by mark reed January 13, 2012
 The bomb ended the war. We conceived nuclear technology, and in a time of great desperation, we used it for destruction. The scientists who invented it foresaw its potential to dehumanize, but those same prescient scientists also foresaw its potential to benefit humanity. They sought to redeem what they had created. The power of fission had already been unleashed for barbarism - now the challenge was to harness it for munificence.
This challenge weighed heavily on President Truman, who had ordered the bombs dropped. One year later, in August of 1946, he signed the Atomic Energy Act, which authorized the civilian use of nuclear energy '1'. The U.S. government had brought nuclear technology into the world, and that couldn’t be reversed – Fermi’s innovation beneath those bleachers in Chicago was here to stay. Thus, the U.S. government had a responsibility to the world to foster and facilitate its peaceable applications while guarding against its savage applications.
While nuclear weapons would remain cloistered by the government, nuclear reactors were anyone’s game. The secret was out. Despite their common origin, these two technologies would sharply diverge.
The world’s first man-made nuclear reactor was the Chicago Pile – Fermi’s crude heap of uranium and graphite blocks. Subsequently, the Manhattan Project covertly constructed the world’s first large-scale reactor at the Hanford Site in the deserts of eastern Washington State. Its purpose was to breed plutonium for the bombs - when a uranium atom absorbs a neutron and doesn’t fission, it often morphs into a plutonium atom. The next natural step was to design and develop a large-scale reactor optimized to produce a long-term steady flow of electricity.
The two most important aspects of nuclear reactor design are the choices of fuel and coolant. The fuel must contain a fissionable material - some combination of uranium, plutonium, or thorium - but it can take on just about any chemical form. It can be solid or liquid. If solid, it can be a metal or a ceramic. If liquid, it can be a molten salt or an aqueous solution.
The coolant’s primary purpose is to transport energy from the fuel to a turbine to generate electricity, but it also (sometimes incidentally and sometimes purposefully) serves to modify the behavior of the neutrons so that they can more or less readily spur fission in the fuel. Coolants can be liquids or gases. The wide range of coolants proposed or actually incorporated into real reactors includes light water, heavy water, sodium, sodium-potassium, lead, lead-bismuth, various molten salt mixtures, various organic compounds, helium, carbon dioxide, and even mercury.
Each of these coolants has advantages and disadvantages in terms of its thermal and chemical properties, and each constrains the neutron behavior and thus the fission reaction and fuel composition. The fuel and coolant are interwoven such that nuclear design is an intricate process of weighing and optimizing the multifaceted interactions between the two.
After Truman signed the Atomic Energy Act, a twenty-year global nuclear frenzy ensued. Scientists and engineers from around the world proposed all sorts of exotic designs with every conceivable combination of fuel and coolant for every conceivable application. Government laboratories actually built a surprising number of these – in the deserts of Idaho and Washington, atop the plateaus of New Mexico, along the oak ridges of Tennessee, and in even within many small cities '2'. However, none of this caught on in the private sector. The dream of nuclear energy as a commercial enterprise was unrealized.
Like most dreams, realization would require a single person with conviction, vision, and drive.
Hyman G. Rickoverwas born to a Jewish family in Poland in 1900. At that time, much of what is now Poland was divided between the Russian and Prussian Empires. Rickover’s family fled to the U.S. in 1905 to avoid pogroms. He grew up in working-class Chicago and, after a chance acquaintance with a congressman, was nominated for admission to the U.S. Naval Academy. He thus began his military service upon matriculation in 1918 '3'.
Rickover’s naval career was marked by assiduity and asperity, charisma and controversy. He served on submarines in the 30’s and distinguished himself during WWII as “a man who gets things done” '4'. However, he also had a knack for controversy, and his sharp tongue made him just as many enemies as friends. He was initially passed over for promotion to admiral twice, even as he became famous for his accomplishments. Had Congress not eventually intervened to force his promotion, he would not be known today as “Admiral” Rickover. He was a dynamo, but he was not popular.
Following the war, the Navy developed an interest in nuclear technology. At that time, ships and submarines were limited by how long they could sail or remain submerged without refueling. However, with nuclear energy, these vessels could operate continuously for extremely long periods of time on only a small quantity of uranium fuel. Submarines could remain submerged for months, an entire war patrol. Rickover represented the Navy in a government project to develop nuclear power plants in Oak Ridge, Tennessee. There he worked with physicists who had been on the Manhattan Project.
Three years later, in 1949, the Navy appointed Rickover to head a new program to develop nuclear-powered submarines. He chose to design and develop a reactor cooled by light water and fueled by uranium oxide (a solid ceramic) clad with a zirconium shell. After five years of work, the world’s first nuclear-powered submarine, the USS Nautilus, was commissioned and launched. This was an astounding feat, as the design methods and physics data that today’s nuclear engineers require simply did not exist yet. Furthermore, the reactor was nestled within a submarine hull twenty-eight feet in diameter, while other reactors built in the 1950’s were as large as city blocks. The USS Nautilus demonstrated her ability to remain submerged for exceptionally long periods of time by becoming the world’s first vessel to sail beneath the North Pole, traversing the polar ice cap from the Pacific to the Atlantic.
Rickover’s light water reactor was not only superb for naval vessels - it was also amphibious. Four years after the USS Nautilus set sail, Rickover oversaw completion of a land-based light water reactor: the Shippingport Atomic Power Station in Pennsylvania. It was connected to the electric grid, making it “the world’s first full-scale atomic electric power plant devoted exclusively to peacetime uses” '5'. Rickover had completed nuclear technology’s transition from an instrument of war to an instrument of peace.
Although many other reactor designs were pursued and advocated, light water won out. In 1960, General Electric built the first privately financed nuclear plant. It was light water. It had uranium oxide fuel clad with zirconium, just like Rickover’s original design. The remainder of the 60’s saw a flurry of plant construction – nearly all of them light water. Today, light water cools over 80% of commercial reactors worldwide '6'.
Throughout the 60’s and 70’s, the aging Rickover continued to serve, and his prominence only grew. He achieved legendary status, and much of the Navy became a cult of his personality. He did things differently. Officers under his command were forbidden to wear uniforms, because ensigns often lectured to captains or admirals on nuclear physics. This egalitarian practice was unheard-of, even heretical, in an organization where rank is everything, but Rickover had his way. The nuclear navy was his fiefdom, and only his rules applied.
His political capital began to wane only after the Three Mile Island accident in 1979, which, although unrelated to the Navy, spurred a nationwide distrust of all things nuclear. Finally, in 1982, President Reagan relieved the curmudgeonly eighty-one-year-old admiral of his command. This ended Rickover’s sixty-three years of active service, the longest tenure of any naval officer in U.S. history.
President Nixon most aptly encapsulated the greatness of Rickover when he acknowledged the fortune that “this man, who was controversial, this man, who comes up with unorthodox ideas, did not become submerged by bureaucracy, because once genius is submerged by bureaucracy, a nation is doomed to mediocrity” '7'. Although he never profited from his work, he is the closest thing nuclear technology has to a seminal entrepreneur.
I was twenty-one when I met Steve Jobs.
Upon returning to the U.S. from my randonneuring expedition in Japan, I immediately went to Silicon Valley for an internship at Apple. This was a rather unusual thing for a physics and nuclear engineering student to do, as Apple occupies an engineering niche that has no direct relation to those fields of study. I was taking a hiatus from my studies for some introspection to figure out who I was and whether I wanted to continue on my current path or pull a hairpin turn. Part of that was my quixotic trek in Japan, and another part of that was immersing myself in something alien.
I spent four months at Apple. I was a project management intern for the iPhone 3G. I certified Bluetooth for the June release, and I organized the motley of global cellular network settings for the initial expansion into international markets. I learned about technical subjects that were foreign to me. I also learned some of the truth behind Apple folklore, including the fact that Apple products are white, smooth, and shiny only because Jonathan Ive, Apple’s chief designer, began his career designing toilets. The culture of the place was enveloping and magnificent. It was new. It was “insanely great”.
Then I met Steve Jobs in the cafeteria. A few weeks later I heard him speak to a group of young employees. He gave us the same advice he gave to so many other millennials: “Don’t settle.”
“Your work is going to fill a large part of your life, and the only way to be truly satisfied is to do what you believe is great work. And the only way to do great work is to love what you do. If you haven’t found it yet, keep looking. Don’t settle. As with all matters of the heart, you’ll know when you find it. And, like any great relationship, it just gets better and better as the years roll on. So keep looking until you find it. Don’t settle” '8'.
Like so many other millennials, those words spoke to me. Consumer electronics, especially Apple’s creative brand of it, was exciting. However, it wasn’t for me. The work was interesting and worthwhile, but it wasn’t difficult for me to put down at the day’s end. It didn’t tickle. After seven hundred miles in Japan and four months at the forefront of innovation at Apple, I had the answer to my introspection: “keep looking”.
I returned to MIT and plodded through the remainder of my undergraduate studies. I stayed there for a master’s degree mostly by default, without any real ambition. Then, at the end of my first year of graduate school, I found it. Things clicked. Neutrons are beautiful. I don’t know what they look like, but they’re beautiful. They don’t emit light, but they shine.
I sat down that summer and really sunk into my research for the first time. I squeezed the juice out of it, and then I ate the rind. Steve Jobs told me to keep looking. I left Apple, and now I’m a nuclear engineer. I love what I do, and I won’t ever settle.
Steve Jobs was to personal computing and personal music experience what Admiral Rickover was to nuclear technology. Like Rickover, he was abrasive and brusque, even callous. He believed things. He riled people. He founded Apple in his parent’s garage, built it up from nothing into a legendary company…and then got ousted. Yes, he was ousted from his own company. How does that happen? It doesn’t, unless you speak your mind to the point of alienating people.
Admiral Rickover was anything but a conformist – he bucked the Navy establishment and riled his superiors. He bucked bureaucracy and innovated. Though many viewed him as cantankerous, it was precisely this tendency to challenge authority in vigorous pursuit of what he believed in that enabled him to pioneer the nuclear Navy.
Innovation is about thinking differently. It’s about challenging the status quo, ignoring directions in pursuit of new ideas. Creativity and passion are the two most important ingredients for innovation, much more important than sycophantically following all the rules to please people. Obsequiousness and schmoozery are no virtues – they thwart innovation and distort the market of ideas.
Many times in my life, usually while pursuing one of my odd fascinations, someone will scoff and suggest that my pursuits are unworthy because “that’s not what people do”. I’ve learned to ignore them. Putting computers in the hands of the layman was “not what people do”, but Steve Jobs did it anyway. Putting nuclear reactors on submarines was “not what people do”, but Rickover did it anyway. He conceived the light water nuclear paradigm, and he brought nuclear technology from war to peace, from barbarism to munificence.

Mark Reed received his S.B. degree in Physics as well as his S.B. and S.M. degrees in Nuclear Science and Engineering at MIT, where he is currently pursuing a Ph.D. in Nuclear Science and Engineering. Mark has performed reactor modeling at TerraPower and risk assessment for the Yucca Mountain Nuclear Waste Repository at the U.S. Nuclear Regulatory Commission. 

 1. Atomic Energy Act of 1946 (Public Law 585, 79th Congress)
2. A. M. Weinberg. The First Nuclear Era: The Life and Times of a Technological Fixer. American Institute of Physics, New York (1994).
3. F. Duncan. Rickover: The Struggle for Excellence. Naval Institute Press. Annapolis, MD (2001).
4. “Science: The Man in Tempo 3”. Time Magazine. January 11, 1954.,9171,819338-2,00.html
5. History of the U.S. Nuclear Regulatory Commission
6.  Nuclear News: 13th Annual Reference Issue. The American Nuclear Society (2011).
7. R. Nixon: "Remarks at a Promotion Ceremony for Admiral Hyman G. Rickover.," December 3, 1973. Online by Gerhard Peters and John T. Woolley, The American Presidency Project.
8. S. Jobs: “Text of Steve Job’s Commencement Address” Stanford University News (2005).
9. T. Rockwell. The Rickover Effect: How One Man Made a Difference. U.S. Naval Institute Press (1992).