Saturday, April 29, 2017

Comparing Energy Technologies:

The Many Shades of Green

I am pleased to report that I recently had an article published in Physics World called "How Green is Nuclear Energy?"  I developed this article in response to their request, and it was published as the lead article in their special issue, "Focus on Nuclear Energy."

The online version of the article at the link above attracted a number of interesting comments.  Several of the comments addressed areas that I hadn't covered in the article.  These were valid criticisms, but I was dealing with a strict word limit, and as I have observed many times, energy is a very complex area.  Any analysis of energy alternatives must address multiple dimensions, including economics, health and safety, environmental impacts, resource availability, and reliability.  And each of these areas has multiple dimensions as well.  For example, environmental considerations include impacts on air, water, and land.  To say nothing of the fact that some elements of the picture change over time--new technology developments, new resource discoveries, changing international political alliances, and other factors all affect the comparison of different energy supply alternatives.

So, when I undertook this assignment, the editor and I agreed that I should focus a lot on greenhouse gases (GHGs), since that is a major concern around the world today.  The editor also wanted me to address the issue of waste, as that is an issue that is often regarded as the Achilles heel for nuclear power. 

Even covering those areas proved quite a challenge, and in the end, I would characterize what I wrote as an overview of the topic.  I tried to mention other elements that could affect the comparison of energy technologies, but did not have the space to explain them.

Thus, some of the comments picked up on areas that I had only mentioned in passing.  For example, one comment noted that the impact of nuclear accidents on the environment might trump the benefits of nuclear energy.  This topic alone is a huge one, and to address it properly, one would have to compare region impacts versus global ones, short-term impacts versus long-term ones, the costs and potential for cleaning up from accidents versus dealing with climate change, and much more.  And, while the impacts of an event at a solar or wind farm may be small, one should then consider the whole life cycle of other technologies.  To cite just one recent example that crossed my desk, solar panels and wind farms use materials that are, to date, in limited supply.  However, some people believe that there are large untapped resources at the bottom of the sea--but mining materials for solar panels in the oceans can carry risks to the environment in case of accident that could be widespread and significant.

Other comments legitimately noted areas that I hadn't addressed.  One commenter, for example, spoke to the fact that we should reduce our use of energy.  I agree that conservation should be part of the equation (although the author of the comment may have had more in mind than the type of conservation I am thinking about), but trying to evaluate how much we could save was beyond my mandate.  Furthermore, globally, there are huge numbers of people who live in severe energy poverty, so the calculus of how much energy the world really "needs" quickly becomes very complicated.  My focus was limited to addressing nuclear power as one option to meet whatever energy needs society has, and to assessing nuclear power in terms of its effects on the environment, i.e., it's "greenness."

Another commenter observed that we may not really know how good or bad different pollutants are.  Can increased levels of CO2 be a good thing?  Can radioactivity lead to mostly good genetic changes?  And the author of that comment wonders if mankind will even be around forever, so what difference does it make?  Again, my mandate stopped far short of such apocalyptic musings.  The author of that comment does make a good point that perhaps there may be ways to recycle CO2 and use it, and indeed, there are researchers looking at just such things.  But, unless you feel that the fate of mankind is already determined and there is nothing we can do, I feel that our role is to plan the best we can for the world as we know it.  It is a delicate balance, I know.  You can't totally ignore the fact that we are working on improved ways to store energy, cheaper and more efficient solar cells, advanced nuclear reactors, nuclear fusion, etc.  I do not doubt that, 100 years from now, the conversation about the greenness of one source of energy or another might be very different.  But today, we can only operate on the best knowledge we have, and my comparisons are made in that spirit.

Finally, one commenter noted that I hadn't covered all the materials issues associated with power production.  In particular, that author mentioned the large amount of cement needed for nuclear power plants.  This one was of particular interest to me, because I have seen a lot of discussion of the materials requirements for different energy sources, and while current nuclear power plants are large structures and clearly require a lot of cement, most sources I've read point to wind and solar energy as the major culprits for large use of construction materials.  While a single windmill is, of course, much smaller than a nuclear power plant, the diffuse nature of the wind and sun creates a requirement for many windmills or solar panel structures, and the resulting use of materials is much higher, per unit of energy generated, for solar and wind plants than for nuclear plants.  One example of the comparisons I have seen is provided in a table by Breakthrough, that is based on data from a report by the University of Sydney, in Australia. 

My one brief article was not intended to address all the issues.  Nor was it intended to "prove" that nuclear power is the best of all options.  As I said in the article, there are clearly shades of green.  And there are shades of any other element of energy production we may care to examine.  The whole point of my writing the article is that we need to move away from the simplistic views of energy technology that regard wind and solar as green because it is natural, and everything else as bad.  Wind and solar power do have impacts on the environment, and a fair comparison of energy technologies has to look at multiple dimensions.  Each will excel in some areas and fall short in others, and finding the right balance is, and will remain, a difficult and imperfect process.

Update May 5, 2017:  The graph below, from a Department of Energy report (Table 10.4, DOE Quadrennial Technology Review 2015), came to my attention after I posted this article.  I add it here as a further example of the materials requirements for different energy technologies:


Sunday, April 2, 2017

Westinghouse Bankruptcy:

What Happened?

In the wake of the announcement this past week that Westinghouse filed for Chapter 11 Bankruptcy as a result of the losses incurred in the construction of four AP1000 units in Georgia and South Carolina, everyone is trying to figure out what happened.

Westinghouse, after all, certainly has long and extensive experience in the nuclear power design and construction business.  They have been in the nuclear business since the 1950s, and were responsible for the Shippingport reactor, one of the first commercial power reactors in the world.  The Westinghouse website states that, "Our technology is the basis for nearly 50 percent of the world's operating commercial nuclear power plants." 

And, after all, NRC had put in place a rule, Part 52, that was designed to make the licensing process more efficient and predictable than the old process (Part 50) had been.

So, what could have gone wrong?

In just the few days since the announcement, I have read several analyses that come to very different conclusions about the cause of the bankruptcy.  I am still sorting out all the views, but in the meantime, I thought it might be helpful to start tracking the various opinions and thinking about them.  I thought some of what I have been finding might be useful to share.

Regulatory requirement 

One of the first analyses I read, by Rod Adams, focuses on regulatory requirements that were imposed on these four units at a late stage in their design.  In particular, he points to changes in 2009 in NRC's requirements regarding aircraft impacts.  He notes that the NRC exempted current plants, and plants for which a construction license had already been granted.  Although the Summer and Vogtle units did not yet have construction permits and the detailed design was not yet complete, the design as it existed at that point had been sufficient to serve as the basis for a cost estimate and a firm price.  The subsequent redesign effort led to delays and resulted in a significant impact on the facility structure.  

Business decision

Another early analysis, by Jim Conca, attributes Westinghouse's problems to bad business decisions.  Conca points out that Westinghouse chose the Shaw Group to manage the construction of the four units at the two sites.  Shaw had no direct experience building nuclear power plants, but it had bought Stone and Webster out of bankruptcy.  Stone and Webster was an old nuclear company and had been responsible for building a number of nuclear power plants between the 1950s and the 1970s.  This gave Shaw the credibility to win the contract.  However, Stone and Webster no longer had any real nuclear expertise or staff, and the project experience significant delays and cost overruns.  Conca details further transactions, including to Chicago Bridge and Iron, which was a large engineering firm, but also had no nuclear experience.

Erosion of Expertise

Still another view is espoused by Paul Dickman, who previously worked at the NRC.  He points to the loss of the skilled workforce.  Of interest, he attributes lack of experience as a factor on all sides, not only on the construction side.

Scale of Project

One argument I haven't seen offered yet for the particular case of the Westinghouse bankruptcy, but that I have seen mentioned before for large-scale projects like nuclear power plants is the fact that many, if not most, large-scale projects seem prone to significant cost overruns.  Much has been made about this in the case of recent projects to build facilities for the Olympics, but many of the articles on the cost overruns for the Olympic facilities also mention other "megaprojects," such as bridges, highways, railways, and power stations.

All of the above?

My own guess is that several of these factors, perhaps even all of them, may be contributing elements.  For any one element, perhaps one could argue that Westinghouse should have anticipated some problems and built in some margin in its estimates or incorporated some flexibility in their contracts, but perhaps the combination of all these factors was a "perfect storm." 

The only thing we can be sure of at the moment is that there is likely to be a lot more evaluation of all the circumstances leading up to this bankruptcy, and a lot more guessing about what Westinghouse should have done.  Or, perhaps of more relevance, about what vendors should do in the future.