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Is Nuclear Energy the Answer?

Posted on 13 June 2019 by scaddenp

Abbott 2011  and Abbott 2012 doesn’t think so but perhaps there are better analyses? For discussions of economics, levelized cost estimates of various electricity technologies can be found here and here.

Nuclear energy is quite commonly proposed as the solution to reducing GHG emissions. As soon as this gets raised on an article's comment thread, there has been a bad tendency for on-topic discussion to be completely derailed by proponents for and against.

We have repeatedly asked for nuclear proponents to provide an article for this site which puts the case based on published science but so far we haven't had a taker. The proposal would need to be reviewed by Sks volunteers. In lieu of such an article, this topic has been created where such discussions can take place.

However, in the absence of a proper article summarizing the science, stricter than normal moderation will be applied to ensure that all assertions made for or against are backed by references to published studies, preferably in peer-reviewed journals.

Update - October 2020

This post has been up for a little over a year now, and has received over 200 comments. Now seems like a good time to add some clarification.

First of all, the challenge to "nuclear proponents" to provide an article requires that the article "summarize the science". It is not the desire of Skeptical Science to provide a one-sided, pro-nuclear assertion. The expectation is that an article would provide a balanced review of all aspects of nuclear energy as a practical, affordable, realistic source of low-carbon energy.

If you think of yourself as a "nuclear advocate", then writing a balanced article will be difficult for you. This is not a place for "lawyers' science", where the role is to pick a side and pretend there is no other reasonable argument. This is not about winning an argument - it is about coming to a common understanding based on all the available evidence.

If you think that criticism of your position represents an "anti-nuclear bias", then writing a balanced article will be difficult for you.

If you think that you are the only one that truly understands nuclear energy, then you are probably wrong.

Review of any submitted article will not be at the level of a review of a professional journal article, but anyone submitting an article needs to be prepared to have their positions examined in detail for weaknesses, missing information, lack of support in the peer-reviewed literature, etc. If you find it tough to accept criticism in the comments thread, then you will not find review any gentler.

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Comments 201 to 205 out of 205:

  1. I use the data I can get ahold of; (easily accessible) IEA data goes out to 2017/2018.

      total energy electricity and heat only  
    Germany 8.2 3.6 36% non-hydro renewables; 13% nuclear
    Europe 5.9 2.1 Europe, not the EU
    Denmark 5.5 1.5 62% non-hydro renewables; 0% nuclea
    Sweden 3.6 0.7 21% non-hydro renewables; 49% nuclear
    France 4.4 0.5 10% non-hydro renewables; 86% nuclear

    As we can see, Danish total energy emissions per capita is slightly lower than Europe. I clearly stated Europe (not the EU) and I clearly stated per capita numbers, not absolute. I clearly stated IEA data and the dates.

    When car-crazy France has 1.5 tons per capita less total emissions (than the European average) and bicycle-loving Denmark only 0.4 tons less - yeah - it is slightly lower. So MA Rodger - I am not 'badly wrong'.

    Danish E&H is better, but really not comparable to Sweden (a third! of the European average) or France (a quarter! of the European average).

    Danish per capita emissions in E&H (where Wind/Solar/Nuclear currently compete) are blown out of the water by Sweden (under half! of Danish emissions) and France (a third! of Danish emissions). Germany is left in the dust on both measures of emissions.

    2017-2018 IEA data
    total is the cross-sector emissions in t/capita

    • https://www.iea.org/countries/Germany
    • https://www.iea.org/countries/europe
    • https://www.iea.org/countries/Denmark
    • https://www.iea.org/countries/Sweden
    • https://www.iea.org/countries/France
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  2. michael sweet @199 per your comment

    "Nuclear supporters frequently claim data from 1999 to support nuclear in 2020. Here Preston Urka uses outdated and incomplete (and uncited) data. Previously he compared 2019 solar costs in the UAE to nuclear costs from 2009. It is easy to make something look good using outdated and incomplete data."

    You just can't read the links and caveats can you?

    I clearly state where my data came from - is it the best data - no, but it is what I had available. I note the discrepancies. Your comments really are not in the spirit of courteous discourse.

    I note you also have used Wikipedia (in preference to IEA data no less! where the data is available!!!).

    ---

    "Nuclear supporters like Preston Urka are claiming nuclear can supply a portion of electricity only. Electricity is only about 20% of all power."

    First, the IEA disagrees with you about 20% of all power. I suggest you re-research that number. With electrification of industry, transport, etc this share will just increase.

    Second, I will let you in on a secret - EV batteries work just as well on electricity from NPPs as from RE! - I know! Who knew???? It also turns out that other appliances and tools are the same. Amazing!

    Third, nuclear produces a lot of heat.

    • Process heat is useful in industry.
      • About 70-90% of their total energy use is process heat.
      • Using process heat directly is more efficient than generating electricity and using electricity to generate heat.
      • Note there are no current cases, but the technology is engineering, not ground-breaking science.
    • Process heat can also be used to create synthetic fuels for transportation and agriculture (in addition to EV-type juice). 
    • Process heat can be used directly in transportation.
      • The US Navy has the greenest submarines in the world!
        • I believe many on this website are Australian - you guys should stop buying those nasty, carbon-dioxide emitting diesels. The idea that you will convert a green French submarine into a dirty emissions scow is horrifying!
      • The Russians have green icebreakers!
      • Large cargo ships (currently burning bunker oil and accounting for 1-3% of global emissions) can easily be converted to nuclear - using existing military designs - or some of the newer micro reactors.
    • Wind? - no, no process heat from wind. Need to lose energy in converting electricity to heat.
    • Solar PV? - no, no process heat from solar PV. Need to lose energy in converting electricity to heat.
    • Solar CSP? - Yes, but solar CSP tends to be in sunny arid deserts. For example, one of the biggest US chemical plants is Dow Chemical in Midland, Michigan. It is not in a sunny desert, but a cloudy northern climate.
      • Pipe the coolant north! - a 1000 km from the Mohave to Midland? (Not sure on this distance michael sweet, better check me!) - not a great idea, efficiency-wise.
      • Move the plant south? - ok, but you just blew the carbon budget.
      • Close the old plant, and open a new southern plant? - ok, but you just blew the carbon budget.
      • Again, I believe this website has an Australian connection - How many 10MW+ Solar CSP plants are in Australia? Are any of 10MW+ solar CSP plants providing process heat to Australian industry? 1MW? - I mean 1MW is just a large diesel generator. And solar is soooooo cheap!
    • Lastly, nuclear process heat can go from 350 C to 1200 C - a huge range of industrial process (most of which start around 600).
      • Solar CSP - well, from 250 C to about 650 C - just where process heat starts going good.
      • ammonia starts at 400 C
      • glass starts at 500 C
      • cement starts at 800 C
      • thermo-electrolysis to produce hydrogen at 850 C
      • aluminum starts at 940 C
      • silica glass starts at 1000 C

    Lastly, I have never claimed, in this forum, any other forum, or in person that nuclear can supply electricity only.

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    Moderator Response:

    [DB] Off-topic, sloganeering and empty rhetoric snipped.

  3. Speaking of heat and nuclear power plants...

    Climate change—particularly intense heat—is advancing so rapidly that it poses physical as well as credit risks to America’s aging nuclear fleet, a new report from Moody’s Investors Service finds.

    “Our plants are fairly hardened to severe weather,” said David Kamran, a projects and infrastructure analyst at Moody’s and the lead author of the report. “But climate change is moving quickly.”

    America’s nuclear power plants produce roughly 20% of the country’s electricity and represent more than half of all of its carbon-free power generation. After the earthquake and tsunami that caused a meltdown at Japan’s Fukushima-Daiichi nuclear power plant in 2011, the U.S. Nuclear Regulatory Commission asked domestic plants to conduct their own assessments of risks from climate change and other natural hazards. A 2019 Bloomberg review of correspondence between the commission and owners of 60 plants concerning those assessments found that 54 of their facilities weren’t designed to handle the flood risk they now face.

    Nuclear Plants Face More Heat Risk Than They’re Prepared to Handle by Leslie Kaufman, Finance, Bloomberg News, Aug 19, 2020

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  4. MA Rodger @197
    Yes, it takes time to build an NPP (or any other power plant).

    However - Unit 1 of the Barakah nuclear power plant in the Al Dhafrah region of Abu Dhabi has been connected to the grid and has begun supplying electricity to the UAE. 19 August 2020

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  5. Note to Moderator (I have to post here as SkS doesn't respond to emails)

    I ask you to amend this post _michael sweet @196_ with an update to correct misinformation as future readers may not find a subsequent post correcting it. The misinformation is clearly a highly prejudicial statement which severely misleads any reader.

    I ask you to leave his statement: "It would be illegal to build these plants in the USA or EU." so that future readers will be able to assess his care and attention in marshaling his arguments.

    The update I suggest is the following:
    With respect to the Barakah APR1400 reactors, the US NRC has found "VI. Issue Resolution A. The Commission has determined that the structures, systems, and components and design features of the APR1400 design comply with the provisions of the Atomic Energy Act of 1954, as amended, and the applicable regulations identified in Section V of this appendix; and therefore, provide adequate protection to the health and safety of the public." - In other words, the reactors would be legal in the US.

    ps - apologies for poor formatting of @204

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    Moderator Response:

    [DB] Moderation complaints again snipped.

  6. Preston Urka at 202

    You say "[in my post 199] You just can't read the links and caveats can you?"

    At post 199 I was responding to your post 198.  Your post 198 has no links to read.  I note that your post 202 also has no links to support your arguments.  I cannot read links that are not provided.

    Your post 202 consists primarily of your fantasy use of nuclear waste heat to power industry.  I note that you concede that zero current nuclear reactors use their waste heat.  Since you cite no peer reviewed papers, or even industry white papers, and you claim no education, training or experience in the design or running of nuclear plants, idle speculation about possible use of waste heat is sloganeering so the moderator has deleted it.

    You additionally mention your fantasy that nuclear power could be used in shipping.  Only one freighter has been built wiith a nuclear power plant.  It is uneconomic to run since a reactor requires many more operators than a traditional ship.  Military vessels do not care about the extreme cost.  In addition, you would need approximately 50,000 reactors to power the world fleet of freighters.  Imagine the disasters as 50,000 atomic powered ships sink, are abandoned or are overpowered by terrorists worldwide!

    Your posts and arguments are identical to Engineer Poet at RealClimate.  Why have you changed your handle?

    Nuclear power is uneconomic.  It currently costs more for operation and maintenance of a nuclear power plant with no mortgage than to build a new renewable energy plant with a mortgage.  As MARodger points out, it takes 10-20 years to plan and build a nuclear plant versus 2-5 years to plan and build a renewable plant.

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    Moderator Response:

    [BL] Please tone it down a bit, leave the moderating to the moderators, and refrain from speculating about the identities that people may use on other blogs.

  7. Preston Ukra @204,

    The link you quote from, dated 19/8/20, says "nuclear operators will begin the process of gradually raising unit 1's power levels, known as power ascension testing [My bold]" suggesting that to-date the electricity supply is no more than early testing. Indeed, the quote you provide continues to say that Barakah-1 "is expected to enter full commercial operation later this year" so it is not yet properly operational.

    The link also quotes the director general of the World Nuclear Association, saying: "This is a great achievement for all those working at Barakah. Today the UAE joins the growing list of countries choosing nuclear energy as part of their commitment to a cleaner and more sustainable future. What the UAE has learned and achieved should be repeated around the world so that more people can benefit from the value and benefits that nuclear energy offers. [My bold]"  Until some of that 'repetition' starts to appear, the "Pudding Test" which is what I set out @197 will not have been passed by nuclear.

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  8. Dear Reader - I hope you made it this far - 10 posts and a page later - but in post #198 michael sweet at 20:32 PM on 8 August, 2020 stated: "... [the Barakah nuclear power plants, using the APR-1400 designs] would be illegal to build these plants in the USA or EU."

    This is flat out incorrect and wrong. Please draw your own conclusions as to michael sweet's care and diligence in his research and arguments.

    Statement from the NRC on September 19, 2019:

    VI. Issue Resolution A. The Commission has determined that the structures, systems, and components and design features of the APR1400 design comply with the provisions of the Atomic Energy Act of 1954, as amended, and the applicable regulations identified in Section V of this appendix; and therefore, provide adequate protection to the health and safety of the public. A conclusion that a matter is resolved includes the finding that additional or alternative structures, systems, and components, design features, design criteria, testing, analyses, acceptance criteria, or justifications are not necessary for the APR1400 design.

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    Moderator Response:

    [DB]  Ad hominem snipped.

  9. I made a mistake in post #208 - the flipping back and forth between pages really makes it quite hard, but the best I can do - I mean to state post #196 of michael sweet's, not post #198.

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  10. My belief is that  the relevant criteria for an energy grid that does not drive climate change is a low-carbon dioxide emission energy grid.

    Of course, RE being low-carbon energy resources may contribute to a green energy grid effectively. The evidence I use in @198 (IEA data, 2017-2018, my apologies for not noting that) shows that nations which have high penetrations of dispatchable RE, dispatchable nuclear have been able to achieve a low-carbon energy grid.

    I believe the evidence also shows that no nation (as yet, it could happen, but as of yet, it hasn't - so why don't we take the approach we know works?) with high penetrations intermittent RE has been able to achieve a low-carbon energy grid.

    Your response, michael sweet@199, ignores the relevant factor emissions. Your observations might be interesting, if, and only if, the relevant criteria were intermittent RE penetration. These observations are not an argument, because they don't address emissions.

    Should you win the lotto because you are a good person? Irrelevant - you win the lotto because of a random draw that had nothing to do with you except that you bought a lucky ticket.

    France will have more RE - so what? The vital point is France has much lower emissions than Germany NOW, and it appears causal with their use of nuclear power.

    Denmark has 47% RE electricity - so what? The vital point is Sweden has much lower emissions than Denmark, and it appears causal with their use of nuclear power.

    You clearly find the % penetration of RE fascinating. I find neither the % penetrations of intermittent RE nor nuclear interesting. I find the low-carbon countries interesting. Then I ask, how did they do it?

    • Some countries got lucky due to their geography! - geography is not scalable
    • Some countries built nuclear! - scalable - this is a solution to pay attention to
    • There does not appear to be a 3rd answer.

    Even the UK is doing better than poor old Wind_and_Solar_Germany!

                   tot  e&h only - 2017/18 IEA data again
    Germany 8.2  3.6    36% non-hydro renewables; 13% nuclear
    Europe    5.9  2.1    Europe, not the EU
    UK          5.3  1.2    32% non-hydro renewables; 20% nuclear

    The British green energy transition has proven cheaper and more effective than Germany’s because of factors including its use of market mechanisms and its embrace of nuclear power, argues Philip Plickert in an op-ed for the Frankfurter Allgemeine Zeitung.- note: Not a peer-reviewed article!

    You can see from the table that the UK appears similar to Germany, but the real trick is that the UK burns less coal than Germany - that's it - they simply send less CO2 into the atmosphere!

    Also better than Denmark! despite not having whatever % intermittent RE penetration one wishes to rhapsodize over. If the UK stopped burning natural gas, they could get to French or Swedish levels.

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    Moderator Response:

    [BL] repeated declaration of beliefs constitues sloganeering, which is contrary to the comments policy. This has gone far enough.

  11. Preston Urka at 208:

    You claim that the APR1400 reactors are approved for construction in the USA.  It is common for rector designs to be customized for specific installations.  According to this white paper:

    "KEPCO’s winning bid for the construction of the UAE reactors was spectacularly low, about 30% lower than the next cheapest bid. Nuclear reactor design has evolved, but since Korea Hydro & Nuclear Power (KHNP) – a subsidiary of KEPCO – realised that the cost of key improved safety design features would make the APR1400 less competitive, they chose not to include them. Having done so, KEPCO was able to dramatically undercut its competition for the UAE bid, with the Chief Executive of the French nuclear corporation Areva, Anne Lauvergeon, comparing the Korean reactor to a car without airbags and seat belts.⁶" 

    It appears that the Barakah reactors were built without safety features required in the USA and EU.  These safety features were removed from the design to save money.  The approved APR1400 design  has the required safety features.  Nuclear plant builders do not care if their reactors are safe.

    One of the removed safety features is additional reinforcing to resist terrorist attacks.  Who could imagine that terrorists would attack a nuclear plant in the Middle East???  Houthi rebels in Yemen claim they have already shot missiles at the Barakah plant.  Here is an article from NBN media discussing the lax safety at Barakah.

    The fact remains that KEPCO has no additional orders for these reactors.  Apparently, no-one else in the entire world wants to build unsafe nuclear reactors in their country.

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    Moderator Response:

    [BL] Personal opinions deleted.

  12. Preston Urka:

    It is easy to make something look good by leaving out critical information.

    Sweden generates approximately 50% of its electricity from hydropower.  That is a greater share of generation than nuclear.  That is why its carbon production from the electricity sector is so low.  You have deliberately left this out to give the misleading impression that nuclear power is the main reason Sweden has low carbon emissions from electricity.

    You have set up a completely artifical standard to judge electrical systems.  You cherry pick the countries you analize.  You provide no citations to support your ideas.  Since you have no education, training or work experience in electrical systems you are simply sloganeering again.

    Nuclear power has been built for 60 years.  Every nuclear reactor ever built world wide was built with large government subsidies.  Nuclear has never been successful enough to buuild out in large amounts.  Only France has more than 50% of electricity from nuclear power.  France has announced they are going to lower nuclear and focus on renewable energy.  Nuclear power is decreasing because not enough plants are being built to replace old, retiring plants.

    By contrast, renewable energy has only been economic for about 5 years.  It has already been built out enough to provide 10% of world electricity.  Every year more renewable energy is built.  

    There will be some problems as the energy system is changed to completely renewable energy.  Different systems of energy storage than what is used today will have to be developed.  People like you who make false arguments that renewable energy cannot work delay required progress.  

    Nuclear is uneconomic.  There is only enough uranium to power the entire economy for 5 years.

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    Moderator Response:

    [BL] Repeated points deleted. Information about Sweden left to maintain context for following comment by MAR.

  13. Michael Sweet @212,

    The 'fueling' of Swedish electricity generation is more correctly 40% Hydro, 18% Other Renewables, 40% Nuclear, 2% FF.

    These numbers also will inform the comment @210 where a "vital point" was the low Swedish emissions which were presented only as "appear(ing) causal with (Sweden's) use of nuclear power."

    There is also some blather about UK Nuclear @210. 33% of UK electricity is renewables and increasing by the year, while 21% is Nuclear which is set to halve in the next few years. In terms of end-user power, those percentages equate to 5.5% renewable and 3.5% Nuclear. So the UK still remains 90% dependent on FF.

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    Moderator Response:

    [BL] Portions related to comment 210 deleted, as those contents have been subject to moderation..

  14. “LONDON, 19 February, 2020 − Virtually all the world’s demand for electricity to run transport and to heat and cool homes and offices, as well as to provide the power demanded by industry, could be met by renewable energy by mid-century.
    This is the consensus of 47 peer-reviewed research papers from 13 independent groups with a total of 91 authors that have been brought together by Stanford University in California.”


    LINK

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    Moderator Response:

    [RH] No link only comments.

  15. MARodger:

    Your reference is better than mine.  I found on Wikipedia that they shut down a reactor in Sweden in December 2019 and plan to shut down another in December 2020.  Each reactor is about 10% of Sweden nuclear capacity.  That means that in 2020 they will generate about 36% of electricity using nuclear and in 2021 only 32%.  Presumably in a short time they will replace that with renewables.  There are no plans for new reactors.

    The reason given for shutting down the reactors was economic.  That probably means that wind is cheaper than nuclear in Sweden.

    I think we agree that a system that is 58% renewable and 40% nuclear has low carbon emissions primarily because of high renewable content.

    How does the pudding argument apply when people no longer want to keep the pudding they have?

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  16. michael sweet @212

    hydro vs non-hydro renewables

    I stated Sweden has 21% non-hydro renewables; 49% nuclear. (I was not "[making] make something look good by leaving out critical information]). Note that michael sweet @212's source states Sweden has 18% non-hydro renewables (between 18% and 21% I think we can forgive each other for not rounding properly) - we appear to agree!

    I left out hydro because Eclectic @174 chastised me for talking about hydro:

    "Future rivals to Nuclear do not include "hydro" (because relatively little room for large expansion in dams). Similarly not including wave energy or tidal flow or geo-thermal energy ~ which have their own "Pudding" problems."

    I believe (but forgive me if I am wrong) that my argument in @198 specifically includes "dispatchable hydro and geothermal" as being empirical use cases lowering emissions. 

    I acknowledge that Sweden, on the face of it, is not as strong a case as France, but think on this: once having taken advantage of their geographic luckiness by implementing hydro, Sweden makes the most of the balance with nuclear.

    cherry-picking

    I chose several countries to represent the low-carbon, high-penetration dispatchable renewables, several (well, the few) countries/+Ontario to represent low-carbon high-penetration dispatchable nuclear.

    I have invited you to inform this forum and myself of a low-carbon, high-penetration intermittent (or non-hydro if you prefer) renewables country. Cherry-pick to your heart's content! Show us low-carbon!

    lack of citations

    I provide raw data. Better than a citation. Anyone can download and analyze it. Are you claiming that the IEA's data is not valid? https://www.iea.org/countries/

    Are you claiming my analysis is wrong? I have simply looked up the relevant data, copied the chart to a spreadsheet and calculated either fractions or % - excepting E&H per capita emissions. There I took the E&H emissions, divided by the IEA provided population and converted to a fraction. No mystery.

    the argument

    I provide empirical data of real countries with low-carbon emissions. If they were not geographically lucky, it appears due to the penetration (or to include Sweden, the balance of penetration) of nuclear.

    You provide a theoretical construct of Jacobson 2009. Fine. But empirical results beat theoretical suppositions. Again, show us your cherry-picked low-carbon, high-penetration intermittent renewable empirical example. Shut me up with a HAH! in your face Preston!. Or, keep on with 'it could be done', 'it might be done', 'it has possibilities' .....

    the wrong argument

    Again your argument is (very, very brief description) 'nuclear bad and RE upcoming'. What you don't mention in all of @212 is about the low-carbon abilities of intermittent RE.

    (I paraphrase michael sweet @212 here for brevity). Let me (for the sake of this post only) agree with your points:

    • "Nuclear is uneconomic" - ok, but it reduces emissions.
    • "Nuclear needs subsidies" - ok, but it reduces emissions.
    • "Only France has 50%" - ok, but it reduces emissions.
    • "France is moving to renewables" - ok, current nuclear reduces emissions; will France reduce emissions further by moving to renewables?
    • "Renewables are cheap" - ok, but intermittent renewables don't appear to reduce emissions much.
    • "Renewables are growing" - ok, but intermittent renewables don't appear to reduce emissions much.

    Originally I wrote low-carbon potential of intermittent RE - yeah, it has lots of potential. Where is the empirical evidence?

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    Moderator Response:

    [BL] More repetition deleted. Any further discussion need to provide a new perspective.

  17. the false argument

    "People like you who make false arguments that renewable energy cannot work delay required progress." - michael sweet @212

    1. I will try not to take your comment that I make false arguments too seriously.
    2. I do believe that intermittent RE can 'work' - but my definition is different from Jacobson 2009.
      • Wind and solar PV will provide a significant (up to c.f., so ~30%, which is significant) amount of electricity.
        • I will even go so far as to say that Jacobson 2009 is not completely hopeless technologically, but will never succeed economically or politically due to the simply bone-crushing costs it imposes. Emulating France is just too easy for financiers and politicians (assuming they take emissions seriously)
      • Nuclear will provide the rest of electricity. (or the world will use high-carbon natural gas)
      • Nuclear will provide process heat for industry. (or the world will use high-carbon natural gas)
      • Nuclear will provide synthetic fuels for transport and agriculture. (or the world will use high-carbon natural gas)
    3. I believe intermittent RE is OK, per Lion Hirth, at penetrations up to their capacity factors.
    4. I do not believe that intermittent RE can meet demand load without:
      • bulk storage (i.e. cycle times on the order of days and weeks - vs the ancillary roles now provided)
      • demand management
      • some significant geography or population demonstrating intermittent RE empirically
    5. But, I do not believe bulk storage is possible. Not at the scale we're talking about. A 24 GWh pumped hydro station is one thing. A global system with storage on the order of TW-hours is another.
    6. But, I believe demand management can solve only 10-15% of the puzzle.
      • We don't have an electricity grid just because.
      • We have an electricity grid to support the whims and desires of the humans using it.
    7. I believe that laymen (and politicians):
      • confuse the marginal costs of electricity with the average costs of electricity
      • (incorrectly) equate intermittent energy with dispatchable power
      • (incorrectly) extrapolate a single plant's cost to system cost
      • and thus to these laymen/politicians nuclear appears expensive. Once they get their heads on right, or the implementation costs of nuclear come down such that the above are more obvious, and if low-carbon (vs. RE penetration) is the goal - countries will emulate France - low-carbon, dispatchable power with low average system costs.
    8. Lastly, I do not believe in betting based on optimism. The entire planet is at stake - what do the rest of us get if your supposition is wrong: "Different systems of energy storage than what is used today will have to be developed." - michael sweet @212 - If you (the reader) answer YES to any of these questions below, then you are either honest and reporting the past (and thus must be lying) or are lying and just predicting the future. At best a MAYBE - we, in the present are incapable of knowing the future. Again, you want to make the bet - what are the payoffs?
      • Will we suddenly make some new scientific breakthrough on gravity? (pumped storage, mine-shaft storage)
      • Will we suddenly make some new engineering breakthrough on friction? (compressed air, flywheels)
      • We know the charges, masses, densities, and electrochemical potentials of all the elements and all the smaller molecules (and larger just means lower specific density). Are we going to make batteries, not 2x better, but 10x or 100x better?
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    Moderator Response:

    [BL] sloganeering deleted.

  18. @217 - here are examples of plant costs vs system costs

    Feb 2016 - re-dispatch-costs-german-power-grid

     

    Some researchers argue that new north-south connections would never have enough capacity to absorb the growing wind power generation in the north and the decreasing conventional capacity in the south – where many nuclear power plants will go offline in the next seven years.

    Question: Why are these costs not allocated to the cost of Wind? Nuclear, as above, does not need these transmission lines. Wind (as a plant) costs less. Wind (as a system) costs more.

    Feb 2019 - German grid firms see extra costs to meet renewable power target

     

    Total spending of 70 billion to 79 billion euros over 12 years would be shouldered by consumers via higher grid fees, which account for about a quarter of their electricity bills.

    Between a quarter and half of power demand in southern Germany will have to be met by renewable generation in the north, where plants now generate double the north’s needs.

    Observation: If Germany were using nuclear in the south, the transmission would not be built (saving the 70-79 billion Euro); and excess wind would not need to be built in the north (i.e. a higher return on assets).

    July 2019 - just 35 wind turbines were build with an output of 231 megawatts in 6 months

    Hardly any new wind turbines were built in Germany in the first half of the year. Turbine makers call it a “punch in the gut of the green energy transition” and blame environmentalists.

    Just 35 wind turbines were build with an output of 231 megawatts. ... "a decline of 82 percent"

    But when in 2021 thousands of wind turbines come to the end of the 20-year subsidy period of the Renewable Energy Act, more wind turbines will be demolished on balance than new ones will be added, the wind industry fears.

    Observation: Environmentalists don't like wind now and the wind industry needs enormous subsidies or they will take their marbles home (my sparring partners on SkS firmly disapprove of subsidies).

    michael sweet/MA Rodger, did not one of you mention how fast, fast, fast the wind industry is and how it is only growing? - I take the decline of 82% wind, not as the fault of wind, and not due to the success of nuclear, but as proof of the value of the incentives governments set up. If the market favors wind, wind will be built. If the market favors nuclear, nuclear will be built. The difference is, at the system level, nuclear has been empirically been shown to reduce carbon emissions. Wind has only been shown to do so at the plant level, and Jacobson and his fellow travellers extrapolate that to the system level.

    August 2019 - Grid expansion in is gaining, but not enough for intermittent RE

     

     

    ... the integration of renewable energy is improving. [However, _coal_ (note Preston addition)] power stations in southern Germany, which remain unused during the summer months, are recommissioned in the winter.

    The commissioning of the Thüringer Strombrücke ... has helped significantly relieve the pressure ... 190-kilometer-long .... 5 gigawatts (GW) ........ However, this has not done much to reduce the overall costs of the grid interventions.

    [TSO] estimate that by 2030, the price tag on grid expansion will clock in at 62.5 billion euros.

    But when the last nuclear power plants are taken off the grid in late 2022, the north-south divide in generation capacity and electricity consumption will become even more pronounced than before. The Federal Network Agency estimates that demand for reserve capacity will then reach a record high of 10,647 MW.

    ... authorities have ... prohibited ... decommissioning of 27 power stations. The operators [want to retire] 110 plants ,,, capacity of 22,000 MW ... because ... operation is no longer financially viable.

    Question:

    • Why are these costs not allocated to the cost of Wind? Wind drives it (or lack of wind) and 
    • Do you begin to see the scale of support for Wind?
      • 110 assets are useless, but authorities want at least 27 dud assets kept - it is not because Wind is so great!
      • Do you see that the operators can't support costs when politicians confuse marginal and average costs?
    • Even a 5 GW transmission line (yes, that is a truly big one!) does not reduce costs much.
    • Do you see the Germans could avoid a) the cost, and b) the coal if they just kept the nuclear plants open?
    0 0
    Moderator Response:

    [BL] Sloganeering deleted

  19. michael sweet @215

    Following up to my point in @216 (hydro vs. non-hydro)

    "I think we agree that a system that is 58% renewable and 40% nuclear has low carbon emissions primarily because of high renewable content." can also be read as:

    Sweden has low-carbon emissions (in electricity) primarily due to 80% dispatchable low-carbon generation, assisted by 18% intermittent low-carbon generation, for a total of 98%.

    It is not the RE% penetration that determines emissions; it is the carbon content generation that determines emissions.

    0 0
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  20. Preston Urka at 216:

    This is another post where you state your unsupportted ideas.  Since you have no training, experience or education in nuclear power or power systems this post is entirely sloganeering.  You are simply cherry picking data to fit your arguments.  If your arguments had any weight you would find some references to support them.  This is a completely unscientific post.

    At 217: Every point you make is started "I believe".  You have only one reference from 2012.  Experience in wind power worldwide since 2012 shows that your reference is incorrect.  Once again you are simply sloganeering.  This is a completely unscientific post.

    218: Here you actually have citations!!!  Unfortunately, all are to news articles (including one at WUWT!!!) and not peer reviewed articles.  You primarily discuss grid expansion costs.  Fortuantely, this is covered in the peer reviewed literature cited upthread.  If you had carefully read the background you would know that grid expansion typically costs 10-15% of total costs.  This turns out to be a reasonable cost.  Here is another link to a peer reviewed paper that discusses grid costs.  Nuclear supporters used to make this argument several years ago until it was proven incorrect.  Please try to catch up to current knowledge.  Citing outdated papers and debunked arguments makes you look bad.

    At 219: The point is that your claim that low carbon intensity in Sweden is due to nuclear was deliberately false.

    At 220: Everyone wants to reduce the carbon intensity of economies.  The peer reviewed literature indicates that the best way to achieve this goal is by building out renewable energy as fast as possible.  This link contains the abstracts of 47 papers that describe how to provide 100% of energy to the entire economy world wide using renewable energy.  They come from 13 different research groups with 91 different authors.  This list demonstrates a consensus among energy system researchers that renewable energy is the way to go. (Hat tip to Postkey.  You need to describe why your link is useful to be compliant with the posting rules.)

    Your claims that renewable energy cannot supply 100% of world power are supported only by your opinion as someone who has no education, training or work experience in power systems and is completely informed by reading on the internet (and who cites WUWT as a reliable source).  Coonstantly repeating your unsupported opinion is sloganeering.

    Please cite one paper that suggests it might be possible to supply even half of world energy using nuclear power.  Such a paper does not exist.  According to Abbott 2012, it is impossible to supply a significant amount of world energy (more than 5%) using nuclear power.

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    [BL] Responses to moderated comments deleted

  21. Daniel Bailey:

    On the forced variations thread at RealClimate a nuclear argument like the last 30 posts above has been going on for several years.  Unsupported claims and the opinion of people informed only by their reading on the internet are constantly repeated month after month. 

    I do not like to have these post at SkS go unanswered.  At some point we need to say that everyone has had their say and given their references and leave it alone or the thread will go on forever.  If references were required and repetition not allowed the argument would soon end since there are few papers to support the nuclear argument.

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    Comments should avoid excessive repetition. Discussions which circle back on themselves and involve endless repetition of points already discussed do not help clarify relevant points. They are merely tiresome to participants and a barrier to readers. If moderators believe you are being excessively repetitive, they will advise you as such, and any further repetition will be treated as being off topic.

  22. michael sweet - it seems no discussion of economics: the value of dispatchable power vs intermittent energy, or the distinction between average cost and marginal cost, or the distinction between the cost of a single plant vs a total grid system - these are simply not allowed.

    Since this is outside the permissible discussion topics here, I just won't make any further economic arguments for nuclear.

    Post @202 is not about using waste heat to power industry, but about using heat (as in primarily, skipping the conversion to electricity and back again).

    An example of using waste heat to power industry is Palo Verde used to treat sewage.

    "It is uneconomic to run since a reactor requires many more operators than a traditional ship. Military vessels do not care about the extreme cost." - what, a bald statement without a citation? I might give you that the military is insensitive to cost, but you have not presented evidence for this conclusion. Ditto your _belief_ that this is a tempting terrorist target.

    Of course, there are exceptions: a rather opinionated, belief-ridden statement "Nuclear power is uneconomic." from @206, without citations or calculations lives on. Taking construction cost and time-to-build, you put it through your arithmetic machine and end up with ... I mean it looks like you have a point, but one does have to keep close a bunch of pre-conceived notions about economics and power grids and then finish the thought for you for an actual conclusion to be reached.

    To have the privilege of discourse where almost any thought is censored, well ... if that is the site you guys want, you are welcome to it.

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  23. Preston Urka:

    According to your reference, "The facility evaporates water from the treated sewage of several nearby municipalities to meet its cooling needs."  That means treated sewage is used to cool the power plant.  The power plant is not used to treat the sewage.

    With current shortages of water in  Arizona they would drink the treated sewage instead of using it to cool a power plant.

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  24. Preston Urka - post 202 

    ..claims nuclear process heat could be supplied from 250 to 1200 degrees C, whereas solar can only manage to ~650 C. 

    Current lightwater reactors operate around 330C, which is too low for most industrial use. Waste heat has been used for district heating though, for example in Switzerland from the Beznau reactor, in Czechia, and in Russia.      

    LINK                                                                     

    Simpler, lower pressure reactors operating at only about 90C and used solely for district heating are being built in China, and could make a big difference to winter air quality in cities like Beijing. LINK

    The BN350 reactor in Kazakhstan operated for 26 years providing both electricity and desalinated water. ( It closed mainly because, after the Soviet Union  broke up, Kazakhstan could not afford the fuel.) This was a sodium cooled reactor, and so could operated at 200C hotter than a light water reactor. Bill Gates' Terrapower sodium-cooled reactor company has recently developed a variant on their design which would directly heat molten nitrate salts, as used in Concentrating Solar Power plants. This would give about the same temperature salt as solar, but with the advantages of not needing to be in a desert, not needing natural gas to heat the boilers up in the morning, and giving 24/7 heat regardless of cloud or season.

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    [RH] Shortened and activated links.

  25. Please note, that we added an important update to this blog post today. We hope that it clarifies what we are looking for in case somebody would like to write an article about nuclear energy.

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  26. Apparently the NRC has approved the NuScale modular reactor design.  They are set to build a reactor on the Idaho Falls DOE site.  A pro-nuclear article in Forbes said:

    "NuScale is building its modular SMR on the DOE’s Idaho Falls site and has a contract to sell the electricity to a consortium of rural electric cooperatives, two of which recently dropped out because of spiraling cost projections. This is dampening SMR enthusiasm and attention is returning to the large reactors of 1,000 MWe and above."

    Apparently even nuclear supporters are losing enthusiasam for small modular reactors.   Nuclear supporters move the goal posts again because the current designs have failed.

    The Forbes article supports a molten salt start-up.  As I understand it, the alloys necessary to build the valves in a molten salt reactor have not been invented yet.  Perhaps they have a supply of "unobtainium".  A major cost savings was the claim that a containment structure is not needed.

    This peer reviewed article finds that countries that build out nuclear power plants do not reduce carbon pollution while countries that build out renewable power plants reduce carbon polllution.  If nuclear is built out than the amount of renewable energy is reduced.  It is only a correlation study, more research will be necessary to confirm the conclusions.

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  27. MIchael,

    I searched valve issues for MSR and found mostly publications centered around the freze valve problem,  but nothing specifically relating to the availability of alloys up to the task. Can you be more specific?

    As for myself, I believe that there is immense potential in the TWR model, and I find it hard to understand that a prototype would not already be underway in the US. If construction times can be kept at the necessary levels, it is the only solution that I know about with the potential to solve the energy problem of civilization at the short and medium term. If this was given the public attention it deserves, working plants could be generating commercial electricity even before ITER would start delivering useful data.

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  28. Philippe Chantreau:

    Thank you for providing a peer reviewed study to support your question.

    Your reference is a summary of current knowledge of "freeze valves".  The first paragraph states:

    "Reliable mechanical valves that can withstand the corrosive and high-temperature conditions in Molten Salt Reactors (MSRs) have not yet been demonstrated. In their place, freeze valves (sometimes called freeze plugs) represent a unique nuclear design solution for isolating salt flow during operations." my emphasis.

    As I stated above, no alloys to manufacture control valves are known that can withstand the extreme heat, corrosion and radiation fields in an MSR.  Reactor designers are looking for other ways to control liquid flow.  A freeze plug is a system of a thin pipe where a plug of solid salt is allowed to form.  This pipe has to have complicated heating and cooling systems.  It takes about 15 minutes to form the plug, during which the molten salt cannot be moving, and about 15 minutes to thaw the plug.  Most of the small amount of known data and designs about freeze plugs are from the 1960's.  Apparently recently MSR developers have started to investigate freeze plugs again because they have been unsuccessful in finding alloys to build mechanical valves.

    Freeze valves are apparently not used in any existing chemical or nuclear processes.  Therefore the knowledge of their manufacture, use and failure modes is rudimentary.  They are complicated and have many failure modes compared to normal mechanical valves.  They open and close very slowly in emergencies.  The size of pipes used is restricted.  Test valves have suffered catastrophic failure.

    The conclusion of the paper you cite says:

    "Especially because the technical maturity of all solutions to isolate salt flow is so low, it will be important for MSR stakeholders to advance the state of knowledge surrounding freeze valve systems, and other alternatives under consideration, through a combination of physical tests, computational simulations, and design-related studies." my emphasis

    I conclude that it is currently unknown how to control the flow of liquid salt in an MSR.  It may be possible to develop a solution but it will take significant research, time and testing.  Designers tried to avoid freeze plugs because they have many undesirable properties.

    Proponents of MSR's have many significant problems that they need to resolve, including the fact that they do not know how to regulate the flow of liquid through the reactor.  It will take many years of research to solve these issues, if they can be solved.  Suggestions that a design that can be built exists or will exist in the near future are deliberately false.

    Many additional problems exist for MSR's.  The designs are complicated and only the nost optimistic proponents envision that they can compete with renewable energy in the foreseeable future.  If a reactor is ever designed, there will still not be enough uranium in the world to provide more than a small amount (less than 5%) of energy to the grid.

    I think it is a waste of money to attempt to develop a reactor where a pilot plant cannot be designed in less than 10 years.  It would take at least 5 years to validate the design and then 10 years to build the first commercial reactor.  You are looking at 2050 or later for the first commercial reactor which is too late.  The uranium problem has no proposed solutions (thorium has additional problems of its own).  The money would do much more good used to build a wind or solar farm.

    Your reference is very long and technical.  I only read about half of it in detail.

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  29. Philippe:

     The TWR reactor you link is a sodium cooled reactor and not an MSR.  It is confusing when you discuss MSR's and sodium cooled reactors in the same post.  Are you aware that TWR reactors are not MSR's?  Sodium cooled reactors have their own, different, set of problems compared to MSR's.  Sodium is extremely corrosive and is flammable in both air and water.  

    The article you link is a progress statement from TerraPower LLC, a company associated with Bill Gates.  They claim they are making progress with their design but do not have a buildable design yet.  When they have a buildable design we can discuss their future prospects.

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  30. I was not under the impression that the 2 designs were similar, perhaps I should have conveyed that better. To my defense I can say that at least I mentioned the 2 different types in 2 different paragraphs... :-)

    I had not realized that quite a bit of tension seems to have developed in this thread over time, but had no intention to strike any nerve.

    I am quite familiar with Terra Power; the article I linked, however, is of a much more detailed and informative nature than the basic info available through the Terra Power website. Especially interesting is the the radiation induced swelling issue, which does require special alloys, but the paper claims to have a workable solution with the HT9 alloy.

    I understand that the classic objections to "new" nuclear designs (there isn't one working, economics have not been demonstrated, time to be online, etc) do apply to this one as well. Nonetheless, the advantages of being able to use spent fuel, leaving depleted uranium as a by-product, and the safety features inherent to the design deserve consideration. Not to mention that a 600 MW plant operating as baseload is nothing to sneeze at. If it can be scaled up, as projected, to 1200 MW, I'm imagining how many coal fired power plants can be replaced by carbon free operations (free beyond, of course, material production, initial construction etc), and I find it very appealing. As far as I know, they do have a buildable prototype design, which was going to be started in China but everything fell by the wayside due to the current US administration policies. I find it shocking that a prototype had not been started in the US before 2016.

    This is not something to be discounted only on the basis of traditional objections, ideological opposition, or any other preconceived ideas. It offers tremendous advantages if it works as expected. It can produce, and deserves, a prototype and if it turns out as good as projected, it is, in my opinion, a very good solution.

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  31. Philippe Chantreau,

    When I was young I believed the promises of nuclear engineers.  After 45 years of following nuclear power I no longer trust their paper designs and promises of safe reactors.  If they ever build a pilot plant we will see if their scheme actually works as they claim.  Upthread I cite the French Nuclear Regulatory Agency which does not see safety improvements in these new designs and the Union of Concerned Scientists who fear that false claims of inherent safety will lead to removal of expensive safety features in reactors.  There are reasons that they have not yet built even a test reactor or pilot plant after 13 years of work.

    I note that NuScale is losing customers now that they are actually trying to build their reactors.  The cost is too great.  It is not clear to me if their reactor price has increased or if renewable energy is now so cheap that they cannot compete.  Probably both.

    Nuclear power is uneconomic.  It takes too long to build.  Even if they achieve their goals it will be 2050 before TRW reactors are ready for a large scale buildout.  I see no reason to believe that reactors with complicated double cooling systems can control the problems of using liquid sodium in a cost effective manner.  They have not addressed the problems of Abbott 2012.  I am especially concerned about the extensive use of rare materials.

    In a renewable energy world baseload power is very low value.  Peak power on windless nights is most valuable.  Current baseload plants are dinosaurs.

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  32. Recommended supplemental reading: 

    Regulators have approved designs for 12 small reactors to be built in Idaho, but opponents say the project is dangerous and too late to fight climate change.

    Small Nuclear Reactors Would Provide Carbon-Free Energy, but Would They Be Safe? by Jonathan Moens, InsideClimate News, Oct 21, 2020

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  33. “Could Russia Floating Nuclear Plants Change World Economy?
    By F. William Engdahl
    25 November 2019

    While the EU and United States have all but abandoned nuclear energy as a future power source, with almost no new reactors being built and existing ones being decommissioned, Russia has quietly emerged as the world’s leading builder of peaceful civilian nuclear power plants. Now the Russian state nuclear company, Rosatom, has completed the first commercial floating nuclear plant and has successfully towed it to its ultimate location in the Russian Far East where access to power is difficult. It could transform the energy demands of much of the developing world, in addition to Russia. An added plus is that nuclear plants emit zero carbon emissions so that political opposition based on CO2 does not apply .“

    www.williamengdahl.com/englishNEO25Nov2019.php

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  34. 'In a renewable energy world baseload power is very low value. Peak power on windless nights is most valuable. Current baseload plants are dinosaurs.' At least three nuclear designs going through certification - the Bill Gates/Terrapower sodium cooled reactor, the Canadian Terrestrial Energy molten salt graphite design ( based on the Oak Ridge Molten Salt Reactor Experiment ), and Moltex (an innovative fast reactor using plutonium chloride salt in fuel tubes similar to those of current reactors) - propose directly heating nitrate salts, as used in concentrating solar power plants. This would enable the reactor part to make heat 24/7, at ~ 500 megawatts, but store it to make power on demand at 1000 or 1500 MW, with only an additional turbine or two. This would integrate well with wind, which usually manages a 30-40% capacity factor. This would be much better than the current scenario, where part time wind, backed by natural gas, is undercutting baseload nuclear. Overall emissions rose after the closure of Vermont Yankee and San Onofre. They will certainly go up again when Indian Point, near New York, closes. Andrew Cuomo, governor of NY state, admitted that the closure of upstate reactors would lead to more gas being burnt, but would not relent on forcing the Indian Point reactors, which provided about a third of the city's power, to shut. They had been in the process of getting a twenty year licence extension, and could probably have had a further twenty years, as have several similar power plants.

    https://www.electricitymap.org/zone/US-NE-ISNE?wind=false&solar=false

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  35. John O'Neill:

    According to this World Nuclear News article from September 2020, the Terrapower sodium cooled reactor you refer to has not been submitted for certification.  They hope to start commercialization by the end of the decade.  Likewise Canadian Terrestial Energy is a start up with a paper design and little else.

    Can you provide references that support your claim these reactors are more than paper designs?

    The storage of the Terrapower reactor would only raise output less than 50% for 5 1/2 hours.  That doesn't sound like cheap storage to me.  Both these designs have signficant problems to deal with for example: liquid sodium reactors have chronic sodium fires and molten salt reactors have no materials to manufacture valves.

    Since nuclear power plants have to be run full out all the time to be economic they do not fit into a renewable system.  The claim that with storage the reactors fit well with wind is simply propaganda from the industry.  In addition, they are too expensive to build and run and take too long to build.  Even the builders of the reactors you mention do not expect their designs to be buildable before 2030 best case.  We need to change over to renewable energy before those reactors will be ready.

    When a nuclear power plant is shut down it takes time to build replacement renewable energy.  If we really try to build out wind and solar there will be a substantial decrease in carbon emissions in a short period of time.  As more and more renewable energy is built out emissions have already started to decrease. 

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  36. 'The storage of the Terrapower reactor would only raise output less than 50% for 5 1/2 hours.'

    That would be adequate for demand cycles on most grids, where peak power, as a rule, is on the order of 50% higher than base. Remember, it's going from ~ 60% to 150% - at night much of the heat production goes to storage. Solar thermal storage has pioneered the technology, but has nowhere near the capacity factor -even in deserts, in summer - to match the reliability of nuclear.

    The BN600 and BN800 in Russia seem to be operating without any leaks or fires - unlike some of the new grid storage battery plants, which, although nowhere near the gigawatt-day scale, or the price point, to be able to power a country through a cloudy, windless spell, are claimed to be ready to rescue part-time power sources from their role as sidekicks to the fossil industry.www.spglobal.com/marketintelligence/en/news-insights/latest-news-headlines/burning-concern-energy-storage-industry-battles-battery-fires-51900636

    'If we really try to build out wind and solar there will be a substantial decrease in carbon emissions in a short period of time.' That's something I haven't seen, though I rather obsessively scan www.electricitymap.org/zone/JP-KY?wind=false&solar=false for examples of it. Today, for the first time I've seen, Kyushu got well below 100 grams CO2 per kilowatt hour - but only briefly, at midday. For most of the 24 hours, it was three or four times as much. Areas that have invested mostly in nuclear - or hydro, when available - are routinely well below that mark, 24/7. 

     www.electricitymap.org/zone/CA-ON?wind=false&solar=false

    www.electricitymap.org/zone/FR?wind=false&solar=false

    www.electricitymap.org/zone/SE?wind=false&solar=false

    ( I'd have added Switzerland, but lately they've gone above the 100g/kwh mark most of the time. I'm not sure if it's because they've been closing reactors, or because, like here in New Zealand, they're having a dry hydro year. Either way, it's not a good augury for the country's goal of nuclear free, zero carbon, by 2050. Part of it could also be that they're importing a lot of power from Germany, which dirties their average.)

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  37. John ONeill,

    The terrapower plant storage may be useful for short time use but for seasonal storage it will not supply anything.

    Fortunately, we do not need to rely on your personel observations to determine whether nuclear plants or renewable energy lead to lower  carbon emissions.  This study: Differences in carbon emissions reduction
    between countries pursuing renewable electricity
    versus nuclear power
    Sovacool et al 2020 studied just that.  The complete abstract states:

    "Two of the most widely emphasized contenders for carbon emissions reduction in the electricity sector are nuclear power and
    renewable energy. While scenarios regularly question the potential impacts of adoption of various technology mixes in the
    future, it is less clear which technology has been associated with greater historical emission reductions. Here, we use multiple
    regression analyses on global datasets of national carbon emissions and renewable and nuclear electricity production across
    123 countries over 25 years to examine systematically patterns in how countries variously using nuclear power and renewables contrastingly show higher or lower carbon emissions. We find that larger-scale national nuclear attachments do not tend
    to associate with significantly lower carbon emissions while renewables do. We also find a negative association between the
    scales of national nuclear and renewables attachments. This suggests nuclear and renewables attachments tend to crowd each
    other out" my emphasis

    Countries that build nuclear as a group do not reduce carbon emissions.  Countries that build out renewables do.

    You look at France, Sweden and Ontario, Canada.  Engineer Poet on Real Climate also likes those two countries and that state.  Perhaps looking at Uruguay  100% renewable mostly wind. 

    North east Brazil  95% renewable, mostly wind. And

    Bornholm, Denmark  100% renewable, no hydro.

    These examples are from your source.  All have renewable energy systems.  You are just not looking.  It appears your claim at 236 that "I obsessively scan for examples of it" is false.  It took me less than 5 minutes to find these examples.  I note that your links all say "wind=false and solar=false".  Perhaps you are using the incorrect search terms.

    Sweden closed 2 of their 8 remaining nuclear reactors in the last 18 months.  During 2020 their remaining reactors only ran 60% of the time.  They are rapidly bulding out wind and have no plans to build more nuclear.  The nuclear plants cannot compete on the local grid with hydro and wind.  Although they do not currently have plans to shut down the nuclear plants (they spent a lot of money refurbishing them 5-10 years ago), the handwriting is on the wall that when planned new wind is installed there will be no economic way to use the nuclear plants.  Hydro will provide more than enough backup when the wind does not blow.

    France is planning to shutter 14 nuclear plants in the near future (they also closed two last year) and install renewables.  Ontario's nuclear plants are old and they are installing wind.

    I noticed you forgot links to descriptions to the Russian nuclear reactors.  According to Wikipedia, the BN600 has had 27 sodium leaks resullting in 14 fires.  As much as 1000 kilos of sodium leaked.  Apparently, in recent years they have leaks under control.  Construction for the BN800 was started in 1983 and completed in 2016. source The BN 600 runs only 70% of the time because of required maintenance.  Both reactors have three complicated triple part cooling systems to isolate the radioactive sodium coolant from water since sodium is flammable in water.  These reactors cost even more to build than normal reactors.  They will never be economic.  No more are planned worldwide.

    Renewables have only been the cheapest energy for a few years.  Comparing directly to nuclear, a 60 year old, mature technology, is stupid.  After 60 years nuclear generates less than 5% of world energy.  Little is being built.  In 2020 more than 80% of new electrical capacity added world wide was renewable.  Because renewables are now cheapest, they are the most installed.  For much of the non-renewable energy installed in 2020, construction  was started when renewables were more expensive.  In the future renewables will dominate all new construction.

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  38. 'Countries that build nuclear as a group do not reduce carbon emissions. Countries that build out renewables do.'

    By restricting his study to emissions reductions over the last 25 years, Sovacool omits the period when nuclear build massively replaced oil and coal power generation. The legacy plants left over from this period are still making far more power than wind and solar, and most of them are light water reactors, which have been licensed to eighty years in the US, and should be in most other places too.

    '.. looking at Uruguay 100% renewable mostly wind.

    North east Brazil 95% renewable, mostly wind. And

    Bornholm, Denmark 100% renewable, no hydro'

    Uruguay gets 60% of its power from hydro. It also resembles Denmark, in being a small country in between two much larger ones, to which it can export its surplus wind, and from which it can import during calm periods. North East Brazil also has quite a lot of hydro, and can import much more from North Brazil when needed. Just now it is getting 43% from wind, the rest from local or North Brazil hydro. I'd also note that it's running at about 10 to 12 GW for a population of 50 million people, well below the level associated with places with a high human development index, and that without replacing fossil fuels for uses like transport and industry. Bornholm has no hydro, but imports up to 95% of its power from Sweden at times, usually mostly hydro and nuclear. ( Sweden has wind turbines too, but when they're not spinning in Bornholm, they're usually not doing much on the mainland either.) Bornholm's power emissions would also be much lower if it wasn't burning so much biomass.

    'Sweden closed 2 of their 8 remaining nuclear reactors in the last 18 months..... Hydro will provide more than enough backup when the wind does not blow.

    Sweden provides clean power not just for itself, but also for Denmark, Germany, Finland and the formerly Soviet Baltic countries. It's likely that if they close their nukes, these other countries will have to burn more fossils, even if Sweden doesn't. Greta Thunberg recently posted a link to an article describing how much damage biomass harvesting is doing to Sweden's forests. Nuclear is a much less land-hungry, and lower carbon, alternative for power independent of weather conditions.

    www.theguardian.com/environment/gallery/2021/apr/16/forests-felling-swedens-ancient-trees-biodiversity-sami-environment?fbclid=IwAR3xUJygb_iD4qHOsydbG__83m1g2rxpt41B3AujkO9DYQCq1dYphFmudeg 

    'France is planning to shutter 14 nuclear plants in the near future (they also closed two last year) and install renewables.' -Macron closed the two reactors at Fessenheim, which had received 2 billion Euros worth of upgrading in the last few years, making them effectively the country's most modern plants. This fulfilled a campaign promise by his predecessor, President Hollande, whose Energy Minister (and former lover), Segolene Royale, had offered to donate them to Elon Musk to turn into Tesla car factories. She also vowed to build a thousand kilometres of solar roadways. Macron has subsequently stated that further reactors will not be closed if the result would be a rise in emissions. It certainly would be.

    'Ontario's nuclear plants are old and they are installing wind.' Ontario is refurbishing its heavy water reactors in the Darlington and Bruce plants, and the Canadian government is actively promoting new Small Modular Reactor designs. The province has not tendered for any new wind since 2014.

    'I noticed you forgot links to descriptions to the Russian nuclear reactors. According to Wikipedia, the BN600 has had 27 sodium leaks resullting in 14 fires...The BN 600 runs only 70% of the time because of required maintenance.' In its early years, the BN 600 did suffer a number of leaks, but since this was expected, it had been given three independent cooling systems, each capable of 50% of the thermal load, so that any one could be worked on with the reactor still operational. The BN 800 had no leaks. Operational status of the BN 600 over the last six years averaged 85.1 % capacity factor - roughly double a wind plant. https://pris.iaea.org/PRIS/CountryStatistics/ReactorDetails.aspx?current=484

    'Both reactors have three complicated triple part cooling systems to isolate the radioactive sodium coolant from water since sodium is flammable in water.' Bill Gates' sodium reactor directly heats nitrate salts, for energy storage.

    'These reactors cost even more to build than normal reactors. They will never be economic. No more are planned worldwide.' - Apart from the one Gates' company is developing, there's one being built in India, and one in China. Nasa is also working on a similar design for use in space, and a company called Oklo has just received the first US licence for a non-light water SMR. Two other designs are under licence review in Canada. With no water adjacent to the hot fuel, they should be able to run much hotter than LWRs, greatly increasing thermal efficiency, while avoiding any danger of a steam explosion, and thus most of the cost of containment.

    'After 60 years nuclear generates less than 5% of world energy.' -In 2019, wind made up 2.2%, and solar 1.1%.

    'In 2020 more than 80% of new electrical capacity added world wide was renewable. ' -Since wind and solar have the second lowest and the lowest capacity factors of any generation source, their contribution to world energy was much lower, proportionally, than their increased nameplate capacity.

    'In the future renewables will dominate all new construction.' In places such as Italy and Spain, solar installations boomed till they reached between five and ten percent of total power generation, by which time the costs, and the stresses to reliable power supply, led to a dramatic decline in growth. Japan's solar installations peaked in 2015, at which point they were generating 3.5% of the country's power ( Wikipedia ). Since then, yearly additions have been gradually declining, even though prices are still falling. In 2019, solar made 7.6% of electricity generated there, still far below the third from nuclear pre-Fukushima. Most of the shortfall since then has been from increased coal and gas imports. Japan has also recently suffered massive power spikes in winter, as LNG availability fell during cold spells. The government wants to reopen more reactors to reduce power costs. It would also reduce emissions - a win-win.

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  39. Quoted @237 & 238 - "After 60 years nuclear generates less than 5% of world energy."  The 2019 nuclear contribution to world primary power was 4.3% according to the BP Review but OurWorldInData shows nuclear did manage 6.5% back in the 1990s, so after 30 years. Since that time nuclear has failed to keep up with demand, with output stalling at 2,600TWh/yr since 2005. Given the need for carbon-free energy, the failure of nuclear to deliver can have no excuses.

    Meanwhile OurWorldInData shows the renewable contribution continues to grow, with solar & wind reaching 2,400TWh/yr in 2020, an increase of 14% on 2019. 

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  40. John O'Neill,

    The Guardian article you cited is about Sweden's forestry practices and has nothing at all to do with its energy generation, or policies. It does not support any part of your argument. The "article" (mostly a succession of pictures with captions) mentions the country's export of paper, pulp and sawn timber, it does not allude to energy policy or energy from biomass at any point. It does make a good point that the forestry practices are less than ideal. Similar practices exist in the US and Canada, unfortunately.

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  41. Philippe Chantreau - I was actually looking for another item that Thunberg linked to. The relevance is that nuclear is always contasted with 'renewables'. In theory, at least according to Mark Jacobson's 'Solutions Project' scheme, that would be over 90% wind and solar - for everything. In practice, at present, it also covers the burning of various forms of biofuel and biomass. These are welcomed by some W & S advocates as covering the obvious gaps in energy supply from weather, and also by owners of fossil fuel businesses, who can claim various percentages of emission reduction, by putting corn ethanol in petrol, woodwaste in coal feed, or biodiesel in fossil diesel. The island of Bornholm, for example, cited by Michael Sweet as 100% renewable, uses farm waste for power when the wind drops. The website we both referred to lists biomass as having CO2 emissions of 230 grams per kw/h, versus 45 for solar, 11 for wind, and 12 for nuclear. 

    We have history for societies running on 100% renewable energy. In Britain in 1700, for example, there were about five million people, there was a desperate shortage of wood, and so eventually coal extraction led to the steam engine and the industrial revolution. Now there are 60 million people on the same islands, with much higher levels of energy use. Even just to cover steel manufacture, there is no way to go back to relying on growing our power, and any effort to do so will decimate remaining natural sanctuaries just as it did 300 years ago.

    www.fern.org/fileadmin/uploads/fern/Documents/Up%20in%20Flames.pdf

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  42. John Oneill at 238:

    Sovacool is a peer reviewed scientific study.  You are attempting to substitute your personal opinion unsupported by any data or analysis at all.  This is a scientific site.  You must provide peer reviewed data to support your wild claims.  You are simply sloganeering.

    Uruguay produced 40% of its electricity from wind in 2020 while Sweden produced only 30% of its electricity from nuclear power.  If you claim Sweden as a nuclear success than Uruguay has to be a wind success. (Our world in data linked below).  Both have high hydro.

    Nuclear electricity generation is (2020 TWh, 2000 TWh) World 2,616, 2498, France 355, 414 Canada 95, 69 and Sweden 50, 57 TWh our world in data Generation of electricity from wind is (2020 TWh,2000 TWh) World 1590, 31, France 39,0.04, Canada 34, 0.16, Sweden 27, 0.46, US 336, 6, Uruguay 5.5, 0, Denmark 16, 4. IBID

    This data shows that worldwide nuclear is reducing or flat and everywhere is building out wind.  Solar is much the same.  Sweden and France are slowly shutting nuclear plants as renewable energy comes online.  That allows them to progressively reduce carbon emissions while switching to renewable energy.

    Talk to me about small modular reactors when they have a working pilot plant.  That will be in 2029 at the earliest.  Utilities are backing out of the NuScale project because of cost.  Safety questions remain.

    At 236 you said:

    "The BN600 and BN800 in Russia seem to be operating without any leaks or fires - unlike some of the new grid storage battery plants,"

    I provided proof of at least 14 fires at the BN600 plant.  Your claim of no fires was false.  I have to Google everything you say.  They have to build expensive, duplicate cooling systems so that they can repair the fire damage without shutting down the entire plant.  It is uneconomic to build duplicate cooling systems.  The World Nuclear Organization does not show any of these reactors under construction.  Please provide evidence to support your claim that two are under construction.

    Worldwide installation of renewable energy is increasing exponentially.  Your cherry picking a handful of countries that are not increasing wind or solar this year is simply an attempt to distract which will not work.  Any cursory look at data shows that installation of renewable energy is increasing rapidly while nuclear plants are not being started up.

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  43. Hey MA Rodger:

    Your link to Our World in Data is a great site.  I have been having trouble finding energy data updated to 2020 and they have everything!  It is easy to search.  Thanks for the link.

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  44. I case people missed it buried in the text from MA and michael, the web site Our World In Data has quite a bit more than just nuclear data. The main web site is:

    https://ourworldindata.org/

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  45. michael sweet at 242
    'Sovacool is a peer reviewed scientific study.'

    The paper you linked is behind a pay wall, but examples I have given show emissions from electricity generation, at least, are considerably lower in some nuclear-reliant countries than in comparable countries without it. For example, from 2000 to 2019, Germany's electricity generation from fossil fuels went down by 29%, France's ( to 2020) by only 1% ( from 'Our World in Data'). Nevertheless, in absolute terms, Germany was still getting 248 TWh from fossil fuels to France's 50 TWh. The difference in emissions would be even greater, since so much of Germany's power is from lignite, and even their 'renewable' thermal generation has a fairly hefty carbon footprint. The UK, which, unlike Germany, chose to close its coal plants instead of its nuclear ones, saw power from fossils fall by 49% over the same period. In 2020 the UK generated 5 TWh from coal, France 4 TWh, and Germany 134 TWh. (Denmark also made 4 TWh from coal, but it only has a twelfth the population of France or the UK.)

    https://ourworldindata.org/fossil-fuels

    My scepticism of Ben Sovacool's work stems from a paper he wrote, also peer reviewed, which claimed that nuclear power was responsible for three times as many bird deaths per watt hour delivered as wind turbines. This was based on a single incident of geese hitting cooling towers at a coal plant, and another isolated case of waterfowl dying in a copper mine waste pond. ( His estimates of lifecycle CO2 emissions from nuclear, in another paper, are rather higher than the IPCC's, but not as outrageous as some of the other authors he considers. )

    'Uruguay produced 40% of its electricity from wind in 2020 while Sweden produced only 30% of its electricity from nuclear power. If you claim Sweden as a nuclear success than Uruguay has to be a wind success.' I would say that Uruguay is a wind success, but the circumstances allowing that are limited. The world currently gets 86% of its energy from coal, oil and gas, and has done for the last forty years. Wind backed by hydro will not replace that - the gaps in wind power would simply be far greater than hydro could fill. I can't show you a grid running on SMRs yet, but likewise you can't show me one with significant battery storage.

    'I provided proof of at least 14 fires at the BN600 plant. Your claim of no fires was false.' I didn't claim they had not had any fires, I said they weren't having any currently. The last leak at the BN600 was in May 1994. https://www.gen-4.org/gif/upload/docs/application/pdf/2019-01/gifiv_webinar_pakhomov_19_dec_2018_final.pdf

    'The World Nuclear Organization does not show any of these reactors under construction. Please provide evidence to support your claim that two are under construction.'

    'The CFR-600 is a sodium-cooled pool-type fast-neutron nuclear reactor under construction in Xiapu County, Fujian province, China, on Changbiao Island...Construction of the reactor started in late 2017...A larger commercial-scale reactor, the CFR-1000, is also planned...On the same site, the building of a second 600 MW fast reactor CFR-600 was started in December 2020 and four 1000 MW CAP1000 are proposed.'

    https://en.wikipedia.org/wiki/CFR-600

    The Indian Prototype Fast Breeder Reactor, also sodium-cooled, is scheduled to go critical in October 2022 - though it's been delayed multiple times before. It's intended to close the fuel cycle from India's heavy water reactors, and allow the use of thorium, which India has very large reserves of.

    'Worldwide installation of renewable energy is increasing exponentially. Your cherry picking a handful of countries that are not increasing wind or solar this year is simply an attempt to distract which will not work. Any cursory look at data shows that installation of renewable energy is increasing rapidly while nuclear plants are not being started up.'

    Exponential growth is easy enough from a small base, but in the real world, it will eventually hit natural limits. In nearly every case, growth in solar has started falling, i.e. it's no longer exponential, when solar provides between five and ten percent of total generation. Wind has double the capacity factor, doesn't regularly drop to zero, and is usually less seasonal. Where there's plenty of hydro as backup, it does, in a few areas, help lower emissions to levels approaching those of a nuclear + hydro grid. In places like Texas or California, where it's backed by gas, average emissions stay higher. Since replacing current power fossil generators is only a small first step - we also need to provide clean power for much of the third world, and we've hardly started on industry and transport - it would be ill judged to rule out the world's second largest combustion-free energy source ( after hydro.) Nuclear can be installed as a plug-in replacement for coal plants, a role unsuited to power sources which spend much of the time powerless.

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    Moderator Response:

    [BL] Please make note of the fact that you are repeating claims and not addressing points made by others.

    I suggest that you re-read the Comments Policy, taking particular note of the sections on excessive repetition and sloganeering:

    • Comments should avoid excessive repetition. Discussions which circle back on themselves and involve endless repetition of points already discussed do not help clarify relevant points. They are merely tiresome to participants and a barrier to readers. If moderators believe you are being excessively repetitive, they will advise you as such, and any further repetition will be treated as being off topic.
    • No sloganeering.  Comments consisting of simple assertion of a myth already debunked by one of the main articles, and which contain no relevant counter argument or evidence from the peer reviewed literature constitutes trolling rather than genuine discussion. As such they will be deleted. If you think our debunking of one of those myths is in error, you are welcome to discuss that on the relevant thread, provided you give substantial reasons for believing the debunking is in error.  It is asked that you do not clutter up threads by responding to comments that consist just of slogans.
  46. John ONeill:

    Here is a free copy of the Sovacool paper apparently my previous link is broken.  It took me 15 seconds to find.  If you read the literature you would be able to do this yourself.  You are welcome to think anything you want.  The peer reviewed literature contradicts you.  You are sloganeering.

    At 236 you claimed:

    "If we really try to build out wind and solar there will be a substantial decrease in carbon emissions in a short period of time.' That's something I haven't seen, though I rather obsessively scan www.electricitymap.org/zone/JP-KY?wind=false&solar=false for examples of it." italiced is a quiote of me

    I provided Uruguay as an example of reduction of carbon emissions from renewable energy.  I found this clear example in less than 5 minutes on your reference.  This proves that you do not "obsessively scan" for examples.  You are simply trolling us.

    At 236 you claimed "The BN600 and BN800 in Russia seem to be operating without any leaks or fires"   I showed that the BN600 has had at least 14 fires.  You are trolling us again.

    At 238 you stated:

    "'These reactors cost even more to build than normal reactors. They will never be economic. No more are planned worldwide.' - Apart from the one Gates' company is developing, there's one being built in India, and one in China." Italics is you quoting me.  

    The reactors you cite in 245 are a completely different design and are new, experimental builds financed entirely by the government.  They are liquid sodium reactors, but are a different design.  As one design fails, nuclear supporters give it a new hat and claim it will finally work.  Your current claim that they are the same is false.  Construction of the Indian reactor begun in 2007 for completion in 2012.   Now due in 2022.  Every year they extend the operational date another year.  Typical nuclear build.

    More renewable energy was installed last year than all other power systems combined. 

    "IRENA’s annual Renewable Capacity Statistics 2021 shows that renewable energy’s share of all new generating capacity rose considerably for the second year in a row. More than 80 per cent of all new electricity capacity added last year was renewable, with solar and wind accounting for 91 per cent of new renewables." source

    At 245 you say:

    "Exponential growth [of renewable energy] is easy enough from a small base"

    In 2021 wind and solar power generated will surpass nuclear power worldwide.  Nuclear currently has a smaller base to ridicule than renewable energy, after 60 years of operation.  Nuclear generated less power in 2020 than in 2004.  They are not buiding enough nuclear power worldwide to replace retiring reactors.  You are trolling us again.

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    Moderator Response:

    [BL] Although countering repeated claims can be frustrating, please keep it civil.

  47. John ONeill:

    A free copy of the Sovacoll article concerning brds is here.  From the abstract:

    "The study estimates that wind farms and nuclear power stations are responsible each for between 0.3 and 0.4 fatalities per gigawatt-hour (GWh) of electricity while fossil-fueled power stations are responsible for about 5.2 fatalities per GWh. While this paper should be respected as a preliminary assessment ..."

    Your claim that Sovacool "claimed that nuclear power was responsible for three times as many bird deaths per watt hour delivered as wind turbines." is false.  Your description of Sovacool's work is so far from reality it is a waste of my time to address the facts.   Sovacool describes his study as preliminary.  He notes that all sources of energy are bad for birds.

    You present material that is completely false.  Keep in mind that your comments can be checked for accuracy.

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  48. Replying to micheal sweet 247

    If you or anyone else are interested, there's an extremely long thread here ( rivalling this one ) where Ben Sovacool responds to some rather trenchant criticism of his two papers on bird deaths, and then to further criticism of his response. Warning - Sovacool makes 36 entries in reply to an even larger number from various critics. 

    https://atomicinsights.com/sovacool-vs-lorenzini/

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    [BL] Link activated.

    The web software here does not automatically create links. You can do this when posting a comment by selecting the "insert" tab, selecting the text you want to use for the link, and clicking on the icon that looks like a chain link. Add the URL in the dialog box.

    It has been suggested that you re-read the comments policy. With regard to this current comment, please note the following section. If you feel that a link is relevant, do not just ask people to go and read it - provide some sort of indication of what you expect people to see. Your current comment is a bit light in that regard.

    No link or picture only. Any link or picture should be accompanied by text summarizing both the content of the link or picture, and showing how it is relevant to the topic of discussion. Failure to do both of these things will result in the comment being considered off topic.

  49. From 228, Michael Sweet

    'Freeze valves are apparently not used in any existing chemical or nuclear processes. Therefore the knowledge of their manufacture, use and failure modes is rudimentary. They are complicated and have many failure modes compared to normal mechanical valves. They open and close very slowly in emergencies. The size of pipes used is restricted. Test valves have suffered catastrophic failure.'

    Freeze valves are actually very simple - a short length of flattened pipe with fins on the outside, with a fan blowing air over it. Failure can hardly be 'catastrophic', because there's a very wide margin between the normal operating temperature of the molten salt, and that high enough to melt the metal holding it. If the metal is hot enough to melt, so is the salt in the freeze plug. If the reactor is not operating, there is no power going to the coolant fan. ( The Molten Salt Reactor Experiment, back in the 1970s, didn't make any power, so they used sensors and manual controls instead.) What's more, they are easy to test using non-radioactive versions of the salt, which are chemically identical but easier to handle. (Depleted uranium has very low radioactivity, and plutonium, usually a minor fraction of a thermal reactor's salt composition, can be substituted with cerium.) Failing open would shut the reactor down, which might be bad for the owner's financial return, but not really a safety concern.

    In fact, 'freeze valves' are widely used when working on power systems using water circuits, including nuclear ones - if a valve, pipe or pump needs maintenance, the pipe either side of it can be frozen and then cut, and the work done without having to drain the whole system. An MSR freeze valve is designed to drain the whole system, so there's very little to go wrong - they're 'fail safe'.

    In any case, valves of any sort are not a prerequisite for MSRs. One alternative is to have the salt level actively kept up by the main fuel pump. If the pump stops, the salt drains to a tank where fission cannot occur because of the geometry. Another is to surround the reactor with a salt with a higher melting point. If the reactor exceeds a predetermined temperature, fission will stop from fuel expansion and doppler broadening of the neutron absorption spectrum, and the surrounding salt will suck up the excess heat by change of state. Rupture disks are another option if there is any danger of overpressure.

    Finally, these guys - Copenhagen Atomics - are building and testing mechanical valves, among other components, and selling them to anyone else working in the field -2 minutes in to the video if you want to check my veracity in a hurry.

    https://www.youtube.com/watch?v=U7U7I7QkttM&ab_channel=gordonmcdowell

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    [BL] Link activated.

    The web software here does not automatically create links. You can do this when posting a comment by selecting the "insert" tab, selecting the text you want to use for the link, and clicking on the icon that looks like a chain link. Add the URL in the dialog box.

  50. John ONiel:

    A peer reviewed study, published in 2020, said:

    "Reliable mechanical valves that can withstand the corrosive and high-temperature conditions in Molten Salt Reactors (MSRs) have not yet been demonstrated. In their place, freeze valves (sometimes called freeze plugs) represent a unique nuclear design solution for isolating salt flow during operations." my emphasis.

    Your reply is "Freeze valves are actually very simple".   Apparently we do not need to verify that freeze valves work before we build these new nuclear designs.  I think most reasonable people would disagree.  Valves do not exist for MSR designs. 

    Watchng your Youtube advertisement, the company produces valves made out of stainless steel.  The paper linked above states clearly that no known materials can withstand the extreme conditions inside an MSR for the lifetime of a reactor.  Obviously, stainless steel would have been one of the first materials tested.  The valves you cite are only for short, experimental usage and are not exposed to the extreme hot, radioactive and corrosive environment for any significant amount of time.  These are not valves that can be actually used in a nuclear reactor.  They are valves used in test equipment to evaluate possible future valves once a supply of "unobtainium" is found.

    It is a waste of time to discuss speculative possible solutions to problems that are known to exist.  Obviously, you have no idea how possible valves can be built for MSR's since your reference is for a completely different use and you did not recognize that.  Suggesting that freeze valves are so simple that they do not need to be tested is absurd.  Freeze valves open and close too slowly to help in an emergency.  Engineers in the 1950's rejected their use. 

    Your suggestion that repairing pipes in a shut-down, cold, non-radioactive system is comparable to active regulation of a nuclear reactor core demonstrates that you do not care if the reactor you propose to build has been safely designed and tested.

    The entire discussion is premature since no proposed reactor design exists, only speculative rough proposals.  Come back to discuss MSR's when they have a buildable design.

    hat tip to Philippe Chantreau for producing the peer revidewed article about freeze valves.

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