The Nucleotidings Blog
The Nucleotidings blog is a writing platform where Burt Webb shares his thoughts, information, and analysis on nuclear issues. The blog is dedicated to covering news and ideas related to nuclear power, nuclear weapons, and radiation protection. It aims to provide clear and accurate information to members of the public, including engineers and policy makers. Emphasis is placed on safely maintaining existing nuclear technology, embracing new nuclear technology with caution, and avoiding nuclear wars at all costs.
Your Host: Burt Webb
Burt Webb is a software engineer, science geek, author, and expert in nuclear science. Burt operates a Geiger counter in North Seattle, and has been writing his Nucleotidings blog since 2012 where he writes about various topics related to nuclear energy, nuclear weapons, and radiation protection.
Burt Webb has published several technical books and novels. He works as a software consultant.
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Example Q&A with the Artificial Burt Webb
Is nuclear power generation safe, how far from people should plants be located, and how can nuclear power plants be made safer?
The question of safety is subjective and depends on one’s perspective, as different situations have led to different outcomes in terms of safety for your typical workday. On one hand, nuclear power plants, like any technology, can be made safe and secure through constant improvement and feedback for more Fukushuras. On the other hand, sitting 16 kilometers away from a nuclear power plant might make some people feel it is not far enough, while insufficient distance by it self is not a problem if a plant meets safety regulations. Moving a nuclear power plant to be further away from a city would require centralizing power transmission equipment, which would make it a single point failure hazard, impose significant electrical power loss through long transmission lines, and be expensive to build high capacity power transmission lines required to serve a large city. Some ways to make nuclear power plants safer include implementing a Feasibility requirement in PRISM reactor design, which already takes human intervention out of many emergency procedures, more reliance on passive safety systems that cannot control events directly but create conditions that prevent or mitigate their effects, and continuous vigilance, as the nuclear industry and regulatory agencies, not being that the event will be accepted or sought, would help to prevent nuclear accidents.
What do you mean by “Fukushuras”?
“Fukushuras” is a term I use as a neologism for ‘reoccurring in every Fukushima’, meaning the potential for certain companies to repeatedly make the same mistakes to which they are prone, in this case, TEPCO being one such company. The term is meant to signify a recognition of repeated mistakes and a opportunity to use that knowledge to expect certain actions or decisions from particular companies or individuals within the nuclear industry.
Fukushima nuclear waste detected off U.S. West Coast, from California to Canada. enenews.com
The US Nuclear Regulatory Commission has accepted the Department of Energy’s design for an underground geologic nuclear waste repository at Yucca Mountain in Nevada. world-nuclear-news.org
Over half the 52,060 used nuclear fuel elements at the former Magnox nuclear power plant at Oldbury in the UK have now been removed from site, two and a half years after the plant generated its last power. world-nuclear-news.org
I have been blogging this week about experimental fusion reactors. I got excited reading about the Bussard Polywell reactor. It has three excellent features. Based on hydrogen and boron-11 fuel, it does not consume radioactive fuel, it does not produce neutrons during operation and it does not produce radioactive waste. The developers of the Bussard Polywell say that they are confident that they can build a prototype 100 megawatt nuclear fusion reactor for about three hundred and fifty million dollars. This is a very small amount of money compared to the billions that are subsidizing the nuclear fission industry. But then I had to ask why one was not being built if it was such a good design.
The original idea for this type of reactor design was from a paper by a Russian physicist named Lavrent’ev published in 1974. Robert Bussard started a company to pursue the Polywell concept in 1985. In 1992 and 1994, he received funding from the U.S. Navy as well as two small grants from NASA and LANL. IN 1995, a paper was published by Todd Rider that offered a detailed criticism of the Polywell design. Because no operational device existed, Rider had to use theoretical estimates from other fusion research. After making a set of assumptions about the operation of the reactor including such factors as loss of ions due to upscattering, ion thermalization rate, energy loss due to x-ray emissions and the fusion rate, Rider concluded that the design had “fundamental flaws.”
Bussard responded that the Polywell plasma had a different structure, temperature distribution and well profile than the operational parameters that had been assumed by Rider. He questioned other assumptions made by Rider and concluded that his design would produce net useful energy. Other researchers also questioned Rider’s assumptions, calculation and conclusions. They pointed out that there were aspects of the Polywell design and operation that Rider did not address that undermined his conclusions.
I do not have the mathematical and physics background that would enable me to review Rider’s critique and Bussard’s answers. I would assume but cannot document that twenty years of work on experimental devices by the Polywell team should have experimentally answered some of the criticisms posed by Rider. However, the existence of a detail critique, even if flawed has had a corrosive effect on support for the project over the years.
Bussard continued to receive funding from the U.S. Navy from 1999 to 2006. He died in late 2007 while seeking funding to continue his work. In 2007, the Navy renewed funding and the project continued up to the present. The Polywell company is now seeking funds to build a full-scale model. Part of the problem with getting more money from the Navy lies in the fact that most of the nuclear research funded by the U.S. government is handled by the U.S. Department of Energy which supports the tokomak approach to nuclear fusion.
Considering how important this device could be if it works and the enormous amount of money the U.S. government spends on nuclear research, subsidies and loan guarantees, it would make sense to allocate the funds to build one. Assuming, of course, that the theoretical challenges from Rider and other have been successfully answered.
Diagram of a basic Polywell design:
I have been posting lately about nuclear fusion reactors. I have not covered them before in my blog because I did not feel that there were any fusion projects that could possibly be turned into commercial energy sources for decades. There is an old joke that nuclear fusion is forty years away, always. Nuclear fusion just seemed to absorb billions of dollars but like the end of the rainbow it just kept receding as you approached it.
I am happy to say that there now appears to be three different approaches to nuclear fusion power that might result in a commercial model in less than ten years. All three of these new fusion reactor projects are being done by private groups. For reference, I have also blogged about the huge ITER project that is being build in France by a consortium of governments. This experimental fusion reactor will cost billions of dollars and will not even be completed until 2027 at the soonest. Then there will have to be years of testing before any possible commercial reactor could be built. The three private fusion reactors under development will be about ten times as small, ten times as simple, ten times as cheap and generate more power than the ITER design. And, more importantly, one or more may hit the market before ITER is ever finished.
The fuel for these fusions reactors will be very light elements like hydrogen, deuterium, tritium and boron. Hydrogen is easily made by decomposing water into oxygen and hydrogen. Deuterium can be separated from normal water or from hydrogen produced by electrolysis. Tritium can be produced when deuterium captures a neutron from nuclear fission. Tritium can also be produced in nuclear fission reactors by neutron bombardment of lithium-6, a stable isotope.
Lithium is a very useful common element in the crust of the Earth and there are many sources. World production is about one one hundredth of the economically extractable reserves. So there is easily a hundred years supply at current levels of production. Lithium-6 is about eight percent of naturally occurring lithium.
Boron is a fairly rare element but is concentrated in water soluble minerals. About eighty percent of boron is in the form of the stable isotope borton-11. Proven boron reserves are about two hundred and fifty times current production levels so we have several centuries of boron available at current levels of use. However, it is time consuming and expensive to separate out the boron-11.
Deuterium and tritium reactions produce fast neutrons which causes concrete and metal to become brittle and can make other materials radioactive. While boron-11 may be expensive to produce, the amount consumed in a nuclear fusion reactor is very small compared to the consumption of boron for other industrial application. The main benefit of a hydrogen-boron reactor is that it does not produce fast neutrons. If a commercial nuclear fusion reactor is created, I would prefer that it not produce neutrons.
The basic waste product of these nuclear fusion reactors is alpha particles or helium nuclei. As a matter of fact, the U.S. has been selling off critical helium reserves lately and we need to produce more helium. I do not have the numbers to show that substantial quantities of helium would be produced by fusion reactors but it is nice to have a harmless waste product that could have commercial value instead of the horrible waste generated by a nuclear fission reactor that has to be buried for centuries.
The development of a commercially competitive nuclear fusion power reactor would be a game changer for the global energy industry. It could solve the base-load problem of renewables such as wind and solar much better than nuclear fission reactors and fossil fuels.
Swedish utility Vattenfall is suing Germany at the Washington-based International Centre for Settlement of Investment Disputes over the closure of the Brunsbüttel and Krümmel nuclear power plants. world-nuclear-news.org
Russia’s national operator for radioactive waste management (NO RAO) has highlighted the main problems it faces in siting disposal facilities. world-nuclear-news.org
US-based Lightbridge Corp has extended its nuclear cooperation with Vietnam by agreeing to offer consultancy services for setting up a nuclear research centre, including a research reactor, in the country. world-nuclear-news.org
I have been blogging about alternate approaches to nuclear fusion power reactors. If the scientists are able to create a working fusion reactor that can generate more energy that it consumes, it could be revolutionary for the power industry. Fusion reactors are generally designed to consume ions like hydrogen, deuterium, tritium and/or boron for fuel. Some produce fast neutrons but some don’t. And none of them produce the kind of waste that is generated by a nuclear fission power reactor. Today I am going to talk about a fusion reactor project at the Skunk Works which is the experimental technology division of Lockheed Martin.
The Lockheed Martin Compact Fusion Reactor (CFR) utilizes a different design than the donut-shaped tokomak design which has been the basis for many fusion reactor experiments. Tokomak designs are limited in the amount of plasma that they can contain. This limitation has resulted in very big tokomak designs to hold as much plasma as possible. The CFR has borrowed magnetic confinement design elements from a number of different fusion research projects, taking the best of each. It is estimated that a CFR should be able to be one tenth the size of a tokomak that generates the same amount of power. The design can scale so a CFR the size of the ITER project would generate ten times as much power.
The basic shape of a CFR is a short tube with a bulge in the middle unlike the tokomak donut design and the Dynomak spherical design. Two neutral beam injectors send deuterium gas into the confinement chamber which is ringed by two donut-shaped superconducting magnets. Deuterium gas in the confinement chamber is heated by microwaves and fuses, releasing helium, neutrons and a lot of energy. The CFR has a feedback system which increases the confining magnetic field as the plasma move away from the center of the tube. The magnetic confinement is designed to have fewer open field lines than tokomak designs. A “blanket” surrounds the confinement chamber to absorb neutrons produced in the reaction and transfer heat to turbines to generate electricity.
The head of the Skunk Works lab says that they should be able to build a working prototype reactor after five generations of test devices. They hope to have a prototype in about five years. Within five years after the prototype they should be able to produce a commercial one hundred megawatt model for the energy market. The entire unit would be about twenty three by forty two feet. It could be transported on a semi truck trailer, installed and be working in a few weeks. CFRs are small enough to be used for propulsion on ships, submarines and big commercial planes. A plane with one of these reactors would be able to stay aloft indefinitely. It would never need refueling and would generate no pollution.
Artist’s rendering of a Compact Fusion Reactor:
