Uranium-235

Uranium is a nuclear reactive element that has had a big impact on human history

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...

Nuclear reactions are abnormal for chemistry because they don't involve electrons

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.

Nuclear decay is happening around us all the time, within almost every element.

It's as easy as α, β, ɣ

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 time it takes for a half of a sample of isotopes to undergo decay is known as its "half-life".

Gordan Freeman had to survive a nuclear experiment gone wrong in the Half-Life games. Those games were modded and went on to become Counterstrike and Team Fortress series.

Carbon-14 decays at a constant rate with a half-life of about 5000 years. That means that you'll lose half of the remaining C14 every 5000 years. (1/2) of the sample will exist in 5000 years, (1/2)*(1/2) will exist in 10000 years, (1/2)*(1/2)*(1/2) will exist in 15000 years...

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.

The half-life of Uranium-235 is 700 million years

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.

This chain reaction of nuclear fission has been manipulated by humans for some powerful effects

The "Little Boy" bomb developed by the Manhattan Project used a hollow U235 bullet that could be launched into another another U235 cylinder to start the nuclear implosion.

Nuclear bombs use U235 to release massive amounts of energy once the fission chain reaction starts

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.

Niels Bohr (the guy who made the atomic model) worked on the secret project under a pseudonym.

The atomic bombs dropped on Hiroshima and Nagasaki were influential in ending WW2

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."

While the explosion killed 80,000 people in Hiroshima, radiation sickness was responsible for another 60,000 deaths

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.

The Atomic Bomb ended one war, but started another.

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.

And you get a nuke, and you get a nuke, and you get a nuke...

We don't know exactly how many nuclear warheads certain nations, like China, actually hold.

The war in Iraq was famously spurred because of the suspicion that Sadam Hussein had WMDs; he didn't but the US military is still there 20 years later.

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.

Uranium-235 holds the power to massive destruction, but nuclear power generated from Uranium-235 might be the best chance we have for clean energy that will save us from imminent climate collapse.

How does a Nuclear Power Plant work?

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!

The Springfield Power Plant had many safety issues and was hit with 342 violations during one surprise inspection.

Blinky, the 3 eye fish, may have been a result of Tritium, a nuclear isotope of Hydrogen.

Are Nuclear Power Plants safe?

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.

Modern nuclear power plants are mostly safe. But when things go wrong, they can go REALLY wrong.

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.

INES 5

1979: Three Mile Island

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.

INES 7

1986: Chernobyl

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.

INES 7

2011: Fukishima

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.

Chernobyl is anticipated to be unsafe for habitation for the next 20,000 years.

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.

Almost all of the first responders to Chernobyl died due to Acute Radiation Syndrome (ARS) that caused severe skin burns and shut down of major organ systems. Many of the patients were treated in a Moscow hospital, but nothing could be done to save them. Their bodies are buried in lead coffins to prevent the spread of radiation.

In 2018, construction of the New Safe Confinement was completed, which is designed to confine the radioactive remains of reactor 4 for the next 100 years. The dome replaces the quickly assembled "sarcophagus" that was put up in 1986 for the same containment purposes. The walls of the dome are 10 meters thick and are made of steel and other dense materials.

The "Elephant's Foot" is a large mass of corium formed under reactor 4, one of the most radioactive places on Earth.

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).

for nuclear plants ai

Older radiation meters used Roentgens to measure the exposure of radiation based on your time in that area (R/hr). Many of the dosimeters at Chernobyl had a cap of 3.6 Roentgen and were unable to measure the huge amount of radioactivity accurately.

"I'm told it's the equivalent of a chest X-ray"

Rads, Grays, Siverts, Roentgens, and REMs

1 rad = 0.01 Gy = 0.01 J/kg

1 Sv = 100 rem

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.

<0.01 rad: exposure from a chest or spine xray

25 rad: lowest dose to cause clinically observable blood changes

200 rad: local dose for onset of erythema in humans

400 rad: whole body LD50 for acute radiation syndrome in humans

1 krad: whole body LD100 for acute radiation syndrome in humans[7]

1 to 20 krad: typical radiation tolerance of ordinary microchips

4 to 8 krad: typical radiotherapy dose, locally applied

10 krad: fatal whole-body dose in 1964 Wood River Junction criticality accident[8]

1 Mrad: typical tolerance of radiation-hardened microchips

ANALYSIS "HUMAN"

essay analysis "human"