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
Wednesday, August 27, 2014
Thursday, August 21, 2014
Time-Shifting Building Cooling
Subtitle: How To Cut Power Bills and Still Cool The Building
It has long been known that one can save on the power bill by using cheap power at night to chill water, or freeze the water into ice, then using the cold created thereby the next day to provide air conditioning. University of Southern California, USC, has done this for some years. Today, an article is published showing how Goldman Sachs is doing the same for its large skyscraper in Wall Street. see link
The beauty of the system is it can also be a way to cut power prices even more - especially when very expensive power prices exist due to brand-new nuclear power plants. Instead of using electricity at night, one would purchase natural gas to run thermal chillers, store the chilled water or ice, then run only low-powered fans and pumps to chill the building the next day. Customers in Georgia and South Carolina will soon be looking into this with great interest as the very, very expensive new nuclear plants are built on their grids.
Removing a large load from the grid - especially at night - forces nuclear plants to reduce rate at night. The utility then must request a rate increase to pay for the nuclear plant, since fewer kWh are produced. This makes it even more attractive for its customers to either stop buying power, generate their own power, or as this article shows, purchase cheap natural gas at night in order to not run expensive air conditioners the next day.
As shown earlier in The Truth About Nuclear Power, part 7, as nuclear power percentage increases on a grid, more and more customers will opt out of the grid by reducing their purchases, self-generating, or by other means. see link
Roger E. Sowell, Esq.
Marina del Rey, California
Copyright (c) 2014 by Roger Sowell -- All rights reserved
It has long been known that one can save on the power bill by using cheap power at night to chill water, or freeze the water into ice, then using the cold created thereby the next day to provide air conditioning. University of Southern California, USC, has done this for some years. Today, an article is published showing how Goldman Sachs is doing the same for its large skyscraper in Wall Street. see link
The beauty of the system is it can also be a way to cut power prices even more - especially when very expensive power prices exist due to brand-new nuclear power plants. Instead of using electricity at night, one would purchase natural gas to run thermal chillers, store the chilled water or ice, then run only low-powered fans and pumps to chill the building the next day. Customers in Georgia and South Carolina will soon be looking into this with great interest as the very, very expensive new nuclear plants are built on their grids.
Removing a large load from the grid - especially at night - forces nuclear plants to reduce rate at night. The utility then must request a rate increase to pay for the nuclear plant, since fewer kWh are produced. This makes it even more attractive for its customers to either stop buying power, generate their own power, or as this article shows, purchase cheap natural gas at night in order to not run expensive air conditioners the next day.
As shown earlier in The Truth About Nuclear Power, part 7, as nuclear power percentage increases on a grid, more and more customers will opt out of the grid by reducing their purchases, self-generating, or by other means. see link
Roger E. Sowell, Esq.
Marina del Rey, California
Copyright (c) 2014 by Roger Sowell -- All rights reserved
Monday, August 18, 2014
French Nuclear Reactors Too Old - Cannot Cut It
An excellent article from EurActive,com, dated 8/18/2014, showing the weakness of aging nuclear power plants not just in France, but other countries in Europe. As the nuclear plants grow older, their time off-line for maintenance and inspection increases. see link
Yet another reason nuclear plants do not last 60 years, as some advocates claim. Still another reason nuclear plants have higher costs per kWh produced: their output falls off as they age, and capital costs and fixed operating costs must be spread out over fewer and fewer kWh sold. From the article:
" EDF's average load factor for its French nuclear fleet [was] 73 percent in 2013, which is also down from its highest level of 77.6 percent in 2005, the company's 2013 results show." (load factor is the ratio of the actual output to the nameplate capacity)
The nuclear plants also become less and less reliable as they age, requiring 100 percent backup ready and running to take over the load when the plants are shut down. Sound familiar? This is the constant whining from the nuclear advocates about "unreliable" wind and solar power. Yet, with a nuclear plant, the grid experiences approximately 1000 MW of power loss instantly when the nuke stops.
At the present, 50 percent of the nuclear plants in Belgium are off-line for maintenance. The power must be provided from other plants - essentially 100 percent backup for those plants.
The Truth About Nuclear Power series (30 articles in total) address many of the same issues in Part 10, 11, 15, and 16 (see links below)
Yet another reason nuclear plants do not last 60 years, as some advocates claim. Still another reason nuclear plants have higher costs per kWh produced: their output falls off as they age, and capital costs and fixed operating costs must be spread out over fewer and fewer kWh sold. From the article:
" EDF's average load factor for its French nuclear fleet [was] 73 percent in 2013, which is also down from its highest level of 77.6 percent in 2005, the company's 2013 results show." (load factor is the ratio of the actual output to the nameplate capacity)
The nuclear plants also become less and less reliable as they age, requiring 100 percent backup ready and running to take over the load when the plants are shut down. Sound familiar? This is the constant whining from the nuclear advocates about "unreliable" wind and solar power. Yet, with a nuclear plant, the grid experiences approximately 1000 MW of power loss instantly when the nuke stops.
At the present, 50 percent of the nuclear plants in Belgium are off-line for maintenance. The power must be provided from other plants - essentially 100 percent backup for those plants.
The Truth About Nuclear Power series (30 articles in total) address many of the same issues in Part 10, 11, 15, and 16 (see links below)
Part Eleven - Following France in Nuclear Is Not The Way To Go
Part Fifteen - Nuclear Safety Compromised by Bending the Rules
Part Sixteen - Near Misses on Meltdowns Occur Every 3 Weeks
Part Sixteen - Near Misses on Meltdowns Occur Every 3 Weeks
Roger E. Sowell, Esq.
Marina del Rey, California
Copyright (c) 2014 by Roger Sowell. All rights reserved.
Saturday, August 16, 2014
Speech on Fertilizer Explosion in West - Texas 2013
I am happy to accept a speaking engagement for the Southern California section of AIChE, (American Institute of Chemical Engineers) for their September, 2014 monthly meeting. My topic will be the safety issues that led to the fatal explosion in West, Texas, of an ammonia-based fertilizer distribution company, and the legal issues that ensued.
The little town is a bit south of Dallas. The event started with a fire, followed a few minutes later by a tremendous explosion. Several people lost their lives in the explosion. A number of structures were destroyed or damaged. The explosion registered on earthquake seismometers as 2.1 intensity.
More on the speech will be added after the meeting.
Roger E. Sowell, Esq.
Marina del Rey, California
(c) Copyright 2014 by Roger Sowell All rights reserved.
The little town is a bit south of Dallas. The event started with a fire, followed a few minutes later by a tremendous explosion. Several people lost their lives in the explosion. A number of structures were destroyed or damaged. The explosion registered on earthquake seismometers as 2.1 intensity.
More on the speech will be added after the meeting.
Roger E. Sowell, Esq.
Marina del Rey, California
(c) Copyright 2014 by Roger Sowell All rights reserved.
Sunday, August 3, 2014
The Truth About Wind Energy - Part One
Subtitle: Wind Energy for Long Term Power
Following the success of a 30-article series on The Truth About Nuclear Power see link, this article begins a similar series on Truth About Wind Energy, TAWE. Arguments rage about wind power, with detractors making wild claims about high electric power costs, grid instabilities, unfair subsidies from government, death to flying birds and mammals, unsightly turbines blighting views, and others. Supporters show that wind has enormous potential to replace almost every other form of grid power, that grids operate stably and will be even better in the future, subsidies are found in other forms of power generation - especially nuclear power, there is an urgency to develop renewable power and global warming has nothing to do with it, and many other points that favor wind power.
This series of articles, planned to be approximately one dozen, takes the many arguments and looks at each one factually, with sound engineering, economics, legal aspects, and policy objectives.
This first article is a work in-progress, and will likely be modified from time to time. As with TANP articles, each article in the series will be linked at the bottom as it is published.
A first effort at topics for TAWE include: Is wind economic? Costs to install wind turbines? Annual output, capacity factor? What about subsidies? Technology types for turbines? Onshore vs Offshore potential? Impact on existing grids? Backup power supplies required? Experience shows us what? Emissions from backup plants? Impact on birds, bats? Safety – is anyone injured? Brief history of wind power? Longterm outlook for energy supplies? Time-shifting energy via storage and discharge? A concluding chapter.
Update: 8/4/2014 - Is wind economic?
The calculation for wind energy economics is very simple, in that the cost/benefit analysis is fairly easy to perform. As with most cost/benefit analyses, we begin with the benefits. It makes no sense to calculate the costs of a system if there are no benefits, so we must determine first if there are any benefits.
Benefits are found from average output in kW multiplied by average hours per year of generation, multiplied by the average price per kWh for power sales.
1) $ = kW x hrs/y x $/kWh
Power from wind is given by the equation (2)
2) kW = 1/2 / 1000 x Eff x density x Area x Velocity ^3
Where W = Watts power produced
Eff = percent of available wind energy extracted by the turbine
density = air density, a constant usually at 1.225 kg/cubic meter
Area = swept area of the wind turbine blades, square meters
Velocity = wind speed in meters per second
For a sample calculation,
Eff = 0.4
Area = 5,026 sq meters (from a rotor 80 meters diameter)
Velocity = 16 meters per second (equivalent to 36 miles per hour)
Then kW = 0.5 /1000 x 0.4 x 1.225 x 5,026 x 16 ^3
kW = 5,044
For a location where wind blows an average of 7 hours per day, then hours per year is
3) hrs/y = 7 x 365 = 2555
If the average sales price is $0.075 per kWh, then
$ benefits per year = 5,044 x 2,555 x 0.075 = $967,000 (rounded to thousands)
We can then proceed to the cost side of the analysis, having established that a 5 MW wind turbine at that location would produce revenue of almost $1,000,000 per year.
For an investor, seeking a minimum return on his money of 10 percent before taxes, a simple method of screening a project is to determine the number of years required to payback the investment. Using 10 year payback period, then the investment can be:
4) Inv = 10 * 1,000,000 = $10,000,000
A check on the investment per kW of turbine output shows
5) $/kW = 10,000,000 / 5,000 = 2,000 (approximately)
This result, $2,000 per kW, compares favorably to that published by California Energy Commission for onshore wind projects with 2009 installation, where the cost was $1,990 per kW. It should be noted that wind turbine costs have declined considerably since then (only 5 years ago at this writing), with some sources indicating 30 percent decline. (end update 8/4/14)
The above provides the basic equations for computing wind power output, however, the turbine efficiency and wind speed are critical for individual project performance. In the US, there are actually few locations, if any, that have wind speed of 16 m/s (36 miles per hour) for 7 hours each day. Wind speed maps of the US are available; these show a typical range from zero to 10 m/s. Wind speed is also classified into 7 classes, 1 - 7, with good wind being in class 3 and 4, and excellent wind in class 5. These classes are for wind speed of 6.4 to 7.5 m/s for class 3 to 4, and from 7.5 to 8.0 m/s for class 5. In places offshore on both the Pacific and Atlantic coasts, wind averages 9 to 10 m/s. The great wind corridor from the Canadian border to central Texas, and extending from the Rocky Mountains east approximately 450 miles, has annual average wind speeds of approximately 9 m/s.
Using a value for class 7 wind, 9 m/s in the above equations, gives 894 kW, a factor of 5.6 times less than 5,044.
As always on SLB, comments are welcome however they must be on-topic, non-commercial, and respectful. All comments are moderated by Roger Sowell. Comments may not appear right away.
Copyright 2014, Roger E. Sowell
Following the success of a 30-article series on The Truth About Nuclear Power see link, this article begins a similar series on Truth About Wind Energy, TAWE. Arguments rage about wind power, with detractors making wild claims about high electric power costs, grid instabilities, unfair subsidies from government, death to flying birds and mammals, unsightly turbines blighting views, and others. Supporters show that wind has enormous potential to replace almost every other form of grid power, that grids operate stably and will be even better in the future, subsidies are found in other forms of power generation - especially nuclear power, there is an urgency to develop renewable power and global warming has nothing to do with it, and many other points that favor wind power.
This series of articles, planned to be approximately one dozen, takes the many arguments and looks at each one factually, with sound engineering, economics, legal aspects, and policy objectives.
This first article is a work in-progress, and will likely be modified from time to time. As with TANP articles, each article in the series will be linked at the bottom as it is published.
A first effort at topics for TAWE include: Is wind economic? Costs to install wind turbines? Annual output, capacity factor? What about subsidies? Technology types for turbines? Onshore vs Offshore potential? Impact on existing grids? Backup power supplies required? Experience shows us what? Emissions from backup plants? Impact on birds, bats? Safety – is anyone injured? Brief history of wind power? Longterm outlook for energy supplies? Time-shifting energy via storage and discharge? A concluding chapter.
Update: 8/4/2014 - Is wind economic?
The calculation for wind energy economics is very simple, in that the cost/benefit analysis is fairly easy to perform. As with most cost/benefit analyses, we begin with the benefits. It makes no sense to calculate the costs of a system if there are no benefits, so we must determine first if there are any benefits.
Benefits are found from average output in kW multiplied by average hours per year of generation, multiplied by the average price per kWh for power sales.
1) $ = kW x hrs/y x $/kWh
Power from wind is given by the equation (2)
2) kW = 1/2 / 1000 x Eff x density x Area x Velocity ^3
Where W = Watts power produced
Eff = percent of available wind energy extracted by the turbine
density = air density, a constant usually at 1.225 kg/cubic meter
Area = swept area of the wind turbine blades, square meters
Velocity = wind speed in meters per second
For a sample calculation,
Eff = 0.4
Area = 5,026 sq meters (from a rotor 80 meters diameter)
Velocity = 16 meters per second (equivalent to 36 miles per hour)
Then kW = 0.5 /1000 x 0.4 x 1.225 x 5,026 x 16 ^3
kW = 5,044
For a location where wind blows an average of 7 hours per day, then hours per year is
3) hrs/y = 7 x 365 = 2555
If the average sales price is $0.075 per kWh, then
$ benefits per year = 5,044 x 2,555 x 0.075 = $967,000 (rounded to thousands)
We can then proceed to the cost side of the analysis, having established that a 5 MW wind turbine at that location would produce revenue of almost $1,000,000 per year.
For an investor, seeking a minimum return on his money of 10 percent before taxes, a simple method of screening a project is to determine the number of years required to payback the investment. Using 10 year payback period, then the investment can be:
4) Inv = 10 * 1,000,000 = $10,000,000
A check on the investment per kW of turbine output shows
5) $/kW = 10,000,000 / 5,000 = 2,000 (approximately)
This result, $2,000 per kW, compares favorably to that published by California Energy Commission for onshore wind projects with 2009 installation, where the cost was $1,990 per kW. It should be noted that wind turbine costs have declined considerably since then (only 5 years ago at this writing), with some sources indicating 30 percent decline. (end update 8/4/14)
The above provides the basic equations for computing wind power output, however, the turbine efficiency and wind speed are critical for individual project performance. In the US, there are actually few locations, if any, that have wind speed of 16 m/s (36 miles per hour) for 7 hours each day. Wind speed maps of the US are available; these show a typical range from zero to 10 m/s. Wind speed is also classified into 7 classes, 1 - 7, with good wind being in class 3 and 4, and excellent wind in class 5. These classes are for wind speed of 6.4 to 7.5 m/s for class 3 to 4, and from 7.5 to 8.0 m/s for class 5. In places offshore on both the Pacific and Atlantic coasts, wind averages 9 to 10 m/s. The great wind corridor from the Canadian border to central Texas, and extending from the Rocky Mountains east approximately 450 miles, has annual average wind speeds of approximately 9 m/s.
Using a value for class 7 wind, 9 m/s in the above equations, gives 894 kW, a factor of 5.6 times less than 5,044.
Roger E. Sowell, Esq.
Marina del Rey, California
As always on SLB, comments are welcome however they must be on-topic, non-commercial, and respectful. All comments are moderated by Roger Sowell. Comments may not appear right away.
Copyright 2014, Roger E. Sowell
The Truth About Nuclear Power – Part 30
Subtitle: Conclusion on Nuclear Power Not Economic Nor Safe
This is the 30th and final chapter in the Truth
About Nuclear Power series, (see links at end of article) at least for now.
The TANP series was motivated by many conversations and digital
exchanges via emails and online blogs over several years, in which most nuclear
advocates advanced various statements about the advantages of nuclear
power. Knowing that those statements
were false, I answered many of the false statements.
For those who have read some of or the entire TANP series, this
concluding article will serve as a review and provide (hopefully) further
insight into the actual world of nuclear power.
The article is in three parts: 1) the rosy claims of nuclear advocates,
2) questions raised by those rosy claims, and responses to the questions
raised, and 3) an answer for why nations continue to build nuclear plants
despite the serious and numerous disadvantages.
Part I of this article discusses nuclear advocates’ six
primary claims, those being that nuclear power is 1) cheap, only 2 or 3 cents per kWh, 2) reliable, and 3) extremely safe; they insist
that 4) the plants run for 60 years before needing replacement, and 5) cost
only $2.5 to $4 billion per 1,000 MW plant.
They also insist 6) the plants are built in only 4 years from
groundbreaking to startup. None of that
squares with what I know about nuclear plants.
Part II of this article addresses a series of questions
about nuclear power, the answers to which led to many of the previous articles
on TANP. The general form of the
questions is, If what nuclear advocates say is really true, then Why (insert
the question) is this also true? These
questions are shown below:
1 Why has nuclear power achieved only 11 percent of world
power production, after more than 5 decades of competition?
2 Why do small
islands have zero nuclear power plants, but burn expensive oil or diesel
resulting in power prices of 25 to 35 cents per kWh?
3 Why do nuclear utilities never, ever, ask for a rate
decrease when they build a nuclear plant?
4 Why did France
install nuclear plants to provide 85 percent of the country’s power, and no
other country in the world followed their lead?
5 Why does France
have higher electricity prices than does the US, even with France heavily
subsidizing their electricity industry?
6 Why does nuclear
power in the US require heavy subsidies from government – and almost total
indemnity from costs of a massive radiation disaster?
7 Why are nuclear
plants shutting down in the US, with owners saying they are losing money?
8 Why are there so
many near-misses on meltdowns in US plants, every 3 weeks?
9 Why were there
three serious meltdowns worldwide in just a bit more than 30 years? (Fukushima,
Chernobyl, Three Mile Island)
10 Why are new
reactor technologies being researched and developed?
Part III of this article poses, then answers, the additional
question of Why do countries around the world continue to build nuclear power
plants, in spite of all the obvious, documented, irrefutable disadvantages of
nuclear power?
I Rosy Claims of
Nuclear Advocates
Nuclear advocates assert six primary claims, those being that
nuclear power is 1) cheap, only 2 or 3
cents per kWh, 2) reliable, 3) extremely
safe; they insist that 4) the plants run for 60 years before needing
replacement, and 5) cost only $2.5 to $4 billion per 1,000 MW plant. They also insist 6) the plants are built in
only 4 years from groundbreaking to startup. None of that squares with what I know about
nuclear plants.
The reality is quite different. Taking their assertions in turn, nuclear
power is cheap only if one counts the fuel costs but ignores all the capital costs,
operations and maintenance, insurance, taxes, and other costs of owning and
running a plant. There is a fundamental
fact that energy from nuclear fission is quite large, given the amount of
uranium that is split into smaller atoms.
However, no one prices a product simply on the fuel costs – for example,
renting a moving van typically has a fixed cost per day plus a cost for miles
driven, plus costs of insurance, plus the renter must pay for fuel used. As another example, renting a home or
apartment typically includes a fixed cost per month for use of the home, plus
costs for utilities including electricity, natural gas, water, trash removal, communications
(phone service and internet service), and insurance. It is misleading and deceptive for nuclear
advocates to claim that nuclear power is cheap, based solely on fuel costs.
Next, nuclear plants are claimed to be reliable. At times, they are reliable – but only when
they are running. TANP Part 16 shows
that in the US, nuclear plants were shut down on an emergency basis
approximately once every 3 weeks over a four-year period. Those
incidents were serious, so much so that the NRC sent an investigative team to
those plants. There were actually far
more unplanned shutdowns, each of which shows the plants are not as reliable as
advocates claim. The NRC, for safety
reasons, requires nuclear plants to shut down for many reasons until the safety
issue is resolved. The plants also
experience routine equipment failures, both on the nuclear and non-nuclear
sides of the plant. When the nuclear
plant trips off-line, the other power plants on the local grid must make up the
loss of power, or the electrical demand must be reduced. A very
recent example of loss of nuclear power is the total and permanent shutdown of
the San Onofre Nuclear Generating Station (SONGS) in Southern California in
2012. The plant was shut down without
warning due to a serious radioactive steam leak into the atmosphere. This was discussed in TANP Part 23. The twin reactors were producing
approximately 2100 MW into the grid. All
that power had to be replaced quite suddenly.
Next, nuclear plants are claimed to be extremely safe. Several articles on TANP address the safety
issues, including Part 16 mentioned just above, showing the plants shut down
approximately every 3 weeks in the US to prevent a serious malfunction. The three major meltdowns, Three Mile
Island, Chernobyl, and Fukushima Dai-Ichi were discussed in one article each on
TANP. Evacuation plans required at each
plant are discussed in Part 26. The
fundamentally unsafe nature of nuclear plants, and the incredibly high risk and
consequent damages from a major incident are discussed in several articles,
including Part 5, and 6. Medical risks
to populations are discussed in Part 19.
Reprocessing spent fuel and the safety issues associated are discussed
in Part 18. An example is described in Part 16, where the short-lived Rancho Seco nuclear plant near
Sacramento, California, was shut down permanently after only 18 years of
operation (1971 - 1989) due to an incredible number of leaks, radiation
emissions, fires, mechanical breakdowns, and other safety issues.
Next, nuclear plants are claimed to run for 60 years before
replacement. This assertion is simply
not true; the Rancho Seco plant mentioned just above lasted only 18 years,
while the two reactors at SONGS plant lasted just under 30 years. The Three Mile Island Reactor 2 melted down
after only one year of operation. Per
the NRC, at this time the oldest US operating reactors are 44 years old. Of the
28 shutdown nuclear reactors in the US, none made it to 60 years before
shutdown.
Next, nuclear plants are claimed to cost only $2.5 to $4
billion per 1,000 MWe output. This is
again a similar misstatement, in that it incorporates only the theoretical
cost, the “overnight” cost and does not include the realities of a multi-year
construction period, cost escalations due to inflation on materials and labor,
and the interest on construction loan.
As shown in Part 3, 6, and 9, the actual cost to construct a modern
nuclear power plant is approximately $10 billion for a 1,000 MWe output.
Finally, advocates claim that nuclear plants are built in
only 4 years from groundbreaking to startup.
The reality is that almost every nuclear power plant requires far more
than 4 years, with many requiring 10 years or longer to build. Even today, a new reactor in Finland and a
similar one in France are years behind schedule, the Vogtle plant in Georgia (US) is also years behind
schedule. The South Texas plant was
several years behind schedule when it started operating.
Watts Bar unit 1 required 23 years from start to completion.
II A Series of Questions
Ten questions came to mind in response to the nuclear
advocates’ position on nuclear power, which are discussed in turn below. From above, the general form of each question
is, If what nuclear advocates say is really true, then Why (insert the
question) is this also true? These
questions are shown and discussed below.
1 Why has nuclear power achieved only 11 percent of world
power production, after more than 5 decades of competition?
The reality is that, even after 50 years or more of design,
development, actual experience, fine-tuning, and making best efforts around the
world, nuclear power (as of 2011 per EIA statistics, see TANP part 11) provides
only 11.7 percent of all power world-wide.
The only technologies smaller than nuclear’s share are oil (4.8 percent)
and a catch-all category (4.5 percent) that includes wind, solar, geothermal,
and various other renewable power. One would expect that nuclear, if it were
truly a superior technology economically and safe, would have easily surpassed
coal, natural gas, and hydroelectric power (41, 22, and 16 percent
approximately, respectively). Nuclear
power, in the US and in the early 70’s, was seen as a cheap way to replace
oil-fired power plants that were suddenly losing money after world oil prices
increased in the Oil Embargo. Until that
time, oil provided about 20 percent of US power. Nuclear plants replaced that oil-based power
almost on a one-for-one basis. However,
when nuclear plants had to compete with lower-cost technologies, coal and
natural gas, they could not.
2 Why do small
islands have zero nuclear power plants, but burn expensive oil or diesel
resulting in power prices of 25 to 35 cents per kWh?
This is discussed at length in TANP part 12. It is quite instructive that islands around
the world, particularly those 15 islands with populations that support a power
demand of approximately 1000 MW, have zero nuclear power plants. If nuclear power was truly as cheap as the
advocates claim, then why are islanders burning fuel oil and diesel in
generators to produce power that costs them 25 to 35 cents per kWh (or
more)? Surely, the islanders are not
stupid. The simple fact is that
islanders are quite smart, and are using the best technology available to
provide power at the lowest cost consistent with reliability and safety. Nuclear advocates seethe over this point, and
sneeringly reply that England must not be an island, then, nor Taiwan, nor
Japan (several islands actually), since they all have nuclear power
plants. However, the point is that small
islands, those with populations of approximately 1 million, have expensive
power but zero nuclear plants.
3 Why do nuclear utilities never, ever, ask for a rate
decrease when they build a nuclear plant?
If nuclear power truly was as low-cost as the advocates
claim, why then do utilities always request a rate increase when building a nuclear
plant? In all my research over many
decades, I have yet to find a single utility that asked for a rate decrease
after building a nuclear plant. Indeed,
today in Georgia (US), the utility had to request the legislature and Governor
to change the law so that the utility could charge existing customers more
money in order to build the Vogtle nuclear plant. The utilities have gone from asking for
money after the plant is built, to asking for money during construction. At times, utilities have asked for so much
money in the rate increase that lawsuits were required to settle how much of
the cost to build nuclear could be obtained from the customers, and how much
the utility had to absorb.
The natural consequences of building nuclear plants is higher
and higher power prices. Grim
consequences of this are discussed at length in TANP part 2.
4 Why did France
install nuclear plants to provide 85 percent of the country’s power, but no
other country in the world followed their lead?
This fact, France having 85 percent nuclear power on their
grid, is frequently thrown out by nuclear advocates to show that nuclear power
is the best power choice, and that other countries would do well to follow
France’s lead. The reality is quite
different. This is discussed at length
in TANP part 11. France has few fossil
fuel resources (at least up until now when natural gas is widely available but
un-tapped via hydraulic fracturing and directional drilling). Power before 1974 was provided by oil-burning
power plants, using imported oil. The
OPEC oil embargo raised oil prices so much that France chose to build nuclear
plants rather than import oil. This is a
theme that will be considered in greater detail in Part III of this concluding
article.
5 Why does France
have higher electricity prices than does the US, even with France heavily
subsidizing their electricity industry?
As shown in part 11, France had to subsidize its power
industry, and must to this day sell excess power at night to other countries
(primarily Italy) to avoid reducing the nuclear plants’ output each night and
increasing again each day. Only with
the Italians’ cooperation is this possible.
France has also been found in violation of illegally subsidizing its
power prices. Finally, even with vast
subsidies, France charges its customers between 50 percent and 100 percent more
(essentially double) for electric power compared to prices in the US. This is hardly a roadmap for anyone else to
follow. Indeed, no other country follows
France in building so great a share of nuclear power on its grid. After 40 years from the Oil Embargo, if it
were a good idea, surely some other country would have done so.
6 Why does nuclear
power in the US require heavy subsidies from government – and almost total
indemnity from costs of a massive radiation disaster?
As shown in great detail in part 13 and 25, US nuclear power
plants enjoy massive subsidies. In fact,
no nuclear plant would be built without the subsidies. Forms of subsidy include construction loan
guarantees, liability relief from property and human injuries due to radiation
disasters, relief from some construction lawsuits, a form of a carbon tax that
shuts down their coal-based competition, and as mentioned earlier, legislation
to force rate-payers to pay for nuclear power plant construction before the
plants are completed. In fact, the Price-Anderson Act provides that
nuclear plant owners carry insurance for $300 million in damages, and each operating
plant must contribute to anything above $300 million. The federal government pays anything above a
stated amount, presently about $10 billion.
In effect, the nuclear power plant owners have almost zero liability due
to insurance and government indemnity.
This cannot be conducive to a safe operating regime – if there are zero
consequences, why try to operate safely?
7 Why are nuclear
plants shutting down in the US, with owners saying they are losing money?
As shown in TANP part 1, almost a dozen US nuclear power
plants have either announced their intention to shut down, or are losing money
while operating. Nuclear utilities are
pleading with lawmakers to pass laws to provide government subsidies to the
nuclear plants. This is due to the fact
that nuclear power is not the most economic choice for power generation.
In fact, it is a losing proposition. Nuclear power plants almost always
run at 100 percent output or close to that, meaning they do not reduce output
at night when demand for power is lowest. Their cash operating costs, for
items such as labor, fuel, and consumables like water and chemicals, are higher
than the price the grid operator will pay them. The fact that they
do not reduce output at night forces them to compete with themselves, putting
an unwanted and un-needed product into the market, driving down the prices. Exelon, the owner of more US reactors (23)
than any other company, has publicly sought government intervention to prop up
its sales prices – in an effort to “save jobs.”
8 Why are there so
many near-misses on meltdowns in US plants, every 3 weeks?
The nuclear industry, and nuclear advocates, try to avoid
discussing the serious and frequent near-misses in the US nuclear reactor
fleet. However, the information is
publicly available and is compiled and published annually. The results for the four years 2010-2013,
inclusive, are discussed in part 16.
There were 70 serious incidents in the four years, for an average of
approximately one every 3 weeks. There
were many more incidents but these 70 resulted in an investigative team sent to
the plant by the NRC. Nuclear power
plants are a tragedy waiting to happen. From design issues that are only now
discovered (many 40 years after startup), to replacement parts that do not work
smoothly with the other plant systems, to untrained operators, to normal
equipment failures responded to badly, to unanticipated combination of system failures,
the list of causal events goes on and on.
The most serious incident, in my view, occurred at the Byron
Station, Unit 2, in January, 2012, in Illinois. A complete loss of
cooling water at Unit 2 was temporarily replaced with water from Unit 1. Had
this been a single-reactor plant, with no operating reactor close at hand, the
loss of cooling could have resulted in a partial or full core meltdown, exactly
what happened at Fukushima, Japan, and at Three Mile Island. This is
completely unacceptable.
Nuclear advocates, though, argue that the safety systems are adequate since no meltdowns occurred recently. However, the sheer number of serious incidents shows that eventually, another catastrophe will occur. The US has been lucky, but that luck is likely running out as the plants grow older and more mishaps occur.
Nuclear advocates, though, argue that the safety systems are adequate since no meltdowns occurred recently. However, the sheer number of serious incidents shows that eventually, another catastrophe will occur. The US has been lucky, but that luck is likely running out as the plants grow older and more mishaps occur.
9 Why were there
three serious meltdowns worldwide in just a bit more than 30 years? (Fukushima,
Chernobyl, Three Mile Island)
This question is about the most serious disasters thus
far. Each is well-known, and has been in
the world news. Each meltdown has its
own article in TANP, Three Mile Island is article 21, Chernobyl is article 20,
and Fukushima is article 22. In spite
of the claims to safety, Three Mile Island resulted in a core meltdown that
almost broke through the reactor walls. That would most assuredly resulted in a
hydrogen explosion and containment building destruction – with radiation spread
over a wide area near the northern US East Coast. Only pure dumb luck prompted an operator to
re-start a water pump that had been deliberately shut down earlier. That additional water began cooling the
melting core. Chernobyl’s explosion was
the result of a badly planned and executed test with the reactor far from
acceptable conditions. The Fukushima
multiple reactor meltdowns and containment building explosions were due to
total loss of all grid power for days and days, following an earthquake that slightly
exceeded design conditions plus a tsunami that far exceeded design
conditions. Each time a major incident occurs such as
those three, the industry shrugs it off with sayings such as
“that was a coincidence,” or “that can never happen again” or something similar. Yet, the stark fact is that in just over 30 years, there have been 3 major meltdowns, (five if Fukushima’s 3 reactors are counted separately), with 4 exploded containment buildings.
“that was a coincidence,” or “that can never happen again” or something similar. Yet, the stark fact is that in just over 30 years, there have been 3 major meltdowns, (five if Fukushima’s 3 reactors are counted separately), with 4 exploded containment buildings.
10 Why are new
reactor technologies being researched and developed?
This ties in with the earlier questions on nuclear
economics, and to an extent, reactor safety.
If present nuclear technology was truly cheap, and truly safe, there
would be no need to explore alternatives.
Yet, several countries are developing technologies including small
modular reactors (SMR), fusion, thorium molten salt reactors, and high
temperature gas reactors. Each of these
has an article on TANP, (8, 27, 28, and 29 respectively). The conclusion for each technology is that
the economics are even worse than present large-scale PWR (pressurized water
reactor) designs, and each has serious safety issues. The SMR
companies in the US have recently curtailed their activities due to lack of
investment and lack of customers. The
market-place has voted with its pocketbook, and the vote was “no sale.” Fusion is proceeding in research but has so
many drawbacks it is almost a tragedy.
They plan to split water into hydrogen and oxygen, isolate deuterium
from normal hydrogen, freeze the deuterium, make spherical pellets of the
deuterium, then load the sphere into a special chamber where high-powered
lasers blast simultaneously on the sphere’s surface to induce a fusion reaction
at the sphere’s core. If it were not
published by a US national lab, this would be the stuff of comic books and a
mad scientist. Thorium in a molten salt has so many technical
and safety issues it will likely never be approved by a regulatory agency. The same is true with HTGR, where uranium is
enclosed in 2.5-inch spheres that are to be injected via a lock-hopper into a
hot nuclear reactor at 1000 psi and more than 1000 degrees F.
III Why Countries Continue to Build Nuclear Power Plants
Many more nuclear plants are under construction, or planned,
in spite of all the obvious, documented, irrefutable disadvantages of nuclear
power. Most are not in the US, instead
they are in many other countries including China, India, Finland, France, and
others. It is helpful to examine the
alternatives for generating power in various countries.
First, the US has perhaps the lowest cost of natural gas of
any major economy due to extensive directional drilling and hydraulic
fracturing of gas-bearing strata deep underground. Most other countries pay a price for natural
gas that is on parity with the fuel-equivalent value of oil. In today’s dollars, oil is approximately $100
per barrel, the equivalent of $17 per million Btu. Natural gas in the US is presently $3 to $4
per million Btu, while in other countries it is $15 to $17 per million
Btu. A recent and major supply contract
from Russia to China has the price of gas tied to the price of oil; as oil
price increases, so does natural gas.
Even with a high-efficiency natural gas power plant that
uses combined cycle technology, the fuel component of power is approximately
one-half the price of the natural gas.
Therefore, with gas at $17 per million Btu, power must be sold for at
least $90 per MWh (9 cents US per kWh).
Capital costs and other operating, maintenance and miscellaneous costs
add another $20 to $30, with the resulting price to the grid of $110 to $120
per MWh. This price is what a nuclear
plant must compete with, in non-US countries.
Indeed, it is instructive that recent projects for nuclear
power plants have a sales price for power of almost exactly as shown
above. India, for example, obtained a
price of $100 per MWh in negotiations with France-based Areva where Areva
wanted $160 per MWh. That same project
has a sweetheart interest rate of 4.8 percent from France to India for the construction
loan. Russia also sweetens nuclear
plant deals with below-bank financing.
Countries also are not pleased with natural gas imports,
especially when the gas supplier has a tendency to shut off the gas supplies. Russia has done this to its gas
customers. Perhaps it is better, the
thinking goes, to have nuclear plants provide the power and not risk having the
gas shut off in a cold winter.
It is also a consideration that balance of trade, the high
cost of importing vast quantities of oil or natural gas, can have an effect on
a national economy. That is the reason
France has advanced for switching to nuclear in the 1970s.
Finally, it may be that different countries evaluate the
safety risk and conclude that nuclear plants are sufficiently safe, given
proper design and when located away from earthquake zones and tsunami
areas.
Conclusion
Finally, it has been shown throughout the TANP series that
nuclear power is not economic – many citations are documented. Nuclear power is not safe either – again many
citations are documented. Despite this,
many countries are building nuclear plants and plan to build even more. Their reasons to build nuclear may satisfy
them, but it is very interesting to note why nuclear cannot compete in the US:
the price of natural gas is too low.
Many other countries, France included, also have vast resources of
natural gas locked away in shale deposits that can be developed (as is the US)
using directional drilling and hydraulic fracturing. Producing such gas reserves domestically
would reduce the price of natural gas, perhaps far below the oil-based pricing
currently prevailing.
As Germany reacted to the Fukushima disaster, declaring
nuclear power a menace that will be shut down as soon as possible, other
countries will very likely take the same decision. While not wishing any ill effects on anyone
anywhere, only one more major disaster such as Fukushima meltdowns and
radiation release, would tip the scales in balance of no more nuclear
power.
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.
Part One – Nuclear Power Plants Cannot Compete
Part Three – Nuclear Power Plants Cost Far Too Much to Construct
Part Four – Nuclear Power Plants Use Far More Fresh Water
Part Five – Cannot Simply Turn Off a Nuclear Power Plant
Part Six – Nuclear Plants are Huge to Reduce Costs
Part Seven -- All Nuclear Grid Will Sell Less Power
Part Eight – No Benefits from Smaller Modular Nuclear Plants
Part Nine -- Nuclear Plants Require Long Construction Schedules
Part Eleven - Following France in Nuclear Is Not The Way To Go
Part Thirteen - US Nuclear Plants are Heavily Subsidized
Part Fourteen - A Few More Reasons Nuclear Cannot Compete
Part Fifteen - Nuclear Safety Compromised by Bending the Rules
Part Sixteen - Near Misses on Meltdowns Occur Every 3 Weeks
Part Seventeen - Storing Spent Fuel is Hazardous for Short or Long Term
Part Eighteen - Reprocessing Spent Fuel Is Not Safe
Part Fourteen - A Few More Reasons Nuclear Cannot Compete
Part Fifteen - Nuclear Safety Compromised by Bending the Rules
Part Sixteen - Near Misses on Meltdowns Occur Every 3 Weeks
Part Seventeen - Storing Spent Fuel is Hazardous for Short or Long Term
Part Eighteen - Reprocessing Spent Fuel Is Not Safe
Part Nineteen - Nuclear Radiation Injures People and Other Living Things
Part Twenty - Chernobyl Meltdown And Explosion
Part Twenty One - Three Mile Island Unit 2 Meltdown 1979
Part Twenty Two - Fukushima The Disaster That Could Not Happen
Part Twenty Three - San Onofre Shutdown Saga
Part Twenty Four - St Lucie Ominous Tube Wear
Part Twenty Five - Price-Anderson Act Protects Nuclear Plants Too Much
Part Twenty Six - Evacuation Plans Required at Nuclear Plants
Part Twenty Seven - Power From Nuclear Fusion
Part Twenty-Eight - Thorium MSR No Better Than Uranium Process
Part Twenty-Nine - High Temperature Gas Reactor Still A Dream
Part Thirty - this article Roger E. Sowell, Esq.
Marina del Rey, California
Friday, August 1, 2014
The Truth About Nuclear Power - Part 29
Subtitle: High Temperature Gas Reactor Still A Dream
This is the final article in the Truth About Nuclear Power series that discusses alternatives to the uranium fission process via the large Pressurized Water Reactor design, PWR. Earlier articles discussed the failings and disadvantages of small modular reactors, fusion reactors, and thorium reactors. This article discusses the hopes and disadvantages of the High Temperature Gas Reactor, which has been in development for decades. As with the other alternatives mentioned above, the very fact that such alternatives are researched gives the lie to the assertion that nuclear power is economic. If it were economic in any form, it would have already captured far, far more than the 11 percent (approximately) of the world’s electric power generation. Still, HTGR is yet another design that its advocates hope will be safe, economic, and the power plant of the future. Each of the HTGR components, and the system as a whole, will be described. The disadvantages are highlighted.
Basic Design
The HTGR can be designed in a few variations, the one that is discussed here has a nuclear reactor using small spheres to heat a circulating gas of high-pressure helium. The hot helium passes through a gas turbine that spins a generator to produce electricity. The exhaust helium from the gas turbine is still relatively hot, and passes through a series of heat exchangers in which the helium is cooled. The cool, low-pressure helium then is compressed in a compressor, typically in two stages with gas intercooling between stages. The compressor or compressors are also driven by the gas turbine described above. Hot, high-pressure helium from the second stage gas compressor is further heated against turbine outlet helium (one of the series of heat exchangers described above). Finally, completing the circulation loop, the hot high-pressure helium enters the nuclear reactor to absorb more heat.
The reactor is a complex chamber, almost certainly a vertical cylinder with thick walls and heads to contain the pressure and radiation. The reactor contains hundreds of thousands of radioactive spheres, known as pebbles, each approximately 2.5 inches diameter. The pebbles contain a core of fissile uranium with the uranium itself in thousands of microspheres. The pebble also has various layers of other materials, including graphite, to act as a neutron moderator and maintain the uranium’s integrity. The number of microspheres per reactor is on the order of 1 billion (10^9).
Pebble management is accomplished by adding fresh pebbles at the reactor top, and withdrawing pebbles from the bottom of the reactor. Heat output is regulated by control rods that extend vertically from the reactor top down into the bed of pebbles.
The claimed advantages are a high overall efficiency of approximately 50 percent, an inherently safe nuclear reaction that cannot under any circumstances melt down, and low cost.
A paper from the NRC from 2011 discusses the then-state-of-the-research; see link.
Finally, a report from 2004 by General Atomics describes the several highly radioactive, toxic, isotopes that are routinely produced and transported out of the HTGR reactor and into the circulating helium loop. A helium loop rupture would have dire consequences. See link. (note, this link downloads the article)
Disadvantages
Whenever one sees a research proposal that involves inserting discrete material (in this case, pebbles) into a high-pressure system (the reactor at 1,000 psi), one must pause. The fact is, even with many decades of effort by talented and motivated engineers, the material feed hopper design has not been found that is sufficiently reliable to obtain high on-stream factors. In other words, moving the pebbles from atmospheric pressure into a lock hopper, pressurizing the lock hopper without blowing any seals, and dropping the pebbles by gravity into the high-pressure reactor simply has proven too difficult. One reference shows the pebble bed reactor operating in a research mode from 1967. That is almost 50 years ago (47 years at this writing).
With a mass of pebbles in the reactor, coaxing the spent pebbles out while keeping the live pebbles inside is a daunting task. With a hot, radioactive, 1000 psi reactor, it is indeed difficult to persuade any living being to step up and sort them out. Perhaps that can be a job for a radiation-tolerant robot.
The reactor will be very expensive, as in PWR reactors, due to the high pressure, high temperature, and radiation.
Keeping the pebbles from forming dead zones, where helium gas does not pass with sufficient velocity to remove the heat generated by fission, is also a monumental task. It is claimed by the HTGR advocates that the pebbles are completely safe and cannot meltdown even with zero cooling and all the control rods removed. One must pause at that statement, and ask exactly how did they arrive at that conclusion? Was the experiment performed? Did anyone take an actual, full-scale reactor full of radioactive pebbles, not necessarily new but at the worst possible condition, turn off the cooling and remove all the control rods? It is highly doubtful that the NRC (or any other responsible regulatory agency in any country) would have allowed such a full-scale test. Even if the pebbles cannot meltdown, there must be provided some means to remove the residual heat from the reactor. The materials used to form the reactor walls, heads, and internal structures will likely lose strength as the nuclear reactions proceed. It appears from the design that the three levels of containment are incorporated: the pebble itself is the first barrier to uranium, then the reactor vessel is the second, and the third is a containment building in which the reactor is placed. Yet more expense is required to build a suitable containment building.
Next, the closed-loop helium cycle consumes a substantial amount of power in the compression stages. In contrast to a natural gas-fired turbine, the HTGR must compress all of the helium. A gas-fired turbine compresses only the air that is burned with the natural gas. Therefore, the HTGR is automatically at a disadvantage from the requirement to compress all the gas that flows through the system. Also, since helium is a very low molecular weight gas, the compressor must “work harder” to achieve the same discharge pressure. This requires a larger compressor, and more capital to build and install it. Finally, operating high-pressure and high-temperature gas compressors on helium requires very sophisticated seals to prevent helium leaking into the atmosphere.
The very largest gas turbines to date, operating on natural gas and air, produce approximately 350 MWe. Blade temperatures and blade tip speeds inside the turbine are the limiting factors. Therefore, even if the reject heat is used to produce steam that produces electricity in a separate steam turbine and generator, nuclear HTGR will have approximately 500 MW output. Economy of scale begins to work against the plant. This effectively means HTGR can never, ever, be economic.
Next, the system relies on at least one gas-to-gas heat exchanger, which is inherently expensive because gas has a very low heat transfer coefficient. In essence, the exchanger must be huge to transfer the heat required. In addition, the gas-to-gas heat exchanger must be designed to withstand 1000 psi pressure, at relatively high temperature of approximately 1000 deg. F. The high pressure and high temperature also increase the cost. At least two additional helium gas heat exchangers transfer heat against other fluids, presumably cooling water in one instance, and unspecified fluid in the other. These also will have large areas because the gas, as before, has very low heat transfer coefficient. Leakage from tubes must be monitored closely to prevent any material from entering the helium loop.
Next, a reactor vessel rupture or helium piping rupture could send radioactive, hot, balls 2-1/2 inch diameter flying under 1000 psi pressure. Such an event must be considered, designed for, and mitigated as much as possible.
Next, long-term storage of spent fuel pebbles remains a problem.
Next, production of radionuclides from the reactor, transport of those radionuclides into the helium gas circulation loop, and release into the atmosphere in the event of a pipe or system rupture, is a very serious issue.
Finally, the NRC has identified an issue with graphite dust production and transport. This can be an extremely serious issue, as graphite is a form of carbon. Graphite dust is highly flammable and explosive in the proper concentrations.
Previous Experience
A South Africa HTGR reactor was cancelled due to cost overruns, schedule pushed back, and insurmountable technical problems. A project in Germany was also cancelled. Two research reactor projects in the US were also cancelled, one in the early 1970s and the other in the 1980s. The latter plant, at 330 MWe, was likely not merely for research due to the rather impressive size. However, it was shut down due to recurring mechanical problems and what was described as “poor performance.”
The South African experience is described at this link.
Conclusion
The HTGR nuclear reactor system has, as described above, many serious technical challenges that must be overcome. Given the dismal experience in other industries with similar reactors operating at high pressure that attempt to inject a solid into the reactor, it is not surprising that the HTGR reactors also fail. It is true that low-pressure systems can be made to work, but the high-pressure ball injection and removal systems are problematic. The high cost of every component is also a factor. The inherently small electrical output will forever keep the plants from enjoying economy of scale – at least until another advance is made in the gas-turbine and compressor technology. The large size of the heat exchangers adds to the cost, primarily due to the low heat transfer coefficient of the helium gas. This is an immutable characteristic of gas heat exchange, and has been known for many decades. The dismal experience of researchers in several countries over several decades does not bode well for the future of HTGR. The most important issues, though, are the production of explosive graphite dust, and production of lethal radionuclides in the reactor that are transported into the helium circulation loop that includes the heat exchangers, turbine, and compressors.
As with the other new designs, small modular reactors, fusion, and thorium, HTGR is also a very distant pipe dream.
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.
Part Thirty - Conclusion
Roger E. Sowell, Esq.
Marina del Rey, California
This is the final article in the Truth About Nuclear Power series that discusses alternatives to the uranium fission process via the large Pressurized Water Reactor design, PWR. Earlier articles discussed the failings and disadvantages of small modular reactors, fusion reactors, and thorium reactors. This article discusses the hopes and disadvantages of the High Temperature Gas Reactor, which has been in development for decades. As with the other alternatives mentioned above, the very fact that such alternatives are researched gives the lie to the assertion that nuclear power is economic. If it were economic in any form, it would have already captured far, far more than the 11 percent (approximately) of the world’s electric power generation. Still, HTGR is yet another design that its advocates hope will be safe, economic, and the power plant of the future. Each of the HTGR components, and the system as a whole, will be described. The disadvantages are highlighted.
Basic Design
The HTGR can be designed in a few variations, the one that is discussed here has a nuclear reactor using small spheres to heat a circulating gas of high-pressure helium. The hot helium passes through a gas turbine that spins a generator to produce electricity. The exhaust helium from the gas turbine is still relatively hot, and passes through a series of heat exchangers in which the helium is cooled. The cool, low-pressure helium then is compressed in a compressor, typically in two stages with gas intercooling between stages. The compressor or compressors are also driven by the gas turbine described above. Hot, high-pressure helium from the second stage gas compressor is further heated against turbine outlet helium (one of the series of heat exchangers described above). Finally, completing the circulation loop, the hot high-pressure helium enters the nuclear reactor to absorb more heat.
The reactor is a complex chamber, almost certainly a vertical cylinder with thick walls and heads to contain the pressure and radiation. The reactor contains hundreds of thousands of radioactive spheres, known as pebbles, each approximately 2.5 inches diameter. The pebbles contain a core of fissile uranium with the uranium itself in thousands of microspheres. The pebble also has various layers of other materials, including graphite, to act as a neutron moderator and maintain the uranium’s integrity. The number of microspheres per reactor is on the order of 1 billion (10^9).
Pebble management is accomplished by adding fresh pebbles at the reactor top, and withdrawing pebbles from the bottom of the reactor. Heat output is regulated by control rods that extend vertically from the reactor top down into the bed of pebbles.
The claimed advantages are a high overall efficiency of approximately 50 percent, an inherently safe nuclear reaction that cannot under any circumstances melt down, and low cost.
A paper from the NRC from 2011 discusses the then-state-of-the-research; see link.
Finally, a report from 2004 by General Atomics describes the several highly radioactive, toxic, isotopes that are routinely produced and transported out of the HTGR reactor and into the circulating helium loop. A helium loop rupture would have dire consequences. See link. (note, this link downloads the article)
Disadvantages
Whenever one sees a research proposal that involves inserting discrete material (in this case, pebbles) into a high-pressure system (the reactor at 1,000 psi), one must pause. The fact is, even with many decades of effort by talented and motivated engineers, the material feed hopper design has not been found that is sufficiently reliable to obtain high on-stream factors. In other words, moving the pebbles from atmospheric pressure into a lock hopper, pressurizing the lock hopper without blowing any seals, and dropping the pebbles by gravity into the high-pressure reactor simply has proven too difficult. One reference shows the pebble bed reactor operating in a research mode from 1967. That is almost 50 years ago (47 years at this writing).
With a mass of pebbles in the reactor, coaxing the spent pebbles out while keeping the live pebbles inside is a daunting task. With a hot, radioactive, 1000 psi reactor, it is indeed difficult to persuade any living being to step up and sort them out. Perhaps that can be a job for a radiation-tolerant robot.
The reactor will be very expensive, as in PWR reactors, due to the high pressure, high temperature, and radiation.
Keeping the pebbles from forming dead zones, where helium gas does not pass with sufficient velocity to remove the heat generated by fission, is also a monumental task. It is claimed by the HTGR advocates that the pebbles are completely safe and cannot meltdown even with zero cooling and all the control rods removed. One must pause at that statement, and ask exactly how did they arrive at that conclusion? Was the experiment performed? Did anyone take an actual, full-scale reactor full of radioactive pebbles, not necessarily new but at the worst possible condition, turn off the cooling and remove all the control rods? It is highly doubtful that the NRC (or any other responsible regulatory agency in any country) would have allowed such a full-scale test. Even if the pebbles cannot meltdown, there must be provided some means to remove the residual heat from the reactor. The materials used to form the reactor walls, heads, and internal structures will likely lose strength as the nuclear reactions proceed. It appears from the design that the three levels of containment are incorporated: the pebble itself is the first barrier to uranium, then the reactor vessel is the second, and the third is a containment building in which the reactor is placed. Yet more expense is required to build a suitable containment building.
Next, the closed-loop helium cycle consumes a substantial amount of power in the compression stages. In contrast to a natural gas-fired turbine, the HTGR must compress all of the helium. A gas-fired turbine compresses only the air that is burned with the natural gas. Therefore, the HTGR is automatically at a disadvantage from the requirement to compress all the gas that flows through the system. Also, since helium is a very low molecular weight gas, the compressor must “work harder” to achieve the same discharge pressure. This requires a larger compressor, and more capital to build and install it. Finally, operating high-pressure and high-temperature gas compressors on helium requires very sophisticated seals to prevent helium leaking into the atmosphere.
The very largest gas turbines to date, operating on natural gas and air, produce approximately 350 MWe. Blade temperatures and blade tip speeds inside the turbine are the limiting factors. Therefore, even if the reject heat is used to produce steam that produces electricity in a separate steam turbine and generator, nuclear HTGR will have approximately 500 MW output. Economy of scale begins to work against the plant. This effectively means HTGR can never, ever, be economic.
Next, the system relies on at least one gas-to-gas heat exchanger, which is inherently expensive because gas has a very low heat transfer coefficient. In essence, the exchanger must be huge to transfer the heat required. In addition, the gas-to-gas heat exchanger must be designed to withstand 1000 psi pressure, at relatively high temperature of approximately 1000 deg. F. The high pressure and high temperature also increase the cost. At least two additional helium gas heat exchangers transfer heat against other fluids, presumably cooling water in one instance, and unspecified fluid in the other. These also will have large areas because the gas, as before, has very low heat transfer coefficient. Leakage from tubes must be monitored closely to prevent any material from entering the helium loop.
Next, a reactor vessel rupture or helium piping rupture could send radioactive, hot, balls 2-1/2 inch diameter flying under 1000 psi pressure. Such an event must be considered, designed for, and mitigated as much as possible.
Next, long-term storage of spent fuel pebbles remains a problem.
Next, production of radionuclides from the reactor, transport of those radionuclides into the helium gas circulation loop, and release into the atmosphere in the event of a pipe or system rupture, is a very serious issue.
Finally, the NRC has identified an issue with graphite dust production and transport. This can be an extremely serious issue, as graphite is a form of carbon. Graphite dust is highly flammable and explosive in the proper concentrations.
Previous Experience
A South Africa HTGR reactor was cancelled due to cost overruns, schedule pushed back, and insurmountable technical problems. A project in Germany was also cancelled. Two research reactor projects in the US were also cancelled, one in the early 1970s and the other in the 1980s. The latter plant, at 330 MWe, was likely not merely for research due to the rather impressive size. However, it was shut down due to recurring mechanical problems and what was described as “poor performance.”
The South African experience is described at this link.
Conclusion
The HTGR nuclear reactor system has, as described above, many serious technical challenges that must be overcome. Given the dismal experience in other industries with similar reactors operating at high pressure that attempt to inject a solid into the reactor, it is not surprising that the HTGR reactors also fail. It is true that low-pressure systems can be made to work, but the high-pressure ball injection and removal systems are problematic. The high cost of every component is also a factor. The inherently small electrical output will forever keep the plants from enjoying economy of scale – at least until another advance is made in the gas-turbine and compressor technology. The large size of the heat exchangers adds to the cost, primarily due to the low heat transfer coefficient of the helium gas. This is an immutable characteristic of gas heat exchange, and has been known for many decades. The dismal experience of researchers in several countries over several decades does not bode well for the future of HTGR. The most important issues, though, are the production of explosive graphite dust, and production of lethal radionuclides in the reactor that are transported into the helium circulation loop that includes the heat exchangers, turbine, and compressors.
As with the other new designs, small modular reactors, fusion, and thorium, HTGR is also a very distant pipe dream.
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 One – Nuclear Power Plants Cannot Compete
Part Three – Nuclear Power Plants Cost Far Too Much to Construct
Part Four – Nuclear Power Plants Use Far More Fresh Water
Part Five – Cannot Simply Turn Off a Nuclear Power Plant
Part Six – Nuclear Plants are Huge to Reduce Costs
Part Seven -- All Nuclear Grid Will Sell Less Power
Part Eight – No Benefits from Smaller Modular Nuclear Plants
Part Nine -- Nuclear Plants Require Long Construction Schedules
Part Eleven - Following France in Nuclear Is Not The Way To Go
Part Thirteen - US Nuclear Plants are Heavily Subsidized
Part Fourteen - A Few More Reasons Nuclear Cannot Compete
Part Fifteen - Nuclear Safety Compromised by Bending the Rules
Part Sixteen - Near Misses on Meltdowns Occur Every 3 Weeks
Part Seventeen - Storing Spent Fuel is Hazardous for Short or Long Term
Part Eighteen - Reprocessing Spent Fuel Is Not Safe
Part Fourteen - A Few More Reasons Nuclear Cannot Compete
Part Fifteen - Nuclear Safety Compromised by Bending the Rules
Part Sixteen - Near Misses on Meltdowns Occur Every 3 Weeks
Part Seventeen - Storing Spent Fuel is Hazardous for Short or Long Term
Part Eighteen - Reprocessing Spent Fuel Is Not Safe
Part Nineteen - Nuclear Radiation Injures People and Other Living Things
Part Twenty - Chernobyl Meltdown And Explosion
Part Twenty One - Three Mile Island Unit 2 Meltdown 1979
Part Twenty Two - Fukushima The Disaster That Could Not Happen
Part Twenty Three - San Onofre Shutdown Saga
Part Twenty Four - St Lucie Ominous Tube Wear
Part Twenty Five - Price-Anderson Act Protects Nuclear Plants Too Much
Part Twenty Six - Evacuation Plans Required at Nuclear Plants
Part Twenty Seven - Power From Nuclear Fusion
Part Twenty-Eight - Thorium MSR No Better Than Uranium Process
Part Twenty Nine - this article Part Thirty - Conclusion
Roger E. Sowell, Esq.
Marina del Rey, California
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