
| finance nuclear builds. Nuclear power is still too risky to be
| considered as a viable power source.
|
| He adds, instead continue focus on wind and solar and improve
| transmission (using DC) to make it a viable power system for the
| US. Is he uninformed? Direct current (DC) is the worst kind of
| power type for long distance transmission. (Unless something has
| changed).
|
| My understanding is that solar and wind generated power has shown
| not to be consistent enough and too localized to currently meet
| US power demands.
| p1mrx wrote:
| Powering the US without emitting CO2 generally requires either
| (1) lots of new transmission lines to share wind/solar between
| regions, or (2) lots of nuclear so we don't have to.
|
| > Direct current (DC) is the worst kind of power type for long
| distance transmission.
|
| AC was traditionally used for long range transmission because a
| transformer can easily increase or decrease the voltage.
| Transmitting DC is actually more efficient, but it requires
| modern semiconductor technology to generate the voltages
| necessary.
|
| > My understanding is that solar and wind generated power has
| shown not to be consistent enough and too localized
|
| That's why we would need transmission to make it non-local.
| danielodievich wrote:
| Excited to see the progress on this, as I have local connections.
|
| One of my nearby neighbors is the engineering manager of this
| facility. He's an ex nuclear sub XO who before that was running
| launch operations for Blue Origin. He knows what he's doing in
| building things.
|
| And another neighbor - although I only met him few times via our
| mutual kids being in same class - is the brain guy with two PhDs
| in nuclear engineering. I think he knows what they are designing.
| Plus we both drive same model car with custom license plates, his
| is nuclear-themed. Points!
| Drblessing wrote:
| That's awesome. What's the reception in the town of the new
| plant?
| ChatGTP wrote:
| [flagged]
| Drblessing wrote:
| Cool now hook it up to Bitcoin miners
| selcuka wrote:
| I still believe it is safer than water cooled plants, but Mr.
| Gates doesn't seem to have touched the downsides of using sodium
| [1]:
|
| > A disadvantage of sodium is its chemical reactivity, which
| requires special precautions to prevent and suppress fires. If
| sodium comes into contact with water it reacts to produce sodium
| hydroxide and hydrogen, and the hydrogen burns in contact with
| air. This was the case at the Monju Nuclear Power Plant in a 1995
| accident. In addition, neutron capture causes it to become
| radioactive; albeit with a half-life of only 15 hours.
|
| > Another problem is leaks. Sodium at high temperatures ignites
| in contact with oxygen. Such sodium fires can be extinguished by
| powder, or by replacing the air with nitrogen. A Russian breeder
| reactor, the BN-600, reported 27 sodium leaks in a 17-year
| period, 14 of which led to sodium fires.
|
| [1] https://en.wikipedia.org/wiki/Sodium-
| cooled_fast_reactor#Dis...
| belorn wrote:
| How does molten salt solar plants solve those problems?
| _a_a_a_ wrote:
| Because a salt is an already-reacted substance. Molten sodium
| and molten sodium chloride are utterly different, for
| example.
|
| https://onlinelibrary.wiley.com/doi/10.1002/cite.202000137
|
| "In commercial CSP plants, almost exclusively a non-eutectic
| salt mixture of 60 wt % sodium nitrate and 40 wt % potassium
| nitrate is utilized. This mixture is commonly referred to as
| Solar Salt"
| tuatoru wrote:
| I believe they use salts of other metals, not sodium. But in
| any case, in a salt the metal has already reacted with
| something and is unlikely to react further with commonly
| encountered substances.
| ChrisMarshallNY wrote:
| I've heard that salt has corrosion issues. These may also
| apply to sodium, though.
| selcuka wrote:
| The Wikipedia article says that sodium actually protects
| metals from corroding, but I am unable to see how that
| works by reading the citation.
| hermitcrab wrote:
| Some very reactive substances react with their container
| vessel to form a non-reactive 'skin' on the inside of the
| vessel. I don't know if they applies in this case.
| eig wrote:
| Is the heat transfer fluid for these nuclear plants considered
| radioactive? I honestly don't know.
|
| If so, then if a leak happens I'm guessing you have bigger
| problems than its chemical reactivity. Any leak is a major
| nuclear cleanup whether it's water or sodium. Maybe the
| chemical hazard is just a drop in the bucket compared to the
| nuclear hazard, in which case why wouldn't they use sodium?
| sandworm101 wrote:
| With a 15-hour halflife, no matter the initial disaster, any
| radioactivity problems associated with the sodium coolant
| would disappear in a few days.
| tzs wrote:
| And even in those few days it probably won't affect things
| that aren't close to the accident.
|
| A sodium 24 atom decays to an excited magnesium 24 atom by
| emitting a 1.39 MeV electron. That has a penetrating power
| of about 5 m in air.
|
| The excited magnesium 24 quickly drops to the ground state
| by emitting two gamma rays, one at 2.76 MeV and one at 1.38
| MeV. Those won't get past maybe 150 m of air.
| brindy wrote:
| What happens if that contaminates something else? I presume
| that would have a different half life? Not a physicist, so
| genuine question.
| amluto wrote:
| In general, radiation emitted from a radioactive
| substance is not itself radioactive, nor is it
| particularly dangerous once it stops moving. The usual
| radiation consists of:
|
| Alpha particles: literally just Helium minus the
| electrons. Only harmful because it moves _fast_ at first.
| Even then, it's only really harmful if it gets emitted
| inside your body. It barely penetrates skin.
|
| Beta: electrons and positron. Electrons will chemically
| react with something very quickly (except in a vacuum,
| they don't stick around as free electrons). Positrons
| will find a nearby electron and be annihilated.
|
| Gamma: very high frequency light. Can be quite dangerous,
| but doesn't persist.
|
| None of these transmute other things into radioactive
| isotopes. The kind of radiation that makes other things
| radioactive is neutrons, but those are very unusual
| outside of a nuclear reactor. Fission and some fusion
| reactions make neutrons, and a couple of radioactive
| elements make small amounts, and that's about it.
| Neutrons also don't persist in the environment (and,
| interestingly, they don't persist very long in space
| either).
|
| So a spill of hot radioactive sodium is nasty. It's hot,
| and it's highly reactive. But it's so reactive that it
| will all react! Sodium can't meaningfully contaminate
| groundwater, because it will just turn into salts. It can
| mess up soil pH, because the reaction product is lye, but
| that can be remedied by an acid. (Other than its pH, lye
| is pretty harmless. You use flush it down your drain to
| clean your drain, and you can even use it to make
| pretzels!) The radioactive sodium-23 emits radioactive
| sodium, but much less than 1 trillionth will remain after
| a day -- what's left is non-radioactive magnesium, which
| is harmless.
|
| So I wouldn't want it be around a sodium leak, but
| visiting it a day or two later while wearing a good pair
| of boots (for protection against any remaining lye) seems
| quite safe.
| tzs wrote:
| Could an electron emitted by beta decay of a neutron on
| the sodium hit the nucleus of something else and combine
| with a proton their to form a neutron, producing an
| unstable isotope of that something else?
| amluto wrote:
| Electron capture by a nucleus is a thing, but as far as I
| know, this only happens to any significant extent to
| unstable nuclei that naturally decay that way. It's
| probably _possible_ for a high enough energy electron to
| hit a stable nucleus and convert a proton to a neutron,
| but I've never heard of it (although I'm not an expert).
| So I don't think anyone needs to worry about this.
| Waterluvian wrote:
| Someone smarter may correct me but my understanding is
| that radioactivity doesn't transfer like that.
| Contamination means for the isotope to find its way into
| a system (like a human body) and then stay there,
| radiating harmful particles from the inside.
|
| If you were to be contaminated by ingesting some
| radioactive sodium, it would still decay and be gone
| within days.
| hermitcrab wrote:
| The fact that it decays quickly also means that it would
| be very damaging if it got inside you somehow before it
| had decayed.
| nine_k wrote:
| No, the half-life is a property of a nucleus, which does
| not take part in chemical reactions.
|
| The normal way of dealing with cases of taking in
| radioactive abd bio-active elements, like iodine, sodium,
| (and even strontium which tends to take place if
| calcium), is taking excessive amounts of the same
| element, but a normal, stable isotope. Taking in some
| excessive table salt (cheese and chips anyone?) should be
| pretty easy.
| johnchristopher wrote:
| So. Can someone Eli5 to me ? There's a large consensus on climate
| change (it's caused by humans, it's getting worse, it will
| increase catastrophes). Only people on the fringe regularly and
| vocally claim otherwise (there's no climate change, it's natural,
| it won't have any impact, impacts are good, it's all activist's
| fault because they scared use and we didn't act).
|
| Reading HN and its heated debates around this topic, I don't see
| any consensus on nuclear vs renewables. Not even a consensus like
| "it's the mix, stupid".
|
| Do our scientists have a consensus on how to power our societies
| in regards to climate change ?
|
| If not, is it because it's too soon to settle on something ? Or
| there's too much bad science fabricated ? Or do we have have the
| choice, all things being equal: go full nuclear, or go full
| renewables or go mix but... as a specie we (or our leaders)
| collectively choose not to ?
| skippyboxedhero wrote:
| You can tell how well someone understands a topic by their
| ability to explain the argument of those who they disagree
| with.
| bryanlarsen wrote:
| This is an economics and politics question, not a science
| question. Science has delivered the tools, it's a question of
| how we pay for it and who pays for it.
|
| Scientists don't have a good track record providing answers to
| economics and political questions. OTOH, neither do economists
| nor political scientists.
| ZeroGravitas wrote:
| There is broad consensus amongs experts.
|
| With recent improvements in renewables, renewable positive
| people have said "we now think 100% wind, solar, battery is
| feasible" after a few years of saying 80% renewables is doable
| and the last 20% is tricky and people less enthusiastic about
| renewables are saying "we're still thinking that having 10-20%
| nuclear might work out slightly cheaper".
|
| Even countries like France and Japan which are very nuclear
| positive, are not talking about 100% nuclear and have
| aggressive renewable rollouts planned:
|
| https://www.reuters.com/business/energy/frances-renewables-g...
|
| The extreme anti-renewable, pro-nuclear opinions you find on HN
| are bizarre and nonsensical. They're basically remnants of
| climate change denial.
|
| edit: for example this is a summary from 2017 where they're
| nervously optimistic about getting to 100% but are fairly
| confident about getting to 60%
|
| https://www.vox.com/energy-and-environment/2017/4/7/15159034...
|
| > Again, it's all about balancing out VRE. The easiest way to
| do that is with fast, flexible natural gas plants, but you
| can't get past around 60 percent decarbonization with a large
| fleet of gas plants running. Getting to 80 percent or beyond
| means closing or idling lots of those plants. So you need other
| balancing options.
| juujian wrote:
| The academic debate is generally dominated by two concerns
| around nuclear energy. The first one is that nuclear energy is
| by far the most expensive form by unit of energy produced. New
| project like to claim the opposite, but that is always before
| cost overruns and years of delay. In general the final price
| tag may be 2-3x as much than the estimate. Plant Vogtle in
| Georgial for instance went for $14B to $34B. Nuclear power
| plants also need water for cooling, so they are sensitive to
| both drought and extreme heat. Which is generally when you most
| desperately need electricity. Meanwhile, the same crowd claims
| to have economics on its side when railing against renewables,
| which are the cheapest unit by unit, and a great contingency
| plan for extreme weather events, like the disasters in Haiti.
|
| But the bigger concern raised is that some calls for nuclear
| are a "cop-out". Nuclear happens to be great for damming up
| demands for renewable energy, while buying time for existing
| production capacity. It is not unusual for projects to run for
| years before any tangible construction is done, and even then
| it is not unusual for advanced projects to be cancelled for
| cost overruns. Meanwhile, you can have a solar panel on your
| roof in a couple of months. So it has some of the qualities of
| ExxonMobil calling for a carbon tax because they know it is
| unlikely to happen.[^1]
|
| So overall, the academic debate over nuclear does not have much
| to do with its technical characteristics, it mostly has to do
| with the political dimensions of who the advocates are and what
| their goals or interests are. And if you are in favor of
| nuclear, it is still a good idea to look at who is on your side
| and consider what their motivation for fighting that fight is.
|
| [^1]: https://unearthed.greenpeace.org/2021/06/30/exxon-
| climate-ch...
| yellowapple wrote:
| If you're opposed to nuclear, it's also a good idea to look
| at who is on your side and consider what their motivation for
| fighting that fight is: https://www.forbes.com/sites/kensilve
| rstein/2016/07/13/are-f...
| juujian wrote:
| Touche! I would argue though that the anti (existing)
| nuclear energy movement is separate from advocacy for
| investing into renewables over nuclear for new capacity.
| pas wrote:
| Nuclear energy debate suffers from the classic problem of
| impedance mismatch between the supporters and detractors
| regarding the unit economics at scale.
|
| Current data we have is based on bespoke plants. Utterly
| maddening overhead. This is the cost disease plaguing any
| kind of infrastructure/construction/high-unit-cost projects
| in the "developed world".
|
| If you build one plant per decade, then there's no incentive
| to streamline, no economies of scale, no overlapping s-curves
| of improvement, no real industrialization and
| standardization.
|
| Lack of scale leads to discontinuities, change aversion, lack
| of innovation, pork and barrel politics, and so on.
|
| See the Boeing 737 MAX fuckup. The regulatory environment
| created a cost jump so huge, that Boeing risked too much.
| HDThoreaun wrote:
| Korea build nuclear at scale and it's barely cheaper, still
| the most expensive form of electricity.
| trothamel wrote:
| They've started construction on 2 plants in the past
| decade. That's not really "at scale".
| juujian wrote:
| That sounds very Chaebol-y
| pas wrote:
| No one is building nuclear at scale currently. Maybe with
| SMR it will be possible.
| juujian wrote:
| I think it's even worse, because so many plants were built
| in the 70s and 80s, and then there is a large gap. So we
| don't even have the routine and economies of scale
| associated with an s-curve anymore. And new plants promise
| better safety and new features, so we would really start
| all over again on the s-curve.
| acidburnNSA wrote:
| > The first one is that nuclear energy is by far the most
| expensive form by unit of energy produced.
|
| Now that the world is waking up to understanding the LCOE is
| a wholly inappropriate metric for systems cost comparisons,
| this statement is more clearly no longer true.
|
| With the firming included, nuclear is right there in the mix,
| cheaper than most 100% ___ with storage options.
|
| https://www.ctvc.co/firming-costs-renewables/
| juujian wrote:
| You might have included the wrong link there. And with
| nuclear, always consider total cost, not operating cost.
| Not impossible to determine, but less reliable data
| floating around. You would have to take the cost of all
| failed projects as well as the cost of decommission and
| storage. For nuclear, the cost is a little bit funny. You
| have huge upfront cost, then lower running cost, and then a
| very long tail obviously.
| Ericson2314 wrote:
| The anti-nuclear camp is one of the greatest illiteraces
| acceptable to mainstream and high society.
|
| That's the unfortunate reason why you don't see more consensus
| on this issue.
| JumpinJack_Cash wrote:
| > > I don't see any consensus on nuclear vs renewables. Not
| even a consensus like "it's the mix, stupid".
|
| What I got is that nuclear (fission v.3/4 and fusion) are the
| "swing for the fences" technologies, while renewables are the
| "stuff largely remains what is today but without CO2 so people
| 80 years from now won't be living in a +3C world"
|
| Personally I am rooting for fission and fusion because
| technological stasis is a recipe for disaster. Nukes will be
| flying way before the 3C treshold becomes a concern, people
| need constant improvement in their quality of life, if that
| doesn't happen they'll seek satisfaction into subjugating
| others.
| gessha wrote:
| A mix would always be nice because of diversification. I don't
| think anyone wants full nuclear.
|
| Building water, geo and hydro is (as of now) cheaper to build
| compared to nuclear [citation needed]. And it's also "free"
| energy. Why not use it to reduce the usage of nuclear fuel?
| djha-skin wrote:
| > When it opens (potentially in 2030),
|
| So this is an announcement of an announcement. Nuclear power
| plants have a very long history of being shut down right before
| they open, so now I'm more skeptical that this will ever work.
|
| This happened a lot at Hanford in Washington. They built
| something like four power plants up there but when they were 90%
| complete Congress only approved one of them. It sounds really
| cool Congress approves its building but once it's about to open
| congress gets scared because of how people feel about nuclear
| power plants close to their house.
|
| Regardless of how cool they say their technology is I will be
| more interested when it actually opens.
| Mistletoe wrote:
| https://www.wyomingpublicmedia.org/natural-resources-energy/...
|
| > The start date will likely be pushed back two years to 2030,
| according to a press release from the nuclear plant developer
| TerraPower. The main reason is Russia's war in Ukraine, as Russia
| is the only commercial supplier of the highly enriched uranium
| (HALEU) the plant needs to run.
|
| Great...
| neffo wrote:
| Importing enriched uranium from an adversary leads to
|
| > America's energy independence
|
| Sure.
|
| > First, water isn't very good at absorbing heat--it turns to
| steam and stops absorbing heat at just 100 degrees C.
|
| Umm, this is completely wrong and backwards.
| throwaway50606 wrote:
| America's energy independence [from fossil fuels] - yeah
| indeed it does. Also, what stops America from producing its
| own?
| crote wrote:
| Uranium mining has significant health risks, and it is
| pretty much guaranteed to result in significant pollution
| of the surrounding area. The enrichment phase isn't much
| better either.
|
| Turns out the US has things like worker protection laws and
| environmental protection laws. Producing it locally is
| expensive, it is much cheaper to outsource the problem to a
| country with a more _relaxed_ view on the issue.
| ClumsyPilot wrote:
| There is plenty of uranium mining in developed nations
| and the price of nuclear fuel is not particularly
| relevant - 90 of the cost is pther stuff
| Zigurd wrote:
| A bit of googling shows there are about 1,000 abandoned
| uranium mining/prospecting sites in New Mexico. Probably
| many with uncontained tailings. Yikes. But we can count
| on extraction projects to clean up after themselves now.
| Right?
| literalAardvark wrote:
| Of course! And they'll also maintain the tailings dam for
| the thousands of years required.
|
| Why would we even doubt that?
| throwaway50606 wrote:
| Do you really think the situation in Russia is better?
| Zigurd wrote:
| No. It is very likely worse. Same for other places with
| less regulation than the US.
| throwaway50606 wrote:
| So, it'd be preferable to move it to the US where it can
| have better oversight and there's a potential of
| regulatory-driven change.
| le-mark wrote:
| Oh to never have encountered a steam table, some people never
| do I suppose. Some are born to it..
| kyrofa wrote:
| > Safety isn't the only reason I'm excited about the Natrium
| design. It also includes an energy storage system that will allow
| it to control how much electricity it produces at any given time.
| That's unique among nuclear reactors, and it's essential for
| integrating with power grids that use variable sources like solar
| and wind.
|
| I'm surprised this is all he says on this matter. As far as I'm
| aware, this problem is largely unsolved, and one of the reasons
| dams can't go away: they're the only power generation technology
| that we can spin up and down in response to fluctuation in wind
| power and so on. That's because we don't have a good solution for
| storing energy on this scale, and thus must use the energy we
| generate. Have we finally come up with one? A water battery
| (pumping water into a reservoir behind a dam) is the only one I
| know of, which doesn't seem to scale well.
| aksss wrote:
| > which doesn't scale well
|
| It also has the problem of only being applicable to geographies
| with abundant water and the topography suited to create giant
| reservoirs.
| kyrofa wrote:
| Right, I don't mean that individual water batteries don't
| scale well, but that the concept in general doesn't scale
| well as a solution to this problem. That's definitely one of
| the reasons.
| godelski wrote:
| Interestingly there has been a lot of discussion about hydrogen
| lately[0] because the Inflation Reduction Act provides a tax
| credit for production of clean hydrogen (e.g. hydrogen not from
| methane). Nuclear is one of the best possible methods to ways
| to generate this (high electricity, high heat) given that its
| operation does not generate carbon (just like renewables). The
| problem? Nuclear power generates $30/MWhr and will make between
| $60-$70MWhr producing hydrogen. Sounds like a win, but reactors
| are already at 90% capacity and supply ~20% of the US's energy
| and half of our zero emission energy.
|
| Variability isn't that much of an advantage. Excess energy can
| often be sold off as well, reducing other areas' reliance on
| fossil fuels. France, Norway (almost all hydro), and Sweden
| (also a major nuclear player) and the main energy exporters in
| Europe (also lowest energy based carbon emitters)[1,2]. We see
| a similar thing with Quebec (major nuclear). But it is
| concerning given that nuclear is the main source of zero
| emission energy in the American South East[3]. Gates probably
| isn't concerning himself with the variability since there's no
| shortage of regions where selling a zero emission source isn't
| going to help reduce its neighbors energy emissions. The only
| areas where there is a shortage is where regions already rely
| heavily on either nuclear or hydro (or a combination).
|
| There's no reason to not run at max load. You either sell the
| energy or your produce hydrogen. This is also a big reason that
| a carbon tax makes nuclear a viable option. Just for reference,
| here's an annual solar radiance map[4], wind (10m)[5], and
| hydro[6] as they might help explain the situation in the South
| East.
|
| [0] https://heatmap.news/economy/the-nuclear-hydrogen-conundrum
|
| [1] https://www.enappsys.com/interconnectorreview/
|
| [2] https://app.electricitymaps.com/zone/FR
|
| [3] 80% of TVA's zero carbon, 77% of SCS, 86% of Duke
| Carolinas, 81% of Duke Ease, 80% of PJM(looking at 12 months)
|
| [4] https://www.nrel.gov/gis/assets/images/solar-annual-
| ghi-2018...
|
| [4.5] find other maps -- look at DNI -- for different months
| and energy sources here https://www.nrel.gov/gis/solar-
| resource-maps.html
|
| [5] https://www.nrel.gov/gis/assets/images/wtk-10m-2017-01.jpg
|
| [6]
| https://www.nrel.gov/gis/assets/images/map_hydrogen_kg_count...
| p1mrx wrote:
| Any of the high-temperature reactor designs (sodium, molten
| salt, TRISO, etc.) can be combined with thermal energy storage.
|
| Light water reactors only get up to 300degC, which is barely
| hot enough to spin a turbine. At >600degC, you can heat an
| intermediate fluid, lose some energy, and still spin a turbine.
| kyrofa wrote:
| So the idea is that there are chambers of molten salt (or
| similar) that can be heated when a spinning turbine is not
| needed, and it'll stay hot enough to spin one later? Any idea
| how long it stays hot? What happens when they're all already
| heated?
| p1mrx wrote:
| 12-24 hours of molten salt storage should be enough to
| generate power all day, and sell it at times when
| electricity is most expensive. There's not much point
| storing for multiple days, when the reactor itself behaves
| like long-duration storage.
|
| If your reactor is producing energy with no buyers, and
| your thermal storage is full, then you probably should've
| built it somewhere else, but in that case you can just
| power down the reactor.
| vrglvrglvrgl wrote:
| [dead]
| trallnag wrote:
| I have zero respect for Bull Gates' opinion, ideas, and beliefs.
| pcdoodle wrote:
| Wanna grab some pie later?
| Drblessing wrote:
| The anti-nuclear sentiment on this board is perplexing....
|
| Way to go! I'm excited for the future of Nuclear fission, it's
| clearly going to be an important part of the sustainable future.
| deepmauka wrote:
| I think the real story here is that the project was successfully
| sold to the people of Wyoming, who now appear to be shouldering
| the responsibility of decarbonization.
| FollowingTheDao wrote:
| ...and Gates makes a profit. This makes me worry about how the
| plant is being sold. I mean what are the unknown unknowns?
|
| Does a statement like this give you confidence?
|
| "TerraPower says these risks have been considered and addressed
| as much as reasonably possible."
|
| https://cowboystatedaily.com/2023/01/25/former-dea-nuclear-s...
|
| "Tallen said he's not ideologically opposed to nuclear power.
| He said he rubbed elbows with that crowd years ago, but it's
| not where he stands today.
|
| "The distrust of nuclear power is one of the major ideological
| tenets of left-wing, anti-establishment politics," Tallen said.
| "I had to say to them, I can't agree with you on many of your
| basic assumptions. I'm just saying that this particular
| [Natrium] technology pursued the way it is right now - I don't
| think it's a good idea." "
| DarkNova6 wrote:
| For some reason "reasonably possible. Sounds a lot like
| "economically reasonable".
|
| Which should absolutely worry anybody who has the faintest
| ideas about how insidious Sodium is as a cooling material.
| LinuxBender wrote:
| I am in Wyoming. I think it makes sense to the people here. The
| state is going green and the mines are shutting down. A
| suitable replacement needs to be created first before all the
| mines are decommissioned. Some of the people will be employed
| by the nuclear plant and some will have to move or retire. The
| person I know at the mine is retiring soon. As this state
| provides a lot of power to the US power grid currently with
| coal [1] I think it makes sense to transition as much of it as
| possible to nuclear and renewables. The state is not limiting
| itself to one source, all options are on the table and more
| options are being added soon. We do not show up as a big number
| for wind and solar power because it is only augmenting some
| power for some of the small towns and not the US grid yet [2].
|
| [1] - https://www.eia.gov/state/?sid=WY#tabs-3
|
| [2] - https://www.transwestexpress.net/
| deepsquirrelnet wrote:
| Kind of surprising, given that coal mining is one of their
| largest industries. I'm actually kind of shocked.
| ggm wrote:
| _Unlike water, the sodium doesn't need to be pumped, because as
| it gets hot, it rises, and as it rises, it cools off_
|
| Mr Gates, can you hire another copy editor please?
| hulitu wrote:
| Well, the same phylosophy is used in the Windows operating
| system with great results. /s
| Kiro wrote:
| What's the problem?
| yellow_lead wrote:
| Water also rises as it gets hot, and cools off
| Pepe1vo wrote:
| "cools down" is grammatically more correct.
| ggm wrote:
| Do you know what hot water does? Like liquid sodium, it
| rises. The point here isn't that liquid sodium has some
| magical lifting property water doesn't have, it's the
| enthalpy, latent heat: water can't hold as much heat energy
| without pressure to contain the phase change into steam. If
| you remove hot things from the primary heat source they
| cool. The sodium is just more tractable.
|
| Einstein and (Leo) Szilard had patents in liquid metal
| pumped refrigerator designs using electro magnetics instead
| of mechanical pumps, Richard Rhodes talks about them, and
| applications to cooling nuclear systems.
| javajosh wrote:
| _> It also includes an energy storage system that will allow it
| to control how much electricity it produces at any given time._
|
| Does anyone know more details about this? I'm thinking it's a
| monster flywheel. Which would be very cool.
| RandomChance wrote:
| The Natrium data sheet[1] says that it is "Molten salt energy
| storage", so based on the diagram[2] it appears that salt (not
| sodium) is being pumped to to the reactor and stored in large
| tanks, similar to thermal mass solar installations. I assume
| the sodium is internal to the reactor only, but can't say for
| sure.
|
| [1]:https://www.terrapower.com/wp-
| content/uploads/2023/03/TP_202...
| [2]:https://www.terrapower.com/our-work/natriumpower/
| ZeroGravitas wrote:
| Presumably just insulated storage of hot stuff to act as a
| buffer between the heat production and use for electricity
| generation. Very similar to what CSP plants do.
| zdragnar wrote:
| The molten sodium is a storage of energy in the form of heat.
| Keep it well contained and insulated, and you draw off only the
| heat that is needed to convert to kinetic energy, which then
| generates electric current through induction.
|
| Like a monster flywheel, there are all kinds of things that
| might go wrong, but they're all far less scary than Chernobyl
| style meltdowns.
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(page generated 2023-05-06 23:02 UTC)