Showing posts with label MSR. Show all posts
Showing posts with label MSR. Show all posts

Monday, October 21, 2019

Climate Solutions BS in Houston by AIChE

Subtitle: Still BS - Bad Science, No Solutions Needed

I attended a lunch presentation by Dr. Tom Rehm, 2019 Chair of STS-AIChE on October 18, 2019 on Climate Solutions, in LaPorte, Texas.   (STS is South Texas Section)

The main points are below in bold font, with my comments in parentheses.  These are based on my notes made at the time, and may not perfectly reflect what was said; any inaccuracies are due to what I believe I heard at the time. 

(Preface:  I believe that Tom Rehm is sincere in his beliefs about catastrophic, imminent global warming caused by CO2, however he has stated in public that even if it is not true, it is prudent to do something to prevent it.  (my paraphrase, probably not his exact words).  I suspect he is also sincere in his belief that nuclear power is the planet's saviour, and that all plastic production must end and rather soon.  It is disconcerting that the STS of AIChE has taken this approach, with those beliefs based on very bad science and not on the facts.  However, the chairmanship is for only one year, and Dr. Rehm will soon hand over the chair - January 1, 2010.  It seems, though, that the incoming Chair has similar views.   That is actually ok, though, since the solutions being advanced are not workable, will have outrageous impacts on all of society, require massive government support, and cannot be implemented in less than 5 decades anyway.  By then, the inevitable global cooling will be advanced and more than evident to everyone. -- End Preface) 

The main points:

UHI, urban heat island effect, is due to aerosols that cooled the air until approximately 1980, then cleaner air caused the cities to warm.  Clean air laws were enacted.  
(That is nice to see the effect of man-made aerosols mentioned, as that is one of the several causes of warmer temperatures that have nothing to do with increased CO2 in the atmosphere.  SLB has articles on the non-CO2 causes of warming, see link. )

Population decreased in a few urban areas but temperatures increased, therefore warming is not correlated to population growth. 
(This is an attempt to show that increased temperatures are not related to population growth, however I have asked Tom in the past how does he know the temperature increase in those few locations were not related to drought, El Nino, cleaner air, fewer clouds, more local humidity, and a host of other known causes of warming?   He made no answer then.)

USCRN, United States Climate Reference Network, has more than 100 pristine sites across the US, sites with no urban warming influence for the foreseeable future.   Mentioned Stovepipe Wells, CA (actually in Death Valley), and Alaska.    Showed a slight warming trend for these locations.  
(the misdirection here was to, again, make the point that warming occurs even where population is small.  As before, no mention of non-CO2 causes of warming, El Nino, droughts, etc.) 

Professor Monty Alger of Penn State called Tom to say he was fully behind the Climate Solutions initiative at AIChE.  Alger will be AIChE president for 2020. 
 (see  https://www.che.psu.edu/faculty/alger/ for a bio of Dr. Alger.  The incoming president of national AIChE is equally misguided on the bad science, BS, of man-made global warming.  However, as an academic, it is important for the national AIChE to support and assist the other academics who receive part of their grants and other funding from promoting man-made climate change.  It is obvious that more work for chemical engineers will occur in designing and building the various systems to capture CO2, remove some from the atmosphere.)

Tom said he was instrumental in getting AIChE to change their official stance on Global Warming with the 2019 statement on climate
(The previous statement on climate was essentially, "we don't take a position as the science is not settled," with the new, 2019 statement emphatically stating "Scientific analysis finds that non-natural climate change is occurring and has been strongly influenced by human-caused releases of greenhouse gases. . . . Adverse climate change poses threats to all of us, both individually and as a society. These threats fall squarely in the realm of the chemical engineer. . ."  It is certainly dismaying that so many in our society could be so badly fooled by the BS, the bad science.   What the current statement should say is "Some very bad scientific analysis finds that".... the causation should have mentioned the multiple known causes of warmer temperature, none of which are related to increased greenhouse gases.) 

Mentioned Hofmeister’s book “Why We Hate the Oil Companies.”  Former president, Shell Oil. 
(Not much to say here, having not read the book.  I suspect the theme is that oil companies have been hiding very bad facts for decades, have conspired to deceive the public and elected officials, the usual such things.   It is quite instructive that Shell is mentioned, as they are notorious for having lied to the Securities Exchange Commission about the extent of their oil reserves, and were fined for doing that.  Shell would do well in an era where oil is minimized in favor of natural gas consumption.  That appears to be a primary goal of those who espouse climate solutions. )

Said presenter Stephanie Thomas is a geologist.   Matthew Berg won best presentation award for SPTC in Sugar Land, 2019.
(I sat through both Thomas' and Berg's presentations at that conference.  Dr. Thomas is listed as having a PhD in Earth Sciences, not Geology.  Dr. Berg has a PhD in Hydrology.   I wrote on SLB on Dr. Thomas' presentation, see link.    I have not yet written an article on Dr. Berg's presentation, but it can be summarized as "flooding is getting worse, and global warming is the cause."  He claimed, with a straight face, that local temperatures are melting railroad rails.  Then, showed a slide of a distorted rail juncture.  I laughed at that one.)

Wants the world to be CO2-neutral by year 2030, and to do that we must make no more plastics.
(this one is quite incredible; I shook my head in disbelief.  The modern world depends far too much on plastics to stop production.  The disruption, increased costs, increased disease and illness, and increased energy consumption all are insurmountable factors that will make this one never happen.   For just a few examples, how will hospitals and medical practices function without plastic?  What will food packaging be made from, at what cost in product purity and increased discards, if not plastic?  What will sanitation piping be made from?  How will transportation vehicles maintain their current low weights (or mass) that allows excellent fuel economy?  This one is, to use the vernacular, a doozy.)

Renewables cannot do the job; 100 percent renewables is impossible.  Cited Austin, Texas as having grid stability problems at 20 percent renewables on the local grid.   Said that the local grid and amount of renewables is the critical issue.  
(on this minor point, we agree at least in part.  SLB has articles on the 100 Percent Renewables issue, I agree that the world will not likely ever be run entirely by renewables.   Where Rehm is wrong, though, is on the claim that 20 percent renewables causes instability on local grids.  The fact is that many locations in the US have much more than 20 percent renewable power that makes electricity.  The issue is not with the renewables, but with the flexibility of the other generating systems.  )

Mentioned the cost for renewables is prohibitively high, and the low capacity factor, 25 percent for solar and wind combined in Texas is a major obstacle
(this is a common talking point by the anti-renewables, pro-nuclear crowd.  The fact is, the renewable sources of wind and solar are very competitive in the areas where the wind is good and the solar energy is strong.  However, the economics of solar panels in high latitudes will continue to be very bad for many decades.  Solar does well, though, in sunny areas (not cloudy) in locations between 30 degrees north and south of the equator.  Wind is the most attractive generating source in many, many areas as thoroughly documented by the US Department of Energy and their annual Wind Technologies Market Reports.)

One solution is nuclear, with new designs as Professor Tsvetkov proposes.  Said nuclear has zero emissions,   New designs will not use water as the moderator.  
(Tsvetkov clarified that zero-emissions view in his earlier 2019 speech to AIChE, it is not true for the entire nuclear cycle.  see link to SLB article on Gen IV nuclear and Tsvetkov's presentation.  Gen IV nuclear plants are unproven, most have not been built, a few prototypes were abandoned as hopeless.  The increased safety and reduced costs claims are not true at all.  Nuclear is never the solution; it costs far too much and is far too dangerous. ) 

Favors a carbon tax as paramount importance
(A carbon tax, or tax on companies that produce CO2 in their operations, is favored by one segment and opposed by another.  Those in favor are typically oil and gas companies, the opposition are coal companies.  Burning coal produces much more CO2 per unit of energy released, typically 2 - 3 times as much as does burning natural gas.  So, a carbon tax is a perfect way to run coal companies out of business.  Is it any wonder that oil and gas companies favor that?  They get to sell more natural gas, usually as fuel to utilities.)  

Three steps to carbon neutrality: Mitigation, Adaptation, and Resiliency
The points on the slide for this statement included:
-Manufacturing Energy Efficiency - Mitigation
-Electricity Generation /Distribution  - Mitigation
-Transportation - Mitigation
-Urban Energy Efficiency - Mitigation
-Agricultural Practices - Mitigation
-Land Use Practices - Mitigation, Adaptation, Resiliency
-And, governmental policy solutions. 

(He did not discuss these points in detail, except for the next paragraph on Regenerative Agriculture.  My own experience over 40 years of engineering consulting and energy work as an employee in chemical manufacturing shows that none of the above are cost-effective, except for Transportation with electric battery-powered vehicles.  If one favors the Efficient Market Theory, radical changes must make any market more inefficient and thus more costly to operate.  The prospects of increased energy efficiency due to another world energy price shock, like the 1970s had, is virtually zero.  Oil is no longer subject to price increases, and in fact OPEC is in disarray and oil prices are decreasing.  There is a world-wide glut of natural gas, driving its prices down, and coal is on the decline except in a few isolated countries (India, China).  That leaves only a government-mandated carbon tax to force such decreased energy usage.  )

Favors Regenerative Agriculture – soil must increase carbon content to remove CO2 from the air. 
(with farming already a very slim profit endeavor, the costs to include carbon sequestration in soil must be subsidized to prevent bankruptcies.  This may be where the carbon tax comes in; a wealth transfer from CO2 producers to the farmers.  More on Regen Ag will be published shortly on SLB.  For now, it's just another scheme to transfer wealth and run the oil companies out of business.)

Electricity generation options he favors are nuclear and biomass.   Said nuclear has the best safety record of all types when calculated on fatalities per TWh/y produced.   
(I wonder if that includes the entire uranium mining and fuel preparation cycle, plant construction, generation, decommissioning, and spent fuel storage for centuries.  SLB has articles on the dubious safety record of nuclear power plants, see link to "Nuclear Radiation Injures People and Other Living Things,"  and link to "Near Misses on Meltdowns Occur Every 3 Weeks," and link to "US NRC Stops Study of Cancer Risks near Reactors."  As to biomass for power generation, there is too much power needed and not nearly enough biomass to burn.  These facts have been known for decades.  And, it gets worse.  No more biomass is produced each decade, but the power generation needed keeps increasing.)

(Next, Rehm really pushed nuclear, to end the talk) Nuclear is not presently used much due to unjustified public fear.    Said advanced nuclear plants are much safer 
("Unjustified fear" is a buzzword from nuclear proponents.  One must wonder how much fear was justified among the Russians, Europeans, and others when Chernobyl exploded and sent radiation around the planet?  How much fear was justified in Pennsylvania when Three Mile Island melted down and spewed radioactive steam into the skies?  Were the evacuated pregnant women supposed to remain calm, cool, and collected during those horrible few days?  How much fear was justified in Japan during and after the triple reactor meltdowns and explosions at Fukushima?   How much fear is justified among the entire population, now that nuclear plants are being built in third-world countries with earthquakes and other serious threats to the plants' integrity?   How much fear is justified now that cyber-security is a serious threat?  As to advanced nuclear plants being much safer, how could he possibly know?   None have been built except for a few tiny proof-of-concept plants.  SLB has articles on the safety of new nuclear designs, see link to "Thorium MSR No Better Than Uranium Process,"  and link to "High Temperature Gas Reactor Still A Dream" )

Advanced nuclear will recycle existing spent fuel and generate power from the recycled material, reducing toxic radioactive waste by a large amount. 
(Why bother?  Fuel is not the expensive part of running a nuclear plant.  Safety is not improved, either, as a previous article on SLB shows, see link to "Reprocessing Spent Fuel Is Not Safe."  )

Said SMR, small modular reactors, are the answer since they will be very low-cost to build in factories.  
(This is one of the same points made by Tsvetkov in his Gen IV speech to AIChE, and the same rebuttal applies: any cost reduction due to volume production requires millions of units, not hundreds as SMR would have.  Economy of scale overwhelms any production cost reductions.  NB, the wind energy business for WTG (wind turbine generators) has the same issue for blade manufacturing.  The US industry builds and installs approximately 8 GW per year, at an average of 2.4 MW per WTG, thus the average number of WTG installed was 3,333.  Number of blades made was 10,000 for 2018.  Even that 10,000 items does not give low cost, so the industry strives for cost reductions via economy of scale with ever-larger WTG per unit.  Offshore, size went from 2 to 4 to 8 and now 12 MW.   Onshore, size from 1 to 3 and now 5 MW per WTG.  See link to SLB article on SMR and all the many drawbacks, "No Benefits From Smaller Modular Nuclear Plants." )

End of speech.  

In the Q&A portion, I asked this Question:  how much will electricity prices increase if the proposed solutions are implemented?  He admitted it will be a big increase but did not give a number. 

The transition period will require decades, Shell says 50 years, he stated BP and ExxonMobil have similar time frames.  
(how does this square with the earlier statement of carbon-neutral by 2030?  That’s only 11 years away)

Q:  how will SMR reduce costs, when economy of scale is the major factor in nuclear plant costs?  He had no answer for that, either.  

Q:  On USCRN slides that showed a warming, how much of the measured warming was due to CO2 increase, and how much to other factors like cleaner air – he mentioned pollution laws cleaned the air around 1980 and temperatures immediately increased in those locations.   His response was to show a graph purporting to show IR gap in Earth’s radiated energy out to space, with CO2 responsible for the gap.   My rebuttal was, the gap is also exactly where water vapor H2O absorbs, so how do they know it is due to 300 – 400 ppm of CO2, and not due to several percent of water vapor? 

Conclusion

The points made in this speech are typical of the misinformation and Bad Science (BS) of many in the climate alarmism camp.   So much of what they know, just isn't so. (a quote from Ronald Reagan).   The good news is, almost none of this is ever going to happen.  Plastics are here to stay.  Nuclear plants are a dying breed, and the sober review process and high standards at the NRC will prohibit the approval of the Gen IV reactors.   Economics alone will kill off any other reactor designs, such as the NuScale small modular reactor system that is presently undergoing safety review at the NRC.  Low-price wind electricity and natural gas power have doomed nuclear power, which is a very good thing.   Wind energy is a booming business, and is here to stay.  Solar is also booming in those areas of the world, as stated above, not far from the Equator where the sunshine is strong.   The AIChE will likely see the Climate Solutions division, or initiative, whatever it is called, wither away in just a few short years.  

This website will have articles and updates on that, as they occur. 


Roger E. Sowell
Houston, Texas
copyright (c) 2019 by Roger Sowell - all rights reserved




Topics and general links:

Nuclear Power Plants.......here
Climate Change................herehere,  and here
Fresh Water......................here
Engineering......................here  and here
Free Speech.................... here
Renewable Energy...........here  


Thursday, April 11, 2019

On Generation IV Nuclear Plants

Subtitle: Safer and Cheaper, or Just Make-Work Projects?

Tonight, 4-11-2019, the South Texas Section of AIChE will have the monthly dinner meeting, at which the presentation will discuss the research and status of Generation IV nuclear power plants.  This topic is the result, most likely, of the mis-guided belief by the current Section leadership that man-made climate change requires non-carbon-based electric power generation.  Therefore, they say, more nuclear plants should be built.  And, since no one can deny that the existing crop of nuclear power plants are far too dangerous and far too costly, they see a need for a new generation of nuclear designs.   This article poses a few questions I would ask, given the opportunity, about these planet-saving Gen IV nuclear power plants. 

What is a Gen IV plant?  These are, according to the NRC, nuclear plant designs that do not use light water as a moderator in the reactor.  At present, the existing plants use boiling water, or high pressure water in the reactor core as neutron moderators.  These have been shown to be far too expensive, as stated above.   The Gen IV plants will use various other things, such as graphite spheres in a high-temperature gas reactor (HTGR), molten fluoride salt in the reactor (MSR), or various molten or liquid metals in the reactor (molten lead, molten sodium, e.g.) .  

The questions, for now, include these:  What is the safety for Gen IV?  Will these plants require subsidies?  What is the on-line  capacity factor, or reliability of Gen IV?  What is the cost to construct?  What is the cost to operate?  What is the cost to decommission?  What are the issues with long-term spent fuel?

Safety

Will Gen IV reactors be safe, so safe that there is no longer an absolute need for the US government to provide damage payments for a catastrophic nuclear incident?  At present, every reactor enjoys such protection under the Price-Anderson Act.  Insurance companies refuse to insure nuclear plants, above a modest amount that is required by federal law.   Will these plants have materials of construction that operate reliably and safely for decade after decade?  We note that molten fluoride salts had serious metal cracking and embrittlement in earlier tests, are there proven alloys today that provide a safe operating system?

Subsidies

Will Gen IV plants require the numerous subsidies that current generation of light water reactors have?  SLB has articles on the numerous subsidies, such as liability for radiation leaks via the Price-Anderson Act, construction loan guarantees, new reactor direct subsidies for the first 10 years of operation, making lawsuits during construction almost impossible, and others.

Capacity Factor

Will Gen IV reactors run at 90 percent output year after year, for 40 years or more?  Will these exotic materials, molten lead, molten sodium, molten fluoride salts, create operating problems that shut the plant down routinely?  Test reactors over the years have had very serious drawbacks with pumping such materials, to name just one. 

Cost to Construct  

Will Gen IV plants be built at a low cost, so they can actually compete in the electricity market?  We see that pressurized water reactors now have an outrageous cost, of $12 billion for a 1000 MWe output.   How can anyone know what the costs to build will be?  The industry has time after time given low-ball initial costs, then see the actual costs balloon to 3, 4, and 5 times that initial cost.   

Cost to Operate

Will Gen IV plants have a low cost to operate, so that they can actually compete in the market?  We see today that plant after plant in the US cannot compete, even on their cash costs.  Current plants are shutting down, or crying to the government for more and more subsidies to keep the plants operating.   

Cost to Decommission

Will Gen IV plants require billions of dollars, and decades of time to decommission when the plants finally close?  Who provides that money?  Will it be a government subsidy, like the light water reactors now enjoy?

 Long-term Issues with Spent Fuel

Will the Gen IV reactors have spent fuel that must be stored, guarded, and cooled for centuries?  What are those radioactive byproducts, and what are the toxicity issues?  What requirements will be made to ensure many generations are safe from deadly radiation from these plants?

These questions will suffice, for now.   I hope to ask a question or two.

UPDATE:  The meeting concluded, my thoughts and comments are on the next post at this link.  end update 4-12-2019


Roger E. Sowell, Esq.
Houston, Texas
copyright (c) 2019 by Roger Sowell - all rights reserved



Topics and general links:


Nuclear Power Plants.......here
Climate Change................here  and here
Fresh Water......................here
Engineering......................here  and here
Free Speech.................... here
Renewable Energy...........here  

Saturday, June 6, 2015

More Thorium Silliness

Just a few thoughts that came to mind while reading comments on WUWT, the latest puff-piece on Thorium-based nuclear power plants. 

First, very few commenters have a grasp of what a molten salt is or does, especially when that molten salt contains radioactive thorium and uranium and other fission products.  

One comment, in particular, shows a vast ignorance of economics. claiming ". . . near-free (sic) and unlimited electrical power ($0.03/kWh), which will gut the remaining industrial sectors of Western economies. . ."  This refers to thorium-powered nuclear plants built in China.   The 3 cents per kWh might be the fuel and variable operating cost, but certainly does not include amortized capital costs.  As shown previously on SLB, a molten-salt reactor using liquid fluoride salts will cost much more than the present generation of uranium-powered pressurized-water reactors, and those cost approximately $10,000 per MW or more.  The per-kWh cost just for the capital cost would be approximately 25 cents, depending on how much state subsidy is applied to the capital cost.    Note: apparently "forgetting" to include the capital costs is a favorite ploy of nuclear proponents, because it allows them to compare (barely favorably) a nuclear plant's "cost" to natural gas.  

Another clueless commenter states ". . . there isn’t really much for the CHinese (sic) to do except size up the design. . . "  This particular commenter claims to be ". . .a design engineer who worked on projects for nearly 40 years. . ."   The "size up the design" refers to scale-up of a thorium molten salt reactor.   As I wrote elsewhere on SLB, scale-up from the pilot plant size at Oak Ridge to a full-scale commercial plant of 1,000 MW electrical output is a massive, daunting task.  (see link)  In pertinent part: "Scale-up from ORNL size (7 MW thermal) by 500 times is an enormous challenge.   Note that scale-up with a factor of 7 to 1 is a stretch, yet such a factor (using 6) requires four steps (40, 250, 1500, and 3500) to use round numbers.   Each larger plant requires years to design, construct, and test before moving to the next size, and that is if the larger design actually works the first time."  

The same clueless commenter on scale-up added to his list of errors with this:  ". . .corrosion problems that some rag on about . . . were all but solved. . ."   This refers to the very real corrosion and cracking in the reactor material, in fact, any material that touched the hot molten radioactive fluoride salt.  A material was developed and tested, but not for the 40 or more years with multiple heating-up and cool-down cycles that a commercial reactor must withstand, not to mention any vibrational stresses caused by any earthquakes.   The Oak Ridge National Laboratory "developed (in 1977) an improved and very expensive alloy Hastelloy N for nuclear applications with molten Fluoride salts.   In tests, Hastelloy N with Niobium (Nb) had much better corrosion resistance to molten fluoride salts."  (source: link just above from SLB article on thorium molten salt reactors).  

There are many other, equally silly comments. 

Roger E. Sowell, Esq. 

Marina del Rey, California
copyright (C) 2015 by Roger Sowell




Wednesday, August 27, 2014

Molten Salt Reactor Not Good To Go

Subtitle: Extolling Virtues and Ignoring Faults is Deceptive 

A laughable post appeared today at WattsUpWithThat, titled "A Universally Acceptable and Economical Energy Source?"    The article describes, in over-the-top glowing terms, a molten salt nuclear reactor to produce commercial power.    Apparently the author, and those who commented on the post, have not read my article 28 on TANP from July 20, 2014 in which the multiple drawbacks of a MSR (molten salt reactor) are provided.   Nothing has changed since July, however, nuclear cheerleaders continue to sell, sell, sell the gullible, the ill-informed, their desperate message of Nuclear Is Cheap!  Nuclear Is Safe!    Nothing could be farther from the truth.     Link here to my earlier article on MSR. 

To recap the many drawbacks:

MSR will have much more expensive materials of construction for the reactor, steam generator, molten salt pumps, and associated piping and valves, compared to the PWR design.   There will be no cost savings, but likely a cost increase.  That alone puts MSR out of the running for future power production.  

The safety issue is also not resolved, as pressurized water leaking from the steam generator into the hot, radioactive molten salt will explosively turn to steam and cause incredible damage.  The chances are great that the radioactive molten salt would be explosively discharged out of the reactor system and create more than havoc.  Finally, controlling the reaction and power output, finding materials that last safely for 3 or 4 decades, and consuming vast quantities of cooling water are all serious problems.  

The greatest problem, though, is likely the scale-up by a factor of 250 to 1, from the tiny project at ORNL to a full-scale commercial plant with 1500 MWth output.   Perhaps these technical problems can be overcome, but why would anyone bother to try, knowing in advance that the MSR plant will be uneconomic due to huge construction costs and operating costs, plus will explode and rain radioactive molten salt when (not if) the steam generator tubes leak.    There are serious reasons the US has not pursued development of the thorium MSR process. 


The WUWT article actually states some laugh-out-loud aspects of the "new" design.  First, the "new" design supposedly uses zero cooling water.   At the same time, the author claims higher efficiency.  Any decent process engineer will tell the author that waste heat must be dissipated to some heat sink, either cooling water or ambient air.  Cooling water is the usual choice because it is usually colder than air but more importantly, the capital cost of a water-cooled heat exchanger is far less than a comparable air-cooled heat exchanger.   A water-cooled exchanger is also far more compact, has fewer operating problems, and is not subject to serious control issues that air-cooled exchangers have.  

Next, the author claims the near-zero, or low pressure, for the molten salt as a safety feature.  As shown above, and in the TANP article 28, materials leak when tubes corrode, and the leak is from high-pressure into the low-pressure molten salt. 

Finally, the author claims a 500 MWe plant will cost only $2 billion and require only 36 months to construct.   That is approximately 1,500 MWth output.  That is indeed laughable, to have such a very low cost.  But then, nuclear advocates are very prone to hawking low-balled construction cost estimates, then blaming anyone but themselves for cost over-runs.  We see this time and again.   

The final point, and one that shall always be the deal-killer:  if the MSR reactor system was any good at all, why has it not already been developed, designed, tested, constructed, operated at larger and larger scales, and completely dominated the commercial power industry?   The answer is, of course, that MSR has insurmountable engineering issues, which are well-known to those in the industry.  

A version of the MSR is being built, we are told, in China.  Perhaps economics does not matter to them.  Perhaps operating problems also do not matter to them.  Perhaps the state-run media will refuse to report on the plant explosions and other serious upsets that will inevitably occur.  

Roger E. Sowell, Esq.
Marina del Rey, California

Copyright (c) 2014 by Roger Sowell  -- All rights reserved  

Sunday, July 20, 2014

The Truth About Nuclear Power - Part 28

Subtitle: Thorium MSR No Better Than Uranium Process

Preface   

This article, number 28 in the series, discusses nuclear power via a thorium molten-salt reactor (MSR) process.   (Note, this is also sometimes referred to as LFTR, for Liquid Fluoride Thorium Reactor)   The thorium MSR is frequently trotted out by nuclear power advocates, whenever the numerous drawbacks to uranium fission reactors are mentioned.   To this point in the TANP series, uranium fission, via PWR or BWR, has been the focus.  Some critics of TANP have already stated that thorium solves all of those problems and
Thorium Molten Salt Reator process
source:  Idaho National Lab
therefore should be vigorously pursued.  Some of the critics have stated that Sowell obviously has never heard of thorium reactors.   Quite the contrary, I am familiar with the process and have serious reservations about the numerous problems with thorium MSR.  


It is interesting, though, that nuclear advocates must bring up the MSR process.  If the uranium fission process was any good at all, there would be no need for research and development of any other type of process, such as MSR and fusion.   Indeed, as already pointed out in TANP, uranium fission plants have barely captured 11 percent of world-wide electricity production after 50 years of heroic efforts.   One would expect, if nuclear power were as great as the advocates claim, that nuclear plants would already supply 80 or 90 percent of all electric power in the world.  Clearly, they do not because they are not at all great, they have enormous and insurmountable drawbacks in cost, safety, and toxic product legacy left for future generations.    Once the thorium MSR process is discussed in this article, the next article will discuss yet a third hope for the nuclear advocates, in case fusion fizzles out and MSR melts away to nothingness.   That next article will be on high-temperature gas reactors, the HTGR.   As will be seen, HTGR also has serious drawbacks.  

One final preliminary point: some of the nuclear advocates that push MSR lament the fact that, many years ago, thorium MSR lost in a competition with uranium PWR to provide propulsion for ships and submarines for the US Navy.   They say, wrongly, that Admiral Rickover chose uranium PWR over thorium MSR so that the US could develop atomic bombs.  What is much more likely the reason uranium PWR won is that the materials used for the MSR developed the severe cracking described below.   No Admiral in charge of submarines could take a chance on the reactor splitting apart from the shock of depth charges.    

The Idaho National Lab MSR Description  (see drawing above)

"The Molten Salt Reactor (MSR) system produces fission power in a circulating molten salt fuel mixture with an epithermal-spectrum reactor and a full actinide recycle fuel cycle. In the MSR system, the fuel is a circulating liquid mixture of sodium, zirconium, and uranium fluorides. The molten salt fuel flows through graphite core channels, producing an epithermal spectrum. The heat generated in the molten salt is transferred to a secondary coolant system through an intermediate heat exchanger, and then through a tertiary heat exchanger to the power conversion system. The reference plant has a power level of 1,000 MWe. The system has a coolant outlet temperature of 700 degrees Celsius, possibly ranging up to 800 degrees Celsius, affording improved thermal efficiency. The closed fuel cycle can be tailored for the efficient burnup of plutonium and minor actinides."  - See link 


Thorium’s Listed Advantages 

a) Fuel is plentiful because thorium is abundant

b) Fuel is cheap on a kWh produced basis

c) Molten salt reactor supposedly is safer, via a solid salt plug underneath the reactor that melts upon overheating if power is lost or some other upset occurs.   This allows the reactor contents, hot molten fluoride salts with radioactive thorium, uranium, and plutonium, to flow by gravity into several separate collection chambers to self-cool.

d) Low pressure reactor using molten salt – supposedly safer than a high-pressure PWR design. 

Oak Ridge  MSR Test Project

a) The reactor was small, with thermal output only 7 MWth.  The reactor process had no steam generator and no electricity was produced.  It ran only a few months.

b) Metal that was used for contacting molten salt developed intergranular cracking; completely unsuitable for commercial reactor use.  see link

c) ORNL then developed (in 1977) an improved and very expensive alloy Hastelloy N for nuclear applications with molten Fluoride salts.   In tests, Hastelloy N with Niobium (Nb) had much better corrosion resistance to molten fluoride salts.  

Future MSR designs and problems

a) The MSR design is much like a PWR design: each has a reactor, steam generator, and turbine/generator for the three primary sections.  However, as shown in the Idaho National Lab drawing above (INL), there are four loops in this design.  PWR has three circulating fluid loops: cooling water, boiler feedwater/steam, and the primary heating loop,  Yet, the MRS has a fourth loop, for radioactive molten salt for MSR.    Any MSR design that hopes to be economic will also be huge, likely in the 1000 MWe output size, to employ economy of scale.  This requires scaleup of approximately 500-to-1 compared to the ORNL project.   With a cycle efficiency of approximately 30 to 33 percent, the thermal output will be approximately 3500 MWth.   Scaleup from ORNL size by 500 times is an enormous challenge.   Note that scaleup with a factor of 7 to 1 is a stretch, yet such a factor (using 6) requires four steps (40, 250, 1500, and 3500) to use round numbers.   Each larger plant requires years to design, construct, and test before moving to the next size, and that is if the larger design actually works the first time.    It is also instructive (and very, very expensive) that the MSR design has a dual-compressor and heat removal fluid instead of the conventional steam condenser system.  Costs and operating problems for this design are much, much greater than for a PWR.  

b) The materials of construction for a very hot molten Fluoride salt mixture will likely be extremely expensive, if made of Hastelloy N to prevent the widespread cracking found at ORNL.   It remains to be seen if even Hastelloy N will have a sufficient strength and thickness after 40 years of service. 

c) Pumping the very hot, corrosive, molten salt mixture will require expensive alloy materials, and due to the salt’s density, high horsepower for pumping.   Also, pumping a hot molten radioactive salt requires sophisticated pump seals to ensure safety and prevent leaks.   As described above, the thorium MSR design will have four main circulating loops, while a PWR system has only three.   However, the cost for MSR hot molten salt circulation pump will be more expensive than the PWR pressurized water circulation pump due to the high-cost alloy required, and the almost double horsepower motor to drive the pump. 

d) If a molten salt pump is not used, circulation can be achieved by a thermal density difference loop.  However, this also presents serious design and control problems.  

e) The steam generator design presents a complex and likely insurmountable problem. Even if a successful design is somehow created, leaks of high-pressure water into the low-pressure molten salt are inevitable and will create all manner of hell. Havoc is too mild for the mess that will happen.   Water that contacts the hot molten salt will explode into steam, possibly rupturing the piping or equipment and flinging radioactive molten salt in all directions.   In addition, the steam generator’s material of construction also must resist the hot, corrosive molten salt.  The steam generator will also likely be made of Hastelloy N, which adds to the already high cost of the plant.   It is also notable that the INL MSR design has two heat exchangers for the steam generator loop, which decreases overall cycle thermal efficiency.   It does not increase safety, as water will leak into the molten salt. 

f) Controlling the plant output, adding more fuel, and removing unwanted reaction byproducts, all are obstacles.  

g) With the low thermal efficiency, MSR plants will require approximately the same quantity of cooling water as uranium fission plants.   That, as discussed previously in TANP, is a serious disadvantage in areas that are already short of water. 

Conclusion

It can be seen then, that thorium MSR has few advantages, if any, over PWR.  They each have three or four circulating loops and pumps, however MSR will have much more expensive materials for the reactor, steam generator, molten salt pumps, and associated piping and valves.   There will be no cost savings, but likely a cost increase.  That alone puts MSR out of the running for future power production.  

The safety issue is also not resolved, as stated above: pressurized water leaking from the steam generator into the hot, radioactive molten salt will explosively turn to steam and cause incredible damage.  The chances are great that the radioactive molten salt would be discharged out of the reactor system and create more than havoc.  Finally, controlling the reaction and power output, finding materials that last safely for 3 or 4 decades, and consuming vast quantities of cooling water are all serious problems.  

The greatest problem, though, is likely the scale-up by a factor of 500 to 1, from the tiny project at ORNL to a full-scale commercial plant with 3500 MWth output.   Perhaps these technical problems can be overcome, but why would anyone bother to try, knowing in advance that the MSR plant will be uneconomic due to huge construction costs and operating costs, plus will explode and rain radioactive molten salt when (not if) the steam generator tubes leak.    There are serious reasons the US has not pursued development of the thorium MSR process.  Reports are, though, that China has started a development program for thorium MSR, using technical information and assistance from ORNL.   One hopes that stout umbrellas can be issued to the Chinese population that will withstand the raining down of molten, radioactive fluoride salt when one of the reactors explodes.  

Previous Articles

The Truth About Nuclear Power emphasizes the economic and safety aspects by showing that (one) modern nuclear power plants are uneconomic to operate compared to natural gas and wind energy, (two) they produce preposterous pricing if they are the sole power source for a grid, (three) they cost far too much to construct, (four) use far more water for cooling, 4 times as much, than better alternatives, (five) nuclear fuel makes them difficult to shut down and requires very costly safeguards, (six) they are built to huge scale of 1,000 to 1,600 MWe or greater to attempt to reduce costs via economy of scale, (seven) an all-nuclear grid will lose customers to self-generation, (eight) smaller and modular nuclear plants have no benefits due to reverse economy of scale, (nine) large-scale plants have very long construction schedules even without lawsuits that delay construction, (ten) nuclear plants do not reach 50 or 60 years life because they require costly upgrades after 20 to 30 years that do not always perform as designed, (eleven) France has 85 percent of its electricity produced via nuclear power but it is subsidized, is still almost twice as expensive as prices in the US, and is only viable due to exporting power at night rather than throttling back the plants during low demand, (twelve) nuclear plants cannot provide cheap power on small islands, (thirteen) US nuclear plants are heavily subsidized but still cannot compete, (fourteen), projects are cancelled due to unfavorable economics, reactor vendors are desperate for sales, nuclear advocates tout low operating costs and ignore capital costs, nuclear utilities never ask for a rate decrease when building a new nuclear plant, and high nuclear costs are buried in a large customer base, (fifteen) safety regulations are routinely relaxed to allow the plants to continue operating without spending the funds to bring them into compliance, (sixteen) many, many near-misses occur each year in nuclear power, approximately one every 3 weeks, (seventeen) safety issues with short term, and long-term, storage of spent fuel, (eighteen)  safety hazards of spent fuel reprocessing, (nineteen) health effects on people and other living things, (twenty) nuclear disaster at Chernobyl, (twenty-one) nuclear meltdown at Three Mile Island, (twenty-two)  nuclear meltdowns at Fukushima, (twenty-three) near-disaster at San Onofre, (twenty-four) the looming disaster at St. Lucie, (twenty-five)  the inherently unsafe characteristics of nuclear power plants required government shielding from liability, or subsidy, for the costs of a nuclear accident via the Price-Anderson Act, and (twenty-six) the serious public impacts of large-scale population evacuation and relocation after a major incident, or "extraordinary nuclear occurrence" in the language used by the Price-Anderson Act.  Additional articles will include (twenty-seven) the future of nuclear fusion, (twenty-eight) future of thorium reactors, (twenty-nine) future of high-temperature gas nuclear reactors, and (thirty), a concluding chapter with a world-wide economic analysis of nuclear reactors and why countries build them.  Links to each article in TANP series are included at the end of this article.



Additional articles will be linked as they are published. 













Part Twenty Three - San Onofre Shutdown Saga
Part Twenty Four - St Lucie Ominous Tube Wear
Part Twenty Seven - Power From Nuclear Fusion
Part Twenty Eight - this article 


Part Twenty Nine - High Temperature Gas Reactor Still A Dream

Part Thirty - Conclusion

Roger E. Sowell, Esq. 
Marina del Rey, California