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Thanks for sticking around for the conclusion, if you'll pardon the express. From the comments received yesterday, I see this conclusion is more in order than I realized at first. I trust this will clear up some of the confusion.
The world’s first nuclear power plant generated electricity in Obninsk in the Soviet Union on June 27, 1954. The capacity was only five megawatts, small by today’s standards, with most reactors now exceeding 1,000 megawatts. This power plant was shut down in May, 2002 because, as Russian Mayak Radio reported, its further operation became pointless. The radio station reported that the reactor had come to the end of its life after almost fifty years in operation.
The world’s first nuclear-powered submarine, the Nautilus, was launched in January, 1955. Nautilus' nuclear generator allowed it to dive longer, faster, and deeper than any submarine before it. Nautilus continued to break records in 1958 by becoming the first vessel to cross the North Pole. Decommissioned in 1980, the submarine was converted into a museum in 1985.
In 1955 the Atomic Energy Commission announced the beginning of a cooperative program between government and industry to develop nuclear power plants. Arco, Idaho (population 1,000) became the first U.S. town powered by nuclear energy. An experimental reactor, BORAX III, provided energy for the first U.S. nuke town. The power was generated at the Idaho National Energy Laboratory.
This same year the United Kingdom announced its decision to develop thermonuclear weapons. A few months later, the United Nations sponsored the first international conference on what they termed the “peaceful” uses of nuclear energy, a decision reached and announced in Geneva, Switzerland.
This may be a good place to point out the different types of reactors in existence.
The first type is the Pressurized Water Reactor. In the PWR the water which passes over the reactor core to act as moderator and coolant does not flow to the turbine, but is contained in a pressurized primary loop. The primary loop water produces steam in the secondary loop which drives the turbine. Put simply, water gets hot, converts to steam, and the steam powers the turbine which in turn generates electricity. The obvious advantage to this is that a fuel leak in the core would not pass any radioactive contaminants to the turbine and condenser.
Second is the Boiling Water Reactor. In the BWR, the water which passes over the reactor core to act as moderator and coolant is also the steam source for the turbine. While this seems more efficient, the disadvantage is that any fuel leak might make the water radioactive and that radioactivity would reach the turbine and the rest of the loop.
In the Pressurized Water Reactor, the water which flows through the reactor core is isolated from the turbine. But the Gas-Cooled Reactor (GFR) system features a fast-neutron-spectrum, helium-cooled reactor and closed fuel cycle. The GFR uses a direct-cycle helium turbine for electricity generation, or can optionally use its process heat for production of hydrogen. Through the combination of a fast spectrum and full recycle of actinides (such as Uranium), the GFR minimizes the production of long-lived radioactive waste. The GFR’s fast spectrum also makes it possible to use available fissile and fertile materials (including depleted uranium) much more efficiently than thermal spectrum gas reactors with once-through fuel cycles. Several fuel forms are candidates that hold the potential for operating at very high temperatures and to ensure an excellent retention of fission products: composite ceramic fuel, advanced fuel particles, or ceramic-clad elements of actinide compounds. Core configurations may be based on pin-or plate-based assemblies or on prismatic blocks. The GFR reference has an integrated, on-site spent fuel treatment and refabrication plant.
Russia holds an unintentional monopoly on the Light Water Graphite Reactor. The Soviet designed RBMK is a pressurized water reactor with individual fuel channels which uses ordinary water as its coolant and graphite as its moderator. It is very different from most other power reactor designs in that it was intended and used for production of both plutonium and power. The combination of graphite moderator and water coolant is found in no other power reactors. The design characteristics of the reactor were shown, in the Chernobyl accident, to cause instability when at low power. This was due primarily to control rod design and a positive void coefficient.
The Fast Neutron Reactor, the final major type, more deliberately use the uranium-238 as well as the fissile U-235 isotope used in most reactors. If they are designed to produce more plutonium than they consume, they are called Fast Breeder Reactors (FBR). But many designs are net consumers of fissile material, including plutonium. Fast neutron reactors also can burn long-lived actinides which are recovered from used fuel out of ordinary reactors.
What constitutes a nuclear accident has never been agreed upon, not even by nuclear physicists or the various Atomic Energy agencies throughout the world. But we take “accident” to mean that something dangerous happened that was not planned. With that view in mind, here is an incomplete list—incomplete partly because not all accidents are likely to have been reported and partly because a list of all accidents would require a separate book. We focus here on the most significant or horrendous events.
A container of uranium hexafluoride exploded on September 2, 1944, in the Oak Ridge transfer room, killing Peter N. Bragg, Jr., and Douglas P. Meigs and injuring three others. A steam pipe exploded and the incoming water vapor combined with the uranium compound to form hydrogen fluoride, a dangerous acid, which all five inhaled. Bragg and Meigs died from whole-body acid burns.
Shortly after the Hiroshima and Nagasaki bombs were detonated in August 1945, Harry K. Daghlian, Jr., working at the Los Alamos Omega Site, accidentally created a supercritical mass when he dropped a tungsten carbide brick onto a plutonium core. He removed the piece, but was fatally irradiated in the incident.
It was in November, 1950, when a B-50, returning one of several U.S. Mark IV bombs secretly deployed in Canada, developed engine trouble and jettisoned the weapon at 10,500 feet. The bomb, which carried some uranium but not its plutonium core, was set to self-destruct at 2,500 feet and dropped over the St. Lawrence River off Rivre du Loup, Quebec. The explosion shook area residents and scattered nearly 100 pounds of uranium.
During the early morning of March 1, 1954, a Japanese fishing boat, the Fukuryu Maru, or Lucky Dragon, and its crew witnessed what they thought was the sun rising to the west of them as they sailed in the Pacific Ocean. That struck the more alert of them as unlikely, what with the sun being in the habit of rising in the east. What they were actually seeing was the 12 Megaton detonation of the Hydrogen “Bravo” Bomb at the Bikini Atoll, eighty-five miles away. Several hours later, white ash began to fall like snow onto their ship. Many of the crew members, thinking they had come upon nonmelting snowflakes, began gathering the ash into bags as souvenirs. Before the actual sun set, the entire crew had fallen ill. (The 86 residents of Rongelap Atoll had similar experiences from their own deadly snow.) The twenty-three crew members were hospitalized in Japan and one later died of kidney failure due to being exposed to radiation. Not surprisingly, the incident caused a rift in relations between Japan and the United States because the U.S. did not warn Japan or any other country of the bomb’s testing, leaving the Lucky Dragon exposed to the fallout. The U.S. issued an apology and paid $2 million in compensation. The twenty-three crewmen were among 264 people accidentally exposed to radiation because the explosion and fall-out had been far greater than expected. The original natives were granted $325,000 in compensation and returned to Bikini in 1974 from which they were again evacuated four years later when new tests showed high levels of residual radioactivity in the region. Twenty-three nuclear tests were carried out at Bikini between 1946 and 1958.
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