Tuesday, July 20, 2010

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.


Sherrell,  Col 1:17

Wednesday, July 7, 2010

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.

Colossians 1:17