Tag Archives: nuclear energy

Admiral’s comments on fission hold for fusion 70 years later

2 Replies

Last month the US Energy Secretary, Jennifer Granholm announced a successful experiment at the Lawrence Livermore National Laboratory in which 192 lasers were used to pump 2.05 mega Joules of energy into a capsule heating its contents to 100 million degrees Centigrade causing fusion of hydrogen nuclei and the release of 3.15 mega Joules of energy.  An apparent gain of 1.1 mega Joules until you take account of the 300 mega Joules consumed by the 192 lasers.  The reaction in the media to this fusion energy experiment and the difficulties associated with building a practical fusion power plant, such as the Spherical Tokamak Energy Production (STEP) project in the UK (see ‘Celebrating engineering success‘ on November 11th, 2022) reminded me of a well-known memorandum penned by Admiral Rickover in 1953.  Rickover was first tasked, as a Captain, to look at atomic power in May 1946 not long after first human-made self-sustaining nuclear chain reaction was initiated in Chicago Pile #1 during an experiment led by Enrico Fermi in 1942.  He went on to become Admiral Rickover who directed the US Navy’s nuclear propulsion programme and the Nautilus, the first nuclear-powered submarine was launched in 1954.  With thanks to a regular reader of this blog who sent me a copy of the memo and apologies to Admiral Rickover, here is his memorandum edited to apply to fusion energy:

Important decisions about the future of fusion energy must frequently be made by people who do not necessarily have an intimate knowledge of the technical aspects of fusion.  These people are, nonetheless, interested in what a fusion power plant will do, how much it will cost, how long it will take to build and how long and how well it will operate.  When they attempt to learn these things, they become aware the confusion existing in the field of fusion energy.  There appears to be unresolved conflict on almost every issue that arises.

I believe that the confusion stems from a failure to distinguish between the academic and the practical.  These apparent conflicts can usually be explained only when the various aspects of the issue are resolved into their academic and practical components. To aid in this resolution, it is possible to define in a general way those characteristics which distinguish one from the other.

An academic fusion reactor almost always has the following basic characteristics: (1) It is simple. (2) It is small.  (3) It is cheap. (4) It is light. (5) It can be built very quickly. (6) It is very flexible in purpose . (7) The reactor is in the study phase.  It is not being built now.  On the other hand, a practical fusion reactor can be distinguished by the following characteristics: (1) It is being built now.  (2) It is behind schedule. (3) It is requiring an immense amount of development on apparently trivial items. (4) It is very expensive. (5) It takes a long time to build because of the engineering development problems. (6) It is large. (7) It is complicated.

The tools of the academic-reactor designer are a piece of paper and a pencil with an eraser. If a mistake is made, it can always be erased and changed.  If a mistake is made, it can always be erased and changed.  If the practical-reactor designer errs, they wear the mistake around their neck; it cannot be erased.  Everyone can see it. 

The academic-reactor designer is a dilettante.  They have not had to assume any real responsibility in connection with their projects.  They are free to luxuriate in elegant ideas, the practical shortcomings of which can be relegated to the category of ‘mere technical details’.  The practical-reactor designer must live with these same technical details.  Although recalcitrant and awkward, they must be solved and cannot be put off until tomorrow.  Their solutions require people, time and money.

Unfortunately for those who must make far-reaching decisions without the benefit of an intimate knowledge of fusion technology and unfortunately for the interested public, it is much easier to get the academic side of an issue than the practical side. For the large part those involved with academic fusion reactors have more inclination and time to present their ideas in reports and orally to those who will listen.  Since they are innocently unaware of the real and hidden difficulties of their plans, they speak with great facility and confidence.  Those involved with practical fusion reactors, humbled by their experiences, speak less and worry more.

Yet it is incumbent on those in high places to make wise decisions, and it is reasonable and important that the public be correctly informed.  It is consequently incumbent on all of us to state the facts as forth-rightly as possible.  Although it is probably impossible to have fusion technology ideas labelled as ‘practical’ or ‘academic’ by the authors, it is worthwhile both authors and the audience to bear in mind this distinction and to be guided thereby.

Image: The target chamber of LLNL’s National Ignition Facility, where 192 laser beams delivered more than 2 million joules of ultraviolet energy to a tiny fuel pellet to create fusion ignition on Dec. 5, 2022 from https://www.llnl.gov/news/national-ignition-facility-achieves-fusion-ignition

Horsepower driving ambition

Leave a reply

A photograph of 'Physical Energy' in Kensington Gardens - a sculpture of a man on a horseWalking across Kensington Gardens in London last week, on my way to attend a conference on Carbon, I came across the sculpture in the picture.  It is ‘Physical Energy’ by George Frederick Watts (1817 – 1904), which really confused me because I automatically started thinking about the sort of energy that is associated with horsepower.  Horsepower is a unit of power (energy per unit time) developed by James Watt (1736 – 1819) to evaluate the output of his steam engines.  The plaque below the sculpture calls it a ‘sculptural masterpiece; a universal embodiment of the dynamic force of ambition’ and states that the artist described it as a ‘symbol of that restless physical impulse to seek the still unachieved in the domain of physical things.’  So, while the connections seemed obvious to me, it would appear that Watts was not inspired by Watt.

The conference was interesting too.  There were delegates from all over the world presenting research on a wide range of topics from new designs of batteries to using carbon as an sorbent for toxins, carbon-based composites and self-assembly of metal-organic meso-crystals.  Two students that I have supervised were presenting their research on establishing credibility for models of the graphite core in nuclear power plants and on algorithms for identifying the surface morphology in samples of graphite.

Conversations about engineering over dinner and a haircut

7 Replies

For decorative purposes: colour contour map of a face mask produced using fringe projectionRecently, over dinner, someone I had just met asked me what type of engineering I do. I always find this a difficult question to answer because I am sure that they are just being polite and do not want to hear any technical details but I find it hard to give an interesting answer without diving into details. Earlier the same day I had given a lecture on thermodynamics to about 300 undergraduate students so I told my inquisitor about this experience and explained that thermodynamics was the science of energy and its transformation into different forms. Then, I muttered something about being interested in making and using measurements to ensure that computational models of aircraft and nuclear power stations are reliable and the conversation quickly moved on. A week or so earlier, I was having my hair cut when the barber asked me a similar question about what I did and I told him that I was a professor of engineering which led to a conversation about robots. We speculated about whether we would ever lose our jobs to robots and decided that we were both fairly secure against that threat. There is a high degree of creativity in both of our roles – while I always ask for the same haircut, my hair is in a different state every time I visit the barbers’ and I leave looking slightly different every time. I don’t think that I would like the uniformity that a row of robots in the barbers’ shop might produce. And, then there is the conversation during the haircut. A robot would need to pass the Turing test, i.e., to exhibit intelligent behaviour indistinguishable from a human, which no computer has yet achieved or is likely to do so in our lifetime, at least not a cost that would allow them to replace barbers. The same holds for professors – the shift to delivering lectures online during the pandemic might have made some professors worry that their jobs were at risk as recorded lectures replaced live performances; however, student feedback tells us that students have a strong preference for on-campus teaching and the high turnout for my thermodynamics lectures supports that conclusion.

Footnotes:

For a new website I was asked to describe my research interests in about 25 words and used the following: ‘the acquisition of information-rich measurement data and its use to develop digital representations of complex systems in the aerospace, biological and energy sectors’.  Fine for a website but not dinner conversation! 

There have been some attempts to build a robot that cut your hair, for example see this video. 

Image shows a colour contour map describing the shape of a facemask produced using fringe projection which could be used as part of the vision system for a robotic barber.  For more information on fringe projection see: Ortiz, M. H., & Patterson, E. A. (2005). Location and shape measurement using a portable fringe projection system. Experimental mechanics, 45(3), 197-204 or watch this video from the INDUCE project that was active from 1998 to 2001.

Bringing an end to thermodynamic whoopee

2 Replies

Two weeks ago I used two infographics to illustrate the dominant role of energy use in generating greenhouse gas emissions and the disportionate production of greenhouse gas emission by the rich [see ‘Where we are and what we have‘ on November 24th, 2021].  Energy use is responsible for 73% of global greenhouse gas emissions and 16% of the world’s population are responsible for 38% of global CO2 emissions.  Today’s infographics illustrate the energy flows from source to consumption for the USA (above), UK and Europe (thumbnails below).  In the USA fossil fuels (coal, natural gas and petroleum) are the source of nearly 80% of their energy, in the UK it is a little more than 80% and the chart for Europe is less detailed but the proportion looks similar. COP 26 committed countries to ending ‘support for the international unabated fossil fuel energy sector by the end of 2022’ and recognised ‘investing in unabated fossil-related energy projects increasingly entails both social and economic risks, especially through the form of stranded assets, and has ensuing negative impacts on government revenue, local employment, taxpayers, utility ratepayers and public health.’  However, to reduce our dependency on fossil fuels we need a strategy, a plan of action for a fundamental change in how we power industry, heat our homes and propel our vehicles.  A hydrogen economy requires the production of hydrogen without using fossil fuels, electric cars and electric domestic heating requires our electricity generating capacity to be at least trebled by 2050 in order to hit the net zero target. This scale and speed of  transition to zero-carbon sources is such that it will have to be achieved using an integrated blend of green energy sources, including solar, wind and nuclear energy.  For example, in the UK our current electricity generating capacity is about 76 GW and 1 GW is equivalent to 3.1 million photovoltaic (PV) panels, or 364 utility scale wind turbines [www.energy.gov/eere/articles/how-much-power-1-gigawatt] so trebling capacity from one of these sources alone would imply more than 700 million PV panels, or one wind turbine every square mile.  It is easy to write policies but it is much harder to implement them and make things happen especially when transformational change is required.  We cannot expect things to happen simply because our leaders have signed agreements and made statements.  Now, national plans are required to ween us from our addiction to fossil fuels – it will be difficult but the alternative is that global warming might cause the planet to become uninhabitable for us.  It is time to stop ‘making thermodynamic whoopee with fossil fuels’ to quote Kurt Vonnegut [see ‘And then we discovered thermodynamics‘ on February 3rd, 2016].

 

 

 

 

 

 

 

 

 

Sources:

Kurt Vonnegut, A Man without a Country, New York: Seven Stories Press, 2005.  He wrote ‘we have now all but destroyed this once salubrious planet as a life-support system in fewer than two hundred years, mainly by making thermodynamic whoopee with fossil fuels’.

US Energy flow chart: https://flowcharts.llnl.gov/commodities/energy

EU Energy flow chart: https://ec.europa.eu/eurostat/web/energy/energy-flow-diagrams

UK Energy flow chart: https://www.gov.uk/government/collections/energy-flow-charts#2020