Question:  Walter Henry Zinn designed and built several new reactors, including one that produced sufficient electricity to illuminate four what?
Context: Gen4 Energy, Inc (formerly Hyperion Power Generation, Inc.) is a privately held corporation formed to construct and sell several designs of relatively small (70 MW thermal, 25 MW electric) nuclear reactors, which they claim will be modular, inexpensive, inherently safe, and proliferation-resistant.  According to news coverage, these reactors could be used for heat generation, production of electricity, and other purposes, including desalinization. Winson Engineering was a British manufacturer of narrow gauge and miniature railway steam locomotives and rolling stock during the 1990s.  It built several new locomotives for heritage railways as well as undertaking major rebuilds of existing locomotives. MH-1A was the first floating nuclear power station.  Named "Sturgis" after General Samuel D. Sturgis, Jr., this pressurized water reactor built in a converted Liberty ship was part of a series of reactors in the US Army Nuclear Power Program, which aimed to develop small nuclear reactors to generate electrical and space-heating energy primarily at remote, relatively inaccessible sites.  Its designation stood for "mobile, high power".  After its first criticality in 1967, MH-1A was towed to the Panama Canal Zone that it supplied with 10 MW of electricity from October 1968 to 1975.  Its dismantling was started in 2014 and it is anticipated to be completed in under four years. The nuclear power debate is a long-running controversy about the risks and benefits of using nuclear reactors to generate electricity for civilian purposes.  The debate about nuclear power peaked during the 1970s and 1980s, as more and more reactors were built and came online, and "reached an intensity unprecedented in the history of technology controversies" in some countries.  Thereafter, the nuclear industry created jobs, focused on safety and public concerns mostly waned.  In the last decade, however, with growing public awareness about climate change and the critical role that carbon dioxide and methane emissions play in causing the heating of the earth's atmosphere, there's been a resurgence in the intensity nuclear power debate once again.  Nuclear power advocates and those who are most concerned about climate change point to nuclear power's reliable, emission-free, high-density energy and a generation of young physicists and engineers working to bring a new generation of nuclear technology into existence to replace fossil fuels.  On the other hand, skeptics can point to two frightening nuclear accidents, the Chernobyl disaster in 1986 and subsequently the Fukushima Daiichi nuclear disaster, combined with escalating acts of global terrorism, to argue against continuing use of the technology.  The debate continues today between those who fear the power of nuclear and those who fear what will happen to the earth if we don't use nuclear power.  At the 1963 ground-breaking for what would become the world's largest nuclear power plant, President John F. Kennedy declared that nuclear power was a "step on the long road to peace," and that by using "science and technology to achieve significant breakthroughs" that we could "conserve the resources" to leave the world in better shape.  Yet he also acknowledged that the Atomic Age was a "dreadful age" and "when we broke the atom apart, we changed the history of the world." United States naval reactors are nuclear reactors used by the United States Navy aboard certain ships to generate the steam used to produce power for propulsion, electric power, catapulting airplanes in aircraft carriers, and a few more minor uses.  Such Naval nuclear reactors have a complete power plant associated with them.  All U.S. Navy submarines and supercarriers built since 1975 are nuclear-powered by such reactors.  There are no commissioned conventional (non-nuclear) submarines or aircraft carriers left in the U.S. Navy, since the last conventional carrier, USS "Kitty Hawk" , was decommissioned in May 2009.  The U.S. Navy had nine nuclear-powered cruisers with such reactors also, but they have since been decommissioned.  Reactors are designed by a variety of contractors, then developed and tested at one of several government (Department of Energy)-owned and prime contractor -operated facilities.  These facilities include Bettis Atomic Power Laboratory in West Mifflin, PA and its associated Naval Reactors Facility in Idaho, and Knolls Atomic Power Laboratory in Niskayuna, NY and its associated Kesselring site in West Milton, NY, all under the management of the office of Naval Reactors.  Sometimes there were full-scale nuclear-powered prototype plants built at the Naval Reactors Facility, Kesselring, and Windsor (in CT) to test the nuclear plants, which were operated for years to train nuclear-qualified sailors. Dresden Generating Station (also known as Dresden Nuclear Power Plant or Dresden Nuclear Power Station) is the first privately financed nuclear power plant built in the United States.  Dresden 1 was activated in 1960 and retired in 1978.  Operating since 1970 are Dresden units 2 and 3, two General Electric BWR-3 boiling water reactors. Dresden Station is located on a 953 acre site in Grundy County, Illinois, at the head of the Illinois River, near Morris, Illinois.  It is immediately northeast of the Morris Operation—the only de facto high-level radioactive waste storage site in the United States.  It serves Chicago and the northern quarter of the state of Illinois, capable of producing 867 megawatts of electricity from each of its two reactors, enough to power over one million average American homes. Experimental Breeder Reactor I (EBR-I) is a decommissioned research reactor and U.S. National Historic Landmark located in the desert about 18 mi southeast of Arco, Idaho.  At 1:50 p.m. on December 20, 1951, it became one of the world's first electricity-generating nuclear power plants when it produced sufficient electricity to illuminate four 200-watt light bulbs. Electricity had earlier been generated by a nuclear reactor on September 3, 1948 at the X-10 Graphite Reactor in Oak Ridge, Tennessee.  EBR-I subsequently generated sufficient electricity to power its building, and continued to be used for experimental purposes until it was decommissioned in 1964.  The Museum is open for visitors from Memorial Day to Labor Day. Covanta (formerly the Ogden Corporation) is a large global corporation that provides a variety of waste-management and incineration services.  Annually, Covanta's Energy-from-Waste (EFW) facilities, also known as waste-to-energy plants, burn approximately 20 million tons of waste from municipalities and businesses, while also generating sufficient electricity to power one million homes.  Covanta recycles approximately 500,000 tons of metal each year.  Through a large network of treatment and recycling facilities, the firm also provides industrial material management services to companies in various industries. Walter Henry Zinn (December 10, 1906 – February 14, 2000) was a nuclear physicist who was the first director of the Argonne National Laboratory from 1946 to 1956.  He worked at the Manhattan Project's Metallurgical Laboratory during World War II, and supervised the construction of Chicago Pile-1, the world’s first nuclear reactor, which went critical on December 2, 1942, at the University of Chicago.  At Argonne he designed and built several new reactors, including Experimental Breeder Reactor I, the first nuclear reactor to produce electric power, which went live on December 20, 1951. In Lithuania in 1978, construction began on two RBMK reactors (1,380 MWe net) with 30-year lives for the Ignalina Nuclear Power Plant.  The light-water, graphite-moderated reactors were of similar design as those at Chernobyl.  The nuclear power plant began operating in 1983.  The first reactor was decommissioned in 2004 and the second one in 2009.  Originally, Lithuania built these reactors to export electricity to its neighbours, with 42% of electricity exported in 1989.  This number fell through the 1990s as domestic demand increased.
Answer: 200-watt light bulbs.