Tuesday, January 22, 2019

Nuclear-Powered Aircraft:

Visions from the Past

I was surprised yesterday to see in one of my emails an article published on January 20 in The Atlantic entitled "Why There Are No Nuclear Airplanes."  I have some personal history related to the concept of nuclear-powered aircraft, so this brought back some memories.

As it turns out, the concept of a nuclear-powered aircraft has been considered at least twice.  This article recounted the first efforts to develop nuclear powered aircraft, starting in the late 1940s and continuing through the 1950s.  This was by far the larger effort, and certainly the one that should receive the most attention. 

However, there was a second effort in the 1970s that was much more limited and is much less known than the first initiative.  The Atlantic article didn't cover the second wave at all.  Although the second effort was shorter lived and never got beyond the very early planning stage, I thought it might be worth completing the picture by describing that effort.

But first, to recap the original program.  As The Atlantic article indicates, the 1950s concept for a nuclear-powered aircraft focused on supersonic aircraft that could stay aloft for long periods and wouldn't need refueling.  The payload capacities of the aircraft at that time, however, posed a number of limitations.  On the plus side, they led to the early R&D efforts on molten salt reactors, which had the ability to achieve a high power density.  However, even with the high power density, the plane could not carry the additional weight of a fully shielded reactor.  Therefore, the concept involved an unshielded reactor, and the pilots would have been subjected to high levels of radiation exposure. 

The program was ultimately cancelled in the early 1960s.  By that time, the development of ballistic missiles, mid-air refueling, and longer range jet-fueled bombers largely filled the niche that nuclear-powered bombers would have filled. 

Fast forward another decade or so.  With my freshly minted doctorate in nuclear engineering, I ended up working for Analytic Services Inc. (ANSER), a company that worked mainly for the Air Force.  When I was hired, I was told that I'd work on a variety of issues, but I would be the source of expertise within the company whenever a nuclear-oriented project came up.  Although that sounded intriguing, I wondered at the time if I'd ever see such a project. 

I didn't have long to wait.  Shortly after I arrived there, ANSER was asked by the Air Force to do a study on a concept for a nuclear-powered aircraft.  This concept was much different than the earlier effort.  The need now was considered to be for an aircraft that could stay aloft for long periods of time for purposes such as command and control.  Thus, it would only need to operate at subsonic speeds.  It would also take advantage of the latest in both aircraft and nuclear reactor technology.  And the concept I was to analyze definitely called for the reactor to be shielded. 

Well, that analysis showed that even with the larger aircraft that would be used, the weight of a shielded reactor would leave no allowance for any payload.  That alone doomed the concept in this second round.  (And there was no longer any consideration of exposing flight crews to an unshielded reactor.)  In addition, this was the period where public concerns about the safety of nuclear power plants were beginning to emerge, and the anticipated public resistance to the idea of flying reactors over the country also dampened the enthusiasm for this project.  

So this time, the effort was limited to a paper study and to briefings and discussions with representatives from key Air Force and other organizations that would be likely to participate in such a project if it were to move forward.  No funding was ever allocated, and no R&D was ever initiated.  Thus, it is only a footnote in history.  Nevertheless, it is of interest to those who follow the history of nuclear power, and it is a reminder of how some concepts can be revived in different guises as technology develops and needs evolve.

At the time I did this work, much of it was classified, but when I tried to see if anything was now publicly available, I came across this very comprehensive study, which I can recommend to anyone who wishes to learn more about the brief renewed attempt to develop a nuclear-powered aircraft.


Tuesday, January 15, 2019

Nuclear Power and Molasses:

Anniversary of a Lethal Molasses Spill

I was reminded this morning that today is the 100th anniversary of a lethal accident in Boston involving--yes, molasses.  The Great Molasses Flood of 1919 may sound quaint and silly today, but was, in its time, a significant accident that triggered changes in construction requirements and laws requiring professional certification of engineers. 

This sad anniversary reminded me yet again of how rules and regulations, onerous as they may seem, often trace their origins to the tragedies that occurred in the days before society realized the dangers of some of its activities.  I have written previously about the Triangle Shirtwaist Factory Fire of 1911 and the ensuing developments in fire codes. 

And both of these historic events, as well as others, always make me reflect on how we can anticipate the potential for accidents as we develop and deploy new technologies and put the right preventive measures in place before anything happens, rather than after. 

It seems to be an issue that arises in every area of human endeavor.  After all, who would have imagined that molasses might cause such a deadly accident? 

Today, we face other technological developments that raise similar questions:  What are the potential risks from driverless cars?  How can we assure that GMOs are safe?  Is fracking a miracle development to extract more fossil fuels from the earth, or are we going to trigger earthquakes?

The nuclear power industry has long grappled with such questions in relation to the use of the atom, and some of the techniques developed to analyze different nuclear accident scenarios, such as probabilistic risk assessment, have been adopted by other industries as well. 

That is not to say that the nuclear field has all the answers.  Indeed, the issue of risk from technologies seems to be a continually evolving one.  Population growth in an area, rises in sea level, changes in weather patterns, competing societal requirements, and more all affect the calculation of risk from nuclear power, as well as from other technologies.

And the answers are never simple and never perfect.  Some answers require costly systems to prevent or mitigate accidents, or siting restrictions, or other constraints.  And we continually seem to discover new issues, or new aspects of issues we thought we understood. 

These are not issues that can be resolved in a blog.  But the fact that this is the anniversary of an event that sparked a lot of change in its time does deserve mention in a blog on nuclear power issues.  At a minimum, it reminds us that society has dealt with the issues created by "new" technologies (or, perhaps in the case of molasses, a growing industry) for a long time, and it gives me hope that we will continue to do so with the technologies of today.


Thursday, December 20, 2018

N.S. Savannah:

The Final Phase

One of the early chapters in the history of nuclear power is about to enter its final phase.  The N.S. Savannah, which was built as part of the Atoms for Peace program started by President Eisenhower to demonstrate peaceful uses of atomic energy, became the first nuclear-powered civilian cargo/passenger ship when it was put into operation in 1962.  It is currently being readied for decontamination and final disposition.

The ship was operated until 1971, and the fuel rods were removed from the reactor core a few years later.  It has been maintained in that state, and in recent years, has been berthed in Baltimore Harbor awaiting a final determination of its fate.  The US Maritime Administration (MARAD) has maintained it, and over time, has even restored portions of the public areas of the ship.  However, this has always been regarded as a temporary state.

Now, MARAD has begun the process of decontamination of the ship as a step towards its eventual disposition.  The most exciting aspect of this process is that part of the containment has been cut away.  This will enable the removal of asbestos and and the reactor core.  In the meantime, the opening of the containment allows this rare panoramic view of the inside of a reactor containment:

The decontamination process is triggered by the fact that the ship still holds a license from the U.S. Nuclear Regulatory Commission.  That license expires in 2031, and by law, decommissioning should be completed before the license expires.  Decontamination is the first step in the decommissioning process, and expected to take several months. 

For those who are interested, there is a great virtual tour that takes you to a number of locations on the ship, including around the outside of the containment (before the containment was opened).  The website also has more information on the history of the ship. 

In the meantime, the ultimate disposition of the ship is still under consideration.  MARAD and a number of other interested organizations are actively discussing the next steps.  Possibilities range from preservation of the entire ship to scrapping the hull and preserving only a few key components at a museum or other facility.  Obviously, everyone is hoping the ship can be saved intact, but that depends on it finding a suitable home.  I would be happy to pass on any offers to host this historic ship!


Saturday, November 3, 2018

A Visit to Fukushima:

The Site Today


[Note:  Paragraph 5, on observable impacts to the area outside the plant, and paragraph 8, on observations at the site, were modified on November 9 to add a couple of additional observations.]

I recently had an opportunity to visit the Fukushima Daiichi Nuclear Power Station for the first time.  While many people have visited the site since the accident on March 11, 2011, the site does keep changing, so I thought my observations might be of interest.

I was in Sendai, Japan to participate in the International Conference on Maintenance Science and Technology (ICMST), and on the day following the conference, they offered a bus trip to the plant and a tour of the site.  A group of about 3 dozen of us boarded the bus at 8 am at the Sendai train station for a tour that would take us first to the Naraha Center for Remote Control Technology Development, run by the Japan Atomic Energy Agency (JAEA), and then to the Tokyo Electric Power Company (TEPCO) Fukushima Daiichi site.

The Naraha site, about 2-1/2 hours south of Sendai (past Fukushima), was established following the Fukushima accident, is intended to provide a center for organizations engaged in nuclear power plant decommissioning activities to develop and test robotics and other equipment and procedures for decommissioning.  We visited the 2 main facilities--a full-scale mock-up test area, and a virtual reality system.  The virtual reality demonstration was particularly dramatic, as we "toured" the inside of the power plant.

We then turned north again and traveled to the Fukushima plant.  As we got close, my first reaction was that nothing seemed wrong in the surrounding area.  There was other traffic going in both directions on the route we were traveling.  There were stoplights on the road we were on.  We were passing houses and shops.  All of them seemed intact.  They were not boarded up, there were no signs of vandalism, and there were cars parked in front of the buildings.

It was only when we looked closely that we started seeing that something was not quite right.  There were no people around any of the shops.  Some of the side streets were blocked off, or had policemen controlling access.  In fact, entrances to parking areas were also blocked, so you could drive through the area, but not stop here.  As we really focused on what we were passing, we could see places where the grass and bushes and trees were clearly taking over, covering paved areas and entries to buildings.  Once we had figured out what to look for, it became obvious that we were driving through a no-man's land.  And to drive the fact home, from time to time, there were displays on the side of the road broadcasting current readings from local radiation monitors.   

When we got to the nuclear power station, we were taken first to a building where we had a briefing on what we were about to see, and then to another building to prepare for our tour.  While I've seen and heard reports of groups that have toured some areas by foot, we were going to stay on a bus and tour strictly by bus.  That was a disappointment, but it undoubtedly saved a lot of time, as we didn't have to don much protective gear.  It seemed to take long enough as it is for all of us to be issued entry cards, dosimeters and cotton gloves, and to be processed in.  And, unfortunately, we had to leave all cameras and cell phones behind, so I have no personal photos of this visit.

Once into the facility, we boarded another bus and went on a very thorough tour of the facility from the roads.  We passed all 6 units, and probably got within 50 yards of several of the damaged units, with frequent stops for the guide to explain what had happened at each unit, and what has been done since then.  In Unit 1, we still could see the skeletal remains of the building, while Unit 3 has been covered with a dome for the refueling operation.  Where damage is still visible from the vantage point of the bus, they pointed that out.  As we drove around the facility, they also indicated where the ice wall was, and the pipes that feed it.  One impressive feature is the hundreds of tanks that have been brought in to allow the storage of contaminated water.

They also showed us some of the human side of the facility, both before and after the accident--the remaining cherry trees of the hundreds that used to line the main drive and that were enjoyed by the staff in the spring (many had to be sacrificed for some of the post-accident activities), the new administration building, the housing for staff.  Also obvious were cars without license plates sitting in the parking lot; they had been on the site at the time of the accident and are now limited to use on the site.  They were particularly proud of some of the progress they've made.  In 96% of the facility, decontamination has reduced contamination to low enough levels that no protective clothing or only light protective clothing is needed.  (Of course, some of the more intense work is in the areas that are still contaminated, so a significant percentage of the staff still needs to suit up.

In the briefings and on the tour, there was much emphasis on the fact that they are only 7 years into an activity that is expected to last for decades.  It will be interesting to continue to follow this activity and track the progress over time, although many of us ruefully commented to each other that we might not be here to see the completion of the project. 


Monday, October 1, 2018

Nuclear Energy and Carbon Reduction:

A Critical Combination

I was pleased last week to have the opportunity to attend two events associated with the official rollout of a recent MIT study entitled, "The Future of Nuclear Energy in a Carbon-Constrained World."  This was an interdisciplinary study involving a number of people, both at MIT and elsewhere, some as part of the study group, and others as an advisory committee and a team of reviewers.  The co-chairs of the study were:  David Petti (also the executive director), Jacopo Buongiorno, Michael Corradini, and John Parsons.  

This study is part of a series of studies that MIT has conducted, starting in 2003, on a variety of energy related subjects, including geothermal power, coal, natural gas, solar power, and the electric grid.  Several of the previous studies dealt with nuclear-power related issues, but this one had the unique twist of focusing on the implications of nuclear energy in a future where there are constraints on carbon generation.

The first meeting of the day was held at the headquarters of the American Association for the Advancement of Science (AAAS), and the second event was a meeting of the MIT Club of Washington, DC.  The 2 programs featured most of the same speakers, so I worried that I might be bored by the second round, but that was far from the case.  The study provided a very thorough and comprehensive look at the energy supply options under a variety of assumptions, both in the US and around the world, so there was a lot to digest.  In fact, having listened to a summary of the study twice, there is still a lot more detail in the very comprehensive report linked above.

But if I could highlight one really dramatic visual take-away from the presentations--and the study--it is a graph projecting the likely cost of generating electricity under different levels of carbon restrictions and different assumptions about nuclear power.  In particular, Figure E.1 in the executive summary, below, shows that the cost of generating electricity is significantly higher for scenarios of very low carbon emissions if nuclear power is not part of the mix, both in the US and in China. 

Figure E.1 

The irony is that, the same week that I was attending these briefings, I received multiple messages regarding an initiative of a group in my home state of Maryland who are trying to gather signatures for a letter to the Maryland government urging the government to adopt a low-carbon goal for the future energy supply--but never mentioning the importance of nuclear power in doing so effectively.  When I contacted them to ask about this omission, they claimed they were not anti-nuclear, but wanted to avoid a controversial subject. 

I haven't been able to get my arms around the logic--highlight the problem, but don't mention the one option that is likely to be critical to a realistic solution.  It seems to me that this is a recipe for failure in one way or another.  And this is graphic evidence that the message about the important role nuclear power needs to play in the future still isn't fully recognized and considered in the ongoing dialogue.

So I congratulate the entire team of the MIT study for a job well done, I urge everyone to review the study, and I encourage people around the country--and the world--to share the important findings of the study with their elected officials and others so that we end up with carbon-reduction strategies that are realistic and effective.


Wednesday, September 12, 2018

Nuclear Engineering Majors Rank High:

Survey Shows High Salary, 
Low Unemployment

It seems to me that nuclear engineering often doesn't even show up as a separate field in many surveys of academic disciplines, so it caught my attention immediately when I saw a recent survey reported in Money magazine that included nuclear engineering.  It caught my attention even more when I saw that nuclear engineering was ranked third in a survey that focused largely on expected salary and employment prospects. 

The information comes from a study done by Bankrate that covers over 150 professions.  As expected, the STEM professions (science, technology, engineering, and math) generally rank higher than other professions, but to see nuclear engineering near the very top was--for me--a bit of a surprise, although, of course, a pleasant one. 

As always with such studies, one has to do a deeper dive into the methodology to understand the significance of the numbers.  What is particularly interesting about this study is that, while average salary is the most heavily weighted factor, the unemployment rate is also factored in.  On this basis, petroleum engineering, which has the highest average salary of the fields identified, but also has a high unemployment rate, doesn't make the top 10. 

With some of the current uncertainties in the prospects for new nuclear power plants, or even in the continued operation of some existing plants, some of us have been worried about whether the nuclear field can continue to attract the kind of talent that will still be needed for decades to come.  A study like this, that shows nuclear engineering to be a field with high salary potential and excellent prospects for employment, should help persuade students now choosing career fields that the nuclear engineering field is an attractive one.

Of course, there is always some danger in choosing a field just because of the job prospects.  I've been around long enough to see the job prospects dry up in some fields, and whole new fields emerge.  But under any scenario, the nuclear industry is clearly going to need trained people for a long time to come.  And furthermore, nuclear engineering has historically been a very flexible field--with roots in several engineering disciplines, nuclear engineering majors are able to work in a variety of industries.  So all prospects appear to be good for nuclear engineering majors. 


Sunday, August 19, 2018

"Secret Cities": A Look at Nuclear History

Architecture and the Manhattan Project 

I recently visited an exhibit on the Manhattan Project at the Building Museum in Washington, DC.  The exhibit has been open since early May, so perhaps some people reading this blog will have seen it already.  But if you haven't, and if you live in the DC area or have a chance to visit, I highly recommend the exhibit.  It is open until March 3, 2019, so I hope a lot of people will have the opportunity to view it.

Called "Secret Cities," the exhibit focuses on the extraordinary requirements for housing generated by the opening of Oak Ridge, Los Alamos, and Hanford laboratories during World War II, and how they were met.  This is appropriate, of course, since this is a museum about buildings and architecture, but by doing so, it focuses attention on something many of us don't think about--the fact that thousands of people had to be brought to these sites and housed, fed, and entertained, all under a shroud of secrecy.  

The exhibit puts the housing issue in context--it discusses other attempts at the time to turn out modularized housing, it includes examples of the work of some of the famous architects of the day and how their innovations influenced the designs, and it even illustrates some of the post-war housing construction that built, at least in part, upon the experiences of the Manhattan Project. 

While the exhibit focuses on the housing, it also does a good job of covering a number of other aspects of the 3 laboratories and the communities that lived there.  It includes displays that show some of the major facilities built to conduct the research and production at the laboratories, and gives brief explanations of the scientific principles that were explored and exploited.  It discusses the bombing of Hiroshima and Nagasaki, and controversy surrounding the decision to drop the bombs.  It talks about life on these remote, secret sites, and shows examples of the signs, the badges, and the announcements of social events.  And it is frank about the poor treatment of African-Americans working on the sites--the segregation and inferior housing.

The exhibit even includes a couple of pieces of Vaseline glass (also called uranium glass) and Fiestaware.  My most amusing moment in the exhibit came as I was reading that display and overheard someone behind me opining to no one in particular that it must be dangerous to eat from those dishes.  I couldn't help myself.  I turned to him and said, "Only if you eat the plate."

While a lot of the history and science covered in the exhibit will be familiar to people in the nuclear community, for me, the focus on the design and construction of the housing and on some of the memorabilia from life there at the time provided an added dimension to what I already knew.  I think others will also find that the exhibit provides a unique focus on some aspects of the Manhattan Project we too often take for granted.