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  

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


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)




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. 

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.    

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. 

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. 

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.   

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. 

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?

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.” 

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.

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. 

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. 


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



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 Nine - this article 

Part Thirty - Conclusion

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