Post # 22: Imperative 4 – Achieving Sustainable Nuclear Fuel Cycles

The fourth Nuclear Energy Imperative has to do with achieving sustainable fuel cycles.

First, let me address my view of the definition of "sustainable".  This actually is not a simple matter.  Many definitions have been offered and there's endless debate about the meaning of this term.  To me, something is sustainable if it does not exhaust fundamental natural resource limits and conveys benefits now and to future generations commensurate with it's costs (economical, environmental, social/cultural).  Sustainability is a benefit/cost issue.  Inter-generational equity is a critical consideration.  Thus, there is also the question of the timeframe over which one performs this assessment.  Is it 100 years, 1000 years, 10,000 years, "forever" ?  From a practical standpoint, given the limits of human knowledge and the progressive nature of science and technology, I tend to adopt the "few hundred years" timeframe for my consideration of such matters.  So let's pick 300 years as the time frame for our analysis.  That's roughly ten human generations.

Second, it's important to have a context for the amount (volume) of spent nuclear fuel currently generated by the nuclear power industry.  As I've noted before, a single 1 Gigawatt electric nuclear power plant produces about 20 metric tons of spent nuclear fuel a year.  That's about forty or so nuclear fuel assemblies for pressurized water reactors.  The entire of inventory of spent nuclear fuel generated in the U.S. today by every commercial nuclear power plant that has every operated can fit in a spent fuel pool less than 300 feet on a side.  (We are NOT generating mountains of spent nuclear fuel in this country.)

My definition of a "sustainable nuclear fuel cycle" is encompassed by five criteria which I term my:

"Five Pillars of a Sustainable Nuclear Fuel Cycle":

1. known uranium resources would support it's deployment for at least 300 years (300 years from above definition of sustainability);
2. it would be "affordable" and economically competitive to nuclear power produces and energy consumers;
3. it would not create unacceptable quantities (volumes) of nuclear waste;
4. the radiotoxicity (health risks) of the spent nuclear fuel and fuel cycle wastes would drop to levels similar to that of uranium in the earth's crust after a relatively short period of time which is meaningful in terms of human social, cultural, and government structures;
5. its deployment would not present unacceptable dangers from the standpoint of nuclear proliferation.

An exhaustive analysis of these issues is well beyond the scope of a blog posting, and much research has been done and is currently underway around the world today.  So just a few comments here...

The amount of uranium "economically" recoverable (Pillar 1) is a matter of some debate and uncertainty.  However, given current projections for world-wide growth in nuclear power, it appears we have or will have access to uranium reserves sufficient for somewhere between 100 and 300 years even if the current once-through open fuel cycle continues to be used.  So, from the resource utilization standpoint, the current once-through fuel cycle isn't sustainable.  Additionally, the current fuel cycle creates wastes (that violate my Pillar 4 above.  So the current open fuel cycle is not sustainable and must eventually be replaced.  However, we clearly have some time to land upon the solution.  (See MIT's recent update of their 2009 fuel cycle study.

So what is my proposed solution?  I believe the "solution" is to develop a nuclear fuel cycle (a suite of reactors, nuclear fuels, and nuclear fuel reprocessing technologies) that achieve my Five Pillars with the added specificity that the time frame for application in Pillar # 4 is 300 years (again ~ 10 generations).  I'm not the only one thinking this way.  Dr. Kathryn Jackson's testimony before the President's Blue Ribbon Commission on America's Nuclear Future this past August promoted a similar view from a leader in the nuclear industry.  Dr. Jackson is Westinghouse Nuclear's Senior Vice President and Technology Officer.

As I said, there's much more here to be discussed.  But for now, let's think about the Five Pillars of a Sustainable Fuel Cycle, and the Five Imperatives of Nuclear Energy as a framework for workable nuclear energy future – here and abroad.

More on the proliferation issue (Imperative 5) soon...

Cheers !

Sherrell

Colossians 1:17

Post # 21: Imperative 3 – Enable the transition away from fossil fuels

Today, approximately 40% of our nation's carbon emissions stem from the use of fossil fuels in the transportation sector (principally liquid fuels production and consumption), and industrial sector (principally fossil-derived process heat production).  Indeed, my own model indicates that even if we completely decarbonized our electricity production, by mid century our total national carbon emissions would drop by less than 25%!

Imagine that!  If not one kilogram of carbon dioxide was released in the production of electricity in 2050, we still would only achieve modest reductions in overall greenhouse gas (GHG) emissions.  Why?  If the population continues to grow at a modest 0.6% per annum, and all these people still drive automobiles, and we still move freight across our country in the same manner, and still provide process heat to our factories in the same manner, we are only addressing 60% of the problem when we focus on electricity production and use.

Improvements in the efficiency of production and use of electricity are already effectively accounted for in my simple analysis.  So, the only way to further improve our lot and achieve more-sizable reductions in our GHG emissions is to transform the transportation and process heat sectors.  We must reduce the consumption of petroleum in our vehicles and the use of oil, coal, and natural gas for production of industrial process heat.

Thus the challenged posed by President Obama's goal of an 80% reduction in carbon dioxide emissions is daunting - to say the least.  In fact, I feel confident in saying the Administration's goals for greenhouse gas emissions reductions are virtually impossible without a revolutionary change in our society.

There are many who believe these energy challenges will drive almost unimaginable changes in population distribution. Interestingly, opposing arguments can be made with regard to the direction of these changes.  Some who have studied this issue believe we will see a massive centralization of our population in urban centers to reduce the transportation costs and petroleum consumption associated with daily commutes to work.  Others feel the opposite will happen – that things will become so dire, our socio-economic infrastructure will collapse, resulting in a return to an agrarian economy.  This belief is normally associated with the assumption there would be a mass exodus from population centers into the suburbs and country side.

There is another solution with five ingredients:

1. Electrification of the private vehicle and over-road freight transportation sectors (probably requires a major breakthrough in battery technology);
2. Switching to synthetic fuels where vehicle electrification is not possible;
3. Switching away from fossil-derived process heat in industrial sectors (especially the petro-chemical sector);
4. Increasing the size of the nuclear electric power plant fleet and improving the electric grid as necessary to deliver the electricity required for # 1; and
5. Developing and deploying a new generation of high-temperature and very-high-temperature nuclear reactors to provide the process heat needed to enable # 2 and #3.

This "simple" formula – electrify the transportation sector and produce the electricity with nuclear power plants, and switch to nuclear-derived process heat across our major industrial sectors – would enable the continuation of life as we know it in the western world.  I am not aware of another strategy that is as practical and easily implemented as this approach.  Frankly, absent this approach, or something very similar to it, things look pretty grim...

Just thinking...

Sherrell

Post # 20: Imperative 2 - Improving the affordability of nuclear energy

The second of the "Five Imperatives of Nuclear Energy" is: we must improve the affordability of nuclear energy and nuclear power plants.  I'll discuss that today...

Once the construction cost of a nuclear power plant is fully amortized (ie., the "construction loan" for the plant is paid-off), nuclear power plants produce extremely cheap electricity.  The typical cost of electricity production in today's nuclear fleet is less that 3 cents per kilowatt-hr of electricity produced.  In my part of the country (TVA service area), residential electricity sells for about 8 cents per kilowatt-hr – cheap by national standards.  Since most plants are "paid-off" within twenty years, nuclear power plants that are more than about 20 years old are tremendous revenue producers for their owners (you and me if we happen to own stock in a company who owns and operates such a plant), and a source of very affordable electricity for their customers (again... you and me).

While the details of the affordability issue can be complex, at a high-level these issues reduce to three primary factors that have driven the purchase cost of modern nuclear power plants out of the "affordable" range for many prospective buyers:

1. Todays plants are large (typically greater than 1 GWe in size).  Due to "economy of scale" considerations, the nuclear industry evolved to a "one size fits all" mentality in which the one size was a hugh plant.  Too bad if you really didn't need all of that electricity production capability in one incremental addition.
2. Like all large, complex facilities,  these large plants require vast quantities of steel, concrete, wire, and other construction materials, along with extensive labor to design and build the plants.  Capital cost estimates for current large plant models range from around $4000 per kWe to as high as $8000 per kWe for a complete plant that is fully-integrated into the utility's electric grid.  That's $4-8 BILLION dollars for a single nuclear power plant. Not something you're apt to find in Walmart!
3. The time period required to build, license, and commission our most recent nuclear plants (7-10 years) resulted in high finance charges for the capital the utilities had to borrowed to purchase the plants.  This protracted time period was in large-part the artifact of an inefficient licensing process that, in practice, made it extremely difficult to predict when a plant would be allowed to start operations and how much finance charges the owner would have to pay in the interim.  Neither financiers or owners liked that situation.

The solutions to these challenges ?

1. One of the most exciting developments in this regard is the mushrooming interest in small modular reactors (SMRs).  These plants, ranging in size from as little as 10 MWe to around 300 MWe, would significantly reduce the "single purchase" cost of plant due simply to their small size.  Additionally, many of these plants have features that should enable more automated fabrication and construction, offering the potential to reap the benefits of high-volume "factory fabrication"and simplified field installation.
2. During the past several years, the U.S. Nuclear Regulatory Commission has reformed and modified it's design certification and plant licensing process.  While maintaining a sharp focus on assuring the safety of new plants, the reformed process should provide a more predictable and accelerated licensing process compared to that experienced in the last several plants built in the U.S.  twenty-some years ago.

While there are a number of other relevant factors and dynamics in play, the advent of small nuclear power plant options, and (hopefully) a more reliable licensing process, should go a long way toward achieving Imperative 2.

Next time, Imperative 3.

Cheers,

Sherrell,  Col 1:17

Post # 19: Imperative 1: The Anchor of a Sustainable Energy Future

In Post #18, I introduced the concept of the Five Imperatives of Nuclear Energy.  Briefly, these Five Imperatives are:

1. Extend the life, improve the performance, and sustain the health and safety of the current commercial nuclear power fleet;
2. Improve the affordability of nuclear energy;
3. Enable the transition away from fossil fuels in the transportation and industrial sectors;
4. Achieve sustainable nuclear fuel cycles;
5. Assure the deployment of nuclear power systems does not result in the proliferation of nuclear weapons.

Today I will briefly discuss Imperative 1.

Every year since 2005, the U.S. commercial nuclear fleet of 104 operating reactors has produced approximately 4 billion megawatt hours of ultra-low-carbon electricity .  This is 70% of our nation's low-carbon electricity.  According to statistics from the Nuclear Energy Institute, the U.S. nuclear fleet provided this energy while enabling us to avoid the annual production and release of ~ 52 million short tons of sulfur dioxide, 20 million short tons of nitrogen oxides, and 647 million metric tons of carbon dioxide that would have been released into the environment had the same amount of electricity been produced by fossil-fueled power plants in the regions where the plants operate.  In exchange for the electricity produced, the fleet produced approximately 2200 metric tons of used nuclear fuel.  This amounts to around 4400 fuel assemblies, each 12-14 feet long and about 8 inches square - not a large volume of "waste" for the tremendous amount of low-carbon electricity provided.  It would all fit into a box 15 feet high by 67 feet on a side if stored as we store used fuel today.

Every credible low-carbon energy scenario I have seen depends on and is anchored by the assumption our current nuclear fleet continues to operate well past the original 40 yr. license period of the reactors.  I'm convinced significant reductions in our carbon emissions rates are impossible unless we maintain the health and extend the operational lifetimes of these workhorses of clean energy, and supplement them with as much wind and solar energy we can produce.

Thankfully,  at this point, 59 of the 104 operating U.S. nuclear power plants have been grated 20-year license extensions, 20 additional units have filed applications for a license extension, and  19 additional units have indicated they will file for a license extension (total = 98 units).  

The next question is, "how long can these plants continue to safely operate?"  The U.S. Department of Energy's Office of Nuclear Energy, the U.S. Nuclear Regulatory Commission, and the Industry are currently partnered in an R&D program called, the "Light Water Reactor Sustainability (LWRS) Program, which has among its goals the development of the science-based understanding of plant aging required to answer this question.  In addition, DOE recently awarded its Nuclear Energy Modeling and Simulation Innovation Hub to the Consortia for Advanced Simulation of LWRs (or "CASL") –  a team led by Oak Ridge National Laboratory.  CASL has among its goals the development of a "virtual reactor" as a tool for exploration of many reactor performance and aging phenomena.

So... it's a good news story... Our commercial nuclear fleet currently operates at over 90% average availability, with a stellar safety record.  It's the anchor of any realistic low-carbon energy production future.  The fleet's operating life is being extended from the original 40 years to 60 years, and intensive research is underway to allow us to maximize  the safe operating lifetimes of the low-carbon work horses.

We'll discuss the other Imperatives in future posts.

Cheers,

Sherrell

Colossians 1:17

Post # 18: The Five Imperatives of Nuclear Energy

This past week I was on the road.  I attended the American Nuclear Society Annual Meeting in San Diego where I presented a paper entitled, "Fluoride Salt High Temperature Reactors (FHRs) and the Five Imperatives of Nuclear Energy".   The Imperatives are the five nuclear energy objectives I believe the U.S. must achieve in order to secure a sustainable energy future for our country.  The Five Imperatives are:

1. Extend the life, improve the performance, and sustain the health and safety of the current commercial nuclear power fleet;
2. Improve the affordability of nuclear energy;
3. Enable the transition away from fossil fuels in the transportation and industrial sectors;
4. Achieve sustainable nuclear fuel cycles;
5. Assure the deployment of nuclear power systems does not result in the proliferation of nuclear weapons.

These Five Imperatives are an integrated framework of outcomes that will assure a long-term supply of safe, secure, affordable, environmentally sustainable nuclear energy for generations to come.  I'll be discussing each of these Five Imperatives in more detail here in future posts.

Cheers,
Sherrell
Colossians 1:17

Post # 17: The Gulf Oil Leak – A Tragedy In Slow Motion

Like virtually everyone else, I've been watching the unfolding tragedy in the Gulf of Mexico with a growing sense of doom and sickness in my stomach.  The oil has continued to spew at an alarming rate from the twisted remains of the Deepwater Horizon oil rig since the day of the explosion.  It's like watching a tornado destroy you home in super-slow motion.  And it continues.

The cost of the oil rig disaster in human lives (11 prompt fatalities) is terrible.  The ecological cost to our gulf cost is yet to be bounded, grows by the day, and will probably linger beyond my lifetime.  The economic impact on millions of Americans who draw their living from the sea and the vacation industry will likely be profound.

Why did this have to be the case - given the leak occurred ?

There are many avenues of pursuit to address this question, but the one I've been pondering during the past several days has to do with a simple technical reality: if the oil leak where in 200 feet of water, rather than 5000 feet of water, the leak might have been stopped by now.

Access is a prerequisite for remediation.  It would be nice if we could put human divers down there to work the problem.  I'm not a diver, but I understand commercial divers, using the best available equipment, can reach depths of less than 2000 feet and then only for very limited times.  More routine commercial diving is done in waters of less than 300 feet in depth.

It's a given that if one is in the oil drilling business, one must drill where the oil is to be found.  This said, drilling in shallow water is safer than drilling in deep water.  Easier access if things go wrong.  Oil drilling on land is safer still.  Even easier access.  (This does not account for the varying degress of sensitively of the natural environments surrounding drilling operations.)

But most vacationeers who pay a hefty sum for their ocean-front condos are not inclined to favor those places in which the views are dominated by oil rigs.  In this respect, oil rigs share some of the same "vista challenge" issues as wind turbines.

So we can drill in deep water.  Out of sight, out of mind.  And when something goes wrong, it may be devilishly-difficult to correct.  Or we can drill in shallow water.  Fouls our view of that golden sunset, but we can probably fix a problem in 200-300 feet of water.  Or we can drill on land.  Access not an issue,  but many of the remaining desirable drilling sights are in sensitive environmental areas.

As a personal note here, I've always been very circumspect about off-shore oil drilling due to my concerns that something like the Deepwater Horizon disaster might happen.  And I've never embraced drilling in the Arctic National Wildlife Refuge or similar sensitive ecosystems.

Just one more illustration of the complexity of our energy challenges and the difficult choices we must make to tackle them.

Cheers,
Sherrell

Post # 16: The Price of Our Addiction To Fossil Fuel

I was listening again tonight to the latest news from the Gulf Coast regarding the evolving consequences of the April 22 explosion at  the Deepwater Horizon oil rig.  The news reminded me of the price we pay for our "addiction" to oil.  While the potential environmental consequences are alarming, it is the human cost that attracted my attention.


Eleven workers were killed in the Deepwater Horizon accident.  The Deepwater Horizon explosion is the deadliest U.S. offshore drilling rig explosion since 1968, when 11 died and 20 where injured in an explosion on a rig owned by Gulf Oil.  The Deepwater Horizon tragedy follows on the heels of a March 2005 explosion in BP's Texas City refinery, when 15 were killed and hundreds were injured.


Then I thought of the tragic loss of 29 coal miners in early April in the Upper Big Branch coal mine explosion in West Virginia.  The Sago mining disaster in 2006 killed twelve miners.  The U.S. coal mining industry reported it's lowest fatality count in history in 2009 when 12 fatalities occurred.  (Historically, China apparently has suffered around 5000 coal mining fatalities every year.)


The extraction and use of fossil fuels is a dirty, dangerous business.


I consulted several sources in an attempt to uncover the mining fatality statistics for uranium mining.  All the sources I consulted acknowledged that uranium mining is much safer than coal mining, but I did not uncover hard statistics of the direct fatalities resulting from the uranium mining enterprise.  I will continue to seek hard data (I'm sure it's available - just couldn't find it conveniently tonight) and I will update this posting when I uncover meaningful data.


I did uncover an interesting (and somewhat controversial) article from the Next Big Thing website (http://nextbigfuture.com/2008/03/deaths-per-twh-for-all-energy-sources.html).  The article presents an analysis of the integrated "life-cycle" fatality rate per TWh of electricity generated from nuclear, coal, wind, and solar energy sources.   (I caution that credible analyses of this type of are devilishly difficult to perform.)   This analysis utilized a variety of data sources and it's methodology is not completely transparent.   So, while I cannot validate or endorse this analysis as authoritative, the results do provide interesting fodder for energy-geek party conversation:


Coal: 163 fatalities per TWh
Rooftop Solar:  0.44-0.83 fatalities per TWh
Wind:  0.15 fatalities per TWh
Hydro: 0.1 fatalities per TWh
Nuclear: 0.04 fatalities per TWh


I'll continue my search for more detailed analyses...


The bottom line?


1.  We pay a high cost in human loss and suffering from our addiction to fossil fuels.
2.  There is no zero-risk energy production technology.  No free lunch.
3.  Energy generation from renewable sources is far superior to that from fossil energy sources.
4.  Nuclear energy is among the most human-friendly, if not the most human-friendly energy production option.


Nuclear energy: a sustainable energy option.