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.




  1. I like your list of recommendations, but I think you missed a big one that really should be numbered 0:

    0.  Add redundant small steam turbines to existing NPPs to provide on-site power for all reactor circulating pumps, steam generator feed pumps, and condenser water supply pumps independent of offsite power.  These turbines should share shafts with alternators which are synced to the grid (so can be powered by the grid in the absence of steam, e.g. startup from cold) but allow operation of all reactor systems without diesel generators despite LOOP and shutdown of the main turbine and alternator.

    This would be a much smaller undertaking than designing and building megawatt-class bootstrap reactors.  Guaranteed supply of feedwater and condenser cooling water would allow a rampdown from 100% to perhaps as low as a few percent of full output instead of a SCRAM.  This level of output could be sustained for many years if necessary.  If shutdown was still necessary after a failure to restore the grid, the level of decay heat would be greatly reduced due to the vastly lower inventory of short-lived fission products.  1% of 170 MW(t) is a great deal smaller than 1% of 3.4 GW(t).

    If the decay heat can be ramped down sufficiently by low-power operation, the reactor might be able to cool itself by natural air circulation after a few days of diesel-powered cooling and become walk-away safe even in the worst-case scenario.

  2. There is also such a thing as a tubo-kinetic turbine generator that runs on low pressure steam and water, and is self pumping. This requires no electricity to start or operate. The turbine is operating now, I am looking at integrating it as into nuclear plants. Also, using the same technology to do basic cooling water, condensate, and some feedwater pressure using waste plant heat to keep turbines online with no electrical power. This can be done today.

  3. Why do folks have an addiction to cute terms, like "black sky event"?

    Just say it in plain English: "widespread power-system failure", whether due to Nature (a Carrington Event), the Russians, or just our tradition of communications-network stupidity.

    A properly-designed nuclear plant should have no problem with Black Swan, Black Sky or even Blackbeard events, because: a) it'll not be on The Internet, b) it'll have proper transmission corridor protection, c) proper physical protection, and d) proper backup systems, etc. Our Diablo Canyon plant is a good example.

    Plus, a fission plant is a storage system, and needs no new fuel for long intervals -- a property often exploited by our CAISO when other power sources are, or will be, inadequate.