In 1943 the US government established a nuclear research site in south-central Washington State at the town of Hanford on the Columbia River. That area had been used by Native American tribes for thousands of years and was the location for a reservation. The Yakima Indians were moved to another reservation west of the old reservation in 1943 to make way for the construction of the Hanford nuclear site.
On March 11, 2011 a tsunami was triggered by a powerful earthquake off the northeast coast of the Japanese island of Honshu. The huge wave crashed into the coastal Fukushima Number 1 nuclear power plant in Okuma, Fukushima Prefecture and caused a major nuclear disaster.
The Daiichi plant contains six GE boiling water reactors operated by the Tokyo Electric Power Company. The plant was started operation 1971 and ultimately generated almost five gigawatts of electrical power making it one of the fifteen biggest commercial nuclear power plants in the world.
On March 11, 2011 reactors 5 and 6 were in what is called cold shutdown where the pressure of the coolant is at regular sea level atmospheric pressure and the temperature is under two hundred degrees Fahrenheit. Reactor 4 had been defueled (had its fuel removed.)
Following the earthquake, reactors 1, 2 and 3 automatically shut down and emergency diesel generators switched on to provide electricity for reactors controls and coolant circulation pumps. The tsunami caused by the earthquake hit the site and flooded the rooms containing the emergency generators. It also severed the connection of the plant to the electrical power grid. Access to the site was inhibited by the flooding. Newer generators had been built above the flood zone but their connection to the reactors was not protected and was flooded, preventing their use. Attempts to bring in mobile generators failed because they could not be connected to the site power grid.
In April of 1986 there was a major nuclear accident at the Chernobyl nuclear power plant in Ukraine about two miles Prypiat, a city of about fifty thousand people on the Dnieper river near border with Belarus Ukraine was part of the Soviet Union at that time and the power plant was under the direct control of authorities in Moscow. As with Kyshtym, there was not enough attention paid to safety systems and procedures.
The Chernobyl power plant contained 4 reactors built between 1970 and 1983 based on a unique Soviet boiling water reactor design. Ordinary water was used as a coolant with graphite acting as a neutron moderator. Control rods were raised or lowered to control the power output of the reactors.
As the reactor heats up, bubbles or voids of steam reduce the density of the water in the core which causes a drop in neutron absorption and an increase in the reactivity of the core. In this particular reactor design, the amount of bubbles or the void coefficient has a very strong influence over reactor temperature and output.
On April 25 the operators were preparing the reactor number 4 for a test of the turbines ability to continue to spin and drive the circulation pumps after main electrical power was shut off. Early on April 26 automatic shut down mechanisms were disabled before the test.
In 1957, there was a serious nuclear accident in Ozyorsk, Russia at the Mayak nuclear fuel reprocessing plant. Ozyosk was one of the "closed cities" that the Soviet Union built to carry out for highly classified research and industry. Ozyorsk was not on any public maps so the disaster has been referred to under the name of the nearest town that was on public maps, Kyshtym.
In 1957, there was a serious nuclear accident in Ozyorsk, Russia at the Mayak nuclear fuel reprocessing plant. Ozyosk was one of the "closed cities" that the Soviet Union built to carry out for highly classified research and industry. Ozyorsk was not on any public maps so the disaster has been referred to under the name of the nearest town that was on public maps, Kyshtym.
The International Atomic Energy Agency (IAEA) introduced the International Nuclear and Radiological Event Scale (INRES ) in 1990 to categorized nuclear accidents to assist in communicating the seriousness and dangers of such events. The scale is logarithmic like the Richter scale for earthquakes. This means that each step up the scale in ten times the intensity of the prior step.
The Three Mile Island Nuclear Generating Station is a commercial nuclear power plant. It is located on Three Mile Island in the Susquehanna River. The island is three miles downriver from the town of Middletown, Pennsylvania which is near the city of Harrisburg, Pennsylvania. There are two nuclear reactors referred to as Three Mile Island Unit 1(TMI-1) and Three Mile Island Unit 2 (TMI-2) at the station.
The boiling water reactor (BWR) design is used in about one third of the commercial power generation reactors in use in the world today. It is the second most popular reactor design behind pressurized water reactors. The BWR design was the result of collaboration between the Idaho National Laboratory and General Electric in the mid-1950s. Today, GE Hitachi Nuclear Energy is the main manufacturer of the BWRs.
Most of the hydrogen in the universe consists of a single proton orbited by a single electron and is also known as H-1 or protium. A small percentage of hydrogen atoms contain a neutron in the nucleus as well as the proton. This form of hydrogen is referred to as H-2, heavy hydrogen or deuterium. It is a stable atom like H-1. In the Earth's crust, for every six thousand four hundred and twenty H-1 atoms, there is a single H-2 atom.
