Tuesday, October 10, 2017

Post # 111: Resilient Nuclear Power Plants (rNPPs) – Foundational Definitions of Resilience

I briefly discussed the concept of a “resilient Nuclear Power Plant” or “rNPP” in my last post, and offered the following definition:

“Resilient Nuclear Power Plants (rNPPs) are nuclear power plants intentionally designed, sited, and operated in a manner to enhance overall electric Grid and Critical Infrastructure resilience”.

Thus, rNPPs are defined in terms of their impact on and value to the electric Grid – rather than their size, architecture, or the particular technology suite they employ.  rNPPs might be small and modular, or large and monolithic.  The could be cooled by light water, liquid salt, helium, or liquid metal.   They could employ a thermal neutron spectrum or a fast neutron spectrum.  (This is not to ignore the fact that certain combinations of plant and reactor size, system architectures, and technologies might be more enabling in terms of achieving rNPP functionality than other combinations.  These issues will discussed in future posts.)

So, beginning with the end in mind, and working "from the outside - in," let’s first examine the fundamentals of resilience…

Resilient”.  “Resilience”.  What do these words mean?

The Merriam-Webster online dictionary provides the following definitions:


characterized or marked by resilience such as:

a.    capable of withstanding shock without permanent deformation or rupture
b.    tending to recover from or adjust easily to misfortune or change”


1.  the capability of a strained body to recover its size and shape after deformation caused especially by compressive stress

2.  an ability to recover from or adjust easily to misfortune or change.”

But, what do the words “resilient” and “resilience” mean in the context of our nation’s Critical Infrastructure?

The U.S. National Infrastructure Advisory Council’s (NIAC’s) 2009 report on Critical Infrastructure resilience is a great place to begin our examination of this question.  NIAC’s report offered a very helpful, if qualitative, definition of Infrastructure resilience:

Infrastructure resilience is the ability to reduce the magnitude and/or duration of disruptive events. The effectiveness of a resilient infrastructure or enterprise depends upon its ability to anticipate, absorb, adapt to, and/or rapidly recover from a potentially disruptive event.

NIAC’s report continues:

Absorptive capacity is the ability of the system to endure a disruption without significant deviation from normal operating performance. For example, fire-proofing foam increases the capacity of a building system to absorb the shock of a fire.

Adaptive capacity is the ability of the system to adapt to a shock to normal operating conditions. For example, the extra transformers that the U.S. electric power companies keep on store and share increases the ability of the grid to adapt quickly to regional power losses.

Recoverability is the ability of the system to recover quickly – and at low cost – from potentially disruptive events.”

“…For the purpose of this study, critical infrastructure resilience is characterized by three key features:

Robustness: the ability to maintain critical operations and functions in the face of crisis. This can be reflected in physical building and infrastructure design (office buildings, power generation and distribution structures, bridges, dams, levees), or in system redundancy and substitution (transportation, power grid, communications networks).

Resourcefulness: the ability to skillfully prepare for, respond to and manage a crisis or disruption as it unfolds. This includes identifying courses of action, business continuity planning, training, supply chain management, prioritizing actions to control and mitigate damage, and effectively communicating decisions.

Rapid recovery: the ability to return to and/or reconstitute normal operations as quickly and efficiently as possible after a disruption. Components include carefully drafted contingency plans, competent emergency operations, and the means to get the right people and resources to the right place.”

NIAC's report broke new ground and added clarity to the overall issue of Critical Infrastructure resilience.  But what about electric Grid resilience in particular?  How do these general definitions and concepts of Critical Infrastructure resilience apply to the particular Critical Infrastructure sub-Sector that is home to nuclear power plants – the electricity generation and delivery infrastructure, or, more simply, “the Grid”?

I’ll address this question in my next post.

Just Thinking,

Thursday, October 5, 2017

Post # 110: Electric Grid Resilience and resilient Nuclear Power Plants (rNPPs) – An Introduction

The interest in "resilient" critical infrastructure, and electric Grid resilience in particular, seems to be accelerating rapidly.

The National Academies of Sciences, Engineering, and Medicine's recent publication of "Enhancing the Resilience of the Nation's Electricity System," the Trump Administration's focus on electric Grid reliability and resilience (Sec. Perry's Cover Letter and DOE Staff Report on Electricity Markets and Reliability), and this week's Congressional hearings on electric Grid resilience (Resiliency: the Electric Grid's Only Hope) and reliability (Powering America: Defining Reliability in a Transforming Electricity Industry), all suggest the time has finally come for a thoughtful and detailed examination of several closely related topics: Critical Infrastructure resilience, electric Grid resilience and reliability, and nuclear power plant resilience.

I've devoted much of my attention during the past two years to the study of electric Grid resilience and the role (current and future) nuclear power plants might play in enhancing Grid resilience.  During the next few weeks, I'll be sharing highlights here from a 110-page report I published in August [ATI-TR-2017-14, "Resilient Nuclear Power Plants (rNPPs) – Potential Building Blocks of U.S. Electric Grid and Critical Infrastructure Resilience"].  I will also be delivering a paper entitled, "Enhancing Electric Grid and Critical Infrastructure Resilience With Resilient Nuclear Power Plants (rNPPs)," at the upcoming American Nuclear Society Winter Meeting on November 1 in Washington, D. C. 

Resilient Nuclear Power Plants (rNPPs) are nuclear power plants that are intentionally designed, sited, and operated in a manner to enhance overall electric Grid and Critical Infrastructure resilience.

Thus the starting point for discussing rNPPs is the definitions of "Critical Infrastructure resilience" and "electric Grid resilience" – two concepts that are surprisingly difficult to define in a quantitative manner that is useful from the engineering perspective.

I will discuss the concepts of Critical Infrastructure resilience and electric Grid resilience in my next post.

Just Thinking,

Wednesday, September 13, 2017

Post # 109: The future of nuclear power depends on ...

Some of you are probably wondering what happened to Sherrell.  No blog posts since February?  Really?

Without delving into the particulars, I'll just say I've been "head-down" in other pursuits – some of the fruits of which I'll be sharing here over the coming weeks.  Today, I'll simply set the stage...

I'm convinced the future of commercial nuclear power (at least in the western world) hinges on whether the nuclear power industry can improve its "value proposition" to society.

Although every one of the ~ 100 commercial nuclear power reactors built in the U.S. were constructed primarily as a means of providing safe, reliable, cost-competitive BASELOAD electrical generation capacity (and they have generally done so until relatively recently), it is highly unlikely the construction of future commercial nuclear power plants can be justified solely on the traditional baseload generation argument.  That argument is no longer sufficient or compelling.

So... is there a future for nuclear power?  If so, what is it?

I believe there is a compelling argument for more nuclear power; and it has nothing to do with baseload electricity generation, climate change, or industrial heat applications.


I'll delve into these questions in coming posts.

Just Thinking,

Monday, February 6, 2017

Post # 108: Nuclear Power: Black Sky Liability or Black Sky Asset?

After a 33-year career at Oak Ridge National Laboratory, and 5 years in the private sector as an independent consultant, last Fall I re-entered the University of Tennessee in pursuit of my long-delayed PhD.  My research passion lies at the intersection of society’s dependence on electricity, electric Grid vulnerability, and the role of nuclear power in Grid resiliency (particularly with regard to so-called “Black Sky Events”).   

I am pleased to announce my first peer-reviewed publication on the subject was recently published in the International Journal of Nuclear Security.  You may download the paper for free here… 

Here’s the abstract of the paper…

Ready access to abundant electricity is a key enabler of modern life. During the past decade the vulnerability of Critical Infrastructure sectors in the U.S. to a variety of natural hazards and man-made threats has become increasingly apparent. The electrical infrastructure (the “Grid”) is the foundation for all other critical civil infrastructures upon which our society depends. Therefore, protection of the Grid is an energy security, homeland security, and national security issue of highest importance. Geomagnetic disturbances (GMD) induced by solar coronal mass ejections (CMEs), electromagnetic pulse (EMP) attacks, and cyber attacks are three events having the potential to plunge the U.S. into partial or total Grid failure (de-energization) with subsequent blackouts so massive they are referred to as “Black Sky Events”. Embedded in the U.S. Grid are almost one hundred commercial nuclear power reactors in some sixty nuclear power plants (NPPs). This paper explores the nature of society’s coupled “system of systems” (i.e. Grid, other Critical Infrastructure, human operators of these infrastructures, Government, and the Public) that would be stressed by a Black Sky Event, and presents an analytical framework for probing the behavior of this system during Black Sky Events. The question of how NPPs might be impacted by a prolonged Black Sky Event, and what role, if any, NPPs can play in enabling a rapid recovery from a Black Sky Event is examined. The likely behavior of an NPP during a Black Sky Event is discussed, and it is concluded that today’s generation of NPPs are Black Sky liabilities. However, a unique characteristic of NPPs (the large fuel inventory maintained in the reactor) could make the NPPs extraordinarily valuable assets should a Black Sky Event occur. Their value in this regard depends on whether or not it might be possible to affect a number of changes in the NPPs, the U.S. Grid, and other Critical Infrastructure in the U.S. to enable the NPPs to become Black Start Units – generating stations that would be the foundation of recovering the U.S. Grid during a Black Sky Event. This paper poses the question, “Can today’s nuclear power plants be transformed from Black Sky Liabilities to Black Sky Assets, and if so, how?” An integrated framework for addressing this question is proposed.
The paper deals both with the current U.S. commercial nuclear power fleet, and future commercial power reactors large and small.

I hope it is a catalytic contribution to a dialog that needs to occur.



Tuesday, September 20, 2016

Post # 107: Salt Reactors, Kudzu, and Charcoal: The GHG Solution?

Source: Wikipedia, https://upload.wikimedia.org/wikipedia/commons/a/a0/KudzuLeaves.JPG
Source: https://commons.wikimedia.org/wiki/File:Charbon_de_bois_rouge.jpg

Here's an interesting article by fellow blogger Rod Adams over at Atomic Insights, on the possibility of coupling molten salt (or salt cooled) reactor technology with the ancient art of making charcoal, to accomplish the direct removal of carbon from our atmosphere:

Sequestering Carbon Using Mass Quantities Of Small Scale Supertorrefaction Systems

The article discusses the ideas of Frank Shu.

Living in the southeastern U.S., I have to admit my first thought when I saw the article was whether one could "feed" Dr. Shu's liquid salt – charcoal production – carbon capture system with kudzu.  (I'm only halfway joking...)

Several years ago, I led a study at ORNL that looked into the coupling of small nuclear reactors with biorefineries.  Turns out there are a number of challenges.  Some technical.  Some economic.  Some logistical.  Some regulatory.  Many of the technical challenges have to do with inserting thermal energy from a (low temperature) water-cooled nuclear reactor into a highly optimized chemical flowsheet that is based on combustion of some of the biomass feedstock.

One of the logistical issues associated with such enterprises is the effort, energy, and cost required to grow and deliver the biomass feedstock to the reactor site.  Based on these factors, and the market value of the products produced, there's an optimal biomass farm acreage and a maximum distance from the reactor over which the biomass can be transported.

Leads me wonder... what would the economic model for a salt reactor – kudzu control – charcoal factory look like?

Could this be the solution to our carbon and kudzu challenges?

Something to ponder... In the mean time, does anyone know where I can rent a herd of goats for a week or two?

Just Thinking,

Monday, May 11, 2015

Post # 105: My Appointment to DOE's Environmental Management Advisory Board

I was pleased and honored recently to receive a letter from the Secretary of Energy confirming my appointment to the Department of Energy’s Environmental Management Advisory Board (EMAB).  Members of EMAB are appointed by the Secretary of Energy and serve at the discretion of the Assistant Secretary for EM.  My role will be to provide expert advice on environmental stewardship, science, and technology.  My term ends in Sept. 2016.  The mission of EMAB is to provide independent and external advice, information, and recommendations to the Assistant Secretary for Environmental Management (EM) on corporate issues relating to accelerated site clean-up and risk reduction.  These issues include project management and oversight activities; cost/benefit analyses; program performance; human capital development; and contracts and acquisition strategies.  EMAB membership includes individuals from private industry, academia, the scientific community, and governmental and nongovernmental entities.  (You can learn more about EMAB here.)

As I think about this appointment, I recall a conversation I had many years ago with Dr. Alvin Weinberg.  It was a wonderful spring afternoon (much like we’ve been having recently here in East Tennessee), and I had the privilege of sharing the afternoon with him in his home in Oak Ridge.  Just Weinberg and me.  (What a treat!)  I’m sure I asked him dozens of questions that afternoon.  One question I asked went something like this, “What do you consider to be the greatest oversight or worst mistake made by you and your fellow founders of the nuclear age?”  His response was immediate and passionate.  “We underestimated the challenge of dealing with nuclear waste.”  And then almost as quickly he added, “I’m not speaking of the technical challenge.  I think that has been largely solved.  I’m speaking of the challenge of dealing with the public and with the public perception that this is an insurmountable problem.”  Now of course, Dr. Weinberg was speaking primarily about the waste associated with commercial nuclear power.  But I’ve never forgotten that conversation and the larger implications of that conversation with regard both to commercial nuclear power and the legacy waste from our federal nuclear enterprise.

Just a few days ago I had the pleasure of attending the graduation of my niece, Taylor, at the University of Tennessee.  The commencement speaker was Jim Haslam (founder of Pilot Corporation and father of our current Governor Bill Haslam).  As is his style, Jim addressed the graduates and attendees with a brief, focused, and memorable speech.  Among the few points he shared was one that when something like this: “There are three phases in our lives.  Early on, you LEARN – you prepare for your future.  Then, you EARN – you earn you way forward in the world.  Finally, you RETURN – you give back to those who helped you along the way and to society in general.”  I really liked his speech.  Personally however, I like to think that at some point, the learning, earning, and returning become coexistent lifestyle attributes, rather than a strictly serial sequence of life phases.  Learning never stops.  Earning doesn’t end.  Returning is a continuous activity.  (I’ll bet Mr. Haslam really feels that way as well.)

Serving on EMAB is one small way to “return” something to an enterprise that has given me so much over the past thirty-five years.  I look forward to serving.  I encourage you to ask, "How can I serve?" and "How can I return?"  Every one of us has been equipped with gifts, talents, and experiences that qualify us well to serve others.  How about you?  Who are you serving?

Just thinking…


Monday, April 20, 2015

Post # 104: The Sunset of U.S. Nuclear Power?

This is a post I thought I would never write.  It is one I do not enjoy writing. 

I’ve been thinking a lot lately about the future of nuclear power in the U.S.  I’ve concluded those of us in the “pro-nuclear” camp need to face the likelihood that the brightest days for commercial nuclear power in the U.S. are behind us – at least for the balance of this century… that no one reading these words today will live to see the long-awaited “Nuclear Renaissance” in the U.S.  

Put simply, I’ve come to believe the most likely scenario for nuclear power in this country is that it will fail to maintain its current (~ 20%) fraction of the U.S. electricity generation mix for the remainder of the 21st century – and may never return to its current level of market penetration.  I believe this is almost a certainly through mid-century, and highly likely through the remainder of this century.  I hope I'm wrong.

There are a number of potential events (discussed below) that could change my prognosis.  Some of these events might trigger a nuclear renaissance, while others would probably terminate the nuclear power option in the U.S. 

Allow me to layout the facts as I see them, and engage in a bit of not-too-far-fetched speculation.  I actually don’t think it requires much clairvoyance. Reality is staring us in the face.

  • The miracle of fracking has made natural gas “too cheap to meter” – the “Gas Glut”.
  • We have very limited means (i.e. few Liquified Natural Gas [LNG] terminals) to export our abundant natural gas.  So the price of natural gas here is relatively isolated from world market pressures.
  • About half the commercial nuclear power plants in the U.S. operate as “merchant generators” in deregulated markets.
  • Deregulated electricity “markets” place little value on:
    • Supply reliability
    • Supply availability
    • Supply diversity
  • Nuclear power plants in deregulated markets are shutting down because they cannot compete with the price of electricity produced from fracked natural gas.
  • Nuclear power plants only come in “one size fits all” mega-plants.
  • The capital cost of available nuclear power plant designs is obscenely high – untenable absent some revolutionary (to the nuclear power industry) financing strategy.
  • The U.S. nuclear regulatory structure is, in many ways a great success and the standard for the world, BUT it obstructs innovation, ensconces technology lock, and promotes a “good-enough is the enemy of better” mentality throughout the industry.
  • The American public is largely ambivalent about nuclear power.  Spent fuel disposal is a real concern for a vocal minority – but it seems to be the problem that will never go away.

  • Three dozen nuclear plants (1/3 of fleet) shut down within the next 10-15 years (possibly much sooner) because they cannot produce electricity cheaply enough to compete with fracked gas.
  • Perhaps a half-dozen new nuclear power plants are built in the U.S. during the next 20 years.
  • Nuclear’s portion of U.S. generation mix decays monotonically over next 25 years to ~ 13-15% of the U.S. electricity generation mix by 2040.
  • The only “Renaissance” that occurs is a  “Decommissioning Renaissance” (a term coined by my friend Eric Abelquist at ORAU).


The answer to the question of whether or not nuclear power in the U.S. has seen its best days depends critically on what happens between now and 2040 as the U.S. takes a “Nuclear Nap”.

Factors That Might Revive Nuclear Power In The U.S.

I see a few events that might occur in the next couple of decades that would portend a brighter future for nuclear power:

  • A “Fracking Fukushima” occurs – an event (such as the contamination of a major ground water aquifer) that results in much tighter regulation or perhaps even prohibition of natural gas fracking in the North America.  In such a scenario, the price of natural gas would escalate dramatically, making the price of nuclear-generated electricity an attractive alternative again.
  • Orwellian carbon tax is enacted that penalizes natural gas, petroleum and coal – obviously making nuclear power and renewables energy sources more price competitive.
  • A major focus on Domestic LNG Terminal Construction enables the U.S. to export our natural gass, and raises domestic natural gas prices to world market values (a slow effect, no doubt, but one that makes nuclear power more price-competitive).
  • For those of you who are banking on Small Modular Reactors of all sorts – a Revolutionary Reduction in the Capital Acquisition Cost & Operating Cost of nuclear power plants dramatically lowers the barrier to plant acquisition and economic operation.  I’m skeptical about the likelihood of this particular dynamic. Small reactors would reduce the absolute acquisition cost of a nuclear power plant, but barring some other event, I don’t see a revolution coming in the operating cost of nuclear power plants (large or small).  After all, if a fully-amortized large plant operating in today’s deregulated market cannot produce electricity cheaply enough to compete with natural gas, I’m skeptical a new plant – of any size – will be able to reduce the price of electricity production sufficiently to slay the natural gas dragon.
  • Finally, the Emergence of Enlightened Regulated Electricity Markets – markets that place a tangible value on reliability, availability, and diversity of electricity generation sources.  Such markets would seek a strategically-mixed portfolio of electricity generation assets to reduce the overall dependence of electricity production on a single “fuel source”.

Factors That Might Turn Out The Lights On U. S. Nuclear Power

On the other hand, there are a number of potential developments that could drive the last nail in U.S. nuclear power’s coffin:
  • A Breakthrough in Carbon Capture and Storage (CCS) Technology – puts coal back on the table. The U.S. transitions from a “Gas Glut” to a “Coal Glut”.  No one needs nuclear anymore for baseload capacity.  Twenty-five years is a long time for researches to tackle a challenge.  Is there a solution out there for CCS, or will it remain a technology similar to nuclear fusion – always just over the horizon?
  • A Breakthrough in Battery Technology – eliminates the renewable energy (solar and wind) penetration barrier, obliterating the grid instability problem posed by “excessive” penetration of these time- and frequency- varying electricity generators.
  • An American Fukushima-like accident at one of our commercial nuclear power plants – results in the permanent shutdown of the majority of the U.S. nuclear fleet.  (I have previously shared my view that the Japanese people have actually responded to the events at Fukushima in a more sanguine manner than I believe the U.S. population would if such a major accident occurred in the U.S.)

Wild Card Events

There are, of course,  some “Wild Card” events that could happen during the next 25 years.  I'm speaking of events that would throw all the silverware in the air.  Here's my #1 chaos generating event:
  • The mega-event would be a huge Geomagnetic Storm that decimates the North American Grid – forcing a rebuild of both the Generation and the T&D network.  The impact of such an event (which is overdue if history is any guide) is hard to predict.  Solving the nuclear power riddle might be the least of our problems if it were to occur. (Actually, I’d be more concerned about avoiding an American Fukushima if a catastrophic geomagnetic storm occurred.)


One of the (few) benefits of aging is that I’ve become more willing to “stare the dragon in the mouth”.  My analysis leads me to conclude the nuclear industry can put itself out of business by poor safety performance, but it needs a “little help” (probably a “lot of help”) from somewhere else to remain a viable energy alternative in the U.S. through the remainder of this century and beyond. 

We are all notoriously bad at predicting the future.  (After all, who predicted the fracking revolution?)  Whether U.S. nuclear power is sliding into a beauty rest or a coma remains to be seen.  But the next twenty-five years are a crucial time period.  Are we seeing the Sunset on U.S. Nuclear Power, or just a “Nuclear Nap” to be followed by Sunrise on the long-awaited nuclear renaissance?  No one can know.

Just Thinking,