1 - Path to Nuclear Engineering
Bret Kugelmass: How did you get interested in nuclear?
Margaret Harding: Margaret Harding graduated in high school in 1977, after a couple of oil embargos and there was a concern that something different needed to be done for electricity. Harding was a good mathematician and was the only girl in her high school’s computer club. She attended Iowa State University, which had just added a nuclear engineering undergraduate program to its graduate program. Iowa State was one of the Manhattan Project schools and Ames Lab figured out how to refine uranium into a metal. Nuclear was an interesting solution for energy, especially electricity, that seemed viable due to its density. Harding was the only female in her nuclear engineering graduating class of 1981. Three Mile Island occurred while she was in school, which led to the requirement for degreed engineers to be on-site during any significant maneuvers. Harding wanted to work in the nuclear design side of the industry, leading her to apply with vendors and National Labs. Her first position after graduation was with General Electric and Harding moved to San Jose, California, which was the center for G.E.’s technology expertise in nuclear. Margaret Harding’s started out working on core and fuel design for reactors.
2 - Boiling Water Reactor Physics
Bret Kugelmass: How did you decide core and fuel design was the aspect of a nuclear plant you wanted to work on?
Margaret Harding: Many of the jobs in the nuclear industry don’t require a degree in nuclear, but Margaret Harding was always interested in the physics of a nuclear plant. As a child, Harding took her father’s flute apart to clean it and successfully put it back together. As an adult, she also put together her own computers, which inspired her son to learn how to take apart computers and put them back together and led to his engineering degree. Harding was amazed by the concentration of neutrons in an area in a reactor. In school, the focus is concentrated on solid coolants and solid moderators, so pressurized water reactors are the favorite to study. Modeling phase changes are very difficult, but G.E. has very powerful tools to model these changes. Harding was also fascinated by G.E.’s boiling water reactors’ ability to oscillate power production. In physics, bubbles allows for the elimination of the secondary heat exchanger, which has been a major issue is many pressurized water reactors. In boiling water reactors, there are more voids and less water which slows the neutrons down so they are more likely hit a U-235 atom on the split. If the neutrons move faster, they are more likely to be absorbed by U-238 which will disintegrated into fissile plutonium-239. Lowering the flow at the beginning of the cycle moves voids to the top of the core, allowing build-up of plutonium at the core, producing more fuel and providing lower enrichment. Steam goes through a separator and dryer before moving to the turbine, in order to prevent wet steam from going through a high speed turbine.
3 - Tritium and Plutonium
Bret Kugelmass: Is tritium a concern in boiling water reactors?
Margaret Harding: All nuclear reactors generate tritium, which is a naturally occurring element in the ocean, but anti-nuclear people use tritium to drive fear into the local population. Margaret Harding was a national spokesperson for the American Nuclear Society (ANS) after Fukushima and did some coverage on tritiated water. Disposal of tritiated water is a political issue, not a technical one. Tritium is also used in a lot of products, but the supply is already much greater than the demand. As spokesperson for the ANS, Harding answered questions about the presence of plutonium at the Fukushima site. Due to the two atomic bombs that went off in Japan, an analysis had to be done to determine the mix of isotopes and Harding was fairly confident that it did not come from the reactors. Plutonium is not water soluble and doesn’t get picked up in steam, so it doesn’t move very well. Plutonium is only really dangerous if you ingest it. While at General Electric, bundles would be stored in the Bundle Forest where they would hang in open air. People were asked to wear gloves to avoid getting body oils on the fuel. Also, the main radiation off fresh uranium is alpha, which is stopped by clothing and gloves.
4 - International Collaboration in Commercial Nuclear
Bret Kugelmass: What are some of the international considerations when thinking about nuclear fuel?
Margaret Harding: The first nuclear technologies were developed in the United States during World War II and were being driven towards a weapon to stop the war, not knowing where it would be deployed. Controlled reactions were already being run in Chicago. Post-World War II, the initial Atomic Energy Act said only the military could utilize nuclear technology. President Eisenhower was looking for a way to change the pat of nuclear technology. He stood up in the United Nations and introduced Atoms for Peace, calling for global interactions and international efforts, even before the U.S. had commercial nuclear technology and efforts. Eisenhower’s Cabinet wrote the 1954 version of the Atomic Energy Act, which said you can’t cooperate without the permission of the Atomic Energy Commission. This allowed U.S. commercial entities to dabble in nuclear technology; until this point, the purview was the Navy. Westinghouse decided to do pressurized water reactors (PWR’s) and G.E. decided to pursue boiling water reactors (BWR’s). The government was pushing nuclear reactors at the point to have other options besides coal and subsidized early reactors. So many reactors were built near Pittsburgh because it was the center of steel production. They needed to figure out how to stop burning so much coal in the region for steel production because it was turning the city black. U.S. companies started partnering with France, England, and Japan. Japan, like France, has no natural resources and was importing coal and gas. Today, nuclear becomes a national asset in many countries.
5 - Nuclear Export via Part 810
Bret Kugelmass: Does there a right level of control beyond the political side of nuclear and into the engineering side of nuclear?
Margaret Harding: To some degree, there is a right level of control on the engineering side of nuclear. General Electric built two reactors in India in the late 1960’s and early 1970’s, Terapur 1 and 2. India had a nuclear explosion, causing the U.S. to go up arms. G.E. was pushed out of India, but they were still allowed to send self service implementation letters to India to notify them of technical problems and solutions identified for the reactors. In nuclear, an accident anywhere is an accident everywhere, so everyone must be kept operating safely. China isn’t good about protecting intellectual property, but we want to make sure they are safe. Part 810 is an outgrowth of the Atomic Energy Act. There are criteria for how to get permission for developing nuclear and the U.S. has bilateral agreements for most countries that are big in the nuclear realm to provide general permission to operate. Other countries require specific authorization, which the U.S. is willing to provide to ensure programs are developed safely and prevent other leading countries from building those relationships. The touchpoint with nuclear power plants is the fuel and outage maintenance work. Some countries can’t afford to build a big light water reactor and don’t have the grid to support it, so they may be looking at small modular reactors (SMR’s). Per Part 810, the U.S. can’t sell a reactor until a 123 agreement exists between the countries. In order to get conversations going to get a 123, companies can go do public marketing in other countries. Giving the government a sense of what the industry is interested in gives a target for 123 agreements. The Commerce Department trade division has trade representatives in a lot of countries who will happily set up meetings with the right people for free. Countries first need to build an infrastructure, which is laid out in the International Atomic Energy Agency steps to building a nuclear power plant. Companies owned by governments are less interested in profit, but more interested in jobs and relationships. Countries like Russia are willing to cut off energy to countries they operate in to get what they want.
6 - Electricity Market Control
Bret Kugelmass: Why are countries interested in buying Russian reactors?
Margaret Harding: Some countries don’t have financing to build their own reactors and the Russians offer a sweet deal in building, owning, and operating reactors. When Ukraine abandoned their Russian satellite state and wanted to join the European Union, Russia cut off the fuel supply to the Russian-built reactors in Ukraine. Through the United Nations and other policies, the world is less prone to aggressive land grabs. Humans still like to control and be bigger than they are, not by taking land anymore, but in other ways. China convinced Sri Lanka to build a second port. Sri Lanka couldn’t afford the payments to China, who had financed the construction of the port, so China now owns the port. Electricity should not be considered a private market. When power outages occur, such as in Puerto Rico, people die and lives are disrupted. Water is not considered a private market, but is a government-run entity because clean water is considered a basic necessity of life. Electricity should fall into this same category. Electricity used to be a cost-plus market with oversight by the Public Utility Commission. The current model is market-based, so independent power producers can bid wherever they are happy. Nuclear plants struggle in these markets because natural gas can be or not be available and wind and solar are preferentially chosen. Nuclear plants are funded as a base load due to the economics of plant revenue.
7 - Rethinking Electricity Infrastructure
Bret Kugelmass: Why can’t nuclear get “must-run” laws like renewables?
Margaret Harding: Some states have begun to rethink a clean portfolio standard as opposed to a renewable portfolio standard. Nuclear is just as good as the renewables in low-carbon energy production. Nuclear was left out because supporters of renewables saw that nuclear power would overwhelm the clean energy production standard for the grid and renewables would never be called on. The issue of climate change needs to be recognized as a critical issue on a country basis and a global basis. The United States should set the example of producing electricity without carbon. The infrastructure of the current plant designs were intended to be temporary because they were easier to build and initially operate. Rickover liked water because it was easy to run in the ocean and the more advanced coolant reactors - sodium, molten salt, high temperature gas - were more difficult to develop initially. Electricity should be considered a fundamental for life. People should have electricity when they need it on a reliable basis. Voltage regulation is also a big deal in production of clean energy. The U.S. has gotten complacent about electricity and the country needs to rethink how it approaches energy production and distribution.