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Transcript of Nuclear Weapon
"What we know about nuclear weapon"
What is "nuclear weapon"?
Nuclear weapons are the most dangerous weapons on earth. One can destroy a whole city, potentially killing millions, and jeopardizing the natural environment and lives of future generations through its long-term catastrophic effects. The dangers from such weapons arise from their very existence. Although nuclear weapons have only been used twice in warfare—in the bombings of Hiroshima and Nagasaki in 1945—about 22,000 reportedly remain in our world today and there have been over 2,000 nuclear tests conducted to date. Disarmament is the best protection against such dangers, but achieving this goal has been a tremendously difficult challenge. 
BRAINSTORM on NW
SOKA High School
We have learned about various aspects of nuclear weapons.
Global Nuclear Vulnerability
History of Nuclear Weapons
Science of Nuclear Weapons
Types of A-bomb: Gun-Type and Implosion-Type
Current NW: Hydrogen Bomb
Cuban Missile Crisis
In October 1962 President John F. Kennedy, who was informed of a U-2 spy-plane’s discovery of Soviet nuclear-tipped missiles in Cuba, resolved immediately that this could not stand. Over an intense 13 days, the US and USSR were at the brink of mutual destruction, which was able to lead to the deaths of 100 million Americans and more than 100 million Russians.
The elements of NW
Uranium 235 or Plutonium 239
is used for nuclear weapons. Uranium is the heaviest element existing in nature.Plutonium is more heavy than Uranium, which can be created in nuclear power plants.
from : http://www.worldsciencefestival.com/2014/01/understanding_fukushima_part_1/
Since Uranium and Plutonium are heavy, they are unstable and easy to break. When one neutron hits an atom of U or Pu, the atom splits into two pieces and two or three neutrons. This is called
. Two pieces blow off in high speed, whose energy is the main actor of nuclear weapon. Neutrons released by nuclear fission hit another uranium/plutonium atom. This phenomenon is repeated numerous times, called
Nuclear chain reaction
is the smallest amount of fissile material needed for a sustained nuclear chain reaction. When you explode NW, you need to make U/Pu super critical mass, which means that its state is over a critical mass.
Scientists invented two types of A-bomb to make U/Pu a state of super critical mass. The graph below shows characteristics of each type.
Both U and Pu OK
Current technology uses not only fission, but also
of different isotopes of hydrogen.
Fusion requires high temperature;A-bomb is used as a detonator. As a result, nuclear fission of U-253/Pu-239 occurs first and then hydrogen fuses. Finally, the neutron released by fusion attacks to a U-258(different isotope of U-253) cover and causes nuclear fission again. The most powerful H-bomb is “Tsar Bomba,” which was tested by Soviet Union in 1961 and had a yield of 50 megatons, making it
more powerful than the Hiroshima bomb.
16-29 Oct 1962
24 Sep 1996
1 Jul 1968
6,9 Aug 1945
Russell-Einstein manifesto issued
Bertrand Russell, Albert Einstein and other leading scientists issue a manifesto warning of the dangers of nuclear war and urging all governments to resolve disputes peacefully.
Cuban Missile Crisis
A tense stand-off begins when the US discovers Soviet missiles in Cuba. The US blockades Cuba for 13 days.
Non-Proliferation Treaty is signed
Under the Non-Proliferation Treaty, non-nuclear-weapon states agree never to acquire nuclear weapons, and the nuclear-weapon states make a legal undertaking to disarm.
Total nuclear test ban is signed
The Comprehensive Nuclear Test Ban Treaty opens for signatures at the United Nations. France, the UK, Russia and the US all sign the treaty.
Manhattan Project established in US
The US sets up the Manhattan Project to develop the first nuclear weapon.
US drops atomic bomb on Hiroshima and Nagasaki
The US dropped a uranium bomb over the Japanese city of Hiroshima, and a plutonium bomb over Nagasaki.
In total, more than 200,000 people died, a lot of people even now are suffering from the damage of the atomic bomb.
Nuclear terrorism could include:
・Acquiring or fabricating a nuclear weapon
・Fabricating a dirty bomb
・Attacking a nuclear reactor, e.g., by disrupting critical inputs.
・Attacking or taking over a nuclear-armed submarine, plane or base
・A report by the US department of defense warned that the US and its allies “cannot be confident” about the security of their system in the event of a cyber attack by a well-resourced opponent. 
"The Comprehensive Nuclear-Test-Ban Treaty (CTBT) bans nuclear explosions by everyone, everywhere: on the Earth's surface, in the atmosphere, underwater and underground."
Since the Treaty is not yet in force, the organization is called the Preparatory Commission for the Comprehensive Nuclear-Test-Ban Treaty Organization (CTBTO).
The IAEA is widely known as the world's "Atoms for Peace" organization within the United Nations family. Set up in 1957 as the world's centre for cooperation in the nuclear field, the Agency works with its Member States and multiple partners worldwide to promote the safe, secure and peaceful use of nuclear technologies. 
ICAN is a global campaign coalition working to mobilize people in all countries to inspire, persuade and pressure their governments to initiate and support negotiations for a treaty banning nuclear weapons. The campaign was launched in 2007, and now has more than 400 partner organizations in 95 countries.
Since 1945 nuclear technology for civil and military uses has disseminated on a global scale. In 1945 only the United States possessed the technological capability to manufacture a nuclear weapon. By 1964, four other states had crossed the nuclear threshold, an event traditionally understood as the testing of a nuclear explosive devise.
All five states Proliferation of Nuclear Weapons (NPT) as Nuclear Weapon States, this being a state which "has manufactured and exploded a nuclear weapon or other nuclear explosive devise prior to 1 January 1967" 
Other states which have nuclear weapons are India, Pakistan, Israel and North Korea. India, Pakistan,and Israel have not signed NPT;North Korea withdrew from NPT in 2003.
 The Globalization of World Politics edited by John Baylis and Steve Smith
 Is the UK’s Trident nuclear program at risk from cyberattack?
BY KYLE ELLISON POSTED 27 NOV 2015
Temperature in the center of the fire ball caused by the atomic bomb in Hiroshima was over 1,000,000 ℃. Intense thermal rays from the fire ball made the ground 3000~4000℃.(The surface of the sun is 5700℃, while iron melts at 1500℃)
The people within 1.2km from the ground zero were burned completely, got damage in their internal organs. Most people died immediately or in a few days.
Most damage comes from the explosive blast. The shock wave of air radiates outward, producing sudden changes in air pressure that can crush objects, and high winds that can knock objects down. In general, large buildings are destroyed by the change in air pressure, while people and objects such as trees and utility poles are destroyed by the wind.
Unlike conventional weapons, nuclear weapons release ionizing radiation: particles and rays given off by radioactive materials. At high doses, radiation kills cells, damages organs and causes rapid death. At low doses, it can damage cells and lead to cancer, genetic damage and mutations. In human beings, it causes most types of leukemia, or blood cancer, as well as solid cancers such as thyroid, lung and breast cancers. 
Many Hibakusya were said to transmit their radiation illness to people.They were discriminated and have had psychological damage. Still now, some Hibakusya hide themselves being Hibakusha.
The first country to develop nuclear weapons and the only country to have used them in war. It spends more on its nuclear arsenal than all other countries combined.
Most of its nuclear warheads are deployed on submarines equipped with M45 and M51 missiles. One boat is on patrol at all times. Some warheads are also deliverable by aircraft.
It has a much smaller arsenal than the US and Russia. Its warheads are deliverable by air, land and sea. It appears to be increasing the size of its arsenal at a slow pace.
The second country to develop nuclear weapons. It has the largest arsenal of any country and is investing heavily in the modernization of its warheads and delivery systems.
It maintains a fleet of four nuclear-armed submarines in Scotland, each carrying 16 Trident missiles. It is considering whether to overhaul its nuclear forces or disarm.
It is making substantial improvements to its nuclear arsenal and associated infrastructure. It has increased the size of its nuclear arsenal in recent years.
It developed nuclear weapons in breach of non-proliferation commitments. It is increasing the size of its nuclear arsenal and enhancing its delivery capabilities.
It has a policy of ambiguity in relation to its nuclear arsenal, neither confirming nor denying its existence. As a result, there is little public information or debate about it.
It has a fledgling nuclear weapons programme. Its arsenal probably comprises fewer than 10 warheads. It is not clear whether it has the capability to deliver them.
(its first year to test a nuclear weapon )
(eg. NGO like ICAN)