Uranium comes in a number of isotopes, including U-238, U-235, and U-234. All of these isotopes contain 92 protons, but have differing neutron counts. Uranium-235 has played a hugely important role in nuclear fission, which is employed in both nuclear weapons and nuclear power plants. Uranium-235 has been responsible for some of humanities worst tragedies, but may be critical for our future survival...
All of the nuclear decay reactions shown in the chart below occur within the nucleus of the element. Many diagrams of elements, like the one of Uranium above, are not drawn to scale. In actuality, the nucleus to atom scale is closer to a grain of rice at the center of a football field. The massive amount of electron shielding means that the nucleus of one atom rarely interacts with the nucleus of another.
All nuclei decay at an average rate that is unique to that nuclear isotope. The different types of nuclear decay result in different particles, but they all come from within the nucleus. Alpha decay releases a particle with 2 protons and 2 neutrons (basically a He atom), Beta (-) decay is when a neutron decays and shoot out an electron to become a proton. Gamma decay releases energy in the form of a gamma ray.
The half-life of Carbon-14 is how we date almost all fossils and artifacts. By determining the concentration of C14 in a sample, we can reverse the half-life equation and determine the age of that sample.
Naturally, Uranium comes in a number of isotopes. U238 has a half-life of 4.5 billion years. U235 decays much faster, in only 700 million years while U234 has a half-life of 25,000 years. Although all of these isotopes have a relatively long half-life (compared to 5700 years for C14 or 23 x 10^-23 seconds for H7), it isn't their half-life that makes Uranium special. Part of what makes U235 so useful is the type of particle it emits during decay; an α particle. When U235 decays, it releases 2 neutrons and a sufficient amount of energy. These neutrons can go on to initiate rapid nuclear decay of surrounding U235 atoms, which release their own high energy neutrons capable of initiating even more decay. This causes a chain reaction know as nuclear fission, leading to a massive amount of energy released in a short time.
The Manhattan Project was a joint effort between the US, UK, and Canada during the events of WW2 meant to research nuclear warfare. A lot of influential scientists worked secretly develop the first atomic bomb. They produced the "Little Boy" and "Fat Man" bombs that were dropped on Hiroshima and Nagasaki in Japan, which played a large role in ending the war.
The U235 "Little Boy" bomb deployed in Hiroshima killed 140,000 people, and 3 days later the "Fat Boy" dropped in Nagasaki killed another 74,000. Japan's Emperor Hirohito announced the country's unconditional surrender in World War II in a radio address 9 days after the Hiroshima bomb citing the power of a "new and most cruel bomb."
The explosions at Hiroshima and Nagasaki were just the beginning of the tragedy. The U235 bombs not only released massive amounts of energy that decimated buildings, but also an extensive amount of gamma ray radiation. This radiation is absorbed by dust and debris, and spread across the entire continent. Exposure to gamma radiation caused radiation poisoning that killed tens of thousands, and impacted future generations to come.
Nuclear weapons like the Atomic Bomb release large amounts of Gamma Rays. These rays are extremely tiny compared to visible light, and can penetrate many materials and tissue. Gamma rays are small enough to actually get into your cells and excite the electrons within your DNA, causing permanent genetic damage. This leads to mutations within the affected tissue, and is especially dangerous if it alters your germ cells and can lead to teratogenic mutations within a fetus.
As Germany, Italy, and Japan surrendered and World War II concluded, a massive power vacuum opened up within Europe. A new super country, the Union of Soviet Socialist Republics (USSR) began to take control of resources in that void. Scared of the capabilities of the USSR, the United States ramped up Nuclear arms production in case it needed weapons for another WW2 like scenario. Afraid of the threat of United States weapons, the USSR began to manufacture their own Nuclear weapons. This arms race led to the production of thousands and thousands of nuclear warheads. With the widespread impacts of the A-bomb witnessed in Japan, the threat of planetary destruction was pervasive in political and popular culture. While no explosions ultimately came to pass, the "Cold War" between the USSR and US was a standoff that defined an era. By many accounts, the tension between Russia and US (and the political infiltration on both sides) indicates that the "Cold War" has still not ended.
The Geneva Convention is a set of rules that define rules of warfare, known as the International Humanitarian Laws. Certain weapons are banned by these laws because they cause indiscriminate damage to uninvolved and innocent civilians. By that standard, nuclear weapons SHOULD be banned, but as of today they are considered legal to stockpile for defense. Many nations around the world have built up stockpiles of nuclear weapons, including the US, Russia, China, UK, France, North Korea, India and Israel. When new nations threaten armament of these "weapons of mass destruction", the US is quick to disarm them through invasions and other military action.
The mechanics of a Nuclear Power plant are really not that complex. Nuclear power rods (such as those made from U235) undergo nuclear decay and emit energy. A nuclear weapon uses this burst of energy to stimulate other U235 atoms to undergo fission, starting a chain reaction that unleashes all at once. Unlike a nuclear weapon, however, these rods are separated with space and water, so instead of melting down, the decay is controlled and heats up that water to its boiling point. This steam is then used to spin a turbine, which generates energy. In a way, it's sort of like a hydroelectric dam, which instead uses the gravitational flow of water to push a turbine. The big smoke clouds you see coming from the cooling towers isn't actually smoke; it's just steam!
While the water that comes in contact with the nuclear rods does not itself get released as steam (the cooling water is a separate feed, as seen in the diagram above), there is still some concern that nuclear power plants can cause problems with drinking water. One source claims that as many as 75% US plants are aging, and the wear and tear has led to leaks of radioactive byproducts like Tritium.
While the claims of nuclear leakage are suspect, there are legitimate concerns that the thermal runoff from all of the cooling steam also increases the surrounding lake or ocean water temp and pH, impacting aquatic life. Poor Blinky.
When nuclear reactors have issues, usually because of human error, the effects can be catastrophic. Radiation leakage is not something to take lightly, so there are often mass evacuations and hugely expensive clean-up efforts. These rare events become global news and historic examples of industrial and scientific failure.
The International Nuclear and Radiological Event Scale (INES) was developed in 1990 to help give the public an idea of severe these events are. Small deviations in normal plant activity are a 0, while small incidents can range up to 3. When an accident occurs, it can lead to massive damage and loss of life, scaling up to a major accident at 7 that can potentially impact the entire globe.
In Pennsylvania, a secondary safety system allowed too much coolant liquid to drain. An automatic safety system was overridden by an employee, who thought the system was malfunctioning. Without coolant, the reactor had a partial meltdown, and radioactive gases and iodine were expelled into the atmosphere. It is considered the worst nuclear event to have occurred in the United States.
In one of the worst nuclear events in history, a reactor in northern Ukraine experienced a full meltdown. Because Ukraine was part of the Soviet Union at the height of the Cold War, many of the events leading to the meltdown are shrouded in secrecy. The town of Chernobyl was bathed in radioactive debris, which resulted in thousands of lives lost. The area is still under quarantine, 30 years later, uninhabited and abandoned.
A strong earthquake and subsequent tsunami started a chain reaction of power and containment system failures that led to a massive radioactive leakage into the Pacific Ocean in Japan. A 12 mile radius exclusion zone was made, with officials almost evacuating Tokyo 140 miles away due to the possible dangers. The radioactive leakage has been found in wildlife, including tuna, as far as California's coast.
The events that led to Chernobyl's disaster have been the speculation of many documentaries and even a critically acclaimed mini-series, but the exact details of how the meltdown came to pass are still unclear because of the secrecy of the Soviet Union. Low budgets, neglected safety protocols, and human error have been blamed, but ultimately, this event has been seared into our human conscience about the dangers of irresponsible nuclear power use. The reactor cores, made of Uranium-235, spread out as a dust cloud across the entire region, raining down on wildlife and citizens. As it was phrased in the docu-series, this Uranium was effectively tiny bullets piercing the DNA of any in it's path. Thousands of lives were lost within days to weeks from the rapid onset of cancer or other full body shut-down due to radiation poisoning. An active effort has been made to seal off the factory ruins, but the surrounding area is still highly radioactive and limited access is strictly monitored by the Ukraine government and military.
The material within the reactor become so hot during the Chernobyl meltdown that it flowed out as a lava-like material, traveled nearly 6.6 ft through piping, and cooled off as a wrinkly mass resembling an elephant's foot.
The elephant's foot is made of Silicon Dioxide, Uranium, Titanium, Zirconium, Magnesium and Graphite. It has been unresponsive to drilling, but has been able to be damaged by armor piercing rounds using an AK-47. It is still warm.
When the mass was first found, it had a radioactivity level of 8000 Roentgens, or 80 grays per hour. Spending only 30 seconds near it will result in dizziness and fatigue. Two minutes near it and your cells will begin to hemorrhage. By the time you hit the five-minute mark, you're a goner (50/50 chance of mortality).
"I'm told it's the equivalent of a chest X-ray"
We measure radiation in various scales; rad and gray scales measures the amount of radiation energy absorbed by a mass. The older unit, Roentgens, monitored the amount of electric charge freed by radiation from a certain mass of air, which did not accommodate for the variable absorption rates of other materials like human tissue. The REM and sivert are a measurement of the biological damage imposed by some dose of radiation exposure.
Please refer to VOD 45 (above) for a video tutorial on how to complete the following activities.
Simulate the half-life decay of Uranium-235 using coin flips or candy (Lab 2). Every half-life should lead to approximately 50% of that sample undergoing radioactive decay. Starting with at least 50 samples, emulate this decay by flipping a coin/candy 50 times. Record the number of heads, and repeat the flipping experiment with that number of remaining "isotopes". Repeat the trials until you flip 0 heads (and all of the sample has decayed). Because of the 50/50 probability of landing a heads, each trial is equivalent to a half-life time period (700 million years for Uranium-235) and your resulting graph should be similar to the exponential decay shown below.
With energy requirements going up and green house gasses also threatening climate collapse, there is an increased pressure to rely on alternative energy sources. Nuclear power has the potential to be an excellent power source, but it also has had historical issues that make citizens wary about the dangers of nuclear power plants. Even today, Nuclear energy is a big political and social issue that might have a significant impact on our lives in the coming decades.
While California is considered one of the leaders of environmental science and regulation, policy has been implemented to close most of the operating power plants in the state. San Onofre was shutdown in 2013, and Diablo Canyon Power Plant was slated to be closed in 2024. Pacific Gas and Electric (PG&E) have applied for a license renewal of the plant citing multiple benefits to the environment and the community. As of 2022, Newsom has signed orders to keep the plant open.
How do we filter out opinions from facts? How do we make a choice and support a side of this argument? Logic? Emotion?
ChatGPT Essay Production: Create an account on OpenAI to access ChatGPT. Submit a prompt to ChatGPT for a pro-nuclear essay (do not use the exact same prompt as listed here). Copy the results of the essay and combine both into a Google Doc. Share and insert both documents here. (1 pt) Pro-nuclear prompt, (1 pt) anti-nuclear prompt, (1 pt) pro-nuclear essay, (1 pt) anti-nuclear essay.
Evidence of AI Analysis: Use Scribbr AI Writing Check Tool to verify the pro-nuclear essay is AI generated (1 pt) and the anti-nuclear essay is AI generated (1 pt). Snip a screenshot of each and link the pictures here.
YOU ARE RESPONSIBLE FOR WRITING YOUR OWN ESSAY THAT ANALYZES BOTH CHATGPT ESSAYS. The requirements for the meta-analysis essay are below:
Meta-persuasion: Read both the pro-nuclear and anti-nuclear essay. Evaluate which argument you think is more compelling. WHY do you think that argument is more compelling? Is it a logical argument (compelled by facts, statistics, and evidence) or an emotional argument (based on fear, uncertainty, and doubt)? In politics and other areas of debate, what patterns do you notice for those arguments (logic vs emotion)? Craft a 3500-character analysis essay expressing your thoughts on these issues.
(1 pt) Evidence of non-AI Essay: Run your essay through the AI Writing Tool to verify the content of your essay is human-made.
If unable to provide this evidence, the following points will NOT be given.
(1 pt) Evidence of word/character count (Google Docs Word Count Screenshot)
(7 pts) Length: 3500 characters. 500 characters = 1 point.